They should be able to visually do stuff to you kinetically with other senses.
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From the interior to the rims, which adjust kinetically as you drive, the FF 91 is not your typical car.
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Millie broke through as the kinetically gifted Eleven on Stranger Things, and Jacob gained fame singing on the defunct app Vine.
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I got pretty decent at kinetically repressing hostiles, because I was fit, I knew my duty and the terrorists had it coming.
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His songs limn classic Los Angeles gangster rap, but also that city's kinetically inventive progressive independent scene of the early-to-mid-1990s.
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Class war, gang war, colonialism, and its discontents—there are some core, kinetically unsettling truths about Vancouver, which is not to say the city can't change.
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Simple, graphic representations of the sun and moon swirl the Earth kinetically in a large, circular projection one moment, while an eclipse unfolds cinematically the next.
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Anchoring the program is Steve Reich's "Cello Counterpoint" from 2003, in which the live soloist weaves through the kinetically sparkling texture of seven recorded cello lines.
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Likewise, Schlemmer's kinetically activated "Danses des cerceaux" (1927) is made up of two machine figures that literally rise up and down, created only from rings of different sizes.
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Less abstractly, it's also a simple but kinetically animated music video for a wistful folk-pop song by songwriters Alexis Harte and JJ Wiesler, written specifically for the experience.
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The crowd felt a spark of bliss as the duo once known as Black Star skipped kinetically through the verses to "Thieves in the Night," from their 1999 album.
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Battery life will always be an issue, but I could imaging a solar or kinetically-powered watch with a drive train that could keep things topped up in between charges.
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The pilot, kinetically directed by Mr. Murphy, introduces a world — familiar from the 1990 documentary "Paris Is Burning" but never detailed like this in series TV — without feeling mechanical or overexpository.
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The push-pull of negative/positive space made the jetty seem even more kinetically alive and like the storm its shape resembled, one that messed with the intuitive logic of water behavior.
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While Pyongyang's propaganda missives are usually limited to blustery, even humorously over-the-top language, the regime lashes out strongly to any perceived insult of its leadership and has reacted kinetically to previous affronts to Kim.
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John, for instance, is a lot of fun, and his songs provide the backdrop for some kinetically exuberant action sequences — but the movie has already established a major emotional throughline involving the music of John Denver.
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Andy Serkis has played two of the most kinetically captivating creatures in recent film: the bounding ape Caesar, in the " Planet of the Apes " series, and the skulking hobbit Gollum, in the " Lord of the Rings " saga.
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The fact that you can't decide is what makes it most effective, and although the track's mood pushes and pulls in density—buoyed by kinetically shuffling, batida-esque rhythms—it never strays far from that elliptical, obscure narrative.
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But it wasn't until several years later in 2015, when Ortkrass and Koch entered a residency at Le Laboratoire and Harvard University, that they developed the framework to realize a series of sculptures exploring biological motion kinetically based on 15 points.
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A constellation of polka-dot biomorphic sculptures by Yayoi Kusama will populate a "town square" in the middle of Pier 94 and a word-based light sculpture by Ivan Navarro will respond kinetically to the noise level of visitor traffic near the entrance.
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In a circumstance where you have American forces on the ground that are directly being attacked by Russian aircraft, or Russian artillery, or whatnot, it's very hard to see how the United States military will not respond kinetically, and with violence, toward such an action.
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In contrast, rapid reactions involving acid anhydrides or acid chlorides are often kinetically-controlled.
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Ions are treated kinetically, but averaged over their gyro-obits and electrons are treated as drift-kinetic.
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In 2013, Joseph Fahys & Co began developing a luxury American-made smartwatch with a patent pending kinetically charged battery.
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Both of these oxidation states are kinetically inert. Many analogues of this ion have been prepared using different bridging ligands.
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Oxidation of [Co(II)(EDTA)]2− gives [Co(III)(EDTA)]−, which is so kinetically inert that it can be resolved optically.
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Cubane (C8H8) has been synthesized. Although it has high angle strain, cubane is kinetically stable, due to a lack of readily available decomposition paths.
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These particles can then be separated by gel electrophoresis (PAGE). If the synthesis is performed in a kinetically controlled manner, particularly stable representatives can be obtained with particles of uniform size (monodispersely), avoiding further separation steps.Manzhou Zhu, Eric Lanni, Niti Garg, Mark E. Bier, and Rongchao Jin: Kinetically Controlled, High-Yield Synthesis of Au25 Clusters, J. Am. Chem. Soc., 2008, 130 (4), 1138–1139 ().
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Proposed associative and redox mechanisms of the water gas shift reaction The WGSR has been extensively studied for over a hundred years. The kinetically relevant mechanism depends on the catalyst composition and the temperature. Two mechanisms have been proposed: an associative Langmuir–Hinshelwood mechanism and a redox mechanism. The redox mechanism is generally regarded as kinetically relevant during the high-temperature WGSR (> 350 °C) over the industrial iron-chromia catalyst.
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Germanium-tin alloys must be kinetically stabilized in order to prevent decomposition. Therefore, low temperature molecular beam epitaxy or chemical vapor deposition techniques are typically used for their synthesis.
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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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J. Am. Chem. Soc. 135 (41): 15338-15341. .Dasgupta, S.; Wu, J. (2011). “Template- directed synthesis of kinetically and thermodynamically stable molecular necklace using ring closing metathesis”. Org. Biomol. Chem.
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Cooling rates above 104 K/s are required to prevent crystallization of the droplets. At liquid nitrogen temperature, 77 K, HGW is kinetically stable and can be stored for many years.
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Mercury(II) hydride (systematically named mercurane(2) and dihydridomercury) is an inorganic compound with the chemical formula (also written as ). It is both thermodynamically and kinetically unstable at ambient temperature, and as such, little is known about its bulk properties. However, it known as a white, crystalline solid, which is kinetically stable at temperatures below , which was synthesised for the first time in 1951. Mercury(II) hydride is the second simplest mercury hydride (after mercury(I) hydride).
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Beckmann, Jens; Jurkschat, Klaus; Rabe, Stephanie; Schuermann, Markus "Hexakis(2,4,6-triisopropylphenyl)cyclotristannoxane - a molecular diorganotin oxide with kinetically inert Sn-O bonds" Zeitschrift für Anorganische und Allgemeine Chemie 2001, volume 627, 2413-2419.
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Kinetically, formation of clay minerals by reverse weathering can be relatively rapid (<1 year). Due to the short formation timescale, reverse weathering is seen as a reasonable contributor to various ocean biogeochemical cycles.
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Trifluoronitrosomethane Trifluoronitrosoethylene is deep blue gas. Although it is somewhat more kinetically stable due to its fluorine substituents, trifluoronitrosomethane, like other nitroso compounds, has a weak C–N bond of only 39.9 kcal/mol.
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Another, ZitB of E. coli (TC #2.A.4.1.4), has been reconstituted in proteoliposomes and studied kinetically. It appears to function by simple Me2+:H+ antiport with a 1:1 stoichiometry. Montanini et al.
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In many photo-productive systems this charge separation is kinetically isolated by delivery of the electron to a lower energy conductor attached to the p/n junction or into an electron transport chain. In this case some of the energy can be captured to do work. If the electron is not kinetically isolated thermodynamics will take over and the products will react with each other to regenerate the ground state starting material. This process is called recombination and the photon's energy is released as heat.
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These predictions proved quite accurate, although subsequent predictions for XeF8 indicated that it would be not only thermodynamically unstable, but kinetically unstable. As of 2013, XeF8 has not been made, although the octafluoroxenate(VI) anion () has been observed.
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Kv3.1/Kv3.2 conductance is necessary and kinetically optimized for high- frequency action potential generation. Kv3.1 channels are important for the high-firing frequency of auditory and fast-spiking GABAergic interneurons, retinal ganglion cells; regulation of action potential duration in presynaptic terminals.
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Many of derivatives feature kinetically inert cyclometalated ligands. Related half-sandwich complexes were central in the development of C-H activation. :Organoiridium chemistry has been central to the development of C-H activation, two examples of which are shown here.
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Disilene is a molecule with one Si=Si bond, and four equivalent Si-H bonds. Unlike ethylene, disilene is kinetically unstable with respect to tautomerisation. Disilene has two other tautomers, that are very close in energy: (μ2-H)disilene, and disilanylidene.
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Also, high organ specificity allows for the reduction of the injected activity, and thus the exposure to radiation, in the patient. The radiopharmaceutical must be kinetically inert, in that it must not change chemically in vivo en route to the target organ.
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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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ST2-PT (Single Transition-to-single Transition Polarization Transfer) is a method of sensitivity enhancement in NMR spectroscopy, developed by K.V. Pervushin, G. Wider, and K. Wüthrich in 1998. This method affords a sensitivity enhancement for kinetically stable amide 15N–1H groups in proteins.
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Tetrahedrane (C4H4) is a hypothetical compound. It has not yet been synthesized without substituents, but it is predicted to be kinetically stable in spite of its angle strain. Some stable derivatives, including tetra(tert- butyl)tetrahedrane (a hydrocarbon) and tetra(trimethylsilyl)tetrahedrane, have been produced.
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All chaperonins exhibit two states (open and closed), between which they can cycle. This cycling process is important during the folding of an individual polypeptide chain as it helps to avoid undesired interactions as well as to prevent the peptide from entering into kinetically trapped states.
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Kv3.1/Kv3.2 conductance is necessary and kinetically optimized for high-frequency action potential generation. Sometimes in heteromeric complexes with Kv3.1; important for the high- frequency firing of fast spiking GABAergic interneurons and retinal ganglion cells; and GABA release via regulation of action potential duration in presynaptic terminals.
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The most common type of frameshifting is −1 frameshifting or programmed −1 ribosomal frameshifting (−1 PRF). Other, rarer types of frameshifting include +1 and −2 frameshifting. −1 and +1 frameshifting are believed to be controlled by different mechanisms, which are discussed below. Both mechanisms are kinetically driven.
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Having history with Gambit (they met and clashed during a mission when they were mercenaries-for-hire), she immediately went after him and Bishop. However, Gambit was able to defeat her by hitting her with a kinetically charged tire."Uncanny X-Men" #298 (1993). Marvel Comics.
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Borneol can be synthesized by reduction of camphor by the Meerwein–Ponndorf–Verley reduction (a reversible process). Reduction of camphor with sodium borohydride (fast and irreversible) gives instead the isomer isoborneol as the kinetically controlled reaction product. :Synthesis of the borneol isomer isoborneol via reduction of camphor.
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Typically, single chain cyclized/knotted polymers are synthesized by deactivation enhanced ATRP of multivinyl monomers via kinetically controlled strategy. There are several main reactions during this polymerization process: initiation, activation, deactivation, chain propagation, intramolecular cyclization and intermolecular crosslinking. The polymerization process is explained in Figure 2. Figure 2.
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Lanthanide organometallic complexes have been synthesized by RT and RTLE. Lanthanides are very electropositive elements. Organomercurials, such as HgPh2, are common kinetically inert RT and RTLE reagents that allow functionalized derivatives to be synthesized, unlike organolithiums and Grignard reagents. Diarylmercurials are often used to synthesize lanthanide organometallic complexes.
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Although the kinetic model describes the physics accurately, it is more complex (and in the case of numerical simulations, more computationally intensive) than the fluid model. The hybrid model is a combination of fluid and kinetic models, treating some components of the system as a fluid, and others kinetically.
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It has been suggested that the former one is thermodynamically stable product, whereas the latter one is only kinetically stable. The reaction between BbtGeGeBbt and ethylene. Similarly, [2+2] cycloaddition reactions take place between digermynes and alkynes, for example PhC≡CPh, leading to the formation of 1,2-digermacyclobutadiene.
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The tripodal TAME ligand coordinates facially to metal ions. This stereochemical feature has been exploited in the preparation of platinum(IV) cage complexes, e.g., [Pt(tame)], which is a six coordinate Pt(IV) complex. Platinum in its +4 oxidation state has a d configuration and is kinetically inert.
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An additional concern was that the hydrogenation product has an unfavorable eutectic point, so it was impossible to isolate the crude intermediate in more than 94 percent ee by batch process. Because of this limitation, the process chemistry route toward LY500307 necessarily involved a kinetically controlled crystallization step after the hydrogenation to upgrade the enantiopurity of this penultimate intermediate to >99 percent ee. Comparison of the batch and continuous flow processes toward LY500307. The process chemistry team at Eli Lilly successfully developed a fully continuous process to this penultimate intermediate, including reaction, workup and kinetically controlled crystallization modules (the engineering considerations implicit in these efforts are beyond the scope of this article).
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Miniemulsions are kinetically stable but thermodynamically unstable. Oil and water are incompatible in nature, and the interface between them is not favored. Therefore, given a sufficient amount of time, the oil and water in miniemulsions separate again. Various mechanisms such as gravitational separation, flocculation, coalescence, and Ostwald ripening result in instability.
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Niles A. Pierce is an American mathematician, bioengineer, and professor at the California Institute of Technology. He is a leading researcher in the fields of molecular programming and dynamic nucleic acid nanotechnology. His research is focused on kinetically controlled DNA and RNA self-assembly. Pierce is working on applications in bioimaging.
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Typical for a heavy hydride (e.g., SbH3, H2Te, SnH4), AsH3 is unstable with respect to its elements. In other words, AsH3 is stable kinetically but not thermodynamically. ::2 AsH3 → 3 H2 \+ 2 As This decomposition reaction is the basis of the Marsh Test described below, which detects the elemental As.
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Inverted cucurbiturils are believed to be the kinetically controlled reaction products because the heating of iCB[6] in acidic medium results in a mixture of CB[5], CB[6] and CB[7] in a 24:13:1 ratio. A cucurbituril cut in half along the equator is called a hemicucurbituril.
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TY Bello was born in Ogun State. She attained a degree in economics from the University of Lagos. She briefly practised journalism and eventually ventured into photography. TY Bello emerged onto Nigeria's musical landscape as a member of the defunct group KUSH, an acronym for Kinetically Ushering Salvation into Hearts and Homes.
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In contrast to ethylene, which easily undergoes chlorine addition, ethane must first be functionalized by substitution reactions, which gives rise to a variety of consecutive and side-chain reactions. The reaction must, therefore, be kinetically controlled in order to obtain a maximal vinyl chloride yield. Vinyl chloride yields average 20–50% per pass.
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Synthesis of substituted phosphaalkynes via the intermediate silylated phosphaalkene. Heating these phosphaalkenes results in the formation of a phosphaalkyne and the expulsion of hexamethyldisiloxane (HMDSO). This method has been utilized to produce a variety of kinetically stable phosphaalkynes, including aryl, tertiary alkyl, secondary alkyl, and even primary alkyl phosphaalkynes in good yields.
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Exchange rates usually follow the trend I > Br > Cl. Alkyl- and arylfluoride are generally unreactive toward organolithium reagents. Lithium halogen exchange is kinetically controlled, and the rate of exchange is primarily influenced by the stabilities of the carbanion intermediates (sp > sp2 > sp3) of the organolithium reagents.The Preparation of Organolithium Reagents and Intermediates Leroux.F., Schlosser.
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Magnesite forms as surface moulds in such conditions but more generally occur as hydrous Mg- carbonates since their precipitation is kinetically favored. Most of the times, they derive C from DIC or nearby ultramafic complexes (e.g., Altin Playa, British Columbia, Canada). Magnesites in metamorphic rocks, on the other hand, indicate very high temperature of formation.
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The figure below is an example of an energy diagram for a compound with an (R) and (S) isomer.Hanefeld, U.; Veum, L. Tetrahedron: Asymmetry, 2004, 15, 3707–3709. Energy diagram of an (R) and (S) isomer. With addition of a catalyst, one transition state (TS) is lower and thus becomes the kinetically favored pathway.
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The method of slipping is one which exploits the thermodynamic stability of the rotaxane. If the end groups of the dumbbell are an appropriate size it will be able to reversibly thread through the macrocycle at higher temperatures. By cooling the dynamic complex, it becomes kinetically trapped as a rotaxane at the lower temperature.
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Meanwhile, Thing fights Namor in the sea beneath Utopia, and pins him beneath the teeth of a giant anglerfish. In the Savage Land, Captain America fights Gambit, who kinetically charges his suit, causing it to explode. However, Captain America survives the explosion and manages to knock out Gambit. In Latveria, Spider-Man fights Colossus, who injures him.
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In comparison to cationic cyclizations, radical cyclizations avoid issues associated with Wagner-Meerwein rearrangements, do not require strongly acidic conditions, and can be kinetically controlled. Cationic cyclizations are usually thermodynamically controlled. Radical cyclizations are much faster than analogous anionic cyclizations, and avoid β-elimination side reactions. Anionic Michael-type cyclization is an alternative to radical cyclization of activated olefins.
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Water at the top of the troposphere, particularly in liquid and solid states, cools as it emits net photons to space. Neighboring gas molecules other than water (e.g. Nitrogen) are cooled by passing their heat kinetically to the water. This is why temperatures at the top of the troposphere (known as the tropopause) are about -50 degrees Celsius.
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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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The pi-bonds of phosphaalkynes are weaker than most carbon-phosphorus sigma bonds, rendering phosphaalkynes reactive with respect to the formation of oligomeric species containing more sigma bonds. These oligomerization reactions are triggered thermally, or can be catalyzed by transition or main group metals. Synthesis of a cuboidal phosphaalkyne tetramer by heating a kinetically stable phosphaalkyne.
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Nightshade, a sequel to Shinobi, was later developed by Wow Entertainment and again published by Sega for the PlayStation 2. The game stars female ninja Hibana, who is stylistically and kinetically analogous to Hotsuma. Nightshades Japanese title Kunoichi refers to a female ninja, just as Shinobi refers to a male ninja. The gameplay is also structured similarly to Shinobis.
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While his powers are still kinetically based, they no longer appear to manifest as a "bubble field"; rather, his powers seem far more explosive in nature. In order to stimulate his powers, his Penance suit constantly rakes his flesh. Baldwin tolerates this to a masochistic degree, once stating that he would "wear [the suit] all the time if I could."Thunderbolts #113.
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When EDGs and EWGs are near the radical center, the stability of the radical center increases. The substituents can kinetically stabilize radical centers by preventing molecules and other radical centers from reacting with the center. The substituents thermodynamically stabilize the center by delocalizing the radical ion via resonance. These stabilization mechanisms lead to an enhanced rate for free-radical reactions.
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Some research suggests that it can be made by the cyclofunctionalization of cycloalkenyl systems. Under kinetically controlled conditions, this process generally results in exo cyclization and forms bridged ring systems like those found in picrotoxin. Additionally, several syntheses have been proposed for picrotoxinin and picrotin, the two molecules that make up picrotoxin. In 1980, a process to convert picrotoxinin to picrotin was discovered.
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In recent years he has expanded his ventures into large scale sculptures and installation art. His portable projection system, "The Engine" is a pioneering angle of Roberts' DIY practices. The work consists of a 2000-pound light and steel sculpture that kinetically supports a 17-foot screen. Hart, Hugh, "The Engine at LACMA's Muse 'til Midnight," Los Angeles Times, August 23, 2009.
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Unsubstituted tetrahedrane (C4H4) remains elusive, although it is predicted to be kinetically stable. One strategy that has been explored (but thus far failed) is reaction of propene with atomic carbon. Locking away a tetrahedrane molecule inside a fullerene has only been attempted in silico. Due to its bond strain and stoichiometry, tetranitrotetrahedrane has potential as a high-performance energetic material (explosive).
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Flash compositions used in firecrackers usually consist of a mixture of aluminium powder and potassium perchlorate. This mixture, sometimes called flash powder, is also used in ground and air fireworks. As an oxidizer, potassium perchlorate can be used safely in the presence of sulfur, whereas potassium chlorate cannot. The greater reactivity of chlorate is typical – perchlorates are kinetically poorer oxidants.
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The energy of an absorbed photon is transferred to electrons in the molecule and briefly changes their configuration (i.e., promotes the molecule from a ground state to an excited state). The excited state represents what is essentially a new molecule. Often excited state molecules are not kinetically stable in the presence of O2 or H2O and can spontaneously decompose (oxidize or hydrolyze).
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It was shown that hypercubane lifetime at room temperature tended to infinity. Therefore, it can be assumed that hypercubane is a kinetically stable molecular system. Among the possible hypercubane decomposition products at high temperatures (more than 1000 K) one can observe polycyclic airscrew-like hydrocarbon C34H18 based on three combined graphene fragments passivated by hydrogen atoms and three isolated acetylene molecules.
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Studies have been completed on the formation of the hydroxy ketones in the Robinson annulation reaction scheme. The trans compound is favored due to antiperiplanar effects of the final aldol condensation in kinetically controlled reactions. It has also been found though that the cyclization can proceed in synclinal orientation. The figure below shows the three possible stereochemical pathways, assuming a chair transition state.
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New York Rocker quickly proclaimed them "the most kinetically exciting new band."New York Rocker, October 1981. By 1981 and 1982 the band was performing in East Coast venues and colleges from Canada to Texas. Early shows found them sharing the stage with fellow New York and Boston bands such as DNA, Bush Tetras, Liquid Liquid, Mission of Burma, Raybeats, and Swans.
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Tryptophans: diastereocontrolled reaction The reaction of enantiopure tryptophan or its short-chain alkylesters leads to 1,2,3,4-tetrahydro-β-carbolines in which a new chiral center at C-1 adopts either a cis or trans configuration towards the C-3 carboxyl group. The cis conduction is kinetically controlled, i.e. it is performed at lower temperatures. At higher temperatures the reaction becomes reversible and usually favours racemisation.
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Charged and neutral particles in Vorpal can be represented by a fluid or kinetically using the PIC algorithm in either case self- consistently. The fields and particles can interact with arbitrarily shaped structures, including conductors, particle absorbers, reflectors, and many more. Accuracy is maintained using cut-cell techniques. The computational domain can be periodic or mimic boundaries at infinity via PML or other outgoing wave boundary conditions.
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Chromium(II) hydride, systematically named chromium dihydride and poly(dihydridochromium) is pale brown solid inorganic compound with the chemical formula (also written or ). Although it is thermodynamically unstable toward decomposition at ambient temperatures, it is kinetically metastable. Chromium(II) hydride is the second simplest polymeric chromium hydride (after chromium(I) hydride). In metallurgical chemistry, chromium(II) hydride is fundamental to certain forms of chromium-hydrogen alloys.
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Iron(I) hydride, systematically named iron hydride and poly(hydridoiron) is a solid inorganic compound with the chemical formula (also written or FeH). It is both thermodynamically and kinetically unstable toward decomposition at ambient temperature, and as such, little is known about its bulk properties. Iron(I) hydride is the simplest polymeric iron hydride. Due to its instability, it has no practical industrial uses.
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Planar rafts contain flotillin proteins and are found in neurons where caveolae are absent. Both types have similar lipid composition (enriched in cholesterol and sphingolipids). Flotillin and caveolins can recruit signaling molecules into lipid rafts, thus playing an important role in neurotransmitter signal transduction. It has been proposed that these microdomains spatially organize signaling molecules to promote kinetically favorable interactions which are necessary for signal transduction.
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This information is what provides motivation for the Pecoraro group. The initial studies have focused on understanding the binding of these heavy metals to peptides. Arsenic (As), mercury (Hg), and cadmium (Cd) all were used in systems with various peptides. Arsenic was found to bind to peptides via primarily a trigonal-pyramidal or tetrahedral shape in a manner that is both kinetically and thermodynamically favorable.
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Metastable and kinetically persistent species or systems are not considered truly stable in chemistry. Therefore, the term chemically stable should not be used by chemists as a synonym of unreactive because it confuses thermodynamic and kinetic concepts. On the other hand, highly chemically unstable species tend to undergo exothermic unimolar decompositions at high rates. Thus, high chemical instability may sometimes parallel unimolar decompositions at high rates.
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The compound can be produced by any one of three primary chemical conversion processes, involving either uranium tetrafluoride (UF4) or uranyl fluoride (UO2F2) as intermediates. It is generally considered to be the more attractive form for disposal purposes because, under normal environmental conditions, U3O8 is one of the most kinetically and thermodynamically stable forms of uranium. Its particle density is 8.3 g cm−3.
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These reactions are often performed in the presence of charcoal as a catalyst, or with hydrogen peroxide substituted for atmospheric oxygen. Other highly basic ligands, including carbonate, acetylacetonate, and oxalate, induce the formation of Co(III) derivatives. Simple carboxylates and halides do not. Unlike Co(II) complexes, Co(III) complexes are very slow to exchange ligands, so they are said to be kinetically inert.
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It can be looked at in terms of a change in the molecular motion of the liquid, not a change in the molecular order itself. This transition from liquid to solid is what defines the physical appearance of a standard lollipop. The result of the glass transition is a kinetically static state of a supercooled liquid. Prior to this, as stated before, the liquid was unstable.
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Cyclic and acyclic acetals on acetalated dextran which degrades to dextran, acetone, and ethanol. During the synthesis of acetalated dextran both acyclic and cyclic acetals are formed. The acyclic acetals degrade into an acetone and an alcohol, whereas cyclic acetals degrade into acetone. The ratio of cyclic to acyclic acetals varies with reaction time since acyclic acetals are kinetically favored and cyclic acetals are the thermodynamically favored.
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Atomic carbon, systematically named carbon and λ0-methane, also called monocarbon, is colourless gaseous inorganic chemical with the chemical formula C (also written [C]). It is kinetically unstable at ambient temperature and pressure, being removed through autopolymerisation. Atomic carbon is the simplest form of carbon, and is also the progenitor of carbon clusters. In addition, it may be considered to be the graphite monomer.
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Although it is not a nitrogen hydride, hydroxylamine (NH2OH) is similar in properties and structure to ammonia and hydrazine as well. Hydrazine is a fuming, colourless liquid that smells similarly to ammonia. Its physical properties are very similar to those of water (melting point 2.0 °C, boiling point 113.5 °C, density 1.00 g/cm3). Despite it being an endothermic compound, it is kinetically stable.
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Non-equilibrium thermodynamics is a branch of physics that studies the dynamics of statistical ensembles of molecules via unstable states. Being "stuck" in a thermodynamic trough without being at the lowest energy state is known as having kinetic stability or being kinetically persistent. The particular motion or kinetics of the atoms involved has resulted in getting stuck, despite there being preferable (lower-energy) alternatives.
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The ammines of chromium(III) and cobalt(III) are of historic significance. Both families of ammines are relatively inert kinetically, which allows the separation of isomers.Basolo, F.; Pearson, R. G. "Mechanisms of Inorganic Reactions." John Wiley and Son: New York: 1967. For example, tetraamminedichlorochromium(III) chloride, [Cr(NH3)4Cl2]Cl, has two forms - the cis isomer is violet, while the trans isomer is green.
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The phenoxide anion is a strong nucleophile with a nucleophilicity comparable to the one of carbanions or tertiary amines.. Mayr’s Database of Reactivity Parameters. Retrieved July 10, 2019. It can react at both its oxygen or carbon sites as an ambident nucleophile (see HSAB theory). Generally, oxygen attack of phenoxide anions is kinetically favored, while carbon-attack is thermodynamically preferred (see Thermodynamic versus kinetic reaction control).
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However, this is not observed in the polysilicon halides or hydrides because the Si=Si double bond in disilene compounds are much more reactive than C=C double bonds. Only when the substituent groups on silicon are very large are disilene compounds kinetically non-labile.R. West "The Chemistry of the Silicon-Silicon Double Bond" Angewandte Chemie Vol. 26, No. 12 (1987) pp. 1201-1211.
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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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Figure 3 Position of conduction and valence band of several semiconductors at pH = 1 shown vs NHE. Thermodynamic potentials for CO2 reduction to different products at pH = 1 vs NHE is shown beside the band edge positions of semiconductors. Thermodynamically, proton coupled multiple-electron reduction of CO2 is easier than single electron reduction. But to manage multiple proton coupled multiple-electron processes is a huge challenge kinetically.
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Internally graphitized tubes via acetylene thermal decomposition are passivated. Crystallization of molten α-B2O3 at ambient pressure is strongly kinetically disfavored (compare liquid and crystal densities). Threshold conditions for crystallization of the amorphous solid are 10 kbar and ~200 °C. Its proposed crystal structure in enantiomorphic space groups P31(#144); P32(#145) (e.g., γ-glycine) has been revised to enantiomorphic space groups P3121(#152); P3221(#154)(e.g.
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Ignition is spontaneous at room temperature with finely divided material as the high surface area allows the surface oxidation to rapidly heat the sample to the ignition temperature. Under standard conditions it is more stable than white phosphorus, but less stable than the thermodynamically stable black phosphorus. The standard enthalpy of formation of red phosphorus is -17.6 kJ/mol. Red phosphorus is kinetically most stable.
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In spite of its small enthalpy of formation (ΔHf° = −5.2 kcal/mol), it is kinetically stable, decomposing only at 400 °C. It is quite reactive towards reducing agents and anions, however, with the chlorine atom acting as an electrophile. It reacts explosively with reducing agents such as metal amides, metals, hydrides, etc. Its hydrolysis in water occurs very slowly, unlike that of chloryl fluoride.
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If, for example, a chemical process cannot be represented by equation (1), but needs to be represented by: A + B ↔ C1 ↔ C2 (6) all usual experimental methods used alone yield information on the global process A + B ↔ C2, which ignores the intermediate step. On the contrary, as shown in, kinITC used alone is able to dissect such a composite process both thermodynamically and kinetically. This means that kinITC allows dissecting the overall enthalpic term ΔH1+2 (obtained by a classical use of ITC) into ΔH1 \+ ΔH2, where ΔH1 pertains to the first step A + B ↔ C1, and ΔH2 pertains to the second step C1 ↔ C2. Furthermore, the two steps are also dissected kinetically, which means that the kinetic parameters kon and koff for the first step, as well as k1,2 and k2,1 for the second step, are also obtained.
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Macroemulsions are, by definition, not thermodynamically stable. This means that from the moment they are created, they are always reverting to their original, immiscible and separate state. The reason why Macroemulsions can exist however, is because they are kinetically stable rather than thermodynamically stable. This means that while they are continuously breaking down, it is done at such a slow pace that it is practically stable from a macroscopic perspective.
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Dihydridochromium, also systematically named chromane(2), is a related compound with the chemical formula (also written ). It is both thermodynamically and kinetically unstable at ambient temperature with the additional propensity to autopolymerise, and so cannot be concentrated. Dihydridochromium is the second simplest molecular chromium hydride (after hydridochromium), and is also the progenitor of clusters with the same stoichiometry. In addition, it may be considered to be the chromium(II) hydride monomer.
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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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Dubrovskii has made contributions to several fields of physics. ;Semiconductor nanostructures and nanowires He is best known for growth modeling of semiconductor nanostructures, particularly III-V nanowires. Starting from 2003, he has been at the forefront of research in this field, collaborating with more than 40 groups in 18 countries (with joint publications). His main area is in kinetically controlled engineering of nanostructures, including morphology, crustal phase, and size distributions.
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The dication is kinetically stable. An example of a stable diatomic dication which is not formed by oxidation of a neutral diatomic molecule is the dimercury dication . An example of a polyatomic dication is , formed by oxidation of S8 and unstable with respect to further oxidation over time to form SO2. Many organic dications can be detected in mass spectrometry for example (a complex) and the acetylene dication .
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The chelate ring is only slightly ruffled at the sp3-hybridized carbon and nitrogen centers. For those amino acids containing coordinating substituents, the resulting complexes are more structurally diverse since these substituents can coordinate. Histidine, aspartic acid, methionine, and cysteine sometimes form tridentate N,N,O, N,O,O, S,N,O, and S,N,O complexes, respectively. Using kinetically inert metal ions, complexes containing monodentate amino acids have been characterized.
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Because most heterocyclic bases contain multiple nucleophilic sites, site selectivity is an important issue in nucleoside synthesis. Purine bases, for instance, react kinetically at N3 and thermodynamically at N1 (see Eq. (4)). Glycosylation of thymine with protected 1-acetoxy ribose produced 60% of the N1 nucleoside and 23% of the N3 nucleoside. Closely related triazines, on the other hand, react with complete selectivity to afford the N2 nucleoside.
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During the early part of his career he was influenced by the ideas of Lars Gunnar Sillén and Robert Garrels regarding aqueous chemical equilibria. He developed models where the ideas by Sillén regarding equilibria were combined with improved descriptions of kinetically controlled reactions (i.e. slow reactions that do not reach equilibrium, e.g. weathering). He in particular made contributions to the knowledge of the reactions at the interface of minerals and water.
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Any reaction that decreases the overall Gibbs free energy of a system will proceed spontaneously (given that the system is isobaric and also adiabatic), although the reaction may proceed slowly if it is kinetically inhibited. The transfer of electrons from a high-energy molecule (the donor) to a lower-energy molecule (the acceptor) can be spatially separated into a series of intermediate redox reactions. This is an electron transport chain.
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Iron(II) hydride, systematically named iron dihydride and poly(dihydridoiron) is solid inorganic compound with the chemical formula (also written )n or ). ). It is kinetically unstable at ambient temperature, and as such, little is known about its bulk properties. However, it known as a black, amorphous powder, which was synthesised for the first time in 2014. Iron(II) hydride is the second simplest polymeric iron hydride (after iron(I) hydride).
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In contrast, at considerably lower temperatures, the configuration of the glass remains sensibly stable over increasingly extended periods of time. Thus, the liquid-glass transition is not a transition between states of thermodynamic equilibrium. It is widely believed that the true equilibrium state is always crystalline. Glass is believed to exist in a kinetically locked state, and its entropy, density, and so on, depend on the thermal history.
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Kinetically perfect enzymes have a specificity constant, kcat/Km, on the order of 108 to 109 M−1 s−1. The rate of the enzyme-catalysed reaction is limited by diffusion and so the enzyme 'processes' the substrate well before it encounters another molecule. Some enzymes operate with kinetics which are faster than diffusion rates, which would seem to be impossible. Several mechanisms have been invoked to explain this phenomenon.
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The thermal decomposition of 1,1-dimethyl-1-silacyclobutane and some reactions of an unstable intermediate containing a silicon–carbon double bond L. E. Gusel'Nikov and M. C. Flowers Chem. Commun. (London), 1967, 864–865, The first stable (kinetically shielded) silene was reported in 1981 by Brook.A solid silaethene: isolation and characterization Adrian G. Brook, Fereydon Abdesaken, Brigitte Gutekunst, Gerhard Gutekunst, R. Krishna Kallury J. Chem. Soc., Chem. Commun.
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This is also described as protein folding directed within funnel-like energy landscapes Some computational approaches to protein structure prediction have sought to identify and simulate the mechanism of protein folding. Levinthal also suggested that the native structure might have a higher energy, if the lowest energy was not kinetically accessible. An analogy is a rock tumbling down a hillside that lodges in a gully rather than reaching the base.
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Reaction takes place with all metals except the noble metals series and certain alloys. As a general rule, oxidizing reactions occur primarily with the concentrated acid, favoring the formation of nitrogen dioxide (NO2). However, the powerful oxidizing properties of nitric acid are thermodynamic in nature, but sometimes its oxidation reactions are rather kinetically non-favored. The presence of small amounts of nitrous acid (HNO2) greatly enhance the rate of reaction.
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Reminiscent of π-ligand exchange in coordination compounds, a phosphirenium ion may undergo alkyne exchange with other alkynes to give a mixture of phospinirenium species in equilibrium. Kinetically, elimination of alkyne from the cation is suggested to be rate-determining step. 337x337px In addition, the three-membered ring of phosphirenium ion may be broken. Successive reactions with suitable nucleophile are able to proceed on the electrophilic phosphorus atom.
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AFPs create a difference between the melting point and freezing point (busting temperature of AFP bound ice crystal) known as thermal hysteresis. The addition of AFPs at the interface between solid ice and liquid water inhibits the thermodynamically favored growth of the ice crystal. Ice growth is kinetically inhibited by the AFPs covering the water-accessible surfaces of ice. Thermal hysteresis is easily measured in the lab with a nanolitre osmometer.
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In coordination chemistry, a spectator ligand is a ligand that does not participate in chemical reactions of the complex. Instead, spectator ligands (vs "actor ligands") occupy coordination sites. Spectator ligands tend to be of polydentate, such that the M-spectator ensemble is inert kinetically. Although they do not participate in reactions of the metal, spectator ligands influence the reactivity of the metal center to which they are bound.
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General julia kocienski scheme The Julia- Kocienski Olefination, a further refinement of the Modified Julia olefination, offers very good E-selectivity. In the Julia–Kocienski olefination the alkylating agent is a tetrazole. It proceeds with the same mechanism as the benzothiazole sulfone above. The high E-selectivity of the Julia–Kocienski olefination is the result of kinetically controlled diastereoselective addition of metalated 1-phenyl-1H-tetrazol-5-yl (PT) sulfones to nonconjugated aldehydes.
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Arene- and cyclopentadienyl complexes are kinetically inert platforms for the design of new radiopharmaceuticals. Furthermore, there have been made studies utilizing exogenous semi-synthetic ligands; specifically to the dopamine transporter, observing increased resultant efficacy in regard to reward facilitating behavior (incentive salience) and habituation, namely with the phenyltropane compound [η6-(2β-carbomethoxy-3β-phenyl)tropane]tricarbonylchromium. Carbon monoxide releasing organometallic compounds are also actively investigated, due to the importance of carbon monoxide as a gasotransmitter.
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Fragment condensation is also undesirable since the coupled fragment must be in gross excess, which may be a limitation depending on the length of the fragment. A new development for producing longer peptide chains is chemical ligation: unprotected peptide chains react chemoselectively in aqueous solution. A first kinetically controlled product rearranges to form the amide bond. The most common form of native chemical ligation uses a peptide thioester that reacts with a terminal cysteine residue.
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In chemistry, redistribution usually refers to the exchange of anionic ligands bonded to metal and metalloid centers. The conversion does not involve redox, in contrast to disproportionation reactions. Some useful redistribution reactions are conducted at higher temperatures; upon cooling the mixture, the product mixture is kinetically frozen and the individual products can be separated. In cases where redistribution is rapid at mild temperatures, the reaction is less useful synthetically but still important mechanistically.
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The cubic shape requires the carbon atoms to adopt an unusually sharp 90° bonding angle, which would be highly strained as compared to the 109.45° angle of a tetrahedral carbon. Once formed, cubane is quite kinetically stable, due to a lack of readily available decomposition paths. It is the simplest hydrocarbon with octahedral symmetry. Having high potential energy but kinetic stability makes cubane and its derivative compounds useful for controlled energy storage.
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In contrast, the more smell- reliant contemporaneous anacoracid Squalicoraxs less advanced orbital but stronger olfactory processes was more suitable for an opportunistic scavenger. The jaws of C. mantelli were kinetically powerful. They have a slightly looser anterior curvature and a more robust build than that of the modern mako sharks, but otherwise were similar in general shape. The hyomandibula is elongated and was believed to swing laterally, which would allow jaw protrusion and deep biting.
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There has been significant controversy surrounding the kinetically relevant intermediate during the associative mechanism. Experimental studies indicate that both intermediates contribute to the reaction rate over metal oxide supported transition metal catalysts. However, the carboxyl pathway accounts for about 90% of the total rate owing to the thermodynamic stability of adsorbed formate on the oxide support. The active site for carboxyl formation consists of a metal atom adjacent to an adsorbed hydroxyl.
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With the exception of lutetium hydroxide, which has a cubic structure, they have the hexagonal UCl3 structure. The hydroxides can be precipitated from solutions of LnIII. They can also be formed by the reaction of the sesquioxide, Ln2O3, with water, but although this reaction is thermodynamically favorable it is kinetically slow for the heavier members of the series. Fajans' rules indicate that the smaller Ln3+ ions will be more polarizing and their salts correspondingly less ionic.
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Cerastotin is a more potent platelet proaggregant than cerastocytin because at a given amount it is just as active as an equal amount of crude venom. Pure cerastocytin, on the other hand, induces platelet aggregation six times slower than an equivalent volume of venom. However, while cerastotin is more kinetically favored than cerastocytin, it can only bind platelets in the presence of fibrinogen. Furthermore, its receptor binding site is not the same as that of thrombin.
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The fountain and its surrounding colonnades playfully appropriated classical forms and orders, executing them in modern materials (e.g., stainless steel, neon) or kinetically (e.g., suggesting the acanthus leaves of traditional Corinthian capitals through the use of water jets). The location ultimately chosen for the Piazza d'Italia was a city block sited in the semi-derelict upriver edge of downtown, four blocks from Canal Street and the edge of the French Quarter and three blocks from the Mississippi River.
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Matthias Pliessnig is an acclaimed furniture designer based in Brooklyn, New York.Rosecrans Baldwin April 23, 2009 Furniture Design The Digital Ramble New York Times blog whose work uses steam bent wood. His style is "kinetically contemporary" and he uses "computer-aided curves with laborious craftsmanship" to handcraft chairs and benches.The Eye; Next Generation Matthias Pliessnig page 36 March 2009 Forbes Life Pliessnig is a graduate of Rhode Island School of Design and the University of Wisconsin (Madison).
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However, while the second-generation Hoveyda and Grubbs catalysts were kinetically more active than the first-generation catalyst, reactions using these catalysts formed large amounts of dimeric and oligomeric products. # An epimerization risk under the cross-metathesis reaction conditions. The process chemistry group at Boehringer Ingelheim performed extensive mechanistic studies showing that epimerization most likely occurs through a ruthenacyclopentene intermediate. Furthermore, the Hoveyda catalyst employed in this scheme minimizes epimerization risk compared with the analogous Grubbs catalyst.
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These amphiphilic nanoparticles spontaneously assembled at the water-dichloromethane interface. In 2010, Janus particles composed from silica and polystyrene, with the polystyrene portion loaded with nanosized magnetite particles, were used to form kinetically stable oil-in-water emulsions that can be spontaneously broken on application of an external magnetic field. Such Janus materials will find applications in magnetically controlled optical switches and other related areas. The first real applications of Janus nanoparticles were in polymer synthesis.
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Elle befriends Gabriel and the two begin to share feelings for each other. Against her wishes, Elle helps Noah manipulate him to kill again by introducing Gabriel to Trevor Zeitlan, a young man who can kinetically shatter objects by "shooting" at them with his thumb and forefinger. She purposefully enrages Gabriel by having Trevor repeatedly demonstrate his ability by shattering glasses while calling him "special." Gabriel turns on Elle, who tries to stop him from killing Trevor.
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Schematic of "tight" and "loose" transition state complexes for a hypothetical ion ABCD+. Like all chemical reactions, the unimolecular decomposition of ions is subject to thermodynamic versus kinetic reaction control: the kinetic product forms faster, whereas the thermodynamic product is more stable. In the decomposition of ABCD+, the reaction to form AD+ is thermodynamically favored and the reaction to form AB+is kinetically favored. This is because the AD+ reaction has favorable enthalpy and the AB+ has favorable entropy.
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The position of the alkene in the product is controlled by the site of deprotonation by the organolithium base. In general, the kinetically favored, less substituted site of differentially substituted tosylhydrazones is deprotonated selectively, leading to the less substituted vinyllithium intermediate. Although many secondary reactions exist for the vinyllithium functional group, in the Shapiro reaction in particular water is added, resulting in protonation to the alkene. Other reactions of vinyllithium compounds include alkylation reactions with for instance alkyl halides.
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Additionally, the formation of this complex enables glutamate to react with aminotransferase without interfering activity of malate dehydrogenase. The formation of this ternary complex also facilitates the release of oxaloacetate from malate dehydrogenase to aminotransferase. Kinetically, the binding of malate dehydrogenase to the binary complex of alpha ketoglutarate dehydrogenase and aminotrannferase has been shown to increase reaction rate of malate dehydrogenase because the Km of malate dehydrogenase is decreased when it is bound as part of this complex.
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Organometallic agents are often handled in etheric solvents, which coordinate to the metallic centers and thereby enhance the reactivity of the organic rests. Here, the ether cleavage poses a problem, as it does not only decompose the solvent, but also uses up the organometallic agent. Reactions with organometallic agents are therefore typically performed at low temperatures (-78 °C). At these temperatures, deprotonation is kinetically inhibited and slow compared to many reactions that are intended to take place.
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Several enzymes in the bacteria have been proposed as tentative drug targets. For example, enzymes in the iron uptake pathway have been suggested as important drug targets. Further, a cN-II class of IMP/GMP specific 5´-nucleotidase which has been extensively characterized kinetically. The tetrameric enzyme shows aspects of positive homotropic cooperativity, substrate activation and presents a unique allosteric site that can be targeted to design effective drugs against the enzyme and thus, the organism.
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Regardless it is this step that kinetically imparts the chemoselectivity to the overall transformation. Stronger, more electron-rich bonds are activated preferentially over weaker, more electron-poor bonds of species that have already been partially oxidized. This avoids a problem that plagues many partial oxidation processes, namely, the over-oxidation of substrate to thermodynamic sinks such as H2O and CO2. In the next step the PtII-CH2R complex is oxidized by [PtIVCl6]2− to a PtIV-CH2R complex.
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Energy input – through shaking, stirring, homogenizing, or exposure to power ultrasound – is needed to form an emulsion. Over time, emulsions tend to revert to the stable state of the phases comprising the emulsion. An example of this is seen in the separation of the oil and vinegar components of vinaigrette, an unstable emulsion that will quickly separate unless shaken almost continuously. There are important exceptions to this rule – microemulsions are thermodynamically stable, while translucent nanoemulsions are kinetically stable.
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As the most commonly available ruthenium compound, RuCl3·xH2O is the precursor to many hundreds of chemical compounds. The noteworthy property of ruthenium complexes, chlorides and otherwise, is the existence of more than one oxidation state, several of which are kinetically inert. All second and third-row transition metals form exclusively low spin complexes, whereas ruthenium is special in the stability of adjacent oxidation states, especially Ru(II), Ru(III) (as in the parent RuCl3·xH2O) and Ru(IV).
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Singlet oxygen, systematically named dioxygen(singlet) and dioxidene, is a gaseous inorganic chemical with the formula O=O (also written as or ), which is in a quantum state where all electrons are spin paired. It is kinetically unstable at ambient temperature, however the rate of decay is slow. The lowest excited state of the diatomic oxygen molecule is a singlet state. It is a gas with physical properties differing only subtly from those of the more prevalent triplet ground state of O2.
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In the second step, degalactosylation, the covalent bond is broken when Glu461 accepts a proton, replacing the galactose with water. Two transition states occur in the deep site of the enzyme during the reaction, once after each step. When water participates in the reaction, galactose is formed, otherwise, when D-glucose acts as the acceptor in the second step, transgalactosylation occurs . It has been kinetically measured that single tetramers of the protein catalyze reactions at a rate of 38,500 ± 900 reactions per minute.
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Diatomic carbon (systematically named dicarbon and 1λ2,2λ2-ethene), is a green, gaseous inorganic chemical with the chemical formula C=C (also written [C2] or C2. It is kinetically unstable at ambient temperature and pressure, being removed through autopolymerisation. It occurs in carbon vapor, for example in electric arcs; in comets, stellar atmospheres, and the interstellar medium; and in blue hydrocarbon flames. Diatomic carbon is the second simplest form of carbon after atomic carbon, and is an intermediate participator in the genesis of fullerenes.
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The kinetic (or coagulation) approach preserves the integrity of any and all structures created during network formation. Thus, an infinite set of differential rate equations (one for each possible structure, of which there essentially infinite) must be created in order to treat gel systems kinetically. Consequently, exact solutions for kinetic theories can be obtained for only the most basic systems.Dusek, K.; Kuchanov, S. I.; Panyukov, S. V. In Polymer Networks ’91; Dusek, K and Kuchanov, S. I., eds.; VSP: Utrecht, 1992; Chap.
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A useful alternative to the methods described here that avoids the site selectivity concerns of the SHJ reaction is tandem Michael reaction/cyclization to simultaneously form the heterocyclic base and establish its connection to the sugar moiety.Nair, V.; Purdy, D. F. Heterocycles 1993, 36, 421. (10)File:NucleoAlt1.png A second alternative is enzymatic transglycosylation, which is completely kinetically controlled (avoiding issues of chemical transglycosylation associated with thermodynamic control). However, operational complications associated with the use of enzymes are a disadvantage of this method.
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Photodegradation of a plastic bucket used as an open- air flowerpot for some years Many organic chemicals are thermodynamically unstable in the presence of oxygen; however, their rate of spontaneous oxidation is slow at room temperature. In the language of physical chemistry, such reactions are kinetically limited. This kinetic stability allows the accumulation of complex environmental structures in the environment. Upon the absorption of light, triplet oxygen converts to singlet oxygen, a highly reactive form of the gas, which effects spin-allowed oxidations.
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TNT is a reactive molecule and is particularly prone to react with reduced components of sediments or photodegradation in the presence of sunlight. TNT is thermodynamically and kinetically capable of reacting with a wide number of components of many environmental systems. This includes wholly abiotic reactants, like photons, hydrogen sulfide, Fe2+, or microbial communities, both oxic and anoxic. Soils with high clay contents or small particle sizes and high total organic carbon content have been shown to promote TNT transformation.
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Figure 3 shows that thermodynamically, some of the proton-coupled multi-electron CO2 reductions are within semiconductors band gap. This makes it feasible to photo-reduce CO2 on p-type semiconductors. Various p-type semiconductors have been successfully employed for CO2 photo reduction including p-GaP, p-CdTe, p-Si, p-GaAs, p-InP, and p-SiC. Kinetically, however, these reactions are extremely slow on given semiconductor surfaces; this leads to significant overpotential for CO2 reduction on these semiconductor surfaces.
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Molecular recognition and self-assembly may be used with reactive species in order to pre-organize a system for a chemical reaction (to form one or more covalent bonds). It may be considered a special case of supramolecular catalysis. Non-covalent bonds between the reactants and a "template" hold the reactive sites of the reactants close together, facilitating the desired chemistry. This technique is particularly useful for situations where the desired reaction conformation is thermodynamically or kinetically unlikely, such as in the preparation of large macrocycles.
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Fischer esterification is an example of nucleophilic acyl substitution based on the electrophilicity of the carbonyl carbon and the nucleophilicity of an alcohol. However, carboxylic acids tend to be less reactive than esters as electrophiles. Additionally, in dilute neutral solutions they tend to be deprotonated anions (and thus unreactive as electrophiles). Though very kinetically slow without any catalysts (most esters are metastable), pure esters will tend to spontaneously hydrolyse in the presence of water, so when carried out "unaided", high yields for this reaction is quite unfavourable.
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In this process, G-actin subunits primarily add to the "barbed end" of the filamentous polymer. This end proves to be both more thermodynamically favored for the addition of G-actin and kinetically dynamic as well. Simultaneously, older G-actin monomers "fall off" of the pointed end of the microfilament. At the "pointed end" of the F-actin polymer, actin monomers are bound to ADP, which dissociates more readily and rapidly than ATP-bound actin, which is found at the "barbed end" of the polymer.
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The key enzyme of this pathway, carbon monoxide dehydrogenase/acetyl-CoA synthase, harbors mixed nickel-iron- sulfur clusters in its reaction centers and catalyzes the formation of acetyl- CoA (similar to acetyl-thiol) in a single step. There are increasing concerns, however, that prebiotic thiolated and thioester compounds are thermodynamically and kinetically unfavorable to accumulate in presumed prebiotic conditions (i.e. hydrothermal vents). It has also been proposed that cysteine and homocysteine may have reacted with nitriles resulting from the Stecker reaction, readily forming catalytic thiol-reach poplypeptides.
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Aminoacyl-tRNA synthetases have been kinetically studied, showing that Mg2+ ions play an active catalytic role and therefore aaRs have a degree of magnesium dependence. Increasing the Mg2+ concentration leads to an increase in the equilibrium constants for the aminoacyl-tRNA synthetases’ reactions. Although this trend was seen in both class I and class II synthetases, the magnesium dependence for the two classes are very distinct. Class II synthetases have two or three (more frequently three) Mg2+ ions, while class I only requires one Mg2+ ion.
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Whether the chelate dissociated and resulted in 64Cu binding to the protein superoxide dismutase (SOD) in rat liver was investigated by utilizing a gel electrophoresis assay for the detection of SOD. It was shown that 64Cu did in fact dissociate from the TETA chelator and bound to SOD, and to a lesser extent, other proteins. This is caused either because chelate-biomolecules are not thermodynamically stable or are not kinetically stable. Kinetic stability is more central in the determination of in vivo stability than thermodynamic stability however.
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The theoretical maximum for the specificity constant is called the diffusion limit and is about 108 to 109 (M−1 s−1). At this point every collision of the enzyme with its substrate will result in catalysis, and the rate of product formation is not limited by the reaction rate but by the diffusion rate. Enzymes with this property are called catalytically perfect or kinetically perfect. Example of such enzymes are triose-phosphate isomerase, carbonic anhydrase, acetylcholinesterase, catalase, fumarase, β-lactamase, and superoxide dismutase.
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Ring-closing metathesis, conversely, usually involves the formation of a five- or six-membered ring, which is enthalpically favorable; although these reactions tend to also evolve ethylene, as previously discussed. RCM has been used to close larger macrocycles, in which case the reaction may be kinetically controlled by running the reaction at high dilutions. The same substrates that undergo RCM can undergo acyclic diene metathesis, with ADMET favored at high concentrations. The Thorpe–Ingold effect may also be exploited to improve both reaction rates and product selectivity.
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With a catalyst, a reaction which is kinetically inhibited by a high activation energy can take place in circumvention of this activation energy. Heterogeneous catalysts are usually solids, powdered in order to maximize their surface area. Of particular importance in heterogeneous catalysis are the platinum group metals and other transition metals, which are used in hydrogenations, catalytic reforming and in the synthesis of commodity chemicals such as nitric acid and ammonia. Acids are an example of a homogeneous catalyst, they increase the nucleophilicity of carbonyls, allowing a reaction that would not otherwise proceed with electrophiles.
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Action potentials in vertebrate neurons are followed by an afterhyperpolarization (AHP) that may persist for several seconds and may have profound consequences for the firing pattern of the neuron. Each component of the AHP is kinetically distinct and is mediated by different calcium-activated potassium channels. The KCa2.2 protein is activated before membrane hyperpolarization and is thought to regulate neuronal excitability by contributing to the slow component of synaptic AHP. KCa2.2 is an integral membrane protein that forms a voltage-independent calcium-activated channel with three other calmodulin-binding subunits.
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Lipid raft organisation, region (1) is standard lipid bilayer, while region (2) is a lipid raft. The plasma membranes of cells contain combinations of glycosphingolipids, cholesterol and protein receptors organised in glycolipoprotein lipid microdomains termed lipid rafts. Their existence in cellular membranes remains somewhat controversial. It has been proposed that they are specialized membrane microdomains which compartmentalize cellular processes by serving as organising centers for the assembly of signaling molecules, allowing a closer interaction of protein receptors and their effectors to promote kinetically favorable interactions necessary for the signal transduction.
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The transport equations for the mass fractions of the constituents are solved using this rate of reaction. Apart from this a mean enthalpy equation is also solved and temperature, density and viscosity are calculated accordingly. The model can also be implemented when finite rate kinetically controlled reaction is to be simulated. In such situation while deciding the rate of the reaction the Arrhenius kinetic rate expression is also taken into account and the rate of reaction is taken as minimum amongst the turbulent dissipation rates of all the constituents and the Arrhenius kinetic rate expression.
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Organic Chemistry, 3rd ed., M. A. Fox & J. K. Whitesell, Jones & Bartlett, 2004 A Guidebook to Mechanism in Organic Chemistry, 6th Edition, Peter Sykes, Pearson Prentice Hall, 1986. Introduction to Organic Chemistry I, Seth Robert Elsheimer, Blackwell Publishing, 2000 The conditions of the reaction, such as temperature, pressure, or solvent, affect which reaction pathway may be favored: either the kinetically controlled or the thermodynamically controlled one. Note this is only true if the activation energy of the two pathways differ, with one pathway having a lower Ea (energy of activation) than the other.
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The STX was built in 1998. The STX was motivated by a discovery from an unrelated experiment; a few years previously, the Large-S Experiment (LSX) had demonstrated the existence of a kinetically stabilized parameter regime which appeared advantageous for a fusion reactor. However, the LSX experiment formed FRCs in a power-hungry, violent way called a theta-pinch. The US Department of Energy funded the Translation Confinement Sustainment (TCS) program as a follow-on to the LSX program, but it had not yet begun when the STX started operation.
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In the 1990s, the Large-S Experiment (LSX) had demonstrated that there exist kinetically stabilized regimes of operation in which FRC reactors could operate. However, the LSX used a method of forming FRCs called a theta-pinch, which does not allow FRCs to be further sustained and heated. The US Department of Energy funded the TCS program as an extension of LSX, in order to demonstrate the RMF method of sustaining FRCs formed via the theta-pinch method. TCS was contemporary with other RMF-FRCs such as the STX, the PV Rotamak, and the PFRC.
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The unreacted starting material can be racemized in situ, thus making this a dynamic kinetic resolution. 500px In addition, lipases are used extensively for kinetic resolution in both academic and industrial settings. Lipases have been used to resolve primary alcohols, secondary alcohols, a limited number of tertiary alcohols, carboxylic acids, diols, and even chiral allenes. Lipase from Pseudomonas cepacia (PSL) is the most widely used in the resolution of primary alcohols and has been used with vinyl acetate as an acylating agent to kinetically resolve the primary alcohols shown below.
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This is critical because any sigmoidal unfolding curve, irrespective of the degree of cooperativity, can be fit to a two-state model. Kinetically, the presence of a barrier guarantees a single-exponential, but not vice versa. Nevertheless, in some proteins such as the yeast phosphoglycerate kinase and a mutant human ubiquitin, non-exponential kinetics suggesting downhill folding have been observed. A proposed solution to these problems is to develop models that can differentiate between the different situations, and identify simple but robust experimental criteria for identifying downhill folding proteins.
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A nanocoulombmeter, in combination with a Faraday cup, can be used to detect and measure the beams emitted from electron guns and ion guns. The Faraday cup consists of a shielded cup with an aperture, which collects the kinetically active electrons or ions, and an output wire, which is connected to an nanocoulombmeter. The Faraday cup can be completely separate from the gun, or it can be part of an assembly mounted to the end of the electron/ion gun and manipulated remotely. Some Faraday cup assemblies include a phosphor screen as well.
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The dynamics of surfactant adsorption is of great importance for practical applications such as in foaming, emulsifying or coating processes, where bubbles or drops are rapidly generated and need to be stabilized. The dynamics of absorption depend on the diffusion coefficient of the surfactant. As the interface is created, the adsorption is limited by the diffusion of the surfactant to the interface. In some cases, there can exist an energetic barrier to adsorption or desorption of the surfactant. If such a barrier limits the adsorption rate, the dynamics are said to be ‘kinetically limited'.
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Once ATP is bound to the B-Raf kinase domain, D576 of the catalytic loop activates a substrate hydroxyl group, increasing its nucleophilicity to kinetically drive the phosphorylation reaction while other catalytic loop residues stabilize the transition state.(Figure 2). N581 chelates the divalent magnesium cation associated with ATP to help orient the molecule for optimal substitution. K578 neutralizes the negative charge on the γ-phosphate group of ATP so that the activated ser/thr substrate residue won't experience as much electron-electron repulsion when attacking the phosphate.
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Telluric acid is formed by the oxidation of tellurium or tellurium dioxide with a powerful oxidising agent such as hydrogen peroxide, chromium trioxide or sodium peroxide. :TeO2 \+ H2O2 \+ 2 H2O → Te(OH)6 Crystallization of telluric acid solutions below 10 °C gives Te(OH)6·4H2O. It is oxidizing, as shown by the electrode potential for the reaction below, although it is kinetically slow in its oxidations. :H6TeO6 \+ 2 H+ \+ 2 e− ⇌ TeO2 \+ 4 H2O E ~~o~~ = +1.02 V Chlorine, by comparison, is +1.36 V and selenous acid is +0.74 V in oxidizing conditions.
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Once a corrupted soul has helped him a certain number of times, it is allowed to pass on to Heaven, having earned redemption for the sins it committed in life that would have sent it to Hell if it had simply died in the normal manner. Also, Ragman possesses a number of minor magical powers, such as kinetically controlling the suit (i.e. entangling Eclipso with his cloak while grappling with her). The suit will also automatically materialize whenever he is in danger, and will normally teleport him to wherever he is needed.
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This is due to a fast catalytic step, which produces the light, and a slow regeneration step, where the oxyluciferin is freed and another molecule of luciferin is then enabled to bind to the enzyme. Because of the kinetically slow step, each aequorin molecule must "recharge" with another molecule of luciferin before it can emit light again, and this makes it appear as though it is not behaving as a typical enzyme. Photoproteins form a stable luciferin- photoprotein complex, often until the addition of another required factor such as Ca2+ in the case of aequorin.
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Besides the precisely placed glutamate and histidine residues to form the enediol, a ten- or eleven-amino acid chain of TPI acts as a loop to stabilize the intermediate. The loop, formed by residues 166 to 176, closes and forms a hydrogen bond to the phosphate group of the substrate. This action stabilizes the enediol intermediate and the other transition states on the reaction pathway. In addition to making the reaction kinetically feasible, the TPI loop sequesters the reactive enediol intermediate to prevent decomposition to methylglyoxal and inorganic phosphate.
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Graphical representation of a rotaxane cyclobis(paraquat-p-phenylene) macrocycle. A rotaxane is a mechanically interlocked molecular architecture consisting of a "dumbbell shaped molecule" which is threaded through a "macrocycle" (see graphical representation). The name is derived from the Latin for wheel (rota) and axle (axis). The two components of a rotaxane are kinetically trapped since the ends of the dumbbell (often called stoppers) are larger than the internal diameter of the ring and prevent dissociation (unthreading) of the components since this would require significant distortion of the covalent bonds.
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Octaazacubane is a hypothetical explosive allotrope of nitrogen with formula N8, whose molecules have eight atoms arranged into a cube. (By comparison, nitrogen usually occurs as the diatomic molecule N2.) It can be regarded as a cubane-type cluster, where all eight corners are nitrogen atoms bonded along the edges. It is predicted to be a metastable molecule, in which despite the thermodynamic instability caused by bond strain, and the high energy of the N–N single bonds, the molecule remains kinetically stable for reasons of orbital symmetry.
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While most steps in gluconeogenesis are the reverse of those found in glycolysis, three regulated and strongly endergonic reactions are replaced with more kinetically favorable reactions. Hexokinase/glucokinase, phosphofructokinase, and pyruvate kinase enzymes of glycolysis are replaced with glucose-6-phosphatase, fructose-1,6-bisphosphatase, and PEP carboxykinase/pyruvate carboxylase. These enzymes are typically regulated by similar molecules, but with opposite results. For example, acetyl CoA and citrate activate gluconeogenesis enzymes (pyruvate carboxylase and fructose-1,6-bisphosphatase, respectively), while at the same time inhibiting the glycolytic enzyme pyruvate kinase.
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Based on 231 reviews collected by the film review aggregator Rotten Tomatoes, 87% of critics gave 28 Days Later a positive review, with an average rating of 7.38/10. The site's consensus reads: "Kinetically directed by Danny Boyle, 28 Days Later is both a terrifying zombie movie and a sharp political allegory." On Metacritic, the film received a rating of 73 (out of 100) based on 39 reviews. Bravo awarded it the 100th spot on their list of The 100 Scariest Movie Moments with the commentators explaining that making the zombies move fast for the first time was a bright and effective idea.
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This is essential for observing unquenchable phases of matter because they are kinetically and thermodynamically unstable at low temperatures and pressure. Viscosity and density of high-pressure melts can be measured in-situ using the sink float method and neutron tomography. In this method a sample is implanted with objects, such platinum spheres, that have different density and neutron scattering properties compared to the material surrounding them, and the path of the object is tracked as it sinks, or floats, through the melt. Two objects with contrasting buoyancy can be used simultaneously to calculate the density.
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Thermodynamic stability applies to a particular system. The reactivity of a chemical substance is a description of how it might react across a variety of potential chemical systems and, for a given system, how fast such a reaction could proceed. Chemical substances or states can persist indefinitely even though they are not in their lowest energy state if they experience metastability - a state which is stable only if not disturbed too much. A substance (or state) might also be termed "kinetically persistent" if it is changing relatively slowly (and thus is not at thermodynamic equilibrium, but is observed anyway).
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Many compounds have the ability to crystallize with some having different crystal structures, a phenomenon called polymorphism. Certain polymorphs may be metastable, meaning that although it is not in thermodynamic equilibrium, it is kinetically stable and requires some input of energy to initiate a transformation to the equilibrium phase. Each polymorph is in fact a different thermodynamic solid state and crystal polymorphs of the same compound exhibit different physical properties, such as dissolution rate, shape (angles between facets and facet growth rates), melting point, etc. For this reason, polymorphism is of major importance in industrial manufacture of crystalline products.
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Potassium intermediate/small conductance calcium-activated channel, subfamily N, member 1 , also known as KCNN1 is a human gene encoding the KCa2.1 protein. Action potentials in vertebrate neurons are followed by an afterhyperpolarization (AHP) that may persist for several seconds and may have profound consequences for the firing pattern of the neuron. Each component of the AHP is kinetically distinct and is mediated by different calcium-activated potassium channels. The protein encoded by this gene is activated before membrane hyperpolarization and is thought to regulate neuronal excitability by contributing to the slow component of synaptic AHP.
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The Mg2+-dependent currents carried by XntAp are kinetically like that of a channel protein and have an ion selectivity order of Mg2+ > Co2+, Mn2+ > Ca2+ — a series again very similar to that of CorA. Unlike the other transport proteins reported so far, XntAp is dependent on intracellular Ca2+. The transport is also dependent on ΔΨ, but again Mg2+ is not transported to equilibrium, being limited to approximately 0.4 mM free Mg2+ in the cytoplasm. The existence of an intracellular compartment with a much higher free concentration of Mg2+ (8 mM) was supported by the results.
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This is essential for observing unquenchable phases of matter because they are kinetically and thermodynamically unstable at low temperatures and pressure. Viscosity and density of high-pressure melts can be measured in-situ using the sink float method and neutron tomography. In this method a sample is implanted with objects, such platinum spheres, that have different density and neutron scattering properties compared to the material surrounding them, and the path of the object is tracked as it sinks, or floats, through the melt. Two objects with contrasting buoyancy can be used simultaneously to calculate the density.
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Radon hexafluoride (), the heavier homologue of xenon hexafluoride, has been studied theoretically, but its synthesis has not yet been confirmed. Higher fluorides of radon may have been observed in experiments where unknown radon-containing products distilled together with xenon hexafluoride, and perhaps in the production of radon trioxide: these may have been RnF4, RnF6, or both. It is likely that the difficulty in identifying higher fluorides of radon stems from radon being kinetically hindered from being oxidised beyond the divalent state. This is due to the strong ionicity of RnF2 and the high positive charge on Rn in RnF+.
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HGeGeH Digermynes are a class of compounds that are regarded as the heavier digermanium analogues of alkynes. The parent member of this entire class is HGeGeH, which has only been characterized computationally, but has revealed key features of the whole class. Because of the large interatomic repulsion between two Ge atoms, only kinetically stabilized digermyne molecules can be synthesized and characterized by utilizing bulky protecting groups and appropriate synthetic methods, for example, reductive coupling of germanium(II) halides. The bonding between two Ge atoms in digermyne is different from C≡C bond in alkynes, which results in the trans-bent structure of digermyne.
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Gambit (of Weapon X) is allowed to deliver the killing blow against King Hyperion with a kinetically charged sword of the slain Magik which causes an explosion that kills them both, leaving five Exiles alive and their mission complete. The Exiles visit the main Marvel Universe for a second timeExiles #46-48 where they are joined by Namora, who replaces Magik, and are instructed to "leave their possessions and earn their wings". Reed Richards deduces this means they are to leave Nocturne behind (whose power involves possession) and have Beak join the Exiles, which is confirmed by the Timebroker.
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The URR is designed to measure the amount of dialysis given when the dialysis clearance of urea greatly exceeds the urea generation rate. In continuous hemodialysis or in peritoneal dialysis, for example, a considerable amount of dialysis is delivered, but the urea level remains roughly constant after the initial treatment of uremia, so the URR is essentially zero. In long slow overnight dialysis, if simplified equations are used, the URR also underestimates the amount of dialysis due to urea generation during the long dialytic session. For this reason, the kinetically modeled Kt/V is always recommended as the best measure of dialysis adequacy.
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'Extensums' are usually outdoor works, which 'extend' a space in Rhodes' terms; 'intensums' are usually installations inside buildings, where space is intensifed. Rhodes began training as a cross-country runner in 1978 and went on to compete regularly in marathon and cross-country events. In 1998 art historian Priscilla Pitts wrote: > Every day she runs long distances on the hills, often along Summit Road, > 'absorbing the landforms' not just with her eyes, but also through the soles > of her feet. She becomes kinetically intimate with the landscape, her whole > body responding to the varying nature of the terrain.
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The rate of pseudo-first-order decay of this model enediyne is highly dependent on the solvent hydrogen-donor ability, indicating that the hydrogen abstraction step following biradical formation is kinetically significant in the cycloaromatization of the enediyne, as opposed to acyclic systems, where formation of the biradical itself is known to be the rate-limiting step. It is noteworthy that of the solvents examined, tetrahydrofuran—structurally homologous with deoxyribose—led to comparatively fast decomposition of the 5,9-fused enediyne scaffold (t½ = 68 min); Zein et al. independently remark that deoxyribose 4'-hydrogen abstraction is most likely operative in kedarcidin chromophore bioactivity.
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However, to realize a covalent analogue of chain-growth supramolecular polymerization, a challenging prerequisite is the design of appropriate monomers that can polymerize only by the action of initiators. Recently one example of chain-growth supramolecular polymerization with “living” characteristics is demonstrated. In this case, a bowl-shaped monomer with amide-appended side chains form a kinetically favored intramolecular hydrogen bonding network and does not spontaneously undergo supramolecular polymerization at ambient temperatures. However, an N-methylated version of the monomer serves as an initiator by opening the intramolecular hydrogen bonding network for the supramolecular polymerization, just like ring-opening covalent polymerization.
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The isolation of monomeric molecular hydrides usually require extremely mild conditions, which are partial pressure and cryogenic temperature. The reason for this is threefold - firstly, most molecular hydrides are thermodynamically unstable toward decomposition into their elements; secondly, many molecular hydrides are also thermodynamically unstable toward polymerisation; and thirdly, most molecular hydrides are also kinetically unstable toward these types of reactions due to low activation energy barriers. Instability toward decomposition is generally attributable to poor contribution from the orbitals of the heavier elements to the molecular bonding orbitals. Instability toward polymerisation is a consequence of the electron-deficiency of the monomers relative to the polymers.
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In 2011, the European Medicines Agency approved Tafamidis or Vyndaqel for the amelioration of FAP. Vyndaqel kinetically stabilizes the TTR tetramer, preventing tetramer dissociation required for TTR amyloidogenesis and degradation of the autonomic nervous system and/or the peripheral nervous system and/or the heart. TTR is also thought to have beneficial side effects, by binding to the infamous beta- amyloid protein, thereby preventing beta-amyloid's natural tendency to accumulate into the plaques associated with the early stages of Alzheimer's disease. Preventing plaque formation is thought to enable a cell to rid itself of this otherwise toxic protein form and, thus, help prevent and maybe even treat the disease.
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He was able to share/steal speed, use his speed to kinetically upgrade his attacks, and super heal others. Writer Mark Waid expanded on the character's powers thematically and further redefined the character by introducing the Speed Force, an energy source that served as a pseudo-scientific explanation for his powers and that of other fictional speedsters within the DC Universe. Using this concept as a basis, the character's ability to tap into the Speed Force was used to expand his abilities. The character was now able to lend speed to other objects and people and create a costume directly out of Speed Force energy.
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Tolman's work in the bioinorganic field focuses on Cu-O adducts, specifically copper proteins whose diverse, biological functions include: O2 transport, aromatic ring oxidations, biogenesis of hormones. His work studies the potential of 1:1 Cu/O2 adducts as catalytic species, which have been known as transient intermediates for more commonly studied 2:1 and even 3:1 Cu/O2 molecules. These complexes, while kinetically favored in formation are thermodynamically unstable due to negative entropy values, thus making them more difficult to isolate. Although, increasing ligand sizes on these 1:1 adducts did correlate with slower reaction rate constants; advantageous for isolating and studying these complexes.
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In his review for AllMusic, Thom Jurek states " As a whole, Piano Sutras is instructive; it showcases Shipp's musical dialogue with the listener as evolutionary. It offers an incremental glimpses into his process of discovery and evidence of his mastery when kinetically applying his finely tuned sense of hearing." The Down Beat review by Daniel A. Brown describes the album as "a 13-track collection of pieces that are in turn meditative and aggressive, at times in the same song" and says that "also further reveals Shipp’s mastery of dynamic playing, his awareness of both the timbral limits and sonic possibilities of the piano."Brown, Daniel A. Piano Sutras review.
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He used the technique to open and close a set of DNA tweezers made of two DNA helices using an auxiliary strand of DNA as fuel . Since its first use, the technique has been modified for the construction of autonomous molecular motors, catalytic amplifiers, reprogrammable DNA nanostructures and molecular logic gates . It has also been used in conjunction with RNA for the production of kinetically-controlled ribosensors . TMSD starts with a double- stranded DNA complex composed of the original strand and the protector strand . The original strand has an overhanging region the so-called “toehold” which is complementary to a third strand of DNA referred to as the “invading strand”.
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Intramolecular thiol-ene reactions provide a means to create sulphur- containing heterocycles. The radical-initiated thiol-ene reaction has enabled the successful synthesis of four- to eight-membered rings, as well as macrocycles. While the radical thiol-ene reaction favors the anti-Markovnikov product, the regiochemistry of the cycloaddition depends on substituent effects and reaction conditions, which serve to direct the cyclization towards the thermodynamically or kinetically favored product respectively. This section examines intramolecular thiol-ene cyclization reactions, which yields a mixture of 5-exo and 6-endo products in order to facilitate a discussion of the factors, which may affect the regioselectivity of the intramolecular addition.
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Ligands with a high trans effect are in general those with high π acidity (as in the case of phosphines) or low-ligand lone-pair–dπ repulsions (as in the case of hydride), which prefer the more π-basic equatorial sites in the intermediate. The second equatorial position is occupied by the incoming ligand; due to the principle of microscopic reversibility, the departing ligand must also leave from an equatorial position. The third and final equatorial site is occupied by the trans ligand, so the net result is that the kinetically favored product is the one in which the ligand trans to the one with the largest trans effect is eliminated.
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Laser In Front, Grunts In Back: Boeing Offers Anti-Aircraft Vehicles - Breakingdefense.com, 2 August 2017 In October 2017, BAE displayed an updated version of the Bradley Linebacker called the M-SHORAD (Mobile Short-Range Air Defense) equipped with the pMHR search radar mounted around the turret, a fire-control radar, a jammer on top of the turret to non-kinetically defeat unmanned aerial vehicles (UAVs), the main gun replaced with an XM914 30 mm autocannon with airburst rounds, and a missile launcher that could accommodate various missiles including the Stinger, AIM-9X Sidewinder, or others.BAE Turns Bradley Into MiG-Killer - Breakingdefense.com, 10 October 2017Everything’s coming up SHORAD - Defensenews.
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Mechanistic studies have focused on unstabilized ylides, because the intermediates can be followed by NMR spectroscopy. The existence and interconversion of the betaine (3a and 3b) is subject of ongoing research. For lithium-free Wittig reactions, most recent studies support a concerted formation of the oxaphosphetane without intervention of a betaine. In particular, phosphonium ylides 1 react with carbonyl compounds 2 via a [2+2] cycloaddition that is sometimes described as having [π2s+π2a] topology to directly form the oxaphosphetanes 4a and 4b. Under lithium-free conditions, the stereochemistry of the product 5 is due to the kinetically controlled addition of the ylide 1 to the carbonyl 2.
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He also won the most prize money. His performance of Prokofiev's Piano Concerto No. 3 (Op. 26) with the Fort Worth Symphony Orchestra and James Conlon in the final round was described by Scott Cantrell of The Dallas Morning News as "kinetically dramatic, almost savage in some of its more forceful passages but lovingly caressed in its more lyric moments", while the Pittsburgh Post-Gazette described it as "the most spectacular moment of the week". Pompa-Baldi has appeared at such venues as Carnegie Hall and Alice Tully Hall in New York, Cleveland's Severance Hall, Paris' Salle Pleyel, Milan's Sala Verdi, Shanghai's Grand Theatre, and Boston's Symphony Hall.
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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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In the atmosphere, the suspended particles are called particulates and consist of fine dust and soot particles, sea salt, biogenic and volcanogenic sulfates, nitrates, and cloud droplets. Suspensions are classified on the basis of the dispersed phase and the dispersion medium, where the former is essentially solid while the latter may either be a solid, a liquid, or a gas. In modern chemical process industries, high-shear mixing technology has been used to create many novel suspensions. Suspensions are unstable from a thermodynamic point of view but can be kinetically stable over a longer period of time, which in turn can determine a suspension's shelf life.
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But a student learning Turkish music in the traditional meşk system first memorizes the usul kinetically by striking the knees with the hands. The student then sings the vocal or instrumental composition while performing the underlying usul. This pedagogical system helps the student memorize the composition while internalizing the underlying rhythmic structure. Usul patterns have standard pronounceable vocables built from combinations of the syllables düm, dü-üm, tek, tekkyaa, teke, te-ek, where düm, dü-üm indicate a strong low beat of single or double duration, and tek, tekkya, teke, te-ek indicate various combinations of light beats of half, single or double duration.
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An advantage of flow reactors is that high-pressure tubing can be utilized for hydrogenation and other hyperbaric reactions. Because the head space of a batch reactor is eliminated, however, many of the safety concerns associated with running high-pressure reactions are obviated by the use of a continuous process reactor. Additionally, a two-stage mixed suspension-mixed product removal (MSMPR) module was designed for the scalable, continuous, kinetically controlled crystallization of the product, so it was possible to isolate in >99 percent ee, eliminating the need for an additional batch crystallization step. This continuous process afforded 144 kg of the key intermediate in 86 percent yield, comparable with a 90 percent isolated yield using the batch process.
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During a launch, the induction motor requires a large surge of electric power that exceeds what the ship's own continuous power source can provide. The EMALS energy-storage system design accommodates this by drawing power from the ship during its 45-second recharge period and storing the energy kinetically using the rotors of four disk alternators; the system then releases that energy (up to 484 MJ) in 2–3 seconds. Each rotor delivers up to (approximately one gasoline gallon equivalent) and can be recharged within 45 seconds of a launch; this is faster than steam catapults. A maximum-performance launch using 121 MJ of energy from each disk alternator slows the rotors from 6400 rpm to 5205 rpm.
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The greater the overlap, the quicker the molecule can undergo transition from the higher to the lower level. Overlap between pairs is greatest when the two vibrational levels are close in energy; this tends to be the case when the vibrationless levels of the electronic states coupled by the transition (where the vibrational quantum number v is zero) are close. In most molecules, the vibrationless levels of the excited states all lie close together, so molecules in upper states quickly reach the lowest excited state, S1, before they have time to fluoresce. However, the energy gap between S1 and S0 is greater, so here fluorescence occurs, since it is now kinetically competitive with internal conversion (IC).
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The poly-leucine strands demonstrate enzyme-like kinetics with a first-order dependence on and eventual saturation with both the hydroperoxide anion (KM= 30 mM) and the olefin substrate (KM=110 mM.) Kinetic study suggests that the reaction proceeds by random steady-state formation of a ternary (polyleucine+hydroperoxide anion+olefin) complex. Both substrates must bind prior to reaction, and while either may bind first, initial hydroperoxide binding is kinetically preferred. The rapid equilibrium enabling complex formation is followed by the rate- limiting formation of the peroxide enolate (Figure 3).Carrea, G.; Colonna, S.; Meek, A. D.; Ottolina, G.; Roberts, S. M., "Kinetics of chalcone oxidation by peroxide anion catalysed by poly-L-leucine". Chem. Comm.
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Maddin was commissioned by The Power Plant gallery in Toronto and, in an installation curated by Philip Monk, produced a series of ten short films. The exhibition premiered at the 42nd International Film Festival Rotterdam from January 22 to February 2, 2003, where the catalogue described it as "A firstofitskind, tenpart peephole installation jampacked with enough kinetically photographed action to seem like a neverending cliffhanger." Each six-minute film is viewed through a peephole and together present a fictionalised autobiography, whose main character (named "Guy Maddin") is embroiled in illegal abortion, murderous intrigue, sexual rivalry, and hockey. The installation was also exhibited at The Power Plant Contemporary Art Gallery in Toronto from March 22 to May 25, 2003.
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The enzymatic reaction that trypsin catalyzes is thermodynamically favorable, but requires significant activation energy (it is "kinetically unfavorable"). In addition, trypsin contains an "oxyanion hole" formed by the backbone amide hydrogen atoms of Gly-193 and Ser-195, which through hydrogen bonding stabilize the negative charge which accumulates on the amide oxygen after nucleophilic attack on the planar amide carbon by the serine oxygen causes that carbon to assume a tetrahedral geometry. Such stabilisation of this tetrahedral intermediate helps to reduce the energy barrier of its formation and is concomitant with a lowering of the free energy of the transition state. Preferential binding of the transition state is a key feature of enzyme chemistry.
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It has been shownAbsence of SN1 Involvement in the Solvolysis of Secondary Alkyl Compounds, T. J. Murphy, J. Chem. Educ.; 2009; 86(4) pp 519-24; (Article) doi: 10.1021/ed041p678 that except in uncommon (but predictable cases) primary and secondary substrates go exclusively by the SN2 mechanism while tertiary substrates go via the SN1 reaction. There are two factors which complicate determining the mechanism of nucleophilic substitution reactions at secondary carbons: 1) Many reactions studied are solvolysis reactions where a solvent molecule–often an alcohol, is the nucleophile. While still a second order reaction mechanistically, the reaction is kinetically first order as the concentration of the nucleophile–the solvent molecule, is effectively constant during the reaction.
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It is important to note that even while kinetic analysis is a powerful tool for determining the stoichiometry of the turn-over limiting transition state relative to the ground state, it cannot answer all mechanistic questions. It is possible for two mechanisms to be kinetically indistinguishable, especially under catalytic conditions. For any thorough mechanistic evaluation it is necessary to conduct kinetic analysis of both the catalytic process and its individual steps (when possible) in concert with other forms of analysis such as evaluation of linear free energy relationships, isotope effect studies, computational analysis, or any number of alternative approaches. Finally, it is important to note that no mechanistic hypothesis can ever be proven; alternative mechanistic hypothesis can only be disproven.
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Four isozymes of pyruvate kinase expressed in vertebrates: L (liver), R (erythrocytes), M1 (muscle and brain) and M2 (early fetal tissue and most adult tissues). The L and R isozymes are expressed from the gene PKLR, whereas the M1 and M2 isozymes are expressed from the gene PKM2. The R and L isozymes differ from M1 and M2 in that they are allosterically regulated. Kinetically, the R and L isozymes of pyruvate kinase have two distinct conformation states; one with a high substrate affinity and one with a low substrate affinity. The R-state, characterized by high substrate affinity, serves as the activated form of pyruvate kinase and is stabilized by PEP and fructose 1,6-bisphosphate (FBP), promoting the glycolytic pathway.
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Audiences polled by PostTrak gave the film an average 3 out of 5 stars, with 45% saying they would definitely recommend it. Owen Gleiberman of Variety wrote: "Bloodshot is a trash compactor of a comic-book film, but it's smart trash, an action matrix that’s fun to plug into." Justin Lowe of The Hollywood Reporter gave the film a mixed reviews but was positive about the director saying "Wilson acquits himself adequately enough, emphasizing pacing over character development, but delivering a series of kinetically propelled scenes that clearly benefit from his extensive visual effects experience." Richard Roeper of the Chicago Sun- Times gave the film 2 out of 4 stars, calling it ambitious but "intermittently entertaining" and "frantically overcooked, bursting with headache-inducing, rapid-cut action sequences".
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Thus, in the presence of the inhibitor, the enzyme's effective Km and Vmax become (α/α')Km and (1/α')Vmax, respectively. However, the modified Michaelis-Menten equation assumes that binding of the inhibitor to the enzyme has reached equilibrium, which may be a very slow process for inhibitors with sub- nanomolar dissociation constants. In these cases, it is usually more practical to treat the tight-binding inhibitor as an irreversible inhibitor (see below); however, it can still be possible to estimate Ki' kinetically if Ki is measured independently. The effects of different types of reversible enzyme inhibitors on enzymatic activity can be visualized using graphical representations of the Michaelis–Menten equation, such as Lineweaver–Burk and Eadie-Hofstee plots.
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Dr. Jae-Kap Lee discovered the new crystalline form of graphite in 2008 when he grew graphite onto diamond. He realized that graphene layers comprising graphite grew on diamond (111) plane with stacked in the sequence of AA', due to the crystallographic feature of diamond. The non-Bernal AA’ allotrope of graphite is synthesized by the thermal- and plasma-treatment of graphene nanopowders at ~1,500 °C. The formation of AA’ bilayer graphene nuclei facilitates the preferred texture growth and results in single-crystal AA’ graphite in the form of nanoribbons (1D) or microplates (2D) of a few nm in thickness. Kinetically controlled AA’ graphite exhibits unique nano- and single- crystalline feature and shows quasi-linear behavior near the K-point of the electronic band structure resulting in anomalous optical and acoustic phonon behavior (Fig. 3).
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PmPV1 is an orthologous of ovorubin and scalarin, sharing most of the structural features with the former protein and cross-reacting with anti-ovorubin polyclonal antibodies. Like ovorubin and scalarin, PmPV1 is highly glycosylated (~13% w/w) and carries carotenoid pigments, indicating that this perivitellin would probably have the antioxidant, photoprotective, aposematic and water retention functions described for its orthologous. PmPV1 is a kinetically stable protein that, like most other studied perivitellins from Pomacea snails, is highly stable in a wide range of pH values and withstands gastrointestinal digestion, characteristics associated with an antinutritive defense system that deters predation by lowering the nutritional value of the eggs. Remarkably, and in agreement with this antinutritive activity, PmPV1 withstands in vivo digestion, being recovered structurally unaltered from mice feces after trespassing the whole digestive system.
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Sigma, real name Siebren de Kuiper, is a Dutch astrophysicist associated with Talon. His main weapons are Hyperspheres, gravitic projectiles that can bounce off walls and damage a small area that draw foes into the explosion, and Accretion, which gathers debris into a large projectile to kinetically throw at opponents, causing knockback. He also has two defensive abilities: Experimental Barrier, a shield that he can extend out in front of him to a variable distance and then recall it, upon which it starts regenerating any damage taken; and Kinetic Grasp, which creates a field that absorbs projectiles that hit it which, upon release, coverts that into temporary shields for the character. His ultimate, Gravitic Flux, allows him to fly up briefly to place a black hole on the ground.
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Compounds that have a monocyclic, planar conjugated system containing (4n + 2) π-electrons for whole numbers n are aromatic and exhibit an unusual stability. The classic example benzene has a system of six π electrons, which, together with the planar ring of C–C σ bonds containing 12 electrons and radial C–H σ bonds containing six electrons, forms the thermodynamically and kinetically stable benzene ring, the common core of the benzenoid aromatic compounds. For benzene itself, there are two equivalent conjugated contributing Lewis structures (the so-called Kekulé structures) that predominate.While the two Kekulé resonance forms contribute to most (>90%) of the π bond energy, there are also a number of other minor contributors to the wavefunction in the valence bond treatment, including the three Dewar resonance forms, and even smaller contributions from various ionic and singlet diradical forms.
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They encounter a figure in clockwork armor, who is revealed to be another version of Patrick, from 2001, who traveled forward in time to recover his initial machine from the Men of the Machine; they, however, go separate ways, hoping to stop Gordon. At the penthouse the Patrick in the clockwork armor disrupts the meeting: a cat, whose soul had been transferred with that of a shark, gets loose, and the shark's soul psycho-kinetically attacks everyone present, killing the present Patrick and some of Gordon's cult. As Dirk, Todd, and the armored Patrick flee the hotel, Todd recognizes the conversation he had seen himself in previously. Later they encounter an earlier version of Dirk, and the present version provides his earlier self with cryptic clues to direct him to meet with Todd and solve the case.
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Phosphaalkynes with small substituents (H, F, Me, Ph, ect.) undergo decomposition at or below room temperature by way of polymerization/oligimerization to yield mixtures of products which are challenging to characterize. The same is largely true of kinetically stable phosphaalkynes, which undergo oligimerization reactions at elevated temperature. In spite of the challenges associated with isolating and identifying the products of these oligimerizations, however, cuboidal tetramers of tert-butylphosphaalkyne and tert-pentylphosphaalkyne have been isolated (albeit in low yield) and identified following heating of the respective phosphaalkyne. Computational chemistry has proved a valuable tool for studying these synthetically complex reactions, and it has been shown that while the formation of phosphaalkyne dimers is thermodynamically favorable, the formation of trimers, tetramers, and higher order oligomeric species tends to be more favorable, accounting for the generation of intractable mixtures upon inducing oligomerization of phosphaalkynes experimentally.
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This release of neurotransmitters occurs in two kinetically distinct phases: a small fast pool where about twenty percent of the total is released in about 1 millisecond, and a large sustained pool where the remaining components are released over hundreds of milliseconds. The existence of correspondence between the pool of tethered vesicles and the pool for sustained release in the rods and bipolar cells of the ribbon reveals that the ribbon may serve as a platform where the vesicles can be primed to allow sustained release of neurotransmitters. This large size of the sustained large component is what separates the ribbon synapse active zones from those of conventional neurons where sustained release is small in comparison. Once the presynaptic vesicles have been depleted, the bipolar cell's releasable pool requires several seconds to refill with the help of ATP hydrolysis.
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Monomers undergoing supramolecular polymerization are considered to be in equilibrium with the growing polymers, and thermodynamic factors therefore dominate the system. However, when the constituent monomers are connected via strong and multivalent interactions, a “metastable” kinetic state can dominate the polymerization. An externally supplied energy, in the form of heat in most cases, can transform the “metastable” state into a thermodynamically stable polymer. A clear understanding of multiple pathways exist in supramolecular polymerization is still under debate, however, the concept of “pathway complexity”, introduced by E.W. “Bert” Meijer, shed a light on the kinetic behavior of supramolecular polymerization. Thereafter, many dedicated scientists are expanding the scope of “pathway complexity” because it can produce a variety of interesting assembled structures from the same monomeric units. Along this line of kinetically controlled processes, supramolecular polymers having “stimuli-responsive” and “thermally bisignate” characteristics is also possible.
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He predicted the existence of krypton hexafluoride () and xenon hexafluoride (), speculated that might exist as an unstable compound, and suggested that xenic acid could form perxenate salts. These predictions were shown to be generally accurate, except that is now thought to be both thermodynamically and kinetically unstable. Xenon compounds are the most numerous of the noble gas compounds that have been formed. Most of them have the xenon atom in the oxidation state of +2, +4, +6, or +8 bonded to highly electronegative atoms such as fluorine or oxygen, as in xenon difluoride (), xenon tetrafluoride (), xenon hexafluoride (), xenon tetroxide (), and sodium perxenate (). Xenon reacts with fluorine to form numerous xenon fluorides according to the following equations: ::Xe + F2 → XeF2 ::Xe + 2F2 → XeF4 ::Xe + 3F2 → XeF6 Some of these compounds have found use in chemical synthesis as oxidizing agents; , in particular, is commercially available and can be used as a fluorinating agent.
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The discoverer of the inner sphere mechanism was Henry Taube, who was awarded the Nobel Prize in Chemistry in 1983 for his pioneering studies. A particularly historic finding is summarized in the abstract of the seminal publication. > "When Co(NH3)5Cl++ is reduced by Cr++ in M [meaning 1 M] HClO4, 1 Cl− > appears attached to Cr for each Cr(III) which is formed or Co(III) reduced. > When the reaction is carried on in a medium containing radioactive Cl, the > mixing of the Cl− attached to Cr(III) with that in solution is less than > 0.5%. This experiment shows that transfer of Cl to the reducing agent from > the oxidizing agent is direct…" The paper and the excerpt above can be described with the following equation: :[CoCl(NH3)5]2+ \+ [Cr(H2O)6]2+ → [Co(NH3)5(H2O)]2+ \+ [CrCl(H2O)5]2+ The point of interest is that the chloride that was originally bonded to the cobalt, the oxidant, becomes bonded to chromium, which in its +3 oxidation state, forms kinetically inert bonds to its ligands.
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He is first requested by Helmer when arriving on Miltia with M.O.M.O. to obtain reconnaissance information from a brief conversation with Albedo via a telepathic link in order to gain insight into Albedo's plans for the future tense, the two converse with Gaignun offering to come to terms with Albedo at the time but Albedo was only interested in goading his brother and even goes as far as calling him two-faced when Gaignun kinetically destroyed Albedo's right arm at one point during the conversation when Albedo had threatened Rubedo's life. Later on flashbacks occur when the main team take subconscious dives into Sakura Mizrahi's mind in order to allow her to speak once again. These adventures showed the rift growing between the trio of U.R.T.V. units, which eventually led to a breakdown during the Miltian Conflict, causing Albedo to come into contact with U-DO and become insane. At the end of Episode II, Gaignun suffers from a double personality; one part is Gaignun, the other is Dimitri Yuriev, his father.
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