Get behind on polishing it and it'll start to oxidize.
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Oil can leach into the grain, oxidize and blacken the wood.
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Smoothies made the right way don't separate or oxidize over time.
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The sooner we start digging, the sooner C will slowly oxidize away.
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If you blend them together, though, the herbs won't oxidize or lose any flavor.
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Additionally, he said, at room temperatures these polymers might rapidly oxidize into carbon dioxide.
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They turn black when the substances meet outside air and oxidize, Dr. Sarkar explained.
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Within days, my mane would oxidize into Roadkill Orange, alluring as a badger pelt.
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Other bacteria oxidize the milk fat, bestowing the aged carton with its fine, cringeworthy stench.
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Formulation breakthroughs that help keep certain ingredients that oxidize easily, like Vitamin C, more potent.
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An effective formula will stabilize the retinol so it doesn't oxidize and lose potency, Schueller notes.
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He's done everything from oxidize iron to pull out the individual chemicals in a glow stick.
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Don't just pour it right in (this will oxidize your beer); instead siphon your beer in slowly.
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Nonfat milk powder was used because the butterfat in the original powder would oxidize and turn rancid.
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However, centrifuge juicers likely don't get hot enough to actually destroy enzymes or oxidize nutrients, Foroutan explained.
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The 15-minute wait allows the color to oxidize so you can see how it will truly appear.
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Remember to crush and not mince, since that makes the garlic oxidize and taste slightly off, says Lang.
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And once you get air into the system, it can oxidize and can allow different bacteria to grow.
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Its vegetation holds on to billions of metric tons of carbon that could oxidize into heat-trapping gases.
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Over time, UV rays can oxidize the factory-applied clear coat on your headlights, rendering them dull and hazy.
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Another commonly used smart thread material, fiberglass, doesn't oxidize, but the fibers are stiff and the fabric loses breathability.
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Exposure to air causes this plug of gunk to oxidize and turn black, making it really tempting to mess with.
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But when they come into contact with light or air, they can oxidize and become irritating to eyes and skin.
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Rather than mulch, obliterate, and ultimately oxidize produce, they slowly pulverize it, leaving a lot of the good stuff intact.
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And metallic threads oxidize when exposed to moisture, be it a washing machine or the hand sweat of anxious soldiers.
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Bottle aging allows a spirit (or wine) to mellow and oxidize a little bit, but barrel aging radically changes the flavors.
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By suppressing the production of PPO, Arctic Apples age and brown at a slower rate — taking three weeks to fully oxidize.
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If he opened a bottle, though, that meant drinking all 2.63 milliliters, or pouring one glass and letting the rest oxidize.
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Generally brighter colors such as coppers and reds tend to oxidize quicker, which means more up keep and more time inthe salon.
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The salmon are kept chilled for the entirety of the catch cycle, which means the oil is much less likely to oxidize.
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Sunshine, ocean breezes, swimming pools, sweat, and air conditioning can all make a foundation crack, crease, pill, oxidize, or fall off completely.
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The conductive material used to create circuits can be prone to peeling, and specialized metallic fibers can oxidize when exposed to water.
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Two years have passed, though, and apparently if left unattended, bratty thrashing and pimply innuendo oxidize into something very much like the Chainsmokers.
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The direct competition between the teams this season, the fact that their fortunes are so inextricably intertwined, has served only to oxidize it.
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Stored standing up, the corks can dry and split over time, allowing air into the wine, which will oxidize it and ruin the flavor.
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The building's facade, made of zinc and copper, will oxidize over time, creating a patina delivering the look of a building from Williamsburg's past.
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To boost her appearance, she says she recently visited stem-cell scientist Dr. Augustinus Bader in Germany to oxidize her blood with anti-inflammatory peptides.
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The remainder sloped downhill — a negative for traditional Chinese sensibilities — which caused seeping water to warp the first home's walls and oxidize the marble floors.
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Since apples and sunchokes both tend to oxidize, says Sullivan, you'll want to make this salad just before serving to keep it looking its best.
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Over time, the copper exteriors will oxidize to a Statue of Liberty green — a slow-motion art project provided by the architects, and by nature.
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The beneficial compound needs to be activated to oxidize the protein, and those activating compounds are found at higher concentrations in heart patients, the researchers explained.
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It uses antioxidants to protect against the effects of these free radicals—"antioxidant" literally means "doesn't oxidize," where oxidizing is the chemistry word for losing electrons.
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The grass is dried—left to oxidize in the sun—and then boiled for at least eight hours so that it yields a thick, black tea.
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However, some of the milk fat did oxidize, the reaction that gives fats a rancid smell, though the treated milk didn't smell much different to the researchers.
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These unstable molecules are detrimental to the proper structure and function of cells throughout the body due to their ability to oxidize cells, known as oxidative stress.
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Let's toast to our good health with a probiotic fungus and oxidize a little yeast to make some of that old sweet sweet alcohols, acetic and other acids.
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It's an even grade of pink because the tuna was brown, and they oxidize the tuna—and that makes it that perfect level of pink—and they freeze it.
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It's as if he cast those late-night rides with his mother in metal, soundtracked it with a lifetime of subsequent friendships, then left it to oxidize in the woods.
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He found that a particular binding site for calcium in the heliobacteria's structure was identical to the position of the manganese cluster in photosystem II, which made it possible to oxidize water and produce oxygen.
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Cold-pressed juice doesn't oxidize nearly as quickly and has a shelf life of up to three days, which makes much more sense for a serious juice drinker who would like to do some meal prepping.
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We buy big packages of it because my husband insists on buying everything in its most cost-effective quantity, but I think the big bars oxidize by the end and the last part tastes far worse than the first.
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For one thing, it's a slow, or masticating, juicer, which means that rather than using high-speed blades that obliterate and oxidize anything that passes through them, it slowly pulverizes them, leaving a lot of the good stuff intact.
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Over time, a watch like the Black Bay Bronze ($3,975) will develop a rich, chocolaty patina like an antique statue, although its unique aluminum bronze alloy will never oxidize all the way to sea foam green like the Statue of Liberty.
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Samantha Lee, conservation manager at the World Wildlife Fund in Hong Kong, said that while palm oil is thought of as non-toxic, it would oxidize under Hong Kong's hot sun and it was not clear how harmful the new substance would become.
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Or sometimes I just dumped all the ingredients into my mini food processor and blasted the living daylights out of them, ignoring my better knowledge that extended blending would oxidize the fragile basil and the machine's tiny blades would never properly break down the nuts.
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At one point, Jobs and Ive became enthralled with anodized aluminum — which was used for the iMac, the iPod Nano, and later the iPhone — where the metal was put in an acid bath and electrified so its surface could oxidize and be changed into different colors.
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In other words, Mejuri is the startup king of fine jewelry you'll wear so often you'll forget to take it off before a shower (which is actually okay, since despite dropping only a few hundred on it, that 14-karat solid gold won't oxidize or discolor).
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Though the videos might inspire us to do the same with our own open comedones, which oxidize and turn black with exposure to oxygen, Beverly Hills-based dermatologist Ava Shamban, M.D., warns us that the extraction of less Instagram-worthy blackheads is also best left to the professionals.
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Here's what seems to be going on: This genetic mutation causes one component of hemoglobin—an iron-rich protein in red blood cells that carries oxygen around the body—to rapidly bind with oxygen, then oxidize, fall apart, and lose its heme iron; eventually the deformed cells are destroyed.
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But if you're not on hormonal birth control and you don't have other issues related to your period (such as PCOS, which can cause an unpredictable flow), here's what your menstrual blood is telling you: BrownAs mentioned above, brown blood is blood that's been sitting around long enough to oxidize.
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Chef knows that some of the newer, inexperienced cooks will occasionally undercook them and the artichokes will oxidize and have black spots at the center of their hearts; so, for Chef, it means extra work, extra waste, extra manpower, extra vigilance required when that home-run dish goes on the menu.
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TripWipes Anti-Bacterial Wipes — $225.99 See Details EdenPURE OxiLeaf G-215.99 Air Purifier If you're a pet owner, live in an old house, or just really appreciate a clean home, this EdenPURE OxiLeaf G-215.99 Air Purifier can help neutralize any odors in the air and oxidize germs on surfaces you touch.
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Hot tertiary air is then added to oxidize the remaining CO.
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For example, S. tokodaii is known to oxidize hydrogen sulfide to sulfate intracellularly.
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They conclude by using Thioredoxin that it is able to reduce the oxidize RsrA.
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From all of the SOB, the only group that directly oxidize sulfide to sulfate in abundance of oxygen without accumulating elemental sulfur are the Thiobacilli. The other groups accumulate elemental sulfur, which they may oxidize to sulfate when sulfide is limited or depleted.
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Despite its high reactivity, DMDO displays good selectivity for olefins. Typically, electron deficient olefins are oxidized more slowly than electron rich ones. DMDO will also oxidize several other functional groups. For example, DMDO will oxidize primary amines to nitro compounds and sulfides to sulfoxides.
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Cerium also forms cerium(III) oxide, , which is unstable and will oxidize to cerium(IV) oxide.
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Worse, the steel in ordinary bearings can oxidize (rust), producing a more abrasive compound which accelerates wear.
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It was reclassified as Alicyclobacillus in 2005. The name is derived from the Latin duplus (double), sulfur (sulfur), and oxido (oxidize), referring to the bacterium's ability to oxidize disulfide. A. disulfidooxidans was reclassified to Alicyclobacillus along with a strain of Sulfobacillus thermosulfidooxidans subsp. thermotolerans, which was classified as Alicyclobacillus tolerans.
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It has an estimated redox potential of ~1.3 V. This makes it possible to oxidize water during oxygenic photosynthesis.
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C. elegans can transform the nitrogen containing compound phthalazine It is also able to oxidize the organosulfur compound dibenzothiophene.
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The major function of the Mn(III) ions produced by MnP is oxidation and degradation of lignin. For this purpose, basidomycetes secrete MnP, rather than Mn(III), and the enzyme functions outside of the fungal cell. Mn(III) ions from MnP can oxidize the phenolic compounds in lignin directly, but they can also oxidize some organic sulfur compounds and unsaturated fatty acids. This oxidation forms thiyl and peroxyl radicals, which in the presence of O2, can oxidize lignin or react with water to form H2O2.
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Desulfobacter is a genus of bacteria from the family of Desulfobacteraceae.UniProt Desulfobacter has the ability to oxidize acetate to CO2.
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Furthermore, lactoperoxidase may contribute to the initiation of breast cancer, through its ability to oxidize estrogenic hormones producing free radical intermediates.
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John Heaton developed this process using nitrates to oxidize the 2-5% carbon in cast iron and convert it to steel.
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Some ovens provide various aids to cleaning. Continuous cleaning ovens have the oven chamber coated with a catalytic surface that helps break down (oxidize) food splatters and spills over time. Self-cleaning ovens use pyrolytic decomposition (extreme heat) to oxidize dirt. Steam ovens may provide a wet-soak cycle to loosen dirt, allowing easier manual removal.
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Procedures to prevent side reactions include the inverse addition of the enolate to MoOPH or careful control of the temperature (-78 to -20 °C). Notable miscellaneous reactions include MoOPH’s ability to oxidize alkylboranes directly to the alcohol with net stereo-retention. MoOPH has also been shown to oxidize N-trimethylsilyl amides directly to the hydroxamic acid.
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Pseudonocardia hydrocarbonoxydans is a bacterium from the genus of Pseudonocardia which has been isolated from air contaminant. Pseudonocardia hydrocarbonoxydans can oxidize hydrocarbons.
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These advantages are especially important for such coating materials as Ti, plastics, and metallic glasses, which rapidly oxidize or deteriorate at high temperatures.
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Acetogenic bacteria oxidize the acids, obtaining more acetate and either hydrogen or formate. Finally, methanogens (in the domain Archea) convert acetate to methane.
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In terms of electron donor, this group contains both organotrophs and lithotrophs. The organotrophs oxidize organic compounds, such as carbohydrates, organic acids (e.g., formate, lactate, acetate, propionate, and butyrate), alcohols (methanol and ethanol), aliphatic hydrocarbons (including methane), and aromatic hydrocarbons (benzene, toluene, ethylbenzene, and xylene). The lithotrophs oxidize molecular hydrogen (H2), for which they compete with methanogens and acetogens in anaerobic conditions.
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Some common metals oxidize extremely rapidly in air. Titanium and aluminium oxidize instantaneously in contact with the oxygen in the air. These metals form an extremely thin layer of oxidized metal on the surface which bonds with the underlying metal. This thin layer of oxide protects the underlying layers of the metal from the air preventing the entire metal from oxidizing.
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KHP is also a useful standard for total organic carbon (TOC) testing. Most TOC analyzers are based on the oxidation of organics to carbon dioxide and water, with subsequent quantitation of the carbon dioxide. Many TOC analysts suggest testing their instruments with two standards: one typically easy for the instrument to oxidize (KHP), and one more difficult to oxidize. For the latter, benzoquinone is suggested.
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Most illicit MDMA is synthesized using MDP2P (3,4-methylenedioxyphenyl-2-propanone) as a precursor. MDP2P in turn is generally synthesized from piperonal, safrole or isosafrole. One method is to isomerize safrole to isosafrole in the presence of a strong base, and then oxidize isosafrole to MDP2P. Another method uses the Wacker process to oxidize safrole directly to the MDP2P intermediate with a palladium catalyst.
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Vacuum furnaces make use of induction heating for the production of specialty steels and other alloys that would oxidize if heated in the presence of air.
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As a preventive measure sewage may be pretreated to increase pH or oxidize or precipitate the sulfides in order to inhibit the activity of sulfide utilizing bacteria.
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Using iron isotopes, an improvement in the understanding of the metabolic processes controlling iron oxidation and energy production in these organisms can be developed. Photoautrophic bacteria, which oxidize Fe(II) under anaerobic conditions, have also been studied. The Thiodictyon bacteria precipitate poorly crystalline hydrous ferric oxide when they oxidize iron. The precipitate was enriched in the 56Fe relative to Fe(II)aq, with a δ56/54Fe value of +1.5 ± 0.2‰.
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The air, the stirring, and the "boiling" action of the metal helped the oxidizing agents to oxidize the impurities and carbon out of the pig iron. As the impurities oxidize, they formed a molten slag or drifted off as gas while the retaining iron solidified into spongy wrought iron that floated to the top of the puddle and were fished out of the melt as puddle balls using puddle bars.
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5-HEDH is therefore hydroxy dehydrogenase that acts in a stereospecific manner to oxidize 5(S)-hydoxy residues in 6-trans unsaturated intermediate but not short-chain fatty acids.
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Pseudonocardia carboxydivorans is a bacterium from the genus of Pseudonocardia which has been isolated from soil in Seoul in Korea. Pseudonocardia carboxydivorans has the ability to oxidize carbon monoxide.
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The salts are dark red solids that dissolve in water to give highly alkaline and corrosive solutions. In air, these salts oxidize, and they evolve hydrogen sulfide by hydrolysis.
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Gallionellaceae comprises the genera Gallionella (type genus), Ferriphaselus, Sulfuriferula, Sulfurirhabdus and Sulfuricella. Sterolibacteraceae comprises the genera Sterolibacterium, Sulfurisoma, Denitratisoma, Sulfuritalea, Georgfuchsia, Sulfurisoma and Methyloversatilis. Members of the genus Nitrosomonas oxidize ammonium ions into nitrite, \- a process called nitrification - and are important in the nitrogen cycle. Other autotrophic genera such as Thiobacillus and Annwoodia oxidize reduced inorganic sulfur ions such as thiosulfate and sulfide into sulfate and have key roles in the sulfur cycle.
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H of Methanobacillus omelianskii oxidize ethanol into acetate and methane by a process called interspecies hydrogen transfer. Individuals of organism S are observed as obligate anaerobic bacteria that use ethanol as an electron donor, whereas M.o.H (Methanobacterium bryantii strain M.o.H) are methanogens that oxidize hydrogen gas to produce methane. These two metabolic reactions can be shown as follows: :Organism S: 2 CH3CH2OH + 2 H2O → 2 CH3COO− \+ 2 H+ \+ 4 H2 (ΔG°' = +19 kJ) :Strain M.o.
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RPE65 reverses the photoisomerization by converting an all-trans-retinyl ester to 11-cis-retinol. Most commonly, the ester substrate is retinyl palmitate. The other enzymes of the visual cycle complete the reactions necessary to oxidize and esterify all-trans-retinol to a retinyl ester (RPE65's substrate) and to oxidize 11-cis-retinol to 11-cis-retinal (the required photoactive visual pigment component). The reaction completed by RPE65 in the retinoid cycle.
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The fruits are high in pectin and therefore have good properties for preserves. However, they oxidize and lose color when not treated. Yellow fruit types are better suited to industrial use.
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Comamonas thiooxydans is a Gram-negative, rod-shaped bacterium from the genus Comamonas and family Comamonadaceae, which was isolated from a sulfur spring. C. thiooxydans has the ability to oxidize thiosulfate.
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Without lubricant, wear is increased when the small oscillatory movements occur again. It is possible for the resulting wear debris to oxidize and form an abrasive compound which further accelerates wear.
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The obvious requirement here is the ability for the semiconductor to oxidize the passivating atom or, Ec-Edb \+ χ > EI, with the semiconductor electron affinity χ and atom ionization energy EI.
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These microbes oxidize iron in environments that have a very low pH and are important in acid mine drainage. The second type of microbes oxidize ferrous iron at near-neutral pH. These micro-organisms (for example Gallionella ferruginea, Leptothrix ochracea, or Mariprofundus ferrooxydans) live at the oxic-anoxic interfaces and are microaerophiles. The third type of iron-oxidizing microbes are anaerobic photosynthetic bacteria such as Rhodopseudomonas, which use ferrous iron to produce NADH for autotrophic carbon dioxide fixation.
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Sulfolobus metallicus was first isolated in 1991 by doctors Gertrud Huber and Karl O. Stetter from solfataric fields in Iceland. The collected samples were grown on ore supplemented media under acidic conditions at the optimal temperature of 65⁰C. The archaea were routinely grown at the optimal temperature of 65⁰C on ore media. After Sulfolobus metallicus was shown to be able to oxidize sulfur compounds, researchers looked into its potential to oxidize reduced sulfur emissions.
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In taxonomy, Stappia is a genus of the Rhodobacteraceae.See the NCBI webpage on Stappia. Data extracted from the Some members of the genus (now transferred to Labrenzia) oxidize carbon monoxide (CO) aerobically.
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Dissimilatory oxidation converts sulfite to elemental sulfur. Sulfur oxidizing species include and the genera of Thiomicrospira, Halothiobacillus, Beggiatoa, Persephonella, and Sulfurimonas. Symbiotic species of the class Gammaproteobacteria, EpsilonproteobacteriaI can also oxidize sulfur.
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The Reed reaction is a chemical reaction that utilizes light to oxidize hydrocarbons to sulfonyl chlorides. This reaction is employed in modifying polyethylene to give chlorosulfonated polyethylene (CSPE), which noted for its toughness.
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Agroclavine belongs to the group of ergot alkaloids, such as ergotamine. Historically, the main use of agroclavine was to oxidize it to elymoclavine, which can then be used for ergot-based drug synthesis.
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This compound has been shown to oxidize many different contaminants but is notable for oxidizing chlorinated solvents such as perchloroethylene (PCE), trichloroethylene (TCE), and vinyl chloride (VC). However, potassium permanganate is unable to efficiently oxidize diesel, gasoline, or BTEX. Sodium permanganate is more expensive than potassium permanganate, but because sodium permanganate is more soluble than potassium permanganate, it can be applied to the site of contamination at a much higher concentration. This shortens the time required for the contaminant to be oxidized.
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The main metabolism is anaerobic oxidation of methane (AOM). AOM uses sulfate to oxidize methane into bicarbonate and forms hydrogen sulfide as a byproduct, and is described by the following equation: SO4^2- + CH4 -> HS^- +HCO3^- +H2O. It has also been proposed that methanogens can also oxidize methane into acetate or carbon dioxide, and not just bicarbonate. The rate of AOM is fairly slow, with turnover times for the coexisting sulfate and methane in the oceans ranging from weeks to years.
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These reactions are particularly important in the oceans. The archaea also appear crucial for ammonia oxidation in soils. They produce nitrite, which other microbes then oxidize to nitrate. Plants and other organisms consume the latter.
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Platinum hexafluoride in particular is notable for its ability to oxidize the dioxygen molecule, O2, to form dioxygenyl hexafluoroplatinate, and for being the first compound that was observed to react with xenon (see xenon hexafluoroplatinate).
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The process has the potential to oxidize and/or enhance naturally occurring aerobic degradation. Chemical oxidation has proven to be an effective technique for dense non- aqueous phase liquid or DNAPL when it is present.
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Most of the chemosynthetic autotrophic bacteria that can oxidize elemental sulfur to sulfate are also able to oxidize thiosulfate to sulfate as a source of reducing power for carbon dioxide assimilation. However, the mechanisms that they utilize may vary, since some of them, such as the photosynthetic purple bacteria, transiently accumulate extracellular elemental sulfur during the oxidation of tetrathionate before oxidizing it to sulfate, while the green sulfur bacteria do not. A direct oxidation reaction (T. versutus ), as well as others that involve sulfite (T.
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Photoautotrophic organisms are sometimes referred to as holophytic. Such organisms derive their energy for food synthesis from light and are capable of using carbon dioxide as their principal source of carbon. Oxygenic photosynthetic organisms use chlorophyll for light-energy capture and oxidize water, "splitting" it into molecular oxygen. In contrast, anoxygenic photosynthetic bacteria have a substance called bacteriochlorophyll – which absorbs predominantly at non-optical wavelengths – for light-energy capture, live in aquatic environments, and will, using light, oxidize chemical substances such as hydrogen sulfide rather than water.
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Microbial corrosion, or commonly known as microbiologically influenced corrosion (MIC), is a corrosion caused or promoted by microorganisms, usually chemoautotrophs. It can apply to both metallic and non-metallic materials, in the presence or absence of oxygen. Sulfate-reducing bacteria are active in the absence of oxygen (anaerobic); they produce hydrogen sulfide, causing sulfide stress cracking. In the presence of oxygen (aerobic), some bacteria may directly oxidize iron to iron oxides and hydroxides, other bacteria oxidize sulfur and produce sulfuric acid causing biogenic sulfide corrosion.
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Polaromonas hydrogenivorans is a Gram-negative, nonmotile, non-spore-forming, psychrotolerant bacterium from the genus Polaromonas, which was isolated from Alaskan forest soil. P. hydrogenivorans has the ability to oxidize hydrogen and its colonies are white.
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Reactions occurring at the counter electrode surface are unimportant as long as it continues to conduct current well. To maintain the observed current the counter electrode will often oxidize or reduce the solvent or bulk electrolyte.
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Collins reagent is the complex of chromium(VI) oxide with pyridine in dichloromethane. This metal-pyridine complex, a red solid, is used to oxidize primary alcohols to the aldehyde. This complex is a hygroscopic orange solid.
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The type of the mutation generated, however, may be dependent on the size and type of the adduct as well as the DNA sequence. Ionizing radiation and reactive oxygen species often oxidize guanine to produce 8-oxoguanine.
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Lemon juice is also used as a short-term preservative on certain foods that tend to oxidize and turn brown after being sliced (enzymatic browning), such as apples, bananas, and avocados, where its acid denatures the enzymes.
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Some Bacteria and Archaea can aerobically oxidize elemental sulfur to sulfuric acid. Acidithiobacillus ferrooxidans and Thiobacillus thioparus can oxidize sulfur to sulfite by means of an oxygenase enzyme, although it is thought that an oxidase could be used as well as an energy saving mechanism. For the anaerobic oxidation of elemental sulfur, it is thought that the Sox pathway plays an important role, although this is not yet completely understood. Thiobacillus denitrificans uses oxidized forms on nitrogen as terminal electron acceptor instead of oxygen, and A. ferrooxidans uses ferrous iron.
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Mars has almost no ozone layer, unlike the Earth, so UV light sterilizes the surface and produces highly reactive chemicals such as peroxides that would oxidize any organic chemicals.Hartmann, W. 2003. A Traveler's Guide to Mars. Workman Publishing.
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As such, aluminium (III) (Al^3+) is the much more common oxidation state for aluminium. Aluminium(I) compounds are both prone to disproportionation and difficult to prepare. At standard conditions, they readily oxidize to the aluminium(III) form.
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Many flavin-dependent enzymes are capable of oxidizing aliphatic nitro compounds to less-toxic aldehydes and ketones. Nitroalkane oxidase and 3-nitropropionate oxidase oxidize aliphatic nitro compounds exclusively, whereas other enzymes such as glucose oxidase have other physiological substrates.
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Simple phosphoranes typically hydrolyze and oxidize readily. They are therefore prepared using air-free techniques. Phosphoranes are more air-stable when they contain an electron withdrawing group attached to the carbon. Some examples are Ph3P=CHCO2R and Ph3P=CHPh.
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Annual energy captured by photosynthesis in green plants is about 4% of the total sunlight energy that reaches Earth. The energy transformations in biological communities surrounding hydrothermal vents are exceptions; they oxidize sulfur, obtaining their energy via chemosynthesis rather than photosynthesis.
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Aurantimonas manganoxydans is a Gram-negative, catalase- and oxidase-positive, non-spore-forming, motile bacteria from the genus of Aurantimonas which has the ability to oxidize Manganese. Aurantimonas manganoxydans was isolated from coastal water from Oregon in the United States.
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In 1922 Sendzimir married Barbara Alferieff. His first son Michael was born two years later. Designing and making his own machines, Sendzimir began experimenting with a new way to galvanize steel. Despite galvanization, the products still had a tendency to oxidize.
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Attempts to oxidize the NpOF4 to the maximal possible oxidation state Np(VIII) using krypton difluoride were unsuccessful. Neptunium hexafluoride reacts with carbon monoxide (CO) and light to form a white powder, presumably containing neptunium pentafluoride (NpF5) and an unidentified substance.
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Closely related to the methanogens are the anaerobic methane oxidizers, which utilize methane as a substrate in conjunction with the reduction of sulfate and nitrate. Most methanogens are autotrophic producers, but those that oxidize CH3COO− are classed as chemotroph instead.
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CES1 oxidizes the tertiary amide carbonyl carbons of edoxabans to carboxylic acid groups. CYP3A4 and CYP3A5 oxidize edoxabans via hydroxylation or demethylation. In hydrolysis, 2-amino-5-chloropyridine moiety of edoxaban is removed. Glucuronidation occurs to a lesser extend via glucuronosyltransferases.
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Filamentous carbon structures typically range between 10 and 500 nanometers in diameter. They are typically 10,000 nanometers (10 micrometers) long. They have a duplex structure. The outside of the structures is difficult to oxidize, but the core oxidizes more easily.
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Fenton's reagent is basically a mixture of ferrous iron salts as a catalyst and hydrogen peroxide. A similar sort of reaction can be made by mixing hydrogen peroxide with [ferric] iron (Iron III). When the peroxide is catalyzed by soluble iron it forms hydroxyl radicals(·OH) that oxidize contaminants such as chlorinated solvents, fuel oils, and BTEX. Traditional Fenton's reagent usually requires a significant pH reduction of the soils and groundwater in the treatment zone to allow for the introduction and distribution of aqueous iron as iron will oxidize and precipitate at a pH greater than 3.5.
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Recently, FMO enzymes have received a great deal of attention from the pharmaceutical industry both as a drug target for various diseases and as a means to metabolize pro-drug compounds into active pharmaceuticals. These monooxygenases are often misclassified because they share activity profiles similar to those of cytochrome P450 (CYP450), which is the major contributor to oxidative xenobiotic metabolism. However, a key difference between the two enzymes lies in how they proceed to oxidize their respective substrates; CYP enzymes make use of an oxygenated heme prosthetic group, while the FMO family utilizes FAD to oxidize its substrates.
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Because of the mitochondrial localization of MCT (to transport lactate into the mitochondria), LDH (to oxidize the lactate back to pyruvate), and COX (cytochrome c oxidase, the terminal element of the electron transport chain), Brooks et al. proposed the possibility of a mitochondrial lactate oxidation complex in 2006. This is supported by the observation that the ability of muscle cells to oxidize lactate was related to the density of mitochondria. Furthermore, it was shown that training increases MCT1 protein levels in skeletal muscle mitochondria, and that corresponded with an increase in the ability of muscle to clear lactate from the body during exercise.
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However, many of these problems were resolved in 1998. In that year, it was announced that researchers had managed to completely oxidize methanol using a series (or “cascade”) of enzymes in a biofuel cell. Previous to this time, the enzyme catalysts had failed to completely oxidize the cell's fuel, delivering far lower amounts of energy than what was expected given what was known about the energy capacity of the fuel. While methanol is now far less relevant in this field as a fuel, the demonstrated method of using a series of enzymes to completely oxidize the cell's fuel gave researchers a way forward, and much work is now devoted to using similar methods to achieve complete oxidation of more complicated compounds, such as glucose. In addition, and perhaps what is more important, 1998 was the year in which enzyme “immobilization” was successfully demonstrated, which increased the usable life of the methanol fuel cell from just eight hours to over a week.
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Important plant pathogens such as Xanthomonas axonopodis pv. citri (citrus canker), Pseudomonas syringae pv. actinidiae (kiwifruit Psa outbreak), and Xylella fastidiosa are also Gammaproteobacteria. Members of Chromatium are photosynthetic and oxidize hydrogen sulfide instead of water, producing sulfur as a waste product.
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Alicyclobacillus ferrooxydans is a species of Gram positive, strictly aerobic, bacterium. The bacteria are acidophilic and produced endospores. It was first isolated from solfataric soil. The species was first described in 2008, and the name refers to its ability to oxidize iron.
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It was believed that aerobic ammonia-oxidizing bacteria oxidize hydroxylamine to nitrite using octahaem hydroxylamine oxidoreductase (HAO). Recently, it was shown that the product of HAO is not nitrite but nitric oxide, which is further oxidized to nitrite by an unknown enzyme.
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There are neither side effects nor benefits from eating gold since it is a biologically inert metal and it is suitable for use in food since it does not oxidize or corrode in moist air, unlike many other metals. Cake with golden flakes.
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This process is better known as 'rusting', though it is distinct from the rusting of metallic iron. Many other metallic ores and minerals oxidize and hydrate to produce colored deposits, such as chalcopyrites or CuFeS2 oxidizing to copper hydroxide and iron oxides.
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109 In 1949 it was called the most noble (difficult to reduce) nonmetal as well as being a relatively noble (difficult to oxidize) metal.Haissinsky & Coche 1949, p. 400 In 1950 astatine was described as a halogen and (therefore) a reactive nonmetal.Brownlee et al.
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Some examples of these antagonists are caffeic acid, chlorogenic acid, and tannic acid. These compounds interact with the thiamine to oxidize the thiazole ring, thus rendering it unable to be absorbed. Two flavonoids, quercetin and rutin, have also been implicated as thiamine antagonists.
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"Endolithic Microorganisms in the Antarctic Cold Desert". Science: 215. 1045–1052. Mars has almost no ozone layer, unlike the Earth, so UV light sterilizes the surface and produces highly reactive chemicals such as peroxides that would oxidize any organic chemicals.Hartmann, W. 2003.
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The reaction is selective for oxidation of primary alcohols to aldehydes and generally does not oxidize secondary alcohols. Solutions for the Hoover–Stahl oxidation are commercially available from Millipore-Sigma, though the catalyst can be easily prepared in situ from common laboratory reagents.
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Water roots, which develop under flooded conditions, help support the tree and capture nutrients. These specialized roots tolerate high carbon dioxide concentrations, oxidize the rhizosphere, and carry on anaerobic respiration. Thus, they are the key to the species ability to thrive under flooded conditions.
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Reactive sulfur species (RSS) are a family of sulfur-based chemical compounds that can oxidize and inhibit thiol-proteins and enzymes. They are often formed by the oxidation of thiols and disulfides into higher oxidation states. Examples of RSS include persulfides, polysulfides and thiosulfate.
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EPA (1984). "Secondary Treatment Regulation: Special considerations." ; and "Treatment equivalent to secondary treatment." Where natural waterways are too small to rapidly oxidize primary treated sewage, the liquid may be used to irrigate sewage farms until suburban property values encourage secondary treatment methods requiring less acreage.
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Susannite is a lead sulfate carbonate hydroxide mineral. It has the formula Pb4SO4(CO3)2(OH)2. Susannite is the higher temperature phase of the two and forms above 80 °C when fluids oxidize the lead ore deposits. It is trimorphous with leadhillite and macphersonite.
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Members of the Desulfurobacteriales are strict anaerobes that exclusively oxidize hydrogen for energy, whereas those belonging to the Aquificales are microaerophilic, and capable of oxidizing other compounds (such as sulfur or thiosulfate) in addition to hydrogen.Reysenbach, A.-L. (2001) Phylum BII. Thermotogae phy. nov.
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This reforms the Fe(III) ion in the heme and releases a second water molecule. There are many deviations from this traditional catalytic cycle. MnP Compound I can be used to oxidize free Mn(II), ferrocyanide, as well as phenolics, and other aromatic compounds.
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The flavor of aseptically processed food products is minimally changed. Dairy products could have a cooked flavor because of exposure to sulfhydryl groups. The flavor is reduced during storage as the sulfhydryl groups oxidize. Severely treated milk could have a bitter flavor because of proteolysis.
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Since fast oxidizers oxidize food quickly, they are advised to rely more on fat protein efficient diet. This diet will help them to bear Hunger. Meanwhile, slow oxidizers are given carbohydrate efficient diet. Eating more proteins or fats can cause Abdominal pain in them.
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It does not oxidize on exposure to the air and is not readily acted on by chemical reagents. It is insoluble in water. It is soluble in dichloromethane, chloroform, benzene, diethyl ether, carbon disulfide and turpentine.Vaseline (Petroleum Jelly) Material Safety Data Sheet (MSDS) (June 15, 2007). MakingCosmetics.
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In the presence of a phase-transfer catalyst, alcohols are oxidized to the corresponding carbonyl compound (aldehyde or ketone). Sodium hypochlorite can also oxidize organic sulfides to sulfoxides or sulfones, disulfides or thiols to sulfonyl chlorides or bromides, imines to oxaziridines. It can also de-aromatize phenols.
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Some harmful gases can be neutralized through catalytic oxidation. A hopcalite can oxidize toxic carbon monoxide (CO) to harmless carbon dioxide (CO2). But the effectiveness of this catalyst strongly decreases with relative humidity increases. Therefore, there are some drier (desiccant) in the canisters (before such catalysts).
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After ruling out other causes, the authors tentatively attributed the positive results in the first trial to "chance". AstraZeneca then terminated the development programme. PBN and its derivatives hydrolyze and oxidize in vitro to form respectively MNP-OH (AKA, NtBHA) and its parent spin-trap MNP.
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AFCIs do not detect low line voltage. Low line voltage can cause electromechanical relays to repeatedly turn off and on. If current is flowing through the load contacts it causes arcing across the contacts as they open. The arcing can oxidize, pit and melt the contacts.
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For example, bivalves (clams) in the family Lucinidae host symbiotic bacteria that oxidize sulfides. Lucinid bivalves' gills house the bacteria, and the siphon supplies the bacteria and surrounding pore water with oxygenated water from above the sediment. Bacterial oxidation of the sulfides results in sulfates, reducing toxicity.
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Dye-sensitized solar cells or DSSCs use TiO2 and dyes to absorb the light. This absorption induces the formation of electron-hole pairs which are used to oxidize and reduce the same redox couple, usually I−/I3−. Consequently, a differential potential is created which induces a current.
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UV radiation is useful in preparing low-surface-energy polymers for adhesives. Polymers exposed to UV will oxidize, thus raising the surface energy of the polymer. Once the surface energy of the polymer has been raised, the bond between the adhesive and the polymer is stronger.
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Fruits have a very good flavor, a blend of sweet and sharp, preferable for eating, keeps shape in cooking. Flesh color is white, with a yellow tinge. The flesh does not oxidize quickly. The apple is crisp, but not too dense; it is easy to eat.
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In this method,Zn-Al metal target is sputtered in an oxygen atmosphere such that metal ions oxidize when they reach the substrates surface. By using a metal target instead of an oxide target, direct current magnetron sputtering may be used which enable much faster deposition rates.
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In both these animals, the symbiotic bacteria that live in the trophosome oxidize sulfur or sulfide found in the worm's environment and produce organic molecules by carbon dioxide fixation that the hosts can use for nutrition and as an energy source. This process is known as chemosynthesis or chemolithoautotrophy.
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Iron is almost always encountered in the oxidation states 0 (as in the metal), +2, or +3. Solid iron(II) salts are relatively stable in air, but in the presence of air and water they tend to oxidize to iron(III) salts that include hydroxide () or oxide () anions.
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Potassium dichromate is an oxidising agent in organic chemistry, and is milder than potassium permanganate. It is used to oxidize alcohols. It converts primary alcohols into aldehydes and, under more forcing conditions, into carboxylic acids. In contrast, potassium permanganate tends to give carboxylic acids as the sole products.
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Free radicals can oxidize LDL, and this is a key event in the formation of plaque in arteries, leading to heart disease and stroke.Bamm VV, Tsemakhovich VA, Shaklai N. Oxidation of low- density lipoprotein by hemoglobin–hemichrome. The International Journal of Biochemistry & Cell Biology. 2003;35(3) 349-58.
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Platinum catalysts are alternatives of automotive catalytic converters, carbon monoxide gas sensors, petroleum refining, hydrogen production, and anticancer drugs. These applications utilize platinum nanomaterials due to their catalytic ability to oxidize CO and NOx, dehydrogenate hydrocarbons, and electrolyze water and their ability to inhibit the division of living cells.
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Voet (2005), Ch. 17 Glycolysis. It is clear that using oxygen to completely oxidize glucose provides an organism with far more energy than any oxygen-independent metabolic feature, and this is thought to be the reason why complex life appeared only after Earth's atmosphere accumulated large amounts of oxygen.
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Nickel can enter into metal oxygen clusters with other high oxidation state elements to form polyoxometalates. These may stabilize higher oxidation states of nickel, or show catalytic properties. Nonamolybdonickelate(IV), [NiMo9O32]6− can oxidize aromatic hydrocarbons to alcohols. There is a dark brown heptamolybdonickelate(IV) potassium salt, K2H8NiMo7O28·6H2O.
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After formation of 5mCp-8-OHdG, the base excision repair enzyme OGG1 binds to the 8-OHdG lesion without immediate excision (see Figure). Adherence of OGG1 to the 5mCp-8-OHdG site recruits TET1, allowing TET1 to oxidize the 5mC adjacent to 8-OHdG. This initiates the demethylation pathway.
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Asphalt degradation is a growing concern. UV-rays oxidize the surface of the asphalt and produce a chalk-like residue. As plasticizers leach out of the asphalt, asphalt built-up roofs become brittle. Cracking and alligatoring inevitably follows, allowing water to penetrate the system causing blisters, cracks and leaks.
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According to theory, permanganate is strong enough to oxidize water, but this does not actually happen to any extent. Besides this, it is stable. It is a useful reagent, though with organic compounds, not very selective. Potassium permanganate is used as a disinfectant and water treatment additive in aquaculture.
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Western tastes, however, favoured the fully oxidized black tea, and the leaves were allowed to oxidize further. Yellow tea was an accidental discovery in the production of green tea during the Ming dynasty, when apparently careless practices allowed the leaves to turn yellow, which yielded a different flavour.
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They are of interest historically, and are also useful for hobbyists to form black oxide safely with little equipment and without toxic chemicals. Low temperature oxide, also described below, is not a conversion coating—the low-temperature process does not oxidize the iron, but deposits a copper selenium compound.
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The hydrogenation of 2-ethylanthraquinone is catalyzed by palladium. Hydrogenation produces both 2-ethylanthrahydroquinone and tetrahydroanthraquinone. The tetrahydro derivative of 2-alkylanthraquinone is easily hydrogenated but is more difficult to oxidize. The formation of the tetrahydro derivative can be suppressed through the selection of catalysts, solvents, and reaction conditions.
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These thin layers also keep pit corrosion from occurring, especially during exposure to salts that affect most other metals. However, despite the good corrosion resistance of aluminized steel, if the aluminium layer is disrupted and the steel is exposed, then the steel may oxidize and corrosion may occur.
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An acrylic cube specially prepared for element collectors containing liquefied xenon Xenon and the other noble gases were for a long time considered to be completely chemically inert and not able to form compounds. However, while teaching at the University of British Columbia, Neil Bartlett discovered that the gas platinum hexafluoride (PtF6) was a powerful oxidizing agent that could oxidize oxygen gas (O2) to form dioxygenyl hexafluoroplatinate (). Since O2(1165 kJ/mol) and xenon (1170 kJ/mol)have almost the same first ionization potential, Bartlett realized that platinum hexafluoride might also be able to oxidize xenon. On March 23, 1962, he mixed the two gases and produced the first known compound of a noble gas, xenon hexafluoroplatinate.
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If sodium sulfite is allowed to crystallize from aqueous solution at room temperature or below, it does so as a heptahydrate. The heptahydrate crystals effloresce in warm dry air. Heptahydrate crystals also oxidize in air to form the sulfate. The anhydrous form is much more stable against oxidation by air.
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In the nomenclature of haloperoxidase, bromoperoxidases classically are unable to oxidize chloride at all. For example, eosinophil peroxidase appears to prefer bromide over chloride, yet is not considered a bromoperoxidase because it is able to use chloride. Muricidae (was Murex) spp. snails have a bromoperoxidase used to produce Tyrian purple dye.
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Polyethylene and polystyrene are popular plastics used in beads. Polystyrene is very stable and can last for many decades as the beads lay in landfills. Eventually, it will begin to slowly oxidize via UV light from the sun. In contrast, polystyrene cannot decompose with UV radiation and biodegrades extremely slowly.
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F. placidus was the first archaeon discovered that can anaerobically oxidize iron coupled to the reduction of nitrate. It is thought that the presence of organisms similar to F. placidus in the ancient, anoxic Earth may have led to the formation of banded iron formations often found in ancient rocks.
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Almonds have high levels of polyunsaturated fats in them. Typically, the omega 6 fatty acids in almonds are protected from oxidation by the surface skin and vitamin E. When almonds are ground, this protective skin is broken and exposed surface area increases dramatically, greatly enhancing the nut's tendency to oxidize.
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For objects that have intricate detail like monstrances, gilding greatly reduces the need for cleaning and polishing, and so reduces the risk of damage. Ungilded silver would suffer oxidation and need frequent polishing; gold does not oxidize at all. The "gold" threads used in embroidered goldwork are normally also silver-gilt.
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When implanted on a surface, gold clusters catalyze oxidation of at ambient temperatures. Similarly gold clusters implanted on can oxidize at temperatures as low as 40K. Catalytic activity correlated with the structure of gold nanoclusters. A strong relationship between energetic and electronic properties with size and structure of gold nanoclusters.
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The most common phosphine ligands are of the type PR3. They are three-fold symmetric with equivalent substituents. Some routine phosphine ligands are triphenylphosphine and trimethylphosphine. The triarylphosphines are usually white shelf-stable solids, whereas the trialkylphosphines are colorless liquids that tend to air-oxidize to the corresponding phosphine oxides (R3PO).
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A. clavatus has the properties to oxidize tryptamine to indole acetic acid. It can absorb and collect hydrocarbons from fuel oil, incorporate metaphosphate and synthesize ethylene, clavatol and kojic acid. It is also responsible for the production of mycotoxins Patulin and sterigmatocystin. And has extremely high capacity for alcohol fermentation.
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Acetic acid bacteria (AAB) are a group of Gram-negative bacteria which oxidize sugars or ethanol and produce acetic acid during fermentation. The acetic acid bacteria consist of 10 genera in the family Acetobacteraceae. Several species of acetic acid bacteria are used in industry for production of certain foods and chemicals.
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Eosinophil peroxidase catalyzes the haloperoxidase reaction. EPO can take chloride, bromide and iodide as substrates, as well as the pseudohalide thiocyanate (SCN−). However, the enzyme prefers bromide over chloride, iodide over bromide and thiocyanate over iodide, with regard to reaction velocities. In fact, only myeloperoxidase can oxidize chloride with any considerable rate.
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This way, the beer does not oxidize and the quality of taste is preserved. A tap tube is delivered with each new keg for hygienic installation. All parts touching beer are renewed with every new keg, ensuring a hygienic experience and high-quality beer. The PerfectDraft tap unit requires only surface cleaning.
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In this process, Sulfate-reducing bacteria oxidize organic matter using sulfate, instead of oxygen. Their metabolic products include bicarbonate, which can neutralize water acidity, and hydrogen sulfide, which forms highly insoluble precipitates with many toxic metals. Although promising, this process has been slow in being adopted for a variety of technical reasons.
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H2SO5 has been used for a variety of disinfectant and cleaning applications, e.g., swimming pool treatment and denture cleaning. Alkali metal salts of H2SO5 show promise for the delignification of wood. It is also used in laboratories as a last resort in removing organic materials since H2SO5 can fully oxidize any organic materials.
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The excited electron and hole can reduce and oxidize, respectively, species having suitable redox potentials relative to the potentials of the valence and conduction bands. Semiconducting minerals with appropriate band gaps and appropriate band energy levels can catalyze a vast array of reactions, most commonly at mineral-water or mineral-gas interfaces.
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When fused with nitrate salts, tellurite salts oxidize to tellurates (). Upon acidification of aqueous solutions of tellurite salts, solid hydrated tellurium dioxide (TeO2) precipitates. This reaction allows the separation of tellurium from selenium since selenous acid remains soluble at low pH. The intermediate in the protonation occurs at oxygen to give [TeO2(OH)]−.
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Dechloromonas aromatica is a gram negative, facultative anaerobe bacterium from the genus of Dechloromonas which was isolated of the Potomac River sludge in the mid-Atlantic coast of the United States and occurs in environment soil. Dechloromonas aromatica has the ability to degrade benzene anaerobically, reduce perchlorate and oxidize chlorobenzoate, toluene and xylene.
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Orthodox processing is done either by machines or by hand. Hand processing is used for high quality teas. While the methods employed in orthodox processing differ by tea type, this style of processing results in the high quality loose tea sought by many connoisseurs. The tea leaves are allowed to completely oxidize.
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These enzymes can also N-acetylate 4-aminobiphenyl. N-Acetylated products are difficult to oxidize and because of this acetylation is considered a detoxification step for aromatic amines. Glucuronidation also represents a major metabolic pathway for carcinogenic aromatic amines. A certain human UGT catalyzes the formation of the N-glucuronide of 4-aminobiphenyl.
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Below 14.5% the yeast will not form its protective cap, and so the wine will oxidize to the point of becoming vinegar. Above 16% the flor cannot survive, and so the wine essentially becomes an oloroso.Robinson, J. (ed). The Oxford Companion to Wine, Third Edition, Oxford University Press, 2006, pp 664-665.
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The 5,10-methenyltetrahydromethanopterin hydrogenase (or Hmd), the so-called iron-sulfur cluster-free hydrogenase, is an enzyme found in methanogenic archea such as Methanothermobacter marburgensis. It was discovered and first characterized by the Thauer group at the Max Planck Institute in Marburg. Hydrogenases are enzymes that either reduce protons or oxidize molecular dihydrogen.
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The green, outer bacteria use light to oxidize sulfide into sulfate. The inner cell, which is not able to perform photosynthesis, reduces the sulfate into sulfide. These bacteria divide in unison, giving the structure a multicellular appearance which is highly unusual in bacteria.Postgate, John: "The Outer Reaches of Life", page 132-134.
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RuO4 is of specialized value in organic chemistry because it oxidizes virtually any hydrocarbon. For example, it will oxidize adamantane to 1-adamantanol. Because it is such an aggressive oxidant, reaction conditions must be mild, generally room temperature. Although a strong oxidant, RuO4 oxidations do not perturb stereocenters that are not oxidized.
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Prior to the 1960s, the oxidation of xenotoxic materials was thought to be completely accomplished by CYP450. However, in the early 1970s, Dr. Daniel Ziegler from the University of Texas at Austin discovered a hepatic flavoprotein isolated from pig liver that was found to oxidize a vast array of various amines to their corresponding nitro state. This flavoprotein named "Ziegler's enzyme" exhibited unusual chemical and spectrometric properties. Upon further spectroscopic characterization and investigation of the substrate pool of this enzyme, Dr. Ziegler discovered that this enzyme solely bound FAD molecule that could form a C4a-hydroxyperoxyflavin intermediate, and that this enzyme could oxidize a wide variety of substrates with no common structural features, including phosphines, sulfides, selenium compounds, amongst others.
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Chromatium is a genus of photoautotrophic Gram-negative bacteria which are found in water. The cells are straight rod-shaped or slightly curved. They belong to the purple sulfur bacteria and oxidize sulfide to produce sulfur which is deposited in intracellular granules of the cytoplasm.George M. Garrity: Bergey's Manual of Systematic Bacteriology. 2. Auflage.
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Additionally, current persulfate activation methods often stall resulting in sub-optimal results. These problems could be fixed by creating oxidants that are more stable and specifically targeted to contaminants so that they do not oxidize other substances. The delivery systems could also be improved so that the oxidants are sent to the correct locations.
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Electrolytically refined manganese chips and a 1 cm3 cube Manganese is a silvery-gray metal that resembles iron. It is hard and very brittle, difficult to fuse, but easy to oxidize. Manganese metal and its common ions are paramagnetic. Manganese tarnishes slowly in air and oxidizes ("rusts") like iron in water containing dissolved oxygen.
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Between 40 and 60% copper extraction was achieved in primary reactors and more than 90% extraction in secondary reactors with overall residence times of about 6 days. All of these microbes are gaining energy by oxidizing these metals. Oxidation means increasing the number of bonds between an atom to oxygen. Microbes will oxidize sulfur.
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A method for phenolic content quantification is volumetric titration. An oxidizing agent, permanganate, is used to oxidize known concentrations of a standard solution, producing a standard curve. The content of the unknown phenols is then expressed as equivalents of the appropriate standard. Some methods for quantification of total phenolic content are based on colorimetric measurements.
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Long-chain alcohol oxidase is one of two enzyme classes that oxidize long- chain or fatty alcohols to aldehydes. It has been found in certain Candida yeast, where it participates in omega oxidation of fatty acids to produce acyl-CoA for energy or industrial use, as well as in other fungi, plants, and bacteria.
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The JSB stain consists of two solutions which are used in sequence to stain various parts of the sample. The first solution consists of methylene blue, potassium dichromate, and sulfuric acid diluted in water. This solution is heated for several hours to oxidize the methylene blue. The second solution is eosin dissolved in water.
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Benzoyl peroxide and hydrogen peroxide are used as bleaching and "maturing" agents for treating flour to make its grain release gluten more easily; the alternative is letting the flour slowly oxidize by air, which is too slow for the industrialized era. Benzoyl peroxide is an effective topical medication for treating most forms of acne.
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As the TAE connector does not have gold contacts, the contacts may oxidize, which can cause sizzling and crackling noises in analog voice transmission. Looping the a2 and b2 wires out of the TAE is related to the routing the line through instruments in a house in order that no extension may overhear another.
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The location where glycolysis, aerobic or anaerobic, occurs is in the cytosol of the cell. In glycolysis, a six-carbon glucose molecule is split into two three-carbon molecules called pyruvate. These carbon molecules are oxidized into NADH and ATP. For the glucose molecule to oxidize into pyruvate, an input of ATP molecules is required.
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CdO is a basic oxide and is thus attacked by aqueous acids to give solutions of [Cd(H2O)6]2+. Upon treatment with strong alkaline solutions, forms. A thin coat of cadmium oxide forms on the surface of cadmium in moist air at room temperature. Cadmium will oxidize at room temperatures to form CdO.
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The cutting phase entails remaining in a net negative energy balance (calorie deficit). The main goal of cutting is to oxidize fat while preserving as much muscle as possible. The larger the calorie deficit, the faster one will lose weight. However, a large calorie deficit will also create the risk of losing muscle tissue.
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Oxidants such as permanganate and Fenton's Reagent are delivered as water-based solutions. These substances are injected into the aquifer and then allowed to propagate by gravity and water current. As contaminants are encountered, the substances oxidize them and purify the water. Ozone is delivered (sparged) as a gas in either a dry air or oxygen carrier gas.
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The enzyme is important for carotenoid biosynthesis during chloroplast biogenesis. In developing plastids, its activity prevents the over-reduction of the plastoquinone pool. Knockout plants for PTOX exhibit phenotypes of variegated leaves with white patches. Without the enzyme, the carotenoid synthesis pathway slows down due to the lack of oxidized plastoquinone with which to oxidize phytoene, a carotenoid intermediate.
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151 Eng. Rep. 1266, 8 M & W 806, Web. Pat. Cases 295 (Exch. 1841). Neilson upheld a patent on using heated air to oxidize carbon in cast iron in a Bessemer Converter against the claim that it was just a patent on the idea or principle that heating the injected air makes a blast furnace work better.
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Some strains are capable of 'aerobic denitrification', the complete dissimilation of nitrate to dinitrogen (or nitrous oxide) under aerobic growth conditions. The microbe also can oxidize ammonia to nitrite while growth on organic energy sources, a process known as 'heterotrophic nitrification'. Coupled to denitrification, heterotrophic nitrification allows for the complete transformation of ammonia to dinitrogen by a single organism.
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An aldehyde differs from a ketone in that it has a hydrogen atom attached to its carbonyl group, making aldehydes easier to oxidize. Ketones do not have a hydrogen atom bonded to the carbonyl group, and are therefore more resistant to oxidation. They are oxidized only by powerful oxidizing agents which have the ability to cleave carbon–carbon bonds.
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Rohde, J.-U., In, J.-H., Lim, M. H., Brennessel, W. W., Bikowski, M. R., Stubna, A., Munck, E., Name, W., Que, L., Science, 299, 1037-1039, 2003; High-valent iron bispidine complexes can oxidize cyclohexane to cyclohexanol and cyclohexanone in 35% yield with an alcohol to ketone ratio up to 4.Comba, P. et al.
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Free radicals and pro-oxidants in cigarettes damage blood vessels and oxidize LDL cholesterol. Only oxidized LDL cholesterol is taken-up by macrophages, which become foam cells, leading to atherosclerotic plaques. Cigarette smoke increases proinflammatory cytokines in the bloodstream, causing atherosclerosis. The pro-oxidative state also leads to endothelial dysfunction, which is another important cause of atherosclerosis.
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When salo has been aged too long or exposed to light, the fat may oxidize on the surface and become yellow and bitter-tasting. Though no longer fit for culinary use, the spoiled fat can be used as a water- repellent treatment for leather boots or bait for mouse traps, or it can simply be turned into homemade soap.
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The control of organic vapors is achieved by either destruction or collection. Afterburners are used downstream of rotary dryers and conveyor furnaces to destroy organic contaminants and oxidize carbon monoxide. Conventional afterburners are designed so that exit gas temperatures reach 1,400 °F to 1,600 °F. Organic destruction efficiency typically ranges from 95% to greater than 99%.
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While rising carbon dioxide levels caused increased global warming, the climate models of the Cretaceous period do not show such elevated global temperatures due to the Earth's carbon dioxide variations. Geologic records show evidence of dissociation of methane clathrates, which causes a rise in carbon dioxide, as the oxygen gas in the atmosphere will oxidize the released methane.
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Methylococcus capsulatus is an obligately methanotrophic gram-negative, non- motile coccoid bacterium. M. capsulatus are thermotolerant; their cells are encapsulated and tend to have a diplococcoid shape. In addition to methane, M. capsulatus is able to oxidize some organic hydrogen containing compounds such as methanol. It has been used commercially to produce animal feed from natural gas.
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This treated wood utilizes a fire retardant chemical that remains stable in high temperature environments. The fire retardant is applied under pressure at a wood treating plant like the preservatives described above, or applied as a surface coating. In both cases, treatment provides a physical barrier to flame spread. The treated wood chars but does not oxidize.
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In museum species, the pigments deepen with age because the copper begins to oxidize. These birds manage to maintain their colours throughout the year. The Knysna Loerie is thought to use its red wing feathers to escape predators. Indeed, when it flies, the predators tend to focus on the most visible colour and follow the red patch.
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Overflow metabolism refers to the seemingly wasteful strategy in which cells incompletely oxidize their growth substrate (e.g. glucose) instead of using the respiratory pathway, even in the presence of oxygen. As a result of employing this metabolic strategy, cells excrete (or "overflow") metabolites like lactate, acetate and ethanol. Incomplete oxidation of growth substrates yields less energy (e.g.
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Viologens are used in the negative electrolytes of some experimental flow batteries. Viologens have been modified to optimize their performance in such batteries, e.g. by incorporating them into redox-active polymers. Viologen catalysts have been reported to have the potential to oxidize glucose and other carbohydrates catalytically in a mildly alkaline solution, which makes direct carbohydrate fuel cells possible.
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On thermal stability of terbium tetrafluoride[J]. Zhurnal Neorganicheskoj Khimii, 1985, 30(10): 2530-2533. Terbium(IV) fluoride can oxidize cobalt trifluoride into cobalt tetrafluoride: : TbF4 \+ CoF3 → TbF3 \+ CoF4↑ It can fluoronate [60]fullerene at 320–460 °C. When terbium(IV) fluoride reacts with potassium chloride and fluorine, it can produce the mixed valence compound KTb3F12.
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Ifremeria nautilei attains a maximum dimension of 85 mm, which is larger than other abyssochroids (length usually under 20 mm). This species hosts symbiotic chemoautotrophic bacteria that oxidize sulfur from hydrothermal vents. This arrangement enables it to satisfy most of its metabolic requirements. This species is unique among the others in this superfamily in two respects.
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Methylacidiphilum fumariolicum is an autotrophic bacterium first described in 2007 growing on volcanic pools near Naples, Italy. It grows in mud at temperatures between 50 °C - 60 °C and an acidic pH of 2–5. It is able to oxidize methane gas. It uses ammonium, nitrate or atmospheric nitrogen as a nitrogen source and fixes carbon dioxide.
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Base metals oxidize and absorb into the cupel. The product of this cupellation (doré) is flattened and treated in nitric acid to remove silver. Precision weighing of metal content of samples and process controls (proofs) at each process stage is the basis of the extreme method precision. European assayers follow bullion traditions based in hallmarking regulations.
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Followed by nitrite oxidation by nitrite-oxidizing bacteria (NOB), which converts NO2− to NO3−. Ammonium and nitrite oxidizers have a high affinity for O2 and can use nanomolar concentrations of O2 to oxidize ammonium and nitrite. These small concentrations of O2 can be supplied by photosynthesis by Prochlorococcus spp. or by horizontal mixing by jets and eddies.
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When it reaches the atmosphere, weathering occurs; the sulfide minerals oxidize and form pink erythrite ("cobalt glance": Co3(AsO4)2·8H2O) and spherocobaltite (CoCO3). Cobalt is also a constituent of tobacco smoke. The tobacco plant readily absorbs and accumulates heavy metals like cobalt from the surrounding soil in its leaves. These are subsequently inhaled during tobacco smoking.
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Solvents are used to simply clean the surfaces of any contaminates or debris. They do not increase the surface energy of the adherend. To modify the surface of the adherend, acid solutions can be used to etch and oxidize the surface. These solutions must be carefully prepared in order to ensure good bonding strength is developed.
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Methylotrophic yeast metabolism differs from bacteria primarily on the basis of the enzymes used and the carbon assimilation pathway. Unlike bacteria which use bacterial MDH, methylotrophic yeasts oxidize methanol in their peroxisomes with a non-specific alcohol oxidase. This produces formaldehyde as well as hydrogen peroxide. Compartmentalization of this reaction in peroxisomes likely sequesters the hydrogen peroxide produced.
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Fermentation does not require oxygen. If oxygen is present, some species of yeast (e.g., Kluyveromyces lactis or Kluyveromyces lipolytica) will oxidize pyruvate completely to carbon dioxide and water in a process called cellular respiration, hence these species of yeast will produce ethanol only in an anaerobic environment (not cellular respiration). This phenomenon is known as the Pasteur effect.
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Note the blackening (left) of initially yellowish (right) starch. Several analytical methods are used for qualitative and quantitative determination of peroxides. A simple qualitative detection of peroxides is carried out with the iodine-starch reaction. Here peroxides, hydroperoxides or peracids oxidize the added potassium iodide into iodine, which reacts with starch producing a deep-blue color.
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This enzyme is termed "phagocyte NADPH oxidase" (PHOX). This enzyme oxidizes NADPH and reduces molecular oxygen to produce superoxide anions, a reactive oxygen species. Superoxide is then disproportionated into peroxide and molecular oxygen by superoxide dismutase. Finally, peroxide is used by myeloperoxidase to oxidize chloride ions into hypochlorite (the active component of bleach), which is toxic to bacteria.
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Many of these colours have faded or changed over time. Some light, lead-based pigments tend to oxidize into darker plattnerite when painted, as was the rule, on lime background (but not when painted on wood). Similarly, cinnabar red has occasionally turned into metacinnabar. In addition, organic pigments such as brazilin have faded because of exposure to sunlight.
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Beggiatoa can grow chemoorgano-heterotrophically by oxidizing organic compounds to carbon dioxide in the presence of oxygen, although high concentrations of oxygen can be a limiting factor. Organic compounds are also the carbon source for biosynthesis. Some species may oxidize hydrogen sulfide to elemental sulfur as a supplemental source of energy (facultatively litho- heterotroph). Produced sulfur is stored intracellularly.
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Caro's acid – peroxomonosulfuric acid (H2SO5) - converts cyanide to cyanate. Cyanate then hydrolyses to ammonium and carbonate ions. The Caro's acid process is able to achieve discharge levels of WAD below 50 mg/L, which is generally suitable for discharge to tailings. Hydrogen peroxide and basic chlorination can also be used to oxidize cyanide, although these approaches are less common.
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2-Iodoxybenzoic acid (IBX) is an organic compound used in organic synthesis as an oxidizing agent. This periodinane is especially suited to oxidize alcohols to aldehydes. IBX is prepared from 2-iodobenzoic acid, potassium bromate, and sulfuric acid. Frigerio and co-workers have also demonstrated, in 1999 that potassium bromate may be replaced by commercially available Oxone.
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The Sarett oxidation is an organic reaction that oxidizes primary and secondary alcohols to aldehydes and ketones, respectively, using chromium trioxide and pyridine. Unlike the similar Jones oxidation, the Sarett oxidation will not further oxidize primary alcohols to their carboxylic acid form, neither will it affect carbon-carbon double bonds.Margareta Avram (1983). "Chimie organica" p. 472.
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Hot, combustible gases (e.g. hydrogen and carbon-monoxide) may follow when they mix with oxygen in the surrounding air to produce the secondary flash, the brightest. The secondary flash does not usually occur with small arms.Moss G. M., Leeming D. W., Farrar C. L. Military Ballisitcs (1969) Nitrocellulose contains insufficient oxygen to completely oxidize its carbon and hydrogen.
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Repeated applications of wax had caused the pigments to oxidize and darken, and the frescoes to yellow, significantly altering their appearance. All the surface decorations of the villa, both mosaics and frescoes, had been conserved before, but in irregular ways. Some of the methods currently being employed have been used by decades of conservators at Pompeii.
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Water is more difficult to oxidize than its conjugate base hydroxide. Hydroxide is stabilized by coordination to metal cations. Some metal hydroxides, those featuring redox-active metal centers, can be oxidized to give metal oxo complexes. Attack of water on metal oxo centers represents one pathway for the formation of the O-O bond, leading to dioxygen.
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The optimum growth temperature for A. aeris is 30 °C, and can grow in the 25-35 °C range. The optimum pH is 3.5, and can grow in pH 2.0-6.0. A. aeris can oxidize iron and sulfur, as can Alicyclobacillus disulfidooxidans, A. ferrooxydans, and A. tolerans. Alicyclobacillus fodiniaquatilis was isolated from a different copper mine.
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Nanoscale iron particles are sub-micrometer particles of iron metal. They are highly reactive because of their large surface area. In the presence of oxygen and water, they rapidly oxidize to form free iron ions. They are widely used in medical and laboratory applications and have also been studied for remediation of industrial sites contaminated with chlorinated organic compounds.
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However, the stability of these doped materials is relatively low. In general, unaligned, unsubstituted PPV presents only moderate conductivity with doping, ranging from <<10-3 S/cm (I2 doped) to 100 S/cm (H2SO4-doped). Draw ratios of up to 10 are possible. Alkoxy- substituted PPVs are generally easier to oxidize than the parent PPV and hence have much higher conductivities.
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Using newer technology, it is now possible to coat yarns with pure 24 karat gold that are workable just like normal embroidery yarn. These yarns furthermore have a very well washing behaviour: they can be washed several times without losing metal. As there is no silver layer underneath the gold, the thread neither starts to oxidize as gold is inert.
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In organic synthesis OsO4 is widely used to oxidize alkenes to the vicinal diols, adding two hydroxyl groups at the same side (syn addition). See reaction and mechanism above. This reaction has been made both catalytic (Upjohn dihydroxylation) and asymmetric (Sharpless asymmetric dihydroxylation). Osmium(VIII) oxide is also used in catalytic amounts in the Sharpless oxyamination to give vicinal amino-alcohols.
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This reaction oxidizes NADPH to NADP+. Sorbitol dehydrogenase can then oxidize sorbitol to fructose, which produces NADH from NAD+. Hexokinase can return the molecule to the glycolysis pathway by phosphorylating fructose to form fructose-6-phosphate. However, in uncontrolled diabetics that have high blood glucose - more than the glycolysis pathway can handle - the reactions mass balance ultimately favors the production of sorbitol.
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Some of them, like the notion of zeppelins or the Statue of Liberty if we didn't let it oxidize or the Grand Central Hotel, we're not making up. Had the Hindenburg not blown up, zeppelins would be passenger air ships docking at the Empire State Building. That was the plan. We opened ourselves to the standard that it had to be possible.
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Among the heterotrophic SOB are included species of Beggiatoa that can grow mixotrophically, using sulfide to obtain energy (autotrophic metabolism) or to eliminate metabolically formed hydrogen peroxide in the absence of catalase (heterotrophic metabolism). Other organisms, such as the Bacteria Sphaerotilus natans and the yeast Alternaria are able to oxidize sulfide to elemental sulfur by means of the rDsr pathway.
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The economy of Tsuruta is heavily dependent on horticulture, especially for apples. Cold- hardy varieties of rice and many varieties of apples are grown in the town. Farmers in the area have developed a strain of apples that does not oxidize (turn brown) when cut. Aomori Bank, Michinoku Bank and Aoi Mori Shinkin Bank set Tsuruta Branch at the town.
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Caffeine dehydrogenase, commonly referred to in scientific literature as caffeine oxidase, () is an enzyme with the systematic name caffeine:ubiquinone oxidoreductase. The enzyme is most well known for its ability to directly oxidize caffeine, a type of methylxanthine, to trimethyluric acid. Caffeine dehydrogenase can be found in bacterium Pseudomonas sp. CBB1 and in several species within the genera Alcaligenes, Rhodococcus, and Klebsiella.
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Aqueous solutions of ferrates are pink when dilute, and deep red or purple at higher concentrations. The ferrate ion is a stronger oxidizing agent than permanganate, and will oxidize chromium(III) to dichromate, and ammonia to molecular nitrogen. The ferrate(VI) ion has two unpaired electrons, and is thus paramagnetic. It has a tetrahedral molecular geometry, isostructural with the chromate and permanganate ions.
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Fast scan cyclic voltammetry used to measure changing concentrations of dopamine. A carbon fiber electrode is used to quickly change the voltage to oxidize dopamine and reduce dopamine-O-quinone. The resulting alternating current is used to find the instantaneous concentration of dopamine in the extracellular fluid. Fast-scan cyclic voltammetry (FSCV) is cyclic voltammetry with a very high scan rate (up to ).
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Terra sigillata und griechische Schwarzrotmalerei. In: Berichte der deutschen keramischen Gesellschaft 32 (1942), S. 408–426. More References in Noble (1965). Since this final oxidizing phase was fired using lower temperatures, the glazed parts of the vase did not re-oxidize from black to red: their finer surface was melted (sintered) in the reducing phase, and now protected from oxygen.
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Coincidentally, high concentrations of hydrogen sulfide at deep-sea vents are produced by high temperature seawater-rock interactions . It is notable that microorganisms living in the deep, dark ocean oxidize sulfur compounds for chemolithoautotrophy; this process is microbially mediated . For example, sulfide quinone reductases (SQRs), found in all isolates of Sulfurimonas spp. aids in the oxidation of sulfur- and thiosulfate-containing compounds.
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An enzymatic biofuel cell is a specific type of fuel cell that uses enzymes as a catalyst to oxidize its fuel, rather than precious metals. Enzymatic biofuel cells, while currently confined to research facilities, are widely prized for the promise they hold in terms of their relatively inexpensive components and fuels, as well as a potential power source for bionic implants.
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Getting rid of the fission products reduced the gamma radiation by 90 percent. The precipitate was a plutonium-containing cake which was placed in another tank and dissolved in nitric acid. Sodium bismuthate or potassium permanganate was added to oxidize the plutonium. Plutonium would be carried by the bismuth phosphate in the tetravalent state but not in the hexavalent state.
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Bromine monochloride is used in analytical chemistry in determining low levels of mercury, to quantitatively oxidize mercury in the sample to Hg(II) state. Bromine monochloride is used as a biocide, specifically as an algaecide, fungicide, and disinfectant, in industrial recirculating cooling water systems. Addition of bromine monochloride is used in some types of Li-SO2 batteries to increase voltage and energy density.
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Commensalistic relationships between microorganisms include situations in which the waste product of one microorganism is a substrate for another species. One good example is nitrification-the oxidation of ammonium ion to nitrate. Nitrification occurs in two steps: first, bacteria such as Nitrosomonas spp. and certain crenarchaeotes oxidize ammonium to nitrite; and second, nitrite is oxidized to nitrate by Nitrobacter spp.
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In Taiwan, this plant is often grown under fruit trees in fruit orchards as a secondary crop. The plant is processed by harvesting all the aerial portions above the root. The portions are then partially dried and piled up in order to allow them to oxidize until they have darkened. After the oxidation, they are then thoroughly dried for sale.
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When oxygen is present, bacteria oxidize reduced sulfur to generate energy, potentially releasing bound arsenic. Redox reactions involving Fe also appear to be essential factors in the fate of arsenic in aquatic systems. The reduction of iron oxyhydroxides plays a key role in the release of arsenic to water. So arsenic can be enriched in water with elevated Fe concentrations.
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Paleosols, detrital grains, and redbeds are evidence of low-level oxygen. The paleosols older than 2.4 Ga have low iron concentrations that suggests anoxic weathering. Detrital grains older than 2.4 Ga also have material that only exists under low oxygen conditions. Redbeds are red-colored sandstones that are coated with hematite, which indicates that there was enough oxygen to oxidize iron.
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Ultraviolet A (UVA) radiation is in the wavelength range 320 to 400 nm. It is present more uniformly throughout the day, and throughout the year, than UVB. Most UVA is not blocked by the atmosphere's ozone layer. UVA causes the release of existing melanin from the melanocytes to combine with oxygen (oxidize) to create the actual tan color in the skin.
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Scale is precipitated impurities out of the water and then forms on heat transfer surfaces. This is a problem because scale does not transfer heat very well and causes the tubes to fail by getting too hot. Corrosion is caused by oxygen in the water. The oxygen causes the metal to oxidize which lowers the melting point of the metal.
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Reduced sulfur compounds, such as hydrogen sulfide, elemental sulfur, sulfite, thiosulfate, and various polythionates (e.g., tetrathionate), are used by various lithotrophic bacteria and are all oxidized by Acidithiobacillus. Sulfur oxidizers utilize enzymes such as Sulfide:quinone reductase, sulfur dioxygenase and sulfite oxidase to oxidize sulfur compounds to sulfate. Lithotrophs that can produce sugars through chemosynthesis make up the base of some food chains.
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Supercritical water oxidation uses supercritical water as a medium in which to oxidize hazardous waste, eliminating production of toxic combustion products that burning can produce. The waste product to be oxidised is dissolved in the supercritical water along with molecular oxygen (or an oxidising agent that gives up oxygen upon decomposition, e.g. hydrogen peroxide) at which point the oxidation reaction occurs.
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For example, nitrifying bacteria such as Nitrobacter oxidize nitrite to nitrate, which releases sufficient energy to pump protons and generate ATP, but not enough to produce NADH directly. As NADH is still needed for anabolic reactions, these bacteria use a nitrite oxidoreductase to produce enough proton-motive force to run part of the electron transport chain in reverse, generating NADH.
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M. acetivorans has been noted for its ability to metabolize carbon monoxide to form acetate and formate. It can also oxidize carbon monoxide into carbon dioxide. The carbon dioxide can then be converted into methane in a process which M. acetivorans uses to conserve energy. It has been suggested that this pathway may be similar to metabolic pathways used by primitive cells.
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Polyphenolic content can be quantified separation/isolation by volumetric titration. An oxidizing agent, permanganate, is used to oxidize known concentrations of a standard tannin solution, producing a standard curve. The tannin content of the unknown is then expressed as equivalents of the appropriate hydrolyzable or condensed tannin. Some methods for quantification of total polyphenol content are based on colorimetric measurements.
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Alkynes characteristically are capable of adding two equivalents of halogens and hydrogen halides. :RC≡CR′ + 2 Br2 → RCBr2CR′Br2 The addition of nonpolar E–H bonds across C≡C is general for silanes, boranes, and related hydrides. The hydroboration of alkynes gives vinylic boranes which oxidize to the corresponding aldehyde or ketone. In the thiol-yne reaction the substrate is a thiol.
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Oxidative decarboxylation then generates a ferryl intermediate coordinated to succinate, which serves to oxidize the bound primary substrate. Succinate may interfere with the enzymatic process by attaching to the Fe(II) center first, prohibiting the binding of 2-oxoglutarate. Thus, via enzymatic inhibition, increased succinate load can lead to changes in transcription factor activity and genome-wide alterations in histone and DNA methylation.
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The energy of an absorbed photon is transferred to electrons in the molecule and briefly changes their configuration (i.e., promotes the molecule from a ground state to an excited state). The excited state represents what is essentially a new molecule. Often excited state molecules are not kinetically stable in the presence of O2 or H2O and can spontaneously decompose (oxidize or hydrolyze).
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The Pinnick oxidation is an organic reaction by which aldehydes can be oxidized into their corresponding carboxylic acids using sodium chlorite (NaClO2) under mild acidic conditions. It was originally developed by Lindgren and Nilsson. The typical reaction conditions used today were developed by G. A. Kraus. H.W. Pinnick later demonstrated that these conditions could be applied to oxidize α,β-unsaturated aldehydes.
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In organic chemistry, dilute solutions of chromic acid can be used to oxidize primary or secondary alcohols to the corresponding aldehydes and ketones. Tertiary alcohol groups are unaffected. Because of the oxidation is signaled by a color change from orange to a blue-green, chromic acid is used as a qualitative analytical test for the presence of primary or secondary alcohols.
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Fluorine's chemistry is dominated by its strong tendency to gain an electron. It is the most electronegative element and elemental fluorine is a strong oxidant. The removal of an electron from a fluorine atom requires so much energy that no known reagents are known to oxidize fluorine to any positive oxidation state. Therefore, fluorine's only common oxidation state is −1.
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Copper cavities frequently oxidize, which increases their loss. Silver or gold plating prevents oxidation and reduces electrical losses in cavity walls. Even though gold is not quite as good a conductor as copper, it still prevents oxidation and the resulting deterioration of Q factor over time. However, because of its high cost, it is used only in the most demanding applications.
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Other genera, such as Gluconobacter, do not oxidize ethanol, as they do not have a full set of Krebs cycle enzymes. As these bacteria produce acid, they are usually acid-tolerant, growing well below pH 5.0, although the pH optimum for growth is 5.4-6.3. One species of Acetobacter, Acetobacter xylinum, is able to synthesize cellulose, something normally done only by plants.
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If the organic content of the sediment is too high the dissolved iron precipitates in the sediment and not in the carcass. Seawater sulfate ions diffusing toward animal carcasses enabled sulfate-reducing bacteria to oxidize the reactive organic matter of these remains, but the sulfide produced reacted promptly with the abundant Fe2+ ions of the pore water and pyrite precipitated right on the organic remains.
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Its diverse habitats, coupled to its ability to reduce a variety of metals, makes the genus critical for the cycling of minerals. For instance, under aerobic conditions, various species of Shewanellaare capable of oxidizing manganese. When conditions are changed, the same species can reduce the manganese oxide products. Hence, since Shewanella can both oxidize and reduce manganese, it is critical to the cycling of manganese.
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Sulfur can be removed from ores by roasting and washing. Roasting oxidizes sulfur to form sulfur dioxide which either escapes into the atmosphere or can be washed out. In warm climates it is possible to leave pyritic ore out in the rain. The combined action of rain, bacteria, and heat oxidize the sulfides to sulfuric acid and sulfates, which are water-soluble and leached out .
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The -SH groups on these residues act as strong nucleophiles, which can conjugate with a variety of molecules, including other glutathione molecules. Sulfur itself is able to exist in several different oxidation states; this redox flexibility combined with its strong nucleophilic properties allows glutathione to oxidize/readily pick up electrons from reactive oxygen species. Glutathione transferases play a key role in catalyzing such reactions.
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The overall process of glycolysis is: :Glucose + 2 NAD+ \+ 2 ADP + 2 Pi → 2 pyruvate + 2 NADH + 2 H+ \+ 2 ATP If glycolysis were to continue indefinitely, all of the NAD+ would be used up, and glycolysis would stop. To allow glycolysis to continue, organisms must be able to oxidize NADH back to NAD+. How this is performed depends on which external electron acceptor is available.
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The peroxide combines with residual tannins in the leather to oxidize proteins, creating ammonium sulfate and ammonium bisulfate. Red rot is also caused by problems in the tanning or in the bookbinding. In the tanning examples are: sulfuric acid residue, use of contaminated water and incomplete tanning. The bookbinding process can cause red rot when acids and bases are used when coloring the leather.
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The elements must remain covered with electrolyte; if they dry out, the negative plates oxidize and require a very long charge. The elements of a nickel iron (NiFe) cell The active material of the positive plates is a form of nickel hydrate. The tube retainers are made of thin steel ribbon, finely perforated and nickel-plated, about 4 in. long and 1/4 in.
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Various other substances begin to appear in significant amounts in combustion products when the flame temperature is above about . When excess air is used, nitrogen may oxidize to and, to a much lesser extent, to . forms by disproportionation of , and and form by disproportionation of . For example, when of propane is burned with of air (120% of the stoichiometric amount), the combustion products contain 3.3% .
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CuCl2, in the presence of oxygen, can also oxidize phenols. The major product can be directed to give either a quinone or a coupled product from oxidative dimerization. The latter process provides a high-yield route to 1,1-binaphthol: :Coupling of beta-naphthol using CuCl2. Such compounds are intermediates in the synthesis of BINAP and its derivatives Copper(II) chloride dihydrate promotes the hydrolysis of acetonides, i.e.
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From 1964 to 1972, 6061 aluminum wire and quick-wire receptacles were being installed in over two million homes, particularly tract homes. This wire was inferior, and the aluminum had tremendous expansion and contraction between power consumption and rest. Since power outlets were also constructed of dissimilar metals, the receptacles caused the aluminum to oxidize. Oxidization of aluminum creates aluminum oxide, which insulates rather than conducts.
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The spin states of these complexes are sensitive to the nature of the amine substituents. Iron tris(dithiocarbamate)s characteristically react with nitric oxide to give Fe(dtc)2NO. This efficient chemical trapping reaction provides a means to detect NO. Reflecting the strongly donating properties of dithiocarbamate ligands, iron tris(dithiocarbamate)s oxidize at relatively mild potentials to give isolable iron(IV) derivatives [Fe(S2CNR2)3]+.
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Many Fe2+ oxidizing microorganisms also oxidize sulfur and are thus obligate acidophiles that further acidify the environment by the production of H2SO4. This is due in part to the fact that at neutral pH Fe2+ is rapidly oxidized chemically in contact with the air. In these conditions there is not enough Fe2+ to allow significant growth. At low pH, however, Fe2+ is much more stable.
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The dioxide is a powerful oxidizer: it can oxidize hydrochloric and sulfuric acids. It does not reacts with alkaline solution, but reacts with solid alkalies to give hydroxyplumbates, or with basic oxides to give plumbates. Reaction of lead with sulfur or hydrogen sulfide yields lead sulfide. The solid has the NaCl-like structure (simple cubic), which it keeps up to the melting point, 1114 °C (2037 °F).
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Sulfurovum is a genus within the Epsilonproteobacteria which was first described in 2004 with the isolation and description of the type species Sulfurovum lithotrophicum from Okinawa trough hydrothermal sediments. Named for their ability to oxidize sulfur and their egg-like shape, cells are gram- negative, coccoid to short rods. Mesophilic chemolithoautotrophic growth occurs by oxidation of sulfur compounds coupled to the reduction of nitrate or molecular oxygen.
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Pseudomonas balearica is a Gram-negative, rod-shaped, nonfluorescent, motile, and denitrifying bacterium. It is an environmental bacterium that has been mostly isolated from polluted environments all over the world. Many of the isolates have demonstrated capabilities to degrade several compounds. Some of the strains are naphthalene degraders and one strain isolated in New Zealand has demonstrated the potential to oxidize inorganic sulfur compounds to tetrathionate.
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Protists grow in a wide variety of moist habitats and a majority of them are free-living organisms. In these moist environments, plankton and terrestrial forms can also be found. Protists are chemoorganotrophic [organisms which oxidize the chemical bonds in organic compounds as their energy source] and are responsible for recycling nitrogen and phosphorus. Parasites also are responsible for causing disease in humans and domesticated animals.
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Methylchloroisothiazolinone, also referred to as MCI, is a preservative with antibacterial and antifungal effects within the group of isothiazolinones. These compounds have an active sulphur moiety that is able to oxidize thiol- containing residues, thereby effectively killing most aerobic and anaerobic bacteria. Methylchloroisothiazolinone is effective against gram-positive and gram-negative bacteria, yeast, and fungi. Methylchloroisothiazolinone is found in many water-based personal care products and cosmetics.
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Also in contrast to most other DIRB, G. fermentans cannot utilize elemental sulfur as an electron acceptor, a characteristic it shares with DIRB of the genera Geobacter. Geothrix fermentans can also employ fermentation, as its name implies, to oxidize substrates for energy production. This organism exhibited an ability to grow fermentatively on organic acids such as fumarate and citrate yielding acetate and succinate as fermentation products.
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Sulfate reduction pathway Methanogenesis is the process by which methanogen microbes form methane (CH4). OMZs are know contain the largest amount of methane in the open ocean. Methanogens can also oxidize methane as they have the genes to do so, however this requires oxygen which they obtain from photosynthetic organisms in the upper anoxic zone. Ciliates may also aid methanogens through symbiosis to help facilitate methanogenesis.
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An important problem of the industrial revolution was the preservation of flour. Transportation distances and a relatively slow distribution system collided with natural shelf life. The reason for the limited shelf life is the fatty acids of the germ, which react from the moment they are exposed to oxygen. This occurs when grain is milled; the fatty acids oxidize and flour starts to become rancid.
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Adherence of OGG1 to the 5mCp-8-OHdG site recruits TET1, allowing TET1 to oxidize the 5mC adjacent to 8-OHdG, as shown in the first figure in this section. This initiates the demethylation pathway shown in the second figure in this section. Altered protein expression in neurons, controlled by ROS-dependent demethylation of CpG sites in gene promoters within neuron DNA, is central to memory formation.
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In addition, any nonstoichiometry in the Fe(III)–Fe(II) range is titrated directly with no additives, any nonstoichiometry below Fe2+ will reduce 1 M FeCl3 whereas any nonstoichiometry above Fe3+ will oxidize Mohr's salt. In the second- and third-row transition metals, only the early elements would be suitable for the titration, and the limiting oxidation states are Zr4+, Nb5+, Mo4+, Hf4+, Ta5+, and W6+.
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Songluo-style green tea became popular, and the new production method spread to other regions. In the 16th century, Wuyi tea makers invited monks from Songluo to teach their techniques to them. Eventually they discovered that by allowing the tea to partially oxidize before firing, they could produce a darker, fragrant type of tea which came to be known as oolong (wūlóng, "black dragon") tea.
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Barium manganate oxidizes a number of functional groups efficiently and selectively: alcohols to carbonyls, diols to lactones, thiols to disulfides, aromatic amines to azo-compounds, hydroquinone to p-benzoquinone, benzylamine to benzaldehyde, etc..Procter.G.; Ley, S. V.; Castle, G.H. (2004), "Barium Manganate", in Paquette,L., Encyclopedia of Reagents for Organic Synthesis, New York:Wiley, . It does not oxidize saturated hydrocarbons, alkenes, unsaturated ketones, and tertiary amines.
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Microbes derive energy by oxidizing or reducing elements. Different microbial species utilize different chemical species of an element in their metabolic processes. For example, some microbe species oxidize sulfide to sulfate and another species will reduce sulfate to elemental sulfur. As a result, a web of chemical pathways mediated by different microbial species transform elements such as carbon, sulfur, nitrogen, and hydrogen, from one species to another.
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Since ammonia is a stronger ligand in the spectrochemical series than water, metal ammine complexes are stabilized relative to the corresponding aquo complexes. For similar reasons, metal ammine complexes are less strongly oxidizing than are the corresponding aquo complexes. The latter property is illustrated by the stability of [Co(NH3)6]3+ in aqueous solution and the nonexistence of [Co(H2O)6]3+ (which would oxidize water).
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It is suspected that this difference in isoenzyme is due to the predominant pathway the lactate will take - in liver it is more likely to be gluconeogenesis, whereas in the myocardium it is more likely to be oxidation. Despite these differences, it is thought that the redox state of the mitochondria dictates the ability of the tissues to oxidize lactate, not the particular LDH isoform.
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Once the sulfates are depleted, methane formation takes over. The depth of the chemical zones depends on the rate that organic matter is deposited. Where it is rapid, oxygen is taken up rapidly as organic matter is consumed; where slow, oxygen can persist much deeper because of the lack of nutrients to oxidize. Ocean sediment habitats can be divided into subduction zones, abyssal plains, and passive margins.
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Aldehyde dehydrogenase, dimeric NADP-preferring is an enzyme that in humans is encoded by the ALDH3A1 gene. Aldehyde dehydrogenases oxidize various aldehydes to the corresponding acids. They are involved in the detoxification of alcohol-derived acetaldehyde and in the metabolism of corticosteroids, biogenic amines, neurotransmitters, and lipid peroxidation. The enzyme encoded by this gene forms a cytoplasmic homodimer that preferentially oxidizes aromatic aldehyde substrates.
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EPA/540/1-86/001 The figure below gives an indication of possible degradation pathways when HCCPD is released into the environment. Light, water and oxygen can cause a double bond to oxidize to give a ketone structure, which can then undergo a ring-opening and form pentachlorodienoic acid, which forms two butadiene species with the release of carbon dioxide. However, this is only a minor pathway.
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Indian Journal of Microbiology 53, 377–384 (2013). Besides food industry, some acetic acid bacteria are used as biocatalysts for the industrial production of compounds. They are used as the important biocatalysts for the development of eco- friendly fermentation processes as an alternative to the chemical synthesis. Some genera, such as Acetobacter, can oxidize ethanol to carbon dioxide and water using Krebs cycle enzymes.
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Because of the simplicity of sample handling, TV–GC–MS is still considered the standard method for organic detection on future Mars missions, so Navarro-González suggests that the design of future organic instruments for Mars should include other methods of detection. After the discovery of perchlorates on Mars by the Phoenix lander, practically the same team of Navarro-González published a paper arguing that the Viking GCMS results were compromised by the presence of perchlorates. A 2011 astrobiology textbook notes that "while perchlorate is too poor an oxidizer to reproduce the LR results (under the conditions of that experiment perchlorate does not oxidize organics), it does oxidize, and thus destroy, organics at the higher temperatures used in the Viking GCMS experiment." Biemann has written a commentary critical of this Navarro-González paper as well, to which the latter have replied; the exchange was published in December 2011.
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" Experiments conducted in 2008 by the Phoenix lander discovered the presence of perchlorate in Martian soil. The 2011 astrobiology textbook discusses the importance of this finding with respect to the results obtained by Viking as "while perchlorate is too poor an oxidizer to reproduce the LR results (under the conditions of that experiment perchlorate does not oxidize organics), it does oxidize, and thus destroy, organics at the higher temperatures used in the Viking GCMS experiment. NASA astrobiologist Chris McKay has estimated, in fact, that if Phoenix-like levels of perchlorates were present in the Viking samples, the organic content of the Martian soil could have been as high as 0.1% and still would have produced the (false) negative result that the GCMS returned. Thus, while conventional wisdom regarding the Viking biology experiments still points to "no evidence of life", recent years have seen at least a small shift toward "inconclusive evidence".
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Cardiac muscle is slightly different from skeletal muscle. At rest, they prefer to utilize fatty acids as their main energy source. As activity increases and it begins to pump faster, the cardiac muscles begin to oxidize glucose at a higher rate. An analysis of mRNA levels of GLUT1 and GLUT4 in cardiac muscles show that GLUT1 plays a larger role in cardiac muscles than it does in skeletal muscles.
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General overview of microbial biodegradation of petroleum oil by microbial communities. Some microorganisms, such as A. borkumensis, are able to use hydrocarbons as their source for carbon in metabolism. They are able to oxidize the environmentally harmful hydrocarbons while producing harmless products, following the general equation CnHn \+ O2 → H2O + CO2. In the figure, carbon is represented as yellow circles, oxygen as pink circles, and hydrogen as blue circles.
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N. cinerea can produce acid from glucose like N. gonorrhoeae, but it will then oxidize the acid to carbon dioxide. Although it can break down glucose, it is unable to use glucose or other carbohydrates for energy, making it asaccharolytic. In addition, N. cinerea will react in coagglutination serologic tests and, like N. gonorrhoeae, it produces the enzyme hydroxyprolylaminopeptidase.N. cinerea does not reduce nitrate, but it does reduce nitrite.
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Disulfide bonds are usually formed from the oxidation of sulfhydryl (−SH) groups, especially in biological contexts. The transformation is depicted as follows: :2 RSH RS−SR + 2 H+ \+ 2 e− A variety of oxidants participate in this reaction including oxygen and hydrogen peroxide. Such reactions are thought to proceed via sulfenic acid intermediates. In the laboratory, iodine in the presence of base is commonly employed to oxidize thiols to disulfides.
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Improperly prepared tissue samples may give false positives. In research, this reaction is used to stain cells that were prepared with hydrogen peroxidase enzyme, following common immunocytochemistry protocols. Relevant to Alzheimer's disease, Aβ protein amyloid plaques are targeted by a primary antibody, and subsequently by a secondary antibody, which is conjugated with a peroxidase enzyme. This will bind DAB as a substrate and oxidize it, producing an easily observable brown color.
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The tiny bubbles within the chocolate form via aerating the molten chocolate with gas, typically carbon dioxide or nitrogen, while at a high pressure, which causes microscopic gas bubbles to form within the liquid. The liquid is then lowered to atmospheric pressure as it cools, causing the gas pockets to expand and become trapped in the chocolate. Air is not used to make the bubbles as this would oxidize the chocolate.
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Commercial systems typically use a bubble column reactor, where air is bubbled through a vertical column that is liquid full of the hot and pressurized wastewater. Fresh wastewater enters the bottom of the column and oxidized wastewater exits the top. The heat released during the oxidation is used to maintain the operating temperature. WAO is a liquid phase reaction using dissolved oxygen in water to oxidize wastewater contaminants.
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Methylotrophs such as Methylophilus oxidize compounds such as methanol into carbon dioxide and are key to the carbon cycle. Gallionella and Ferriphaselus oxidise ferric iron (Fe3+) ions into ferric hydroxide (Fe(OH)3) during autotrophic growth, and thus have roles in the carbon cycle and the iron cycle. As such, the Nitrosomonadales are critical to biogeochemical cycling of the elements and many species have key roles in principal biochemical processes.
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Rimfire bullets are generally either plain lead with a wax coating (for standard-velocity loads) or plated with copper or gilding metal (for high-velocity or hyper-velocity loads). The thin copper layer on plated bullet functions as a lubricant reducing friction between the bullet and the barrel, thus reducing barrel wear. Plating also prevents oxidation of the lead bullet. Lead tends to oxidize if stored for long periods.
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One theory of bottom-up control lies with differential soil chemistry between vegetated and die-off areas. Drought-associated changes in soil chemistry have been proposed to be associated with areas of die-off. Droughts are often associated with increased salinity and acidity stress - soils oxidize under freshwater or tidal moisture limitation, leading to increased acidity. Hypersalinity has been linked to reduced S. alterniflora survival (Brown et al. 2005).
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Adherence of OGG1 to the 5mCp-8-OHdG site recruits TET1, allowing TET1 to oxidize the 5mC adjacent to 8-OHdG, as shown in the first figure in this section. This initiates the demethylation pathway shown in the second figure in this section. Altered protein expression in neurons, controlled by 8-oxo-dG-dependent demethylation of CpG sites in gene promoters within neuron DNA, is central to memory formation.
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2009, volume 6, pp. 133–150. Some anaerobic bacteria and archaea use the Wood-Ljungdahl pathway in reverse to break down acetate. For example, some methanogens break down acetate to a methyl group and carbon monoxide, and then reduce the methyl group to methane while oxidizing the carbon monoxide to carbon dioxide. Sulfate reducing bacteria, meanwhile, oxidize acetate completely to CO2 and H2 coupled with the reduction of sulfate to sulfide.
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Acetobacter is a genus of acetic acid bacteria. Acetic acid bacteria are characterized by the ability to convert ethanol to acetic acid in the presence of oxygen. Of these, the genus Acetobacter is distinguished by the ability to oxidize lactate and acetate into carbon dioxide and water. Bacteria of the genus Acetobacter have been isolated from industrial vinegar fermentation processes and are frequently used as fermentation starter cultures.
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Aerobic organisms require oxygen to survive and as oxygen becomes limited in OMZs bacteria begin to use other molecules to oxidize organic matter such as nitrate. Aerobic respiration in OMZs helps remineralize organic matter and is a major source of ammonium for most of the upper oxygen minimal zones. It was also found that bacteria from OMZs use a 1/6 of the oxygen for respiration compared bacteria in normal waters.
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Methanohalophilus mahii is capable of utilizing several metabolic pathways to either reduce or oxidize methyl groups, creating either methane or carbon dioxide in the process. In the reductive methylotrophic methanogenic pathway, Methanohalophilus mahii can eventually reduce a methyl group to a methane, which is released. In the oxidative methylotrophic pathway, the methyl group is instead oxidized to carbon dioxide and released. This process directly contributes to carbon mineralization in marine ecosystems.
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With 46% arsenic content, arsenopyrite, along with orpiment, is a principal ore of arsenic. When deposits of arsenopyrite become exposed to the atmosphere, the mineral will slowly oxidize, converting the arsenopyrite into an iron arsenate, a relatively stable compound. Arsenopyrite is generally an acid consuming sulfide mineral unlike iron pyrite which can lead to acid mine drainage. The crystal habit, hardness, density, and garlic odor when struck are diagnostic.
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Commensalism is very common in microbial world, literally meaning "eating from the same table". Metabolic products of one microbial population are used by another microbial population without either gain or harm for the first population. There are many "pairs "of microbial species that perform either oxidation or reduction reaction to the same chemical equation. For example, methanogens produce methane by reducing CO2 to CH4, while methanotrophs oxidize methane back to CO2.
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On the MC (cassette) format of the single, the track "Oxidize", was made available on CD for the first time in 2004 via the b-sides album Picture of Perfect Youth. The track was a critical success, and was named Melody Maker's "Single Of The Week".The Singles DVD- Sleeve Notes feature The song was about a relationship ending, and the person waiting for his partner to return to him.
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S. solfataricus is able to oxidize sulfur according to metabolic strategy, one of the products of these reactions is H+ and, consequentially, it results in a slowly acidification of surrounding area. Soil acidification increase in place where there are emissions of pollutants from industrial activity, and this process reduce the number of heterotrophic bacterial involved to decomposition, which are foundamental to recycling organic matter and ultimately to fertilizing soil.
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The first report of this phenomenon was the degradation of ethane by the species Pseudomonas methanica. These bacteria degrade their growth-substrate methane with the enzyme methane monooxygenase (MMO). MMO was discovered to be capable of degrading ethane and propane, although the bacteria were unable to use these compounds as energy and carbon sources to grow. Another example is Mycobacterium vaccae, which uses an alkane monooxygenase enzyme to oxidize propane.
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Molecular structure of the Sarett/Collins reagent The reaction is named after the American chemist Lewis Hastings Sarett (1917–1999). The first description of its use appears in a 1953 article co-authored by Sarett that relates to the synthesis of adrenal steroids. The paper proposes the use of the pyridine chromium complex CrO3-2C5H5N to oxidize primary and secondary alcohols. The complex would later become known as the "Sarett Reagent".
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It went through several revisions. The E/I connects to the CPU/keyboard with a 6-inch ribbon cable which is unshielded against RF interference and its card edge connector tends to oxidize due to its base metal contacts. This demands periodic cleaning with a pencil eraser in order to avoid spontaneous reboots, which contributes to its "Trash-80" sobriquet. Aftermarket connectors plated with gold solves this problem permanently.
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Sulfolobus metallicus could potentially be utilized to eliminate reduced sulfur compounds, such as hydrogen sulphide (H2S), near urban areas that cause disturbing odours. Many industries have H2S gas emissions that present many environmental problems as well as a foul odour. S. metalllicus has shown that it can oxidize these compounds and potentially eliminate many of those emissions. Many of these industrial emissions occur at high temperatures and low concentrations.
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The reduction of Fe(III) is seen to oxidize sulfur (from HS to SO), which is a central process in marine sediments. Many of the first metalloproteins consisted of iron-sulphur complexes formed during photosynthesis. Iron is the main redox metal in biological systems. In proteins, it is found in a variety of sites and cofactors, including, for instance, haem groups, Fe–O–Fe sites, and iron–sulfur clusters.
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A plasma containing oxygen is used to oxidize ("ash") photoresist and facilitate its removal. Ion milling, or sputter etching, uses lower pressures, often as low as 10−4 Torr (10 mPa). It bombards the wafer with energetic ions of noble gases, often Ar+, which knock atoms from the substrate by transferring momentum. Because the etching is performed by ions, which approach the wafer approximately from one direction, this process is highly anisotropic.
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AOR is found in hyperthermophillic archaea, Pyrococcus furiosus. The archaeons Pyrococcus ES-4 strain and Thermococcus ES-1 strain differ by their substrate specificity: AFOs show a broader size range of its aldehyde substrates. Its primary role is to oxidize aldehyde coming derived from the metabolism of amino acids and glucoses. Aldehyde Ferredoxin Oxidoreductase is a member of an AOR family, which includes glyceraldehyde-3-phosphate ferredoxin oxidoreductase (GAPOR) and Formaldehyde Ferredoxin Oxidoreductase.
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The arc may also be hot enough to evaporate metal from the contact surface. The high temperatures can also cause the contact metals to more rapidly oxidize and corrode. Contacts reach end of life for one of two reasons. Either the contacts fail to break because they are stuck (welded) closed, or the contacts fail to make (high resistance) because of contact corrosion or because excessive material is lost from one or both contacts.
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North Antelope Rochelle open-pit coal mine, in Wyoming, United States. After mining finishes, the mine area may undergo land rehabilitation. Waste dumps are contoured to flatten them out, to further stabilize them. If the ore contains sulfides it is usually covered with a layer of clay to prevent access of rain and oxygen from the air, which can oxidize the sulfides to produce sulfuric acid, a phenomenon known as acid mine drainage.
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The RF generator is switched on and the metallic chips quickly start heating up and readily oxidize into more zirconia. Consequently, the surrounding powder heats up by thermal conduction and begins melting, which in turn becomes electroconductive and thus it begins to heat up via the RF generator as well. This continues until the entire product is molten. Due to the cooling system surrounding the crucible, a thin shell of sintered solid material is formed.
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Shaking the flask causes oxygen present in the head space air to dissolve in the solution and oxidize the leuco-methylene blue back to its colored form again. Another variation uses methylene blue in water, glucose, and caustic soda (NaOH). In the past, it was thought that the reaction occurred by the oxidation of an aldehyde group to a carboxylic acid under alkaline conditions. For instance, glucose would be oxidized to gluconate by oxygen.
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Almost any conductive wire can be used for heating, but most metals conduct electricity with great efficiency, requiring them to be formed into very thin and delicate wires to create enough resistance to generate heat. When heated in air, most metals then oxidize quickly, become brittle and break. Nichrome wire, when heated to red-hot temperatures, develops an outer layer of chromium oxide,"Advanced Topic: Oxidation Resistant Materials" (PDF). Sciences Education Foundation.
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Carbon dioxide is a by-product of the fermentation of sugar in the brewing of beer, whisky and other alcoholic beverages and in the production of bioethanol. Yeast metabolizes sugar to produce and ethanol, also known as alcohol, as follows: : → 2 + 2 All aerobic organisms produce when they oxidize carbohydrates, fatty acids, and proteins. The large number of reactions involved are exceedingly complex and not described easily. Refer to (cellular respiration, anaerobic respiration and photosynthesis).
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This agar preparation facilitates the growth of Neisseria species while inhibiting the growth of contaminating bacteria and fungi. Martin Lewis and New York City agar are other types of selective chocolate agar commonly used for Neisseria growth. N. gonorrhoeae is oxidase positive (possessing cytochrome c oxidase) and catalase positive (able to convert hydrogen peroxide to oxygen). When incubated with the carbohydrates lactose, maltose, sucrose, and glucose, N. gonorrhoeae will oxidize only the glucose.
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Other Alicyclobacillus species that are able to oxidize iron include A. disulfidooxidans, A. pohliae, and A. tolerans. The optimum growth temperature for A. ferrooxydans is 28 °C, and can grow in the 17-40 °C range. The optimum pH is 3.0, and can grow in pH 2.0-6.0. A. ferrooxydans was found to be able to produce high amounts of biosurfactants that interacted with pyrite, and was able to change surface properties of pyrite.
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This compares to modern values less than 1 to 4. This bark, which must have been used as support as well as protection, probably had 38% to 58% lignin. Lignin is insoluble, too large to pass through cell walls, too heterogeneous for specific enzymes, and toxic, so that few organisms other than Basidiomycetes fungi can degrade it. To oxidize it requires an atmosphere of greater than 5% oxygen, or compounds such as peroxides.
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Other types of passive treatment systems include various limestone treatment configurations, ranging from limestone ponds to open limestone channels in which water flows down a steep slope with limestone riprap. These systems oxidize and precipitate metals and add alkalinity to the water. Another passive treatment system uses lime dispensing technology to neutralize acidity and precipitate metals in a settling pond. These units do not require power or hazardous chemicals and are inexpensive.
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A hydrogen sulfide sensor or H2S sensor is a gas sensor for the measurement of hydrogen sulfide.H2S sensors In a laboratory, hydrogen sulfide is prepared by the action of dilute sulfuric acid on iron sulfide. : FeS(s)+H2SO4(aq) → FeSO4(aq) + H2S(g) Concentrated sulfuric acid and nitric acid cannot be used for this process as they oxidize hydrogen sulfide to sulfur. A Woulf's bottle is fitted with a thistle funnel and a delivery tube.
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The propellant particle size distribution has a profound impact on APCP rocket motor performance. Smaller AP and Al particles lead to higher combustion efficiency but also lead to increased linear burn rate. The burn rate is heavily dependent on mean AP particle size as the AP absorbs heat to decompose into a gas before it can oxidize the fuel components. This process may be a rate-limiting step in the overall combustion rate of APCP.
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H2O2 is important in aquatic environments because it can oxidize dissolved organic matter and affect the redox chemistry of iron, copper, and manganese. Since hydrogen peroxide, as an uncharged molecule, diffuses easily across biological membranes it can directly damage cellular constituents (DNA and enzymes) by reacting with them and deactivating their functions. In addition, hydrogen peroxide reduces to the hydroxyl radical, the most reactive radical and the one with the greatest possibility for damage.
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Gasification :CH4 \+ H2O → CO + 3 H2 In a second stage, additional hydrogen is generated through the lower-temperature, exothermic, water gas shift reaction, performed at about 360 °C: :CO + H2O → CO2 \+ H2 Essentially, the oxygen (O) atom is stripped from the additional water (steam) to oxidize CO to CO2. This oxidation also provides energy to maintain the reaction. Additional heat required to drive the process is generally supplied by burning some portion of the methane.
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Lilial is commonly produced and sold as a racemic mixture; however, testing has indicated that the different enantiomers of the compound do not contribute equally to its odor. The (R)-enantiomer has a strong floral odor, reminiscent of cyclamen or lily of the valley; whereas the (S)-enantiomer possesses no strong odor. :(R)-Lilial (top) and (S)-lilial Like most aldehydes, lilial is not long term stable and tends to slowly oxidize on storage.
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A presumed blood sample is first collected with a swab. A drop of phenolphthalein reagent is added to the sample, and after a few seconds, a drop of hydrogen peroxide is applied to the swab. If the swab turns pink rapidly, it is said to test presumptive positive for blood. Waiting for periods over 30 seconds will result in most swabs turning pink naturally as they oxidize on their own in the air.
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The Dow process is the electrolytic method of bromine extraction from brine, and was Herbert Henry Dow's second revolutionary process for generating bromine commercially. This process was patented in 1891. In the original invention, bromide-containing brines are treated with sulfuric acid and bleaching powder to oxidize bromide to bromine, which remains dissolved in the water. The aqueous solution is dripped onto burlap, and air is blown through causing bromine to volatilize.
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Fenton's reagent is a solution of hydrogen peroxide (H2O2) with ferrous iron (typically iron(II) sulfate, FeSO4) as a catalyst that is used to oxidize contaminants or waste waters. Fenton's reagent can be used to destroy organic compounds such as trichloroethylene (TCE) and tetrachloroethylene (perchloroethylene, PCE). It was developed in the 1890s by Henry John Horstman Fenton as an analytical reagent.Hayyan M., Hashim M.A., AlNashef I.M., Superoxide ion: Generation and chemical implications. Chem. Rev.
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The wire train bus has been designed for international passenger trains with variable composition, consisting of up to 22 vehicles. The medium consists of a duplicated shielded twisted pair cable, which runs in the UIC cables between the vehicles. The connector between the vehicles is the 18-pole UIC connector. Since connectors are exposed and can oxidize, a current pulse is applied at connection establishment to evaporate the oxide layer, called fritting.
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With electrophiles, electrophilic substitution takes place where pyridine expresses aromatic properties. With nucleophiles, pyridine reacts at positions 2 and 4 and thus behaves similar to imines and carbonyls. The reaction with many Lewis acids results in the addition to the nitrogen atom of pyridine, which is similar to the reactivity of tertiary amines. The ability of pyridine and its derivatives to oxidize, forming amine oxides (N-oxides), is also a feature of tertiary amines.
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Mutations in this gene cause pyridoxine- dependent epilepsy, which involves a combination of various seizure types that do not respond to standard anticonvulsants, but are treatable via administration of pyridoxine hydrochloride. These pyridoxine-dependent seizures have been linked to the failure to oxidize α-AASA in patients due to mutated antiquitin. Additionally, antiquitin is implicated in other diseases, including cancer, diabetes, osteoporosis, premature ovarian failure and Huntington's disease, though the exact mechanisms remain unclear.
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In many ways, niobium is similar to tantalum and zirconium. It reacts with most nonmetals at high temperatures; with fluorine at room temperature; with chlorine at 150 °C and hydrogen at 200 °C; and with nitrogen at 400 °C, with products that are frequently interstitial and nonstoichiometric. The metal begins to oxidize in air at 200 °C. It resists corrosion by fused alkalis and by acids, including aqua regia, hydrochloric, sulfuric, nitric and phosphoric acids.
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Solder paste must be refrigerated when transported and stored in an airtight container at a temperature between 0-10 °C. It should be warmed to room temperature for use. Recently, new solder pastes have been introduced that remain stable at 26.5 °C for one year and at 40 °C for one month. Exposure of the solder particles, in their raw powder form, to air causes them to oxidize, so exposure should be minimized.
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The bacteria oxidize the reduced flavin mononucleotide to oxidized FMN and transfer it through free fusion to generate light. In humans, flavin reductase often catalyzes an NADPH dependent reduction of flavin mononucleotide which occurs in methemoglobin in erythrocytes and the liver. It has also been suggested that flavin reductases play a role in the production of hydrogen peroxide. This would be biologically helpful as H2O2 assists the body in maintaining homeostatic microbiota.
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Both additives are able to oxidize the ruthenium hydrides which may explain their behavior. frameless Another common problem associated with RCM is the risk of catalyst degradation due to the high dilution required for some cyclizations. High dilution is also a limiting factor in industrial applications due to the large amount of waste generated from large-scale reactions at a low concentration. Efforts have been made to increase reaction concentration without compromising selectivity.
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Thiobacteria such as Acidithiobacillus ferrooxidans have become essential to industrial bioleaching applications, as the microorganisms are able to oxidize iron and sulfur from iron-sulfur minerals as energy sources, supporting their own autotrophic growth while producing ferric iron and sulfuric acid. Thus, bacteria have been isolated from mineral deposits and used in the treatment of refractory gold and iron ores and detoxification of industrial waste products, sewage, and soils contaminated with heavy metals.
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Alkaline hydrogen peroxide is the most commonly used bleaching agent for mechanical pulp. The amount of base such as sodium hydroxide is less than that used in bleaching chemical pulps and the temperatures are lower. These conditions allow alkaline peroxide to selectively oxidize non-aromatic conjugated groups responsible for absorbing visible light. The decomposition of hydrogen peroxide is catalyzed by transition metals, and iron, manganese and copper are of particular importance in pulp bleaching.
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When there is a homozygous mutation it causes a uroporphyrinogen III synthase and uroporphyrinogen cosynthase defect. When the enzyme uroporphyrinogen III synthase is reacting normally it results in the making of isomer III porphyrinogen, which is what is used to form heme. When isomer III porphyrinogen is not produced because of a poor production of uroporphyrinogen III synthase then isomer I porphyrinogen is made which will oxidize and give a reddish tint skin.
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Some species have the ability of chemolitho-autotrophic growth by means of sulfide oxidation for energy and with carbon dioxide as a source of carbon for biosynthesis. In this metabolism internal stored nitrate is the electron acceptor and reduced to ammonia. ::Sulfide oxidation: 2H2S + O2 → 2S + 2H2O Marine autotrophic Beggiatoa species are able to oxidize intracellular sulfur to sulfate. A frequently occurring mechanism when oxygen is lacking is reduction of elemental sulfur.
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Biosynthesis of oxylipins is initiated by dioxygenases or monooxygenases; however also non-enzymatic autoxidative processes contribute to oxylipin formation (phytoprostanes, isoprostanes). Dioxygenases include lipoxygenases (plants, animals, fungi), heme-dependent fatty acid oxygenases (plants, fungi), and cyclooxygenases (animals). Fatty acid hydroperoxides or endoperoxides are formed by action of these enzymes. Monooxygenases involved in oxylipin biosynthesis are members of the cytochrome P450 superfamily and can oxidize double bonds with epoxide formation or saturated carbons forming alcohols.
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Erbium(III)chloride in sunlight, showing some pink fluorescence of Er+3 from natural ultraviolet. A trivalent element, pure erbium metal is malleable (or easily shaped), soft yet stable in air, and does not oxidize as quickly as some other rare-earth metals. Its salts are rose- colored, and the element has characteristic sharp absorption spectra bands in visible light, ultraviolet, and near infrared. Otherwise it looks much like the other rare earths.
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The host K. polythalamius can be found in the Philippines. Its habitat is woody organic-rich marine sediment. The giant shipworm has a symbiotic relationship with T. teredinicola which in exchange for housing can oxidize inorganic sulfur compounds to generate energy that is used to fix inorganic carbon and nitrogen into food for the shipworm host.Marvin A. Altamia, J. Reuben Shipway, Gisela P. Concepcion, Margo G. Haygood, and Daniel L. Distel. (2019).
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This gene is one of three related genes that have 2-hydroxyacid oxidase activity yet differ in encoded protein amino acid sequence, tissue expression and substrate preference. Subcellular location of the encoded protein is the peroxisome. Specifically, this gene is expressed primarily in liver and pancreas and the encoded protein is most active on glycolate, a two-carbon substrate. Glycolate oxidase oxidizes glycolic acid to glyoxylate, and can also oxidize glyoxylate into oxalate.
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However, an effort led by generous supporters arose and kept the museum in the Golden Gate Park. The designers were sensitive to the appearance of the building in its natural setting. Walter Hood, a landscape architect based in Oakland, designed the museum's new gardens. The entire exterior is clad in of copper, which is expected to eventually oxidize and take on a greenish tone and a distinct texture to echo the nearby eucalyptus trees.
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Conductive polymers can be doped by adding chemical reactants to oxidize, or sometimes reduce, the system so that electrons are pushed into the conducting orbitals within the already potentially conducting system. There are two primary methods of doping a conductive polymer, both of which use an oxidation-reduction (i.e., redox) process. # Chemical doping involves exposing a polymer such as melanin, typically a thin film, to an oxidant such as iodine or bromine.
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Starting in 2010, flotation analysis was used to get a better understanding of organic materials, including pollen and foodstuffs. In addition, black carbon (BC) analysis was used to gain a deeper understanding of the history of fire at Ifri Oudadane. This method entails using an acid to oxidize the carbon into benzene polycarboxylic acids. A variety of information can be gathered from this method, including the composition of fires and at which temperature they burned.
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In biotechnology, S. kiliense, which use to belong to the genus Cephalosporium produces cephalosporin C, an antibiotic similar to that of penicillin. Moreover, since S. kiliense use to belong to the genus Acremonium, it was noted that species from this genus can degrade polysaccharides, pectin, Carboxymethyl cellulose, xylans, and with S. kiliense mainly degrading starch. Furthermore, the fungus is also known to oxidize manganese in the soil and produce alkaline proteases and amylases.
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This usually only occurs once the steel has been in use for varying degrees of time. Some physical components of the steelmaking process itself, such as the electric arc furnace, may also wear down and oxidize. This issue is typically dealt with by the use of refractory metals, which are resistant to change. If steel is not properly deoxidized, it will have reduced various properties such as tensile strength, ductility, toughness, weldability, polishability, and machinability.
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This degrades organic compounds, including those that are ordinarily robust, such as aromatic or halogenated compounds. It can also oxidize sulfur based compounds present in the waste; which is beneficial as it generally reduces their odour. Hydrogen peroxide may be used for the sterilization of various surfaces, including surgical tools, and may be deployed as a vapour (VHP) for room sterilization. H2O2 demonstrates broad- spectrum efficacy against viruses, bacteria, yeasts, and bacterial spores.
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For example, potassium superoxide () is an orange-yellow solid formed when potassium reacts with oxygen. Hydrogen peroxide () can be produced by passing a volume of 96% to 98% hydrogen and 2 to 4% oxygen through an electric discharge. A more commercially-viable method is to allow autoxidation of an organic intermediate, 2-ethylanthrahydroquinone dissolved in an organic solvent, to oxidize to and 2-ethylanthraquinone. The 2-ethylanthraquinone is then reduced and recycled back into the process.
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In yeasts, galactose oxidase catalyzes the following reaction: :D-galactose + O2 \rightleftharpoons D-galacto-hexodialdose + H2O2 This reaction is essentially the oxidation of primary alcohol using dioxygen to form the corresponding aldehyde and hydrogen peroxide. It has been shown that galactose oxidase is also able to catalyze various primary alcohols other than galactose. In fact, galactose oxidase catalyzes dihydroxyacetone three times faster than it does to galactose. The reaction is regioselective, in that it cannot oxidize secondary alcohol.
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The top 1 mm of the green layer is often gold due to the dominant cyanobacteria and diatom species. Specific cyanobacteria identified are Lyngbya, a sheeted cyanobacterium, and Nostoc and Phormidium, which are filamentous cyanobacteria, and Spirulina spp. Diatom species identified include Navicula. Below this top gold layer extends 5 mm and is dominated by Lyngbya and Oscillatoria species The green layer is also composed of green sulfur bacteria which oxidize sulfur during their growth and are strict photolithotrophs.
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Squalene monooxygenase (also called squalene epoxidase) is an enzyme that uses NADPH and molecular oxygen to oxidize squalene to 2,3-oxidosqualene (squalene epoxide). Squalene epoxidase catalyzes the first oxygenation step in sterol biosynthesis and is thought to be one of the rate-limiting enzymes in this pathway. In humans, squalene epoxidase is encoded by the SQLE gene. Several eukaryote genomes lack a squalene monooxygenase encoding gene, but instead encode an alternative squalene epoxidase that catalyzes the oxidation of squalene.
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Henry John Horstman Fenton (18 February 1854 – 13 January 1929) was a British chemist who, in the 1890s invented Fenton's reagent,Fenton's Reagent Definition Page at toxics.usgs.gov a solution of hydrogen peroxide and an iron catalyst that is used to oxidize contaminants or waste waters. Fenton's reagent can be used to destroy organic compounds such as trichloroethylene (TCE) and tetrachloroethylene (PCE). Born in London, Henry Fenton was educated at Magdalen College School, King's College London and Christ's College, Cambridge.
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During the reaction, oxygen and water molecules oxidize the coal into carbon monoxide (CO), while also releasing hydrogen gas (H2). This used to be done in underground coal mines, and also to make town gas which was piped to customers to burn for illumination, heating, and cooking. : 3C (as Coal) + O2 \+ H2O → H2 \+ 3CO If the refiner wants to produce gasoline, the syngas is routed into a Fischer-Tropsch reaction. This is known as indirect coal liquefaction.
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Graphene does not oxidize in air or in biological fluids, making it an attractive material for use as a biosensor. A graphene circuit can be configured as a field effect biosensor by applying biological capture molecules and blocking layers to the graphene, then controlling the voltage difference between the graphene and the liquid that includes the biological test sample. Of the various types of graphene sensors that can be made, biosensors were the first to be available for sale.
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The fact that our products work so perfectly on dark skin, while those in other brands do not, gives it a unique crossover appeal and superior marketability. Our foundations fit like a second skin, never look two-toned and do not oxidize. Pro Powder is the only powder foundation that does not look ashy on dark skin. Buttercup Liquid Foundation perfectly matches every exotic skin tone and is mask-friendly, with all day rub-off resistance.
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500px 500px Two molecules of farnesyl pyrophosphate then condense to form squalene by the action of squalene synthase in the endoplasmic reticulum. 500px 500px Oxidosqualene cyclase then cyclizes squalene to form lanosterol. Finally, lanosterol is converted to cholesterol through a 19-step process. 500px 500px 500px The final 19 steps to cholesterol contain NADPH and oxygen to help oxidize methyl groups for removal of carbons, mutases to move alkene groups, and NADH to help reduce ketones.
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A fuel-heated boiler must provide air to oxidize its fuel. Early boilers provided this stream of air, or draught, through the natural action of convection in a chimney connected to the exhaust of the combustion chamber. Since the heated flue gas is less dense than the ambient air surrounding the boiler, the flue gas rises in the chimney, pulling denser, fresh air into the combustion chamber. Most modern boilers depend on mechanical draught rather than natural draught.
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Redox (reduction-oxidation) reactions include all chemical reactions in which atoms have their oxidation state changed by either gaining electrons (reduction) or losing electrons (oxidation). Substances that have the ability to oxidize other substances are said to be oxidative and are known as oxidizing agents, oxidants or oxidizers. An oxidant removes electrons from another substance. Similarly, substances that have the ability to reduce other substances are said to be reductive and are known as reducing agents, reductants, or reducers.
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The enzyme 1,2-dihydroxy-6-methylcyclohexa-3,5-dienecarboxylate dehydrogenase uses 1,2-dihydroxy-6-methylcyclohexa-3,5-dienecarboxylate and NAD+ to produce 3-methylcatechol, NADH and CO2. The isofunctional enzymes of catechol 1,2-dioxygenase from species of Acinetobacter, Pseudomonas, Nocardia, Alcaligenes and Corynebacterium oxidize 3-methylcatechol according to both the intradiol and extradiol cleavage patterns. However, the enzyme preparations from Brevibacterium and Arthrobacter have only the intradiol cleavage activity.Extradiol Cleavage of 3-Methylcatechol by Catechol 1,2-Dioxygenase from Various Microorganisms.
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Calcium hypochlorite is a general oxidizing agent and therefore finds some use in organic chemistry. For instance the compound is used to cleave glycols, α-hydroxy carboxylic acids and keto acids to yield fragmented aldehydes or carboxylic acids. Calcium hypochlorite can also be used in the haloform reaction to manufacture chloroform. Calcium hypochlorite can be used to oxidize thiol and sulfide byproducts in organic synthesis and thereby reduce their odour and make them safe to dispose of.
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The disadvantages of LIF connectors are that the grip force between the contacts is lower, and the contacts can oxidize faster and decrease the lifespan of the connector. With the advent of frequent changes in PC processors, a need arose for these systems. Intel introduced the LIF socket system, in which the processor is inserted into the socket, rather than fixed by a lever. This type of socket was used for some types of 386s and early 486s.
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The albumin thiol reacts with radical hydroxyl (.OH), hydrogen peroxide (H2O2) and the reactive nitrogen species as peroxynitrite (ONOO.), and have been shown to oxidize Cys34 to sulfenic acid derivate (HSA-SOH), it can be recycled to mercapto-albumin; however at high concentrations of reactive species leads to the irreversible oxidation to sulfinic (HSA-SO2H) or sulfonic acid (HSA-SO3H) affecting its structure. Presence of reactive oxygen species (ROS), can induce irreversible structural damage and alter protein activities.
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Using the standard Dess–Martin periodinane conditions, alcohols can be oxidized to aldehydes/ketones without affecting furan rings, sulfides, vinyl ethers, and secondary amides. Allylic alcohols are easily oxidized using DMP, which are typically difficult to convert to their respective carbonyls using the typical oxidants. Myers and coworkers determined that DMP could oxidize N-protected- amino alcohols, without epimerization (unlike most other oxidants, including Swern oxidation). These protected amino alcohols can be very important in the pharmaceutical industry.
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The Dess–Martin oxidation is an organic reaction for the oxidation of primary alcohols to aldehydes and secondary alcohols to ketones using Dess-Martin periodinane. It is named after the American chemists Daniel Benjamin Dess and James Cullen Martin who developed the periodinane reagent in 1983. The reaction uses a hypervalent iodine reagent similar to IBX to selectively and mildly oxidize alcohols to aldehydes or ketones. The reaction is commonly conducted in chlorinated solvents such as dichloromethane or chloroform.
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Geobacter is a genus of Proteobacteria. Geobacter species are anaerobic respiration bacterial species which have capabilities that make them useful in bioremediation. Geobacter was found to be the first organism with the ability to oxidize organic compounds and metals, including iron, radioactive metals, and petroleum compounds into environmentally benign carbon dioxide while using iron oxide or other available metals as electron acceptors. Geobacter species are also found to be able to respire upon a graphite electrode.
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The recommended dosing has a low risk profile when taken occasionally in a well hydrated state. As with all medications containing paracetamol (acetaminophen), concomitant use with alcohol carries a significant risk of hepatotoxicity. The combination of paracetamol with aspirin also creates the risk of renal papillary necrosis if large doses are taken chronically. This is because paracetamol yields a toxic metabolite that can accumulate in the kidney while aspirin works to deplete the glutathione stores necessary to oxidize it.
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Non-whole grain methods of milling are intended to isolate the endosperm, which is ground into flour, with removal of both the husk (bran) and the germ. Removal of bran is aimed at producing a flour with a white rather than a brown color, and eliminating fiber, which reduces nutrition. The germ is rich in polyunsaturated fats (which have a tendency to oxidize and become rancid on storage) and so germ removal improves the storage qualities of flour.
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Argent (Ger. ', ', ', or ') is similarly derived from the Latin argentum, "silver". Although sometimes depicted as metallic silver or faint grey, it is more often represented by white, in part because of the tendency for silver paint to oxidize and darken over time, and in part because of the pleasing effect of white against a contrasting colour. Notwithstanding the widespread use of white for argent, some heraldic authorities have suggested the existence of white as a distinct heraldic colour.
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It was dissolved in nitric acid and the bismuth phosphate was precipitated. This step resulted in reducing the gamma radiation by four more orders of magnitude, so the plutonium-bearing solution now had 100,000-th of the original gamma radiation. The plutonium solution was transferred from the 224 buildings to the 221 buildings, through underground pipes. In the fourth step, phosphoric acid was added and the bismuth phosphate precipitated and removed; potassium permanganate was added to oxidize the plutonium.
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Aerobic digestion can also be achieved by using diffuser systems or jet aerators to oxidize the sludge. Fine bubble diffusers are typically the more cost-efficient diffusion method, however, plugging is typically a problem due to sediment settling into the smaller air holes. Coarse bubble diffusers are more commonly used in activated sludge tanks or in the flocculation stages. A key component for selecting diffuser type is to ensure it will produce the required oxygen transfer rate.
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5-Hydroxymethylcytosine was observed by Skirmantas Kriaucionis, an associate at the Heintz lab, who was looking for levels of 5-methylcytosine in two different neuron types. He discovered a significant amount of an unknown substance instead, and after conducting several tests, identified it as being 5-hydroxymethylcytosine.A, T, G, C and What?, popsci.com The lab of L. Aravind used bioinformatic tools to predict that the Tet family of enzymes would likely oxidize 5-methylcytosine to 5-hydroxymethylcytosine.
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Sulfolobus can grow either lithoautotrophically by oxidizing sulfur, or chemoheterotrophically using sulfur to oxidize simple reduced carbon compounds. Heterotrophic growth has only been observed, however, in the presence of oxygen. The principle metabolic pathways are a glycolytic pathway, a pentose phosphate pathway, and the TCA cycle. All Archaea have lipids with ether links between the head group and side chains, making the lipids more resistant to heat and acidity than bacterial and eukaryotic ester-linked lipids.
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Around the Cambrian-Precambrian boundary (541 million years ago), animals begin to mix reduced sulfur from ocean sediments to overlying water causing sulfide to oxidize, which increased the sulfate composition in the ocean. During large extinction events, the sulfate concentration in the ocean was reduced. Although this is difficult to measure directly, seawater sulfur isotope compositions during these times indicates bioturbators influenced the sulfur cycling in the early Earth. Bioturbators have also altered phosphorus cycling on geologic scales.
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Methanol has an advantage of easier storage and transportation and has higher volumetric energy density compared to hydrogen. Also, methanol crossover from anode to cathode is reduced in AAEMFCs compared to PEMFCs, due to the opposite direction of ion transport in the membrane, from cathode to anode. In addition, use of higher alcohols such as ethanol and propanol is possible in AAEMFCs, since anode potential in AAEMFCs is sufficient to oxidize C-C bonds present in alcohols.
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Oxidation primarily occurs with unsaturated fats. For example, even though meat is held under refrigeration or in a frozen state, the poly-unsaturated fat will continue to oxidize and slowly become rancid. The fat oxidation process, potentially resulting in rancidity, begins immediately after the animal is slaughtered and the muscle, intra-muscular, inter-muscular and surface fat becomes exposed to oxygen of the air. This chemical process continues during frozen storage, though more slowly at lower temperature.
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Neptunium(III) hydroxide is quite stable in acidic solutions and in environments that lack oxygen, but it will rapidly oxidize to the IV state in the presence of air. It is not soluble in water. Np(IV) hydroxides exist mainly as the electrically neutral Np(OH)4 and its mild solubility in water is not affected at all by the pH of the solution. This suggests that the other Np(IV) hydroxide, , does not have a significant presence.
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AOPs rely on in-situ production of highly reactive hydroxyl radicals (·OH). These reactive species are the strongest oxidants that can be applied in water and can virtually oxidize any compound present in the water matrix, often at a diffusion controlled reaction speed. Consequently, ·OH reacts unselectively once formed and contaminants will be quickly and efficiently fragmented and converted into small inorganic molecules. Hydroxyl radicals are produced with the help of one or more primary oxidants (e.g.
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Hydrogen peroxide, the simplest peroxide Since molecular oxygen can abstract H atoms from certain radicals, the HOO· radical is easily created. This particular radical can further abstract H atoms, creating H2O2, or hydrogen peroxide; peroxides can further cleave photolytically into two hydroxyl radicals. More commonly, HOO can react with free oxygen atoms to yield a hydroxy radical (·OH) and oxygen gas. In both cases, the ·OH radicals formed can serve to oxidize organic compounds in the atmosphere.
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Expression of PPAR-alpha is highest in tissues that oxidize fatty acids at a rapid rate. In rodents, highest mRNA expression levels of PPAR-alpha are found in liver and brown adipose tissue, followed by heart and kidney. Lower PPAR-alpha expression levels are found in small and large intestine, skeletal muscle and adrenal gland. Human PPAR-alpha seems to be expressed more equally among various tissues, with high expression in liver, intestine, heart, and kidney.
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Long-chain fatty alcohol oxidases vary between species in their specificity; some species have multiple different alcohol oxidases. They generally have a broad range of substrates, ranging from short chain alcohols starting at 4 carbons to the longest long-chain alcohols at 22 carbons. Some can also oxidize select diols, secondary alcohols, hydroxy fatty acids, and even long-chain aldehydes. However, each enzyme is optimized to function for specific alcohol, often between 10 and 16 carbons.
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The electron transport chain in the cell is the site of oxidative phosphorylation. The NADH and succinate generated in the citric acid cycle are oxidized, releasing the energy of O2 to power the ATP synthase. Oxidative phosphorylation (UK , US or electron transport-linked phosphorylation) is the metabolic pathway in which cells use enzymes to oxidize nutrients, thereby releasing the chemical energy stored within in order to produce adenosine triphosphate (ATP). In most eukaryotes, this takes place inside mitochondria.
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Like Ding ware, Ru ware (Wade–Giles: ju) was produced in North China for imperial use. The Ru kilns were near the Northern Song capital at Kaifeng. In similar fashion to Longquan celadons, Ru pieces have small amounts of iron oxide in their glaze that oxidize and turn greenish when fired in a reducing atmosphere. Ru wares range in colour—from nearly white to a deep robin's egg—and often are covered with reddish-brown crackles.
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This reaction occurs at temperatures exceeding 2500 °C (4500 °F), at which the ions in KCl dissociate into free K+ and Cl−. Alternatively, SrCO3 can be added to the candle to produce a red or pink star, but, because it does not oxidize, more oxidizers and fuels must be added to sustain combustion. During combustion, various strontium compounds (especially Sr(OH)2) emit red light, most of which is between 506 and 722 nm in wavelength.
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Unusually, these reactions carried out by the glyoxalase system does not oxidize glutathione, which usually acts as a redox coenzyme. Although aldose reductase can also detoxify methylglyoxal, the glyoxalase system is more efficient and seems to be the most important of these pathways. Glyoxalase I is an attractive target for the development of drugs to treat infections by some parasitic protozoa, and cancer. Several inhibitors of glyoxalase I have been identified, such as S-(N-hydroxy-N-methylcarbamoyl)glutathione.
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The ceramics used in SOFCs do not become electrically and ionically active until they reach very high temperature and as a consequence, the stacks have to run at temperatures ranging from 500 to 1,000 °C. Reduction of oxygen into oxygen ions occurs at the cathode. These ions can then diffuse through the solid oxide electrolyte to the anode where they can electrochemically oxidize the fuel. In this reaction, a water byproduct is given off as well as two electrons.
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Function of FTO could affect the processing of pre-mRNA, other nuclear RNAs, or both. The discovery of the FTO- mediated oxidative demethylation of RNA may initiate further investigations on biological regulation based on reversible chemical modification of RNA, and identification of RNA substrates for which FTO has the highest affinity. FTO can oxidize m6A to generate N6 -hydroxymethyladenosine(hm6A) as an intermediate modification and N6 - formyladenosine(f6A) as a further oxidized product in mammalian cells.
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During photosynthesis, natural electron acceptor NADP is reduced to NADPH in chloroplasts. The following equilibrium reaction takes place. A reduction reaction that stores energy as NADPH: :NADP+ + 2H+ + 2e- -> NADPH + H+ (Reduction) An oxidation reaction as NADPH's energy is used elsewhere: :NADP+ + 2H+ + 2e- <\- NADPH + H+ (Oxidation) Ferredoxin, also known as a NADH+ reductase, is an enzyme that catalyzes the reduction reaction. It is easy to oxidize NADPH but difficult to reduce NADP+, hence a catalyst is beneficial.
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FeBr3 forms a polymeric structure featuring six-coordinate, octahedral Fe centers.Holleman, A. F.; Wiberg, E. "Inorganic Chemistry" Academic Press: San Diego, 2001. . Although inexpensively available commercially, FeBr3 can be prepared by treatment of iron metal with bromine: :2 Fe + 3 Br2 → 2 FeBr3 Above 200 °C, FeBr3 decomposes to ferrous bromide: :2FeBr3 -> 2FeBr2 \+ Br2 Iron(III) chloride is considerably more stable, reflecting the greater oxidizing power of chlorine. FeI3 is not stable, as iron(III) will oxidize iodide ions.
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Aircraft that contain depleted uranium trim weights for stabilizing wings and control surfaces (such as the Boeing 747-100) may contain between 400 and 1,500 kg of DU. This application is controversial because the DU might enter the environment if the aircraft crashes. The metal can also oxidize to a fine powder in a fire. Its use has been phased out in many newer aircraft. Boeing and McDonnell-Douglas discontinued using DU counterweights in the 1980s.
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It is not a good contact for air since the surface will oxidize when exposed. CuW is less likely to erode in air when the concentration of copper is higher in the material. The uses of CuW in the air are as an arc tip, arc plate, and an arc runner. Copper tungsten materials are often used for arcing contacts in medium to high voltage sulfur hexafluoride (SF6) circuit breakers in environments that can reach temperatures above 20,000K.
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The worm has no digestive tract and is wholly reliant on its internal symbionts for nutrition. The bacteria oxidize either hydrogen sulfide or methane, which the host supplies to them. These worms were discovered in the late 1980s at the hydrothermal vents near the Galapagos Islands and have since been found at deep-sea hydrothermal vents and cold seeps in all of the world's oceans. As the endosymbiont adapts to the host's lifestyle, the endosymbiont changes dramatically.
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The second module has 67% identity to CurF and BarG (from Curacin A and Barbamide BGCs) and is predicted to adenylate and heterocyclize a cysteine, as well as oxidize it by FMN-dependent oxidase present in between adenlyation conserved motifs, catalyzing the formation of a thiazole ring (Figure 1C). HctF gene has remarkable similarity to hctE, although, there are two main differences: the iso-valeric acid incorporated does not condensate by the hydroxyl group that substitute an amino group, instead, it condensates be the hydroxyl group in the side chain created by a P450 oxidation (Figure 1B); hctF has an extra thioesterase domain that converts thioester bond to ester bond and catalyze the attack from the C-terminal free hydroxyl group to this newly formed ester, cyclizing the molecule. The final genes hctG and hctH probably encode two P450 that oxidize the side chain of both isovaleric acids (Figure 1D). Lastly, a post-NRPS modification happens in the free hydroxyl group from the second isovaleric acid, adding an acetyl group.
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A mixture of copper and iron sulfides referred to as matte is treated in converters to oxidize iron in the first stage, and oxidize copper in the second stage. In the first stage oxygen enriched air is blown through the tuyeres to partially convert metal sulfides to oxides: :FeS + O2 → FeO + SO2 :CuS + O2 → CuO + SO2 Since iron has greater affinity to oxygen, the produced copper oxide reacts with the remaining iron sulfide: :CuO + FeS → CuS + FeO The bulk of the copper oxide is turned back into the form of sulfide. In order to separate the obtained iron oxide, flux (mainly silica) is added into the converter. Silica reacts with iron oxide to produce a light slag phase, which is poured off through the hood when the converter is tilted around the rotation axis: :2 FeO + SiO2 → Fe2SiO4 (sometimes denoted as 2FeO•SiO2, fayalite) After the first portion of slag is poured off the converter, a new portion of matte is added, and the converting operation is repeated many times until the converter is filled with the purified copper sulfide.
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Standard solutions can be prepared from different Ce4+ salts, but often cerium sulfate is chosen. Since cerimetry is linked to the Fe3+/Fe2+ redox pair, it can be used for analyses of nonstoichiometric levels that either oxidize Fe2+ or reduce Fe3+. For the case of oxidation, a precise excess of high-purity crystalline Mohr's salt is added upon the oxide digestion in aqueous hydrogen chloride (HCl), while for the case of reduction, an excess of 1 M iron trichloride (FeCl3) is added. In both cases, Fe2+ ions will be titrated subsequently. Because the Ce4+ solution is prone to hydrolysis, the titration is done in a strongly HCl-acidic solution into which some phosphoric acid (H3PO4) is added to obtain a less colored phosphato complex of Fe3+. According to tabulated values of standard potentials at pH = 0 for the first-row transition metals, any nonstoichiometry below the following oxidation states will reduce 1 M FeCl3 solution whereas any nonstoichiometry above them will oxidize the Mohr's salt: Ti4+, V4+, Cr3+, Mn2+, Co2+, and Ni2+.
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This process operates on the majority of non-halide substrates. The first step is identical followed by: : [Fe(IV)=O...Por•+] + RH → [Fe(IV)=O...Por] + R• \+ H+ : [Fe(IV)=O...Por] + RH → [Fe(IV)=O...Por] + R• \+ H2O The physiological implications of this second mechanism are important. Eosinophil peroxidase has been demonstrated to oxidize tyrosine residues on proteins, which has also been implicated in reactive oxygen signalling cascades. The third and less relevant mechanism is the catalase activity of peroxidases.
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From 1903 until the World War I era, potassium nitrate for black powder and fertilizer was produced on an industrial scale from nitric acid produced using the Birkeland–Eyde process, which used an electric arc to oxidize nitrogen from the air. During World War I the newly industrialized Haber process (1913) was combined with the Ostwald process after 1915, allowing Germany to produce nitric acid for the war after being cut off from its supplies of mineral sodium nitrates from Chile (see nitratite).
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This affinity to surface sites can be attributed to covalent bonding. When compared to outer sphere complexes that have water molecules separating ions from ligands, inner sphere complexes have surface hydroxyl groups that function as \sigma -donor ligands, increasing the coordinated metal ion's electron density. This is an example of competitive complex formation, in which ligands will compete for space on an activation site of a metal ion. Surface structures are able to reduce and oxidize ligands, whereas transport phenomena do not.
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The flavin-containing monooxygenase (FMO) protein family specializes in the oxidation of xeno-substrates in order to facilitate the excretion of these compounds from living organisms. These enzymes can oxidize a wide array of heteroatoms, particularly soft nucleophiles, such as amines, sulfides, and phosphites. This reaction requires an oxygen, an NADPH cofactor, and an FAD prosthetic group. FMOs share several structural features, such as a NADPH binding domain, FAD binding domain, and a conserved arginine residue present in the active site.
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Since the food is only partly submerged, it must be turned over partway through the cooking process. Some cooks recommend cooking the "presentation" side of the food first, since this side will be better browned. Studies have shown that the margarine, virgin olive oil and similar cooking oils oxidize and destabilize substantially when they are shallow-fried, especially when compared to oils used during baking. In turn, a large amount of heat-sensitive nutrients may degrade and antioxidant properties are lost.
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In 1889 Dow received his first patent after inventing a more cost-effective and streamlined process for bromine extraction. He quickly formed his own company but was bankrupt within the year. His associates were impressed with his work and in 1890 helped him to found the Midland Chemical Company in Midland, Michigan. Dow continued his work extracting bromine, and by early 1891 he had invented the Dow process, a method of bromine extraction using electrolysis to oxidize bromide to bromine.
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Moisture activates the iron, and it oxidizes to form iron oxide. Typically, there must be at least 65% relative humidity in the surrounding atmosphere before the rusting process can begin. To assist in the process of oxidation, sodium chloride is added to the mixture, acting as a catalyst or activator, causing the iron powder to be able to oxidize even with relatively low humidity. As oxygen is consumed to form iron oxide the level of oxygen in the surrounding atmosphere is reduced.
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Darensbourg has pioneered the development of synthetic mimics of hydrogenase enzymes. These include synthetic complexes featuring Fe-based organometallics species, which serve as precursor for producing iron only Hydrogenase enzyme active site. These enzymes are capable of carry out reaction even in the absence of the protein- based active site organization or carry out the proton production with high efficiencies. However, these hydrogenase enzymes were found to be highly sensitive with oxygen (O2), which can over oxidize and inactivate them.
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The goal of the antidote was to generate a large pool of ferric iron (Fe3+) to compete for cyanide with cytochrome a3 (so that cyanide will bind to the antidote rather than the enzyme). The nitrites oxidize hemoglobin to methemoglobin, which competes with cytochrome oxidase for the cyanide ion. Cyanmethemoglobin is formed and the cytochrome oxidase enzyme is restored. The major mechanism to remove the cyanide from the body is by enzymatic conversion to thiocyanate by the mitochondrial enzyme rhodanese.
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Fragile items and sharp edges will be dulled or damaged from colliding with other items and/or thermal stress. Sterling silver and pewter will oxidize and discolour from the heat and from contact with metals lower on the galvanic series such as stainless steel. Pewter has a low melting point and may warp in some dishwashers. Glued items, such as hollow-handle knives or wooden cutting boards, will melt or soften in a dishwasher; high temperatures and moisture damage wood.
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Copper nanoparticles that are extremely small and have a high surface to volume ratio can also serve as antifungal/antibacterial agents. The antimicrobial activity is induced by their close interaction with microbial membranes and their metal ions released in solutions. As the nanoparticles oxidize slowly in solutions, cupric ions are released from them and they can create toxic hydroxyl free radicals when the lipid membrane is nearby. Then, the free radicals disassemble lipids in cell membranes through oxidation to degenerate the membranes.
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NovaBay Pharmaceuticals, Inc. was founded by Ron Najafi, an organic chemist who had previously worked for several pharmaceutical, chemical, and biotech companies in the U.S. Najafi became intrigued by HOCl, hypochlorous acid, an antimicrobial substance produced by White Blood Cells while investigating the chemical reaction of White Blood Cells during oxidative burst cycle. HOCl and other chlorine-containing chemicals fight invading microbes. These natural substances rapidly oxidize the cell walls of bacteria and the protein coats of viruses, rendering them inactive.
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A pyrite cube (center) has dissolved away from a host rock, leaving behind trace gold Iron pyrite is unstable at Earth's surface: iron pyrite exposed to atmospheric oxygen and water decomposes into iron oxides and sulfate. This process is accelerated by the action of Acidithiobacillus bacteria which oxidize pyrite to produce ferrous iron, sulfate, and protons (). These reactions occur more rapidly when pyrite is finely dispersed (framboidal crystals initially formed by sulfate reducing bacteria (SRB) in argillaceous sediments or dust from mining operations).
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The bacterium is chemolithotrophic and is capable of using nitrate as the terminal electron acceptor in the electron transport chain. The organism will oxidize hydrogen sulfide (H2S) into elemental sulfur (S). This is deposited as granules in its periplasm and is highly refractile and opalescent, making the organism look like a pearl. While the sulfide is available in the surrounding sediment, produced by other bacteria from dead microalgae that sank down to the sea bottom, the nitrate comes from the above seawater.
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Both chlorophyll and singlet oxygen then remove hydrogen ions from the unsaturated lipids present in de cells and the organelle membranes, forming lipid radicals. These radicals will oxidize other lipids and proteins, eventually resulting in loss of the membrane integrity of the cells and organelles. This will result in a loss of chlorophyll, leakage of cellular contents, cell death, and eventually death of the plant. Woody plants first show yellowing of the leaves before they start to defoliate, eventually they will die.
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Cytochromes P450 (CYPs) are a superfamily of enzymes containing heme as a cofactor that function as monooxygenases. In mammals, these proteins oxidize steroids, fatty acids, and xenobiotics, and are important for the clearance of various compounds, as well as for hormone synthesis and breakdown. In plants, these proteins are important for the biosynthesis of defensive compounds, fatty acids, and hormones. CYP enzymes have been identified in all kingdoms of life: animals, plants, fungi, protists, bacteria, and archaea, as well as in viruses.
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A broad classification for genetic disorders that result from an inability of the body to produce or utilize one enzyme that is required to oxidize fatty acids. The enzyme can be missing or improperly constructed, resulting in it not working. This leaves the body unable to produce energy within the liver and muscles from fatty acid sources. The body's primary source of energy is glucose; however, when all the glucose in the body has been expended, a normal body digests fats.
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Structure of YB2 Yttrium diboride has the same hexagonal crystal structure as aluminium diboride and magnesium diboride – an important superconducting material. Its Pearson symbol is hP3, space group P6/mmm (No 191), a = 0.33041 nm, c = 0.38465 nm and the calculated density is 5.05 g/cm3. In this structure, the boron atoms form graphite like sheets with yttrium atoms between them. YB2 crystals are unstable to moderate heating in air – they start oxidizing at 400 °C and completely oxidize at 800 °C.
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Finally, induction heating systems cannot be used with moldings that have brass or steel inserts because the induction heating process can destroy or oxidize the insert.. For complex parts it can be difficult to get all of the core liquid to drain out in either melt-out process. In order to overcome this the parts may be rotated for up to an hour. Liquid core metal collects on the bottom of the heated bath and is usable for a new core.
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The process of selective oxidation of alcohols to carbonyls had been quite difficult due to the nucleophilic character of the carbonyl intermediate. In the past Cr(VI) and Mn(VII) reagents have been used to oxidize alcohols, however, these reagents are toxic and comparatively expensive. Cesium carbonate can also be used in Suzuki, Heck, and Sonogashira synthesis reactions. Caesium carbonate produces carbonylation of alcohols and carbamination of amines more efficiently than some of the mechanisms that have been introduced in the past.
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D-amino acid oxidase (DAAO; also OXDA, DAMOX) is an enzyme with the function on a molecular level to oxidize D-amino acids to the corresponding α-keto acids, producing ammonia and hydrogen peroxide. This results in a number of physiological effects in various systems, most notably the brain. The enzyme is most active toward neutral D-amino acids, and not active toward acidic D-amino acids. One of its most important targets in mammals is D-Serine in the central nervous system.
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This ensures that the cement used in a site is of the correct composition to meet safety protocols and requirements of customers. In the mining industry, the use of LOI is vital in determining moisture and volatile material present in the rock. Hence when performing whole-rock analysis to determine total volatiles the LOI method is used. In order to remove all volatiles and to oxidize all iron into iron oxides, the temperature of the LOI is set to 900-1000° Celsius.
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Scientists boil the sample and then add 50 ml of nitric acid solution. The color of the mixture will turn from yellow to transparent. After 48 hours when the sample has reached room temperature it is centrifuged, which allows the organic matter to completely oxidize, and the pellet is extracted, mixed with distilled water, and examined on a slide. The ratios of the different specimen of diatoms are counted, which allows scientists to match the area where the victim entered the water.
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The discovery of nanostructured carbon allotropes such as carbon nanotubes, fullerenes, or graphene promoted further developments. Oxidized carbon nanotubes were used to dehydrogenate n-butane to 1-butene, and to selectively oxidize acrolein to acrylic acid. Fullerenes were used in the catalytic reduction of nitrobenzene to aniline in the presence of H2. Graphene oxide was used as a carbocatalyst to facilitate the oxidation of alcohols to the corresponding aldehydes/ketones (shown in the picture), the hydration of alkynes, and the oxidation of alkenes.
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Nitrous oxide is used because it dissolves easily into the cream, and does not cause the cream to oxidize while it is in the can. Cream must have a minimum fat content of 28% to produce whipped cream with a dispenser. The recipe for the cream to be whipped typically calls for heavy cream and sugar, along with any desired flavorings or colorings. In a sealed container, this cream is pressurized with nitrous oxide, which dissolves into the cream as per its lipophilicity.
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Time-resolved hydroxyl radical protein footprinting employing mass spectrometry analysis was developed in the late 1990s in synchrotron radiolysis studies. The same year, these authors reported on the use of an electrical discharge source to effect the oxidation of proteins on millisecond timescales as proteins pass from the electrosprayed solution into the mass spectrometer. These approaches have since been used to determine protein structures, protein folding, protein dynamics, and protein–protein interactions. Unlike nucleic acids, proteins oxidize rather than cleave on these timescales.
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Chalcone isomerase (CHI) then isomerizes trihydroxychalcone to liquiritigenin, the precursor to daidzein. A radical mechanism has been proposed in order to obtain daidzein from liquiritigenin, where an iron-containing enzyme, as well as NADPH and oxygen cofactors are used by a 2-hydroxyisoflavone synthase to oxidize liquiritigenin to a radical intermediate (C). A 1,2 aryl migration follows to form (D), which is subsequently oxidized to (E). Lastly, dehydration of the hydroxy group on C2 occurs through 2-hydroxyisoflavanone dehydratase to give daidzein.
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Some species of bacteria obtain their energy in the absence of oxygen by oxidizing various fuels while reducing arsenate to arsenite. Under oxidative environmental conditions some bacteria use arsenite as fuel, which they oxidize to arsenate. The enzymes involved are known as arsenate reductases (Arr). In 2008, bacteria were discovered that employ a version of photosynthesis in the absence of oxygen with arsenites as electron donors, producing arsenates (just as ordinary photosynthesis uses water as electron donor, producing molecular oxygen).
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Cerium is a chemical element with the symbol Ce and atomic number 58. Cerium is a soft, ductile and silvery-white metal that tarnishes when exposed to air, and it is soft enough to be cut with a knife. Cerium is the second element in the lanthanide series, and while it often shows the +3 oxidation state characteristic of the series, it also has a stable +4 state that does not oxidize water. It is also considered one of the rare-earth elements.
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The compound is prepared from an aqueous solution of ethylenediamine and virtually any cobalt(II) salt, such as cobalt(II) chloride. The solution is purged with air to oxidize the cobalt(II)-ethylenediamine complexes to cobalt(III). The reaction proceeds in 95% yield, and the trication can be isolated with a variety of anions. A detailed product analysis of a large-scale synthesis revealed that one minor by-product was [Co(en)2Cl(H2NCH2CH2NH3)]Cl3, which contains a rare monodentate ethylenediamine ligand (protonated).
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In jewelry making, pickling is used to remove the copper oxide layer that results from heating copper and sterling silver during soldering and annealing. A diluted sulfuric acid pickling bath is traditionally used, but may be replaced with citric acid. Sheet steel that undergoes acid pickling will oxidize (rust) when exposed to atmospheric conditions of moderately high humidity. For this reason, a thin film of oil or similar waterproof coating is applied to create a barrier to moisture in the air.
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A2PE-H2 traps ATR and accumulates in outer segments to further oxidize into N-retinylidene-N-retinyl- phosphatidyl-ethanolamine (A2PE). After diurnal disk-shedding and phagocytosis of outer segment by RPE cells, A2PE is hydrolyzed inside the RPE phagolysosome to form A2E. Accumulation of A2E causes toxicity at the primary RPE level and secondary photoreceptor destruction in macular degenerations. Additional diseases that may link to mutations in ABCA4 include fundus flavimaculatus, cone-rod dystrophy, retinitis pigmentosa, and age-related macular degeneration.
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These side-products are also commercially valuable, and the reaction conditions may be altered to produce more of them where needed. However, the separation of acetic acid from these by-products adds to the cost of the process. Under similar conditions and using similar catalysts as are used for butane oxidation, the oxygen in air to produce acetic acid can oxidize acetaldehyde. : 2 CH3CHO + O2 → 2 CH3CO2H Using modern catalysts, this reaction can have an acetic acid yield greater than 95%.
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Illustrative of the oxidative power of this salt is the conversion of an acridine derivative to the corresponding acridine-N-oxide. 350px MPS will also oxidize a sulfide to a sulfone with 2 equivalents. With one equivalent the reaction converting sulfide to sulfoxide is much faster than that of sulfoxide to sulfone, so the reaction can conveniently be stopped at that stage if so desired. 270px MPS can also react with ketones to form dioxiranes, with the synthesis of dimethyldioxirane (DMDO) being representative.
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Explosive volcanic eruptions affect the global climate mainly through injecting sulfur bearing gases into the stratosphere, which oxidize to form sulfate aerosols. Stratospheric sulfur aerosols spread around the globe by the atmospheric circulation, producing surface cooling by scattering solar radiation back to space. This cooling effect on the ocean surface usually lasts for several years as the lifetime of sulfate aerosols is about 2–3 years.Stenchikov, G., Delworth, T. L., Ramaswamy, V., Stouffer, R. J., Wittenberg, A., & Zeng, F. (2009).
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The rather restricted chemistry of krypton in the +2 oxidation state parallels that of the neighboring element bromine in the +1 oxidation state; due to the scandide contraction it is difficult to oxidize the 4p elements to their group oxidation states. Until the 1960s no noble gas compounds had been synthesized. However, following the first successful synthesis of xenon compounds in 1962, synthesis of krypton difluoride () was reported in 1963. In the same year, was reported by Grosse, et al.
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Some of the molecules that are cometabolically degraded by bacteria are xenobiotic, persistent compounds, such as PCE, TCE, and MTBE, that have harmful effects on several types of environments. Co-metabolism is thus used as an approach to biologically degrade hazardous solvents. Cometabolism can be used for the biodegradation of methyl-tert-butyl ether (MTBE): an aquatic environment pollutant. Some Pseudomonas members were found to be able to fully degrade MTBE cometabolically with the enzymes they produce to oxidize n-alkanes (e.g.
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Example of automated system: “Peroxide Fluxer” from CLAISSE Peroxide fusion is used to prepare samples for inductively coupled plasma (ICP), atomic absorption (AA) analysis and wet chemistry. Sodium peroxide (Na2O2) is used to oxidize the sample that becomes soluble in a diluted acid solution. This method allows complete dissolution of numerous refractory compounds like chromite, magnetite, ilmenite, rutile, and even silicon, carbides, alloys, noble metals and materials with high sulfide contents. Peroxide fusion can be performed either manually or with automated systems.
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6β-Hydroxylation and to a lesser extent 16β-hydroxylation are the major transformations. The 6β-hydroxylation of testosterone is catalyzed mainly by CYP3A4 and to a lesser extent CYP3A5 and is responsible for 75 to 80% of cytochrome P450-mediated testosterone metabolism. In addition to 6β- and 16β-hydroxytestosterone, 1β-, 2α/β-, 11β-, and 15β-hydroxytestosterone are also formed as minor metabolites. Certain cytochrome P450 enzymes such as CYP2C9 and CYP2C19 can also oxidize testosterone at the C17 position to form androstenedione.
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Some of the most intense and most active Hydrothermal vents are located along the Endeavour segment, with more than 800 individual known chimneys within the ridge's central region, and a total of five major hydrothermal fields along the ridge. These chimneys release large amounts of sulphur-rich minerals into the water, which allow bacteria to oxidize organic compounds and metabolize anaerobically. This allows for a diverse ecosystem of organisms to exist in the low-oxygen conditions near the seafloor around the ridge.
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ATP can be synthesized from a variety of biochemical precursors. For example, lithotrophs can oxidize minerals such as nitrites or forms of sulfur, such as elemental sulfur, sulfites, and hydrogen sulfide to produce ATP. In photosynthesis, autotrophs produce ATP using light energy, whereas heterotrophs must consume organic compounds, mostly including carbohydrates, fats, and proteins. The amount of energy actually obtained by the organism is lower than the amount released in combustion of the food; there are losses in digestion, metabolism, and thermogenesis.
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Catalytic oxidation are processes that oxidize compounds using catalysts. Common applications involve oxidation of organic compounds by the oxygen in air. Such processes are conducted on a large scale for the remediation of pollutants, production of valuable chemicals, and the production of energy.Gerhard Franz, Roger A. Sheldon "Oxidation" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2000 In petrochemistry, high- value intermediates such as carboxylic acids, aldehydes, ketones, epoxides, and alcohols are obtained by partial oxidation of alkanes and alkenes with dioxygen.
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They increase the rate at which ATP is produced aerobically. Oxidative enzymes are responsible for the browning of fruits like apples. When the surface of apples are exposed to the oxygen in the air, the oxidative enzymes like polyphenol oxidase and catechol oxidase oxidize the fruit (electrons are lost to the air). Such browning can be prevented by cooking the fruit or lowering the pH (which destroys, inactivates, or denatures the enzyme) or by preventing oxygen from getting to the surface (such as by covering the fruit).
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Further information: Trimethylaminuria disorder The trimethylaminuria disorder, also known as fish odor syndrome, causes abnormal FMO3-mediated metabolism or a deficiency of this enzyme in an individual. A person with this disorder has a low capacity to oxidize the trimethylamine (TMA) that comes from their diet to its odourless metabolite TMAO. When this happens, large amounts of TMA are excreted through the individual's urine, sweat, and breath, with a strong fish-like odor. As of today, there is no known cure or treatment for this disorder.
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Before oxygen was abundant, methane gas could reach concentrations hundreds of times greater than today's 1.8 parts per million. Ultraviolet light decomposes methane molecules in the upper atmosphere, causing hydrogen gas to escape into space. Over time, the irreversible atmospheric escape of hydrogen– a powerful reducing agent -caused Earth to oxidize and reach the GOE tipping point. Other studies about Earth's atmospheric oxygen have considered its second increase around 600 million years ago that acted as a precursor to the rise of animal life.
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Tertiary alcohols lacking an alpha hydrogen are selected against and generally do not oxidize in the presence of Fétizon's reagent. The oxidation of an alcohol with an alpha hydrogen sterically hindered by axial hydrogens proceeds slower with Fetizon's reagent Increasing the amount of celite used in the reagent accelerates the rate of the reaction by increasing the surface area available to react. However, increasing the amount of celite past 900 grams per mole of silver(I) carbonate begins to slow the reaction due to dilution effects.
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These quinones can further couple within solution producing numerous dimerizations depending upon their substituents. Fetizon's reagent oxidizes phenols to quinones which can oxidatively couple to one another Amines have been shown to oxidize in the presence of Fétizon's reagent to enamines and iminium cations that have been trapped, but can also be selected against in a compound with more easily oxidized alcohol functionalities. Fétizon's reagent can also being used to facilitate cycloaddition of a 4-hydroxy-2-furoquinilone and an olefin to form dihydrofuroquinolinones.
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Neatsfoot oil is used on a number of leather products, although it has been replaced by synthetic products for certain applications. Items such as baseball gloves, saddles, horse harnesses and other horse tack can be softened and conditioned with neatsfoot oil. If used on important historical objects, neatsfoot oil (like other leather dressings) can oxidize with time and contribute to embrittling.Canadian Conservation Institute, Note 8/2: Care of Alum, Vegetable and Mineral Tanned Leather It also may leave an oily residue that can attract dust.
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Sulfide oxidation can proceed under aerobic or anaerobic conditions. Aerobic sulfide-oxidizing bacteria usually oxidize sulfide to sulfate and are obligate or facultative chemolithoautotrophs. The latter can grow as heterotrophs, obtaining carbon from organic sources, or as autotrophs, using sulfide as the electron donor (energy source) for CO2 fixation. The oxidation of sulfide can proceed aerobically by two different mechanisms: substrate-level phosphorylation, which is dependent on adenosine monophosphate (AMP), and oxidative phosphorylation independent of AMP, which has been detected in several Thiobacilli (T.
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Conversely, the sodium is oxidized or is the electron donor, and thus induces reduction in the other species and is considered the reducing agent. Which of the involved reactants would be reducing or oxidizing agent can be predicted from the electronegativity of their elements. Elements with low electronegativity, such as most metals, easily donate electrons and oxidize – they are reducing agents. On the contrary, many ions with high oxidation numbers, such as , , , , can gain one or two extra electrons and are strong oxidizing agents.
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By far, the most commonly used commercial process for treating acid mine drainage is lime (CaO) precipitation in a high-density sludge (HDS) process. In this application, a slurry of lime is dispersed into a tank containing acid mine drainage and recycled sludge to increase water pH to about 9. At this pH, most toxic metals become insoluble and precipitate, aided by the presence of recycled sludge. Optionally, air may be introduced in this tank to oxidize iron and manganese and assist in their precipitation.
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A 1930s Faturan Shift Knob - Oxidization means this car gear stick knob appears to be a dark cherry color on the outside. Faturan, as a material, displays an extreme example of a characteristic common to most phenolics - surface oxidization. Most phenolic will, over time, oxidize to a darker form of its original color. However, Faturan has the unique characteristic of always oxidizing to a dark red, regardless of the original color. This red color caused the material to become known as ‘cherry amber’ in the Middle East.
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Bone ash is a material often used in cupellation, a process by which precious metals (such as gold and silver) are removed from base metals. In cupellation, base metals in an impure sample are oxidized with the help of lead and are vaporized and absorbed into a porous cupellation material, typically made of magnesium or calcium. This leaves the precious metals which do not oxidize behind. Bone ash's extremely porous and calcareous structure as well as its high melting point makes it an ideal candidate for cupellation.
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Full electronic balancing needs a different cabling style than transformer balancing, which in turn needs a different cabling style than impedance balancing. Mistakes in the interconnection may make the inserted signal drop in level by 6 dB or add hum and buzz or even overheat a balanced output circuit on the external device, decreasing its usable life. Insert jacks themselves can be the source of intermittent signal problems. Internal jack contacts may get too loose over time and they may oxidize, impeding electrical conduction.
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Desiccants are intended to absorb water vapour. Desiccant media used in HP breathing air filters include: activated alumina, silica gel, sorbead, and molecular sieve. Some grades of molecular sieve can absorb up to 23% of its own weight in water, can produce dew points of , and have additional capacities for absorbing hydrocarbons, carbon dioxide, and other organics, and function at up to 120 degrees Fahrenheit. Manganese dioxide based catalysts (Monoxycon and Hopcalite 300) is used to oxidize carbon monoxide into much less toxic carbon dioxide.
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This chemoautotrophic Archaea crenarchaeon Candidatus can oxidize ammonium as their energy source without oxygen, which could significantly impact the nitrogen and carbon cycles. One study estimates these ammonium-oxidizing bacteria, which are only 5% of the microbial population, can annually capture 1.1 Gt of organic carbon. Microbial biomass and diversity typically decline exponentially with depth in the mesopelagic zone, tracking the general decline of food from above. The community composition varies with depths in the mesopelagic as different organisms are evolved for varying light conditions.
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This has led to the development of biochemical and biomolecular markers for assessing intrinsic biodegradation occurring in difficult to access groundwater aquifers. In keeping with her interest in microbial processes in the environment, recent work has also focused on the ability of environmental microorganisms to oxidize or to reduce hazardous metals such as arsenic. Through their ability to change the oxidation state of the metal ions the microorganisms can affect the fate and transport of the metals in aqueous habitats such as streams and groundwater.
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For many years, the strong oxidizing agent potassium permanganate (KMnO4) was used for measuring chemical oxygen demand. Measurements were called oxygen consumed from permanganate, rather than the oxygen demand of organic substances. Potassium permanganate's effectiveness at oxidizing organic compounds varied widely, and in many cases biochemical oxygen demand (BOD) measurements were often much greater than results from COD measurements. This indicated that potassium permanganate was not able to effectively oxidize all organic compounds in water, rendering it a relatively poor oxidizing agent for determining COD.
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Pure platinum is a lustrous, ductile, and malleable, silver-white metal. Platinum is more ductile than gold, silver or copper, thus being the most ductile of pure metals, but it is less malleable than gold.CRC press encyclopedia of materials and finishes, 2nd edition, Mel Schwartz, 2002Materials handbook, fifteenth edition, McGraw-Hill, by John Vaccari, 2002 The metal has excellent resistance to corrosion, is stable at high temperatures and has stable electrical properties. Platinum does oxidize, forming PtO2, at 500 °C; this oxide can be easily removed thermally.
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CD-ROMs/DVD-ROMs (read-only-memory) are commercial grade discs and use a metallic data layer created using a molding machine that stamps pits (depressions) and lands (flat surfaces) into a polycarbonate substrate base. The metal layer is then applied to the base, creating the data layer. While aluminium is most frequently used, it can potentially oxidize and lose data, a process sometimes called "disk rot". For archival discs, silver or gold layers are preferred because of longer life expectancies and better reflectivity.
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It was common for ancient Egyptians to be covered in jewellery because they believed it made them more attractive to the Gods. The upper class Egyptians were fascinated with gold jewelry. They believe that gold is the color of the sun, and it symbolises the sun's permanence and immortality, because this metal does not corrode or oxidize with time. Accessories were often embellished with inlaid precious and semi-precious stones such as emeralds, pearls, and lapis lazuli, to create intricate patterns inspired from nature.
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Due to its ability to oxidize pyrite (FeS2), M. sedula has the potential to be used for coal depyritization. With increased awareness of the environmental impact of the combustion of coals, the idea of coal pollution mitigation or “clean coal” was born. While there are several focuses of mitigation, one of which is the removal of impurities, such as sulfur found in pyrite, prior to combustion. The combustion of sulfur leads to the formation of SO2, which has adverse health effects, and contributes to acid rain.
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Some degree of humidity is required in order to keep wines with cork enclosures from drying out. Even when wine bottles are stored on their sides, one side of the cork is still exposed to air. Should the cork begin to dry out, it can allow oxygen to enter the bottle, filling the ullage space and possibly causing the wine to spoil or oxidize. Excessive humidity can also pose the risk of damaging wine labels, which may hinder identification or hurt potential resale value.
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450px Pyruvate decarboxylation requires a few cofactors in addition to the enzymes that make up the complex. The first is thiamine pyrophosphate (TPP), which is used by pyruvate dehydrogenase to oxidize pyruvate and to form a hydroxyethyl- TPP intermediate. This intermediate is taken up by dihydrolipoyl transacetylase and reacted with a second lipoamide cofactor to generate an acetyl-dihydrolipoyl intermediate, releasing TPP in the process. This second intermediate can then be attacked by the nucleophilic sulfur attached to Coenzyme A, and the dihydrolipoamide is released.
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Ehrlich's reagent is also used as a stain in thin layer chromatography and as a reagent to detect urobilinogen in fresh, cool urine. If a urine sample is left to oxidize in air to form urobilin the reagent will not detect the urobilinogen. By adding few drops of reagent to 3 mL of urine in a test tube one can see a change of color, to dark pink or red. The degree of color change is proportional to the amount of urobilinogen in the urine sample.
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Huntsman's process was the first to produce a fully homogeneous steel. Unlike previous methods of steel production, the Huntsman process was the first to fully melt the steel, allowing the full diffusion of carbon throughout the liquid. With the use of fluxes it also allowed the removal of most impurities, producing the first steel of modern quality. Due to carbon's high melting point (nearly triple that of steel) and its tendency to oxidize (burn) at high temperatures, it cannot usually be added directly to molten steel.
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One of today's most widely accepted air pollution control technologies across industry is a regenerative thermal oxidizer, commonly referred to as a RTO. RTOs use a ceramic bed which is heated from a previous oxidation cycle to preheat the input gases to partially oxidize them. The preheated gases enter a combustion chamber that is heated by an external fuel source to reach the target oxidation temperature which is in the range between and . The final temperature may be as high as for applications that require maximum destruction.
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Energy generation via methane oxidation yields the next best source of energy after sulfur oxidation. It has been suggested that microbial oxidation facilitates rapid turnover at hydrothermal vents, thus much of the methane is oxidize within short distance of the vent. In hydrothermal vent communities, aerobic oxidation of methane is commonly found in endosymbiotic microbes of vent animals. Anaerobic oxidation of methane (AOM) is typically coupled to reduction of sulfate or Fe and Mn as terminal electron acceptors as these are most plentiful at hydrothermal vents.
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Shú pu'er tea, shúchá, brewed from a brick Pu'er or pu-erh is a variety of fermented tea traditionally produced in Yunnan Province, China. In the context of traditional Chinese tea production terminology, fermentation refers to microbial fermentation (called 'wet piling'), and is typically applied after the tea leaves have been sufficiently dried and rolled. As the tea undergoes controlled microbial fermentation, it also continues to oxidize, which is also controlled, until the desired flavors are reached. This process produces tea known as 黑茶 hēichá (lit.
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TET processivity can be viewed at three levels, the physical, chemical and genetic levels. Physical processivity refers to the ability of a TET protein to slide along the DNA from one CpG site to another. An in vitro study showed that DNA-bound TET does not preferentially oxidize other CpG sites on the same DNA molecule, indicating that TET is not physically processive. Chemical processivity refers to the ability of TET to catalyze the oxidation of 5mC iteratively to 5caC without releasing its substrate.
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Zirconium hydrides form upon interaction of the metal with hydrogen gas. Whereas this reaction occurs even at room temperature, homogeneous bulk hydrogenation is usually achieved by annealing at temperatures of 400–600 °C for a period between several hours and a few weeks. At room temperature, zirconium hydrides quickly oxidize in air, and even in high vacuum. The formed nanometer-thin layer of oxide stops further oxygen diffusion into the material, and thus the change in composition due to oxidation can usually be neglected.
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Deficiencies in acyl-CoA dehydrogenases result in decreased ability to oxidize fatty acids, thereby signifying metabolic dysfunction. Medium-chain acyl-CoA dehydrogenase deficiencies (MCADD) are well known and characterized because they occur most commonly among acyl-CoA dehydrogenases, leading to fatty acid oxidation disorders and the potential of life-threatening metabolic diseases. Some symptoms of medium-chain acyl-CoA dehydrogenase deficiency include intolerance to fasting, hypoglycemia, and sudden infant death syndrome. These symptoms are seen as directly connected to the inability to metabolize fats.
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The element must not be damaged by minor harmless surges of current, and must not oxidize or change its behavior after possibly years of service. The fuse elements may be shaped to increase heating effect. In large fuses, current may be divided between multiple strips of metal. A dual-element fuse may contain a metal strip that melts instantly on a short circuit, and also contain a low-melting solder joint that responds to long-term overload of low values compared to a short circuit.
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Oxidation of organics to CO is most commonly achieved in liquid solutions by the creation of the highly oxidizing chemical species, the hydroxyl radical (OH•). Organic oxidation in a combustion environment involves the creation of other energized molecular oxygen species. For the typical TOC levels in UPW systems most methods utilize hydroxyl radicals in the liquid phase. There are multiple methods to create sufficient concentrations of hydroxyl radicals needed to completely oxidize the organics in water to CO, each method being appropriate for different water purity levels.
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The phenols oxidize and polymerize under the action of an enzyme laccase, yielding a substrate that, upon proper evaporation of its water content, is hard. These lacquers produce very hard, durable finishes that are both beautiful and very resistant to damage by water, acid, alkali or abrasion. The active ingredient of the resin is urushiol, a mixture of various phenols suspended in water, plus a few proteins. The resin is derived from trees indigenous to East Asia, like lacquer tree Toxicodendron vernicifluum, and wax tree Toxicodendron succedaneum.
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The Pourbaix diagram for titanium in pure water, perchloric acid, or sodium hydroxidePuigdomenech, Ignasi (2004) Hydra/Medusa Chemical Equilibrium Database and Plotting Software, KTH Royal Institute of Technology. Like aluminium and magnesium, titanium metal and its alloys oxidize immediately upon exposure to air. Titanium readily reacts with oxygen at in air, and at in pure oxygen, forming titanium dioxide. It is, however, slow to react with water and air at ambient temperatures because it forms a passive oxide coating that protects the bulk metal from further oxidation.
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Borderline hydrides exhibit bonding characteristics between ionic and covalent bond types. A specific examples of a borderline hydride CuH, copper hydride, that appears as a spongy reddish-brown substance is a moderate reducing agent. It will catalytically oxidize hypophosphorous acid to phosphorous acid at room temperature, and it gives off hydrogen gas when subjected to heat. ZnH2 is also a solid at room temperature that breaks down at 90 °C, but even left alone decomposes over several days to zinc metal and hydrogen gas.
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Fermentation is a specific type of heterotrophic metabolism that uses organic carbon instead of oxygen as a terminal electron acceptor. This means that these organisms do not use an electron transport chain to oxidize NADH to and therefore must have an alternative method of using this reducing power and maintaining a supply of for the proper functioning of normal metabolic pathways (e.g. glycolysis). As oxygen is not required, fermentative organisms are anaerobic. Many organisms can use fermentation under anaerobic conditions and aerobic respiration when oxygen is present.
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Silicon carbide and carbon (graphite) are two other refractory materials used in some very severe temperature conditions, but they cannot be used in contact with oxygen, as they would oxidize and burn. Binary compounds such as tungsten carbide or boron nitride can be very refractory. Hafnium carbide is the most refractory binary compound known, with a melting point of 3890 °C.Hafnium, Los Alamos National Laboratory The ternary compound tantalum hafnium carbide has one of the highest melting points of all known compounds (4215 °C).
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FTR is unique among thioredoxin reductases because it uses an Fe-S cluster cofactor rather than flavoproteins to reduce disulfide bonds. FTR catalysis begins with its interaction with reduced Ferredoxin. This proceeds with the attraction between FTR Lys-47 and Ferredoxin Glu-92. One electron from Ferredoxin and one electron from the Fe-S center is abstracted to break FTR's Cys-87 and Cys-57 disulfide bond, create a nucleophilic Cys-57, and oxidize the Fe-S center from [4Fe-4S]2+ to [4Fe-4S]3+.
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The final test was the Kiwi B4E test on 28 August in which the reactor was operated for twelve minutes, eight of which were at full power (937 MW). This was the first test to use uranium carbide pellets instead of uranium oxide, with a niobium carbide coating. These were found to oxidize on heating, causing a loss of carbon in the form of carbon monoxide gas. To minimize this, the particles were made larger ( in diameter), and given a protective coating of pyrolytic graphite.
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Copper sweetening is a petroleum refining process using a slurry of clay and cupric chloride to oxidize mercaptans. The resulting disulfides are less odorous and usually very viscous, and are usually removed from the lower- boiling fractions and left in the heavy fuel oil fraction. Copper sweetening introduces trace amount of copper into the resulting products, which tends to have detrimental effects as it leads to formation of gummy residues. Other sources of copper include contact with refinery parts made of copper and copper alloys.
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Early 20th century hand-coloured photographs were often mounted on mat-board, placed behind a glass frame, and backed by wood panel slats, cardboard, or heavy paperboard. A backing sheet was often glued to the back of the mat-board. Unfortunately, the paper products produced and used during the late-19th and early-20th centuries are highly acidic and will cause yellowing, brittling and degradation of hand- coloured photographs. Metallic inclusions in the paper can also oxidize which may be the cause of foxing in paper materials.
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The bulking and cutting strategy is effective because there is a well- established link between muscle hypertrophy and being in a state of positive energy balance.the science and development of muscle hypertrophy, Dr. Brad Schoenfeld, page 139-140 A sustained period of caloric surplus will allow the athlete to gain more fat-free mass than they could otherwise gain under eucaloric conditions. Some gain in fat mass is expected, which athletes seek to oxidize in a cutting period while maintaining as much lean mass as possible.
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When the wrap is removed from its sealed pouch and exposed to oxygen, the disks oxidize, producing an exothermic reaction. When this product was applied to the low back muscles, it provided greater pain relief for 24 hours after application when compared to ibuprofen, acetaminophen, and no treatment. When the same product was applied to the wrist, it decreased pain and improved range of motion (ROM) in patients experiencing wrist pain. Scientists have tested the ability of these topical wraps to increase paraspinal muscle temperatures.
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Oxidation of ions or neutral molecules occurs at the anode. For example, it is possible to oxidize ferrous ions to ferric ions at the anode: : Fe(aq) → Fe(aq) + e− Reduction of ions or neutral molecules occurs at the cathode. It is possible to reduce ferricyanide ions to ferrocyanide ions at the cathode: :Fe(CN) + e− → Fe(CN) Neutral molecules can also react at either of the electrodes. For example: p-Benzoquinone can be reduced to hydroquinone at the cathode: 35px + 2 e− \+ 2 H+ → Image:Hydrochinon2.
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In the Olin Raschig process, chlorine-based oxidants oxidize ammonia without the presence of a ketone. In the peroxide process, hydrogen peroxide oxidizes ammonia in the presence of a ketone. Hydrazine is produced in the Olin-Raschig process from sodium hypochlorite (the active ingredient in many bleaches) and ammonia, a process announced in 1907. This method relies on the reaction of monochloramine with ammonia to create the nitrogen–nitrogen single bond as well as a hydrogen chloride byproduct: : NH2Cl + NH3 -> H2NNH2 + HCl Related to the Raschig process, urea can be oxidized instead of ammonia.
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The advantage of using permanganate in ISCO is that it reacts comparatively slowly in the subsurface which allows the compound to move further into the contaminated space and oxidize more contaminants. Permanganate can also help with the cleanup of materials that are not very permeable. In addition, because both sodium permanganate and potassium permanganate solutions have a density greater than water's density, permanganate can travel through the contaminated area through density-driven diffusion. The use of permanganate creates the byproduct , which is naturally present in the soil and is therefore a safe byproduct.
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It is probably performed also by the Brocadiales, an order of Planctomycetes that oxidize ammonia in anaerobic condition. Hydrogenotrophic methanogenesis, which is only found in certain archaea and accounts for 80% of global methanogenesis, is also based on the reductive acetyl CoA pathway. The Carbon Monoxide Dehydrogenase/Acetyl-CoA Synthase is the oxygen-sensitive enzyme that permits the reduction of CO2 to CO and the synthesis of acetyl-CoA in several reactions. One branch of this pathway, the methyl branch, is similar but non- homologous between bacteria and archaea.
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This allows the use of water, one of the most abundant substances on Earth, as an electron donor—as a source of reducing power. The release of free oxygen is a side-effect of enormous consequence. The first step uses the energy of sunlight to oxidize water to O2, and, ultimately, to produce ATP :ADP + Pi ATP + H2O and the reductant, NADPH :NADP+ \+ 2e− \+ 2H+ NADPH + H+ In the second step, called the Calvin cycle, the actual fixation of carbon dioxide is carried out. This process consumes ATP and NADPH.
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The stable quinolone monoadducts oxidize to form 8-hydroxydeoxyguanosine (8OHdG), which, if left unrepaired, lead to transversions of guanines to thymines, which are nucleotides in DNA. Despite the direct mutagenic properties of 4HAQO, it is less toxic than 4NQO, indicating that metabolism of 4NQO produces other reactive chemicals such as anion radical metabolites. Yeast species have been used to map polymorphic regions in response to 4NQO, identifying the polymorphic transcription factor Yrr1. Yrr1 confers 4NQO resistance to wild-type S. cerevisiae yeast, binding upstream from core genes well-known to regulation drug response.
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The corrosive wear occurs in the presence of metals that oxidize or corrode. When the pure metal surfaces come into contact with the surrounding environment, oxide films are created on their surfaces because of the contaminants present in the environment itself, such as water, oxygen or acids. These films are continually removed from the abrasive and adhesive wear mechanisms, continually recreated by pure- contaminating metal interactions. Clearly this type of wear can be reduced by trying to create an 'ad hoc' environment, free of pollutants and sensible to minimal thermal changes.
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The average human digestive system produces approximately 3g of ethanol per day through fermentation of its contents.ETHANOL, ACETALDEHYDE AND GASTROINTESTINAL FLORA Jyrki Tillonen PDF Catabolic degradation of ethanol is thus essential to life, not only of humans, but of all known organisms. Certain amino acid sequences in the enzymes used to oxidize ethanol are conserved (unchanged) going back to the last common ancestor over 3.5bya. Such a function is necessary because all organisms produce alcohol in small amounts by several pathways, primarily through fatty acid synthesis, glycerolipid metabolism, and bile acid biosynthesis pathways.
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If a poisoned person is able to survive for 6 to 12 hours subsequent to initial dose, they have a good prognosis. The patient should be kept in a quiet and darkened room, because excessive manipulation and loud noises may cause convulsions. Because these convulsions are extremely painful, appropriate analgesics should be administered. Treatment of strychnine poisoning involves oral administration of activated charcoal which adsorbs strychnine within the digestive tract; unabsorbed strychnine is removed from the stomach by gastric lavage, along with tannic acid or potassium permanganate solutions to oxidize strychnine.
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It is one of the most commonly used compressed gases for pneumatic (pressurized gas) systems in portable pressure tools. Carbon dioxide is also used as an atmosphere for welding, although in the welding arc, it reacts to oxidize most metals. Use in the automotive industry is common despite significant evidence that welds made in carbon dioxide are more brittle than those made in more inert atmospheres. It is used as a welding gas primarily because it is much less expensive than more inert gases such as argon or helium.
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Vitamin C (or ascorbic acid) is present in the grape and the must up to 50 milligrams per litre. It is a protection in the wort against the oxidation phenomenon. In the presence of oxygen it produces hydrogen peroxide; by this reaction it deprives the enzymes in the wort of oxygen that is necessary to oxidize the wine. Since 1962 the addition of vitamin C in the wine has been allowed to a maximum of 15 grams per hectolitre at the time of packaging to stabilize the wine.
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For example, hydrogen peroxide together with 4 amino-antipyrene (4-AAP) and phenol in the presence of peroxidase yield a red quinoeimine dye that can be measured at 505 nm. The absorbance at 505 nm is proportional to concentration of glucose in the sample. Enzymatic glucose biosensors use an electrode instead of O2 to take up the electrons needed to oxidize glucose and produce an electronic current in proportion to glucose concentration. This is the technology behind the disposable glucose sensor strips used by diabetics to monitor serum glucose levels.
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In particular, chimeric hemoglobins found in fungi and giant annelids may contain both globin and other types of proteins. One of the most striking occurrences and uses of hemoglobin in organisms is in the giant tube worm (Riftia pachyptila, also called Vestimentifera), which can reach 2.4 meters length and populates ocean volcanic vents. Instead of a digestive tract, these worms contain a population of bacteria constituting half the organism's weight. The bacteria oxidize H2S from the vent with O2 from the water to produce energy to make food from H2O and CO2.
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Dimethyl sulfide, a byproduct of the Swern oxidation, is one of the strongest odours known in organic chemistry. Humans can detect this compound in concentrations as low as 0.02 to 0.1 parts per million. A simple remedy for this problem is to rinse used glassware with bleach or oxone solution, which will oxidize the dimethyl sulfide back to dimethyl sulfoxide or to dimethyl sulfone, both of which are odourless and nontoxic. The reaction conditions allow oxidation of acid- sensitive compounds, which might decompose under the acidic oxidation conditions such as Jones oxidation.
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A major factor reducing the lifetime of primary cells is that they become polarized during use. This means that hydrogen accumulates at the cathode and reduces the effectiveness of the cell. To reduce the effects of polarization in commercial cells and to extend their lives, chemical depolarization is used; that is, an oxidizing agent is added to the cell, to oxidize the hydrogen to water. Manganese dioxide is used in the Leclanché cell and zinc–carbon cell, and nitric acid is used in the Bunsen cell and Grove cell.
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One of the classic flavor notes associated with Arneis is that of ripe pears. The Arneis vine can be a difficult grape to cultivate, with naturally low acidity and tendency to get over ripe if it is harvested after September. Additionally, the vine is prone to powdery mildew though recent cloning research has begun to isolate clones of Arneis that have more tolerance to mildew. The vine's propensity for low crop yields and for the wine to oxidize easily, contributed to its steady decline in the early to mid 20th century.
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Tryptophan 7-halogenase is a member of a class of enzymes known as flavin-dependent halogenases. Prior to tryptophan 7-halogenase's discovery, it was thought that all halogen atoms in metabolites were incorporated by the action of haloperoxidases, another class of halogenases dependent on metal centers such as vanadium or heme, or perhydrolases, a class of halogenases that generates peracids that in turn oxidize halide ions to hypohalous acids, which act as halogenating agents. These enzymes halogenate without substrate specificity and regioselectivity. The first tryptophan 7-halogenase was isolated in 1995 by Dairi et al.
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In our example there is no [MLn]1+ to oxidize since it has been converted to [ML(n-1)]+ through ligand loss. The return wave can sometimes be observed by increasing the scan rates so the following chemical reaction can be observed before the chemical reaction takes place. This often requires the use of ultramicroelectrodes (UME) capable of very high scan rates of 0.5 to 5.0 V/s. Plots of forward and reverse peak ratios against modified forms of the scan rate often identify the rate of the chemical reaction.
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One example of this is ammonia-oxidizing bacteria has a metabolic feature that in combination with other nitrogen-cycling metabolic activities such as nitrite oxidation and denitrification, to remove nitrogen from wastewater in activated sludge. Since denitrifying bacteria are heterotrophic, an organic carbon source is supplied to the bacteria in an anoxic basin. With no available oxygen, denitrifying bacteria use the oxygen present in the nitrate to oxidize the carbon. This leads to the creation of nitrogen gas from nitrate, which then bubbles up out of the wastewater.
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The mechanism can also be deliberately modified to reduce the turbine efficiency in a pre- defined position. This mode can be selected to sustain a raised exhaust temperature to promote "light-off" and "regeneration" of a diesel particulate filter (this involves heating the carbon particles stuck in the filter until they oxidize away in a semi-self-sustaining reaction - rather like the self- cleaning process some ovens offer). Actuation of a VGT for EGR flow control, or to implement braking or regeneration modes in general, requires hydraulic actuators or electric servos.
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Potassium permanganate is one of the principal chemicals used in the film and television industries to "age" props and set dressings. Its ready conversion to brown MnO2 creates "hundred- year-old" or "ancient" looks on Hessian cloth (burlap), ropes, timber, and glass. Potassium permanganate can be used to oxidize cocaine paste to purify it and increase its stability. This led to the Drug Enforcement Administration launching Operation Purple in 2000, with the goal of monitoring the world supply of potassium permanganate; however, potassium permanganate derivatives and substitutes were soon used thereafter to avoid the operation.
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In the industrial microbial leaching process popularly known as bioleaching, low grade ore is dumped in a large pile (the leach dump) and a dilute sulfuric acid solution (pH 2) is percolated down through the pile. The liquid coming out at the bottom of the pile, rich in the mineral is collected and transported to a precipitation plant where the metal is reprecipitated and purified. The liquid is then pumped back to the top of the pile and the cycle is repeated. Acidithiobacillus ferrooxidans is able to oxidize the Fe2+ in to Fe3+.
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Many fermented teas do not arrive on the market ready for consumption. Instead, they may start as green teas or partially oxidized oolong-like teas, which are then allowed to slowly oxidize and undergo microbial fermentation over many years (comparable to wines that are sold to be aged in a cellar). Alternatively, fermented teas can be created quickly through a ripening process spanning several months, as with most Pu- erh. This ripening is done through a controlled process similar to composting, where the moisture and temperature of the tea are carefully monitored.
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Camp scene from late in the classic period, with no frame (c. 1556-1565), Freer Gallery of Art, Washington, D.C.; Majnun (at top wearing orange) spies on his beloved Layla (standing in tent doorway). The bright and pure colouring of the Persian miniature is one of its most striking features. Normally all the pigments used are mineral-based ones which keep their bright colours very well if kept in proper conditions, the main exception being silver, mostly used to depict water, which will oxidize to a rough-edged black over time.
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Carbon disc, radial caliper front brakes on the 2011 Suzuki MotoGP racing motorcycle Carbon brakes are used in Moto GP. The friction between the carbon discs and carbon pads produces vast amounts of braking force; far greater braking force than conventional steel discs. They operate at very high operating temperatures, typically between 400-1000 °C. Continuous late braking can overheat carbon carbon brakes as they oxidize and wear out faster. The high temperatures needed for carbon carbon brakes to be effective means that they cannot be used in the wet.
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Difluoro and monofluoro alcohols are more difficult to oxidize. Swern oxidation has been used, but a large excess of the oxidant had to be employed, and in some cases did not give reproducible results. Linderman and Graves found DMP was successful in most cases but could not tolerate the presence of nucleophilic functional groups in the alcohol, as these reacted with DMP by displacing acetate. Using the compound shown below produced the desired carbonyls in high yields as the addition of the tert-butoxy group, due to its steric bulk, minimizes these side reactions.
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Hydrogen is the simplest solar fuel to synthesize, since it involves only the transference of two electrons to two protons. It must, however, be done stepwise, with formation of an intermediate hydride anion: :2 e− \+ 2 H+ H+ \+ H− H2 The proton-to-hydrogen converting catalysts present in nature are hydrogenases. These are enzymes that can either reduce protons to molecular hydrogen or oxidize hydrogen to protons and electrons. Spectroscopic and crystallographic studies spanning several decades have resulted in a good understanding of both the structure and mechanism of hydrogenase catalysis.
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Ruthenium tetroxide is a highly aggressive oxidant, but TPAP, which is its one-electron reduced derivative, is a mild oxidizing agent for the conversion of primary alcohols to aldehydes (the Ley oxidation). (review article) Secondary alcohols are similarly oxidized to ketones. It can also be used to oxidize primary alcohols all the way to the carboxylic acid with a higher catalyst loading, larger amount of the co-oxidant, and addition of two equivalents of water. In this situation, the aldehyde reacts with water to form the geminal-diol hydrate, which is then oxidized again.
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The addition of rate-limiting nutrients promotes the microbe's biodegrading pathways, including upregulation of genes encoding multiple alkane hydroxylases that oxidize various lengths of linear alkanes. These enzymes essentially remove the problematic hydrocarbon constituents of petroleum oil while A. borkumensis simultaneously increases synthesis of anionic glucoproteins, which are used to emulsify hydrocarbons in the environment and increase their bioavailability. The presence of crude oil along with appropriate levels of nitrogen and phosphor catalyzes the removal of petroleum either by mechanisms that enhance the efficiency of substrate uptake or by direct biodegradation of aliphatic chains.
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Haloperoxidases are peroxidases that are able to mediate the oxidation of halides by hydrogen peroxide.S.L. Neidleman, J. Geigert (1986) Biohalogenation - principles, basic roles and applications; Ellis Horwood Ltd Publishers; Chichester; Both halides and hydrogen peroxide are widely available in the environment. The Nernst equation shows that hydrogen peroxide can oxidize chloride (E°= 1.36 V), bromide (E°= 1.09 V) and iodide (E°= 0.536 V) from a thermodynamic perspective under natural conditions, i.e., a temperature range of about 0–30 °C and a pH ranging from about 3 (humic soil layer) to about 8 (sea water).
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Carbon nanotubes can also be used for a support for hydrogenase on the electrode due to their ability to assemble in large porous and conductive networks. These hybrids have been prepared using [FeFe] and [NiFe] hydrogenases. The [NiFe] hydrogenase isolated from A. aeolicus (thermophilic bacteria) was able to oxidize H2 with direct electron transfer without a redox mediator with a 10-fold higher catalytic current with stationary CNT-coated electrodes than with bare electrodes. Another way of coupling hydrogenase to the nanotubes was to covalently bind them to avoid a time delay.
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The device was originally a standard platinum laboratory crucible with a perforated base into which asbestos pulp was placed to form the filter mat. The crucible was then heated in an oven to dry out until it attained constant weight. The use of these materials meant that after filtration, the crucible and its contents could be subjected to high temperature to dry the filtrate and possibly oxidize or ash it to minimum weight. However, because of the high cost of platinum, versions made of porcelain were introduced in 1882.
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After rolling is finished, the leaf particles are spread out on a table where they begin to oxidize in the ambient heat and humidity. Controlling the temperature, humidity, and the duration of oxidation requires a great deal of attention, and excessive deviation in the process can spoil the final product. As oxidization continues, the colour of the leaf changes from green to a bright coppery colour. Once oxidation is complete, the fermented leaf is inserted into a firing chamber to denature the enzyme, preventing further chemical reactions from taking place.
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Hydrothermal vents emit hydrogen sulfide that support the carbon fixation of chemolithotrophic bacteria that oxidize hydrogen sulfide with oxygen to produce elemental sulfur or sulfate. The chemical reactions are as follows: CO2 \+ 4H2S + O2 -> CH2O + 4S0 \+ 3H2O CO2 \+ H2S + O2 \+ H2O -> CH2O + SO42- \+ 2H+ In modern oceans, Thiomicrospira, Halothiobacillus, and Beggiatoa are primary sulfur oxidizing bacteria, and form chemosynthetic symbioses with animal hosts. The host provides metabolic substrates (e.g., CO2, O2, H2O) to the symbiont while the symbiont generates organic carbon for sustaining the metabolic activities of the host.
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On the other hand, it catalyzes the oxidation of alkanes to tertiary alcohols, amides to t-butyldioxyamides, and tertiary amines to α-(t-butyldioxyamides) using tert-butyl hydroperoxide. Using other peroxides, oxygen, and acetone, the catalyst can oxidize alcohols to aldehydes or ketones. Using dichlorotris(triphenylphosphine)ruthenium(II) the N-alkylation of amines with alcohols is also possible (see "borrowing hydrogen"). :650px RuCl2(PPh3)3 efficiently catalyzes carbon-carbon bond formation from cross couplings of alcohols through C-H activation of sp3 carbons in the presence of a Lewis acid.
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Color code: carbon, C, blue-gray; fluorine, F, green; cerium, Ce, white; oxygen, O, red. Bastnäsite, LnIIICO3F, is usually lacking in thorium and the heavy lanthanides beyond samarium and europium, and hence the extraction of cerium from it is quite direct. First, the bastnäsite is purified, using dilute hydrochloric acid to remove calcium carbonate impurities. The ore is then roasted in the air to oxidize it to the lanthanide oxides: while most of the lanthanides will be oxidized to the sesquioxides Ln2O3, cerium will be oxidized to the dioxide CeO2.
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In 1950, first experimental evidence for the existence of photophosphorylation in vivo was presented by Otto Kandler using intact Chlorella cells and interpreting his findings as light-dependent ATP formation. In 1954, Daniel I. Arnon et al. discovered photophosphorylation in vitro in isolated chloroplasts with the help of P32. Louis N.M. Duysens and Jan Amesz discovered that chlorophyll a will absorb one light, oxidize cytochrome f, chlorophyll a (and other pigments) will absorb another light, but will reduce this same oxidized cytochrome, stating the two light reactions are in series.
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Coinage metals, such as copper and silver, slowly corrode through use. A patina of green-blue copper carbonate forms on the surface of copper with exposure to the water and carbon dioxide in the air. Silver coins or cutlery that are exposed to high sulfur foods such as eggs or the low levels of sulfur species in the air develop a layer of black Silver sulfide. Gold and platinum are extremely difficult to oxidize under normal circumstances, and require exposure to a powerful chemical oxidizing agent such as aqua regia.
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The ruling would require the plant to reduce NOx emissions to no more than by 2023, necessitating the installation of Selective Catalytic Reduction (SCR) equipment. The SCRs would need to reduce NOx by about 15,000 tons per year. Along with the existing Low-NOx burners, the total reduction would be about 29,000 tons per year below 2008 levels. The SCRs would use a catalyst and ammonia to react with NOx to form diatomic nitrogen and water. SCRs would also increase sulfuric acid mist levels by causing SO2 to oxidize to SO3.
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This so-called "preg-robbing" carbon is washed away because it is significantly finer than the carbon recovery screens typically used to recover activated carbon. Pre-treatment options for refractory ores include: # Roasting # Bio-oxidation, such as Bacterial oxidation # Pressure oxidation # Albion process The refractory ore treatment processes may be preceded by concentration (usually sulfide flotation). Roasting is used to oxidize both the sulfur and organic carbon at high temperatures using air and/or oxygen. Bio-oxidation involves the use of bacteria that promote oxidation reactions in an aqueous environment.
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Dalfopristin is synthesized from pristinamycine IIa through achieving a stereoselective Michael-type addition of 2-diethylaminoethanethiol on the conjugated double bond of the dehydroproline ring . The first method found was using sodium periodate associated with ruthenium dioxide to directly oxidize the sulfur derivative into a sulfone. However, using hydrogen peroxide with sodium tungstate in a 2-phase medium produces an improved yield, and is therefore the method of choice for large scale production. The production of the dalfopristin portion of quinupristin/dalfopristin is achieved through purifying cocrystallization of the quinupristin and dalfopristin from acetone solutions.
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Thermophilic microbes have been found to be able to fix nitrogen at higher temperatures such as 92 °C. Nitrogen fixation may be especially prevalent in microbial mats and particulate material where biologically available levels of nitrogen are low, due to high microbe density and anaerobic environment allows the function of nitrogenase, a nitrogen fixing enzyme. Evidence have also been detected of assimilation, nitrification, denitrification, anamox, mineralization and dissimilatory nitrate reduction to ammonium. For example, sulfur oxidizing bacteria like Begiatoa species, perform denitrification and reduces nitrate to oxidize H2S.
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Like other alkanes, pentanes are largely unreactive at standard room temperature and conditions - however, with sufficient activation energy (e.g., an open flame), they readily oxidize to form carbon dioxide and water: :C5H12 \+ 8 O2 → 5 CO2 \+ 6 H2O + heat/energy Like other alkanes, pentanes undergo free radical chlorination: :C5H12 \+ Cl2 → C5H11Cl + HCl Such reactions are unselective; with n-pentane, the result is a mixture of the 1-, 2-, and 3-chloropentanes, as well as more highly chlorinated derivatives. Other radical halogenations can also occur. Pentane is a component of exhaled breath for some individuals.
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However, if oxygen is not present, fermentation of the pyruvate molecule will occur. In the presence of oxygen, when acetyl-CoA is produced, the molecule then enters the citric acid cycle (Krebs cycle) inside the mitochondrial matrix, and is oxidized to CO2 while at the same time reducing NAD to NADH. NADH can be used by the electron transport chain to create further ATP as part of oxidative phosphorylation. To fully oxidize the equivalent of one glucose molecule, two acetyl-CoA must be metabolized by the Krebs cycle.
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The Wittig reaction is a popular method for the synthesis of alkene from ketones and aldehydes. The Wittig reagent can generally tolerate carbonyl compounds containing several kinds of functional groups such as OH, OR, aromatic nitro and even ester groups . There can be a problem with sterically hindered ketones, where the reaction may be slow and give poor yields, particularly with stabilized ylides, and in such cases the Horner–Wadsworth–Emmons (HWE) reaction (using phosphonate esters) is preferred. Another reported limitation is the often labile nature of aldehydes which can oxidize, polymerize or decompose.
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It oxidizes succinate to fumarate and reduces ubiquinone. As this reaction releases less energy than the oxidation of NADH, complex II does not transport protons across the membrane and does not contribute to the proton gradient. In some eukaryotes, such as the parasitic worm Ascaris suum, an enzyme similar to complex II, fumarate reductase (menaquinol:fumarate oxidoreductase, or QFR), operates in reverse to oxidize ubiquinol and reduce fumarate. This allows the worm to survive in the anaerobic environment of the large intestine, carrying out anaerobic oxidative phosphorylation with fumarate as the electron acceptor.
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Many eukaryotic organisms have electron transport chains that differ from the much-studied mammalian enzymes described above. For example, plants have alternative NADH oxidases, which oxidize NADH in the cytosol rather than in the mitochondrial matrix, and pass these electrons to the ubiquinone pool. These enzymes do not transport protons, and, therefore, reduce ubiquinone without altering the electrochemical gradient across the inner membrane. Another example of a divergent electron transport chain is the alternative oxidase, which is found in plants, as well as some fungi, protists, and possibly some animals.
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Step 2 follows with an additional thiosulfate to subsequently form tetrathionate while reducing both hemes and leaving a typical cysteine residue. In the active site, the cysteine residue bound to the catalytic iron heme is essential for enzymatic activity, as the abolishment of this residue completely eliminated the enzyme's ability to both oxidize thiosulfate and reduce tetrathionate. In A. vinosum, although the process is reversible, the reaction to form two thiosulfate ions is much slower than the formation of tetrathionate despite the reduction of tetrathionate to thiosulfate having a potential of +198 mV.
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This demand occurs over some variable period of time depending on temperature, nutrient concentrations, and the enzymes available to indigenous microbial populations. The amount of oxygen required to completely oxidize the organic compounds to carbon dioxide and water through generations of microbial growth, death, decay, and cannibalism is total biochemical oxygen demand (total BOD). Total BOD is of more significance to food webs than to water quality. Dissolved oxygen depletion is most likely to become evident during the initial aquatic microbial population explosion in response to a large amount of organic material.
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Further in vitro studies of human DUOX1 (hDUOX11-593) and C. elegans DUOX1 (CeDUOX11-589) were made possible by expression and purification via a baculovirus system. Evaluation of these proteins demonstrated that the isolated hDUOX11-593 does not bind heme and has no intrinsic peroxidase activity. In contrast, CeDUOX11-589 binds heme covalently and exhibits a modest peroxidase activity, but does not oxidize bromide ion. Surprisingly, the heme appears to have two covalent links to the C. elegans protein despite the absence of a second conserved carboxyl group in the active site.
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Sulfate-reducing bacteria, oxidize the molecular hydrogen to produce hydrogen sulfide ions (HS−) and water: :4 H2 \+ SO42− -> HS− \+ 3 H2O + OH− The iron ions partly precipitate to form iron (II) sulfide. A reaction with water also occurs, producing iron hydroxide. :Fe2+ \+ HS− -> FeS + H+ :3 Fe2+ \+ 6 H2O -> 3 Fe(OH)2 \+ 6 H+ The net equation comes to: :4 Fe + SO42− \+ H+ \+ 3 H2O -> FeS + 3 Fe(OH)2 \+ OH− This form of corrosion by sulfate- reducing bacteria can, in this way, be far more harmful than anaerobic corrosion.
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Larger grains of nickel would reduce the contact area that ions can be conducted through, which would lower the cells efficiency. The anode is commonly the thickest and strongest layer in each individual cell, because it has the smallest polarization losses, and is often the layer that provides the mechanical support. Electrochemically speaking, the anode’s job is to use the oxygen ions that diffuse through the electrolyte to oxidize the hydrogen fuel. The oxidation reaction between the oxygen ions and the hydrogen produces heat as well as water and electricity.
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Using an under-rated, long, skinny, oxidized high impedance speaker cable will drastically reduce the damping properties of the entire audio system, which is why in many high-end audio systems, the amplifier is located as close to the speakers as possible. Oxidation: Aging cables exposed to air will oxidize, increasing impedance, causing intermittent connectivity and poor shielding, all of which will adversely effect the reproduced audio quality. Many plastic insulation materials composed of halogenated hydrocarbons decompose with age, releasing corrosive gas such as Chlorine, Fluorine, Oxygen etc. Quality cables are less prone to this.
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For space missions, gold is used because it is useful at reflecting light, which helps to detect celestial objects from far away and gold does not oxidize so it will not tarnish, unlike most other metals. Due to both benefits, the James Webb Space Telescope uses gold on its mirrors. NASA partnered with Epner Technology, a Brooklyn-based business that has been gold-plating for generations to develop the technology to gold plate the telescope's parts. This NASA technology transfer to Epner gave the company a reputation for durable gold coatings.
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This may be a preferred method to simple oral administration, because MAO is known to oxidize many drugs (especially the tryptamines such as DMT) and because this route translates the chemical directly to the brain, where most psychoactives act. The method is limited by excessive salivation washing the chemical down the throat. Also, many alkaloids have an unpleasant taste which makes them difficult to hold in the mouth. Tablets of psychoactive pharmaceuticals usually include bitter chemicals such as denatonium in order to discourage abuse and also to discourage children from eating them.
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The conjugate base of glyoxylic acid is known as glyoxylate and is the form that the compound exists in solution at neutral pH. Glyoxylate is the byproduct of the amidation process in biosynthesis of several amidated peptides. For the historical record, glyoxylic acid was prepared from oxalic acid electrosynthetically: in organic synthesis, lead dioxide cathodes were applied for preparing glyoxylic acid from oxalic acid in a sulfuric acid electrolyte. :380px Hot nitric acid can oxidize glyoxal to glyoxylic; however this reaction is highly exothermic and prone to thermal runaway.
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Possibly followed by quenching in water and drying. Another method is to oxidize the copper slightly in a gas flame and then to dip it into borax solution and let it dry. The surface of the borated copper is black when hot and turns to dark wine red on cooling. It is also possible to make a bright seal between copper and glass where it is possible to see the blank copper surface through the glass, but this gives less adherence than the seal with the red containing layer.
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As the carbon dioxide content increases over 20%, spray transfer GMAW becomes increasingly problematic, especially with smaller electrode diameters. Argon is also commonly mixed with other gases, oxygen, helium, hydrogen and nitrogen. The addition of up to 5% oxygen (like the higher concentrations of carbon dioxide mentioned above) can be helpful in welding stainless steel, however, in most applications carbon dioxide is preferred. Increased oxygen makes the shielding gas oxidize the electrode, which can lead to porosity in the deposit if the electrode does not contain sufficient deoxidizers.
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Sulfur and selenium tetrafluorides are molecular while TeF4 is a polymer. The hexafluorides are the result of direct fluorination of the elements (compare: other hexahalides of these elements do not even exist). They increase in reactivity with atomic number: SF6 is extremely inert, SeF6 is less noble (for example, reacts with ammonia at 200 °C (400 °F)), and TeF6 easily hydrolyzes to give an oxoacid. Oxygen's highest fluoride is oxygen difluoride, but fluorine can theoretically (as of 2012) oxidize it to a uniquely high oxidation state of +4 in the fluorocation: .
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A key feature is the use of a shrouded lance to inject oxygen through the bottom of the furnace, directly into the precious metals contained in the furnace, to oxidize base metals or other impurities as part of their removal as slag.J M Floyd, “Submerged bath smelting applied to the non-ferrous metal industry,” in: The Paul E. Queneau International Symposium, Extractive Metallurgy of Copper, Nickel and Cobalt, Volume I: Fundamental Aspects, Eds R G Reddy and R N Weizenbach (The Minerals, Metals and Materials Society: Warrendale, Pennsylvania, 1993), 473–488.
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Geopsychrobacter electrodiphilus is a species of bacteria, the type species of its genus. It is a psychrotolerant member of its family, capable of attaching to the anodes of sediment fuel cells and harvesting electricity by oxidation of organic compounds to carbon dioxide and transferring the electrons to the anode. In microbial communities, G. electrodiphilus could be similar to other Geobacteraceae. The community may ferment complex organic matter, thereby breaking up plant matter, for example; G. electrodiphilus would then oxidize the fermentation products (especially acetate) to carbon dioxide, whereby a terminal electron acceptor [e.g.
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A number of tests can be used to detect the presence of a peroxide in an ether; one is to use a combination of iron(II) sulfate and potassium thiocyanate. The peroxide is able to oxidize the Fe2+ ion to an Fe3+ ion, which then forms a deep-red coordination complex with the thiocyanate. Peroxides may be removed by washing with acidic iron(II) sulfate, filtering through alumina, or distilling from sodium/benzophenone. Alumina does not destroy the peroxides but merely traps them, and must be disposed of properly.
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Exposure to light is detrimental to the stability of aqueous solutions of psilocybin, and will cause it to rapidly oxidize—an important consideration when using it as an analytical standard. Osamu Shirota and colleagues reported a method for the large-scale synthesis of psilocybin without chromatographic purification in 2003. Starting with 4-hydroxyindole, they generated psilocybin from psilocin in 85% yield, a marked improvement over yields reported from previous syntheses. Purified psilocybin is a white, needle-like crystalline powder with a melting point between , and a slightly ammonia-like taste.
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The substrate specificity of 5-HEDH has been evaluated in a variety of intact cells and in crude microsome preparations isolated from cultured human blood monocytes differentiated into macrophages. These studies indicate that the enzyme efficiently oxidizes long chain unsaturated fatty acids possessing a hydroxy residue at carbon 5 and a trans double bound at carbon 6 to their corresponding 5-oxo products. It is therefore most efficient in metabolizing 5(S)-HETE to 5-oxo-ETE and, with somewhat lesser efficiency, in metabolizing other 5(S)-hydroxyl-6-trans unsaturated fatty acids such as 5(S)-hydroxy- eicosapentaenoic acid, 5(S)-hydroxy-eicosatrienoic acid, 5(S)-hydroxy- eicosadeinoic acid, 5(S)-hydroxy-eicosamonoenoic acid, 5(S)-hydroxy- octadecadienoic acid, 5(S),15(S)-dihydroxyeicosatetraenoic acid, and the 6-trans isomer of leukotriene B4 (which is a 5(S),12(S)-dihydroxyeicosatetraeonic acid) to their corresponding oxo analogs. 5-HEDH has relatively little ability to oxidize 5(S)-hydroxyl-tetradecadienoic acid, the R stereoisomer of 5(S)-HETE (5(R)-HETE), or a racemic mixture of 8-HETE, and does not oxidize 12(S)-HETE, 15(S)-HETE, leukotriene B4, a racemate mixture of 9-HETE, a racemate mixture of 11-HETE, or a 5(S)-hydroxy-6-trans 12 carbon dienoic fatty acid.
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One quality this explosive has, that PETN does not, is a positive oxygen balance, which means that ETN possesses more than enough oxygen in its structure to fully oxidize all of its carbon and hydrogen upon detonation. This can be seen in the schematic chemical equation below. :2 C4H6N4O12 -> 8 CO2 \+ 6 H2O + 4 N2 \+ 1 O2 Whereas PETN decomposes to: :2 C5H8N4O12 -> 6 CO2 \+ 8 H2O + 4 N2 \+ 4 CO The carbon monoxide (CO) still requires oxygen to complete oxidation to carbon dioxide (CO2). A detailed study of the decomposition chemistry of ETN has been recently elucidated.
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If there is an excess in the amount of tannins in the wine, winemakers can use various fining agents like albumin, casein and gelatin that can bind to tannins molecule and precipitate them out as sediments. As a wine ages, tannins will form long polymerized chains which come across to a taster as "softer" and less tannic. This process can be accelerated by exposing the wine to oxygen, which oxidize tannins to quinone-like compounds that are polymerization-prone. The winemaking technique of micro-oxygenation and decanting wine use oxygen to partially mimic the effect of aging on tannins.
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A carbon stripper may be needed at the solid outlet of the fluidized bed reducer to allow the unconverted char to be separated from the oxygen carriers. The char can be recycled back to the reducer for further conversion. Fig 5. Chemical looping three-reactor system for hydrogen production In a similar operating scheme to the CLR - MTS system given in Fig 4, chemical looping gasification (CLG) of solid fuels carried out in a co-current moving bed reducer to partially oxidize solid fuels into syngas can reach an appropriate H2/CO ratio for downstream processing.
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Leaves of Clairette vines Clairette blanche is a white wine grape variety most widely grown in the wine regions of Provence, Rhône and Languedoc in France. At the end of the 1990s, there were of Clairette blanche grown in France, although volumes are decreasing. Clairette blanche was often used to make vermouth, to which it is suited as it produces wine high in alcohol and low in acidity, and therefore yields wines that are sometimes described as "flabby" and which tend to oxidize easily. These problems have sometimes been partially overcome by blending it with high-acid varieties such as Piquepoul blanc.
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Two reactions take place during the measurement: Reaction 1 is a pretreatment of the sample performed by adding glucokinase to convert glucose to glucose 6-phosphate in the presence of adenosine triphosphate, pyruvate kinase, and phosphoenol pyruvate. The purpose of this step is to alter glucose, which is found in the blood sample, so that it can not react during reaction 2. Reaction 2 uses pyranose oxidase to oxidize the second hydroxyl of 1,5-AG, generating hydrogen peroxide. The amount of hydrogen peroxide is detected by colorimetry using peroxidase, and is in direct relationship to the serum 1,5-AG concentration.
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Methylcyclopentadienyl manganese tricarbonyl is used as an additive in unleaded gasoline to boost octane rating and reduce engine knocking. The manganese in this unusual organometallic compound is in the +1 oxidation state. Manganese(IV) oxide (manganese dioxide, MnO2) is used as a reagent in organic chemistry for the oxidation of benzylic alcohols (where the hydroxyl group is adjacent to an aromatic ring). Manganese dioxide has been used since antiquity to oxidize and neutralize the greenish tinge in glass from trace amounts of iron contamination. MnO2 is also used in the manufacture of oxygen and chlorine and in drying black paints.
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First of all, through the reaction of NO with HO2 radicals, •OH radicals are recycled, which oxidize methane molecules, meaning emissions can counter the effect of greenhouse gases. For instance, ship traffic emits a great amount of NOx which provides a source of NOx over the ocean. Then, photolysis of NO2 leads to the formation of ozone and the further formation of hydroxyl radicals (·OH) through ozone photolysis. Since the major sink of methane in the atmosphere is by reaction with •OH radicals, the NOx emissions from ship travel may lead to a net global cooling.
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Calculations indicate that copernicium may show the oxidation state +4, while mercury shows it in only one compound of disputed existence and zinc and cadmium do not show it at all. It has also been predicted to be more difficult to oxidize copernicium from its neutral state than the other group 12 elements, and indeed copernicium is expected to be the most noble metal on the periodic table. Solid copernicium is expected to be bound mostly by dispersion forces, like the noble gases; predictions on its band structure are varied, ranging from a noble metal to a semiconductor or even an insulator.
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Increased oxygen makes the shielding gas oxidize the electrode, which can lead to porosity in the deposit if the electrode does not contain sufficient deoxidizers. Excessive oxygen, especially when used in application for which it is not prescribed, can lead to brittleness in the heat affected zone. Argon-oxygen blends with 1–2% oxygen are used for austenitic stainless steel where argon-CO2 can not be used due to required low content of carbon in the weld; the weld has a tough oxide coating and may require cleaning. Hydrogen is used for welding of nickel and some stainless steels, especially thicker pieces.
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Titanium dioxide (TiO2) is also a leading candidate for nanoremediation and wastewater treatment, although as of 2010 it is reported to have not yet been expanded to full-scale commercialization. When exposed to ultraviolet light, such as in sunlight, titanium dioxide produces hydroxyl radicals, which are highly reactive and can oxidize contaminants. Hydroxyl radicals are used for water treatment in methods generally termed advanced oxidation processes. Because light is required for this reaction, TiO2 is not appropriate for underground in situ remediation, but it may be used for wastewater treatment or pump-and-treat groundwater remediation.
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This also allows for a classic use of Fétizon's reagent to form lactones from a primary diol. By oxidizing one of the alcohols to an aldehyde, the second alcohol equilibrates with the aldehyde to form a lactol which is reacted quickly with more Fétizon's reagent to trap the cyclic intermediate as a lactone. This method allows for the synthesis of seven-member lactones which are traditionally more challenging to synthesize. Fetizon's reagent oxidize lactols into lactones Treatment of a terminal diol with Fetizon's reagent can result in lactone formation Phenol functional groups can be oxidized to their respective quinone forms.
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Kombucha is now homebrewed globally, and also bottled and sold commercially by various companies. Kombucha is produced by fermenting sugared tea using a symbiotic culture of bacteria and yeast (SCOBY) commonly called a "mother" or "mushroom". The microbial populations in a SCOBY vary; the yeast component generally includes Saccharomyces cerevisiae, along with other species; the bacterial component almost always includes Gluconacetobacter xylinus to oxidize yeast-produced alcohols to acetic acid (and other acids). Although the SCOBY is commonly called "tea fungus" or "mushroom", it is actually "a symbiotic growth of acetic acid bacteria and osmophilic yeast species in a zoogleal mat ".
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A reaction catalyzed by a reductase enzyme Dehydrogenases oxidize a substrate by transferring hydrogen to an electron acceptor, common electron acceptors being NAD+ or FAD. This would be considered an oxidation of the substrate, in which the substrate either loses hydrogen atoms or gains an oxygen atom (from water). The name "dehydrogenase" is based on the idea that it facilitates the removal (de-) of hydrogen (-hydrogen-), and is an enzyme (-ase). Dehydrogenase reactions come most commonly in two forms: the transfer of a hydride and release of a proton (often with water as a second reactant), and the transfer of two hydrogens.
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Haypiles and compost piles may self-ignite because of heat produced by bacterial fermentation. Linseed oil and Danish oil in a confined space (such as a pile of oil-soaked rags left out in an uncovered container, especially if rags afterward used with anti-moisture solvent to clean up the oil) can oxidize, leading to a buildup of heat and thus ignition. Coal can ignite spontaneously when exposed to oxygen, which causes it to react and heat up when there is insufficient ventilation for cooling. Pyrite oxidation is often the cause of coal spontaneous ignition in old mine tailings.
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Manganese triacetate has been used as a one-electron oxidant. It can oxidize alkenes via addition of acetic acid to form lactones. :300px This process is thought to proceed via the formation of a •CH2CO2H radical intermediate, which then reacts with the alkene, followed by additional oxidation steps and finally ring closure. When the alkene is not symmetric, the major product depends on the nature of the alkene, and is consistent with initial formation of the more stable radical (among the two carbons of the alkene) followed by ring closure onto the more stable conformation of the intermediate.
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When reacted with enones, the carbon on the other side of the carbonyl reacts rather than the alkene portion, leading to α'-acetoxy enones. In this process, the carbon next to the carbonyl is oxidized by the manganese, followed by transfer of acetate from the manganese to it. It can similarly oxidize β-ketoesters at the α carbon, and this intermediate can react with various other structures, including halides and alkenes (see: manganese-mediated coupling reactions). One extension of this idea is the cyclization of the ketoester portion of the molecule with an alkene elsewhere in the same structure.
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Much of the tea grown in Kenya is processed using the crush, tear, curl method, making it suitable for use in blends popular in most black-tea markets, including India, Britain and North America. CTC tea has a homogeneous taste and a strong generic, bold "tea" flavor and is the base of most Indian tea blends as well as a significant portion of breakfast teas. Higher-quality Kenyan teas are processed using traditional methods (e.g. picking of the tender leaves and bud cyclically, these being allowed to dry and oxidize), and are often highly sought after "single origin" whole-leaf teas.
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There is some challenge to this because, to see the color of the metal, the smith must remove it from the fire—exposing it to air, which can rapidly oxidize it. So the smith might probe into the fire with a bit of steel wire, prodding lightly at the mating faces. When the end of the wire sticks on to the metal, it is at the right temperature (a small weld forms where the wire touches the mating face, so it sticks). The smith commonly places the metal in the fire so he can see it without letting surrounding air contact the surface.
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For example, many nuclear and cytosolic proteins can become disulfide-crosslinked during necrotic cell death. Similarly, a number of cytosolic proteins which have cysteine residues in proximity to each other that function as oxidation sensors or redox catalysts; when the reductive potential of the cell fails, they oxidize and trigger cellular response mechanisms. The virus Vaccinia also produces cytosolic proteins and peptides that have many disulfide bonds; although the reason for this is unknown presumably they have protective effects against intracellular proteolysis machinery. Disulfide bonds are also formed within and between protamines in the sperm chromatin of many mammalian species.
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Dissimilatory metal reducers are a diverse group of microorganisms, which is reflected in the factors that affect the different forms of metal reduction. The process of dissimilatory metal reduction occurs in the absence of oxygen (O2), but dissimilatory metal reducers include both obligate (strict) anaerobes, such as the family Geobacteraceae, and facultative anaerobes, such as Shewanella spp. As well, across the dissimilatory metal reducers species, various electron donors are used in the oxidative reaction that is coupled to metal reduction. For instance, some species are limited to small organic acids and hydrogen (H2), whereas others may oxidize aromatic compounds.
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Starting around 2.45 Ga and continuing to about 2.0 or 1.9 Ga, there was a dramatic rise in the oxygen content of the lower atmosphere, continents and oceans called the Great Oxygenation Event or Great Oxidation Event (GOE). Before the GOE, elements that can be in multiple oxidation states were restricted to the lowest state, and that limited the variety of minerals they could form. In older sediments, the minerals siderite (FeCO3), uraninite (UO2) and pyrite (FeS2) are commonly found. These oxidize rapidly when exposed to an atmosphere with oxygen, yet this did not occur even after extensive weathering and transport.
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The filtered concentrate slurry is piped to the smelter, where it is dried, and then injected along with oxygen into a flash smelting furnace to oxidize the iron and sulfur. The oxidized iron is skimmed off, while the sulfur dioxide gas is captured and sent to an on-site acid plant for conversion to valuable sulfuric acid – a million tons of it each year. Left behind is a molten copper sulfide called matte. The 70-percent-copper matte is water-quenched to form a sand-like solid, then injected, with oxygen, into a flash-converting furnace that produces molten, 98.6-percent-pure copper.
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Hummingbirds can use newly- ingested sugars to fuel hovering flight within 30–45 minutes of consumption. These data suggest that hummingbirds are able to oxidize sugar in flight muscles at rates high enough to satisfy their extreme metabolic demands. A 2017 review indicated that hummingbirds have in their flight muscles a mechanism for "direct oxidation" of sugars into maximal ATP yield to support their high metabolic rate for hovering, foraging at altitude, and migrating. By relying on newly-ingested sugars to fuel flight, hummingbirds can reserve their limited fat stores to sustain their overnight fasting or to power migratory flights.
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Strains of V. paradoxus have also been identified that can degrade N-acyl homoserine-lactones (AHL), microbial signalling molecules involved in quorum sensing. It is hypothesized that this ability could provide a host plant protection from pathogenic infection, with the impact of quorum quenching to reduce virulence in pathogenic strains present. V. paradoxus is involved in cycling numerous inorganic elements including arsenic, sulfur, manganese and rare earth elements in a range of soil, freshwater and geological environments. In the case of arsenic, V. paradoxus is believed to oxidize As (III) to As (V) as a detoxification mechanism.
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Calyptogena magnifica is assumed to burrow and it is thought the divided foot may be specially adapted for insertion into cracks in hard substrates or among mussels (Bathymodiolus thermophilus). The animal can move around on the sea floor with its muscular foot and usually takes up a vertical position rather than lying flat. Calyptogena magnifica is specially adapted to life round hydrothermal vents by the chemosymbiotic bacteria it harbours in its gills which oxidize hydrogen sulfide seeping from the vents. The clam absorbs nutrients produced by these bacteria rather than photosynthetically derived products and no longer has guts.
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Service trenches in pavements after construction have been said to reduce the life of the pavement by 50%, mainly due to the lack of compaction in the trench, and also because of water intrusion through improperly sealed joints. Environmental factors include heat and cold, the presence of water in the subbase or subgrade soil underlying the pavement, and frost heaves. High temperatures soften the asphalt binder, allowing heavy tire loads to deform the pavement into ruts. Paradoxically, high heat and strong sunlight also cause the asphalt to oxidize, becoming stiffer and less resilient, leading to crack formation.
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Research has shown that chromium(III) may in fact cause irreversible inhibition of PTP1B. It is thought that Cr(III) is converted to Cr(VI) or Cr(V) (through the action of oxidoreductases) which then oxidize the thiol of the cysteine residue on PTP1B to sulfenic acid, consequently rendering it unable to attack the phosphate group on phosphotyrosine. However, this is only a plausible mechanism, and no direct evidence has been shown to support this hypothesis. When the signal cascade is turned off, holochromodulin is eliminated in urine since the formation constant is too large to remove Cr(III) directly.
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This reduced form of Cr(II) is shown to react with H2O2 to generate radical species which in turn oxidize DNA base pairs. With this knowledge in mind, the researchers administered ten women with 400 μg of chromium(III) picolinate a day for an eight-week period. By measuring the amount of an oxidized DNA base pair, 5-hydroxymethyl uracil using antibody titers, the group could infer the amount of DNA base pair oxidation occurring in direct relation to chromium(III) picolinate. The results of the study suggested that chromium(III) picolinate itself does not cause significant chromosomal damage in vivo.
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A study of F. acidarmanus found that cytoplasmic pH was maintained ~5.6 while the environmental pH ranged from ~0-1.2. Variations in the tetraether lipids of the family Ferroplasmaceae are used for chemotaxonomic identification at the genus and species level because many members possess identical 16S rRNA sequences. Members of the genus Ferroplasma are chemomixotrophs that can oxidize ferrous iron to acquire energy, but despite evidence of carbon fixation, lab cultures often require an organic carbon source such as yeast extract for growth. In the absence of iron, some lab-grown strains have been capable of chemoorganotrophic growth.
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Disorders of fatty acid metabolism can be described in terms of, for example, hypertriglyceridemia (too high level of triglycerides), or other types of hyperlipidemia. These may be familial or acquired. Familial types of disorders of fatty acid metabolism are generally classified as inborn errors of lipid metabolism. These disorders may be described as fatty oxidation disorders or as a lipid storage disorders, and are any one of several inborn errors of metabolism that result from enzyme defects affecting the ability of the body to oxidize fatty acids in order to produce energy within muscles, liver, and other cell types.
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In biochemical systems, the process of demethylation is catalyzed by demethylases. These enzymes oxidize N-methyl groups, which occur in histones and some forms of DNA: :R2N-CH3 \+ O → R2N-H + CH2O One such oxidative enzyme family is the cytochrome P450. Alpha-ketoglutarate-dependent hydroxylases are active for demethylation of DNA, operating by similar pathway. These reactions exploit the weak C-H bond adjacent to amines. The conversion of 5-methylcytosine to 5-hydroxymethylcytosine by TET enzyme plus a-ketoglutarate & Fe(II) In particular, 5-methylcytosines in DNA can be demethylated by TET enzymes as illustrated in the Figure.
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In 1998, Metcalf and Wolfe enriched for and isolated a P. stutzeri strain WM88 that could oxidize reduced phosphorus compounds, such as phosphite and hypophosphite, to phosphate. To enrich for a hypophosphite-utilizing organism, a 0.4% glucose-MOPS medium containing 0.5 mM hypophosphite was used as the sole phosphorus source with inoculum from a variety of soil and water environments. Specifically, strain WM88 can use phosphite as its sole phosphorus source when grown in succinate- MOPS medium. When grown anaerobically, the researchers showed P. stutzeri is unable to perform hypophosphite oxidation with nitrate as its electron acceptor.
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Comammox (COMplete AMMonia OXidiser) is the name attributed to an organism that can convert ammonia into nitrite and then into nitrate through the process of nitrification. Nitrification has traditionally thought to be a two- step process, where ammonia-oxidizing bacteria and archaea oxidize ammonia to nitrite and then nitrite-oxidizing bacteria convert to nitrate. Complete conversion of ammonia into nitrate by a single microorganism was first predicted in 2006. Approximately ten years later, the presence of microorganisms that could carry out both conversion processes was discovered within the genus Nitrospira, and the nitrogen cycle was updated.
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Fungi have been shown to be viable organisms to conduct bioremediation and have been used to aid in the decontamination of a number of pollutants including polycyclic aromatic hydrocarbons (PAHs), pesticides, synthetic dyes, chlorophenols, explosives, crude oil, and many others. While fungi can breakdown many of these contaminants intracellularly, they also secrete numerous oxidative exoenzymes that work extracellularly. One critical aspect of fungi in regards to bioremediation is that they secrete these oxidative exoenzymes from their ever elongating hyphal tips. Laccases are an important oxidative enzyme that fungi secrete and use oxygen to oxidize many pollutants.
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The metabolism of PPFMs is unusual because, as their name suggests, they are able to utilize C1 compounds such as formaldehyde, methanol and methylamine. PPFM bacteria can undergo methylotrophy, a process in which the bacteria oxidize methanol with the help of the enzymes methanol dehydrogenase (MDH) and pyrroloquinoline quinone (PQQ)-linked protein. In dense and diverse communities like those found in the phyllosphere and rhizosphere, this enables them to utilize nutrients other bacteria cannot, enhancing their competitive ability. In certain environments there are limited concentrations of elements such as carbon and phosphate in a usable form.
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The ability for CS to deposit materials that are phase-sensitive or temperature-sensitive has positioned the technique to prepare coatings not possible with other thermal spray techniques. CS can generally be used to produce coatings of a wide variety of metals, alloys, and metal-based composites, including those materials that have an exceptionally high melting temperatures (e.g. tantalum, niobium, superalloys). The process is also valuable for depositing materials that are extremely sensitive to the presence of oxygen and will readily oxidize at modest elevated temperatures – a result which is deleterious to the performance of these materials.
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Most of the subseafloor is anoxic because oxygen is removed by aerobic microorganisms within the first few centimeters of the sediment. Below the oxygen replete seafloor, methanogens produce methane that is either used by other organisms or becomes trapped in gas hydrates. These other organisms which utilize methane for energy are known as methanotrophs (methane-eating), and are the main reason why little methane generated at depth reaches the sea surface. Consortia of Archaea and Bacteria have been found to oxidize methane via Anaerobic Oxidation of Methane (AOM); the organisms responsible for this are Anaerobic Methanotrophic Archaea (ANME) and Sulfate-Reducing Bacteria (SRB).
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Sodium glucuronate can be produced by the direct oxidation of starch with concentrated nitric acid. In this preparation the low availability of water keeps the starch polymers from hydrolyzing and only oxidizes the free hydroxyls, in much the same way that nitrogen dioxide would oxidize the starch. Once this reaction is complete, and the starch/nitric acid mix turns clear (after giving off nitrogen dioxide gas), the solution can be diluted, and hydrolyzed with another mineral acid. Then the oxidation is slowly quenched with sodium hydroxide (or sodium bicarbonate), forming sodium glucuronate, which can be crystallized out of solution.
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Chronic high doses of β-carotene supplementation increases the probability of lung cancer in smokers. The effect is specific to supplementation dose as no lung damage has been detected in those who are exposed to cigarette smoke and who ingest a physiologic dose of β-carotene (6 mg), in contrast to high pharmacologic dose (30 mg). Therefore, the oncology from β-carotene is based on both cigarette smoke and high daily doses of β-carotene. Increases in lung cancer may be due to the tendency of β-carotene to oxidize, and may hasten oxidation more than other food colors such as annatto.
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Combinations of iron, aluminium, silicon and manganese make brass wear- and tear-resistant. Notably, the addition of as little as 1% iron to a brass alloy will result in an alloy with a noticeable magnetic attraction. Binary phase diagram Brass will corrode in the presence of moisture, chlorides, acetates, ammonia, and certain acids. This often happens when the copper reacts with sulfur to form a brown and eventually black surface layer of copper sulfide which, if regularly exposed to slightly acidic water such as urban rainwater, can then oxidize in air to form a patina of green-blue copper sulfate.
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In Finland it was sold under trade name Fegabit. Potassium chlorate can react with sulfuric acid to form a highly reactive solution of chloric acid and potassium sulfate: :2 KClO3 \+ H2SO4 → 2 HClO3 \+ K2SO4 The solution so produced is sufficiently reactive that it spontaneously ignites if combustible material (sugar, paper, etc.) is present. In schools, molten potassium chlorate is used in the dramatic screaming jelly babies, Gummy bear, Haribo, and Trolli candy demonstration where the candy is dropped into the molten salt. In chemical labs it is used to oxidize HCl and release small amounts of gaseous chlorine.
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Sodium and lithium are frequently used, as they form inexpensive, soluble salts. If an acid is used as the electrolyte, the cation is H+, and there is no competitor for the H+ created by disassociating water. The most commonly used anion is sulfate (), as it is very difficult to oxidize, with the standard potential for oxidation of this ion to the peroxydisulfate ion being +2.010 volts. Strong acids such as sulfuric acid (H2SO4), and strong bases such as potassium hydroxide (KOH), and sodium hydroxide (NaOH) are frequently used as electrolytes due to their strong conducting abilities.
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Sodium cyanide is used mainly to extract gold and other precious metals in mining industry. This application exploits the high affinity of gold(I) for cyanide, which induces gold metal to oxidize and dissolve in the presence of air (oxygen) and water, producing the salt sodium gold cyanide (or gold sodium cyanide) and sodium hydroxide: :4 Au + 8 NaCN + O2 \+ 2 H2O → 4 Na[Au(CN)2] + 4 NaOH A similar process uses potassium cyanide (KCN, a close relative of sodium cyanide) to produce potassium gold cyanide (KAu(CN)2). Few other methods exist for this extraction process.
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The selenium cycle is a biological cycle of selenium similar to the cycles of carbon, nitrogen, and sulfur. Within the cycle, there are organisms which reduce the most oxidized form of the element and different organisms complete the cycle by oxidizing the reduced element to the initial state. In the selenium cycle it has been found that bacteria, fungi, and plants, especially species of Astragalus, metabolize the most oxidized forms of selenium, selenate or selenite, to selenide. It is also thought that microorganisms may be able to oxidize selenium of valence zero to selenium of valence +6.
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Organic residues from these extinction boundaries indicate that the oceans were anoxic (oxygen-depleted) and had species of shallow plankton that metabolized . The formation of may have been initiated by massive volcanic eruptions, which emitted carbon dioxide and methane into the atmosphere, which warmed the oceans, lowering their capacity to absorb oxygen that would otherwise oxidize . The increased levels of hydrogen sulfide could have killed oxygen-generating plants as well as depleted the ozone layer, causing further stress. Small blooms have been detected in modern times in the Dead Sea and in the Atlantic ocean off the coast of Namibia.
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Fugate- Wilcox concrete sculptures typically consist of flat slabs of concrete in the elemental polygonal shapes so often favored by minimalist artists. Fugate- Wilcox peppers the exposed surfaces of the still-wet concrete with metallic powder or other substances likely to oxidize or otherwise chemically change with the passage of time, thus changing the surface colors.[Seeman, Helene."Art at Gateway Center, 2nd Annual Sculpture Exhibit," Newark, Cat, 7/1991, illust.] The artist's Weathering Triangle outdoor sculpture in New York City was meant to feature the changing colors brought about by chemical reactions over time; however, Smithsonian photos Smithsonian (ref# IAS 87870227), Smithsonian.
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One of the first chemicals to be produced in large amounts through industrial processes was sulfuric acid. In 1736, the pharmacist Joshua Ward developed a process for its production that involved heating saltpeter, allowing the sulfur to oxidize and combine with water. It was the first practical production of sulphuric acid on a large scale. John Roebuck and Samuel Garbett were the first to establish a large-scale factory in Prestonpans, Scotland, in 1749, which used leaden condensing chambers for the manufacture of sulfuric acid. Charles Tennant's St. Rollox Chemical Works in 1831, then the biggest chemical enterprise in the world.
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It has been suggested to be loosely related to gravitational influence of both moons, somewhat similar to the creation of tides on Earth. The Martian atmosphere is an oxidizing atmosphere. The photochemical reactions in the atmosphere tend to oxidize the organic species and turn them into carbon dioxide or carbon monoxide. Although the most sensitive methane probe on the recently launched ExoMars Trace Gas Orbiter failed to find methane in the atmosphere over the whole of Mars, several previous missions and ground-based telescope detected unexpected levels of methane in the Martian atmosphere, which may even be a biosignature for life on Mars.
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If fresh water was allowed to run through the tailings it would constantly dissolve and oxidize the rock's sulfides. Ridgeway chose to keep the tailings in stagnant water that has already had a chance to fully saturate with sulfides. The tailing impoundment was created by saturating the tailings with water, mining nearby saprolites and clay, sending the saprolites and clay through the ore mills and pouring them over the existing pile of tailings to create a layer over it. The impoundment was then graded to give it steep sides and a flat top and grass was planted on it to prevent erosion.
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Nigori sake is generally the sweetest of all sake, with a fruity nose and a mild flavor, making a great drink to complement spicy foods or as a dessert wine. Before serving, the bottle is shaken properly to mix the sediment with the sake, to obtain the full range of flavor and its signature look. It is advised that it be served well-chilled, storing it in an ice bucket to keep it from warming up between servings. It is recommended, as with most sake, to consume the entire bottle once opened before it begins to oxidize, altering its flavor.
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The suggestion of Winogradsky was confirmed nearly 90 years later, when hydrothermal ocean vents were predicted to exist in the 1970s. The hot springs and strange creatures were discovered by Alvin, the world's first deep-sea submersible, in 1977 at the Galapagos Rift. At about the same time, then-graduate student Colleen Cavanaugh proposed chemosynthetic bacteria that oxidize sulfides or elemental sulfur as a mechanism by which tube worms could survive near hydrothermal vents. Cavanaugh later managed to confirm that this was indeed the method by which the worms could thrive, and is generally credited with the discovery of chemosynthesis.
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It is an increasingly rare and expensive variety of tea. The process for making yellow tea is similar to that of green but with an added step of encasing and steaming the tea. This allows the tea to oxidize at a slow rate for a brief period before the tea is heated fully to denature the oxidizing enzymes, producing a far more mellow taste than is found in most green teas; this also gives the leaves a slightly yellow coloring during the drying process. Yellow tea is often placed in the same category with green tea due to its light oxidation.
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Dichromic acid, H2Cr2O7 is the fully protonated form of the dichromate ion and also can be seen as the product of adding chromium trioxide to molecular chromic acid. Dichromic acid will behave the same exact way when reacting with an aldehyde or ketone. The caveat to this statement, however, is that a secondary ketone will be oxidized no further than a ketone and dichromic acid will oxidize the aldehyde only. The aldehyde will be oxidized to a ketone for the first step of the mechanism and oxidized again to a carboxylic acid, contingent on no significant steric hindrance impeding this reaction.
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The White–Chen catalyst is an Iron-based coordination complex named after Professor M. Christina White and her graduate student Mark S. Chen. The catalyst is used along with hydrogen peroxide and acetic acid additive to oxidize aliphatic sp3 C-H bonds in organic synthesis. The catalyst is the first to allow for preparative and predictable aliphatic C–H oxidations over a broad range of organic substrates. Oxidations with the catalyst have proven to be remarkably predictable based on sterics, electronics, and stereoelectronics allowing for aliphatic C–H bonds to be thought of as a functional group in the streamlining of organic synthesis.
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Indirect calorimetry measures O2 consumption and CO2 production. On the assumption that all the oxygen is used to oxidize degradable fuels and all the CO2, thereby evolved is recovered, it is possible to calculate the total amount of energy produced. It should be clear that “energy production” means conversion of the chemical free-energy of nutrients into the chemical energy of ATP plus loss of some energy during the oxidation process. Respiratory indirect calorimetry, or indirect calorimetry (IC) as it is known by most authors, is a noninvasive and highly accurate method of metabolic rate which has an error rate lower than 1%.
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In such a case, the current is said to be diffusion limited. As the analyte is reduced at the working electrode, the concentration of the analyte in the whole solution will very slowly decrease; this depends on the size of the working electrode compared to the volume of the solution. What happens if some other species which reacts with the analyte (the titrant) is added? (For instance, chromate ions can be added to oxidize lead ions.) After a small quantity of the titrant (chromate) is added, the concentration of the analyte (lead) has decreased due to the reaction with chromate.
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The strong oxidative potential of the positive holes oxidizes water to create hydroxyl radicals. It can also oxidize oxygen or organic materials directly. Hence, in addition to its use as a pigment, titanium dioxide can be added to paints, cements, windows, tiles, or other products for its sterilizing, deodorizing, and anti- fouling properties, and is used as a hydrolysis catalyst. It is also used in dye-sensitized solar cells, which are a type of chemical solar cell (also known as a Graetzel cell). The photocatalytic properties of nanosized titanium dioxide were discovered by Akira Fujishima in 1967 and published in 1972.
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Illustrative is the oxidation of the following diol to a carboxylic acid: :450px Oxidation of epoxy alcohols also occurs without degradation of the epoxide ring: :450px Under milder conditions, oxidative reaction yields aldehydes instead. RuO4 readily converts secondary alcohols into ketones. Although similar results can be achieved with other cheaper oxidants such as PCC- or DMSO-based oxidants, RuO4 is ideal when a very vigorous oxidant is needed, but mild conditions must be maintained. It is used in organic synthesis to oxidize internal alkynes to 1,2-diketones, and terminal alkynes along with primary alcohols to carboxylic acids.
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Theoretical oxygen demand (ThOD) is the calculated amount of oxygen required to oxidize a compound to its final oxidation products. However, there are some differences between standard methods that can influence the results obtained: for example, some calculations assume that nitrogen released from organic compounds is generated as ammonia, whereas others allow for ammonia oxidation to nitrate. Therefore, in expressing results, the calculation assumptions should always be stated. In order to determine the ThOD for glycine (CH2(NH2)COOH) using the following assumptions: #In the first step, the organic carbon and nitrogen are converted to carbon dioxide (CO2) and ammonia (NH3), respectively.
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A polished and chemically etched piece of an iron meteorite, believed to be similar in composition to the Earth's metallic core, showing individual crystals of the iron-nickel alloy (Widmanstatten pattern). Metallic or native iron is rarely found on the surface of the Earth because it tends to oxidize. However, both the Earth's inner and outer core, that account for 35% of the mass of the whole Earth, are believed to consist largely of an iron alloy, possibly with nickel. Electric currents in the liquid outer core are believed to be the origin of the Earth's magnetic field.
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This activated state of heme is called compound I. In this state oxygen could be described as an oxyferryl species. It's thought that the pi-cation porphyrin radical undergoes reactivity at the methine bridges connecting the four rings. Compound I reduction in the presence of halides X− proceeds as follows: : [Fe(IV)=O...Por•+] + X− → [Fe(III)...Por] + HOX Thus, compound I is reduced back to the enzyme's resting state, and halide ions bound in the distal cavity are oxidized to potent oxidizing agents. However, there is a second cycle wherein compound I can proceed via two one-electron reduction steps to oxidize arbitrary substrates to their radical forms.
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CYP4F3A and/or CYP43FB also omega oxidize arachidonic acid to 20-Hydroxyeicosatetraenoic acid (20-HETE) as well as epoxyeicosatrienoic acids (EETs) to 20-hydroxy-EETs. 20-HETE regulates blood flow, vascularization, blood pressure, and kidney tubule absorption of ions in rodents and possibly humans; it has also been proposed to be involved in regulating the growth of various types of human cancers (see 20-Hydroxyeicosatetraenoic acid#cancer). EETS have a similar set of regulatory functions but often act in a manner opposite to 20-HETE (see epoxyeicosatrienoic acid#cancer); since, however, the activities of the 20-HEETs have not been well-defined, the function of EET omega oxidation is unclear.
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However, later experiments found no evidence for mendelevium(I) and found that mendelevium behaved like divalent elements when reduced, not like the monovalent alkali metals. Nevertheless, the Russian team conducted further studies on the thermodynamics of cocrystallizing mendelevium with alkali metal chlorides, and concluded that mendelevium(I) had formed and could form mixed crystals with divalent elements, thus cocrystallizing with them. The status of the +1 oxidation state is still tentative. Although E°(Md4+→Md3+) was predicted in 1975 to be +5.4 V, suggesting that mendelevium(III) could be oxidized to mendelevium(IV), 1967 experiments with the strong oxidizing agent sodium bismuthate were unable to oxidize mendelevium(III) to mendelevium(IV).
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When combined with added sugar or corn syrup, bright colors give the subconscious impression of healthy, ripe fruit, full of antioxidants and phytochemicals. One variation is packaging which obscures the true color of the foods contained within, such as red mesh bags containing yellow oranges or grapefruit, which then appear to be a ripe orange or red. Regularly stirring minced meat on sale at a deli can also make the meat on the surface stay red, causing it to appear fresh, while it would quickly oxidize and brown, showing its true age, if left unstirred. Some sodas are also sold in colored bottles, when the actual product is clear.
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Mulder, Scully, and Trondheim eventually begin to age unnaturally. Scully develops a theory that the Ardent is sailing near a metallic object beneath the ocean, and that it has caused free radicals to rapidly oxidize their bodies and age them. When Mulder notices that the ship's sewage pipe is the only one not corroded through, the agents realize that something from the ocean contaminated the Ardent's potable water and led to the aging; Olafsson and his men remained unaffected due to their consumption of recycled water from the sewage system. Desperate to survive, Trondheim kills Olafsson after he reveals the secret, and sets out to keep the water for himself.
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In Chinese, semi-oxidized teas are collectively grouped as blue tea (青茶, literally: blue-green tea; also, celadon tea, for the pottery), while the term oolong is used specifically as a name for certain semi-oxidized teas. Common wisdom about lightly oxidized teas in Taiwan (a large producer of Oolong) is that too little oxidation upsets the stomach of some consumers. Even so, some producers attempt to minimize oxidation in order to produce a specific taste or allow the tea leaves to be easily rolled into the spherical or half-sphere form demanded by buyers in the market. ; Black tea: The tea leaves are allowed to completely oxidize.
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The inability of Fétizon's reagent to oxidize tertiary alcohols makes it extremely useful in the monooxidation of a [1,2] diol in which one of the alcohols is tertiary while avoiding cleavage of the carbon-carbon bond. Fetizon's reagent oxidizes secondary alcohols selectively in the presence of tertiary alcohols The mildness and structural sensitivity of the reagent also makes this reagent ideal for the monooxidation of a symmetric diol. Fetizon's reagent is capable of monooxidizing a symmetric diol Lactols are extremely sensitive to Fétizon's reagent, being oxidized very quickly to a lactone functionality. This allows for the selective oxidation of lactols in the presence of other alcohols.
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While tertiary alcohols are typically not affected by Fétizon's reagent, tertiary propargylic alcohols have been shown to oxidize under these conditions and results in the fragmentation of the alcohol with an alkyne leaving group. A tertiary propargylic alcohol is fragmented upon treatment with Fetizon's reagent Halohydrins that possess a trans stereochemistry have been demonstrated to form epoxides and transposed products in the presence of Fétizon's reagent. Halohydrins possessing a cis- stereochemistry seem to perform a typical Fétizon's oxidation to a ketone. Trans-halohydrins can transpose or form epoxides upon treatment with Fetizon's reagent [1,3] diols have a tendency to eliminate water following the monooxidation by Fétizon's reagent to form an enone.
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An exponential increase in C/N ratios is observed with increasing water depth—with C/N ratios reaching 10 at intermediate water depths of about 1000 meters, and up to 15 in the deep ocean (~ >2500 meters) . This elevated C/N signature is preserved in the sediment, until another form of diagenesis, post-depositional diagenesis, alters its C/N signature once again. Post- depositional diagenesis occurs in organic-carbon-poor marine sediments where bacteria are able to oxidize organic matter in aerobic conditions as an energy source. The oxidation reaction proceeds as follows: CH2O + H2O → CO2 \+ 4H+ \+ 4e−, with a standard free energy of –27.4 kJ mol−1 (half reaction).
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On the other hand, the cable bacteria belong to the family Desulfobulbaceae of the Deltaproteobacteria and are currently represented by two candidate Genera, "Candidatus Electronema" and "Candidatus Electrothrix". Anaerobic SOB (AnSOB) are mainly neutrophilic/mesophilic photosynthetic autotrophs, which obtain energy from sunlight but use reduced sulfur compounds instead of water as electron donors for photosynthesis. AnSOB include some purple sulfur bacteria (Chromatiaceae) such as Allochromatium, and green sulfur bacteria (Chlorobiaceae), as well as the purple non-sulfur bacteria (Rhodospirillaceae) and some Cyanobacteria. The AnSOB Cyanobacteria are only able to oxidize sulfide to elemental sulfur and have been identified as Oscillatoria, Lyngbya, Aphanotece, Microcoleus, and Phormidium.
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Scheme of a Lurgi gasifier During gasification, the coal is blown through with oxygen and steam (water vapor) while also being heated (and in some cases pressurized). If the coal is heated by external heat sources the process is called "allothermal", while "autothermal" process assumes heating of the coal via exothermal chemical reactions occurring inside the gasifier itself. It is essential that the oxidizer supplied is insufficient for complete oxidizing (combustion) of the fuel. During the reactions mentioned, oxygen and water molecules oxidize the coal and produce a gaseous mixture of carbon dioxide (CO2), carbon monoxide (CO), water vapour (H2O), and molecular hydrogen (H2).
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Nitrite oxidoreductase (NOR or NXR) is an enzyme involved in nitrification. It is the last step in the process of aerobic ammonia oxidation, which is carried out by two groups of nitrifying bacteria: ammonia oxidizers such as Nitrosospira, Nitrosomonas and Nitrosococcus convert ammonia to nitrite, while nitrite oxidizers such as Nitrobacter and Nitrospira oxidize nitrite to nitrate. The enzyme is bound to the inner cytoplasmic surface of the bacterial membrane and contains multiple subunits, iron-sulfur centers and a molybdenum cofactor. The enzyme is relatively abundant, making up 10-30% of the total protein in these bacteria and forms densely packed structures on the membrane surface.
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Microbial electrochemistry utilizes bacteria that are able to transfer electrons to the anode of an electrochemical cell. Called “anode-respiring bacteria,” they are able to oxidize organic molecules and create an electrical current that can be used to generate electrical power, hydrogen gas, hydrogen peroxide, or other reduced materials, depending on conditions at the cathode of the electrochemical cell. Working with Center colleagues Dr. César Torres and Dr. Sudeep Popat, Rittmann is advancing the fundamental science and technology bases for microbial electrochemistry, with the ultimate goal of using the technology to capture the energy in organic waste streams as valuable energy or chemical outputs.
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Ozone is used in industrial settings to sterilize water and air, as well as a disinfectant for surfaces. It has the benefit of being able to oxidize most organic matter. On the other hand, it is a toxic and unstable gas that must be produced on-site, so it is not practical to use in many settings. Ozone offers many advantages as a sterilant gas; ozone is a very efficient sterilant because of its strong oxidizing properties (E=2.076 vs SHE) capable of destroying a wide range of pathogens, including prions, without the need for handling hazardous chemicals since the ozone is generated within the sterilizer from medical-grade oxygen.
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After-rust is a form of rust which sometimes develops on a non-ferrous metal surface when that surface has been finished, deburred, or cleaned with a carbon steel brush or steel wool. It is caused by microscopic deposits of the steel which become embedded in the metal surface and which over time begin to oxidize. This oxidation causes the surface to become dull and may impart a brown color to it. After-rust can be avoided by cleaning such surfaces only with non-ferrous brushes/ wools including rustless bronze, aluminum, and stainless steel wool and nonferrous wools such as those made of brass.
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The ulvöspinel component tends to oxidize to magnetite plus ilmenite during subsolidus cooling of the host rocks, and the ilmenite so produced may form apparent exsolution (trellis type) laminae in magnetite. The texture was once interpreted as indicating solid solution between ilmenite and magnetite, until the oxidation reaction and resultant textures were reproduced in laboratory experiments first described by Buddington and Lindsley (1964, Journal of Petrology 5, p. 310-357). The results are important to plate tectonics because magnetite is an important recorder of rock magnetism. Ulvöspinel was first described by Fredrik Mogensen (1904-1978) from a dolerite layered intrusion in the Ulvö Islands, Ångermanland, Sweden in 1943.
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In addition to being relatively inexpensive, glass is chemically inert. It does not oxidize, nor does it change or interact with the composition of printing inks, especially yellows and whites, which can turn green or gray in contact with metal plates.Lidh, W. (1986) “Prints from Glass”, Introduction. Western Carolina University, Cullowhee, NC, According to Claire Van Vliet of Janus Press, intaglio vitreographs also have an advantage over metal in that the glass plate wipes cleanly in non-image areas, allowing bright white to coincide with “black that is velvety as a mezzotint” in the finished print.McLean, G. (1999) “In Black and White: Landscape Prints by Claire Van Vliet”, page 61.
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Dr. Louie's research aims to mediate these transitions via metal catalyzed reactions, mainly involving nickel catalysis. Dr. Louie and her team focuses on nickel-based systems not only because it is much less expensive than the more widely used palladium and platinum, but also because it offers a wider range of chemical activity, such as nickel, being a more electropositive transition metal which allows it to undergo oxidative addition readily; oxidize Nickel and lessens the electron density around the atom itself.6 This allows for the cross-coupling of electrophiles to occur which is pivotal in the formation of carbocycles and heterocycles.Thakur, Ashish, and Janis Louie.
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Since then, other oxidizing agents such as ceric sulphate, potassium iodate, and potassium dichromate have been used to determine COD. Of these, potassium dichromate (K2Cr2O7) has been shown to be the most effective: it is relatively cheap, easy to purify, and is able to nearly completely oxidize almost all organic compounds. In these methods, a fixed volume with a known excess amount of the oxidant is added to a sample of the solution being analyzed. After a refluxing digestion step, the initial concentration of organic substances in the sample is calculated from a titrimetric or spectrophotometric determination of the oxidant still remaining in the sample.
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Utilization of alternate electron acceptors by this organism depends on the electron donor present. For instance, it will utilize nitrate (NO3) and Mn(IV) as alternative electron acceptors when lactate is being used as the electron donor. G. fermentans, though it shares similar reduction processes as the other DIRB, displays metabolic characteristics that set it apart from other iron reducers. In the process of respiration, this organism is capable of complete oxidation of the before-mentioned organic acids to CO2 using Fe(III), whereas other iron-reducing species of the families Shewanella or Ferrimonas, for example, oxidize the same organic acids incompletely to acetate.
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In oxidizing roasting, if the temperature and gas conditions are such that the sulfide feed is completely oxidized, the process is known as "dead roasting". Sometimes, as in the case of pre-treating reverberatory or electric smelting furnace feed, the roasting process is performed with less than the required amount of oxygen to fully oxidize the feed. In this case, the process is called "partial roasting" because the sulfur is only partially removed. Finally, if the temperature and gas conditions are controlled such that the sulfides in the feed react to form metal sulfates instead of metal oxides, the process is known as "sulfation roasting".
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Animals especially but also fungi and bacteria ultimately depend upon photosynthesizing plants and phytoplankton for food and oxygen. Fire uses oxygen to oxidize compounds typically of carbon and hydrogen to water and carbon dioxide (although other elements may be involved) whether in uncontrolled conflagrations that destroy buildings and forests or the controlled fire within engines or that supply electrical energy from turbines, heat for keeping buildings warm, or the motive force that drives vehicles. Oxygen forms roughly 21% of the Earth's atmosphere; all of this oxygen is the result of photosynthesis. Pure oxygen has use in medical treatment of people who have respiratory difficulties.
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When clouds are present, the loss rate of SO2 is faster than can be explained by gas phase chemistry alone. This is due to reactions in the liquid water droplets. ;Hydrolysis Sulfur dioxide dissolves in water and then, like carbon dioxide, hydrolyses in a series of equilibrium reactions: :SO2 (g) + H2O SO2·H2O :SO2·H2O H+ \+ HSO3− :HSO3− H+ \+ SO32− ;Oxidation There are a large number of aqueous reactions that oxidize sulfur from S(IV) to S(VI), leading to the formation of sulfuric acid. The most important oxidation reactions are with ozone, hydrogen peroxide and oxygen (reactions with oxygen are catalyzed by iron and manganese in the cloud droplets).
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An inverted oxy-hydrogen blowpipe is used, with feed powder mixed with oxygen carefully fed through the blowpipe in the typical fashion, but with the addition of a third pipe to deliver oxygen—creating a tricone burner. The extra oxygen is required for successful formation of strontium titanate, which would otherwise fail to oxidize completely due to the titanium component. The ratio is ca. 1.5 volumes of hydrogen for each volume of oxygen. The highly purified feed powder is derived by first producing titanyl double oxalate salt (SrTiO(C2O4)2) by reacting strontium chloride (SrCl2) and oxalic acid ((COOH)2) with titanium tetrachloride (TiCl4).
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The thin skin and lack of coloring phenolic compounds makes Grenache a useful variety for the production of pale rosé Grenache is often used as a blending component, adding body and sweet fruitiness to a wine. The grape can be troublesome for the winemaker due to tendency to oxidize easily and lose color. To compensate for the grape's naturally low tannins and phenolic compounds, some producers will use excessively harsh pressing and hot fermentation with stems to extract the maximal amount of color and phenols from the skins. This can backfire to produce green, herbaceous flavors and coarse, astringent wine lacking the grape's characteristic vibrant fruitiness.
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In other areas, such as the dry conditions of the Columbia Valley AVA of Washington State, the grape has good resistance to drought conditions and often requires little irrigation. For the best quality, yields need to be kept in check as the vine is notably vigorous and prone to overproduction. In Chianti, most quality conscious producers limit their yields to 3 pounds (1.5 kg) of fruit per vine. Wine made from high-yielding vines tend to produce wines with light color, high acidity, and less alcohol, which are likely to oxidize ("brown") prematurely due to a lower concentration of tannins and anthocyanins (anti-oxidants).
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The environmental concerns of nitrification also contribute to interest in the use of nitrification inhibitors: the primary product, nitrate, leaches into groundwater, producing acute toxicity in multiple species of wildlife and contributing to the eutrophication of standing water. Some inhibitors of nitrification also inhibit the production of methane, a greenhouse gas. The inhibition of the nitrification process is primarily facilitated by the selection and inhibition/destruction of the bacteria that oxidize ammonia compounds. A multitude of compounds that inhibit nitrification, which can be divided into the following areas: the active site of ammonia monooxygenase (AMO), mechanistic inhibitors, and the process of N-heterocyclic compounds.
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The mechanism by which exhaust emissions are controlled depends on the method of injection and the point at which air enters the exhaust system, and has varied during the course of the development of the technology. The first systems injected air very close to the engine, either in the cylinder head's exhaust ports or in the exhaust manifold. These systems provided oxygen to oxidize (burn) unburned and partially burned fuel in the exhaust before its ejection from the tailpipe. There was significant unburned and partially burned fuel in the exhaust of 1960s and early 1970s vehicles, and so secondary air injection significantly reduced tailpipe emissions.
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The Cys215 residue is essential for the enzymatic activity of PTP1B and similar cysteine residues are required for the activity of other members of the Class I PTP family. The thiolate anion form is needed for nucleophilic activity but it is susceptible to oxidation by reactive oxygen species (ROS) in the cell which would render the enzyme non-functional. This cysteine residue has been shown to oxidize under increased cellular concentrations of hydrogen peroxide (H2O2), produced in response to EGF and insulin signaling. The thiolate is oxidized to a sulfenic acid, which is converted to a sulfenyl amide after reacting with the adjacent Ser216 residue.
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For example, lower water tables can result in lower levels of methane emission because many methanotrophic bacteria require oxic conditions to oxidize methane into carbon dioxide and water. Higher water tables, however, result in higher levels of methane emission because there is less habitable area for methanotrophic bacteria to live, and thus the methane can more easily diffuse into the atmosphere without being broken down. Often, the natural ecological progression of wetlands involves the development of one kind of wetland into one or several other kinds of wetlands. So over time, a wetland will naturally change the amount of methane emitted from its soil.
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HPPD is categorized within a class of oxygenase enzymes that usually utilize α-ketoglutarate and diatomic oxygen to oxygenate or oxidize a target molecule. However, HPPD differs from most molecules in this class due to the fact that it does not use α-ketoglutarate, and it only utilizes two substrates while adding both atoms of diatomic oxygen into the product, homogentisate. The HPPD reaction occurs through a NIH shift and involves the oxidative decarboxylation of an α-oxo acid as well as aromatic ring hydroxylation. The NIH-shift, which has been demonstrated through isotope-labeling studies, involves migration of an alkyl group to form a more stable carbocation.
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The binding of calcium ions in this way very often triggers the function or binding of Gla-protein enzymes, such as the so-called vitamin K–dependent clotting factors discussed below. Within the cell, vitamin K undergoes electron reduction to a reduced form called vitamin K hydroquinone, catalyzed by the enzyme vitamin K epoxide reductase (VKOR). Another enzyme then oxidizes vitamin K hydroquinone to allow carboxylation of Glu to Gla; this enzyme is called gamma-glutamyl carboxylase or the vitamin K–dependent carboxylase. The carboxylation reaction only proceeds if the carboxylase enzyme is able to oxidize vitamin K hydroquinone to vitamin K epoxide at the same time.
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When an engine exhaust valve is open, the pressure in the exhaust manifold is higher than atmospheric pressure. The exhaust manifold is configured in such a way that positive and negative pulses are produced during the operation of the cycle by designing it as a diffuser. The ASV has three openings: one is connected to the manifold vacuum, another is connected to the exhaust pipe and the third is open to the atmosphere. When a negative pulse is induced in the exhaust, air from the atmosphere enters the exhaust manifold through a one-way reed valve and serves to oxidize the carbon monoxide and hydrocarbons in the exhaust.
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Tin shows a chemical similarity to both of its neighbors in group 14, germanium and lead, and has two main oxidation states, +2 and the slightly more stable +4. Tin is the 49th most abundant element on Earth and has, with 10 stable isotopes, the largest number of stable isotopes in the periodic table, thanks to its magic number of protons. It has two main allotropes: at room temperature, the stable allotrope is β-tin, a silvery- white, malleable metal, but at low temperatures, it transforms into the less dense grey α-tin, which has the diamond cubic structure. Metallic tin does not easily oxidize in air.
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Tea with ingredients, China Through the centuries, a variety of techniques for processing tea, and a number of different forms of tea, were developed. During the Tang dynasty, tea was steamed, then pounded and shaped into cake form, while in the Song dynasty, loose-leaf tea was developed and became popular. During the Yuan and Ming dynasties, unoxidized tea leaves were first pan-fried, then rolled and dried, a process that stops the oxidation process that turns the leaves dark, thereby allowing tea to remain green. In the 15th century, oolong tea, in which the leaves were allowed to partially oxidize before pan-frying, was developed.
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Scheme of a proton conducting fuel cell A protonic ceramic fuel cell or PCFC is a fuel cell based around a ceramic electrolyte material that exhibits high protonic conductivity at elevated temperatures. PCFCs share the thermal and kinetic advantages of high temperature operation at 700 degrees Celsius with molten carbonate and solid oxide fuel cells, while exhibiting all of the intrinsic benefits of proton conduction in proton exchange membrane fuel cells (PEMFC) and phosphoric acid fuel cells (PAFC). The high operating temperature is necessary to achieve very high electrical conversion efficiency with hydrocarbon fuels. PCFCs can operate at high temperatures and electrochemically oxidize fossil fuels directly at the anode.
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Iron oxidation pathways in both acidophilic and circumneutral freshwater iron oxidation habitats, such as acid mine drainage or groundwater iron seeps, respectively, are better understood than marine circumneutral iron oxidation. In recent years, researchers have made progress in suggesting possibilities for how the Zetaproteobacteria oxidize iron, primarily through comparative genomics. With this technique, genomes from organisms with similar function, for example the freshwater Fe-oxidizing Betaproteobacteria and the marine Fe-oxidizing Zetaproteobacteria, are compared to find genes that may be required for this function. Identifying the iron oxidation pathway in the Zetaproteobacteria began with the publication of the first described cultured representative, M. ferrooxydans strain PV-1.
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Cells metabolize DHA and n-3 DPA by COX2 to 13-hydroxy-DHA and 13-hydroxy-DPAn-3 products and by aspirin-treated COX2 to 17-hydroxy-DHA and 17-hydroxy-DPAn-3 products and may then oxidize these products to there corresponding oxo (i.e. ketone) derivatives, 13-oxo-DHA (also termed electrophilic fatty acid oxo derivative or EFOX-D6), 13-oxo- DPAn-3 (EFOX-D5), 17-oxo-DHA (17-EFOX-D6), and 17-oxo-DPAn-3 (17-EFOX-D3). These oxo metabolites directly activate the nuclear receptor Peroxisome proliferator-activated receptor gamma and possess anti-inflammatory activity as assesses in in vitro systems.
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For example, increasing ozone concentrations to unsafe levels can increase the risk of asthma attacks. Due to the below average performance and potential health risks, Consumer Reports has advised against using ozone producing air purifiers. IQAir, the educational partner of the American Lung Association, has been a leading industry voice against ozone-producing air cleaning technology. Ozone generators used for shock treatments (unoccupied rooms) which are needed by smoke, mold, and odor remediation contractors as well as crime scene cleanup companies to oxidize and permanently remove smoke, mold, and odor damage are considered a valuable and effective tool when used correctly for commercial and industrial purposes.
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Thermal durability is particularly important for automotive SCR applications that incorporate the use of a diesel particulate filter with forced regeneration. They also have a high catalysing potential to oxidize into , which can be extremely damaging due to its acidic properties.DOE presentation Zeolite catalysts have the potential to operate at substantially higher temperature than base metal catalysts; they can withstand prolonged operation at temperatures of 900 K and transient conditions of up to 1120 K. Zeolites also have a lower potential for potentially damaging oxidation. Iron- and copper-exchanged zeolite urea SCRs have been developed with approximately equal performance to that of vanadium- urea SCRs if the fraction of the is 20% to 50% of the total .
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When an inductive circuit is opened, the current through the inductance collapses quickly, creating a large voltage across the open circuit of the switch or relay. If the inductance is large enough, the energy may generate a spark, causing the contact points to oxidize, deteriorate, or sometimes weld together, or destroying a solid-state switch. A snubber capacitor across the newly opened circuit creates a path for this impulse to bypass the contact points, thereby preserving their life; these were commonly found in contact breaker ignition systems, for instance. Similarly, in smaller scale circuits, the spark may not be enough to damage the switch but may still radiate undesirable radio frequency interference (RFI), which a filter capacitor absorbs.
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AMD is formed by weathering that oxidizes sulfur minerals to sulfate and acid, and this process is exacerbated by microbes that oxidize reduced minerals. The production of acid, including sulfuric acid, causes metals to leach from waste rock into water and has contaminated nearby Joe Creek with cadmium, copper, lead, arsenic and zinc at levels that are toxic to aquatic life. Joe Creek is unable to contain any self-sustaining populations of fish due to the mining waste. The waste at Blue Ledge is particularly hazardous because it is mainly composed of small particles, which have greatly increased surface area when compared to large rocks, and therefore a high rate of metal leaching.
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Red phosphorus, used as a charring-promoter flame retardant, facilitates silver migration when present in packaging. It is normally coated with aluminium hydroxide; if the coating is incomplete, the phosphorus particles oxidize to the highly hygroscopic phosphorus pentoxide, which reacts with moisture to phosphoric acid. This is a corrosive electrolyte that in the presence of electric fields facilitates dissolution and migration of silver, short-circuiting adjacent packaging pins, lead frame leads, tie bars, chip mount structures, and chip pads. The silver bridge may be interrupted by thermal expansion of the package; thus, disappearance of the shorting when the chip is heated and its reappearance after cooling is an indication of this problem.
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Unlike gasoline and liquefied petroleum gas engines, diesel engines do not use high-voltage spark ignition (spark plugs). An engine running on diesel compresses the air inside the cylinder to high pressures and temperatures (compression ratios from 14:1 to 18:1 are common in current diesel engines); the engine generally injects the diesel fuel directly into the cylinder, starting a few degrees before top dead center (TDC) and continuing during the combustion event. The high temperatures inside the cylinder cause the diesel fuel to react with the oxygen in the mix (burn or oxidize), heating and expanding the burning mixture to convert the thermal/pressure difference into mechanical work, i.e., to move the piston.
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Nickel Rim mine in Sudbury, Ontario From 1953 to 1958 Nickel Rim mines operating around Sudbury, Ontario deposited their mine tailings in an impoundment near the mine. The water in the impoundment was later tested and found to have low pH and high concentrations of iron, sulphur and dissolved metals such as aluminum and nickel. This is due to the oxidation of the tailings (usually sulfide minerals like pyrrhotite). The limited oxygen diffusing into the layers causes the tailings oxidize for a longer period of time, for this reason the water at the impoundment is going to discharge water with high concentrations of iron and sulphate for at least the next 50 years.
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Fat over lean refers to the principle in oil painting of applying paint with a higher oil to pigment ratio ('fat') over paint with a lower oil to pigment ratio ('lean') to ensure a stable paint film, since it is believed that the paint with the higher oil content remains more flexible. Oil paint dries at different rates due to the differing drying properties of the constituent pigment. However, everything else being equal, the higher the oil to pigment ratio, the longer the oil binder will take to oxidize, and the more flexible the paint film will be. Conversely, the lower the oil content, the faster the paint dries, and the more brittle it will be.
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A 2007 study examined HIIT's physiological effects on fat oxidation in moderately active women. The participants in the study performed HIIT (defined as ten sets of 4-minute cycling bursts at an intensity of 90% VO2max separated by 2 minutes of rest) every other day over a 2-week period. The study found that seven sessions of HIIT over a 2-week period improved whole body fat oxidation and the capacity for skeletal muscle to oxidize fat in moderately active women. A 2010 systematic review of HIIT summarized the results of HIIT on fat loss and stated that HIIT can result in modest reductions of subcutaneous fat in young and healthy individuals, but greater reductions for overweight individuals.
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Anaerobic denitrification coupled to methane oxidation was first observed in 2008, with the isolation of a methane- oxidizing bacterial strain found to oxidize methane independently. This process uses the excess electrons from methane oxidation to reduce nitrates, effectively removing both fixed nitrogen and methane from aquatic systems in habitats ranging from sediment to peat bogs to stratified water columns. The process of anaerobic denitrification may contribute significantly to the global methane and nitrogen cycles, especially in light of the recent influx of both due to anthropogenic changes. The extent to which anthropogenic methane affects the atmosphere is known to be a significant driver of climate change, and considering it is multiple times more potent than carbon dioxide.
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In studying the hypothetical reaction mechanism for eflornithine, information collected from radioactive peptide and eflornithine mapping, high pressure liquid chromatography, and gas phase peptide sequencing suggested that Lys-69 and Cys-360 are covalently bound to eflornithine in T. brucei ODC's active site. Utilizing fast-atom bombardment mass spectrometry (FAB-MS), the structural conformation of eflornithine following its interaction with ODC was determined to be (S)-((2-(1-pyrroline-methyl) cysteine, a cyclic imine adduct. Presence of this particular product was supported by the possibility to further reduce the end product to (S)-((2-pyrrole) methyl) cysteine in the presence of NaBH4 and oxidize the end product to (S)-((2-pyrrolidine) methyl) cysteine (Figure 2).
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Biogenic Mn oxides (BMOs) are naturally occurring Mn oxides that have the ability to oxidize various redox-sensitive elements. A. strictum is a Mn(II)-oxidizing fungus that forms BMOs through the action of Mn(II) oxidase. In the presence of BMOs in buffer solutions with no additional nutrients, A. strictum is capable of sequestering high Mn(II) concentrations for at least 8 days, in which the amount of dissolved Mn(II) decreases rapidly in several hours and is converted to oxidized Mn(II). Deaeration of the buffer solution with N2 gas purging suppressed Mn(II) conversion, but this suppression is easily rescued by aeration, implying that dissolved oxygen is required for the Mn(II) sequestration and oxidation process.
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The halides, and the oxides and their derivatives are illustrative examples. The +5 state is less stable than the +3, but relatively easier to attain than with arsenic. This is explained by the poor shielding afforded the arsenic nucleus by its 3d10 electrons. In comparison, the tendency of antimony (being a heavier atom) to oxidize more easily partially offsets the effect of its 4d10 shell.Greenwood & Earnshaw 2002, p. 553; Massey 2000, p. 269 Tripositive antimony is amphoteric; pentapositive antimony is (predominately) acidic.King 1994, p.171 Consistent with an increase in metallic character down group 15, antimony forms salts or salt-like compounds including a nitrate Sb(NO3)3, phosphate SbPO4, sulfate Sb2(SO4)3 and perchlorate Sb(ClO4)3.
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Many scientists believe that the data were due to inorganic chemical reactions of the soil; however, this view may be changing due to a variety of discoveries and studies since Viking, including, the discovery of near-surface ice near the Viking landing zone, the possibility of perchlorate destruction of organic matter, and the reanalysis of GCMS data by scientists in 2018. Some scientists still believe the results were due to living reactions. The formal declaration at the time of the mission was that the discovery of organic chemicals was inconclusive. Mars has almost no ozone layer, unlike the Earth, so UV light sterilizes the surface and produces highly reactive chemicals such as peroxides that would oxidize any organic chemicals.
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Some supergene sulfide deposits can be leached using a bacterial oxidation heap leach process to oxidize the sulfides to sulfuric acid, which also allows for simultaneous leaching with sulfuric acid to produce a copper sulfate solution. As with oxide ores, solvent extraction and electrowinning technologies are used to recover the copper from the pregnant leach solution. Supergene sulfide ores rich in native copper minerals are refractory to treatment with sulfuric acid leaching on all practicable time scales, and the dense metal particles do not react with froth flotation media. Typically, if native copper is a minor part of a supergene profile it will not be recovered and will report to the tailings.
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The wiring inside every single Totem speaker is unique and requires us to use roughly 40 different types. Each and every wire, inside each and every Totem network, feeding each and every Totem driver, has been painstakingly selected by Vince. While they are all different, all are 99.999% oxygen free silver plated copper and Teflon coated so they will never oxidize and keep the electron flow the same over the long life of the speaker. These ultra-high grade wires have also been chosen because the copper has been stretched slowly, allowing the molecular crystals to align themselves in a very cohesive fashion once the speaker has had a proper break in time.
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A planar zirconia sensor (schematic picture) The zirconium dioxide, or zirconia, lambda sensor is based on a solid-state electrochemical fuel cell called the Nernst cell. Its two electrodes provide an output voltage corresponding to the quantity of oxygen in the exhaust relative to that in the atmosphere. An output voltage of 0.2 V (200 mV) DC represents a "lean mixture" of fuel and oxygen, where the amount of oxygen entering the cylinder is sufficient to fully oxidize the carbon monoxide (CO), produced in burning the air and fuel, into carbon dioxide (CO2). An output voltage of 0.8 V (800 mV) DC represents a "rich mixture", which is high in unburned fuel and low in remaining oxygen.
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One style of Maury known as rancio is produced when the wine is racked into clear glass demi-johns or bonbonne and left out in the summer sun to oxidize and age. This causes many of the colour compounds and tannins in the wines to fall out, leaving a thick, dark coloured deposit in the bonbonne. This deposit is allowed to stay in the bonbonne to influence the colour and flavour of resulting vintages of wine that are aged in the container. Once the wine has finished aging for the summer it is usually blended with wine that has spent time aging in large foudres oak cask or sold separately as Maury Rancio.
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Since the iodide ion is a mild reducing agent, is easily oxidised to by powerful oxidising agents such as chlorine: : This reaction is employed in the isolation of iodine from natural sources. Air will oxidize iodide, as evidenced by the observation of a purple extract when aged samples of KI are rinsed with dichloromethane. As formed under acidic conditions, hydriodic acid (HI) is a stronger reducing agent.N. N. Greenwood, A. Earnshaw, Chemistry of the Elements, Pergamon Press, Oxford, UK, 1984Handbook of Chemistry and Physics, 71st edition, CRC Press, Ann Arbor, Michigan, 1990The Merck Index, 7th edition, Merck & Co., Rahway, New Jersey, 1960 Like other iodide salts, forms when combined with elemental iodine.
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Atmospheric N inputs mainly include oxides of N (NOx), ammonia (NH3), and nitrous oxide (N2O) from aquatic and terrestrial ecosystems, and NOx from fossil fuel and biomass combustion. In agroecosystems, fertilizer application has increased microbial nitrification (aerobic process in which microorganisms oxidize ammonium [NH4+] to nitrate [NO3−]) and denitrification (anaerobic process in which microorganisms reduce NO3− to atmospheric nitrogen gas [N2]). Both processes naturally leak nitric oxide (NO) and nitrous oxide (N2O) to the atmosphere. Of particular concern is N2O, which has an average atmospheric lifetime of 114–120 years,John T. Houghton, Y. Ding, D. J. Griggs, M. Noguer, P. J. van der Linden, X. Dai, K. Maskell, and C. A. Johnson. 2001.
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This system of enzymes acts in three stages to firstly oxidize the xenobiotic (phase I) and then conjugate water-soluble groups onto the molecule (phase II). The modified water-soluble xenobiotic can then be pumped out of cells and in multicellular organisms may be further metabolized before being excreted (phase III). In ecology, these reactions are particularly important in microbial biodegradation of pollutants and the bioremediation of contaminated land and oil spills. Many of these microbial reactions are shared with multicellular organisms, but due to the incredible diversity of types of microbes these organisms are able to deal with a far wider range of xenobiotics than multicellular organisms, and can degrade even persistent organic pollutants such as organochloride compounds.
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Hovering male rufous hummingbird Digital imaging velocimetry was used to capture rufous hummingbird wing movements on film, enabling determination that the bird supports its body weight during hovering primarily by wing downstrokes (75% of lift) rather than by upstrokes (25% of lift). When hovering during fasting, rufous hummingbirds oxidize fatty acids to support metabolism and food energy requirements, but can rapidly switch to carbohydrate metabolism (within 40 minutes) after feeding on flower nectar. Rocky Mountain Beeplant in Wyoming, USA Both male and female S. rufus are territorial; however, they defend different types of territories. The more aggressive males fight to defend areas with dense flowers, pushing females into areas with more sparsely populated flowers.
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Haematoxylin stain formulations can be broadly classified based on how the haematoxylin is oxidized (or ripened) and by choice of the mordant used. Haematoxylin stain formulations may either be natural oxidized by exposure to air and sunlight, or more commonly, especially in commercially prepared solutions, chemically oxidized using sodium iodate. Commonly only enough oxidizer is added to convert one half of the haematoxylin to haematein, allowing the remainder to naturally oxidize during use, this extends the staining solution's useful life as more haematein is produced, while some haematein is further oxidized to oxyhaematein. Of the metallic salts used as mordants, aluminium is the most common, other mordants include salts of iron, tungsten, molybdenum and lead.
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Methanohalophilus mahii has a unique suppressor tRNA with a modified pyrrolysine, an amino acid that is most commonly found in prokaryotes, that can recognize and bind to the amber STOP codon (UAG) which is also coded for by the genes used for methylamine methyltransferases. This species was also the first member to have its genome completely sequenced in the genus Methanohalophilus[1], which comprises mildly halophilic, methylotrophic methanogens. These archaea in general are known to greatly contribute to the carbon mineralization process in marine ecosystems. Specifically, the oxidative methylotrophic pathway Methanohalophilus mahii utilizes allows the species to oxidize methane to carbon dioxide, which, in turn, is used by other plants and organisms.
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Free radical reactions catalyzed by ultraviolet light from the sun oxidize unburned hydrocarbons to aldehydes, ketones, and dicarbonyl compounds, whose secondary reactions create peroxyacyl radicals, which combine with nitrogen dioxide to form peroxyacyl nitrates. The most common peroxyacyl radical is peroxyacetyl, which can be formed from the free radical oxidation of acetaldehyde, various ketones, or the photolysis of dicarbonyl compounds such as methylglyoxal or diacetyl. Since they dissociate quite slowly in the atmosphere into radicals and NO2, PANs are able to transport these unstable compounds far away from the urban and industrial origin. This is important for tropospheric ozone production as PANs transport NOx to regions where it can more efficiently produce ozone.
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Sodium borohydride could potentially be used in more conventional hydrogen fuel cell systems as a means of storing hydrogen. The hydrogen can be regenerated for a fuel cell by catalytic decomposition of the borohydride: :NaBH4 \+ 2H2O → NaBO2 \+ 4H2 Direct borohydride fuel cells decompose and oxidize the borohydride directly, side-stepping hydrogen production and even producing slightly higher energy yields:Ma, Choudhury, Sahai - A comprehensive review of direct borohydride fuel cells :Cathode: 2O2 \+ 4H2O + 8e− → 8OH− (E0 = +0.4V) :Anode: NaBH4 \+ 8OH− → NaBO2 \+ 6H2O + 8e− (E0 = -1.24 V) ::Total E0 = +1.64V The simplified reaction is: :NaBH4 \+ 2O2 → NaBO2 \+ 2H2O + Electricity The working temperature of a direct sodium borohydride fuel cell is 70 °C (158 °F).
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The main advantage to resistive heating is the precise measurement of temperature with thermocouples, but the temperature range is limited by the properties of the diamond which will oxidize in air at 700 °C The use of an inert atmosphere can extend this range above 1000 °C. With laser heating the sample can reach temperature above 5000 °C, but the minimum temperature that can be measured when using a laser-heating system is ~1200 °C and the measurement is much less precise. Advances in resistive heating are closing the gap between the two techniques so that systems can be studied from room temperature to beyond 5700 °C with the combination of the two.
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Glyoxalase I was originally believed to operate by the transfer of a hydride, which is a proton surrounded by two electrons (H-). In this, it was thought to resemble the classic Cannizzaro reaction mechanism, in which the attack of a hydroxylate on an aldehyde renders it into a tetravalent alcohol anion; this anion donates its hydrogens to a second aldehyde, forming a carboxylic acid and an alcohol. (In effect, two identical aldehydes reduce and oxidize each other, leaving the net oxidation state the same.) In glyoxalase I, such a hydride-transfer mechanism would work as follows. The attack of the glutathione would leave a charged O- and the aldehyde hydrogen bound to C1.
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Periodic acid Periodic acid–Schiff (PAS) is a staining method used to detect polysaccharides such as glycogen, and mucosubstances such as glycoproteins, glycolipids and mucins in tissues. The reaction of periodic acid oxidizes the vicinal diols in these sugars, usually breaking up the bond between two adjacent carbons not involved in the glycosidic linkage or ring closure in the ring of the monosaccharide units that are parts of the long polysaccharides, and creating a pair of aldehydes at the two free tips of each broken monosaccharide ring. The oxidation condition has to be sufficiently regulated so as to not oxidize the aldehydes further. These aldehydes then react with the Schiff reagent to give a purple-magenta color.
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Apart from the structural damage of membrane, metal ions also contribute to the generation of reactive oxygen species (ROS) inside the cell. ROS would oxidize glutathione, which is vital compound in bacteria carry out antioxidant defense system to combat against ROS. Consequently, the cell would be destructed due to the reduction of intracellular ATP level, cellular enzyme denaturation, interruption of protein synthesis and DNA damage contributed by the oxidative stress or direct interaction with the metal ion. Since the interaction of metal ion with some atoms, such as nitrogen, oxygen and sulphur, which are abundant in most cellular biomolecules, is very strong and non-specific, therefore, metal ion could possess a broad spectrum of antimicrobial property.
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An important part of the operation is electrolyte gel which is applied between the electrode and tissues. The gel contains free chloride ions such that the charge can be carried through the electrolyte, therefore the electrolyte can be considered as conductive for ion current as the human tissues. When the ion current exists, the silver atoms in the electrode oxidize and discharge cations to the electrolyte and the electrons carry charge through the lead wire. At the same time, the chloride ions which are anions in the electrolyte travel toward the electrode and they are reduced as they bond with silver of the electrode resulting in silver chloride and free electrons to deliver to the lead wire.
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Commercial vacuum tubes are evacuated at manufacture to about .C. Robert Meissner (ed.), Vacuum Technology Transactions: Proceedings of the Sixth National Symposium, Elsevier, 2016, page 96 To prevent gases from compromising the tube's vacuum, modern tubes are constructed with "getters", which are usually small, circular troughs filled with metals that oxidize quickly, barium being the most common. While the tube envelope is being evacuated, the internal parts except the getter are heated by RF induction heating to evolve any remaining gas from the metal parts. The tube is then sealed and the getter is heated to a high temperature, again by radio frequency induction heating, which causes the getter material to vaporize and react with any residual gas.
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Many soil bacteria possess the enzyme urease, which catalyzes conversion of urea to ammonia (NH3) or ammonium ion (NH4+) and bicarbonate ion (HCO3−). Thus urea fertilizers rapidly transform to the ammonium form in soils. Among the soil bacteria known to carry urease, some ammonia-oxidizing bacteria (AOB), such as species of Nitrosomonas, can also assimilate the carbon dioxide the reaction releases to make biomass via the Calvin cycle, and harvest energy by oxidizing ammonia (the other product of urease) to nitrite, a process termed nitrification. Nitrite-oxidizing bacteria, especially Nitrobacter, oxidize nitrite to nitrate, which is extremely mobile in soils because of its negative charge and is a major cause of water pollution from agriculture.
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Although nanosized anatase TiO2 does not absorb visible light, it does strongly absorb ultraviolet (UV) radiation (hv), leading to the formation of hydroxyl radicals. This occurs when photo-induced valence bond holes (h+vb) are trapped at the surface of TiO2 leading to the formation of trapped holes (h+tr) that cannot oxidize water. :TiO2 \+ hv → e− \+ h+vb :h+vb → h+tr :O2 \+ e− → O2•− :O2•− \+ O2•−\+ 2 → H2O2 \+ O2 :O2•− \+ h+vb → O2 :O2•− \+ h+tr → O2 : + h+vb → HO• :e− \+ h+tr → recombination :Note: Wavelength (λ)= 387 nm This reaction has been found to mineralize and decompose undesirable compounds in the environment, specifically the air and in wastewater.Synthetic single crystals of TiO2, ca.
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MtDNA, in contrast to nuclear DNA, is characterized by elevated basal levels of 8-OHdG, a marker of oxidative damage. The high content of oxidative damage in mtDNA is attributed to the close proximity of mtDNA to ROS and relatively inefficient DNA repair mechanisms that can lead to the accumulation of DNA lesions. They have shown that oxidative burst during NETosis can oxidize mtDNA and the released oxidized mtDNA by itself, or in complex with TFAM, can generate prominent induction of type I IFNs. Oxidized mtDNA generated during programmed cell death is not limited to activate TLR9, but was shown to also engage the NRLP3 inflammasome, leading to the production of pro-inflammatory cytokines, IL-1β, and IL-18.
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Heavy-duty snubber capacitor with screw terminals When an inductive circuit is opened, the current through the inductance collapses quickly, creating a large voltage across the open circuit of the switch or relay. If the inductance is large enough, the energy will generate an electric spark, causing the contact points to oxidize, deteriorate, or sometimes weld together, or destroying a solid- state switch. A snubber capacitor across the newly opened circuit creates a path for this impulse to bypass the contact points, thereby preserving their life; these were commonly found in contact breaker ignition systems, for instance. Similarly, in smaller scale circuits, the spark may not be enough to damage the switch but will still radiate undesirable radio frequency interference (RFI), which a filter capacitor absorbs.
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Pyruvate dehydrogenase complex reaction Pyruvate decarboxylation or pyruvate oxidation, also known as the link reaction, is the conversion of pyruvate into acetyl-CoA by the enzyme complex pyruvate dehydrogenase complex. The reaction may be simplified as: 1 Pyruvate + 1 NAD+ \+ CoA → 1 Acetyl-CoA + NADH + CO2 \+ H+ Pyruvate oxidation is the step that connects glycolysis and the Krebs cycle. In glycolysis, a single glucose molecule (6 carbons) is split into 2 pyruvates (3 carbons each), hence link reaction occurs twice for each glucose molecule to produce a total of 2 acetyl-CoA molecules, which can then enter the Krebs cycle. Energy-generating ions and molecules such as amino acids and carbohydrates enter the Krebs cycle as acetyl coenzyme A and oxidize in the cycle.
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Nitrogen oxides are released during manufacturing of nitrogen fertilizers. Though nitrous oxide is emitted during its application, it is then reacted in atmosphere to form nitrogen oxides. This third source is attributed to the reaction of atmospheric nitrogen, N2, with radicals such as C, CH, and CH2 fragments derived from fuel, rather than thermal or fuel processes. Occurring in the earliest stage of combustion, this results in the formation of fixed species of nitrogen such as NH (nitrogen monohydride), NCN (diradical cyanonitrene), HCN (hydrogen cyanide), •H2CN (dihydrogen cyanide) and •CN (cyano radical) which can oxidize to NO. In fuels that contain nitrogen, the incidence of prompt is comparatively small and it is generally only of interest for the most exacting emission targets.
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A stainless steel cell, full of plastic caps of different dimension, slowly rotates (1–3 rpm) partially submerged inside a tank, where there are wastewaters to be purified. Plastic caps spontaneously form a bacterial film that progressively presents, at first, heterotrophic bacteria development which are able to nourish of organic carbon pollutants; then the decrease of COD and BOD concentration and then the development of autotrophic bacteria. They belong to the nitrosomonas and nitrobacter category and they are able to oxidize ammonium, transforming it into nitrites and nitrates. The cell containing the carriers (caps) can be flooded as needed; in this way the depuration process control is obtained and it can be oriented both to the carbon removal both to the wastewaters denitrification.
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In contrast to the contractile apparatus, studies on various rodent skeletal muscle metabolic enzymes have revealed a variety of responses with no clear-cut adaptive changes in oxidative enzyme expression. These observations are consistent with the results of studies focusing on mitochondrial function after 9 days of spaceflight in which no reduction in the capacity of skeletal muscle mitochondria to metabolize pyruvate (a carbohydrate derivative) was observed. These analyses were carried out under state 3 metabolic conditions, that is, non-limiting amounts of substrate and cofactors to simulate an energy turnover demand similar to that of high-intensity exercise. However, when a fatty acid substrate was tested, a reduction in the capacity of different muscle types to oxidize the long-chain fatty acid, palmitate, was observed.
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Thorium dioxide (thoria) can be used in nuclear reactors as ceramic fuel pellets, typically contained in nuclear fuel rods clad with zirconium alloys. Thorium is not fissile (but is "fertile", breeding fissile uranium-233 under neutron bombardment); hence, it must be used as a nuclear reactor fuel in conjunction with fissile isotopes of either uranium or plutonium. This can be achieved by blending thorium with uranium or plutonium, or using it in its pure form in conjunction with separate fuel rods containing uranium or plutonium. Thorium dioxide offers advantages over conventional uranium dioxide fuel pellets, because of its higher thermal conductivity (lower operating temperature), considerably higher melting point, and chemical stability (does not oxidize in the presence of water/oxygen, unlike uranium dioxide).
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Many thiolate complexes are prepared by redox reactions. Organic disulfides oxidize low valence metals, as illustrated by the oxidation of titanocene dicarbonyl: :(C5H5)2Ti(CO)2 \+ (C6H5S)2 → (C5H5)2Ti(SC6H5)2 \+ 2 CO Some metal centers are oxidized by thiols, the coproduct being hydrogen gas: :Fe3(CO)12 \+ 2 C2H5SH → Fe2(SC2H5)2(CO)6 \+ Fe(CO)5 \+ CO + H2 These reactions probably proceed via oxidative addition of the thiol. Thiols and especially thiolate salts are reducing agents. Consequently, they induce redox reactions with certain transition metals. This phenomenon is illustrated by the synthesis of cuprous thiolates from cupric precursors: :4 HSC6H5 \+ 2 CuO → 2 Cu(SC6H5) + (C6H5S)2 \+ 2 H2O Thiolate clusters of the type [Fe4S4(SR)4]2− occur in iron–sulfur proteins.
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DAO acts in the brain to oxidize specific D-amino acids using the FAD region (flavin adenine dinucleotide region) and is commonly thought to be produced in the hindbrain, although there is new evidence of DAO expression in the forebrain as well. The DAO present in the forebrain seems to be inactive, however, causing speculation on the topic of DAO function in the forebrain as opposed to the hindbrain where the function is more well-known. The consensus is that DAO is produced and is active in glial cells, most specifically in cerebellar type-1 and type-2 astrocytes, and the D-serine amino acid that is produced by DAO in these cells has been shown to increase synaptic NMDA receptor activity.
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This photoredox transformation was shown to be mechanistically distinct from another organocatalytic radical process termed singly-occupied molecular orbital (SOMO) catalysis. SOMO catalysis employs superstoichiometric ceric ammonium nitrate (CAN) to oxidize the catalytically-generated enamine to the corresponding radical cation, which can then add to a suitable coupling partner such as allyl silane. This type of mechanism is excluded for the photocatalytic alkylation reaction because whereas enamine radical cation was observed to cyclize onto pendant olefins and open cyclopropane radical clocks in SOMO catalysis, these structures were unreactive in the photoredox reaction. Diagram of Enantioselective Alkylation of Aldehydes via the synergistic combination of organo- and photoredox catalysis This transformation include alkylations with other classes of activated alkyl halides of synthetic interest.
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Because the ratio of hydrogen to oxygen atoms in all carbohydrates is always the same as that in water—that is, 2 to 1—all of the oxygen consumed by the cells is used to oxidize the carbon in the carbohydrate molecule to form carbon dioxide. Consequently, during the complete oxidation of a glucose molecule, six molecules of carbon dioxide and six molecules of water are produced and six molecules of oxygen are consumed. The overall equation for this reaction is: :C6H12O6 \+ 6 O2 → 6 CO2 \+ 6 H2O (30-32 ATP molecules produced depending on type of mitochondrial shuttle, 5-5.33 ATP molecules per molecule of oxygen) Because the gas exchange in this reaction is equal, the respiratory quotient (R.Q.) for carbohydrate is unity or 1.0: :R.
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Under Argentine wine laws, if a grape name appears on the wine label, 100% of the wine must be composed that grape variety. The backbone of the early Argentine wine industry was the high yielding, pink skin grapes Cereza, Criolla Chica and Criolla Grande which still account for nearly 30% of all vines planted in Argentina today. Very vigorous vines, these varieties are able to produce many clusters weighing as much as 9 pounds (4 kg) and tend to produce pink or deeply colored white wines that oxidize easily and often have noticeable sweetness. These varieties are often used today for bulk jug wine sold in 1 liter cardboard cartons or as grape concentrate which is exported worldwide with Japan being a considerably large market.
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In engineering, sulfate-reducing microorganisms can create problems when metal structures are exposed to sulfate-containing water: Interaction of water and metal creates a layer of molecular hydrogen on the metal surface; sulfate- reducing microorganisms then oxidize the hydrogen while creating hydrogen sulfide, which contributes to corrosion. Hydrogen sulfide from sulfate- reducing microorganisms also plays a role in the biogenic sulfide corrosion of concrete. It also occurs in sour crude oil. Some sulfate-reducing microorganisms play a role in the anaerobic oxidation of methane: :CH4 \+ SO42− -> HCO3− \+ HS− \+ H2O An important fraction of the methane formed by methanogens below the seabed is oxidized by sulfate-reducing microorganisms in the transition zone separating the methanogenesis from the sulfate reduction activity in the sediments.
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Contamination of maize by A. candidus has been shown to increase fat acidity content from the breakdown maize oil, leading to discoloration of the germ and loss of viability, A. candidus can oxidize tryptamine to traptophol, and use glucose and other sugars in the substrate and converts it into D-mannitol. A. candidus may sometimes cause self-heating which increases the temperature of the contaminated crop, in order to increase its competitiveness with other fungi living in the organism or environment at low relative humidity. There have been cases reported where contamination by A. candidus resulted in an increase in surrounding temperature by 20-26 °C. A. candidus has also been reported to use and degrade straw lignin, arabinoxylan, and cellulose.
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This shift precipitated a drop in iron prices since the process no longer required charcoal, the production of which was labor-intensive. This was a practice that was later adopted in the US as well. Although steel is an alloy of iron and a small amount of carbon, historically steel and iron-making were intended for different products given the high costs of steel over wrought iron. The main difficulty with making steel is that its higher melting point than pig or cast iron was not easily achievable in large-scale production until methods that introduced air or oxygen to oxidize the carbon in the molten pig iron were developed, allowing the direct conversion of molten pig iron to molten steel.
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This process can continue well beyond the immediately exposed metal surface, potentially reacting with a large part of the bulk aluminium before it finally ends. The net result is similar to the mercury electrodes often used in electrochemistry, except instead of providing electrons from an electrical supply they are provided by the aluminium which becomes oxidized in the process. The reaction that occurs at the surface of the amalgam may actually be a hydrogenation rather than a reduction. The presence of water in the solution is reportedly necessary; the electron rich amalgam will oxidize aluminium and reduce H+ from water, creating aluminium hydroxide (Al(OH)3) and hydrogen gas (H2). The electrons from the aluminium reduce mercuric Hg2+ ion to metallic mercury.
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A cracked coconut and a bottle of coconut oil Coconut oil, or copra oil, is an edible oil extracted from the kernel or meat of mature coconuts harvested from the coconut palm (Cocos nucifera). It has various applications. Because of its high saturated fat content, it is slow to oxidize and, thus, resistant to rancidification, lasting up to six months at 24 °C (75 °F) without spoiling. Due to its high levels of saturated fat, the World Health Organization, the United States Department of Health and Human Services, United States Food and Drug Administration, American Heart Association, American Dietetic Association, British National Health Service, British Nutrition Foundation, and Dietitians of Canada advise that coconut oil consumption should be limited or avoided.
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European tastes also started to change as the emergence of the more accessible port wine hit the British wine market - being particularly encouraged by the favorable Methuen Treaty. This left many Sherry merchants with excess stock that could do little more than sit and age in oak barrels. Unlike during the boom market when Sherry makers were selling their stocks as fast as they could produce it, these aging stocks began to slightly oxidize and develop more concentrated and nutty flavors.H. Johnson Vintage: The Story of Wine pg 318-325, Simon & Schuster 1989 As a few orders of Sherry would trickle in, the Sherry merchants would bottle a small quantity and then top up the rest of the barrel with wine from some of their newer inventory.
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Manzanilla The taste of most of the wine world was still geared towards sweet and strong wines, and the Portuguese were seeing great success in adding brandy to make their port wines stronger. The Jerezanos began to experiment with adding brandy to Sherry and discovered that the increased alcohol content also had the effect of killing off the flor, which then made the wine oxidize more and develop into another style of wine. The merchants began to call this wine oloroso meaning "pungent". The Sherry makers in Sanlúcar were a little more restrained in the use of their brandy, finding that the unique aspect of flor took on new distinction amid the salty sea breezes that cooled most of the area's bodegas.
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In enzymology, a cyanocobalamin reductase (cyanide-eliminating) () is an enzyme that catalyzes the chemical reaction :cob(I)alamin + cyanide + NADP+ \rightleftharpoons cyanocob(III)alamin + NADPH + H+ The 3 substrates of this enzyme are cob(I)alamin, cyanide, and NADP+, whereas its 3 products are cyanocob(III)alamin, NADPH, and H+. This enzyme belongs to the family of oxidoreductases, specifically those that oxidize metal ions and use NAD+ or NADP+ as an electron acceptor (for that oxidization reaction). The systematic name of this enzyme class is cob(I)alamin, cyanide:NADP+ oxidoreductase. Other names in common use include cyanocobalamin reductase, cyanocobalamin reductase (NADPH, cyanide-eliminating), cyanocobalamin reductase (NADPH, CN- eliminating), and NADPH:cyanocob(III)alamin oxidoreductase (cyanide- eliminating). This enzyme participates in porphyrin and chlorophyll metabolism.
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Iodometry in its many variations is extremely useful in volumetric analysis. Examples include the determination of copper(II), chlorate, Hydrogen peroxide, and dissolved oxygen: :2 Cu2+ \+ 4 I− → 2 CuI + I2 : 6 H+ \+ ClO3− \+ 6 I− → 3 I2 \+ Cl− \+ 3 H2O : 2 H+ \+ H2O2 \+ 2 I− → I2 \+ 2 H2O : 2 H2O + 4 Mn(OH)2 \+ O2 → 4 Mn(OH)3 : 2 Mn3+ \+ 2 I− → I2 \+ 2 Mn2+ Available chlorine refers to chlorine liberated by the action of dilute acids on hypochlorite. Iodometry is commonly employed to determine the active amount of hypochlorite in bleach responsible for the bleaching action. In this method, excess but known amount of iodide is added to known volume of sample, in which only the active (electrophilic) can oxidize iodide to iodine.
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The different milling techniques produce visibly different results, but can be made to produce nutritionally and functionally equivalent output. Stone-ground flour is, however, preferred by many bakers and natural food advocates because of its texture, nutty flavour, and the belief that it is nutritionally superior and has a better baking quality than steel-roller-milled flour. It is claimed that, as the stones grind relatively slowly, the wheat germ is not exposed to the sort of excessive temperatures that could cause the fat from the germ portion to oxidize and become rancid, which would destroy some of the vitamin content. Stone-milled flour has been found to be relatively high in thiamin, compared to roller-milled flour, especially when milled from hard wheat.
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Sludge from a pond; the black color is due to metal sulfides Hydrogen sulfide is a central participant in the sulfur cycle, the biogeochemical cycle of sulfur on Earth. In the absence of oxygen, sulfur-reducing and sulfate-reducing bacteria derive energy from oxidizing hydrogen or organic molecules by reducing elemental sulfur or sulfate to hydrogen sulfide. Other bacteria liberate hydrogen sulfide from sulfur- containing amino acids; this gives rise to the odor of rotten eggs and contributes to the odor of flatulence. As organic matter decays under low- oxygen (or hypoxic) conditions (such as in swamps, eutrophic lakes or dead zones of oceans), sulfate-reducing bacteria will use the sulfates present in the water to oxidize the organic matter, producing hydrogen sulfide as waste.
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TiN has a Vickers hardness of 1800–2100, a modulus of elasticity of 251 GPa, a thermal expansion coefficient of 9.35 K−1, and a superconducting transition temperature of 5.6 K. TiN will oxidize at 800 °C in a normal atmosphere. It is chemically stable at 20 °C, according to laboratory tests, but can be slowly attacked by concentrated acid solutions with rising temperatures. Depending on the substrate material and surface finish, TiN will have a coefficient of friction ranging from 0.4 to 0.9 against another TiN surface (non-lubricated). The typical TiN formation has a crystal structure of NaCl-type with a roughly 1:1 stoichiometry; TiNx compounds with x ranging from 0.6 to 1.2 are, however, thermodynamically stable.
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An alternative protocol uses a solution of iodate ion (for instance potassium iodate) to which an acidified solution (again with sulfuric acid) of sodium bisulfite is added. In this protocol, iodide ion is generated by the following slow reaction between the iodate and bisulfite: :IO3− \+ 3 HSO3− → I− \+ 3 HSO4− This first step is the rate determining step. Next, the iodate in excess will oxidize the iodide generated above to form iodine: :IO3− \+ 5 I− \+ 6 H+ → 3 I2 \+ 3 H2O However, the iodine is reduced immediately back to iodide by the bisulfite: :I2 \+ HSO3− \+ H2O → 2 I− \+ HSO4− \+ 2 H+ When the bisulfite is fully consumed, the iodine will survive (i.e., no reduction by the bisulfite) to form the dark blue complex with starch.
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This stratification is maintained by a strong pycnocline which restricts ventilation of deep waters and results in an intermediate layer called the chemocline, a sharp boundary separating oxic surface waters from anoxic bottom waters usually between 50m and 100m depth, with interannual variation attributed to large scale changes in temperature. Well-mixed, oxic conditions exist above the chemocline and sulfidic conditions are dominant below. Surface oxygen and deep water sulfide do not overlap via vertical mixing, but horizontal entrainment of oxygenated waters and vertical mixing of oxidized manganese into sulfidic waters may occur near the Bosphorus Strait inlet. Manganese and iron oxides likely oxidize hydrogen sulfide near the chemocline, resulting in the decrease in H2S concentrations as one approaches the chemocline from below.
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Renalase has been claimed to degrade catecholamines like adrenaline (epinephrine) and noradrenaline (norepinephrine) in the blood circulation. Dr. Gary Desir's laboratory at Yale School of Medicine discovered and named renalase in 2005 suggest that the human kidney releases this protein into the bloodstream to regulate blood pressure (in addition to other possible, as yet undiscovered, functions). Whether renalase actually oxidizes catecholamine substrates has been widely disputed. The primary evidence for catecholamine oxidation is the detection of H2O2, however catecholamines emanate H2O2 in the presence of O2 in a natural decomposition reaction. In 2013, renalase was claimed to oxidize α-NADH (the normal form of NADH is the β anomer) to β-NAD, with concomitant reduction of O2 (dioxygen) to H2O2 (hydrogen peroxide).
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For ideal health and decreased risk of low-grade chronic inflammation, it is more beneficial to have a lower ratio versus a higher one. Omega-3 fatty acids have anti-inflammatory properties and therefore need to be supplemented in a closer ratio to omega-6's which are more inflammatory. Out of all of the omega-3 fatty acids that could be used, the most potent are found in fish oil in the forms of EPA and DHA, these have the highest immunomodulatory activities. Omega-3 fatty acids tend to increase antioxidant requirements because they oxidize so rapidly, therefore when they are in a closer ratio to omega-6 fatty acids, as recommended, antioxidants must also be supplemented in the diet.
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Lead quenches the pyrolysed radicals and thus kills the radical chain reaction that would sustain a cool flame, preventing it from disturbing the smooth ignition of the hot flame front. Lead itself is the reactive antiknock agent, and TEL serves as a gasoline-soluble lead carrier. When (CHCH)Pb burns, it produces not only carbon dioxide and water, but also lead: This lead can oxidize further to give species such as lead(II) oxide: Pb and PbO would quickly over-accumulate and destroy an engine. For this reason, the lead scavengers 1,2-dibromoethane and 1,2-dichloroethane are used in conjunction with TEL—these agents form volatile lead(II) bromide and lead(II) chloride, respectively, which are flushed from the engine and into the air.
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Iced tencha tea Tencha refers to green tea leaves that have not yet been ground into fine powder as matcha, as the leaves are instead left to dry rather than be kneaded. Since the leaves' cell walls are still intact, brewing tencha tea results in a pale green brew, which has a more mellow taste compared to other green tea extracts, and only the highest grade of tencha leaves can brew to its fullest flavor. Tencha leaves are half the weight of other tea leaves such as gyokuro and sencha, so most tencha brews require double the number of leaves. About an hour is needed to grind 40 to 70 g of tencha leaves into matcha, and matcha does not retain its freshness as long as tencha in powder form because powder begins to oxidize.
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Yeast reduction The Baeyer–Villiger oxidation is another example of a biocatalytic reaction. In one study a specially designed mutant of Candida antarctica was found to be an effective catalyst for the Michael addition of acrolein with acetylacetone at 20 °C in absence of additional solvent. Another study demonstrates how racemic nicotine (mixture of S and R-enantiomers 1 in scheme 3) can be deracemized in a one-pot procedure involving a monoamine oxidase isolated from Aspergillus niger which is able to oxidize only the amine S-enantiomer to the imine 2 and involving an ammonia–borane reducing couple which can reduce the imine 2 back to the amine 1. In this way the S-enantiomer will continuously be consumed by the enzyme while the R-enantiomer accumulates.
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A. thiooxidans uses elemental sulfur as its primary energy source and oxidizes it by the sulfide-quinone reductase and sox pathways. Sulfur is oxidized to sulfuric acid by A. thiooxidans and the energy liberated is used for growth and maintenance. In addition to sulfur, A. thiooxidans can use thiosulfate or tetrathionate as sources of energy, but growth in a liquid medium on thiosulfate is slow, generally taking about 10 to 12 days under favorable conditions as opposed to only 4 to 5 days for growth on elemental sulfur, as demonstrated by the change in pH and turbidity. A. thiooxidans is incapable of oxidizing iron or pyrite, but it has been shown to grow on sulfur from pyrite when cocultured with the bacterium Leptospirillum ferrooxidans, a species that can oxidize iron but not sulfur.
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First, the sulfide concentrate is roasted in air to oxidize the lead sulfide: : 2 PbS(s) + 3 O2(g) → 2 PbO(s) + 2 SO2(g)↑ As the original concentrate was not pure lead sulfide, roasting yields not only the desired lead(II) oxide, but a mixture of oxides, sulfates, and silicates of lead and of the other metals contained in the ore. This impure lead oxide is reduced in a coke-fired blast furnace to the (again, impure) metal: : 2 PbO(s) + C(s) → 2 Pb(s) + CO2(g)↑ Impurities are mostly arsenic, antimony, bismuth, zinc, copper, silver, and gold. Typically they are removed in a series of pyrometallurgical processes. The melt is treated in a reverberatory furnace with air, steam, and sulfur, which oxidizes the impurities except for silver, gold, and bismuth.
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Initial evidence for a chemoautotrophic symbiosis in R. pachyptila came from microscopic and biochemical analyses showing Gram-negative bacteria packed within a highly vascularized organ in the tubeworm trunk called the trophosome. Additional analyses involving stable isotope, enzymatic, and physiological characterizations herbely confirmed that the end symbionts of R. pachyptila oxidize reduced-sulfur compounds to synthesize ATP for use in autotrophic carbon fixation through the Calvin cycle. The host tubeworm enables the uptake and transport of the substrates required for thioautotrophy, which are HS−, O2, and CO2, receiving back a portion of the organic matter synthesized by the symbiont population. The adult tubeworm, given its inability to feed on particulate matter and its entire dependency on its symbionts for nutrition, the bacterial population is then the primary source of carbon acquisition for the symbiosis.
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In general, amino radicals are highly reactive and short lived; however, this is not the case when reacted with some organic molecules. Relative reactivities of the amino radical with several organic compounds have been reported, but the absolute rate constants for such reactions remain unknown. In reaction 1, it was hypothesized that the amino radical might possibly react with NH3 more rapidly than OH and might oxidize to produce the amino radical in acid solutions, given that radicals are stronger oxidants than OH. In order to test this, sulfate and phosphate radical anions were used. The sulfate and phosphate radical anions were found to react more slowly with NH3 than does the amino radical and they react with ammonia by hydrogen abstraction and not by electron transfer oxidation.
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In the absorbent glass mat design, or AGM for short, the separators between the plates are replaced by a glass fibre mat soaked in electrolyte. There is only enough electrolyte in the mat to keep it wet, and if the battery is punctured the electrolyte will not flow out of the mats. Principally the purpose of replacing liquid electrolyte in a flooded battery with a semi-saturated fiberglass mat is to substantially increase the gas transport through the separator; hydrogen or oxygen gas produced during overcharge or charge (if the charge current is excessive) is able to freely pass through the glass mat and reduce or oxidize the opposing plate respectively. In a flooded cell the bubbles of gas float to the top of the battery and are lost to the atmosphere.
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Because XO is a superoxide-producing enzyme, with general low specificity, it can be combined with other compounds and enzymes and create reactive oxidants, as well as oxidize other substrates. Bovine xanthine oxidase (from milk) was originally thought to have a binding site to reduce cytochrome c with, but it has been found that the mechanism to reduce this protein is through XO's superoxide anion byproduct, with competitive inhibition by carbonic anhydrase. Another reaction catalyzed by xanthine oxidase is the decomposition of S-Nitrosothiols (RSNO), a reactive nitrogen species, to nitric oxide (NO), which reacts with a superoxide anion to form peroxynitrite under aerobic conditions. XO has also been found to produce the strong one-electron oxidant carbonate radical anion from oxidation with acetaldehyde in the presence of catalase and bicarbonate.
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RC models LiPo batteries are now almost ubiquitous when used to power radio-controlled aircraft, radio- controlled cars and large scale model trains, where the advantages of lower weight and increased capacity and power delivery justify the price. Test reports warn of the risk of fire when the batteries are not used in accordance with the instructions. LiPo packs also see widespread use in airsoft, where their higher discharge currents and better energy density compared to more traditional NiMH batteries has very noticeable performance gain (higher rate of fire). The high discharge currents do damage the switch contacts due to arcing (causing the contacts to oxidize and often deposit carbon), so it is advised to either use a solid-state MOSFET switch or clean the trigger contacts regularly.
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Alpha-methylacyl-CoA racemase (AMACR) is an enzyme that in humans is encoded by the AMACR gene. AMACR catalyzes the following chemical reaction: :(2R)-2-methylacyl-CoA \rightleftharpoons (2S)-2-methylacyl-CoA In mammalian cells, the enzyme is responsible for converting (2R)-methylacyl-CoA esters to their (2S)-methylacyl-CoA epimers and known substrates, including coenzyme A esters of pristanic acid (mostly derived from phytanic acid, a 3-methyl branched-chain fatty acid that is abundant in the diet) and bile acids derived from cholesterol. This transformation is required in order to degrade (2R)-methylacyl-CoA esters by β-oxidation, which process requires the (2S)-epimer. The enzyme is known to be localised in peroxisomes and mitochondria, both of which are known to β-oxidize 2-methylacyl-CoA esters.
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More recently, it has been discovered that some organic and bio-inspired molecules, such as the chelator called 3,4,3-LI(1,2-HOPO), can also oxidize Bk(III) and stabilize Bk(IV) under mild conditions. is then extracted with ion exchange, extraction chromatography or liquid-liquid extraction using HDEHP (bis-(2-ethylhexyl) phosphoric acid), amines, tributyl phosphate or various other reagents. These procedures separate berkelium from most trivalent actinides and lanthanides, except for the lanthanide cerium (lanthanides are absent in the irradiation target but are created in various nuclear fission decay chains). A more detailed procedure adopted at the Oak Ridge National Laboratory was as follows: the initial mixture of actinides is processed with ion exchange using lithium chloride reagent, then precipitated as hydroxides, filtered and dissolved in nitric acid.
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Based on a discovery made in the 1990s at the Wisconsin Center for Space Automation and Robotics where Researchers, with the help of the Space Product Development Program at Marshall Space Flight Center, were trying to find a way to eliminate ethylene that accumulates around plants growing in spacecraft and then found a solution: light-induced oxidation. When UV light hits titanium dioxide, it frees electrons that turn oxygen and moisture into charged particles that oxidize air contaminants such as volatile organic compounds, turning them into carbon dioxide and water. This air scrubber also eliminates other airborne organic compounds and neutralized bacteria, viruses, and molds. An air scrubber with light-induced oxidation can cleans air, surfaces and clothes and nearly 30 Major League Baseball teams now have this scrubber technology in their facilities.
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IBX is also available as silica gel or polystyrene bound IBX. In many applications, IBX is replaced by Dess–Martin periodinane which is more soluble in common organic solvents. A sample reaction is an IBX oxidation used in the total synthesis of eicosanoid: More and Finney and Van Arman have demonstrated that common organic solvents are suitable for many IBX oxidations, despite its low solubility, and in fact may simplify product purification. :IBX oxidation of alcohol to aldehyde key data: a) IBX, DMSO, THF, 4h, 94% chemical yield (Mohapatra, 2005) In 2001, K. C. Nicolaou and co- workers published a series of papers in the Journal of the American Chemical Society demonstrating, among other transformations, the use of IBX to oxidize primary and secondary benzylic carbons to aromatic aldehydes and ketones, respectively.
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The Prilezhaev reaction involves the conversion of an alkene to an epoxide using a peracid as the oxidant and was first reported in 1909. The reaction has been used as the final step of the synthesis of scopine, a tropane alkaloid. In this approach, a [4+3] cycloaddition mediated by diiron nonacarbonyl is used to construct the bicyclic skeleton, the hydroxyl functional group is then introduced by diastereoselective reduction of the ketone with diisobutylaluminum hydride, and the preparation completed with a Prilezhaev trifluoroperacetic acid epoxidation. 600px The high reactivity of trifluoroperacetic acid relative to other peroxy acids allows it to successfully oxidize relatively electron-poor alkenes such as 1-hexene and α,β-unsaturated esters such as methyl methacrylate, substrates that are generally resistant to peroxy-acid epoxidation.
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Oxidation can be achieved by heating the alcohol with an acidified solution of potassium dichromate. In this case, excess dichromate will further oxidize the aldehyde to a carboxylic acid, so either the aldehyde is distilled out as it forms (if volatile) or milder reagents such as PCC are used. :[O] + CH3(CH2)9OH → CH3(CH2)8CHO + H2O Oxidation of primary alcohols to form aldehydes can be achieved under milder, chromium-free conditions by employing methods or reagents such as IBX acid, Dess–Martin periodinane, Swern oxidation, TEMPO, or the Oppenauer oxidation. Another oxidation route significant in industry is the Wacker process, whereby ethylene is oxidized to acetaldehyde in the presence of copper and palladium catalysts (acetaldehyde is also produced on a large scale by the hydration of acetylene).
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Catalytic bead sensors are commonly used to measure combustible gases that present an explosion hazard when concentrations are between the lower explosion limit (LEL) and upper explosion limit (UEL). Active and reference beads containing platinum wire coils are situated on opposite arms of a Wheatstone bridge circuit and electrically heated, up to a few hundred degrees C. The active bead contains a catalyst that allows combustible compounds to oxidize, thereby heating the bead even further and changing its electrical resistance. The resulting voltage difference between the active and passive beads is proportional to the concentration of all combustible gases and vapors present. The sampled gas enters the sensor through a sintered metal frit, which provides a barrier to prevent an explosion when the instrument is carried into an atmosphere containing combustible gases.
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For propellants to oxidize and burn rapidly and effectively, the combustible ingredients must be reduced to the smallest possible particle sizes, and be as thoroughly mixed as possible. Once mixed, however, for better results in a gun, makers discovered that the final product should be in the form of individual dense grains that spread the fire quickly from grain to grain, much as straw or twigs catch fire more quickly than a pile of sawdust. Because the dry powdered ingredients must be mixed and bonded together for extrusion and cut into grains to maintain the blend, size reduction and mixing is done while the ingredients are damp, usually with water. After 1800, instead of forming grains by hand or with sieves, the damp mill-cake was pressed in molds to increase its density and extract the liquid, forming press-cake.
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Edward Frankland, a distinguished chemist, who demonstrated the possibility of chemically treating sewage in the 1870s It was not until the late 19th century that it became possible to treat the sewage by biologically decomposing the organic components through the use of microorganisms and removing the pollutants. Land treatment was also steadily becoming less feasible, as cities grew and the volume of sewage produced could no longer be absorbed by the farmland on the outskirts. Edward Frankland conducted experiments at the sewage farm in Croydon, England, during the 1870s and was able to demonstrate that filtration of sewage through porous gravel produced a nitrified effluent (the ammonia was converted into nitrate) and that the filter remained unclogged over long periods of time. This established the then revolutionary possibility of biological treatment of sewage using a contact bed to oxidize the waste.
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Chemical oxidation of the copper ore with ferric (Fe3+) ions formed by the microbial oxidation of ferrous ions (derived from the oxidation of pyrite). Three possible reactions for the oxidation of copper ore are: :Cu2S + 1/2 O2 \+ 2 H+ → CuS + Cu2+ \+ H2O :CuS + 2 O2 → Cu2+ \+ SO42− :CuS + 8 Fe3+ \+ 4 H2O → Cu2+ \+ 8 Fe2+ \+ SO42− \+ 8 H+ The copper metal is then recovered by using Fe0 from steel cans: :Fe0 \+ Cu2+ → Cu0 \+ Fe2+ The temperature inside the leach dump often rises spontaneously as a result of microbial activities. Thus, thermophilic iron-oxidizing chemolithotrophs such as thermophilic Acidithiobacillus species and Leptospirillum and at even higher temperatures the thermoacidophilic archaeon Sulfolobus (Metallosphaera sedula) may become important in the leaching process above 40 °C. Similarly to copper, Acidithiobacillus ferrooxidans can oxidize U4+ to U6+ with O2 as electron acceptor.
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Therefore, it may be speculated the metabolism of these bacteria, being either chemolithoautotrophic or mixotrophic, is strongly dependent on the uptake of reduced sulfur compounds, which occurs in many habitats only in deeper regions at or below the OATZ due to the rapid chemical oxidation of these reduced chemical species by oxygen or other oxidants in the upper layers. Microorganisms belonging to the genus Thioploca, for example, use nitrate, which is stored intracellularly, to oxidize sulfide, and have developed vertical sheaths in which bundles of motile filaments are located. It is assumed that Thioploca uses these sheathes to move efficiently in a vertical direction in sediment, thereby accumulating sulfide in deeper layers and nitrate in upper layers. For some MTB, it might also be necessary to perform excursions to anoxic zones of their habitat to accumulate reduced sulfur compounds.
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Combination happened in a similar fashion as phenol and formaldehyde molecules react to urea-formaldehyde resins, but kerogen formation occurred in a more complex manner due to a bigger variety of reactants. The total process of kerogen formation from the beginning of anaerobic decay is called diagenesis, a word that means a transformation of materials by dissolution and recombination of their constituents. ;Transformation of kerogen into fossil fuels: Kerogen formation continued to the depth of about 1 km from the Earth's surface where temperatures may reach around 50 °C. Kerogen formation represents a halfway point between organic matter and fossil fuels: kerogen can be exposed to oxygen, oxidize and thus be lost or it could be buried deeper inside the Earth's crust and be subjected to conditions which allow it to slowly transform into fossil fuels like petroleum.
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Cells of one type may release the 5(S)-HETE that they make to nearby cells of a second type which then oxidize the 5(S)-HETE to 5-oxo-ETE. This transcellular production typically involves the limited variety of cell types that express active 5-lipoxygenase, lack HEDH activity because of their high levels of NADPH compared to NADP+ levels, and therefore accumulate 5(S)-HETE, not 5-oxo-ETE, upon stimulation. This 5(S)-ETE can leave these cells, enter various cell types that possess 5-HEDH activity along with lower NADPH to NADP+ levels, and thereby be converted to 5-oxo-ETE. Transcellular production of 5-oxo-eicosatetraenoates has been demonstrated in vitro with human neutrophils as the 5(S)-HETE producing cells and human PC-3 prostate cancer cells, platelets, and monocyte- derived dendritic cells as the oxidizing cells.
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The principal purpose of doing this is to purify the interior of the tube before the tube is sealed off so that when it is operated, these gases and impurities are not driven off and released by the plasma and the heat generated into the sealed tube, which would quickly burn the metal cathodes and mercury droplets (if pumped with argon/mercury) and oxidize the interior gases and cause immediate tube failure. The more thorough the purification of the tube is, the longer lasting and stable the tube will be in actual operation. Once these gases and impurities are liberated under pre-filling bombardment into the tube interior they are quickly evacuated by the pump. While still attached to the manifold, the tube is allowed to cool while pumping down to the lowest pressure the system can achieve.
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In thermophilic composting bacteria that thrive at temperatures of oxidize (break down) waste into its components, some of which are consumed in the process, reducing volume and eliminating potential pathogens. To destroy pathogens, thermophilic composting must heat the compost pile sufficiently, or enough time (1–2 years) must elapse since fresh material was added that biological activity has had the same pathogen removal effect. One guideline claims that pathogen levels are reduced to a safe level by thermophilic composting at temperatures of 55 °C for at least two weeks or at 60 °C for one week. An alternative guideline claims that complete pathogen destruction may be achieved already if the entire compost heap reaches a temperature of for one hour, for one day, for one week or for one month, although others regard this as overly optimistic.
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An MDC is constructed similarly to a microbial fuel cell by including two chambers with two electrodes, an anode and a cathode, in addition to both a third chamber separated by an anion exchange membrane (AEM) and cation exchange membrane (CEM), and a peripheral, external circuit that is responsible for aerobic and anaerobic processes at each respective electrode. Organic matter from the sludge proliferates in the anode chamber and creates a biofilm that generates an electric current. The biofilm thus begins to oxidize the pollutants in the sludge by strictly adhering to the anode, freeing both electrons and protons from the bio-sludge, creating a current of atoms that are collected by the electrodes through circuit transportation. Electrical current is produced by the potential difference generated between the anode and cathode due to the aerobic nature of the cathode chamber.
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A SCOBY used for brewing kombucha. Kombucha co-culture with SCOBY biofilm SCOBY is the commonly used acronym for "symbiotic culture of bacteria and yeast," and is formed after the completion of a unique fermentation process of lactic acid bacteria (LAB), acetic acid bacteria (AAB), and yeast to form several sour foods and beverages such as kombucha and kimchi. Beer and wine also undergo fermentation with yeast, but the lactic acid bacteria and acetic acid bacteria components unique to SCOBY are usually viewed as a source of spoilage rather than a desired addition. Both LAB and AAB enter on the surface of barley and malt in beer fermentation and grapes in wine fermentation; LAB lower the pH of the beer while AAB take the ethanol produced from the yeast and oxidize it further into vinegar, resulting in a sour taste and smell.
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In particular, she found that sites with a high diversity of methanotrophs, or bacteria that oxidize methane, have more stable levels of methane consumption, which suggested that managing lands to maintain methanotroph diversity could be a good way of managing levels of this greenhouse gas. To do facilitate this work, Teal developed bioinformatics tools to remove systematic artifacts for more precise metagenomics analyses. Following her fellowship, Teal became a Research Associate and later Assistant Professor at Michigan State University in microbiology and molecular biology. Her lab was part of the BEACON Center for the Study of Evolution in Action, a National Science Foundation research center that brings together biologists, computer scientists, and engineers to study evolution in real time and use findings from the natural world to solve real-world problems—from disaster management to engineering safer cars.
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The operator would manually switch the ignition over to magneto operation for high speed operation. To provide high voltage for the spark from the low voltage batteries, a 'tickler' was used, which was essentially a larger version of the once widespread electric buzzer. With this apparatus, the direct current passes through an electromagnetic coil which pulls open a pair of contact points, interrupting the current; the magnetic field collapses, the spring-loaded points close again, the circuit is reestablished, and the cycle repeats rapidly. The rapidly collapsing magnetic field, however, induces a high voltage across the coil which can only relieve itself by arcing across the contact points; while in the case of the buzzer this is a problem as it causes the points to oxidize and/or weld together, in the case of the ignition system this becomes the source of the high voltage to operate the spark plugs.
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The chemical processes that affect the removal are dependent on the ability of atmospheric chemistry to oxidize the carbonaceous component of the smoke, via reactions with oxidative species such as ozone and nitrogen oxides, both of which are found at all levels of the atmosphere,Distribution & concentration (2) Dr. Elmar Uherek – Max Planck Institute for Chemistry Mainz, April 6, 2004Atmospheric effects and societal consequences of regional scale nuclear conflicts and acts of individual nuclear terrorism Atmos Chem Phys 7:1973–2002, p. 1999. At one time it was thought that carbonaceous aerosol might be consumed by reactions with ozone (Stephens et al., 1989) and other oxidants, reducing the lifetime of soot at stratospheric altitudes. However recent data shows that the reaction probability for such loss of soot is about 10^-11 so it is not an important process on times scales of several years (Kamm et al.
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Over time, the very high heat of incineration causes the metal to oxidize and rust, and eventually the barrel itself is consumed by the heat and must be replaced. The private burning of dry cellulosic/paper products is generally clean-burning, producing no visible smoke, but plastics in the household waste can cause private burning to create a public nuisance, generating acrid odors and fumes that make eyes burn and water. Most urban communities ban burn barrels and certain rural communities may have prohibitions on open burning, especially those home to many residents not familiar with this common rural practice. in the United States, private rural household or farm waste incineration of small quantities was typically permitted so long as it is not a nuisance to others, does not pose a risk of fire such as in dry conditions, and the fire does not produce dense, noxious smoke.
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It is very difficult to oxidize polonium beyond Po(IV); for example, the only hexahalide of polonium is the hexafluoride, PoF6, and fluorine is already the most electronegative element (though polonium hexaiodide was once reportedly formed in the vapour phase, it immediately decomposed). However, the difficulty in obtaining polonium trioxide and polonates (containing the anion, analogous to sulfate, selenate, and tellurate) by direct oxidation of Po(IV) compounds may be due to the fact that polonium-210, while the most easily available isotope of polonium, is strongly radioactive. Similar work with curium shows that it is easier to achieve higher oxidation states with longer-lived isotopes; thus, it may be easier to obtain Po(VI) (especially polonium trioxide) using the longer-lived polonium-208 or polonium-209. It has been suggested that Po(VI) might be more stabilized in anions such as or , like other high oxidation states.
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In contrast, LaserDisc playback quality is highly dependent on hardware quality, and major variances in picture quality appear between different makers and models of LD players, even when tested on a low to mid-range television. The obvious benefits of using high quality equipment has helped keep demand for some players high, thus also keeping pricing for those units comparably high: in the 1990s, notable players sold for anywhere from US$200 to well over $1,000, while older and less desirable players could be purchased in working condition for as little as $25. Many early LDs were not manufactured properly; the adhesive used contained impurities that were able to penetrate the lacquer seal layer and chemically attack the metalized reflective aluminium layer, causing it to oxidize and lose its reflective characteristics. This was a problem that was termed "laser rot" among LD enthusiasts, also called "color flash" internally by LaserDisc-pressing plants.
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SO2, sulphur dioxide or dioxide of sulphur is used in all winemaking operations from harvesting to packaging. It plays a protective role in the wine against the phenomena of oxidation, oxidase enzyme action (enzymes that oxidize the polyphenols in wine), and the control of microbial populations in yeasts and bacteria (antiseptic effect).Inputs in Oenology: SO2 or Sulphur Dioxide, Institut français de la vigne et du vin, consulted on 9 January 2011 The maximum allowable doses depend on the sugar content of the wine: the residual sugar is susceptible to attack by microorganisms which would cause a restart of fermentation. In France the dose is limited to 150 mg/litre for Vin de Pays (country wines), 185 mg/l for Sparkling wines, 200 mg/l for Fortified wines, 200 mg/l for dry white wines, 250 mg/l for white wines with residual sugar greater than 5 g/litre (Moelleux wines), and 300 mg/l for liquoreux sweet wines.
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DPS are highly symmetrical dodecameric proteins of 20 kDa characterized from a shell-like structure of 2:3 tetrahedral symmetry assembled from identical subunits with an external diameter of ~ 9 nm and a central cavity of ~ 4.5 nm in diameter. Dps proteins belong to the ferritin superfamily and the DNA protection is afforded by means of a double mechanism: The first was discovered in Escherichia coli Dps in 1992 and has given the name to the protein family; during stationary phase, Dps binds the chromosome non-specifically, forming a highly ordered and stable dps-DNA co-crystal within which chromosomal DNA is condensed and protected from diverse damages. The lysine-rich N-terminus is required for self- aggregation as well as for Dps-driven DNA condensation. The second mode of protection is due to the ability of Dps proteins to bind and oxidize Fe(II) at the characteristic, highly conserved intersubunit ferroxidase center.
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The redox reaction in a Leclanché cell involves the two following half-reactions: :– anode (oxidation of Zn): Zn → Zn2+ \+ 2e− :– cathode (reduction of Mn(IV)): 2 MnO2 \+ 2NH4+ \+ 2e− → 2 MnO(OH) + 2 NH3 The chemical process which produces electricity in a Leclanché cell begins when zinc atoms on the surface of the anode oxidize, i.e. they give up both their valence electrons to become positively charged Zn2+ ions. As the Zn2+ ions move away from the anode, leaving their electrons on its surface, the anode becomes more negatively charged than the cathode. When the cell is connected in an external electrical circuit, the excess electrons on the zinc anode flow through the circuit to the carbon rod, the movement of electrons forming an electric current. As the current travels around the circuit, when the electrons enter the cathode (carbon rod), they combine with manganese dioxide (MnO2) and water (H2O), which react with each other to produce manganese oxide (Mn2O3) and negatively charged hydroxide ions.
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When titanium dioxide is exposed to ultraviolet radiation from sunlight, it absorbs the radiation and electron excitation occurs. The following reactions then occur on the surface of the titanium dioxide crystals: Photolysis of water: : H2O → H+ \+ OH (hydroxyl radical) + e− : O2 \+ e− → O2− (a superoxide ion) The overall reaction is therefore: : H2O + O2 → H+ \+ O2− \+ OH The hydroxyl radical is a powerful oxidizing agent and can oxidize nitrogen dioxide to nitrate ions: : NO2 \+ OH → H+ \+ NO3− The superoxide ion is also able to form nitrate ions from nitrogen monoxide: : NO + O2− → NO3− The oxidation of NOx to nitrate ions occurs very slowly under normal atmospheric conditions because of the low concentrations of the reactions. The photochemical oxidation with the aid of titanium dioxide is much faster because of the energy absorbed by the coating on the block and also because the reactants are held together on the surface of the block. The reaction using titanium dioxide shows a greater oxidizing power than most other metal-based catalysts.
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The casting section receives completed lines from the assembler, and uses these to cast the type slugs that are the product of the linotype machine. The casting section is automatic: once it is activated by the operator sending a completed line by raising the casting lever, a series of cams and levers move the matrices through the casting section and control the sequence of steps that produce the slug. The casting material is an alloy of lead (85%), antimony (11%), and tin (4%),"Typesetting" film in the Internet Archive and produces a one-piece casting slug capable of 300,000 impressions before the casting begins to develop deformities and imperfections, and the type must be cast again. The continuous heating of the molten alloy causes the tin and antimony in the mixture to rise to the top and oxidize along with other impurities into a substance called "dross" which has to be skimmed off.
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Nitric acid reacts with most metals, but the details depend on the concentration of the acid and the nature of the metal. Dilute nitric acid behaves as a typical acid in its reaction with most metals. Magnesium, manganese, and zinc liberate H2: :Mg + 2 HNO3 → Mg(NO3)2 \+ H2 (Magnesium nitrate) :Mn + 2 HNO3 → Mn(NO3)2 \+ H2 (Manganese(II) nitrate) Nitric acid can oxidize non-active metals such as copper and silver. With these non-active or less electropositive metals the products depend on temperature and the acid concentration. For example, copper reacts with dilute nitric acid at ambient temperatures with a 3:8 stoichiometry: :3 Cu + 8 HNO3 → 3 Cu2+ \+ 2 NO + 4 H2O + 6 The nitric oxide produced may react with atmospheric oxygen to give nitrogen dioxide. With more concentrated nitric acid, nitrogen dioxide is produced directly in a reaction with 1:4 stoichiometry: :Cu + 4 H+ \+ 2 → Cu2+ \+ 2 NO2 \+ 2 H2O Upon reaction with nitric acid, most metals give the corresponding nitrates.
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For typical raw waters feeding into the front end of an UPW purification system the raw water can contain TOC levels between 0.7 mg/L to 15 mg/L and require a robust oxidation method that can insure there is enough oxygen available to completely convert all the carbon atoms in the organic molecules into CO. Robust oxidation methods that supply sufficient oxygen include the following methods; Ultraviolet light (UV) & persulfate, heated persulfate, combustion, and super critical oxidation. Typical equations showing persulfate generation of hydroxyl radicals follows. SO + hν (254 nm) → 2 SO• and SO • + HO → HSO + OH • When the organic concentration is less than 1 mg/L as TOC and the water is saturated with oxygen UV light is sufficient to oxidize the organics to CO, this is a simpler oxidation method. The wavelength of the UV light for the lower TOC waters must be less than 200 nm and is typically 184 nm generated by a low pressure Hg vapor lamp.
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The cytochrome P450s (P450s) are xenobiotic-metabolizing membrane- bound heme-containing enzymes that use molecular oxygen and electrons from NADPH cytochrome P450 reductase to oxidize their substrates. CYP2B4, a member of the cytochrome P450 family is the only protein within this family, whose X-ray structure in both open 11 and closed form 12 is published. The comparison of the open and closed structures of CYP2B4 structures reveals large-scale conformational rearrangement between the two states, with the greatest conformational change around the residues 215-225, which is widely open in ligand-free state and shut after ligand binding; and the region around loop C near the heme. HB Plot and structure of Cytochrome P450 2B4 in closed form Examining the HB plot of the closed and open state of CYP2B4 revealed that the rearrangement of tertiary hydrogen bonds was in excellent agreement with the current knowledge of the cytochrome P450 catalytic cycle.
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This idea met skepticism from meteoriiticists and cosmochemists because it contradicted a commonly accepted rule of thumb that held that the abundance of carbon must exceed that of oxygen (written C>O) in order for carbon to condense. Clayton advocated that supernova carbon stardust (which in 1977 he had namedDonald D. Clayton, "Precondensed matter: Key to the early solar system", Moon & Planets 19, 109(1978) SUNOCONs, an acronym for SUperNOva CONdensates) could therefore assemble within hot supernova C+O gases containing more oxygen than carbon and nothing else. Rather than a specialist's chemical detail, this is a profound conclusion for astrophysics because it partly explains the large amounts of dust created by supernovae in the early universe. Meteoritic chemists to whom his 1998-99 Lunar and Planetary Science Conference papers were addressed doubted that possibility on intuitive but erroneous chemical grounds, believing that abundant hot oxygen gas would oxidize all carbon atoms leaving them trapped within chemically inert CO molecules—an expectation that holds true in ordinary stars.
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The technique for producing black tea was first developed during the late Ming Dynasty in Wuyishan, Fujian, either resulting from the over-oxidation of tea- leaves during the manufacture of oolong tea or indirectly from the methods of manufacturing green and white teas. In the early 1600s, tea producers in the Wuyi Mountains began kneading the sun-withered tea leaves to macerate them, then allowed them to dry under the sun, thus reaching full oxidation and producing Gongfu black tea (工夫紅茶). When there was insufficient sun and temperatures were low, the withered leaves would be processed indoors in warmed rooms and allowed to fully oxidize, then smoked dry over pine fires thus producing lapsang souchong. According to oral traditions of the region, the discovery of Lapsang Souchong processing was due to military troops passing through a Wuyishan tea factory during the last years of the Ming Dynasty, causing delays to tea leaf processing thus resulting in a completely oxidized leaf that the producer salvaged by drying over a fire built from pine branches.
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Nomenclature of the aldaric acids is based on the sugars from which they are derived; for example, glucose is oxidized to glucaric acid and xylose to xylaric acid. Unlike their parent sugars, aldaric acids have the same functional group at both ends of their carbon chain; therefore, two different sugars can yield the same aldaric acid (this can be understood by looking at the Fischer projection of a sugar upside down—with normal aldoses, this is a different compound due to the aldehyde function at the top and the hydroxyl function at the bottom, but with aldaric acids, there is a carboxylic acid function on both ends, so upside down and right side up do not matter). For example, D-glucaric acid and L-gularic acid are the same compound (but the first name is preferred, because of D\- prefix). A consequence of this is that some aldaric acids are meso forms with no optical activity despite their multiple chiral centers—this occurs if a sugar and its enantiomer oxidize to the same aldaric acid.
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Photosynthesis and cellular respiration are distinct processes, as they take place through different sequences of chemical reactions and in different cellular compartments. The general equation for photosynthesis as first proposed by Cornelis van Niel is therefore: : + + → + + Since water is used as the electron donor in oxygenic photosynthesis, the equation for this process is: : + + → + + This equation emphasizes that water is both a reactant in the light-dependent reaction and a product of the light-independent reaction, but canceling n water molecules from each side gives the net equation: : + + → + Other processes substitute other compounds (such as arsenite) for water in the electron-supply role; for example some microbes use sunlight to oxidize arsenite to arsenate:Anaerobic Photosynthesis, Chemical & Engineering News, 86, 33, August 18, 2008, p. 36 The equation for this reaction is: : + + → + (used to build other compounds in subsequent reactions) Photosynthesis occurs in two stages. In the first stage, light-dependent reactions or light reactions capture the energy of light and use it to make the energy-storage molecules ATP and NADPH.
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Scheme 1 presents an overview of the first step, the creation of a 13 membered ring orifice on the fullerene surface. A 1,2,4-triazine 2 is fitted with two phenyl groups and a pyridine group for reasons of solubility and reacted in 1,2-dichlorobenzene with pristine C60 fullerene 2 in a Diels- Alder reaction at high temperature and for an extended reaction time. In this reaction nitrogen is expulsed and an 8-membered ring is formed (3). This orifice is further extended by reaction with singlet oxygen in carbon tetrachloride which causes one of the ring alkene groups to oxidize to a ketone. The 12-ring is extended to a 13-ring by reaction with elemental sulfur in presence of tetrakis(dimethylamino)ethylene. Scheme 1. Endohedral hydrogen fullerene overview The proposed reaction mechanism is depicted in a plat surface rendition in scheme 2. In the first step the triazine reacts with the fullerene in a Diels-Alder reaction. In the second step nitrogen is expulsed from the DA adduct 2 resulting in the formation of a fused aza-cyclohexadiene ring followed by a [4+4]cycloaddition to an intermediate 4 with two cyclopropane rings.
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Unfortunately, this connection resulted in their damnation, and Yū became a homicidal maniac as a result. Not only that, but he also became a massively powerful Qwaser with the element, oxygen, which allowed him to walk in the air with impunity, create pressures of enormous proportions, air currents capable of large destruction and more devious acts, such as suffocating anyone he wished with no more than a thought or incapacitating them by saturating their surroundings with oxygen. His sister, Aoi, contacted Sasha and begged him to kill Yū and stop his rampage, though initially both him and Ekaterina were no match for someone who could oxidize their metal with a whim, rendering them powerless. However, when Sasha fought him for one last time it was revealed that there was no Yū, as he died long ago, it was Aoi all the time: deemed unfit for combat as a Qwaser, the Adepts wanted to use her as a supply of Soma, and when she was about to be assaulted, she unleashed her powers in self-defense, slaughtering her assailant only to discover, to her horror, that it was her brother.
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Even though the superoxide and the hydrogen peroxide radicals are toxic in their own right, they become potentially more toxic when they interact to form the hydroxyl radical (OH•). This proceeds through the iron and copper catalyzed Haber–Weiss reaction: O2− \+ Fe3+ ↔ O2 \+ Fe2+ H2O2 \+ Fe2+ ↔ Fe3+ \+ OH• + OH− Since iron and copper are present in coastal waters, the hydroxyl radical could be formed by reactions with either of the, and, in fact, their oxidation does result in significant sources of hydroxyl radicals in the ocean. The hydroxyl radical is the most unstable of the ROS (lifetime of 10−7seconds), reacting with many inorganic and organic species in the surrounding environment at rates near the diffusion limit (rate constants of 108 -1010 L mol−1 sec−1). In seawater, the radical is removed as a result of reactions with bromide ions, while in fresh water it reacts principally with bicarbonate and carbonate ions. Because it has such a high reactivity, day time concentrations in surface waters of the hydroxyl radical are generally very low (10−19 to 10−17 M). The hydroxyl radical can oxidize membrane lipids and cause nucleic acids and proteins to denature.
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Chlorinated disinfection agents such as chlorine and monochloramine are strong oxidizing agents introduced into water in order to destroy pathogenic microbes, to oxidize taste/odor-forming compounds, and to form a disinfectant residual so water can reach the consumer tap safe from microbial contamination. These disinfectants may react with naturally present fulvic and humic acids, amino acids, and other natural organic matter, as well as iodide and bromide ions, to produce a range of DBPs such as the trihalomethanes (THMs), haloacetic acids (HAAs), bromate, and chlorite (which are regulated in the US), and so- called "emerging" DBPs such as halonitromethanes, haloacetonitriles, haloamides, halofuranones, iodo-acids such as iodoacetic acid, iodo-THMs (iodotrihalomethanes), nitrosamines, and others. Chloramine has become a popular disinfectant in the US, and it has been found to produce N-nitrosodimethylamine (NDMA), which is a possible human carcinogen, as well as highly genotoxic iodinated DBPs, such as iodoacetic acid, when iodide is present in source waters. Residual chlorine and other disinfectants may also react further within the distribution network — both by further reactions with dissolved natural organic matter and with biofilms present in the pipes.
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This was not true of the Martian soil; on Mars, the second and third nutrient injections did not produce any further release of labeled gas." The 2011 edition of the same textbook noted that "Albet Yen of the Jet Propulsion Laboratory has shown that, under extremely cold and dry conditions and in a carbon dioxide atmosphere, ultraviolet light (remember: Mars lacks an ozone layer, so the surface is bathed in ultraviolet) can cause carbon dioxide to react with soils to produce various oxidizers, including highly reactive superoxides (salts containing O2−) When mixed with small organic molecules, superoxidizers readily oxidize them to carbon dioxide, which may account for the LR result. Superoxide chemistry can also account for the puzzling results seen when more nutrients were added to the soil in the LR experiment; because life multiplies, the amount of gas should have increased when a second or third batch of nutrients was added, but if the effect was due to a chemical being consumed in the first reaction, no new gas would be expected. Lastly, many superoxides are relatively unstable and are destroyed at elevated temperatures, also accounting for the "sterilization" seen in the LR experiment.
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The tyrosyl radical can then oxidize the 13-pro(S) hydrogen of arachidonic acid to initiate the COX cycle. Both the peroxidase and PTGS activities are inactivated during catalysis by mechanism-based, first-order processes, which means that PGHS-2 peroxidase or PTGS activities fall to zero within 1–2 minutes, even in the presence of sufficient substrates. The conversion of arachidonic acid to PGG2 can be shown as a series of radical reactions analogous to polyunsaturated fatty acid autoxidation. The 13-pro(S) -hydrogen is abstracted and dioxygen traps the pentadienyl radical at carbon 11. The 11-peroxyl radical cyclizes at carbon 9 and the carbon-centered radical generated at C-8 cyclizes at carbon 12, generating the endoperoxide. The allylic radical generated is trapped by dioxygen at carbon 15 to form the 15-(S) -peroxyl radical; this radical is then reduced to PGG2 . This is supported by the following evidence: 1) a significant kinetic isotope effect is observed for the abstraction of the 13-pro (S )-hydrogen; 2) carbon-centered radicals are trapped during catalysis; 3) small amounts of oxidation products are formed due to the oxygen trapping of an allylic radical intermediate at positions 13 and 15.
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