Yes, both Mr. Spector and Ms. Hall are dynamic, intelligent and emotionally labile.
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When we skimp on sleep, we're more anxious, emotionally labile, and negative memories tend to be more distressing, Winter says.
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This cat — a vainglorious, labile, impulsively abusive bigot, in whom Bajram's judgment and Bekim's own worst fears combine — captivates Bekim.
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He's reactive rather than active, a labile, intensely emotional man who is shredded by his own inability to discern what's real.
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But cancers are both heterogeneous and labile; elsewhere in a tumour, and later in a tumour's progression, things may look different.
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"The idea that a memory trace becomes labile when it's reactivated doesn't fit too well with the idea of consolidation," Sara said.
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"One thing about Shakespeare's plays that makes them so alive is that they are extremely labile," said Stephen Greenblatt, a Shakespeare scholar.
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Arias, an exciting and emotionally labile actor, makes Anna a jittery creature, like a woman in the constant throes of a low-grade fever.
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Nader theorized that old memories were made "labile" whenever they were recalled, and required further protein synthesis in order to remain usable in future situations.
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The research suggested that each time a memory is recalled, it enters a "labile" period—a fragile state where it can be altered or weakened.
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"But I read to her every night," said her mother, Sari Yaffee, who hopes to instill in Evans the conviction that little girls can do most anything their labile minds can dream.
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The reason people trust you is because you keep your word, you are not emotionally labile and people sense they can trust you to be who you say you're going to be with a sense of consistency.
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"Amber pieces preserve tiny snapshots of ancient ecosystems, but they record microscopic details, three-dimensional arrangements, and labile tissues that are difficult to study in other settings," one of the study's authors, Ryan McKellar of the Royal Saskatchewan Museum in Canada, said in a news release.
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In medicine, the term "labile" means susceptible to alteration or destruction. For example, a heat-labile protein is one that can be changed or destroyed at high temperatures. The opposite of labile in this context is "stable".
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Compounds or materials that are easily transformed (often by biological activity) are termed labile. For example, labile phosphate is that fraction of soil phosphate that is readily transformed into soluble or plant-available phosphate. Labile organic matter is the soil organic matter that is easily decomposed by microorganisms.
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Includes Co2+, Ni3+. :Octahedral low-spin:1 unpaired electron, paramagnetic, substitutionally labile. Includes Co2+, Ni3+. Example: [Co(NH3)6]2+. ;d8:Octahedral high-spin: 2 unpaired electrons, paramagnetic, substitutionally labile. Includes Ni2+.
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IOM itself divides into two components: thermally labile, and refractory.
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In molecular biology, the heat-labile enterotoxin family includes Escherichia coli heat-labile enterotoxin (Elt or LT) and cholera toxin (Ctx) secreted by Vibrio cholerae. lt is so named because it is inactivated at high temperatures.
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Two chloride anions are labile, whereas the coordinated chloride ligand is not.
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Enterotoxins produced by ETEC include heat-labile enterotoxin (LT) and heat- stable enterotoxin (ST).
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Labile hypertension occurs when there are unexpected changes in blood pressure. The term can be used to describe when people have blood pressure measurements that abruptly fluctuates from being abnormally high, approximately 130/80mm Hg or over and returns to its normal range. Patients who have labile hypertension may have higher cardiac output and lower total peripheral resistance than others. Behavioural and lifestyle factors are the two main factors that causes labile hypertension to occur.
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Fmoc/tBu SPPS uses base-labile Fmoc N-terminal protection, with side chain protection and a resin linkage that are acid-labile (final acidic cleavage is carried out via TFA treatment). Both approaches, including the advantages and disadvantages of each, are outlined in more detail below.
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It is somewhat less thermally labile compared to (Me2S)AuCl, but is still sensitive to temperature and light.
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Wild-type p53 is a labile protein, comprising folded and unstructured regions that function in a synergistic manner.
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Determination of apparent quantum yield spectra for the formation of biologically labile photoproducts. Limnol. Oceanogr. 47, 343–352.
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Sometimes, the episodes may switch between emotional states, resulting in the patient crying uncontrollably before dissolving into fits of laughter. The pseudobulbar affect, also referred to as emotional lability, should not be confused with labile mood or labile emotions that stem from emotional instability – affective dysregulation – commonly seen in personality disorders.
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The prevalence of labile hypertension in USA is estimated to have more than 40 million adults which can develop the risks of hemorrhagic stroke. Labile hypertension is most common in Charlottesville, Virginia with up to 11% of the population. Average age who have labile hypertension is 64±13 years. It was found that ageing was one of the characteristics that highly associates with fluctuations of blood pressure such that during day or night time, the systolic and diastolic pressure alternates and shows abnormal diurnal pattern.
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Iron(III) acetylacetonate, Fe(acac)3, is a red high- spin complex that is highly soluble in organic solvents. It is a configurationally labile, high-spin complex with five unpaired electrons. It is occasionally used as a catalyst precursor. Although configurationally labile, Fe(acac)3 has been partially resolved into its Δ and Λ isomers.
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Example: [Ni(NH3)6]2+. :Tetrahedral high-spin: 2 unpaired electrons, paramagnetic, substitutionally labile. Includes Ni2+. Example: [Ni(Cl)4]2-.
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Defects in this gene are a cause of acid-labile subunit deficiency, which manifests itself in a delayed and slow puberty.
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It can be clearly seen that RTI-336 has fewer metabolically labile sites than cocaine, and therefore has a longer duration span.
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It is noncytopathogenic -it does not kill its host cells. It is a single stranded RNA virus that is labile in the environment.
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He collaborated with Bill Jenkins and Gregg Recanzone to demonstrate sensory maps are labile into adulthood in animals performing operant sensory tasks.J. Neurophysiol.
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This structure is similar in shape, mechanism, and sequence to the heat- labile enterotoxin secreted by some strains of the Escherichia coli bacterium.
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In cellular biology, labile cells are cells that multiply constantly throughout life.Encyclopædia Britannica Online: labile cell The cells are alive for only a short period of time. Due to this, they can end up reproducing new stem cells and replace functional cells. Especially if the cells become injured through a process called necrosis, or even if the cells go through apoptosis.
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In contrast, the larger halocin proteins are heat-labile and typically obligately halophilic as they lose their activity (or activity is reduced) when desalted.
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In addition to these chemically induced oxidation reactions, sunlight can photolyze some diesel-related organics such as carbonyls that contain photo-labile functional groups.
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Epsilon-toxin is an oxygen-labile hemolysin similar to the θ-toxin of C. perfringens and the δ-toxins of C. septicum, and C. novyi.
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In species with labile sex expression this change occurs only once, where as a plant expressing diphasic sex tendencies can switch from season to season.
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Insulin-like growth factor binding protein, acid labile subunit, also known as IGFALS, is a protein which in humans is encoded by the IGFALS gene.
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Labile cells are one type of the cells that are involved in the division of cells. The other two types that are involved include stable cells and permanent cells. Each of these type of cells respond to injuries of the cells they occupy differently. Hepatocytes of the liver are thought to be a form of a labile cell because they can regenerate after they become injured.
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The synthesis of Pd-NHC complexes follows the methods used for the synthesis of transition metal NHC complexes. The synthesis of Pd-NHC complexes can also be achieved through substitution of a labile ligand L in a Pd-L complex. Labile ligands typically include cyclooctadiene, dibenzylideneacetone, bridging halides or phosphines. This process can be used in conjunction with the in-situ generation of free carbenes.
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Also CN-PAGE is milder than BN-PAGE so it can retain labile supramolecular assemblies of membrane protein complexes that are dissociated under the conditions of BN-PAGE.
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Arcadelt alternates homophonic and polyphonic textures, "in a state of delicate, labile equilibrium."Blume, Friedrich. Renaissance and Baroque Music. New York: W. W. Norton & Company, Inc., 1967. p. 67.
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The use of chemical agents as a means to alter traumatic memories has a basis in Molecular Consolidation Theory. Molecular Consolidation theory says that memory is created and solidified (or consolidated) by specific chemical reactions in the brain. Initially, memories exist in a plastic, labile state before they are more solidly encoded. It has been argued that memory consolidation occurs more than once- each time a memory is recalled, it returns to a labile state.
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Mixing it up in the ocean carbon cycle and the removal of refractory dissolved organic carbon. Sci. Rep. 8:2542. doi: 10.1038/s41598-018-20857-5 As such, the compositional changes that occur during degradation are more complex than the simple removal of more labile components and resultant accumulation of remaining, less labile compounds. Dissolved organic matter recalcitrance (i.e., its overall reactivity toward degradation and/or utilization) is therefore an emergent property.
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These complexes exist in either the N or the O linkage isomers. It can be assumed that such monodentate complexes exist transiently for many kinetically labile metal ions (e.g. Zn2+).
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The migration of two labile chloride ligands from harder Cu(II) to softer Hg(II) drives the formation of the crystal.Draper, N.D. Chemistry of Materials 2003, 15(8), 1612–1616.
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The MAO serves two roles: (i) alkylation of the metallocene halide and (ii) abstraction of an anionic ligand (chloride or methyl) to give an electrophilic catalyst with a labile coordination site.
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Mood stabilizers (used primarily to treat Bipolar disorder) such as lithium or lamotrigine may be of some use to help depressed or labile periods, as well as rapid changes in mood.
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Extrinsic factors such as physical activities, insomnia and intake of sodium are likely to increase the occurrence of labile hypertension. Reduced arterial compliance and baroreflex failure may contribute to trigger a response as well. Diagnosis is typically by 24 hours ambulatory blood pressure monitoring to which measurements can be taken at home without having to visit to the physician’s office. Labile hypertension can be a primary risk factor that may contribute to stroke or cardiovascular disease (CVD).
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Labile hypertension can be initially treated through behavioural modifications. Behavioural factors such as the mental activity of an individual or emotional status should be managed. Anxiety is one of the common forms of mental illness, there are increasing risks that can affect physical health problems. Therefore, to reduce stress and anxiety, reduction to smoking and alcohol, decreasing intake of salt or having regular aerobic activity are some examples of therapy that can help manage cases of labile hypertension.
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Vinyl alcohol, also called ethenol (IUPAC name), is the simplest enol. With the formula 2CHH, it is a labile compound that converts to acetaldehyde. It is not a precursor to polyvinyl alcohol.
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22, 417–420. doi: 10.1029/94GL03344Moran, M. A., and Zepp, R. G. (1997). Role of photoreactions in the formation of biologically labile compounds from dissolved organic matter. Limnol. Oceanogr. 42, 1307–1316.
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Includes Cr2+, Mn3+. :Octahedral low-spin: 2 unpaired electrons, paramagnetic, substitutionally inert. Includes Cr2+, Mn3+. ;d5: :Octahedral high-spin: 5 unpaired electrons, paramagnetic, substitutionally labile. Includes Fe3+, Mn2+. Example: [Mn(H2O)6]2+.
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Includes Fe2+, Co3+. Example: [CoF6]3−. :Octahedral low-spin: no unpaired electrons, diamagnetic, substitutionally inert. Includes Fe2+, Ni4+. Example: [Co(NH3)6]3+. ;d7: :Octahedral high-spin: 3 unpaired electrons, paramagnetic, substitutionally labile.
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It can be buffered with pyridine or sodium bicarbonate in order to protect acid-labile compounds. The acceleration of the Dess–Martin oxidation reaction using water has been shown by Meyer and Schreiber.
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The rate of the Grubbs catalyst can be altered by replacing the phosphine ligand with more labile pyridine ligands. By using 3-bromopyridine the initiation rate is increased more than a millionfold. Both pyridine and 3-bromopyridine are commonly used, with the bromo- version 4.8 times more labile resulting in even faster rates. The catalyst is traditionally isolated as a two pyridine complex, however one pyridine is lost upon dissolving and reversibly inhibits the ruthenium center throughout any chemical reaction.
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If the patient is taking warfarin, then knowledge of INR control is needed to assess the 'labile INR' criterion in HAS-BLED; otherwise for a non-warfarin patient, this criterion scores zero. A high HAS-BLED score is not a reason to withhold anticoagulation. Also, when compared to HAS-BLED, other bleeding risk scores that did not consider 'labile INR' would significantly underperform in predicting bleeding on warfarin, and would often inappropriately categorise many patients who sustained bleeds as 'low risk'.
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Benzonitrile forms coordination complexes with transition metals that are both soluble in organic solvents and conveniently labile. One example is . The benzonitrile ligands are readily displaced by stronger ligands, making benzonitrile complexes useful synthetic intermediates.
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Because of its mild heat treatment, pasteurization increases the shelf-life by a few days or weeks. However, this mild heat also means there are only minor changes to heat-labile vitamins in the foods.
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RAPTA compounds are ruthenium–arene complexes bearing the 1,3,5-triaza-7-phosphatricyclo-[3.3.1.1]decane ligand. The complex has a piano stool geometry. The PTA ligand confers water solubility, and the two chloride ligands are labile.
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Most metals dissolved in the aqueous environment are present as any of several ionic, complex-ion, and organically bound states. For most toxic metals, bioavailability is greatest for labile metals in their free ionic state. Recognizing the potential usefulness of a passive sampling device that could be used to measure trace amounts of bioavailable toxic metals, researchers at the United States Geological Survey (USGS) and University of Missouri began development on a counterpart to SPMDs that could be used to sample for labile metals.
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A chiral substituted crown ether catalyst developed by Jean-Marie Lehn for ester cleavage. The crown ether binds the aminium ion so that the labile group (in red) is positioned next to the reactive group (in blue). A supramolecular host could bind to a guest molecule in such a way that the guest's labile group is positioned close to the reactive group of the host. The proximity of the two groups enhances the probability that the reaction could occur and thus the reaction rate is increased.
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A major application of FD is to determine the molecular mass of a large variety of thermally labile and stable nonvolatile, nonpolar, and polar organic and organometallic compounds, and of molecules from biochemical and environmental sources.
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With addition of D2O, sometimes referred to as a D2O shake, labile hydrogens exchange away and are substituted by deuterium (2H) atoms. These positions in the molecule then do not appear in the 1H-NMR spectrum.
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Acid-labile substrates are less likely to undergo rearrangement and elimination since DAST is less prone to contamination with acids. Reaction temperatures are milder as well – alcohols typically react at −78 °C and ketones around 0 °C.
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The first Fischer carbyne was isolated in 1973. Two years later in 1975, the first Schrock carbyne was reported. Metal carbyne complexes also exhibit a large trans effect, where the ligand opposite the carbyne is typically labile.
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As the majority of the structural remnants of the necrotic tissue remains, labile cells adjacent to the affected tissue will replicate and replace the cells which have been killed during the event. Labile cells are constantly undergoing mitosis and can therefore help reform the tissue, whereas nearby stable and permanent cells (e.g. neurons and cardiomyocytes) do not undergo mitosis and will not replace the tissue affected. Fibroblasts will also migrate to the affected area depositing fibrous tissue producing fibrosis or scarring in areas where viable cells do not replicate and replace tissue.
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Anti-streptolysin O (ASO or ASLO) is the antibody made against streptolysin O, an immunogenic, oxygen-labile streptococcal hemolytic exotoxin produced by most strains of group A and many strains of groups C and G Streptococcus bacteria. The "O" in the name stands for oxygen-labile; the other related toxin being oxygen-stable streptolysin-S. The main function of streptolysin O is to cause hemolysis (the breaking open of red blood cells) — in particular, beta-hemolysis. Increased levels of ASO titre in the blood could cause damage to the heart and joints.
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Labile molecules are present at low concentrations outside of cells (in the picomolar range) and have half-lives of only minutes when free in the ocean. They are consumed by microbes within hours or days of production and reside in the surface oceans, where they contribute a majority of the labile carbon flux. Semilabile molecules, much more difficult to consume, are able to reach depths of hundreds of meters below the surface before being metabolized. Refractory DOM largely comprises highly conjugated molecules like Polycyclic aromatic hydrocarbons or lignin.
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RBC transfusion is necessary for many patients. However, to date the supply of RBCs remains labile. In addition, transfusion risks infectious disease transmission. A large supply of safe RBCs generated in vitro would help to address this issue.
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Role of photoreactions in the formation of biologically labile compounds from dissolved organic matter. Limnol. Oceanogr. 42, 1307–1316. doi: 10.4319/lo.1997.42.6.1307Stubbins, A., Uher, G., Law, C. S., Mopper, K., Robinson, C., and Upstill-Goddard, R. C. (2006).
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Storage is in the form of non-labile soil organic carbon (SOC), which is part of the soil organic matter (SOM) pools. SOM pools are also increased by leaves’ senescence, and by animals returning undigested fibre to the soil.
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The antibiotic is highly soluble in water and is acid-labile. A typical lab working concentration is 50 µg per ml. It is a semi-synthetic analogue of the naturally occurring benzyl- penicillin. Carbenicillin at high doses can cause bleeding.
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A divorce followed. Back in Austria, however, Bode married the 22-year-old Inge Pelz on the Midsummer Day in 1957. The success in Austria continued, but was no good medicine for the labile Bode. He continued in more wild style.
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The {Cu2} units in the inner sphere adapt several different orientations. The labile complexes in the inner sphere allow binding of large target guests on the nanometer scale. Building a complex of this size that is still soluble is a challenge.
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Awkwardness, stuttering, shyness, and confusion predominate at the behavioral level. Sufferers complain of abandonment, despair, and diabolically humiliating disappointment. A sense of paralyzing ambiguity predominates, punctuated by pining. Intermittent or nonreciprocal responses lead to labile vacillation between despair and ecstacy.
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This approach circumvents the comparatively time-consuming isolation of the product peptide from solution after each reaction step, which would be required when using conventional solution-phase synthesis. Each amino acid to be coupled to the peptide chain N-terminus must be protected on its N-terminus and side chain using appropriate protecting groups such as Boc (acid-labile) or Fmoc (base-labile), depending on the side chain and the protection strategy used (see below). The general SPPS procedure is one of repeated cycles of alternate N-terminal deprotection and coupling reactions. The resin can be washed between each steps.
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Domain A1 (approximately 22kDa in cholera toxin or heat labile enterotoxins) is the part of the toxin responsible for its toxic effects. Domain A2 (approximately 5kDa in cholera toxin or heat labile enterotoxin) provides a non-covalent linkage to the B subunit through the B subunit's central pore. The A1 chain for cholera toxin catalyzes the transfer of ADP-ribose from Nicotinamide adenine dinucleotide(NAD) to arginine or other guanidine compounds by utilizing ADP- ribosylation factors (ARFs). In the absence of arginine or simple guanidino compounds, the toxin mediated NAD+ nucleosidase (NADase) activity proceeds using water as a nucleophile.
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Chloro(tetrahydrothiophene)gold(I), abbreviated (tht)AuCl, is a coordination complex of gold. Like the dimethyl sulfide analog, this compound is used as a convenient entry point to gold chemistry. The tetrahydrothiophene ligand is labile and is readily substituted with other stronger ligands.
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25I-NBOH is a labile molecule which fragments into 2C-I when analyzed by routine gas chromatography (GC) methods. A specific method for reliable identification of 25I-NBOH using GC/MS has been reported, allowing forensic forces worldwide to correctly identify this compound.
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Sulfenamides, e.g. cyclohexylthiophthalimide, are used extensively in the vulcanization of rubber. The sulfenamides are used to accelerate the process via the transient formation of labile S-N bonds. The substituents on the sulfenamides determine the point at which they will become active.
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Solid cyanamide is produced by careful evaporation of the solvent and subsequent addition of a hydrolysis-labile ester of formic acid. The ester absorbs traces of moisture (suppression of urea formation), neutralizes alkalinity (ammonia) and continually releases small amounts of formic acid.
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The azide and the acetylide are not coordinated to the same Cu atom in this case. The ligands employed are labile and are weakly coordinating. The azide displaces one ligand to generate a copper-azide-acetylide complex. At this point cyclization takes place.
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For workups involving acid-labile products, mildly basic solutions or pH 7–8 buffers may be used. Samarium salts are usually insoluble in these conditions, but do form a suspension in the aqueous phase from which the desired organic product can be extracted.
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A closely related compound is bis(acetonitrile)palladium dichloride. The complex is prepared by dissolving PdCl2 in warm benzonitrile. The PhCN ligands are labile, and the complex reverts to PdCl2 in noncoordinating solvents. According to X-ray crystallography, the two PhCN ligands are mutually trans.
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Reduction of Mo(CO)6 gives [Mo(CO)5]2− which is formally Mo(-II). CO-free Mo(0) compounds tend to be more reducing and kinetically labile than the carbonyl complexes. Examples include bis(benzene)molybdenum (Mo(C6H6)2) and tris(butadiene)molybdenum.
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In analytical chemistry, triphenylphosphine is used for the analysis of certain kinds of sulfur compounds. Elemental sulfur (S8), as occurs in some oils, and labile organosulfur compounds, such as organic trisulfides, react with triphenylphosphine to give Ph3PS, which can be detected by gas chromatography.
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Enteroviruses are stable under acidic conditions and thus they are able to survive exposure to gastric acid. In contrast, rhinoviruses are acid-labile (inactivated or destroyed by low pH conditions) and that is the reason why rhinovirus infections are restricted to the nose and throat.
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Spufford had struggled with physical health issues for all her adult life. While in her 30s, early onset osteoporosis was diagnosed. She also survived cancer and high and labile blood pressure. She was diagnosed with vascular dementia and Lewy bodies dementia in autumn 2011.
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Some of the carbonyl ligands are highly labile. The compound is highly reactive towards alkynes, and is sometimes used as an alkyne protecting group. As the cobalt-alkyne complex, it plays a role in promoting both the Nicholas reaction and the Pauson–Khand reaction.
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For first row transition metal complexes such as Ni2+ and Cu+ also form five-coordinate 18-electron species which vary from square pyramidal to trigonal bipyramidal. :Octahedral high spin: 2 unpaired electrons, paramagnetic, substitutionally labile. :Square planar low spin: no unpaired electrons, diamagnetic, substitutionally inert.
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They allow the incorporation of thermally labile and solvent-sensitive active ingredients at room temperature without the use of organic solvents. Such drug implants are particularly suitable for applications on the eye, where no sudden release occurs by diffusion (initial burst release) but the release follows the continuous polymer degradation. Also for Polyorthoesters type III the degradation occurs at the surface by cleavage of the hydrolytically labile bonds in the polymer backbone. POE III-Degradation Depending on the initial bond cleavage on the quaternary carbon atom 1-, 2-, or 6-acetoxy-hexanetriol is formed, which is further degraded to acetic acid and 1,2,6-hexanetriol.
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Also important to the pharmacokinetics of a drug is its interactions with food during adsorption because this affects the dosage required. Deramciclane is an acid-labile compound. Acid-labile compounds are more easily broken down in acidic environments, so the decrease in stomach pH as a result of the presence of food could have adverse effects on the bioavailability of deramciclane. Clinical studies investigating the effects of food or lack thereof on deramciclane adsorption show that there is a statistically significant, but not clinically relevant, increase in bioavailability of deramciclane when administered with food because the point of critical instability of deramciclane is relatively low at a pH of 2.
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It was remarked that labile sleep-wake cycles (labile meaning more easily roused) with some distinct changes in sleep, such as dream-like states, hypnogogic, hypnopompic hallucinations, night-terrors and other disorders related to sleep could possibly be causative or improve symptoms to a degree. Derealization can also be a symptom of severe sleep disorders and mental disorders like depersonalization disorder, borderline personality disorder, bipolar disorder, schizophrenia, dissociative identity disorder, and other mental conditions. Cannabis, psychedelics, dissociatives, antidepressants, caffeine, nitrous oxide, albuterol, and nicotine can all produce feelings mimicking feelings of derealization, particularly when taken in excess. It can also result from alcohol withdrawal or benzodiazepine withdrawal.
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Full article: Biological pump Particulate organic carbon, created through biological production, can be exported from the upper ocean in a flux commonly termed the biological pump, or respired (equation 6) back into inorganic carbon. In the former, dissolved inorganic carbon is biologically converted into organic matter by photosynthesis (equation 5) and other forms of autotrophy that then sinks and is, in part or whole, digested by heterotrophs. Particulate organic carbon can be classified, based on how easily organisms can break them down for food, as labile, semilabile, or refractory. Photosynthesis by phytoplankton is the primary source for labile and semilabile molecules, and is the indirect source for most refractory molecules.
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On the other hand, new sediments are continuously being formed. Thus, new waterfalls are being formed while others run dry. Nature itself is continuously adapting to these new conditions. As a whole, the complex of lakes represents a very sensitive and labile (liable to change) ecosystem.
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Thus, the carbon is bonded to five boron atoms and one hydrogen atom. The cation [(PhPAu)C] contains an octahedral carbon bound to six phosphine-gold fragments. This phenomenon has been attributed to the aurophilicity of the gold ligands, which provide additional stabilization of an otherwise labile species.
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Unsubstituted imidazolidines are often labile. The rings are susceptible to hydrolysis back to the diamine and the aldehyde. Formally, removal of the two hydrogens at carbon 2 (between the two nitrogens) would yield the carbene dihydroimidazol-2-ylidene. Derivatives of the latter comprise an important class of persistent carbenes.
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"LSD," writes the chemist Alexander Shulgin, "is an unusually fragile molecule ... As a salt, in water, cold, and free from air and light exposure, it is stable indefinitely." LSD has two labile protons at the tertiary stereogenic C5 and C8 positions, rendering these centres prone to epimerisation. The C8 proton is more labile due to the electron-withdrawing carboxamide attachment, but removal of the chiral proton at the C5 position (which was once also an alpha proton of the parent molecule tryptophan) is assisted by the inductively withdrawing nitrogen and pi electron delocalisation with the indole ring. LSD also has enamine-type reactivity because of the electron-donating effects of the indole ring.
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He also introduced the concepts of environmentally stable or labile human behaviour allowing for the revolutionary combination of the idea of a species-specific genetic bias to become attached and the concept of individual differences in attachment security as environmentally labile strategies for adaptation to a specific childrearing niche. Alternatively, Bowlby's thinking about the nature and function of the caregiver-child relationship influenced ethological research, and inspired students of animal behaviour such as Tinbergen, Hinde, and Harry Harlow. One of Harlow's students, Stephen Suomi, wrote about the contributions Bowlby's made to ethology, including that Barlow brought attachment research into animal research specifically with rhesus monkeys and various other species of monkeys and apes.Suomi, S. J. (1995).
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Those receptors, which we now call "antibodies", were called by Ehrlich "amboceptors" to emphasise their bifunctional binding capacity: They recognise and bind to a specific antigen, but they also recognise and bind to the heat-labile antimicrobial component of fresh serum. Ehrlich, therefore, named this heat-labile component "complement", because it is something in the blood that "complements" the cells of the immune system. Ehrlich believed that each antigen-specific amboceptor has its own specific complement, whereas Bordet believed that there is only one type of complement. In the early 20th century, this controversy was resolved when it became understood that complement can act in combination with specific antibodies, or on its own in a non-specific way.
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Jack-in-the-pulpit is known for diphasic sex expression, with many individuals changing from male to female with sufficient plant growth. Diphasic sex expression (also known as labile sex expression or sex change), is defined as the alteration of the primary sex during the lifetime of an individual found within dioecious and subdioecious species of plants. This change in sex expression is a response to environmental cues such as sun exposure and rainfall or drought levels. Labile sex expression is a type of diphasic sex expression that is found among many perennial plant species, and is defined as the switch from male to female once the plant has reached a certain size.
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Homoleptic cyanometallates refers to complexes where the only ligand is cyanide. For the first row transition metals, well known homoleptic cyanometallates are the hexacyanides. Hexacyanometalates are known for Ti(III), V(III), Cr(III), Mn(III), Fe(II), Fe(III), and Co(III). Other more labile derivatives are known as well.
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Ornithine decarboxylase (ODC), is a labile protein that is the first rate-limiting enzyme in polyamine biosynthesis. Its degradation is regulated by antizyme that is induced by polyamine production. NQO1 has been shown to stabilize the degradation of ODC by binding to it and protecting it from 20S proteasomal degradation.
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However tellurium hydride and polonium hydride are both volatile and highly labile. Also, oxygen can bond to hydrogen in a 1:1 ratio as in hydrogen peroxide, but this compound is unstable. Chalcogen compounds form a number of interchalcogens. For instance, sulfur forms the toxic sulfur dioxide and sulfur trioxide.
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A lysis buffer is a buffer solution used for the purpose of breaking open cells for use in molecular biology experiments that analyze the labile macromolecules of the cells (e.g. western blot for protein, or for DNA extraction). Most lysis buffers contain buffering salts (e.g. Tris-HCl) and ionic salts (e.g.
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Chlorobis(ethylene)rhodium dimer is an organorhodium compound with the formula Rh2Cl2(C2H4)4. It is a red-orange solid that is soluble in nonpolar organic solvents. The molecule consists of two bridging chloride ligands and four ethylene ligands. The ethylene ligands are labile and readily displaced even by other alkenes.
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A vaccine bath is an apparatus used in vaccine production. As vaccines are very heat labile but inevitably need to be heated to some extent, these devices are used. These are basically water baths, with a temperature set very low. A long time is taken to sterilize vaccines by this method.
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Cholera toxin mechanism Cholera toxin (also known as choleragen and sometimes abbreviated to CTX, Ctx or CT) is AB5 multimeric protein complex secreted by the bacterium Vibrio cholerae. CTX is responsible for the massive, watery diarrhea characteristic of cholera infection. It is a member of the Heat- labile enterotoxin family.
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Acting as stem cells for these cell types. In labile cells, it is not a speed-up in the segments of the cell cycle (i.e. G1 phase, S phase, G2 phase and M phase), but rather a short or absent G0 phase that is responsible for the cells' constant division.
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During this phase, memory problems worsen, and the person may fail to recognise close relatives. Long-term memory, which was previously intact, becomes impaired. Behavioural and neuropsychiatric changes become more prevalent. Common manifestations are wandering, irritability and labile affect, leading to crying, outbursts of unpremeditated aggression, or resistance to caregiving.
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Rhodium(0) complexes are binary carbonyls, the principal examples being tetrarhodium dodecacarbonyl, Rh4(CO)10, and hexadecacarbonylhexarhodium, Rh6(CO)16. These compounds are obtained by reductive carbonylation of rhodium(III) salts or Rh2Cl2(CO)4. In contrast to the stability of the homologous Co2(CO)8, Rh2(CO)8 is very labile.
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Transition metal nitrile complexes are usually employed because the nitrile ligand is labile and relatively chemically inert. Cationic nitrile complexes are however susceptible to nucleophilic attack at carbon. Consequently some nitrile complexes catalyze the hydrolysis of nitriles to give the amides. Fe- and Co- nitrile complexes are intermediates in nitrile hydratase enzymes.
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This highly labile feature can fluctuate depending on changes in shape and weight, the degree of control over eating and mood. In contrast, a necessary diagnostic feature for anorexia nervosa and bulimia nervosa is having overvalued ideas about shape and weight are relatively stable and closely related to the patients’ low self-esteem.
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Copper(I) forms only labile complexes with ammonia, including the trigonal planar [Cu(NH3)3]+. Silver gives the diammine complex [Ag(NH3)2]+ with linear coordination geometry. It is this complex that forms when otherwise rather insoluble silver chloride dissolves in aqueous ammonia. The same complex is the active ingredient in Tollen's reagent.
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The ligands co-ordinating the metal ion can vary with histidine, glutamate, aspartate, lysine, and arginine. The fourth coordination position is taken up by a labile water molecule. Treatment with chelating agents such as EDTA leads to complete inactivation. EDTA is a metal chelator that removes zinc, which is essential for activity.
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Labile cells refer to cells that constantly divide by entering and remaining in the cell cycle. These are contrasted with "stable cells" and "permanent cells". An important example of this is in the epithelium of the cornea, where cells divide at the basal level and move upwards, and the topmost cells die and fall off.
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Against the one-way relation of reference Gombrich argues for a weaker or labile relation, inherited from substitution.Gombrich, E. H. (1960): pp 80-98, (1982): pp 278–297. Pictures are thus both more primitive and powerful than stricter reference. But whether a picture can deceive a little while it represents as much seems gravely compromised.
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Factor V (pronounced factor five) is a protein of the coagulation system, rarely referred to as proaccelerin or labile factor. In contrast to most other coagulation factors, it is not enzymatically active but functions as a cofactor. Deficiency leads to predisposition for hemorrhage, while some mutations (most notably factor V Leiden) predispose for thrombosis.
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Chemically, borole is reactive and unstable in ambient conditions. The pentaphenylborole analog is a highly reactive green solid; it readily undergoes oxidation, partial protolysis, and Diels−Alder reaction with dienophiles. Borole, even in perarylated form, is still very labile. Due to its reactive nature, the structural parameters and thermochemical data of borole are not known.
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APCI is suited for thermal stable samples with low to medium (less than 1500Da) molecular weight, and medium to high polarity. The application area of APCI is the analysis of drugs, nonpolar lipids, natural compounds, pesticides and various organic compounds, but limited to the analysis of biopolymers, organometallics, ionic compounds and other labile analytes.
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Ginger compounds have been shown to be active against enterotoxigenic Escherichia coli heat-labile enterotoxin- induced diarrhea. This type of diarrhea is the leading cause of infant death in developing countries. Zingerone is likely the active constituent responsible for the antidiarrheal efficacy of ginger. Zingerone is recognized as being a particularly efficient free radical scavenger.
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It is envisaged that RAPTA derivatives have the “piano stool” structure like others organometallic half-sandwich compound; however, their crystal structures have not been determined. The PTA ligand was designed to make the complexes more soluble in water, and the two labile chlorido ligands can exchange to aquo ligand in the presence of water.
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Dienes are widely used chelating ligands in organometallic chemistry. In some cases they serve as placeholder ligands, being removed during a catalytic cycle. For example, the cyclooctadiene ("cod") ligands in bis(cyclooctadiene)nickel(0) are labile. In some cases, dienes are spectator ligands, remaining coordinated throughout a catalytic cycle and influencing the product distributions.
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After protection of the hydroxyl group with an acyl or silyl group, cyanohydrins can function essentially as masked acyl anions. Because ester protecting groups are base labile, mild bases must be employed with ester- protected cyanohydrins. α-(Dialkylamino)nitriles can also be used in this context. Examples of arylation and acylation reactions are shown below.
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The test results showed 11 negative responses, 14 doubtful/probably irritant responses and only 1 mild positive response. The authors concluded that the original subject "belongs to a group of patients who have sensitive, labile skin that easily contract new allergies." Thus, the 61-year-old woman had apparently developed a sensitization towards SSL.
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Prolonged exposure to sunlight initiates [2+2] cycloadditions, converting it to a mixture of a dimeric and a trimeric cyclobutane cycloadduct. Dibenzylideneacetone is a component of the catalyst tris(dibenzylideneacetone)dipalladium(0). It is a labile ligand that is easily displaced by triphenylphosphine, hence it serves a useful entry point into palladium(0) chemistry.
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Surface eroding polymers do not allow water to penetrate into the material. They erode layer by layer, like a lollipop. The hydrophobic backbone with hydrolytically labile anhydride linkages allows hydrolytic degradation to be controlled by manipulating the polymer composition. This manipulation can occur by adding a hydrophilic group to the polyanhydride to make a copolymer.
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The icosahedral shell encapsulating enzymes and labile intermediates are built of different types of proteins with BMC domains. In 1904, Ernst Haeckel described a number of species of Radiolaria, including Circogonia icosahedra, whose skeleton is shaped like a regular icosahedron. A copy of Haeckel's illustration for this radiolarian appears in the article on regular polyhedra.
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Mycoplasma species are labile organisms which are easily destroyed by heat, dehydration, sunlight, and common disinfectants, so they do not survive for a long time outside the body of the animal. As of now, and with many Mycoplasma diseases, no protective immune responses have been achieved with the use of vaccines, though antibodies can be obtained.
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Structure of the adduct of InH3 and tricyclohexylphosphine. Several compounds with In-H bonds have been reported. Examples of complexes with two hydride ligands replaced by other ligands are K3[K(Me2SiO)7][HIn(Me3CCH2)3]4 and HIn(2-Me2NCH2-C6H4)2. Although InH3 is labile, adducts are known with the stoichiometry InH3Ln (n = 1 or 2).
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The technique was first reported by Beckey in 1969.Beckey H.D. Field ionization mass spectrometry. Research/Development, 1969, 20(11), 26 It is also the first ionization method to ionize nonvolatile and thermally labile compounds. One major difference of FD with other ionization methods is that it does not need a primary beam to bombard a sample.
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This is then enclosed in an envelope to create a smooth surface. The envelope consists of two proteins, VP2 and VP3. VP2 has a molecular weight of 18,000, and VP3 is a heterogeneous glycoprotein of molecular weight 15,000. The envelope is extremely labile and tends to slough off; this characteristic is indicated by its extreme sensitivity to detergent treatment.
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Gender and sexuality within this world is fluid and expansive, with the principal categories of gender and sexuality listed to include feminine, masculine, androgynous, ambisexual, bisexual, neuter, eunuch, nonsexual, undifferentiated, gay, lesbian, queer, invert, homosexual, polymorphous, poly, labile, berdache, hijra, and two-spirit. Many people exhibit intersex or "gynandromorphous" sex characteristics, including both penises and vaginas.
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However, research has shown that in the specific case of carotenoids a greater proportion is absorbed from cooked vegetables than from raw vegetables. German research in 2003 showed significant benefits in reducing breast cancer risk when large amounts of raw vegetable matter are included in the diet. The authors attribute some of this effect to heat-labile phytonutrients.Nutr Cancer.
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Voids formed in the fossils as the carbon films were heated and released volatile components. Different types of kerogen – reflecting different initial conditions – mature (i.e. volatilize) at different temperatures and pressures. The first kerogens to mature are those that replace labile tissue such as guts and organs; cuticular regions produce more robust kerogens that mature later.
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An enterotoxin is a protein exotoxin released by a microorganism that targets the intestines. Enterotoxins are chromosomally encoded or plasmid encodedCarlton Gyles, Magdalene So, Stanley Falkow, Journal of Infectious Diseases (1974) 130 (1): 40-49. exotoxins that are produced and secreted from several bacterial organisms. They are heat labile (>60⁰), and are of low molecular weight and water-soluble.
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A number of differences are apparent between pyridine and bipyridine complexes. Many [M(bipy)3]z complexes are known, whereas analogous [M(py)6]z complexes are rare and apparently labile. Bipyridine is a redox-noninnocent ligand, as illustrated by the existence of complexes such as [Cr(bipy)3]0. The pyridine analogues of such complexes are unknown.
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Flax roots associate with arbuscular mycorrhizal fungi.In terrestrial environments, fine roots absorb water and nutrients from soil, and return such resources to the soil upon death and decomposition. Fine roots also release exudates, including labile carbon, during life processes and turnover. This directly affects soil organic carbon pools, and indirectly affects them by stimulating microbial activity.
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That two elements so different in atomic number have the same radius is a consequence of the d-block contraction. Whilst calcium is somewhat larger than magnesium, there is a steady decrease in size as atomic number increases from calcium to zinc. Zn(II) complexes are kinetically labile, i.e. the Zn-ligand bonds exchange with other ligands rapidly.
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IOMAI was acquired by Intercell in 2008 and the technology was the subject of a development license to GSK in 2009. Dr. Glenn pioneered needle free delivery to the skin and spawned general interest in skin-targeting vaccine technologies, including intradermal delivery and the use of the heat labile toxin as an adjuvant and the adjuvant patch.
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Within this class, the number of bonds formed from the carbon to each metal can be determined by the valence needs of the respective metals. The polar covalent class is similar to the metallacarbyne class, but the Metal-Carbon bond with the lower bond order is more labile and can be compared to a Lewis acid adduct.
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A putative catalytic residue in the A1 fragment (Glu112) lies close to a hydrophobic region, which packs two loops together. It is thought that this region might be important for catalysis and membrane translocation. The structural arrangement of E. coli type I and type II heat-labile enterotoxins are very similar, although they are antigenically distinct.
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Related to mesylate is the mesyl (Ms) or methanesulfonyl (CH3SO2) functional group. Methanesulfonyl chloride is often referred to as mesyl chloride. Whereas mesylates are often hydrolytically labile, mesyl groups, when attached to nitrogen, are resistant to hydrolysis.Valerie Vaillancourt, Michele M. Cudahy, Matthew M. Kreilein and Danielle L. Jacobs "Methanesulfonyl Chloride" in E-EROS Encyclopedia for Reagents in Organic Synthesis.
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Streptolysin is a streptococcal hemolytic exotoxin. Types include streptolysin O (SLO), which is oxygen-labile, and streptolysin S (SLS), which is oxygen- stable. An antibody, antistreptolysin O, can be detected in an antistreptolysin O titre. Streptolysin O is hemolytically active only in a reversibly reduced state, unlike streptolysin S, which is stable in the presence of oxygen.
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However, it is argued that reductions in lignin may compromise the structural integrity of the plant, thereby making it more susceptible to wind, snow, pathogens and disease, which could necessitate pesticide use exceeding that on traditional plantations. This has proven correct, and an alternative approach followed by the University of Columbia was developed. This approach was to introduce chemically labile linkages instead (by inserting a gene from the plant Angelica sinensis ), which allows the lignin to break down much more easy.Monolignol Ferulate Transferase Introduces Chemically Labile Linkages into the Lignin Backbone Due to this new approach, the lignin from the trees not only easily breaks apart when treated with a mild base at temperatures of 100 degrees C, but the trees also maintained their growth potential and strength.
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Further experimentation suggested that chemical defense of queens is highly labile. It was shown that queens reared on the high-cardenolide A. curassavica sequester and store levels of cardenolides similar to those found in monarchs. These butterflies were regarded as very distasteful and were largely rejected by avian predators. Furthermore, those that were eaten elicited high rates of distress behavior.
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Class III bacteriocins are large, heat-labile (>10 kDa) protein bacteriocins. This class is subdivided in two subclasses: subclass IIIa (bacteriolysins) and subclass IIIb. Subclass IIIa comprises those peptides that kill bacterial cells by cell wall degradation, thus causing cell lysis. The best studied bacteriolysin is lysostaphin, a 27 kDa peptide that hydrolyzes the cell walls of several Staphylococcus species, principally S. aureus.
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Anisomycin interferes with protein and DNA synthesis by inhibiting peptidyl transferase or the 80S ribosome system. Anisomycin is also mentioned as a potential psychiatric drug, as it may inhibit the consolidation of new context-specific long-term memories, as well as long time consolidated memories rendered labile through reactivation. Injection of anisomycin into the hippocampus has been proposed for selective removal of memories.
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Pivalonitrile is a nitrile with the semi-structural formula (CH3)3CCN, abbreviated t-BuCN. This aliphatic organic compound is a clear, colourless liquid that is used as a solvent and as a labile ligand in coordination chemistry. Pivalonitrile is isomeric with tert-butyl isocyanide but the two compounds do not exist in chemical equilibrium, unlike its silicon analog trimethylsilyl cyanide.
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Reconsolidation of a memory involves the retrieval of an already consolidated memory (explicit or implicit), into short-term or working memory. Here it is brought into a labile state where subsequent information can interfere with what is currently in memory, therefore altering the memory. This is known as retroactive interference, and is an extremely significant issue for court and eyewitness testimonies.
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Costameres are also involved in protecting the relatively weak and labile sarcolemma from the mechanical stresses of contraction and stretching. The proteins mechanically support the lipid bilayer, and also may facilitate an organized folding of the plasma membrane ("festooning") that minimizes stress on the bilayer during contraction and stretching. Finally, costameres are also involved in the orchestration of mechanically related signaling.
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The thermal reaction of Mo(CO)6 with piperidine affords Mo(CO)4(piperidine)2. The two piperidine ligands in this yellow-colored compound are labile, which allows other ligands to be introduced under mild conditions. For instance, the reaction of [Mo(CO)4(piperidine)2] with triphenyl phosphine in boiling dichloromethane (b.p. ca. 40 °C) gives cis-[Mo(CO)4(PPh3)2].
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Bromo(tetrahydrothiophene)gold(I) is a coordination complex of gold. It is related to the more commonly used chloro(tetrahydrothiophene)gold(I). Similarly, the tetrahydrothiophene ligand is labile and is readily substituted with other stronger ligands, to give linear gold bromide complexes. This compound may be prepared by reaction of tetrabromoauric acid (formed from tetrachloroauric acid and hydrobromic acid) with tetrahydrothiophene.
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In acid conditions, hydrogen selenide, H2Se, is formed. Some selenides are reactive to oxidation by air. Owing to the greater reducing power of selenide, metal selenides are more easily decomposed to the elements than are sulfides (tellurides are even more labile). Selenides of electropositive metals: such as aluminium selenide readily hydrolyse, even in moist air, evolving toxic hydrogen selenide gas.
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Strontium peroxide is produced by passing oxygen over heated strontium oxide. Upon heating in the absence of O2, it degrades to SrO and O2. It is more thermally labile than BaO2.Bauschlicher, Charles W. Jr.; Partridge, Harry; Sodupe, Mariona; Langhoff, Stephen R. "Theoretical study of the alkaline-earth metal superoxides BeO2 through SrO2" Journal of Physical Chemistry 1992, volume 96, pp. 9259-64.
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The chemical structure of most of urochromes is still unknown, since they are very labile pigments that are easily decomposed in the light. In particular uroerythrin, remains unresolved until 1975 with previous papers that describes it like a peptidic compound.Minder, W. (1970) Doctoral thesis, University of Berne, CHHansen, S. E. (1969) Acta Chenz. Scand. 23, 3461-3465Hansen, S. E. (1969) Acta Chenz. Scand.
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Mammalian influenza viruses tend to be labile, but can survive several hours in mucus. Avian influenza virus can survive for 100 days in distilled water at room temperature, and 200 days at . The avian virus is inactivated more quickly in manure, but can survive for up to 2 weeks in feces on cages. Avian influenza viruses can survive indefinitely when frozen.
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In contrast, a high-spin d8 transition metal complex is usually octahedral, substitutionally labile, with two unpaired electrons. Jahn-Teller effect is the geometrical distortion of non-linear molecules under certain situations. Any non-linear molecule with a degenerate electronic ground state will undergo a geometrical distortion that removes that degeneracy. This has the effect of lowering the overall energy.
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Failure to perform all of these steps correctly can lead to residual contamination remaining on endoscopes. In the UK, stringent guidelines exist regarding the decontamination and disinfection of flexible endoscopes, the most recent being CfPP 01–06, released in 2013 Rigid endoscopes, such as an Arthroscope, can be sterilized in the same way as surgical instruments, whereas heat labile flexible endoscopes cannot.
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The chemical structure of trimethylglycine The original betaine, N,N,N-trimethylglycine, was named after its discovery in sugar beet (Beta vulgaris subsp. vulgaris) in the nineteenth century.DNA Methylation and Complex Human Disease, Michel Neidhart It is a small N-trimethylated amino acid. It is a zwitterion, which cannot isomerize because there is no labile hydrogen atom attached to the nitrogen atom.
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Algae is under development for use in biofuels. Researchers in Singapore were working on GM jatropha for biofuel production. Syngenta has USDA approval to market a maize trademarked Enogen that has been genetically modified to convert its starch to sugar for ethanol. Some trees have been genetically modified to either have less lignin, or to express lignin with chemically labile bonds.
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Phospholipase C (, lipophosphodiesterase I, Clostridium welchii alpha-toxin, Clostridium oedematiens beta- and gamma-toxins, lipophosphodiesterase C, phosphatidase C, heat-labile hemolysin, alpha-toxin) is an enzyme with systematic name phosphatidylcholine cholinephosphohydrolase. This enzyme catalyses the following chemical reaction : a phosphatidylcholine + H2O \rightleftharpoons 1,2-diacyl-sn-glycerol + phosphocholine The bacterial enzyme is a zinc protein. It also acts on sphingomyelin and phosphatidylinositol.
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Cooking treatments do not lead to variance in total protein and carbohydrate content. Soaking and cooking of dry seeds possibly induces chemical modification of protein-fibre complexes, which leads to an increase in crude fiber content. Thus, cooking can increase protein quality by inactivating or destroying heat-labile antinutritional factors. Cooking also increases protein digestibility, essential amino acid index, and protein efficiency ratio.
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Dinaric calcareous silver fir forests have an open structure which is environmentally sensible. As storms of bora and scirocco type are common on the coastal dinaric mountains, wind plays a great role in the formation of the highly labile structure in the pure silver fir communities. Silver firs can reach up to on limestone and trunk diameters of have been observed.
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Conversely, a German study done in vivo found that VEGF concentrations actually decreased after a 25% reduction in oxygen intake for 30 minutes. HIF1 alpha and HIF1 beta are constantly being produced but HIF1 alpha is highly O2 labile, so, in aerobic conditions, it is degraded. When the cell becomes hypoxic, HIF1 alpha persists and the HIF1alpha/beta complex stimulates VEGF release.
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The ligands employed are usually labile i.e. they can be displaced easily. Though the ligand plays no direct role in the reaction the presence of a ligand has its advantages. The ligand protects the Cu ion from interactions leading to degradation and formation of side products and also prevents the oxidation of the Cu(I) species to the Cu(II).
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And he can be declared crazy after some bribe money have been paid. Creative, nonordinary, talented people have labile (as scientists say) nervous system, movable psychics. And they can be declared not quite normal mentally and, perhaps, even dangerous." Sergei Shishkov, the key lawyer of the Serbsky Center, also disagreed with Vinogradov, "We are unlikely to return to the Soviet mental health act.
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A number of bi- as well as terthiophenes exist naturally, invariably with substituents at the positions flanking sulfur. In terms of the biosynthesis, bithiophenes are proposed to be derived from polyacetylenic precursors, which in turn are the products of dehydrogenation of oleic acid. According to some hypotheses, these polyalkynes form labile 1,2-dithiins via a reaction with H2S2 or its equivalent..
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Both histidines coordinate with copper through 3-nitrogen. Copper-H2O bond is the longest coordinate bond; it is labile and can be replaced by a substrate molecule. Tyr272 forms a dimer with a cysteine (Cys228) through an ortho carbon of tyrosine and the sulfur atom of cysteine, which is supported by X-ray crystallography studies. The Tyr-Cys cross-link decreases the structural flexibility of Tyr272.
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The first d electron count (special version of electron configuration) with the possibility of holding a high spin or low spin state is octahedral d4 since it has more than the 3 electrons to fill the non-bonding d orbitals according to ligand field theory or the stabilized d orbitals according to crystal field splitting. ;d4: :Octahedral high-spin: 4 unpaired electrons, paramagnetic, substitutionally labile.
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Two can be classified as protein halocins: HalH1 and HalH4; the molecular masses of the remaining halocins have yet to be elucidated. Halocin H1 is produced by Hfx. mediterranei M2a (formerly strain Xia3), isolated from a solar saltern near Alicante, Spain. It is a 31 kDa protein that is heat-labile, loses activity when desalted, and exhibits a broad range of inhibition within the haloarchaea.
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In the midst of this development of the novel, other trends were taking place. The novel of sentiment was beginning in the 1760s and would experience a brief period of dominance. This type of novel emphasized sympathy. In keeping with the philosophy of Hartley (see above), the sentimental novel concentrated on characters who are quickly moved to labile swings of mood and extraordinary empathy.
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Dibenzothiophene is prepared by the reaction of biphenyl with sulfur dichloride in the presence of aluminium chloride.L. H. Klemm, Joseph J. Karchesy "Dibenzothiophene from biphenyl and derivatives" Journal of Heterocyclic Chemistry, 1978, Volume 15 Issue 4, Pages 561 - 563. Reduction with lithium results in scission of one C-S bond. S-oxidation occurs to give the sulfone, which is more labile than the parent dibenzothiophene.
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These intermediates almost always react with α selectitivity in alkylation reactions, the exception to the rule being anions of ortho-tolyl nitriles. (5)File:Tolunitrile.png Formation of cyanohydrins from carbonyl compounds renders the former carbonyl carbon acidic. After protection of the hydroxyl group, cyanohydrins can function essentially as masked acyl anions. Because ester protecting groups are base labile, mild bases must be employed with ester-protected cyanohydrins.
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Reactions of metal-pincer complexes are localized at three sites perpendicular to the plane of the pincer ligand, although in some cases one arm is hemi-labile and an additional coordination site is generated transiently. Early examples of pincer ligands (not called such originally) were anionic with a carbanion as the central donor site and flanking phosphine donors; these compounds are referred to as PCP pincers.
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Theoretical studies suggest that thiepine would eliminate a sulfur atom to form benzene. The intermediate is this process is the bicycle thianorcaradiene. In the complex with (η4-C6H6S)Fe(CO)3, the ring is stable. Nishino, K.; Takagi, M.; Kawata, T.; Murata, I.; Inanaga, J.; Nakasuji, K., "Thiepine-iron tricarbonyl: stabilization of thermally labile parent thiepine by transition metal complexation", J. Am. Chem. Soc.
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Their main use is for preconcentration of metal ions in a dilute solution.Apte, S. C.; Batley, G. E., "Trace metal speciation of labile chemical species in natural waters and sediments: non-electrochemical approaches", IUPAC Ser. Anal. Phys. Chem. Environ. Syst. 1995, 3, 259-306.Garg, B. S.; Sharma, R. K.; Bhojak, N.; Mittal, S., "Chelating Resins and Their Applications in the Analysis of Trace Metal Ions", Microchem.
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During this procedure the pores are formed by the carbon dioxide molecules that abandon the polymer, resulting in a sponge-like structure. The main problems resulting from such a technique are caused by the excessive heat used during compression molding (which prohibits the incorporation of any temperature labile material into the polymer matrix) and by the fact that the pores do not form an interconnected structure.
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A jar of Durkee meat tenderizer containing bromelain. Along with papain, bromelain is one of the most popular proteases to use for meat tenderizing. Bromelain is sold in a powdered form, which is combined with a marinade, or directly sprinkled on the uncooked meat. Cooked or canned pineapple does not have a tenderizing effect, as the enzymes are heat-labile and denatured in the cooking process.
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The pyridine adduct of the cobalt(II) complex Co(salen)(py) (salcomine) has a square-pyramidal structure; it can act as a dioxygen carrier by forming a labile, octahedral O2 complex. The name “salen ligands” is used for tetradentate ligands which have similar structures. For example, in salpn there is a methyl substituent on the bridge. It is used as a metal deactivation additive in fuels.
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Consequently, DOM becomes less reactive as it is continually reworked. Said another way, the DOM pool becomes less labile and more refractory with degradation. As it is reworked, organic compounds are continually being added to the bulk DOM pool by physical mixing, exchange with particles, and/or production of organic molecules by the consumer community.Ogawa, H., Amagai, Y., Kioke, I., Kaiser, K., and Benner, R. (2001).
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Various virulence factors have been suggested as being involved in the pathogenicity of E. rhusiopathiae. The presence of a hyaluronidase and neuraminidase has been recognized, and neuraminidase was shown to play a significant role in bacterial attachment and subsequent invasion into host cells. The role of hyaluronidase in the disease process is controversial. The presence of a heat-labile capsule has been reported as important in virulence.
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The major commercial application of organotin compounds is in the stabilization of PVC plastics. In the absence of such stabilizers, PVC would otherwise rapidly degrade under heat, light, and atmospheric oxygen, resulting in discolored, brittle products. Tin scavenges labile chloride ions (Cl−), which would otherwise initiate loss of HCl from the plastic material. Typical tin compounds are carboxylic acid derivatives of dibutyltin dichloride, such as the dilaurate.
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There is limited protein sequence coverage by identified peptides, loss of labile PTMs, and ambiguity of the origin for redundant peptide sequences. Recently the combination of bottom-up and top-down proteomics, so called middle-down proteomics, is receiving a lot of attention as this approach not only can be applied to the analysis of large protein fragments but also avoids redundant peptide sequences.
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Polysilicon hydrides are much less thermally stable than the corresponding alkanes (CnH2n+2). They are kinetically labile, with their decomposition reaction rate increasing with increases in the number of silicon atoms in the molecule. Consequently, the preparation and isolation of polysilicon hydrides is difficult for species containing more than a few silicon atoms.W. W. Porterfield Inorganic Chemistry: A Unified Approach, Academic Press (1993) p.
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Alternatively, some nuclei in a chemical system are labile and exchange between non-equivalent environments. A more specific example of this case is presented in the section Chemical Exchange Magnetization transfer. In either case, magnetization transfer techniques probe the dynamic relationship between two or more distinguishable nuclei populations, in so far as energy exchange between the populations can be induced and measured in an idealized NMR experiment.
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The concentration of the catalyst and the oxidant were found to be strongly affecting the oxidation process. Many related complexes with cis labile sites are active catalysts. Most complexes were found to undergo degradation in a few hours. Higher stability of the molecular catalyst may be achieved using robust clathrochelate ligands that stabilize high oxidation states of iron and prevent rapid degradation of the catalyst.
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Fluorescing scorpion Spiders fluoresce under UV light and possess a huge diversity of fluorophores. Remarkably, spiders are the only known group in which fluorescence is "taxonomically widespread, variably expressed, evolutionarily labile, and probably under selection and potentially of ecological importance for intraspecific and interspecific signaling". A study by Andrews et al. (2007) reveals that fluorescence has evolved multiple times across spider taxa, with novel fluorophores evolving during spider diversification.
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However, when the first-order association is only indirectly activated (through the associative chain), it appears that there is not sufficient stimulation to kick off cellular processes which would place it in a labile state, so it remains fixed.Debiec, J., Doyere, V., Nader, K., LeDoux, J.E. (February 28, 2006). Directly reactivated, but not indirectly reactivated, memories undergo reconsolidation in the amygdala. PNAS, Volume 103, Number 9, 3428-3433.
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Pyrite takes the place of phyllosilicates in some BST deposits. Labile tissues are associated with framboids, as they produced many nucleation sites due to the rapid production of sulfides (perhaps by sulfur-reducing bacteria); recalcitrant tissues are associated with euhedra. It's not entirely clear whether pyrite is involved in the preservation of the anatomy, or whether they simply replace carbon films later in diagenesis (in the same fashion as phyllosilicates).
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The compound is polymeric in the crystalline form. Half of the Co2+ ions are bound to the EDTA2− and the other Co2+ ions are bound to four water ligands as well as carboxylate ligands on the [Co(EDTA)]2− entity. In aqueous solution, depolymerization occurs to give [Co(EDTA)]2− and [Co(H2O)6]2+ ions, each of which is kinetically labile and has a high affinity for cyanide.
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Relief efforts by the Indian Navy in Chennai In the Lower Himalayas, landslides are common. The young age of the region's hills result in labile rock formations, which are susceptible to slippages. Short duration high intensity rainfall events typically trigger small scale landslides while long duration low intensity rainfall periods tend to trigger large scale catastrophic landslides. Rising population and development pressures, particularly from logging and tourism, cause deforestation.
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Fluids that would be damaged by heat, irradiation or chemical sterilization, such as drug solution, can be sterilized by microfiltration using membrane filters. This method is commonly used for heat labile pharmaceuticals and protein solutions in medicinal drug processing. A microfilter with pore size of usually 0.22 µm will effectively remove microorganisms. Some staphylococcal species have, however, been shown to be flexible enough to pass through 0.22 µm filters.
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Some people with type 1 diabetes experience dramatic and recurrent swings in glucose levels, often occurring for no apparent reason; this is called "unstable diabetes", "labile diabetes" or "brittle diabetes". The results of such swings can be irregular and unpredictable hyperglycemias, sometimes involving ketoacidosis, and sometimes serious hypoglycemias. Brittle diabetes occurs no more frequently than in 1% to 2% of diabetics. Type 1 diabetes is associated with alopecia areata (AA).
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Temperature controlled furnace The loss on ignition is reported as part of an elemental or oxide analysis of a mineral. The volatile materials lost usually consist of "combined water" (hydrates and labile hydroxy-compounds) and carbon dioxide from carbonates. It may be used as a quality test, commonly carried out for minerals such as iron ore. For example, the loss on ignition of fly ash consists of contaminant unburnt fuel.
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When a diol or more than one equivalent of alcohol is used, acetoxydialkoxyperiodinane is formed instead. Due to the labile nature of this particular periodinane, oxidation occurs much faster. :Oxidation by Dess-Martin-Periodinan Schreiber and coworkers have shown that water increases the rate of the oxidation reaction. Dess and Martin had originally observed that the oxidation of ethanol was increased when there was an extra equivalent of ethanol.
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The parent sulfine H2CSO is very labile, whereas substituted derivatives are more conveniently isolated. One example is syn-propanethial-S- oxide which is produced from Allicin and is responsible for eye-watering effects of cutting onions. Another example is diphenylsulfine, obtained by oxidation of thiobenzophenone: :(C6H5)2C=S + [O] → (C6H5)2C=S=O Structure of diphenylsulfine. Selected distances and angles: rS=O = 1.468, rC=S = 1.612 Å,
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Experiments have shown that targeted negative memories are recalled less vividly and with less emotion after treatments with EMDR. Skin conductance responses, a measure of stress and arousal, have also shown lower levels when negative memories treated with EMDR were brought to mind. A possible mechanism for EMDR has been proposed. As memories are recalled they enter a labile state, where they become vulnerable to being forgotten again.
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As early as 1237, raw silk was documented to be brought to Zurich from Como via Walenstadt. At that time, shipments were transported in primitive vehicles on poorly paved roads, narrow bridle paths, and dangerously labile, unstable footbridges. Back then, transporting silk was much more laborious and hazardous than it is today. To reach Chur and adjacently Walenstadt, traders were forced to pass the Septimer Pass and the old imperial road.
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An oxygen minimum zone (OMZ) is characterized as an oxygen-deficient layer in the world oceans. Typically found between 200m to 1500m deep below regions of high productivity, such as the western coasts of continents. OMZs can be seasonal following the spring-summer upwelling season. Upwelling of nutrient- rich water leads to high productivity and labile organic matter, that is respired by heterotrophs as it sinks down the water column.
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GM1 (monosialotetrahexosylganglioside) the "prototype" ganglioside, is a member of the ganglio series of gangliosides which contain one sialic acid residue. GM1 has important physiological properties and impacts neuronal plasticity and repair mechanisms, and the release of neurotrophins in the brain. Besides its function in the physiology of the brain, GM1 acts as the site of binding for both cholera toxin and E. coli heat-labile enterotoxin (Traveller's diarrhea).
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Trifluoroacetic acid is a corrosive acid but it does not pose the hazards associated with hydrofluoric acid because the carbon-fluorine bond is not labile. Only if heated or treated with ultrasonic waves will it decompose into hydrofluoric acid. TFA is harmful when inhaled, causes severe skin burns and is toxic for aquatic organisms even at low concentrations. TFA's reaction with bases and metals, especially light metals, is strongly exothermic.
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Role of photoreactions in the formation of biologically labile compounds from dissolved organic matter. Limnol. Oceanogr. 42, 1307–1316. doi: 10.4319/lo.1997.42.6.1307Mopper, K., Kieber, D. J., and Stubbins, A. (2015). “Marine photochemistry of organic matter,” in Biogeochemistry of Marine Dissolved Organic Matter, eds C. A. Carlson and D. A. Hansell (Amsterdam: Elsevier), 389–450. doi: 10.1016/B978-0-12-405940-5.00008-X and (4) biotic degradation by heterotrophic marine prokaryotes.
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251x251px Depending on the microorganism PRAI's structure can vary between a mono-functional enzyme (monomeric and labile) or a stable bi-functional dimeric enzyme. Within Saccharomyces cerevisiae, Bacillus subtilis, Pseudomonas putida, and Acinetobacter calcoaceticus the enzyme is monmeric. In contrast, in hyperthermophile Thermotoga maritima, Escherichia coli (Fig. 5), Salmonella typhimurium, and Aerobacter aerogenes, and Serratia marcescens, it is a bi-functional enzyme with indoleglycerol phosphate synthase as the paired enzyme.
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Regarding safety concern, platinum cannot be absorbed by the body. Platinum has widely been used in numerous kinds of medical implants, such as dental alloys, aneurysm coils, medical device electrodes, coronary stents and catheters. Allergy of platinum metal in human has rarely been reported. Only platinum compounds which possess labile leaving groups coordinated to platinum, such as complex halogenated platinum salts or cisplatin, show hypersensitivity and/or toxicity to human.
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A protic solvent is a solvent that has a hydrogen atom bound to an oxygen (as in a hydroxyl group), a nitrogen (as in an amine group), or fluoride (as in hydrogen fluoride). In general terms, any solvent that contains a labile H+ is called a protic solvent. The molecules of such solvents readily donate protons (H+) to solutes, often via hydrogen bonding. Water is the most common protic solvent.
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Stroke risk assessment should always include an assessment of bleeding risk. This can be done using validated bleeding risk scores, such as the HEMORR2HAGES or HAS-BLED scores. The HAS- BLED score is recommended in guidelines, to identify the high risk patient for regular review and followup and to address the reversible risk factors for bleeding (e.g. uncontrolled hypertension, labile INRS, excess alcohol use or concomitant aspirin/NSAID use).
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Bis-tris methane, also known as BIS-TRIS or BTM, is a buffering agent used in biochemistry. Bis-tris methane is an organic tertiary amine with labile protons having a pKa of 6.46 at 25 °C. It is an effective buffer between the pH 5.8 and 7.2. Bis-tris methane binds strongly to Cu and Pb ions as well as, weakly, to Mg, Ca, Mn, Co, Ni, Zn and Cd.
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Therefore, by replacing an amino acid, the protein may maintain a higher level of activity. For example, aspartic acid is chemically similar to phospho-serine. Therefore, when an aspartic acid replaces a serine, it is a phosphomimetic of phospho-serine and can make the protein always in its phosphorylated form. Phosphonate-based compounds have been used as phosphotyrosine analogues, as they are less enzyme labile and are physiologically more stable.
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As mentioned above the microbial pump is responsible for the production of refractory DOM which is unavailable for biodegradation and remains dissolved in the oceans for thousands of years. The turnover of labile DOM organic material is quite high due to scarcity, this is important for the support of multiple trophic levels in the microbial community. The uptake and respiration of DOM by heterotrophs closes the cycle by producing CO2.
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All G protein α sub-units contain palmitate, which is a 16-carbon saturated fatty acid, that is attached near the N-terminus through a labile, reversible thioester linkage to a cysteine amino acid. It is this palmitoylation that allows the G protein to interact with membrane phospholipids due to the hydrophobic nature of the alpha sub-units. The gamma sub-unit is also lipid modified and can attach to the plasma membrane as well.
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A common way to synthesize an NHS-activated acid is to mix NHS with the desired carboxylic acid and a small amount of an organic base in an anhydrous solvent. A coupling reagent such as dicyclohexylcarbodiimide (DCC) or ethyl(dimethylaminopropyl) carbodiimide (EDC) is then added to form a highly reactive activated acid intermediate. NHS reacts to form a less labile activated acid. The group itself is usually written as SuO- or -OSu in chemical notation.
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Hydrogen atoms, with between one and zero electrons in a biological setting, diffract X-rays poorly and are effectively invisible under normal experimental conditions. Neutrons scatter from atomic nuclei, and are therefore capable of detecting hydrogen and deuterium atoms. Hydrogen atoms are routinely replaced with deuterium, which introduce a strong and positive scattering factor. It is often sufficient to replace only the solvent and labile hydrogen atoms in a protein crystal by vapor diffusion.
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It is the strain behind the deadly June 2011 E. coli outbreak in Europe. Severity of the illness varies considerably; it can be fatal, particularly to young children, the elderly or the immunocompromised, but is more often mild. Earlier, poor hygienic methods of preparing meat in Scotland killed seven people in 1996 due to E. coli poisoning, and left hundreds more infected. E. coli can harbour both heat-stable and heat-labile enterotoxins.
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Providing stove- top or solar autoclaves to rural medical centers has been the subject of several proposed medical aid missions. Because damp heat is used, heat-labile products (such as some plastics) cannot be sterilized this way or they will melt. Paper and other products that may be damaged by steam must also be sterilized another way. In all autoclaves, items should always be separated to allow the steam to penetrate the load evenly.
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In order to have these types of qualities, positive resist utilize polymers with labile linkers in their back bone that can be cleaved upon irradiation or using a photo- generated acid to hydrolyze bonds in the polymer. A polymer that decomposes upon irradiation to a liquid, or more soluble product is referred to as a positive tone resist. Common functional groups that can be hydrolyzed by photo-generated acid catalyst include polycarbonates and polyesters.
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The type species, T. taqueti, was described by Eric Buffetaut in 1974. A second species, T. oblita, was named from Madagascar in 1979, but was renamed Miadanasuchus in 2009. Trematochampsa gives its name to the Trematochampsidae, a poorly known group of fossil crocodiles. However, the labile phylogenetic position of Trematochampsa in many studies has been attributed to character conflict, leading many authors to exclude this genus from many cladistic analyses, but Sertich et al.
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See FDA index page for NDA 203565 for updates and further information. Iron Isomaltoside 1000 (Trade name Monofer) is a newer formulation of parenteral iron that has a matrix structure that results in very low levels of free iron and labile iron. It can be given at high doses – 20 mg/kg in a single visit – no upper dose limit. This formulation has the benefit of giving a full iron correction in a single visit.
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The TET active site contains a highly conserved triad motif, in which the catalytically-essential Fe(II) is held by two histidine residues and one aspartic acid residue (see Figure). The triad binds to one face of the Fe center, leaving three labile sites available for binding α-KG and O2 (see Figure). TET then acts to convert 5-methylcytosine to 5-hydroxymethylcytosine while α-ketoglutarate is converted to succinate and CO2.
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In the presence of excess of triphenylphosphine, RuCl2(PPh3)3 binds a fourth phosphine to give black RuCl2(PPh3)4. The triphenylphosphine ligands in both the tris(phosphine) and tetrakis(phosphine) complexes are labile and are readily substituted by other ligands. Notably, the tetrakis(phosphine) complex is a precursor to the Grubbs catalysts.Georgios C. Vougioukalakis, Robert H. Grubbs "Ruthenium-Based Heterocyclic Carbene-Coordinated Olefin Metathesis Catalysts" Chem. Rev., 2010, volume 110, pp 1746–1787.
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The box represents a vacant (or extremely labile) coordination site. Step i involves binding of the monomer to the metal and step ii involves the migratory insertion step. These steps, which alternate from one side of the metal center to the other, are repeated many times for each polymer chain. The details of this mechanism can be used to explain the stereoregularity of the polymerisation of alkenes using Ziegler–Natta or metallocene catalysts.
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It, along with other labile viruses, can also persist longer in serum and tissue debris. Despite extensive vaccination in many regions, it remains a major disease of dogs. To prevent canine distemper, puppies should begin vaccination at 6-8 weeks of age and then continue getting the “booster shot” every 2-4 weeks until they are 16 weeks of age. Without the full series of shots, the vaccination does not provide protection against the virus.
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Polonium hydride (also known as polonium dihydride, hydrogen polonide, or polane) is a chemical compound with the formula PoH2. It is a liquid at room temperature, the second hydrogen chalcogenide with this property after water. It is very unstable chemically and tends to decompose into elemental polonium and hydrogen; like all polonium compounds, it is highly radioactive. It is a volatile and very labile compound, from which many polonides can be derived.
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Pottenger was a doctor whose 1932-1942 Pottenger Cat Study addressed the nutritive value of heat- labile elements — nutrients destroyed by heat and available only in raw foods. He used donated laboratory cats to test the potency of the adrenal extract hormones he was making. The adrenal glands of these cats were removed for the experiments, usually resulted their death. But Pottenger noted that most of the cats died during or following the operation.
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Guanitoxin is generally labile. It decomposes rapidly in basic solutions, but is relatively stable in neutral or acidic solutions (pH 3-5). When stored at -20˚C, it slowly undergoes hydrolysis giving (5S)-5-[(dimethylamino)methyl]-2-imino-1-imidazolidinol and monomethyl- phosphate, and more slowly, formation of (S)-1-(2-iminoimidazolidin-4-yl)-N,N-dimethylmethanamine. Furthemore, air evaporation of guanitoxin resulted in significant hydrolysis to (5S)-5-[(dimethylamino)methyl]-2-imino-1-imidazolidinol.
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Diamphotoxin is a toxin produced by larvae and pupae of the beetle genus Diamphidia. Diamphotoxin is a hemolytic, cardiotoxic, and highly labile single-chain polypeptide bound to a protein that protects it from deactivation. Diamphotoxin increases the permeability of cell membranes of red blood cells. Although this does not affect the normal flow of ions between cells, it allows all small ions to pass through cell membranes easily, which fatally disrupts the cells' ion levels.
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The characteristic anhydride bonds in polyanhydrides are water-labile (the polymer chain breaks apart at the anhydride bond). This results in two carboxylic acid groups which are easily metabolized and biocompatible. Biodegradable polymers, such as polyanhydrides, are capable of releasing physically entrapped or encapsulated drugs by well-defined kinetics and are a growing area of medical research. Polyanhydrides have been investigated as an important material for the short-term release of drugs or bioactive agents.
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In the complex of Gd3+ and DTPA5− the gadolinium ion is 9-coordinate, surrounded by the 3 nitrogen atoms and 5 oxygen atoms from the carboxylate groups. The ninth coordination site is occupied by a water molecule.A. Dean Sherry, Peter Caravan, Robert E. Lenkinski "Primer on Gadolinium Chemistry" J. Magnetic Resonance 2009, volume 30, p1240–1248. This water molecule is labile and exchanges rapidly with water molecules in the immediate vicinity of the gadolinium complex.
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PABPC4 is localized primarily to the cytoplasm. It is suggested that PABPC4 might be necessary for regulation of stability of labile mRNA species in activated T cells. PABPC4 was also identified as an antigen, APP1 (activated-platelet protein-1), expressed on thrombin-activated rabbit platelets. PABPC4 may also be involved in the regulation of protein translation in platelets and megakaryocytes or may participate in the binding or stabilization of polyadenylates in platelet dense granules.
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Refractory DOM can reach depths greater than 1000 m and circulates through the oceans over thousands of years. Over the course of a year, approximately 20 gigatons of photosynthetically-fixed labile and semilabile carbon is taken up by heterotrophs, whereas fewer than 0.2 gigatons of refractory carbon is consumed. Marine dissolved organic matter (DOM) can store as much carbon as the current atmospheric CO2 supply, but industrial processes are altering the balance of this cycle.
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The triflate ligand is labile, reflecting its low basicity. Trifluoromethanesulfonic acid exothermically reacts with metal carbonates, hydroxides, and oxides. Illustrative is the synthesis of Cu(OTf)2. :CuCO3 \+ 2 CF3SO3H → Cu(O3SCF3)2 \+ H2O + CO2 Chloride ligands can be converted to the corresponding triflates: :3 CF3SO3H + [Co(NH3)5Cl]Cl2 → [Co(NH3)5O3SCF3](O3SCF3)2 \+ 3 HCl This conversion is conducted in neat HOTf at 100 °C, followed by precipitation of the salt upon the addition of ether.
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Such chiral PTs in principle could be employed for detection or separation of chiral analytes. Poly(3-(perfluorooctyl)thiophene)s is soluble in supercritical carbon dioxide Oligothiophenes capped at both ends with thermally-labile alkyl esters were cast as films from solution, and then heated to remove the solublizing end groups. Atomic force microscopy (AFM) images showed a significant increase in long-range order after heating. Fluorinated polythiophene yield 7% efficiency in polymer-fullerene solar cells.
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Chemosphere 54, 695-709. Using SLMDs to passively collect metals over an extended period of time allows for trace metals to accumulate to detectable levels, which can give more accurate estimate of aquatic chemistry and contamination. SLMDs also have the advantage of being able to capture pulses of metal contamination that might otherwise go undetected when using grab samples. SLMDs are limited to the assessment of labile metals, and cannot be used to monitor for organic contaminants.
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Iron tetracarbonyl hydride was first produced by Hieber and Leutert by protonation of HFe(CO): :Fe(CO)5 \+ 2 OH− → HFe(CO) + HCO :HFe(CO) + H+ → H2Fe(CO)4 Since the compound is thermally labile and sensitive to light, ideal conditions in 1930's Munich called for winter nights. The early method was called the "polar night synthesis." Current procedures resemble that of Hieber and Leutert. The compound is generally purified by trap-to-trap distillation.
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The biological function of MPST remains unclear. It may be involved in cyanide detoxification, biosynthesis of thiosulfate, production of the signalling molecule hydrogen sulfide, or the degradation of cysteine. MPST reacts with 3-MP to convert a cysteinyl residue to the persulfide-containing intermediate: :RSH + HSCH2C(O)CO2− → RSSH + CH3C(O)CO2− The persulfide group is labile, and can transfer S to other groups, such as cyanide. It is also susceptible to reduction to release hydrogen sulfide.
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Upon treatment with typical organic ligands, manganese(II) undergoes oxidation by air to give Mn(III) complexes. Examples include [Mn(EDTA)]−, [Mn(CN)6]3−, and [Mn(acetylacetonate)3]. Triphenylphosphine forms a labile 2:1 adduct: :MnCl2 \+ 2 Ph3P → [MnCl2(Ph3P)2] Anhydrous manganese(II) chloride serves as a starting point for the synthesis of a variety of manganese compounds. For example, manganocene is prepared by reaction of MnCl2 with a solution of sodium cyclopentadienide in THF.
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In addition, reduction of the soil causes a shift in phosphorus from resilient to more labile forms. This could eventually increase the potential for phosphorus loss. This is of particular concern for the environmentally sound management of such areas, where disposal of agricultural wastes has already become a problem. It is suggested that the water regime of soils that are to be used for organic wastes disposal is taken into account in the preparation of waste management regulations.
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Subsolid personality is a personality type which lacks firmness and own identity. The want of a kernel of personality prevents co-ordination in the person's strivings. A subsolid person senses anxiously how the environment reacts on his or her doings; the person adopts the color of the environment and chooses or is influenced by the way of appearing that serves him or her best. The actions of the person lack consistency and the emotional life is labile.
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Generally, labile hypertension does not present any physical symptoms during fluctuations of blood pressure. Elevation and decrease of blood pressure reading usually occurs without intervention. However, if the normal resting pressure remains abnormally excessive, common signs and symptoms that are present include: Headache, Heart palpitations, Flushing, Tinnitus (ringing or buzzing noise in one or both ears), Weakness of body, Dizziness and diaphoresis. Some may describe the episodes as abrupt in onset such that they were not evoked by stress.
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This creates a redundance that makes possible the controlled oscillation of values above and below the dynamic homeostasis present in all living creatures. This is a kind of fast-responding, "short term memory" of the ground substance. Without this labile capacity, the system would quickly move to an energetic equilibrium, which would bring inactivity and death. :For its biochemical survival, every organism requires the ability to rapidly construct, destroy and reconstruct the constituents of the ground substance.
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Its reported anticancer mechanism is that it acts as a farnesyl transferase inhibitor. Dozens of semi-synthetic anticancer compounds have been made from dideoxyverticillin A. Dimeric derivatives are reported to have better anticancer activity. The enantioselective first total synthesis of (+)-11,11’-dideoxyverticillin A, the structure of which contains many sterically congested, contiguous stereogenic centers as well as acid- and base-labile and redox-sensitive functionality, was biosynthetically inspired and achieved with high levels of chemical sophistication.
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ESI-MS was initially developed by Fenn and colleagues for analysis of biomolecules. It depends on the formation of gaseous ions from polar, thermally labile and mostly non- volatile molecules and thus is completely suitable for a variety of lipids. It is a soft-ionization method that rarely disrupts the chemical nature of the analyte prior to mass analysis. Various ESI-MS methods have been developed for analysis of different classes, subclasses, and individual lipid species from biological extracts.
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Mitteilung Helvetica Chimica Acta Volume 54, Issue 2, Date: 1971, Pages: 710-734 M. Roth, P. Dubs, E. Götschi, A. Eschenmoser The method requires a base and a tertiary phosphine. The method is of some relevance to organic chemistry and has been notably applied in the vitamin B12 total synthesis. :Eschenmoser sulfur contraction.svg A base abstracts the labile hydrogen atom in the thioester, a sulfide anion is formed through an episulfide intermediate which is removed by the phosphine.
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Transition metal alkyne complexes are often formed by the displacement of labile ligands by the alkyne. For example, a variety of cobalt-alkyne complexes may be formed by reaction of the alkyne with dicobalt octacarbonyl.Kemmitt, R. D. W.; Russell, D. R.; "Cobalt" in Comprehensive Organometallic Chemistry I; Abel, E.W.; Stone, F.G.A.; Wilkinson, G. eds., 1982, Pergamon Press, Oxford. : Co2(CO)8 \+ R2C2 → Co2(C2R2)(CO)6 \+ 2 CO Many alkyne complexes are produced by reduction of metal halides, e.g.
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GAPDH, like many other enzymes, has multiple functions. In addition to catalysing the 6th step of glycolysis, recent evidence implicates GAPDH in other cellular processes. GAPDH has been described to exhibit higher order multifunctionality in the context of maintaining cellular iron homeostasis, specifically as a chaperone protein for labile heme within cells. This came as a surprise to researchers but it makes evolutionary sense to re-use and adapt existing proteins instead of evolving a novel protein from scratch.
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The coupling of MS with LC systems is attractive because liquid chromatography can separate delicate and complex natural mixtures, which chemical composition needs to be well established (e.g., biological fluids, environmental samples, and drugs). Further, LC-MS has applications in volatile explosive residue analysis. Nowadays, LC-MS has become one of the most widely used chemical analysis techniques because more than 85% of natural chemical compounds are polar and thermally labile and GC- MS cannot process these samples.
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Some substances are stable in solution or some other "wild" form but cannot be isolated or captured without actually catalyzing their own polymerization or decomposition ("dissolving in their own tears"). For example, a molecule containing a carboxylic acid moiety and an acid labile moiety might be stable when initially prepared as the salt (e.g., barium prephenate) but unstable as the free acid (prephenic acid). These have been named "chemical squonks" as a nod to the creature.
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Many of the reactions of squaric acid involve the OH groups. The molecule behaves as a strong dicarboxylic acid. It is stronger acid than typical carboxylic acids. :C4O2(OH)2 → [C4O3(OH)]- \+ H+ pK = 1.5 :[C4O3(OH)]- → [C4O4]2- \+ H+ pK = 3.5 The OH groups are labile in squaric acid. It forms a dichloride with thionyl chloride: :C4O2(OH)2 \+ 2 SOCl2 → C4O2Cl2 \+ 2 HCl + 2 SO2 The chlorides are good leaving groups, remininscent of acid chlorides.
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Chonburi, Thailand, cutting the beards and removing barnacles from Asian green mussels P. viridis is harvested in the Indo-Pacific region as a food source due to its fast growth. However, it can harbor deadly Saxitoxin produced by the dinoflagellates that it feeds upon. It can also be used as a biomonitor to indicate pollution caused by heavy metals, organochlorides and petroleum products. Mussels that are in contaminated areas have labile lysosomal membranes due to metal-induced stress.
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RNA thermometers regulate gene expression in response to temperature allowing pathogens like Yersinia to switch on silent genes after entering the host organism. Usually, RNA thermometers are located in the 5'UTR, but an intergenic RNA thermometer was found in Yersinia pseudotuberculosis. The LcrF RNA thermometer together with the termo-labile YmoA protein activates synthesis of the most crucial virulence activator LcrF (VirF). The RNA thermosensor sequence is 100% identical in all human pathogenic Yersinia species.
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A mass deposition of Pyrosoma atlanticum carcasses were found along an oil pipeline in West Africa in 2006. Jelly-falls are marine carbon cycling events whereby gelatinous zooplankton, primarily cnidarians, sink to the seafloor and enhance carbon and nitrogen fluxes via rapidly sinking particulate organic matter. These events provide nutrition to benthic megafauna and bacteria. Jelly-falls have been implicated as a major “gelatinous pathway” for the sequestration of labile biogenic carbon through the biological pump.
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Furthermore, xenoestrogens expose fish to CYP1A inducers through inhibiting a putative labile protein and enhancing the Ah receptor, which has been linked to epizootics of cancer and the initiation of tumors. The induction of CYP1A has been established to be a good bioindicator for xenoestrogen exposure. In addition, xenoestrogens stimulate vitellogenin (Vtg), which acts as a nutrient reserve, and Zona readiata proteins (Zrp), which forms eggshells. Therefore, Vtg and Zrp are biomarkers to exposure for fish.
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S. rivulatus, like other rabbitfish, has venom glands associated with the spines in the fins and these spines can envenomate a human if the fish is handled incorrectly. The effect is very painful but there are no records of fatalities. The venom is a heat labile protein and any site where the body has been envenomated should be treated at as high a temperature as possible, 43-46℃. Anyone so envenomated should also be treated for possible infection too.
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Minneapolis, MN: NCS, Inc. There are three facet scales within each of the Clinical Personality Patterns and Severe Personality Pathology scales. Each facet scale is thought to help identify the key descriptive components of each personality scale, making it easier to evaluate slight differences in symptom presentations between people with elevated scores on the same personality scale. For instance, two profiles with an elevated score on the Borderline scale may have differences in their Temperamentally Labile facet scale scores.
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The melting point of crystallized honey is between , depending on its composition. Below this temperature, honey can be either in a metastable state, meaning that it will not crystallize until a seed crystal is added, or, more often, it is in a "labile" state, being saturated with enough sugars to crystallize spontaneously.Root, p. 355 The rate of crystallization is affected by many factors, but the primary factor is the ratio of the main sugars: fructose to glucose.
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Porous organosilicate materials are usually obtained by a two-step procedure where the first step consists of the co-deposition of a labile organic phase (known as porogen) together with an organosilicate phase resulting in an organic-inorganic hybrid material. In the second step, the organic phase is decomposed by UV curing or annealing at a temperature of up to 400°C, leaving behind pores in the organosilicate low-κ materials. Porous organosilicate glasses have been employed since the 45 nm technology node.
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Memory reconsolidation is the process of previously consolidated memories being recalled and actively consolidated. It is a distinct process that serves to maintain, strengthen and modify memories that are already stored in the long-term memory. Once memories undergo the process of consolidation and become part of long-term memory, they are thought of as stable. However, the retrieval of a memory trace can cause another labile phase that then requires an active process to make the memory stable after retrieval is complete.
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Metal cations in the aqueous feed raffinate are generally solvated by coordinating water molecules through the donor oxygen atoms to form aquo ions [M(H2O)_{n}]^{3+} (n = 4-9) . The complexation of a metal ion implies therefore the replacement of the coordinated water molecules with the respective ligands. The speed of this substitution plays a crucial role in the complexation kinetics and the following extraction processes. The replacement can be slow for an inert complex or rapid for a labile complex.
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To maximize potential of the two drives, Schiller argues, one cannot suffocate or limit the other. The perfection of the sense drive would consist in maximizing changeability and maximizing extensity. This is the development of receptivity, through which man presents more "surface" to phenomena of the world. "The more facets his receptivity develops, the more labile it is, and the more surface it presents to phenomena, so much more world does man apprehend, and all the more potentialities does he develop in himself".
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Reductive dehalogenation is the removing of halogen atoms from a molecule. However, the traditional method for dehalogenation uses stoichiometric organotin reagents, such as tributyltin hydride. While this reaction is powerful with high functional group tolerance, organotin reagents are highly toxic. The cleavage of activated and reductively labile functional groups including sulfoniums and halogens is the earliest application of photoredox catalysis to organic synthesis, but early attempts were limited by the need for specific substrates or by the formation of dimeric coupling products.
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The active site contains a highly conserved 2-His-1-carboxylate (HXD/E...H) amino acid residue triad motif, in which the catalytically-essential Fe(II) is held by two histidine residues and one aspartic acid/glutamic acid residue. The N2O triad binds to one face of the Fe center, leaving three labile sites available on the octahedron for binding αKG and O2. A similar facial Fe-binding motif, but featuring his-his-his array, is found in cysteine dioxygenase.
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Other thermal and non-thermal processes have been developed to pasteurize foods as a way of reducing the effects on nutritional and sensory characteristics of foods and preventing degradation of heat-labile nutrients. Pascalization or high pressure processing (HPP) and pulsed electric field (PEF) are examples of these non-thermal pasteurization methods that are currently commercially utilized. Microwave volumetric heating (MVH) is the newest available pasteurization technology. It uses microwaves to heat liquids, suspensions, or semi-solids in a continuous flow.
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Elevated TLR4 expression, associated with minor rs7873784(C) allele, in this context could be beneficial for favorable prognosis in appropriate cancer patients. Similar considerations could be applied to TLR4-mediated regulation of microbiota in case of chronic periodontitis where the reduced risk of progression was also associated with rs7873784(C) variant. TLR4 recognition of mycobacterial cell wall components and heat-labile soluble mycobacterial factor involved in the initiation of innate responses against tuberculosis may link TLR4 polymorphisms to modulation of tuberculosis susceptibility.
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Furthermore, C. Botulinum C3 ADP-ribosylates GTP- binding proteins Rho and Ras, and Pertussis toxin ADP-Ribosylates Gi, Go, and Gt. Diphtheria toxin ADP-ribosylates ribosomal elongation factor EF-2, which attenuates protein synthesis. There are a variety of bacteria which employ bAREs in infection: CARDS toxin of Mycoplasma pneumoniae, cholera toxin of vibrio cholera; heat-labile enterotoxin of E.Coli; Exotoxin A of Pseudomonas aeruginosa; Pertussis toxin of B. Pertussis; C3 toxin of C. botulinum; and Diphtheria toxin of Corynebacterium diphtheriae.
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"Recent Advances in the Neurobiology of Anxiety Disorders: Implications for Novel Therapeutics." American Journal of Medical Genetics Part C, Seminars in Medical Genetics (2008) 148C:89–98. Work conducted with Karim Nader and Glenn Schafe triggered a wave of interest in the topic of memory reconsolidation,Nader K, Schafe GE, LeDoux JE (2000) Fear memories require protein synthesis in the amygdala for reconsolidation after retrieval. Nature 406:722-726 a process by which memories become labile and subject to change after being retrieved.
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Constantly dividing cells have a higher risk of becoming malignant and develop cancer, dividing uncontrollably.How chemotherapy works at cancerhelp.org This is why muscle cancer is very rare, even though muscle tissue accounts for ~50% of total body weight, since muscle cells are not constantly dividing cells, and therefore not considered labile. In addition, cytotoxic drugs, such as alkylating antineoplastic agents, used in treatment of cancer, work by inhibiting the proliferation of dividing cells, with the malignant cells as the desired target.
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This risk increases greatly once the INR exceeds 4.5. A number of risk scores exist to predict bleeding in people using warfarin and similar anticoagulants. A commonly used score (HAS-BLED) includes known predictors of warfarin-related bleeding: uncontrolled high blood pressure (H), abnormal kidney function (A), previous stroke (S), known previous bleeding condition (B), previous labile INR when on anticoagulation (L), elderly as defined by age over 65 (E), and drugs associated with bleeding (e.g., aspirin) or alcohol misuse (D).
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Chut saves the childish features of character forever: he is foolish, playful, joking and emotionally labile. This spirit likes to make fun of the guests: to hide somebody's hat, to spill the beans and peas (and then gather them again at night). If Chut lives in the house, the host must feed him with ritual (and, at the same time, children's) food: fried eggs with (). Belarusians usually eat such kind of food on weddings, baptism, Kupala Night, Trinity Holiday and young women rituals.
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There is no need to watch for a peak between enzyme activity and percent disruption. Since nitrogen bubbles are generated within each cell, the same disruptive force is applied uniformly throughout the sample, thus ensuring unusual uniformity in the product. Cell- free homogenates can be produced. The technique is used to homogenize cells and tissues, release intact organelles, prepare cell membranes, release labile biochemicals, and produce uniform and repeatable homogenates without subjecting the sample to extreme chemical or physical stress.
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However, others directly refute this notion that parity is a labile trait. In their critique, they show that ancestral state reconstruction analyses are reliant on the underlying phylogenetic information provided. The use of a maximum likelihood tree which is vulnerable to phylogenetic error may cause an artificial inflation of the number of viviparity to oviparity occurrences. Additionally, they state that the previous study does not take into account the morphological and behavioral modifications that would have to occur for reversion to occur.
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Mycorrhizas and nutrient cycling in ecosystems – a journey towards relevance? New Phytologist, 157: 475-492 it is generally thought that they stimulate free-living decomposer communities to increase activity by exuding labile energy substrates, a process termed priming. Recent lab experiments have shown that the presence of arbuscular mycorrhizal fungi increases losses of soil carbon compared to soils where arbuscular mycorrhizal fungi are excluded, and that the difference is greater under elevated CO2 when the abundance of arbuscular mycorrhizal fungi is greater.
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That exchange occurs at all illustrates the ability of some compounds to be labile (fast reactions) but also stable (high formation constants). The reaction rate is described as follows: ::rate = k2[M(CN)42−][CN−], where k2 120 M−1−s−1 The bimolecular kinetics implicate a so-called associative pathway. The associative mechanism of exchange entails rate-limiting attack of cyanide on [Pd(CN)4]2−, possibly with the intermediacy of a highly reactive pentacoordinate species [Pd(CN)5]3−.
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Her PhD project was on tautomers, isomers of molecules which differ only in the position of a labile hydrogen atom. Her doctoral supervisor was Martha Whiteley Her subsidiary subject was physics and this led to her research in physical organic chemistry and quantum mechanics. Following completion of her PhD she went on to complete a DSc. She was also the president of the UCL Chemical and Physical society during the 1976-1977 academic year, one of the oldest and most prestigious societies at the university.
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The Cophylinae are highly ecologically labile over evolutionary time: in several instances, phylogenetic relationships based on DNA sequence data clearly indicate repeated transitions from e.g. terrestrial to arboreal habits and back. This has resulted in extensive homoplasy in ecologically-related morphological traits among the frogs, which led also to taxonomic confusion when only sparse morphological data were available; a problem that has been mostly but not fully rectified by the increased availability of DNA sequence data. Among the repeated ecomorphs that have evolved is miniaturised body size.
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Gladiolin is a polyketide natural product produced by Burkholderia gladioli BCC0238 which is isolated from sputum of cystic fibrosis patients. It was found to be a novel macrolide antibiotic which presented an activity against Mycobacterium tuberculosis. Gladiolin is structurally much more stable than its analogue etnangien as an efficient myxobacterial RNA polymerase inhibitor due to the lack of highly labile hexaene moiety in gladiolin. The good activity and high stability of gladiolin offers it the potential for further development as an antibiotic against antibiotic-resistant M. tuberculosis.
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He was an undergraduate at the Hebrew University of Jerusalem. He carried out his M.Sc. studies with Manfred Ashner on the ecology of marine luminescent bacteria, and his Ph.D. (1947) with Aryeh Leo Olitzki on heat labile antigens of Shigella. During the 1948 Arab-Israeli war he served in the siege of Jerusalem in the Intelligence unit of the Jewish paramilitary organization Haganah, and in the Science corps. He did post doctoral studies with Sir Hans Krebs at Oxford, and Roger Stanier at UC Berkeley (1954–1956).
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Most methods of lipid extraction and isolation from biological samples exploit the high solubility of hydrocarbon chains in organic solvents. Given the diversity in lipid classes, it is not possible to accommodate all classes with a common extraction method. The traditional Bligh/Dyer procedure uses chloroform/methanol-based protocols that include phase partitioning into the organic layer. These protocols work relatively well for a wide variety of physiologically relevant lipids but they have to be adapted for complex lipid chemistries and low-abundance and labile lipid metabolites.
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Today, dinitrogen complexes are known for almost all the transition metals, accounting for several hundred compounds. They are normally prepared by three methods: # Replacing labile ligands such as H2O, H−, or CO directly by nitrogen: these are often reversible reactions that proceed at mild conditions. # Reducing metal complexes in the presence of a suitable coligand in excess under nitrogen gas. A common choice include replacing chloride ligands by dimethylphenylphosphine (PMe2Ph) to make up for the smaller number of nitrogen ligands attached than the original chlorine ligands.
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The main IGFBP-3 ligands in the circulation are IGF-1 and IGF-2, and the acid-labile subunit (ALS). The serum proteins transferrin, fibronectin, and plasminogen are also known to bind IGFBP-3. In the cell and tissue environment many other interactions have been described (see Table). Two unrelated cell-surface proteins have been designated as IGFBP-3 receptors: low density lipoprotein receptor-related protein 1 (LRP1), also known as alpha-2-macroglobulin receptor or type V TGFβ receptor and the transmembrane protein TMEM219.
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Cells prevent expression of the genotoxic mutation by either DNA repair or apoptosis; however, the damage may not always be fixed leading to mutagenesis. To assay for genotoxic molecules, researchers assay for DNA damage in cells exposed to the toxic substrates. This DNA damage can be in the form of single- and double-strand breaks, loss of excision repair, cross-linking, alkali- labile sites, point mutations, and structural and numerical chromosomal aberrations. The compromised integrity of the genetic material has been known to cause cancer.
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Two had never had a diagnosis of a mental illness, and one of the three women was noted to be "emotionally labile" and had had a suicide attempt but no hospitalization. It was noted that the mania was not caused by an electrolyte imbalance, but the exact cause was uncertain. According to Ogawa and Ueki, secondary mania has also been associated with caffeine consumption. A 43-year-old man, with no prior history of mental illness, reportedly switched to drinking 10 cups of coffee a day.
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When heated or UV-irradiated in tetrahydrofuran (THF) solution, Cr(CO)6 converts to Cr(CO)5(THF) with loss of one CO ligand. Similarly, heating a solution of Cr(CO)6 in an aromatic solvent results in replacement of three CO ligands: :Cr(CO)6 \+ C6H5R → Cr(CO)3(C6H5R) + 3 CO UV- irradiation of frozen solutions of chromium hexacarbonyl affords a variety of labile adducts. Such reactions proceed well with electron-rich arenes such as anisole. The products adopt a "piano-stool" structure.
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Churchill suffered from heart problems for several years, and died on Christmas Eve 1900 of heart failure in her sleep while staying at Osborne House on the Isle of Wight. She was found the following morning in her bed. Her body was transported to the mainland on 28 December, and was buried on 29 December 1900 at Finstock, Oxfordshire. Queen Victoria's personal physician, Sir James Reid, at first withheld the news of Churchill's death as he feared it would upset the frail and labile monarch.
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Some drugs have the capacity to bind with certain types of proteins that are carried in blood plasma. This is important as only drugs that are present in the plasma in their free form can be transported to the tissues. Drugs that are bound to plasma proteins therefore act as a reservoir of the drug within the organism and this binding reduces the drug's final concentration in the tissues. The binding between a drug and plasma protein is rarely specific and is usually labile and reversible.
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Therefore, the activation of C5 results in a transient binding site for C6. Hydrophobic sites are probably exposed upon C5 activation because C5b undergoes aggregation when C5 is converted to C5b in the absence of C6. Interactions between C5 and C6 or C5 and membranes are noncovalent. (In contrast, it is the labile thiol ester that permits covalent attachment between C3 and nucleophilic acceptors.) The proteolytic cleavage of C5 is the only known enzymatic event in assembly of the cytolytic membrane attack complex of complement.
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Some of these modifications would be the redevelopment of uterine glands to synthesize and secrete shell fibers, the restoration of the careful timing of oviposition due to eggshell thickness, etc. The degradation and loss of function of oviparous genes during viviparous evolution suggests that these genes would have to re- evolve in order for the reversion of this evolution to occur. Since this re- evolution is near impossible due to the complexity of oviparous reproductive mode, the simple labile characteristic of parity cannot be sufficiently supported.
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Advances in Hemp Research, Haworth Press, Binghamton, NY, pp. 131–151. in which individual plants bear both male and female flowers. (Although monoecious plants are often referred to as "hermaphrodites", true hermaphrodites – which are less common in Cannabis – bear staminate and pistillate structures together on individual flowers, whereas monoecious plants bear male and female flowers at different locations on the same plant.) Subdioecy (the occurrence of monoecious individuals and dioecious individuals within the same population) is widespread. Many populations have been described as sexually labile.
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This can decrease the rate of soil respiration temporarily, but the lysis of bacteria causes for a spike in resources for many other bacteria. This rapid increase in available labile substrates causes short-term enhanced soil respiration. Root respiration will increase with increasing soil moisture, especially in dry ecosystems; however, individual species' root respiration response to soil moisture will vary widely from species to species depending on life history traits. Upper levels of soil moisture will depress root respiration by restricting access to atmospheric oxygen.
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This ligand has been hypothesized to be a water molecule or an acetyl group in the surrounding area in the cell. Although the proximal nickel is labile and can be replaced with a Cu of Zn centre, experimental evidence suggests that activity of ACS is limited to the presence of nickel only. In addition, some studies have shown that copper can even inhibit the enzyme under certain conditions. The overall structure of the CODH/ACS enzyme consists of the CODH enzyme as a dimer at the centre with two ACS subunits on each side.
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Spray drying serves as a microencapsulation technique when an active material is dissolved or suspended in a melt or polymer solution and becomes trapped in the dried particle. The main advantages are the ability to handle labile materials because of the short contact time in the dryer and the operation is economical. In modern spray dryers the viscosity of the solutions to be sprayed can be as high as 300 mPa·s. Applying this technique, along with the use of supercritical carbon dioxide, sensitive materials like proteins can be encapsulated.
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Japanese giant salamander(Andrias japonicus) The multiple transitions among XY and ZW systems that occur in amphibians determine the sex chromosome systems to be labile in salamanders populations. By understanding the chromosomal basis of sex of those species, it is possible to reconstruct the phylogenetic history of those families and use more efficient strategies in their conservation. By using the ddRADseq method scientists found new sex-related loci in a 56 Gb genome of the family Cryptobranchidae. Their results support the hypothesis of female heterogamety of this species.
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Thiede and Eggli (2007), in their treatment of the family, describe 34 genera with about 1,410 species. The size of the genera varies considerably, from Sedum, the largest with 300–500 species, to the smallest, which are monotypic. Estimates of the number of species has varied between 1500 (Berger 1930) and 900 (Cronquist 1981). Molecular phylogenetics has shown that morphological characters and chromosome numbers are so labile in the family, with rampant polyploidy and aneuploidy, that they cannot be used reliably to infer evolution, even at low taxonomic levels, with few exceptions.
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The key component that enables in situ control of supramolecular architecture via the WLA is the use of hemilabile ligands. Hemilabile ligands are polydentate chelates that contain at least two different types of bonding groups, denoted X and Y (Figure 3). The first group (X) bonds strongly to the metal center, while the other group (Y) is weakly bonding and easily displaced by coordinating ligands or solvent molecules (Z). In this way, the substitutionally labile group (Y) can be displaced from, yet remain available for recoordination to, the metal center.
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Other examples of drugs dependent on CYP3A4 for their metabolism are escitalopram, warfarin, oxycodone, tramadol, and oxymorphone. The concentrations of these drugs may increase if they are used concomitantly with omeprazole. Omeprazole is also a competitive inhibitor of p-glycoprotein, as are other PPIs. Drugs that depend on an acidic stomach environment (such as ketoconazole or atazanavir) may be poorly absorbed, whereas acid-labile antibiotics (such as erythromycin which is a very strong CYP3A4 inhibitor) may be absorbed to a greater extent than normal due to the more alkaline environment of the stomach.
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As Wellmon observes, Goethe's concept of science is one in which "not only the object of observation changes and moves but also the subject of observation." Thus, a true science of vital nature would be based on an approach that was itself vital, dynamic, labile. The key for this is a living, direct, interactive experience (Erlebnis) involving the mind, but also higher faculties more participatory and Imaginative (Gemüt), not dissociative and separative (Sinn). Only since the 1970s have other mainstream scientists come to be interested in Goethe's more holistic-humanistic approach to experiments.
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Though proteobacteria display impressive acid tolerance, most retain a circumneutral cytoplasm to avoid denaturation of their acid-labile cell constituents. Archaea such as Ferroplasma acidiphilum, which oxidises ferrous iron, have a number of intracellular enzymes with an optimum similar to that of their external acidic environment. This may explain their ability to survive pH as low as 1.3. The differing cell membranes in archaea compared to the bacteria may hold part of the explanation; ether lipids that link isoprene, compared to proteobacteria's di-ester linkage, are central to the difference.
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By expressing the heme-sening protein in the target plasmodium falciparum parasite, Niles made it possible to monitor the levels of heme through changes in fluorescence. Niles used this to show that malarial parasites contain high levels of labile heme than anticipated. Additionally, Niles demonstrated that CRISPR could be used to disrupt parasite genes, which provides information about how parasites invade and replicate inside red blood cells. The Niles lab collect publicly available genomics and transcriptomics data of these parasites, then builds a sequence of technologies to enter parasites and manipulate when genes are expressed.
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In dilute aqueous solution, such as is commonly used for Enhanced Oil Recovery applications, polyacrylamide polymers are susceptible to chemical, thermal, and mechanical degradation. Chemical degradation occurs when the labile amide moiety hydrolyzes at elevated temperature or pH, resulting in the evolution of ammonia and a remaining carboxyl group. Thus, the degree of anionicity of the molecule increases. Thermal degradation of the vinyl backbone can occur through several possible radical mechanisms, including the autooxidation of small amounts of iron and reactions between oxygen and residual impurities from polymerization at elevated temperature.
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N-Hydroxylation of an amide bond was reported by Cramer et al. (1960), who found that N-hydroxy-2-acetylaminofluorene was formed in the intact rat upon administration of 2-acetylaminofluorene. Nevertheless, this finding cannot be considered direct proof of N-hydroxylation of an amide bond because, as the authors point out, the acetyl group is labile in their experiments, and hydroxylation of the amino group might have occurred. Glycine, formate, and the 2-carbon of serine were all found to be very quickly incorporated into hadacidin during its synthesis by Penicillium aurantioviolaceum.
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In some cases, a pancreas transplant can restore proper glucose regulation. However, the surgery and accompanying immunosuppression required may be more dangerous than continued insulin replacement therapy, so is generally only used with or some time after a kidney transplant. One reason for this is that introducing a new kidney requires taking immunosuppressive drugs such as cyclosporine, which allows the introduction of a new pancreas to a person with diabetes without any additional immunosuppressive therapy. However, pancreas transplants alone may be beneficial in people with extremely labile type 1 diabetes.
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Other parts of the amino acid molecules can be converted into glucose and used for fuel. When food protein intake is periodically high or low, the body tries to keep protein levels at an equilibrium by using the "labile protein reserve" to compensate for daily variations in protein intake. However, unlike body fat as a reserve for future caloric needs, there is no protein storage for future needs. Excessive protein intake may increase calcium excretion in urine, occurring to compensate for the pH imbalance from oxidation of sulfur amino acids.
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Absorption: Duloxetine is acid labile, and is formulated with enteric coating to prevent degradation in the stomach. Duloxetine has good oral bioavailability, averaging 50% after one 60 mg dose. There is an average 2-hour lag until absorption begins with maximum plasma concentrations occurring about 6 hours post dose. Food does not affect the Cmax of duloxetine, but delays the time to reach peak concentration from 6 to 10 hours. Distribution: Duloxetine is highly bound (>90%) to proteins in human plasma, binding primarily to albumin and α1-acid glycoprotein.
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One particular question that Pottenger addressed in his study had to do with the nutritive value of heat-labile elements – nutrients destroyed by heat and available only in raw foods. He applied the principles of nutrition and endocrinology early in his practice. Dr. Pottenger was a pioneer in using crude extracts of adrenal cortex as supplements to treat allergic states and exhaustion. In his treatment of respiratory diseases such as TB, asthma, allergies and emphysema, he always highlighted proper diet based on the principles discovered by Weston Price.
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It is strongly inhibited by the statins, a class of drugs based on a mold metabolite which, at least at one time, were the largest selling class of drugs in the world. Mevalonate is acted of by a series of 3 kinases to give the highly labile 1,2-diphosphomevalonate-3-phosphate, which is acted on by a lyase to give phosphate, CO2, and isopentenyl diphosphate. Isopentenyl diphosphate isomerase converts the latter to the less stable dimethylallyl diphosphate. Farnesyl diphosphate synthase takes one DMAPP and two IPP to give the C15 metabolite farnesyl diphosphate.
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Chloro(cyclopentadienyl)bis(triphenylphosphine)ruthenium(II) undergoes a variety of reactions often by involving substitution of the chloride. With phenylacetylene it gives the phenyl vinylidene complex: : (C5H5)(PPh3)2RuCl + HC2Ph + NH4[PF6] → [Ru(C:CHPh)(PPh3)2(C5H5)][PF6] + NH4Cl Displacement of one PPh3 by carbon monoxide affords a chiral compound. :(C5H5)(PPh3)2RuCl + CO → (C5H5)(PPh3)(CO)RuCl + PPh3 The compound can also be converted into the hydride: :(C5H5)(PPh3)2RuCl + NaOMe → (C5H5)(PPh3)2RuH + NaCl + CH2O A related complex is tris(acetonitrile)cyclopentadienylruthenium hexafluorophosphate, which has three labile MeCN ligands.
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Fromm cites evidence from neuroscience that aggression is "essentially defensive", arising in "phylogenetically programed brain areas" for fight or flight when an animal or person feels threatened. Fromm points out that "self-propelling aggressiveness" is seen in people with brain disease, but not in "normal brain functioning". The biologist E. O. Wilson, in On Human Nature (1978), argues that both Lorenz and Fromm are essentially wrong. He lists a variety of aggression categories, each separately subject to natural selection, and states that aggressive behavior is, genetically, one of the most labile of all traits.
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The S-N bond n sulfenamide are labile in a variety of ways. The sulfur atom tends to be the more electrophilic center of the S-N bond. Nucleophillic attack on sulfur can occur by amines, by thiols, and by alkyl-magnesium halides which leads to either new sulfenamide compounds or back to starting compounds such as sulfides and disulfides respectively. Both the nitrogen and sulfur atoms comprising the S-N bond in sulfenamides have lone pairs of electrons in their outer shells, one and two for nitrogen and sulfur respectively.
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The Si-O bond distance is typically about 1.65 Å.Paul D. Lickiss: The Synthesis and Structure of Organosilanols, Advances in Inorganic Chemistry Volume 42, 1995, Pages 147–262 In the solid state, silanols engage in hydrogen-bonding.Beckmann, J.; Dakternieks, D.; Duthie, A.; Larchin, M. L.; Tiekink, E. R. T.: Tert-butoxysilanols as model compounds for labile key intermediates of the sol-gel process: crystal and molecular structures of (t-BuO)3SiOH and HO[(t-BuO)2SiO]2H, Appl. Organomet. Chem. 2003, 17, 52–62. Most silanols have only one OH group, e.g. trimethylsilanol.
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DOM is smaller and tends to stay mixed within the euphotic zone of the water column. The labile DOM is easier for microbes to digest and recycle, allowing incorporation of carbon into biomass. As microbial biomass increases due to the incorporation of DOM, most microbial populations such as heterotrophic bacteria will be preyed on by organisms at higher trophic levels such as grazers or zooplankton. However, about 20 to 40 percent of the bacterial biomass (with similar and relative amounts of eukaryotes) will become infected by viruses, due to the viral shunt.
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In July 2015, Nikolić released single "Voli me, voli me" (Love Me, Love Me). Its music video, directed by Dejan Milićević, received scrutiny for copying scenes from several other music videos by different global popstars such as Mariah Carey's "Heartbreaker", Beyoncé's "Partition" and Nicki Minaj's "Anaconda". In May 2016, she then released Labilna (Labile), which marked a significant departure from her previous work to a more urban sound. While working on her fifth album, Nikolić secretly started dating Serbian producer and recording artist Stefan Đurić Rasta, whom got married in July 2016.
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PDB: 1MDT Upon activation, bAREs ADP-ribosylate any number of eukaryotic proteins; such mechanism is crucial to the instigation of the diseased states associated with ADP-ribosylation. GTP-binding proteins, in particular, are well-established in bAREs pathophysiology. For examples, cholera and heat-labile enterotoxin target the α-subunit of Gs of heterotrimeric GTP-binding proteins. As the α-subunit is ADP-ribosylated, it is permanently in an "active", GTP-bound state; subsequent activation of intracellular cyclic AMP stimulates the release of fluid and ions from intestinal epithelial cells.
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This family is also known as Ct or Ctx, and also includes the heat-labile enterotoxin, known as LT. Cholera toxin's discovery is credited by many to Dr. Sambhu Nath De. He conducted his research in Calcutta (now Kolkata) making his discovery in 1959, although it was first purified by Robert Koch in 1883. Cholera toxin is composed of a protein complex that is secreted by the bacterium Vibrio cholerae. Some symptoms of this toxin include chronic and widespread watery diarrhea and dehydration that, in some cases, leads to death.
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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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Mood symptoms in individuals with FXS rarely meet diagnostic criteria for a major mood disorder as they are typically not of sustained duration. Instead, these are usually transient and related to stressors, and may involve labile (fluctuating) mood, irritability, self- injury and aggression. Individuals with fragile X-associated tremor/ataxia syndrome (FXTAS) are likely to experience combinations of dementia, mood, and anxiety disorders. Males with the FMR1 premutation and clinical evidence of FXTAS were found to have increased occurrence of somatization, obsessive–compulsive disorder, interpersonal sensitivity, depression, phobic anxiety, and psychoticism.
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However carry-over contamination can be controlled by the following two steps: (i) incorporating dUTP in all PCR products (by substituting dUTP for dTTP, or by incorporating uracil during synthesis of primers; and (ii) treating all subsequent fully preassembled starting reactions with uracil DNA glycosylase (UDG), followed by thermal inactivation of UDG. UDG cleaves the uracil base from the phosphodiester backbone of uracil-containing DNA, but has no effect on natural (i.e., thymine-containing) DNA. The resulting apyrimidinic sites block replication by DNA polymerases, and are very labile to acid/base hydrolysis.
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The frit FAB and continuous flow-FAB (CF- FAB) interfaces were developed in 1985 and 1986 respectively. Both interfaces were similar, but they differed in that the first used a porous frit probe as connecting channel, while CF-FAB used a probe tip. From these, the CF-FAB was more successful as a LC-MS interface and was useful to analyze non-volatile and thermally labile compounds. In these interfaces, the LC effluent passed through the frit or CF-FAB channels to form a uniform liquid film at the tip.
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Unfortunately, in this case it cannot be decided whether the transfer occurs between distant atoms or during a normal collision or even in a labile molecule formed as an intermediate. This decision, however, was possible in similar cases, as in the mercury-sensitized fluorescence of sodium and in the mutual sensitization of the fluorescence of different mercury isotopes. In these cases, the transfer occurs over distances very much larger than those in normal collisional separations. Similar observations of sensitized fluorescence were made with molecular vapours and in solution.
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But some of the (new) food processing technologies have downfalls as well. Modern separation techniques such as milling, centrifugation, and pressing have enabled concentration of particular components of food, yielding flour, oils, juices, and so on, and even separate fatty acids, amino acids, vitamins, and minerals. Inevitably, such large-scale concentration changes the nutritional content of food, saving certain nutrients while removing others. Heating techniques may also reduce food's content of many heat-labile nutrients such as certain vitamins and phytochemicals, and possibly other yet-to-be-discovered substances.
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The binding of C5 is influenced by C6 and C7, components which are thought to act subsequent to it in the complement sequence. In addition, the hemolytic activity of the isolated C5 intermediate complex is exceedingly labile, having an average half-life at 30 °C of only 9 rain. This characteristic distinguishes the C5 step, along with the C2 step, as potentially rate-limiting in the complement reaction. However, unlike C2, C5 remains firmly cell-bound during the decay process and apparently undergoes an alteration in situ which renders it hemolytically unreactive.
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In 1933 Russian psychiatrist Pyotr Borisovich Gannushkin published his book Manifestations of Psychopathies: Statics, Dynamics, Systematic Aspects, which was one of the first attempts to develop a detailed typology of psychopathies. Regarding maladaptation, ubiquity, and stability as the three main symptoms of behavioral pathology, he distinguished nine clusters of psychopaths: cycloids (including constitutionally depressive, constitutionally excitable, cyclothymics, and emotionally labile), asthenics (including psychasthenics), schizoids (including dreamers), paranoiacs (including fanatics), epileptoids, hysterical personalities (including pathological liars), unstable psychopaths, antisocial psychopaths, and constitutionally stupid.Ганнушкин П. Б. (2000). Клиника психопатий, их статика, динамика, систематика.
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Sato spent summer 1974 through spring 1975 on sabbatical working with Dr. Niels Kaj Jerne at the Basel Institute for Immunology in Basel, Switzerland. Sato was recruited as director of The W. Alton Jones Cell Science Center, Lake Placid, New York (1983 to 1992). His vision was to build a research university similar to Rockefeller University in the peaceful setting of the Adirondack Mountains of New York. Instead of the dependence on the labile support of individual government and private grants, the goal was to fund and endow the institute by proceeds from a for-profit biotechnology venture called Upstate Biotechnology, Inc.
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The vaccine tested in the phase II clinical trial in India did not proceed further because it produced antibody titers of 50 ng/mL for at least 3 months duration in only 60% of women in the trial. Ongoing research in hCG birth control vaccines has focused on improving immunogenicity. A vaccine in which the beta subunit of hCG is fused to the B subunit of Escherichia coli heat-labile enterotoxin has been effective in laboratory mice. It has been approved by the Indian National Review Committee on Genetic Manipulation and is being produced for pre-clinical toxicology testing.
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Enamines are labile and therefore chemically useful moieties which can be easily produced from commercially available starting reagents. A common route for enamine production is via an acid- catalyzed nucleophilic reaction of ketone (Stork, 1963) or aldehyde (Mannich/Davidsen, 1936) species containing an α-hydrogen with secondary amines. Acid catalysis is not always required, if the pKa of the reacting amine is sufficiently high (for example, pyrrolidine, which has a pKa of 11.26). If the pKa of the reacting amine is low, however, then acid catalysis is required through both the addition and the dehydration steps (common dehydrating agents include MgSO4 and Na2SO4).
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Since the mid-19th century the existence of true nascent hydrogen has repeatedly been challenged. It was assumed by the supporters of this theory that, before two hydrogen atoms can recombine into a more stable H2 molecule, the labile H· free radicals are more reactive than molecular H2, a relatively weak reductant in the absence of a metal catalyst. Nascent hydrogen was supposed to be responsible for the reduction of arsenate or nitrate in arsine or ammonia respectively. Nowadays, isotopic evidence has closed the nascent hydrogen debate, presently considered to be a Gedanken artifact of romanticism.
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GSNO and NO concentrations regulate respiratory function by modulating airway tone and pro- and anti-inflammatory responses in the respiratory tract. Because NO is a labile gas and endogenous levels are difficult to manipulate, it has been proposed that exogenous GSNO could be used to regulate circulating levels of NO and NO-derived species, and GSNO could have value in patients with pulmonary diseases such as cystic fibrosis. Consistent with this therapeutic goal, a recent study showed that acute treatment with aerosolized GSNO was well tolerated by cystic fibrosis patients. SNOs in the hepatic mitochondria appear to influence proper functioning of the liver.
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Extradiol members utilize ferrous iron as the active redox state, and this center is commonly coordinated octahedrally through a 2-His-1-Glu motif with labile water ligands occupying empty positions. Once a substrate binds to the ferrous center, this promotes dioxygen binding and subsequent activation. This activated oxygen species then proceeds to react with the substrate ultimately cleaving the carbon-carbon bond adjacent to the hydroxyl groups through the formation of an α-keto lactone intermediate. In the 2OG-dependent dioxygenases, ferrous iron (Fe(II)) is also coordinated by a (His)2(Glu/Asp)1 "facial triad" motif.
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Familial dysautonomia (FD) is a rare, progressive, recessive genetic disorder of the autonomic nervous system seen primarily in people of Eastern European Jewish descent that affects the development and survival of sensory, sympathetic and some parasympathetic neurons in the autonomic and sensory nervous system. FD results in variable symptoms, including insensitivity to pain, inability to produce tears, poor growth and labile blood pressure (episodic hypertension and postural hypotension). People with FD have frequent vomiting crises, pneumonia, problems with speech and movement, difficulty swallowing, inappropriate perception of heat, pain and taste as well as unstable blood pressure and gastrointestinal dysmotility. Originally reported by Drs.
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She was elected to go the House of Representatives for the LPF on 15 May 2002 but could not be sworn in as a member until 28 May because of a mental breakdown caused by the campaign and the death of Pim Fortuyn. This also caused her to miss the election for fractievoorzitter. Later Winny de Jong declared her labile behavior was caused by a bipolar disorder. De Volkskrant reported in an article about incivility in Dutch politics that Winny de Jong called her political adversaries "landverraders" (traitors to the country) and Els Borst "een fossiel" (a fossil).
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The choice of a specific nitroxide species to use has a large effect on the efficacy of an attempted polymerization. An effective polymerization (fast rate of chain growth, consistent chain length) results from a nitroxide with a fast C-O homolysis and relatively few side reactions. A more polar solvent lends itself better to C-O homolysis, so polar solvents which cannot bind to a labile nitroxide are the most effective for NMP. It is generally agreed that the structural factor that has the greatest effect on the ability of a nitroxide to mediate a radical polymerization is steric bulk.
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When the plasma ionized calcium rises above normal (hypercalcemia) more calcium is bound to these sodium channels having the opposite effect, causing lethargy, muscle weakness, anorexia, constipation and labile emotions. The tertiary structure of proteins is also affected by the pH of the bathing solution. In addition, the pH of the ECF affects the proportion of the total amount of calcium in the plasma which occurs in the free, or ionized form, as opposed to the fraction that is bound to protein and phosphate ions. A change in the pH of the ECF therefore alters the ionized calcium concentration of the ECF.
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"Befour" addresses both his past and his detractors at the same time, including his past as a working class teenager in Bradford (which the music video is based on), his former band, and the scrutiny of his detractors. "She" features a female protagonist that has not loved or been loved "in the right way". "Drunk" highlights the album's recurring theme of "emotionally labile intoxicated love", which is a common theme in Islamic poetry. The Urdu lyrics of "Flower" is romantic, it translates to "Until the flower of this love has blossomed, this heart won't be at peace, give me your heart".
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Most organoplatinum(0) compounds contain alkene and alkyne ligands. Carbonyl complexes are rare, and the analogue of Ni(CO)4 is elusive. The alkene and alkyne ligands serve as two-electron donors, for example in the complexes (PPh3)2Pt(C2H4) and (PPh3)2Pt(C2Ph2). The ethylene ligand in (PPh3)2Pt(C2H4) is labile and exchanges with alkynes and electrophilic alkenes, even C60 a fullerene. A general synthetic route to (PPh3)2Pt(un) (un = alkene, alkyne) is reduction of potassium tetrachloroplatinate with ethanolic potassium hydroxide or hydrazine in presence of a phosphine ligand such as triphenylphosphine and the alkene or alkyne.
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The DLD homodimer functions as the E3 component of the pyruvate, α-ketoglutarate, and branched-chain amino acid-dehydrogenase complexes and the glycine cleavage system, all in the mitochondrial matrix. In these complexes, DLD converts dihydrolipoic acid and NAD+ into lipoic acid and NADH. DLD also has diaphorase activity, being able to catalyze the oxidation of NADH to NAD+ by using different electron acceptors such as O2, labile ferric iron, nitric oxide, and ubiquinone. DLD is thought to have a pro-oxidant role by reducing oxygen to a superoxide or ferric to ferrous iron, which then catalyzes production of hydroxyl radicals.
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Since then, a variety of small proteins (up to 200 residues) have been synthesized, including ubiquitin and other similar modifier proteins, hormone proteins, nitrophorin 4, S100A4 and cyclic proteins. C-terminal ketoacid monomers are pre-loaded on resin via a linker for Fmoc-SPPS (Fmoc-based solid phase peptide synthesis). Initial research utilised sulfur ylide linkers, but more recently the group developed acid- and photo-labile ketoacid monomers that can be loaded directly on Rink Amide resin. The most commonly used N-terminal hydroxylamine is the 5-oxaproline, which results in a homoserine residue after ligation and O-N rearrangement.
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In these cases, the character itself is often downweighted so that small changes in allele frequencies count less than major changes in other characters. Also, the third codon position in a coding nucleotide sequence is particularly labile, and is sometimes downweighted, or given a weight of 0, on the assumption that it is more likely to exhibit homoplasy. In some cases, repeated analyses are run, with characters reweighted in inverse proportion to the degree of homoplasy discovered in the previous analysis (termed successive weighting); this is another technique that might be considered circular reasoning. Character state changes can also be weighted individually.
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To provide maximum benefit from each blood donation and to extend shelf-life, blood banks fractionate some whole blood into several products. The most common of these products are packed RBCs, plasma, platelets, cryoprecipitate, and fresh frozen plasma (FFP). FFP is quick-frozen to retain the labile clotting factors V and VIII, which are usually administered to patients who have a potentially fatal clotting problem caused by a condition such as advanced liver disease, overdose of anticoagulant, or disseminated intravascular coagulation (DIC). Units of packed red cells are made by removing as much of the plasma as possible from whole blood units.
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Electrostatic properties of cowpea chlorotic mottle virus The assembly of a virus is key to its efficacy as it needs to be both stable enough to protect its genome before entry into the cell and labile enough to release its genetic contents into target cell as it disassembles. The single stranded RNA is threaded through small pores already present in the capsid. At a neutral pH, the capsid protein reversibly binds to RNA forming a pre-capsid complex. This consists of RNA surrounded by enough capsid proteins (CP) to neutralize the negative charges of the RNA phosphate backbone.
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Cytokinesis in terrestrial plants occurs by cell plate formation. This process entails the delivery of Golgi-derived and endosomal vesicles carrying cell wall and cell membrane components to the plane of cell division and the subsequent fusion of these vesicles within this plate. After formation of an early tubulo-vesicular network at the center of the cell, the initially labile cell plate consolidates into a tubular network and eventually a fenestrated sheet. The cell plate grows outward from the center of the cell to the parental plasma membrane with which it will fuse, thus completing cell division.
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The cognate response regulator (RR) then catalyzes the transfer of the phosphoryl group to an aspartate residue on the response regulator's receiver domain. This typically triggers a conformational change that activates the RR's effector domain, which in turn produces the cellular response to the signal, usually by stimulating (or repressing) expression of target genes. Many HKs are bifunctional and possess phosphatase activity against their cognate response regulators, so that their signaling output reflects a balance between their kinase and phosphatase activities. Many response regulators also auto- dephosphorylate, and the relatively labile phosphoaspartate can also be hydrolyzed non-enzymatically.
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Through ancestral state reconstruction, scientists have shown that the evolution of viviparity to oviparity may have occurred a maximum of eight times in the genus Gerrhonotus of anguid lizards. Advanced ancestral state reconstruction was used to more accurately prove that the reverse evolution of viviparity to oviparity is true. In the analysis, the authors use a maximum likelihood tree to reveal that parity mode is a labile trait in the Squamata order. They also further show through analysis that viviparity is also strongly associated with cooler climates which suggests the previously stated "cold-climate hypothesis" is true.
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Although organic matter breakdown occurs rapidly in the presence of oxygen, microbes utilizing a variety of chemical species (via redox gradients) can degrade organic matter in anoxic sediments. The burial depth at which degradation halts depends upon the sedimentation rate, the relative abundance of organic matter in the sediment, the type of organic matter being buried, and innumerable other variables. While decomposition of organic matter can occur in anoxic sediments when bacteria use oxidants other than oxygen (nitrate, sulfate, Fe3+), decomposition tends to end short of complete mineralization. This occurs because of preferential decomposition of labile molecules over refractile molecules.
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Free radical damage to DNA can occur as a result of exposure to ionizing radiation or to radiomimetic compounds. Damage to DNA as a result of free radical attack is called indirect DNA damage because the radicals formed can diffuse throughout the body and affect other organs. Malignant melanoma can be caused by indirect DNA damage because it is found in parts of the body not exposed to sunlight. DNA is vulnerable to radical attack because of the very labile hydrogens that can be abstracted and the prevalence of double bonds in the DNA bases that radicals can easily add to.
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Dissolved organic matter (DOM) is available in many forms in the ocean, and is responsible for supporting the growth of bacteria and microorganisms in the ocean. The two main sources of this dissolved organic matter are; decomposition of higher trophic level organisms like plants and fish, and secondly DOM in runoffs that pass through soil with high levels of organic material. It is important to note that the age and quality of the DOM is important for its usability by microbes. The majority of the DOM in the oceans is refractory or semi-labile and is not available for biodegradation.
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Deuterium oxide is used in nuclear magnetic resonance spectroscopy when using water as solvent if the nuclide of interest is hydrogen. This is because the signal from light-water (1H2O) solvent molecules interferes with the signal from the molecule of interest dissolved in it. Deuterium has a different magnetic moment and therefore does not contribute to the 1H-NMR signal at the hydrogen-1 resonance frequency. For some experiments, it may be desirable to identify the labile hydrogens on a compound, that is hydrogens that can easily exchange away as H+ ions on some positions in a molecule.
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Dominant VOCs in one study were linalool oxide, trans-linalool oxide, 2-phenylacetaldehyde, benzyl ethanol, isophorone, and methyl nonanoate. VOCs can also be introduced from the bodies of the bees, be produced by the enzymatic actions of digestion, or from chemical reactions that occur between different substances within the honey during storage, and therefore may change, increase, or decrease over long periods of time. VOCs may be produced, altered, or greatly affected by temperature and processing. Some VOCs are heat labile, and are destroyed at elevated temperatures, while others can be created during non- enzymatic reactions, such as the Maillard reaction.
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The term is used to describe a transient chemical species. As a general example, if a molecule exists in a particular conformation for a short lifetime, before adopting a lower energy conformation (structural arrangement), the former molecular structure is said to have 'high lability' (such as C25, a 25-carbon fullerene spheroid). The term is sometimes also used in reference to reactivity – for example, a complex that quickly reaches equilibrium in solution is said to be labile (with respect to that solution). Another common example is the cis effect in organometallic chemistry, which is the labilization of CO ligands in the cis position of octahedral transition metal complexes.
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Thomas discovered that the UV absorption of native DNA is far lower than expected from a "theoretical" spectrum built from the extinction coefficients of its component nucleotides. This gap disappears after mild treatments such as lower or higher pH, higher temperature, or lower ionic strength, especially lower concentration of divalent cations. These preserve the inter-nucleotide bonds that maintain the DNA structure, implying that the nitrogenous bases, responsible for the UV absorbance, interact by weak bonds (Hydrogen bonds or Van de Waals forces), contributing a labile secondary structure to DNA. Melting this secondary structure was coined DNA denaturation, by analogy with the similar process long known for proteins.
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Many of these features make lanthanide complexes effective catalysts. Hard Lewis acids are able to polarise bonds upon coordination and thus alter the electrophilicity of compounds, with a classic example being the Luche reduction. The large size of the ions coupled with their labile ionic bonding allows even bulky coordinating species to bind and dissociate rapidly, resulting in very high turnover rates; thus excellent yields can often be achieved with loadings of only a few mol%. The lack of orbital interactions combined with the lanthanide contraction means that the lanthanides change in size across the series but that their chemistry remains much the same.
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Confirmatory studies from other groups led to their final approval several years later. Owren initially felt that factor V (labile factor or proaccelerin) activated another factor, which he named VI. VI was the factor that accelerated the conversion from prothrombin to thrombin. It was later discovered that factor V was "converted" (activated) by thrombin itself, and later still that factor VI was simply the activated form of factor V. The complete amino acid sequence of the protein was published in 1987. In 1994 factor V Leiden, resistant to inactivation by protein C, was described; this abnormality is the most common genetic cause for thrombosis.
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Once all of the oxygen is used up, bacteria are able to carry out an anoxic sequence of chemical reactions as an energy source, all with negative ∆G°r values, with the reaction becoming less favorable as the chain of reactions proceeds. The same principle described above explaining the preferential degradation of nitrogen-rich organic matter occurs within the sediments, as they are more labile and are in higher demand. This principle has been utilized in paleoceanographic studies in order to identify core sites that have not experienced much microbial activity, or contamination by terrestrial sources with much higher C/N ratios.Raymo, M. E., et al.
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Diamphotoxin, the poisonous compound in Diamphidia, is highly labile, and has a low molecular weight. It is bound to a protein that protects it from deactivation. It causes an increased permeability of cell membranes, which, while not affecting normal ionic flow between cells, allows easy access to all small ions, thereby fatally disrupting normal cellular ionic levels.TF Jacobsen, O Sand, T Bjøro, HE Karlsen, JG Iversen, Effect of Diamphidia toxin, a Bushman arrow poison, on ionic permeability in nucleated cells, Toxicon (1990) 28: 435-44 Although it has no neurotoxic effect, it produces a lethal haemolytic effect, and may reduce haemoglobin levels by as much as 75%, leading to haemoglobinuria.
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Li Ling was dispatched twice by the Chanyu to persuade the detained Han ambassador Su Wu to surrender, as Li and Su used to be co-workers and good friends. Initially Li Ling was too ashamed to visit Su Wu, as he defected merely the year after Su's exile to Lake Baikal. On his first visit, Li Ling mentioned how everyone in Su Wu's family back in China had either died or remarried, hoping to sever Su's patriotic bond. Li then said that Emperor Wu had grown old and emotionally labile, and how he himself used to suffer over the guilt of treason but had overcome that eventually.
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Mobility refers to the extent to which affect changes during the interview: the affect may be described as fixed, mobile, immobile, constricted/restricted or labile. The person may show a full range of affect, in other words a wide range of emotional expression during the assessment, or may be described as having restricted affect. The affect may also be described as reactive, in other words changing flexibly and appropriately with the flow of conversation, or as unreactive. A bland lack of concern for one's disability may be described as showing la belle indifférence,French: beautiful indifference a feature of conversion disorder, which is historically termed "hysteria" in older texts.
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DNA cleavage by bleomycin depends on oxygen and metal ions, at least in vitro. The exact mechanism of DNA strand scission is unresolved, but it has been suggested that bleomycin chelates metal ions (primarily iron), producing a pseudoenzyme that reacts with oxygen to produce superoxide and hydroxide free radicals that cleave DNA. An alternative hypothesis states that bleomycin may bind at specific sites in the DNA strand and induce scission by abstracting the hydrogen atom from the base, resulting in strand cleavage as the base undergoes a Criegee-type rearrangement, or forms an alkali-labile lesion. In addition, these complexes also mediate lipid peroxidation and oxidation of other cellular molecules.
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Supercritical fluid chromatography (SFC) can be used on an analytical scale, where it combines many of the advantages of high performance liquid chromatography (HPLC) and gas chromatography (GC). It can be used with non-volatile and thermally labile analytes (unlike GC) and can be used with the universal flame ionization detector (unlike HPLC), as well as producing narrower peaks due to rapid diffusion. In practice, the advantages offered by SFC have not been sufficient to displace the widely used HPLC and GC, except in a few cases such as chiral separations and analysis of high- molecular-weight hydrocarbons. For manufacturing, efficient preparative simulated moving bed units are available.
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Diamphotoxin, the toxic compound in Diamphidia, is highly labile, and has a low molecular weight. It is bound to a protein that protects it from deactivation. It causes an increased permeability of cell membranes, which, while not affecting normal ionic flow between cells, allows easy access to all small ions, thereby fatally disrupting normal cellular ionic levels.TF Jacobsen, O Sand, T Bjøro, HE Karlsen, JG Iversen, Effect of Diamphidia toxin, a Bushman arrow poison, on ionic permeability in nucleated cells, Toxicon (1990) 28: 435-44 Although it has no neurotoxic effect, it produces a lethal haemolytic effect, and may reduce haemoglobin levels by as much as 75%, leading to haemoglobinuria.
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Due to the oxidative properties of oxygen, most nitrogenases are irreversibly inhibited by dioxygen, which degradatively oxidizes the Fe-S cofactors. This requires mechanisms for nitrogen fixers to protect nitrogenase from oxygen in vivo. Despite this problem, many use oxygen as a terminal electron acceptor for respiration. Although the ability of some nitrogen fixers such as Azotobacteraceae to employ an oxygen-labile nitrogenase under aerobic conditions has been attributed to a high metabolic rate, allowing oxygen reduction at the cell membrane, the effectiveness of such a mechanism has been questioned at oxygen concentrations above 70 μM (ambient concentration is 230 μM O2), as well as during additional nutrient limitations.
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The voltage gated sodium ion channels in the cell membranes of nerves and muscle are particularly sensitive to the calcium ion concentration in the plasma. Relatively small decreases in the plasma ionized calcium levels (hypocalcemia) cause these channels to leak sodium into the nerve cells or axons, making them hyper- excitable (positive bathmotropic effect), thus causing spontaneous muscle spasms (tetany) and paraesthesia (the sensation of "pins and needles") of the extremities and round the mouth. When the plasma ionized calcium rises above normal (hypercalcemia) more calcium is bound to these sodium channels having a negative bathmotropic effect on them, causing lethargy, muscle weakness, anorexia, constipation and labile emotions.
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Because the phenomenon is labile, it has been used to show the effects of social influence or suggestion on judgements. For example, if an observer who would otherwise say the light is moving one foot overhears another observer say the light is moving one yard, then the first observer will report that the light moved one yard. Discovery of the influence of suggestion on the autokinetic effect is often attributed to Sherif (1935), but it was recorded by Adams (1912), if not others. Alexander von Humboldt observed the phenomenon in 1799 while looking at stars with the naked eye, but thought it was a real movement of the stars.
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Supercritical fluid chromatography (SFC) is a form of normal phase chromatography that uses a supercritical fluid such as carbon dioxide as the mobile phase. It is used for the analysis and purification of low to moderate molecular weight, thermally labile molecules and can also be used for the separation of chiral compounds. Principles are similar to those of high performance liquid chromatography (HPLC), however SFC typically utilizes carbon dioxide as the mobile phase; therefore the entire chromatographic flow path must be pressurized. Because the supercritical phase represents a state in which liquid and gas properties converge, supercritical fluid chromatography is sometimes called convergence chromatography.
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The synthesis of stibinin can be accomplished in a three step process. The final product can be isolated, even though the molecule is highly labile. The first step of this synthesis involves the treatment of penta-1,4-diyne with dibutylstannane as shown in the figure below. C5H4 + Bu2SnH2 -> C13H24Sn 383x383px The second step of the synthesis involves reacting the product of the first step, 1,1-dibutyl-1,4-dihydrostannine, with antimony trichloride, to yield 1-chloro-1-stibacyclohexa-2,5-diene. C13H24Sn + SbCl3 -> C5H6SbCl 441x441px The final step of the synthesis of stibinin involves treating 1-chloro-1-stibacyclohexa-2,5-diene with a base, such as 1,5-Diazabicyclo[4.3.
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In 1985, she gave up her official Fellowship and was appointed a bye-fellow because her blood pressure became labile, which meant she could no longer commit herself to continue teaching undergraduates on a regular basis. She continued teaching a large group of doctoral students, who called themselves 'The Spuffordians' and came to her from as far away as Canada, California, Australia and Japan because of her reputation, based on her publications. After a year at the Netherlands Institute for Advanced Study in Wassenaar, she was appointed Research Professor in Social and Local History at the University of Roehampton in 1994. She retired in 2001.
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In addition to the weakly coordinating nature of the anion, salts are often more soluble in organic solvents (lipophilic) than the related nitrate or halide salts. Related to are hexafluorophosphate, , and hexafluoroantimonate, , both of which are even more stable toward hydrolysis and other chemical reactions and whose salts tend to be more lipophilic. Illustrative of a fluoroborate salt is [Ni(CH3CH2OH)6](BF4)2, a kinetically labile octahedral complex, which is used as a source of Ni2+. Extremely reactive cations such as those derived from Ti, Zr, Hf, and Si do in fact abstract fluoride from , so in such cases is not an "innocent" anion and less coordinating anions (e.g.
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Part of the exceptional reactivity of compounds of hyper leaving groups has been ascribed to the entropic favorability of having one molecule split into three. The ability of hyper leaving groups is enhanced by entropic factors Dialkyl halonium ions have also been isolated and characterized for simple alkyl groups. These compounds, despite their extreme reactivity towards nucleophiles, can be obtained pure in the solid state with very weakly nucleophilic counterions such as SbF and CHB11Cl11−. The strongly electrophilic nature of these compounds engendered by their attachment to extremely labile R-X (R = alkyl, X = Cl, Br, I) leaving groups is illustrated by their propensity to alkylate very weak nucleophiles.
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For analysis of RNA, samples should be cryogenically frozen (−196 °C) almost immediately upon collection, or stored in an RNA stabilization and preservation reagent (e.g. RNAlater). The next step is to extract the desired nucleic acids from the sample, which can be performed manually using various published extraction methods or by using one of the many commercially available DNA/RNA extraction kits. Due to the labile nature of RNA, synthesis of complementary DNA (cDNA) using extracted RNA as a template is performed for further analysis. For most molecular genetic sequencing methods of AM fungi a PCR step is required to increase the total amount of target DNA/RNA/cDNA.
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In people with bipolar disorder, decreased vPFC activity allows for dysregulated activity of the amygdala, which likely contributes to labile mood and poor emotional regulation. Consistent with this, pharmacological treatment of mania returns vPFC activity to the levels in non-manic people, suggesting that vPFC activity is an indicator of mood state. However, while pharmacological treatment of mania reduces amygdala hyperactivity, it remains more active than the amygdala of those without bipolar disorder, suggesting amygdala activity may be a marker of the disorder rather than the current mood state. Manic and depressive episodes tend to be characterized by dysfunction in different regions of the vPFC.
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Alleyways are an urban form historically shared by most cities in Asia, yet understudied. Alleyways in Asia can be understood as ordinary neighbourhood landscape providing the setting for everyday urban life and place-based identities being shaped by varied everyday practices, collective experiences and forces. This turns the traditional approach of "global cities" upside-down and contributes to a renewed conception of metropolization as a highly situated process, where forces at play locally, in each alleyway neighbourhood, are both intertwined and labile. Thus it is important to study the modern transformation of Asian cities and their urban cultures, from the perspective of the alleyways, including new approaches to social life, urban change and urban governance.
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Several molecular isoforms of GH exist in the pituitary gland and are released to blood. In particular, a variant of approximately 20 kDa originated by an alternative splicing is present in a rather constant 1:9 ratio, while recently an additional variant of ~ 23-24 kDa has also been reported in post-exercise states at higher proportions. This variant has not been identified, but it has been suggested to coincide with a 22 kDa glycosylated variant of 23 kDa identified in the pituitary gland. Furthermore, these variants circulate partially bound to a protein (growth hormone-binding protein, GHBP), which is the truncated part of the growth hormone receptor, and an acid-labile subunit (ALS).
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The preparation of this perfusate had been laborious and time-consuming, and there was the potential risk from hepatitis virus and cytotoxic antibodies. The absence of lipo-proteins from the perfusate meant that the membrane oxygenator could be eliminated from the perfusion circuit, as there was no need to avoid a perfusate/air interface to prevent precipitation of lipo-proteins. Both workers used the same additives as recommended by Belzer. The solution that Johnson used was prepared by the Blood Products Laboratory (Elstree: England) by extracting heat labile fibrinogen and gamma globulins from plasma to give a plasma protein fraction (PPF) solution. The solution was incubated at 60 °C for 10 hours to inactivate the agent of serum hepatitis.
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The efficiency of polymerization increases more and more with increased steric bulk of the nitroxide up to a point. TEMPO ((2,2,6,6-Tetramethylpiperidin-1-yl)oxyl) is capable of inducing the polymerization of styrene and styrene derivatives fairly easily, but is not sufficiently labile to induce polymerization of butyl acrylate under most conditions. TEMPO derivatives with even bulkier groups at the positions α to N have a rate of homolysis great enough to induce NMP of butyl acrylate, and the bulkier the α groups, the faster polymerization occurs. This indicates that the steric bulk of the nitroxide fragment can be a good indicator of the strength of an alkoxyamine initiator, at least up to a point.
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Tyrrell immediately invited Hoorn to visit CCU, and after which they were was able to grow different viruses which could not be cultured earlier. Specimen B814 could the be confirmed as a virus, but was unique from all known cold viruses based on its antigenic property and symptoms it produced. Tyrrell and Malcolm L. Bynoe reported the discovery in the 5 June 1965 issue of the British Medical Journal, concluding: "After considerable initial doubts we now believe that the B814 strain is a virus virtually unrelated to any other known virus of the human respiratory tract, although, since it is ether-labile, it may be a myxovirus." This was the discovery of human coronavirus.
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As described above, the use of N-terminal and side chain protecting groups is essential during peptide synthesis to avoid undesirable side reactions, such as self-coupling of the activated amino acid leading to (polymerization). This would compete with the intended peptide coupling reaction, resulting in low yield or even complete failure to synthesize the desired peptide. Two principle orthogonal protecting group schemes exist for use in solid-phase peptide synthesis: so-called Boc/Bzl and Fmoc/tBu approaches. The Boc/Bzl strategy utilizes TFA-labile N-terminal Boc protection alongside side chain protection that is removed using anhydrous hydrogen fluoride during the final cleavage step (with simultaneous cleavage of the peptide from the solid support).
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Vaccines (and adjuvants) are inherently unstable during temperature changes, requiring cold chain management throughout the entire supply chain, typically at temperatures of . Because COVID-19 vaccine technologies are varied among several novel technologies, there are new challenges for cold chain management, with some vaccines that are stable while frozen but labile to heat, while others should not be frozen at all, and some are stable across temperatures. Freezing damage and inadequate training of personnel in the local vaccination process are major concerns. If more than one COVID-19 vaccine is approved, the vaccine cold chain may have to accommodate all these temperature sensitivities across different countries with variable climate conditions and local resources for temperature maintenance.
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Photoredox-catalyzed oxy- and aminotrifluoromethylation Hydrotrifluoromethylation of styrenes and aliphatic alkenes can be effected with a mesityl acridinium organic photoredox catalyst and Langlois' reagent as the source of CF3 radical. In this reaction, it was found that trifluoroethanol and substoichiometric amounts of an aromatic thiol, such as methyl thiosalicylate, employed in tandem served as the best source of hydrogen radical to complete the catalytic cycle. Diagram of two reagents for olefin hydrotrifluoromethylation Intramolecular hydroetherifications and hydroaminations proceed with anti-Markovnikov selectivity. One mechanism invokes the single-electron oxidation of the olefin, trapping the radical cation by a pendant hydroxyl or amine functional group, and quenching the resulting alkyl radical by H-atom transfer from a highly labile donor species.
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A large number of MPTs is often seen as an analytical failure, and is widely believed to be related to the number of missing entries ("?") in the dataset, characters showing too much homoplasy, or the presence of topologically labile "wildcard" taxa (which may have many missing entries). Numerous methods have been proposed to reduce the number of MPTs, including removing characters or taxa with large amounts of missing data before analysis, removing or downweighting highly homoplastic characters (successive weighting) or removing wildcard taxa (the phylogenetic trunk method) a posteriori and then reanalyzing the data. Numerous theoretical and simulation studies have demonstrated that highly homoplastic characters, characters and taxa with abundant missing data, and "wildcard" taxa contribute to the analysis.
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Migration in birds is highly labile and is believed to have developed independently in many avian lineages. While it is agreed that the behavioral and physiological adaptations necessary for migration are under genetic control, some authors have argued that no genetic change is necessary for migratory behavior to develop in a sedentary species because the genetic framework for migratory behavior exists in nearly all avian lineages. This explains the rapid appearance of migratory behavior after the most recent glacial maximum. Theoretical analyses show that detours that increase flight distance by up to 20% will often be adaptive on aerodynamic grounds – a bird that loads itself with food to cross a long barrier flies less efficiently.
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The TET enzymes each harbor a core catalytic domain with a double-stranded β-helix fold that contains the crucial metal-binding residues found in the family of Fe(II)/α-KG- dependent oxygenases. α-KG coordinates as a bidentate ligand (connected at two points) to Fe(II) (see Figure), while the 5mC is held by a noncovalent force in close proximity. The TET active site contains a highly conserved triad motif, in which the catalytically-essential Fe(II) is held by two histidine residues and one aspartic acid residue (see Figure). The triad binds to one face of the Fe center, leaving three labile sites available for binding α-KG and O2 (see Figure).
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Here blood sugar regulation is unable to function because the beta cells of the pancreatic islets are destroyed and cannot produce the necessary insulin. The blood sugar rises in a condition known as hyperglycemia. The plasma ionized calcium homeostat can be disrupted by the constant, unchanging, over-production of parathyroid hormone by a parathyroid adenoma resulting in the typically features of hyperparathyroidism, namely high plasma ionized Ca2+ levels and the resorption of bone, which can lead to spontaneous fractures. The abnormally high plasma ionized calcium concentrations cause conformational changes in many cell-surface proteins (especially ion channels and hormone or neurotransmitter receptors) giving rise to lethargy, muscle weakness, anorexia, constipation and labile emotions.
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Plant cell showing primary and secondary wall by CarolineDahl Most of the extracellular enzymes involved in polymer degradation in leaf litter and soil have been ascribed to fungi. By adapting their metabolism to the availability of varying amounts of carbon and nitrogen in the environment, fungi produce a mixture of oxidative and hydrolytic enzymes to efficiently break down lignocelluloses like wood. During plant litter degradation, cellulose and other labile substrates are degraded first followed by lignin depolymerization with increased oxidative enzyme activity and shifts in microbial community composition. In plant cell walls, cellulose and hemicellulose is embedded in a pectin scaffold that requires pectin degrading enzymes, such as polygalacturonases and pectin lyases to weaken the plant cell wall and uncover hemicellulose and cellulose to further enzymatic degradation.
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Much of the humus in most soils has persisted for more than 100 years, rather than having been decomposed into CO2, and can be regarded as stable; this organic matter has been protected from decomposition by microbial or enzyme action because it is hidden (occluded) inside small aggregates of soil particles, or tightly sorbed or complexed to clays. Most humus that is not protected in this way is decomposed within 10 years and can be regarded as less stable or more labile. Stable humus contributes few plant-available nutrients in soil, but it helps maintain its physical structure. A very stable form of humus is formed from the slow oxidation of soil carbon after the incorporation of finely powdered charcoal into the topsoil.
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Kaolinite (rich in Al/Si, low in Mg) is the first phyllosilicate to form, once the rock is metamorphosed to the oil window, and thus replicates the most labile regions of the fossil. Once the rock is heated and compressed further, to the gas window, illite (rich in K/Al) and chlorite (rich in Fe/Mg) start to form; once all the available K is used up, no further illite forms, so the last tissues to mature are replicated exclusively in chlorite. The precise mineral formation depends on the porewater (and thus rock) chemistry; the thickness of the films increases as metamorphism continues; and the minerals align with the prevailing strain. They are not present in comparable deposits with very little metamorphism.
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Alternative-complement-pathway C3/C5 convertase (, complement component C3/C5 convertase (alternative), proenzyme factor B, properdin factor B, C3 proactivator, glycine-rich beta-glycoprotein, heat-labile factor, C3 convertase, C3b,Bb,CVF,Bb,C5 convertase, (C3b)n,Bb, complement C 3(C 5) convertase (amplification), alternative complement pathway C3(C5) convertase, C5 convertase, CVF,Bb, (CVF)-dependent glycine-rich-beta-glucoprotein, cobra venom factor-dependent C3 convertase) is an enzyme. This enzyme catalyses the following chemical reaction : Cleavage of Arg-Ser bond in complement component C3 alpha-chain to yield C3a and C3b, and Arg- bond in complement component C5 alpha-chain to yield C5a and C5b This enzyme is a bimolecular complex of complement fragment Bb with either C3b or cobra venom factor.
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Neocarzinostatin (NCS) is a macromolecular chromoprotein enediyne antitumor antibiotic secreted by Streptomyces macromomyceticus. It consists of two parts, a labile chromophore (the non-protein molecular entity shown at right) and a 113 amino acid protein to which the chromophore is tightly and non- covalently bound with high affinity (Kd ~ 10−10 M). The non-protein component is a very potent DNA-damaging agent; However it is extremely unstable and the role of the protein is to protect it and release it to the target DNA. Opening of the epoxide under reductive conditions present in cells creates favorable conditions for a Bergman cyclization, leading to formation of benzyne, followed by DNA strand cleavage. Another important member of the chromoprotein group of natural products is kedarcidin.
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This relationship is further supported by the fact that mice lacking NMNAT2, which are normally not viable, are completely rescued by SARM1 deletion, placing NMNAT2 activity upstream of SARM1. Other pro-degeneration signaling pathways, such as the MAP kinase pathway, have been linked to SARM1 activation. MAPK signaling has been shown to promote the loss of NMNAT2, thereby promoting SARM1 activation, although SARM1 activation also triggers the MAP kinase cascade, indicating some form of feedback loop exists. One explanation for the protective effect of the WldS mutation is that the NMNAT1 region, which is normally localized to the soma, substitutes for the labile survival factor NMNAT2 to prevent SARM1 activation when the N-terminal Ube4 region of the WldS protein localizes it to the axon.
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Paul Labile Pogba (; born 15 March 1993) is a French professional footballer who plays for club Manchester United and the France national team. He operates primarily as a central midfielder, but can also be deployed as an attacking midfielder, defensive midfielder and deep-lying playmaker. Born in Lagny-sur- Marne, Pogba joined the youth team of Ligue 1 side Le Havre in 2007, before a protracted transfer brought him to Manchester United two years later. After beginning his senior career with Manchester United two years later, limited appearances persuaded him to depart to join Italian side Juventus on a free transfer in 2012, where he helped the club to four consecutive Serie A titles, as well as two Coppa Italia and two Supercoppa Italiana titles.
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Catalytic cycle for the anthraquinone process to produce hydrogen peroxide Today, hydrogen peroxide is manufactured almost exclusively by the anthraquinone process, which was formalized in 1936 and patented in 1939. It begins with the reduction of an anthraquinone (such as 2-ethylanthraquinone or the 2-amyl derivative) to the corresponding anthrahydroquinone, typically by hydrogenation on a palladium catalyst. In the presence of oxygen, the anthrahydroquinone then undergoes autoxidation: the labile hydrogen atoms of the hydroxy groups transfer to the oxygen molecule, to give hydrogen peroxide and regenerating the anthraquinone. Most commercial processes achieve oxidation by bubbling compressed air through a solution of the anthrahydroquinone, with the hydrogen peroxide then extracted from the solution and the anthraquinone recycled back for successive cycles of hydrogenation and oxidation.
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In the latter case, it is essentially the compounds containing the XW9 brick that have attracted his attention.J.Martin-Frère, Y.Jeannin, « Synthesis and X-ray structure of the first mercury(I) containing polytungstate [(Hg2)2WO(H2O)(AsW9O33)2]10- », Inorg.Chem., 23, (1984), p. 3304M.Alizadeh, S.Harlmaker, Y.Jeannin, J.Martin-Frère, M.Pope, « A heteropolyanion with fivefold molecular symmetry that contains a non labile encapsulated sodium ion. The structure and chemistry of [NaP5W30O110]14- », J.Am.Chem.Soc., 107, (1985), p. 2662Y.Jeannin, « Un nouveau polytungstate [As4W20O72(H2O)2]12- formé par la réunion de deux unités α-B-AsW9O33 par deux ponts originaux O2AsIIIOWO4(H2O) », C.R.Acad.Sc., série IIc, 161 (1999) The laboratory has made a major contribution to the development of their synthesis and structural study by X-ray and NMR of tungsten, holding the record for the largest known polytungstate.
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Notably, this is one of few examples of a diastereoselective intermolecular reductive Heck. In 2018, Engle and coworkers disclosed an intermolecular reductive Heck reaction of diverse terminal alkenes and select internal alkenes utilizing aqueous tetramethylammonium formate as the reductant. This method tolerated an array of functional groups, including reductively labile groups, on both the (hetero)aryl iodide and alkene coupling partners, and was generally regioselective for the anti-Markovnikov product for terminal alkenes. A variety of terminal alkenes were compatible with the conditions, including simple a-olefins, heteroatom-substituted alkenes, and alkene- containing complex molecules such as quinine (49) and various terpenes. In addition, cyclic internal alkenes (45 and 48) were suitable substrates, affording reasonable yields of product; however acyclic internal alkenes were poor substrates for the reaction in terms of yield and regioselectivity.
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Fmoc carbamate is frequently used as a protecting group for amines, where the Fmoc group can be introduced by reacting the amine with fluorenylmethyloxycarbonyl chloride (Fmoc-Cl), e.g.: :Scheme showing addition of an Fmoc group to an amino acid The other common method for introducing the Fmoc group is through 9-fluorenylmethylsuccinimidyl carbonate (Fmoc-OSu), which may itself be obtained by the reaction of Fmoc-Cl with the dicyclohexylammonium salt of N-hydroxysuccinimide. It may be cleaved by bases, typically a solution of piperidine: :Mechanism of the deprotection of the Fmoc group with piperidine Fmoc protection has found significant use in solid phase peptide synthesis because its removal with piperidine solution does not disturb the acid labile linker between the peptide and the resin.J. Jones, Amino Acid and Peptide Synthesis, 2nd edn.
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MR. Carter (Ed.) Canadian Society of Soil Science, Lewis Publishers, Ann Arbor, MI. As increasing dissolved organic carbon concentration increases absorbance in the UV range, the UV light has to be normalized to the concentration of dissolved organic carbon in mg per L to ascertain differences in the aromatic quality of the water. Aromatic character is used in the study of dissolved organic matter, from mineral soils, or organic soils, to use as an assay to whether or not dissolved organic carbon in the water is labile, a ready source of energy, or is from a relatively old source of carbon (recalcitrant). However, although a good indicator of aromaticity, caution must be used with determination of reactivity. Measures of water purity often rely on measuring turbidity, not aromaticity.
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R-4066 (Spirodone) is a drug which is an analogue of the opioid analgesic methadone, or more accurately norpipanone, where the metabolically labile dimethylamino group has been replaced by a piperidinospiro group. Developed by Janssen Pharmaceutica, it is around 212x more potent than methadone as an analgesic in animal tests, with an effective oral dosage of 0.07 mg/kg, but is shorter acting, with a duration of action of around 3 hours. If the ketone function is reduced and acetylated, the racemate 106 x methadone and has an analgesic duration of 20.5 hours compared to 8 hours for methadone. R-4066 has never been used in humans, but would be expected to produce effects similar to those of other potent opioid agonists, including strong analgesia, sedation, euphoria, constipation, itching and respiratory depression which could be harmful or fatal.
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The rise of online websites and hookup apps in the 1990s gave men new ways of cruising and meeting sexual partners, including the ability to arrange private sexual gatherings in their homes. From the early 2000s, historic venues of gay socialization such as bars, clubs, and dance events reduced in number in response to a range of factors, including gentrification, zoning laws, licensing restrictions, and the increased number of closeted or under the influence sexually labile men, and the increasing popularity of digital technologies for sexual and social purposes. In this context, PNP emerged as an alternative form of sexualized partying that enabled participants to avoid the public scrutiny and potentially judgmental and anxiety provoking nature of the "public space". Newly popular drugs such as methamphetamine and GHB/GBL replaced dance drugs such as ecstasy within this context.
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It has been demonstrated in an associative fear conditioning chain, such as CS2 \--> CS1 \--> US, that extinction of freezing responses to the first-order stimulus (CS1) leads to responding impairments in CS2, but extinction of the second-order stimulus (CS2), does not have any effect on CS1 (Debiec et al.). In the same study, the effect of activation (memory retrieval) on such an associative chain has been examined. Results demonstrated that protein synthesis inhibition after exposure to a single CS1 impairs responses to both CS1 and CS2, but protein synthesis inhibition after exposure to a single CS2, only disrupts CS2 and leaves CS1 freezing intact. Therefore, it is believed that when the first- order association is directly activated, it is placed into a labile state (as we would expect from reconsolidation research) which may affect dependent associations.
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The main base of the Japanese expedition is on Genji, where researchers establish good relations with the Ihrdizu civilization; machine translation between the languages is not perfect but sufficient for simple communication. As the sociology and history of the Ihrdizu are slowly uncovered, it is revealed that not all is as it seems; the race must have gone through many cycles of technological rise and fall; the invention of metallurgy and advance to the equivalent of an early industrial revolution must have occurred at least six or seven times. However, the Ihrdizu are completely unaware of this history. Life itself is at least as old as on Earth but more variegated; instead of ultraviolet radiation and impact events the more labile nature of the biomolecules (which contain several amino acids unknown on Earth) has acted as the driver of early evolution.
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This has been achieved in a general, efficient, and environmentally benign solution-phase synthesis of 2,5-diketopiperazines using microwave-assisted heating in water, which in contrast to other published methods is independent of the amino acid sequence, and no epimerization was seen.Amide bond formation of 2,5-DKPs via dipeptide cyclization from peptide synthesis and Ugi reaction The Ugi reaction using an isonitrile, amino acid, aldehyde and amine, can produce a dipeptide in equally high yield and optical purity, to that formed by standard peptide couplings. Commonly, an isonitrile is chosen to give a labile terminal amide to enable cyclization. For example, the direct 2,5-DKP ring formation via such an activated leaving group using the stable, easily accessible and versatile convertible isonitrile 1-isocyano-2-(2,2-dimethoxyethyl)-benzene 4 gave a one- pot synthesis of N-substituted 2,5-diketopiperazine's 7.
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Food poisoning in humans is caused by type A strains able to produce the CPE (for Clostridium perfringens enterotoxin). The CPE is a polypeptide of 35.5 kDa that accumulates in the beginning of the sporulation and is excreted to the media when it lysates at the end of the sporulation. It is coded by the cpe gene, present in less than the 5% of the type A strains, and it can be located in the chromosome or in an external plasmid In the United Kingdom and United States, C. perfringens bacteria are the third-most common cause of foodborne illness, with poorly prepared meat and poultry, or food properly prepared, but left to stand too long, the main culprits in harboring the bacterium. The C. perfringens enterotoxin (CPE) mediating the disease is heat-labile (inactivated at ).
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A special, reversal form of drug delivery where modulation of active migratory behaviour of the target cells is used to achieve targeted effects. The general components of the conjugates are designed as follows: (i) carrier – regularly possessing promoter effect also on internalization into the cell; (ii) chemotactically active ligands acting on the target cells; (iii) drug to be delivered in a selective way and (iv) spacer sequence which joins drug molecule to the carrier and due to it enzyme labile moiety makes possible the intracellular compartment specific release of the drug. Chemotactic drug-targeting Careful selection of chemotactic component of the ligand not only the chemoattractant character could be expended, however, chemorepellent ligands are also valuable as they are useful to keep away cell populations degrading the conjugate containing the drug. This mechanism of drug delivery is currently being studied.
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Proponents of magnetic beads claim that the beads exhibit a faster rate of protein binding over agarose beads for immunoprecipitation applications, although standard agarose bead-based immunoprecipitations have been performed in 1 hour. Claims have also been made that magnetic beads are better for immunoprecipitating extremely large protein complexes because of the complete lack of an upper size limit for such complexes, although there is no unbiased evidence stating this claim. The nature of magnetic bead technology does result in less sample handling due to the reduced physical stress on samples of magnetic separation versus repeated centrifugation when using agarose, which may contribute greatly to increasing the yield of labile (fragile) protein complexes. Additional factors, though, such as the binding capacity, cost of the reagent, the requirement of extra equipment and the capability to automate IP processes should be considered in the selection of an immunoprecipitation support.
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This study demonstrated the CuAAC mediated conjugation of 4RepCT^{3Aha} with two different fluorophores and the antibiotic levofloxacin, showcasing the potential of covalently functionalized recombinant spider silk proteins as biomaterials with enhanced properties. The researchers were able to successfully conjugate 4RepCT^{3Aha} with alkyne fluorophores, proving the protein can be functionalized through an azide group while conjugated to the axis of the silk fiber. Their results showed not only an intense uniform fluorescence along the fiber axis but also an intense uniform composite fluorescence when the fiber was decorated with two different fluorophores in a 1:1 ratio. To prove the functional azide group could be decorated with a clinically relevant molecule, the researchers attempted to decorate the fiber with glycidyl propargyl ether (and acid-labile linker) and bound Levofloxacin (a gram-positive targeting antibiotic) to it using an ester bond between the epoxide carboxylate groups respectively.
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Serological tests (antigen-antibody reactions) further indicated that the virus was not related (not reactive) to antibodies (serotypes) of any known viruses at the time. Reporting in the British Medical Journal, Tyrrell and Malcolm L. Bynoe wrote their conclusion as: > After considerable initial doubts we now believe that the B814 strain is a > virus virtually unrelated to any other known virus of the human respiratory > tract, although, since it is ether-labile, it may be a myxovirus. But they contradicted themselves regarding the identity of the virus as they mentioned in the experimental results, saying: > It was concluded that B814 did not belong to any of the serotypes of > myxovirus used, but might be distantly related to influenza C or Sendai > viruses. In an independent research in US, Dorothy Hamre and John J. Procknow studied respiratory tract infection among medical students at the University of Chicago.
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C60 forms complexes akin to the more common alkenes. Complexes have been reported molybdenum, tungsten, platinum, palladium, iridium, and titanium. The pentacarbonyl species are produced by photochemical reactions. : M(CO)6 \+ C60 → M(η2-C60)(CO)5 \+ CO (M = Mo, W) In the case of platinum complex, the labile ethylene ligand is the leaving group in a thermal reaction: : Pt(η2-C2H4)(PPh3)2 \+ C60 → Pt(η2-C60)(PPh3)2 \+ C2H4 Titanocene complexes have also been reported: : (η5-Cp)2Ti(η2-(CH3)3SiC≡CSi(CH3)3) + C60 → (η5-Cp)2Ti(η2-C60) + (CH3)3SiC≡CSi(CH3)3 Coordinatively unsaturated precursors, such as Vaska's complex, for adducts with C60: : trans-Ir(CO)Cl(PPh3)2 \+ C60 → Ir(CO)Cl(η2-C60)(PPh3)2 One such iridium complex, [Ir(η2-C60)(CO)Cl(Ph2CH2C6H4OCH2Ph)2] has been prepared where the metal center projects two electron-rich 'arms' that embrace the C60 guest.
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The genetic context of a typical type II toxin-antitoxin locus, produced during a bioinformatics analysis Type II toxin-antitoxin systems are generally better-understood than type I. In this system a labile proteic antitoxin tightly binds and inhibits the activity of a stable toxin. The largest family of type II toxin-antitoxin systems is vapBC, which has been found through bioinformatics searches to represent between 37 and 42% of all predicted type II loci.Type II systems are organised in operons with the antitoxin protein typically being located upstream of the toxin, which helps to prevent expression of the toxin without the antitoxin. The proteins are typically around 100 amino acids in length, and exhibit toxicity in a number of ways: CcdB, for example, affects DNA replication by poisoning DNA gyrase whereas the MazF and RelE toxins are endoribonuclease that cleaves cellular mRNAs at specific sequence motifs.
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The organosilane is activated with fluoride (as some sort of salt such as TBAF or TASF) or a base to form a pentavalent silicon center which is labile enough to allow for the breaking of a C-Si bond during the transmetalation step. The general scheme to form this key intermediate is shown below. This step occurs in-situ or at the same time as the catalytic cycle in the reaction. center The mechanism for the Hiyama coupling follows a catalytic cycle, including an A) oxidative addition step, in which the organic halide adds to the palladium oxidizing the metal from palladium(0) to palladium(II); a B) transmetalation step, in which the C-Si bond is broken and the second carbon fragment is bound to the palladium center; and finally C) a reductive elimination step, in which the C-C bond is formed and the palladium returns to its zero-valent state to start the cycle over again.
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Mecasermin () (brand name Increlex), also known as recombinant human insulin- like growth factor-1 (rhIGF-1), is a recombinant form of human insulin-like growth factor 1 (IGF-I) which is used in the long-term treatment of growth failure and short stature in children with severe primary IGF-I deficiency, for instance due to growth hormone deficiency or Laron syndrome (growth hormone insensitivity). Mecasermin has a biological half-life of about 5.8 hours in children with severe primary IGF-1 deficiency. A related medication is mecasermin rinfabate (brand name Iplex), which is a combination of mecasermin (rhIGF-1), insulin-like growth factor binding protein-3 (IGFBP-3), and insulin-like growth factor binding protein acid labile subunit (IGFALS) as a ternary complex. The complex serves to prolong the action of mecasermin in the human body; the half-life of mecasermin when provided as this complex is 13.4 hours in individuals with severe primary IGF-1 deficiency.
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The major contributions made by Chakraborty in the field of Environmental Geochemistry (particularly in the field of trace and toxic metal speciation in marine systems) are described below: Since the marine systems are dynamic in nature and never at chemical equilibrium, He realized that chemical-equilibrium-based approach to do metal speciation would give wrong estimates of labile metal concentrations (which are widely correlated with ecotoxicity) in marine sediments. He improved kinetics-based approaches to understand metals speciation and their bioavailability in estuarine/coastal and deep sea systems. His research focuses on developing and applying a wide range of kinetic methods for chemical speciation in marine/estuarine sediment systems, each with its own characteristic timescale of measurement. An important achievement of his research is to advance the science of metal speciation by identifying the analytical timescale of measurement as the critical parameter for defining the chemical species in coastal and marine sediment system.
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Since moving to Trondheim in 1977, Naqvi has worked on a wide range of problems within physics, chemistry and biology, dividing his time equally between theory and experiment and between the pure and the applied. These topics include: (1) calculation of Franck–Condon factors, (2) applications of linear transport theory to chemical kinetics, diffuse reflection spectroscopy, and phonon transport in semiconductors, (3) spectroscopy of absorbing and scattering specimens, (4) primary photophysical processes in carotenoids, vitamin E and related molecules, (5) revival of quantum wave packets, (6) photoprotection in artificial and natural photosynthesis, (7) use of diffusive gradient in thin films (DGTF) for the in situ measurement of the labile forms of chemical elements in aqueous environments, sediments and soils, and (8) non-invasive measurement of blood pressure. Naqvi’s many coauthors include a very large number of scientists from all over the world. Within NTNU, his collaborators include, apart from many physicists, several chemists (analytical, organic, physical) and two mathematicians.
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Ammonia adds to hexafluoroacetone to give a stable hemiaminal, (CF3)2C(OH)NH2.. Those generated from primary amines and ammonia are usually unstable to the extent that they have never been isolated and very rarely been observed directly. A hemiaminal trapped in the cavity of a host–guest complex exhibited chemical half-life of 30 minutes. Because both amine and carbonyl group are isolated in a cavity, hemiaminal formation is favored due to a high forward reaction rate comparable to an intramolecular reaction and also due to restricted access of external base (another amine) to the same cavity which would favor elimination of water to the imine.Stabilization of Labile Carbonyl Addition Intermediates by a Synthetic Receptor Tetsuo Iwasawa, Richard J. Hooley, Julius Rebek Jr. Science 317, 493 (2007) Hemiaminal formation is a key step in an asymmetric total synthesis of saxitoxin:(+)-Saxitoxin: A First and Second Generation Stereoselective Synthesis James J. Fleming, Matthew D. McReynolds, and J. Du Bois J. Am. Chem. Soc.
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While non- titanosaur phylogeny remained identical in every single result, the topology within Titanosauria was very labile and prone to change with minor adjustments. Mounted skeleton of Futalognkosaurus dukei Also following the 2002 analysis of Wilson, José Carballido and colleagues published a redescription of Chubutisaurus in 2011, and utilized an updated Wilson matrix, expanded to 289 characters across 41 taxa, including 15 titanosaurs. The primary focus of the analysis was on the basal titanosauriform taxa, but Titanosauria was defined, as the most recent common ancestor of Andesaurus delgadoi and Saltasaurus loricatus, and all its descendants, although the only autapomorphy of the group recovered was the absence of a prominent ventral process on the scapula. This same matrix and basis of characters was further utilized and expanded for analyses on Tehuelchesaurus, Comahuesaurus and related rebbachisaurs, Europasaurus, and Padillasaurus, before being expanded upon once again in 2017 by Carballido et al. during the description of Patagotitan to 405 characters and 87 taxa, including 28 titanosaurs (above and right).
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IGFBP-3 was first isolated, characterized, and quantitated in human plasma, in 1986. It has well-documented functions in the circulation, in the extracellular environment, and inside cells. It is the main IGF transport protein in the bloodstream, where it carries the growth factors predominantly in stable complexes that contain the binding protein, either IGF-1 or IGF-2, and a third protein called the acid-labile subunit or ALS. For IGFs to reach the tissues from the bloodstream, the circulating complexes are believed to partly dissociate, possibly enhanced by limited proteolysis of IGFBP-3. The IGF-1/IGFBP-3 ratio has sometimes been used as an index of IGF bioavailability in the human circulation, but this ignores IGF-1 binding to other IGFBPs (so the ratio is affected by the concentrations of all six IGFBPs), and the fact that IGF-2, which is three times more abundant than IGF-1 in the bloodstream of adults, occupies the majority of binding sites on circulating IGFBP-3.
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The chemical properties of Os3(CO)12 have been thoroughly examined. Direct reactions of ligands with the cluster often lead to complex product distributions because the inert Os–CO bonds require high temperatures to break, and at such high temperatures the initially formed adducts react further. More successfully, Os3(CO)12 is converted to more labile derivatives such as Os3(CO)11(MeCN) and Os3(CO)10(MeCN)2 using Me3NO as a decarbonylating agent.Nicholls, J. N.; Vargas, M. D. “Some Useful Derivatives of Dodecarbonyltriosmium” Inorganic Syntheses, 1990, volume 28, pages 232–235. . Os3(CO)11(MeCN) reacts with a variety of even weakly basic ligands to form adducts such as Os3(CO)11(ethylene) and Os3(CO)11(pyridine). The direct reaction of Os3(CO)12 with ethylene and pyridine results in degradation of these organic ligands to give the vinyl hydride HOs3(CO)10(η1,η2-C2H3) and the pyridyl-hydride HOs3(CO)10(NC5H4).
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Prostaglandin-endoperoxide synthase (PTGS), also known as cyclooxygenase (COX), is the key enzyme in prostaglandin biosynthesis. It converts free arachidonic acid, released from membrane phospholipids at the sn-2 ester binding site by the enzymatic activity of phospholipase A2, to prostaglandin (PG) H2. The reaction involves both cyclooxygenase (dioxygenase) and hydroperoxidase (peroxidase) activity. The cyclooxygenase activity incorporates two oxygen molecules into arachidonic acid or alternate polyunsaturated fatty acid substrates, such as linoleic acid and eicosapentaenoic acid. Metabolism of arachidonic acid forms a labile intermediate peroxide, PGG2, which is reduced to the corresponding alcohol, PGH2, by the enzyme’s hydroperoxidase activity. While metabolizing arachidonic acid primarily to PGG2, COX-1 also converts this fatty acid to small amounts of a racemic mixture of 15-Hydroxyicosatetraenoic acids (i.e., 15-HETEs) composed of ~22% 15(R)-HETE and ~78% 15(S)-HETE stereoisomers as well as a small amount of 11(R)-HETE. The two 15-HETE stereoisomers have intrinsic biological activities but, perhaps more importantly, can be further metabolized to a major class of anti-inflammatory agents, the lipoxins.
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The semantic shift is presumed to have arisen from the thorough hybridization or assimilation of the earliest Chinese or other non-indigenous settlers in the Malay Archipelago such that their ethnic heritage needed to be specified whenever referring to them, either to avoid confusion or to emphasise difference. The designator peranakan—in its original sense simply connoting "descendant of X ethnicity", or "the wombs of X"—emerged as the name for entire ethnic groups that were "locally born but non-indigenous" or perceived to be "hybrid" and "crossbred", and, in time, the latter meaning has come to predominate. It should also be noted that the broadness of the semantic range of peranakan means that it can have significantly different connotations in different parts of the Nusantara region and across different dialects or variants of the Malay and Indonesian languages. The word Peranakan, which can have very broad and labile meanings in Malay and Indonesian and, when used in common parlance, is simply an indicator of heritage or descent, may also be used to refer to other ethnic groups in the same region.
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