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A system's internal state of thermodynamic equilibrium should be distinguished from a "stationary state" in which thermodynamic parameters are unchanging in time but the system is not isolated, so that there are, into and out of the system, non-zero macroscopic fluxes which are constant in time.
Non-equilibrium thermod... | 7 | Physical Chemistry |
In chemistry, the dispersity is a measure of the heterogeneity of sizes of molecules or particles in a mixture. A collection of objects is called uniform if the objects have the same size, shape, or mass. A sample of objects that have an inconsistent size, shape and mass distribution is called non-uniform. The objects ... | 7 | Physical Chemistry |
In molecular biology, an arginine finger is an amino acid residue of some enzymes. Arginine fingers are often found in the protein superfamily of AAA+ ATPases, GTPases, and dUTPases, where they assist in the catalysis of the gamma phosphate or gamma and beta phosphates from ATP or GTP, which creates a release of energy... | 1 | Biochemistry |
Usually when describing a space geometrically, a coordinate system is used which consists of a choice of origin and a basis of linearly independent, non-coplanar basis vectors , where is the dimension of the space being described. With reference to this coordinate system, each point in the space can be specified by ... | 3 | Analytical Chemistry |
The systematic names sulfanediide and sulfide(2−), valid IUPAC names, are determined according to the substitutive and additive nomenclatures, respectively. However, the name sulfide is also used in compositional IUPAC nomenclature which does not take the nature of bonding involved. Examples of such naming include sele... | 0 | Organic Chemistry |
With credit to the previously listed techniques, biomarkers were found in petroleum and source rock extract. These are fossils from organisms, but are closer in size to molecules than to visible hand samples. They display the same structure as their parent biomolecules and are used in the identification of the organic ... | 9 | Geochemistry |
The flux method is a crystal growth method where starting materials are dissolved in a solvent (flux), and are precipitated out to form crystals of a desired compound. The flux lowers the melting point of the desired compound, analogous to a wet chemistry recrystallization. The flux is molten in a highly stable crucibl... | 3 | Analytical Chemistry |
Glycoinformatics is a field of bioinformatics that pertains to the study of carbohydrates involved in protein post-translational modification. It broadly includes (but is not restricted to) database, software, and algorithm development for the study of carbohydrate structures, glycoconjugates, enzymatic carbohydrate sy... | 0 | Organic Chemistry |
The chemical model consists of a set of chemical species present in solution, both the reactants added to the reaction mixture and the complex species formed from them. Denoting the reactants by A, B..., each complex species is specified by the stoichiometric coefficients that relate the particular combination of react... | 7 | Physical Chemistry |
If the thermodynamic operation is entire removal of walls, then extensive state variables of the composed system are the respective sums of those of the component systems. This is called the additivity of extensive variables. | 7 | Physical Chemistry |
NSAIDs such as ibuprofen work by inhibiting the cyclooxygenase (COX) enzymes, which convert arachidonic acid to prostaglandin H (PGH). PGH, in turn, is converted by other enzymes to several other prostaglandins (which are mediators of pain, inflammation, and fever) and to thromboxane A (which stimulates platelet aggreg... | 4 | Stereochemistry |
The ECW model created by Russell S. Drago is a quantitative model that describes and predicts the strength of Lewis acid base interactions, . The model assigned and parameters to many Lewis acids and bases. Each acid is characterized by an and a . Each base is likewise characterized by its own and . The and param... | 7 | Physical Chemistry |
The IX Brigade, led by Okladnikov, worked in the Greater Balkan region of Turkmenistan, and in the plateau of Krasnovodsk. The finds at the Jebel rock shelter site near the Caspian Sea on the southwestern end of the Uly Balkan massif was a stratigraphic sequence of Mesolithic and Neolithic deposits, considered a model ... | 8 | Metallurgy |
In general, most hydroamination catalysts require elevated temperatures to function efficiently, and as such, only the thermodynamic product is observed. The isolation and characterization of the rarer and more synthetically valuable kinetic allyl amine product was reported when allenes was used at the unsaturated subs... | 0 | Organic Chemistry |
The human hNanog protein coded by the NANOG gene, consists of 305 amino acids and possesses 3 functional domains: the N-terminal domain, the C- terminal domain, and the conserved homeodomain motif. The homeodomain region facilitates DNA binding. The NANOG is located on chromosome 12, and the mRNA contains a 915 bp open... | 1 | Biochemistry |
Escape and radiate coevolution is a hypothesis proposing that a coevolutionary arms-race between primary producers and their consumers contributes to the diversification of species by accelerating speciation rates. The hypothesized process involves the evolution of novel defenses in the host, allowing it to "escape" an... | 1 | Biochemistry |
The TGF-β pathway regulates many cellular processes in developing embryo and adult organisms, including cell growth, differentiation, apoptosis, and homeostasis. There are five kinds of type II receptors and seven types of type I receptors in humans and other mammals. These receptors are known as "dual-specificity kina... | 1 | Biochemistry |
Chemotronics is an intersection field of chemistry (especially electrochemistry) and electronics dealing with the design of electrochemical and optical chemical sensors. One of pioneers of this field was Alexander Frumkin. | 3 | Analytical Chemistry |
Rust removal from small iron or steel objects by electrolysis can be done in a home workshop using simple materials such as a plastic bucket filled with an electrolyte consisting of washing soda dissolved in tap water, a length of rebar suspended vertically in the solution to act as an anode, another laid across the to... | 8 | Metallurgy |
The term photoprotein was first used to describe the unusual chemistry of the luminescent system of Chaetopterus (a marine Polychaete worm). This was meant to distinguish them from other light-producing proteins because these do not exhibit the usual luciferin-luciferase reaction. | 1 | Biochemistry |
Tautomers are structural isomers which readily interconvert, so that two or more species co-exist in equilibrium such as
Important examples are keto-enol tautomerism and the equilibrium between neutral and zwitterionic forms of an amino acid. | 4 | Stereochemistry |
STAT3 is a member of the STAT protein family. In response to cytokines and growth factors, STAT3 is phosphorylated by receptor-associated Janus kinases (JAK), forms homo- or heterodimers, and translocates to the cell nucleus where it acts as a transcription activator. Specifically, STAT3 becomes activated after phospho... | 1 | Biochemistry |
In atomic, molecular, and optical physics, a magneto-optical trap (MOT) is an apparatus which uses laser cooling and a spatially-varying magnetic field to create a trap which can produce samples of cold, neutral atoms. Temperatures achieved in a MOT can be as low as several microkelvin, depending on the atomic species,... | 7 | Physical Chemistry |
Ketene is produced on a commercial scale by thermal dehydration of acetic acid. Substituted ketenes can be prepared from acyl chlorides by an elimination reaction in which HCl is lost:
In this reaction, a base, usually triethylamine, removes the acidic proton alpha to the carbonyl group, inducing the formation of the c... | 0 | Organic Chemistry |
In 2009 the Chesapeake Bay Foundation (CBF) filed suit against EPA for its failure to finalize a total maximum daily load (TMDL) ruling for the bay, pursuant to the Clean Water Act. The TMDL would restrict water pollution from farms, land development, power plants and sewage treatment plants. EPA, which had been workin... | 2 | Environmental Chemistry |
Polyurea and polyurethane are copolymers used in the manufacture of spandex, which was invented in 1959.
Polyurea was originally developed in automotive applications in the 1980s but other applications such as protecting tabletop edges followed. Its fast reactivity and relative moisture insensitivity made it useful for... | 7 | Physical Chemistry |
This form factor is useful for any application where the spectrum analyzer needs to be very light and small. Handheld analyzers usually offer a limited capability relative to larger systems. Attributes that contribute to a useful handheld spectrum analyzer include:
*Very low power consumption.
*Battery-powered operatio... | 7 | Physical Chemistry |
Initial treatment can involve placing the object in a desiccating environment. Deprived of water, the reaction cannot continue. However, re-exposure of the object to even atmospheric water can restart the process. Bronze disease remains an active area of research within object conservation. | 8 | Metallurgy |
*ANXA6
*ANXA7
*ARPC1A Actin-related peptide
*ARPC2
*ARPC5L
*CAPZA2
*CAPZB
*RHOA also implicated in regulation of cell cycle
*RHOB
*RHOT1 mitochondrial trafficking
*RHOT2
*TUBB Tubulin, beta polypeptide
*WDR1 actin disassembly? | 1 | Biochemistry |
The N-Acetylglucosamine (GlcNAc) receptor has been recently found to interact and bind with vimentins at the cell surface. Research indicates that the GlcNAc receptor can therefore be used to target vimentin-expressing cells for gene delivery via receptor-mediated endocytosis. | 1 | Biochemistry |
Viral genes are expressed through the use of the host cells replication machinery; therefore, many viral genes have promoters that support binding of many transcription factors found naturally in the host cells. These transcription factors along with the virus own proteins can repress or activate genes from both the v... | 1 | Biochemistry |
The most economical source of carbon for recycling into fuel is flue-gas emissions from fossil-fuel combustion where it can be obtained for about US$7.50 per ton. However, this is not carbon-neutral, since the carbon is of fossil origin, therefore moving carbon from the geosphere to the atmosphere. Since carbonic acid ... | 0 | Organic Chemistry |
Zircon (ZrSiO) is commonly found in felsic igneous rock. Because both Ce and Ce can substitute for zirconium, Zircon often has a positive Ce anomaly. Ce substitutes with Zr much more easily than Ce because Ce (ionic radius 0.97Å) has the same charge and a similar ionic radius as Zr (ionic radius 0.84Å). Therefore, the ... | 9 | Geochemistry |
Linear PPA is produced by anionic polymerization methods using a strong nucleophile as an initiator. This technique prevents the cyclization of the polymer chain as the propagating species have only one charged terminus that cannot backbite the other terminus which, in turn, is neutral in charge. Although processing li... | 7 | Physical Chemistry |
Base-promoted epoxide isomerization is the conversion of alkyl epoxides to ring-opened products through the action of strong base. Isomerizations of this type are most often used to synthesize allylic alcohols, although other products are possible. | 0 | Organic Chemistry |
Some trace fossils can be used as local index fossils, to date the rocks in which they are found, such as the burrow Arenicolites franconicus which occurs only in a layer of the Triassic Muschelkalk epoch, throughout wide areas in southern Germany.
The base of the Cambrian period is defined by the first appearance of ... | 2 | Environmental Chemistry |
Accurate determination of core temperature often requires a special low temperature thermometer, as most clinical thermometers do not measure accurately below . A low temperature thermometer can be placed in the rectum, esophagus or bladder. Esophageal measurements are the most accurate and are recommended once a perso... | 1 | Biochemistry |
Capnellene derivatives have recently been identified as possible treatments for neuropathic pain. Neuropathic pain is characterized by damage to peripheral or central nerves that results in pathological nociceptive transmission, the neuronal process that responds noxious stimuli. Two capnellene derivatives Δ-capnellene... | 0 | Organic Chemistry |
Men have a V̇O max that is 26% higher (6.6 mL/(kg·min)) than women for treadmill and 37.9% higher (7.6 mL/(kg·min)) than women for cycle ergometer on average. V̇O max is on average 22% higher (4.5 mL/(kg·min)) when measured using a cycle ergometer compared with a treadmill. | 1 | Biochemistry |
In general, enols are less stable than their keto equivalents because of the favorability of the C=O double bond over C=C double bond. However, enols can be stabilized kinetically or thermodynamically.
Some enols are sufficiently stabilized kinetically so that they can be characterized.
Delocalization can stabilize the... | 0 | Organic Chemistry |
*Acetyl-CoA
*fatty acyl-CoA (activated form of all fatty acids; only the CoA esters are substrates for important reactions such as mono-, di-, and triacylglycerol synthesis, carnitine palmitoyl transferase, and cholesterol esterification)
**Propionyl-CoA
**Butyryl-CoA
**Myristoyl-CoA
**Crotonyl-CoA
*Acetoacetyl-CoA
*Co... | 1 | Biochemistry |
Symmetries in nature lead directly to conservation laws, something which is precisely formulated by Noether's theorem.
The basic idea of time-translation symmetry is that a translation in time has no effect on physical laws, i.e. that the laws of nature that apply today were the same in the past and will be the same in... | 3 | Analytical Chemistry |
Due to it being a lesser understood post-translational modification, arginylation and its regulation in vivo still remains largely esoteric. The expression of ATE1 can vary significantly within different tissues, but its levels within these tissues peak at mid-development but begin to decline as an organism ages. It ha... | 1 | Biochemistry |
Spegatrine is an α- and α-adrenergic receptor antagonist isolated from Rauvolfia verticillata. Its dimer dispegatrine has greater antagonist affinity for α-adrenergic receptors. | 0 | Organic Chemistry |
Mutations in this gene are associated with glycogen storage disease type IV (also known as Andersen's disease) in newborns and with adult polyglucosan body disease.
Approximately 40 mutations in the GBE1 gene, most resulting in a point mutation in the glycogen branching enzyme, have led to the early childhood disorder,... | 1 | Biochemistry |
Tarnish is a product of a chemical reaction between a metal and a nonmetal compound, especially oxygen and sulfur dioxide. It is usually a metal oxide, the product of oxidation; sometimes it is a metal sulfide. The metal oxide sometimes reacts with water to make the hydroxide, or with carbon dioxide to make the carbona... | 8 | Metallurgy |
Mostly, SIRs have been investigated and used for the recovery of heavy metals. Applications include the removal of cadmium, vanadium, copper, chrome, iridium, etc. | 3 | Analytical Chemistry |
In cooperation with the chemical company BASF, Ralf Reski and coworkers established a collection of knockout mosses to use for gene identification. | 1 | Biochemistry |
Keesom forces, also known as dipole–dipole interactions, result from two molecules that have permanent dipoles due to electronegativity differences between atoms in the molecule. This dipole causes a coulombic attraction between the two molecules. | 6 | Supramolecular Chemistry |
In organic chemistry, a lactol is a functional group which is the cyclic equivalent of a hemiacetal () or a hemiketal ().
The compound is formed by the intramolecular, nucleophilic addition of a hydroxyl group () to the carbonyl group () of an aldehyde () or a ketone ().
A lactol is often found as an equilibrium mixtur... | 0 | Organic Chemistry |
The KRAB domain had initially been identified in 1988 as a periodic array of leucine residues separated by six amino acids 5’ to the zinc finger region of KOX1/ZNF10 coined heptad repeat of leucines (also known as a leucine zipper). Later, this domain was named in association with the C2H2-Zinc finger proteins Krüppel... | 1 | Biochemistry |
The electron transport chain of green sulfur bacteria—such as is present in the model organism Chlorobaculum tepidum—uses the reaction center bacteriochlorophyll pair, P840. When light is absorbed by the reaction center, P840 enters an excited state with a large negative reduction potential, and so readily donates the ... | 5 | Photochemistry |
In terms of molecular structure, one distinguishes first between low-molecular-weight (LMW) and high-molecular-weight (HMW) products. The generally accepted threshold between LMW and HMW is a molecular weight of about 700. LMW fine chemicals, also designated as small molecules, are produced by traditional chemical synt... | 0 | Organic Chemistry |
The SKP technique is based on parallel plate capacitor experiments performed by Lord Kelvin in 1898. In the 1930s William Zisman built upon Lord Kelvin's experiments to develop a technique to measure contact potential differences of dissimilar metals. | 7 | Physical Chemistry |
High concentrations of aldehydes tend to be very pungent and overwhelming, but low concentrations can evoke a wide range of aromas.
* Acetaldehyde (ethereal)
* Hexanal (green, grassy)
* cis-3-Hexenal (green tomatoes)
* Furfural (burnt oats)
* Hexyl cinnamaldehyde
* Isovaleraldehyde – nutty, fruity, cocoa-like
* Anisic ... | 0 | Organic Chemistry |
For an infinite two-dimensional lattice, defined by its primitive vectors , its reciprocal lattice can be determined by generating its two reciprocal primitive vectors, through the following formulae,
where is an integer and
Here represents a 90 degree rotation matrix, i.e. a quarter turn. The anti-clockwise rotation... | 3 | Analytical Chemistry |
The IAGC (International Association of GeoChemistry, formerly known as the International Association of Geochemistry and Cosmochemistry) is affiliated with the International Union of Geological Sciences and has been one of the pre-eminent international geochemical organizations for over thirty-five years.
The principa... | 9 | Geochemistry |
Vladimir Vasilyevich Markovnikov, also Markownikoff (; – 11 February 1904) was a Russian chemist, best known for having developed the Markovnikov's rule, that describes addition reactions of hydrogen halides and alkenes. | 0 | Organic Chemistry |
Dye sensitised solar cells operate as a photoanode (n-DSC), where photocurrent result from electron injection by the sensitized dye. Photocathodes (p-DSCs) operate in an inverse mode compared to the conventional n-DSC, where dye-excitation is followed by rapid electron transfer from a p-type semiconductor to the dye (d... | 5 | Photochemistry |
CDP includes three separate legal entities registered in the United Kingdom, Belgium and the United States of America. In the United Kingdom, CDP Worldwide is a charity registered with the Charity Commission for England and Wales. CDP Europe is a registered charity in Brussels, Belgium and Berlin, Germany. CDP North Am... | 2 | Environmental Chemistry |
The ionic mechanism of oxidative addition is similar to the S2 type in that it involves the stepwise addition of two distinct ligand fragments. The key difference being that ionic mechanisms involve substrates which are dissociated in solution prior to any interactions with the metal center. An example of ionic oxidati... | 0 | Organic Chemistry |
The physical properties of solids have been common subjects of scientific inquiry for centuries, but a separate field going by the name of solid-state physics did not emerge until the 1940s, in particular with the establishment of the Division of Solid State Physics (DSSP) within the American Physical Society. The DSSP... | 8 | Metallurgy |
GFAJ-1 is a strain of rod-shaped bacteria in the family Halomonadaceae. It is an extremophile that was isolated from the hypersaline and alkaline Mono Lake in eastern California by geobiologist Felisa Wolfe-Simon, a NASA research fellow in residence at the US Geological Survey. In a 2010 Science journal publication, th... | 1 | Biochemistry |
Craftsmen and designers utilize copper's inherent benefits to build aesthetically pleasing and long-lasting building systems. From cathedrals to castles and from homes to offices, copper is used in many products: low-sloped and pitched roofs, soffits, fascias, flashings, gutters, downspouts, building expansion joints, ... | 8 | Metallurgy |
The majority of systems utilize two two-cylinder piston pumps, one for each buffer, combining the output of both in a mixing chamber. Some simpler systems use a single peristaltic pump which draws both buffers from separate reservoirs through a proportioning valve and mixing chamber. In either case the system allows th... | 3 | Analytical Chemistry |
Endothelium is a thin layer of simple squamous epithelial cells that line the interior of both blood and lymph vessels. The endothelium that lines blood vessels is known as vascular endothelium, which is subject to and must withstand the forces of blood flow and blood pressure from the cardiovascular system. To withsta... | 7 | Physical Chemistry |
The protein encoded by this gene contains a RING zinc finger, a motif known to be involved in protein-protein interactions. This protein interacts with androgen receptor (AR) and may function as a coactivator that induces AR target gene expression in prostate. A dominant negative mutant of this gene has been demonstrat... | 1 | Biochemistry |
The ability of the immune system to recognize molecules that are broadly shared by pathogens is, in part, due to the presence of immune receptors called toll-like receptors (TLRs) that are expressed on the membranes of leukocytes including dendritic cells, macrophages, natural killer cells, cells of the adaptive immuni... | 1 | Biochemistry |
Large amounts of macromolecules in a solution will alter the rates and equilibrium constants of enzyme reactions, through an effect called macromolecular crowding. | 1 | Biochemistry |
The sulfate anions reacting with different phases of the hardened cement paste (HCP) to form more voluminous reaction products can cause 3 types of expansive reactions called sulfate attack inside HCP:
# The delayed ettringite formation (DEF) also known as internal sulfate attack (ISA);
# The external sulfate attack ... | 8 | Metallurgy |
Fenfluramine is an indirect agonist of serotonin receptors. Fenfluramine binds to the serotonin transporter, blocking serotonin reuptake. However, fenfluramine also acts to induce non-exocytotic serotonin release; in a mechanism similar to that of methamphetamine in dopamine neurons, fenfluramine binds to VMAT2, disrup... | 1 | Biochemistry |
Some of the unsolved problems include:
* Off-target effects – The possibility of unwanted, likely harmful, changes to the genome present a large barrier to the widespread implementation of this technology. Improvements to the specificity of gRNAs and Cas enzymes present viable solutions to this issue as well as the ref... | 1 | Biochemistry |
In the Gusev crater of Mars, the Mars Exploration Rover Spirit inadvertently discovered opaline silica. One of its wheels had earlier become immobilized and thus was effectively trenching the Martian regolith as it dragged behind the traversing rover. Later analysis showed that the silica was evidence for hydrotherma... | 1 | Biochemistry |
An intermediate stage in the process of eukaryotic RNA splicing is the formation of a lariat structure. It is anchored at an adenosine residue in intron between 10 and 50 nucleotides upstream of the 3' splice site. A short conserved sequence (the branch point sequence) functions as the recognition signal for the site o... | 1 | Biochemistry |
Elongating polymerase is associated with a set of protein factors required for various types of RNA processing. mRNA is capped as soon as it emerges from the RNA-exit channel of the polymerase. After capping, dephosphorylation of Ser-5 within the CTD repeats may be responsible for dissociation of the capping machinery.... | 1 | Biochemistry |
This reagent is not commercially available due to its short shelf life, so it must be freshly prepared in the laboratory. One common preparation involves two steps. First a few drops of dilute sodium hydroxide are added to some aqueous 0.1 M silver nitrate. The ions convert the silver aquo complex form into silver(I) ... | 3 | Analytical Chemistry |
Thermal mass is effective in improving building comfort in any place that experiences these types of daily temperature fluctuations—both in winter as well as in summer.
When used well and combined with passive solar design, thermal mass can play an important role in major reductions to energy use in active heating and ... | 7 | Physical Chemistry |
Effectively, the postulate states that the structure of a transition state resembles that of the species nearest to it in free energy. This can be explained with reference to potential energy diagrams:
In case (a), which is an exothermic reaction, the energy of the transition state is closer in energy to that of the re... | 7 | Physical Chemistry |
(Diacetoxyiodo)benzene, also known as phenyliodine(III) diacetate (PIDA) is a hypervalent iodine chemical with the formula . It is used as an oxidizing agent in organic chemistry. | 0 | Organic Chemistry |
Metal alkyl complexes are prepared generally by two pathways, use of alkyl nucleophiles and use of alkyl electrophiles. Nucleophilic sources of alkyl ligands include Grignard reagents and organolithium compounds. Since many strong nucleophiles are also potent reductants, mildly nucleophilic alkylating agents are somet... | 0 | Organic Chemistry |
Christopher Alexander Hunter, FRS (born 19 February 1965) is a British chemist and academic. Since 2014, he has been Herchel Smith Professor of Organic Chemistry in the Department of Chemistry at the University of Cambridge. His research is currently focused on molecular recognition. He was previously a lecturer at the... | 0 | Organic Chemistry |
Tammann was awarded the following prizes:
* Liebig Medal of the Association of German Chemists () in 1925
* Heyn Medal of the German Society for Materials Science () in 1929
* Eagle Shield of the German Empire in 1936
The Tammann Commemorative Medal of the Deutsche Gesellschaft für Materialkunde is named after him. | 7 | Physical Chemistry |
Hot (> 300 °C) hydrothermal fluids from mid ocean ridges are isotopically light, with δFe between -0.2 and -0.8‰. Particles in hydrothermal plumes are isotopically heavy relative to the hydrothermal fluids, with δFe between 0.1 and 1.1‰. Hydrothermal deposits have average δFe between -1.6 and 0.3‰. The sulfide minerals... | 9 | Geochemistry |
Despite its beneficial properties, NiAl generally suffers from two factors: very high brittleness at low temperatures (Al-based alloys these issues are generally addressed via the integration of other elements. Attempted elements can be broken into three groups depending on their influence of microstructure:
* Elements... | 8 | Metallurgy |
Many invasive plant species interfere with native plants through allelopathy. A famous case of purported allelopathy is in desert shrubs. One of the most widely known early examples was Salvia leucophylla, because it was on the cover of the journal Science in 1964. Bare zones around the shrubs were hypothesized to be ... | 1 | Biochemistry |
Stearoylethanolamide (SEA) is an endocannabinoid neurotransmitter.
Stearoylethanolamide (CHNO; 18:0), also called N-(octadecanoyl)ethanolamine, is an N-acylethanolamine and the ethanolamide of octadecanoic acid (CHO; 18:0) and ethanolamine (MEA: CHNO), and functionally related to an octadecanoic acid.
Levels of SEA cor... | 1 | Biochemistry |
Another important class of condensation polymers are polyesters. They arise from the reaction of a carboxylic acid and an alcohol. An example is polyethyleneterephthalate, the common plastic PETE (recycling #1 in the USA):
:n HO-X-OH + n HOC-Y-COH → [O-X-OC-Y-C(O)] + (2n-1) HO | 7 | Physical Chemistry |
An example of modest stereoselectivity is the dehydrohalogenation of 2-iodobutane which yields 60% trans-2-butene and 20% cis-2-butene. Since alkene geometric isomers are also classified as diastereomers, this reaction would also be called diastereoselective.
Cram's rule predicts the major diastereomer resulting from t... | 4 | Stereochemistry |
Suppressor of cytokine signaling 1 is a protein that in humans is encoded by the SOCS1 gene. SOCS1 orthologs have been identified in several mammals for which complete genome data are available. | 1 | Biochemistry |
An ISFET electrode sensitive to H concentration can be used as a conventional glass electrode to measure the pH of a solution. However, it also requires a reference electrode to operate. If the reference electrode used in contact with the solution is of the AgCl or HgCl classical type, it will suffer the same limitatio... | 7 | Physical Chemistry |
Different solvents can affect the equilibrium constant of a reaction by differential stabilization of the reactant or product. The equilibrium is shifted in the direction of the substance that is preferentially stabilized.
Stabilization of the reactant or product can occur through any of the different non-covalent int... | 7 | Physical Chemistry |
Since no natural amino acids are strongly nucleophilic, the base in a catalytic triad polarises and deprotonates the nucleophile to increase its reactivity. Additionally, it protonates the first product to aid leaving group departure.
The base is most commonly histidine since its pK allows for effective base catalysis,... | 1 | Biochemistry |
The use of antioxidants to prevent some diseases is controversial. In a high-risk group like smokers, high doses of beta carotene increased the rate of lung cancer since high doses of beta-carotene in conjunction of high oxygen tension due to smoking results in a pro-oxidant effect and an antioxidant effect when oxygen... | 1 | Biochemistry |
When a microscopic machine (e.g. a MEM) performs useful work it generates heat and entropy as a byproduct of the process, however it is also predicted that this machine will operate in "reverse" or "backwards" over appreciable short periods. That is, heat energy from the surroundings will be converted into useful work.... | 7 | Physical Chemistry |
Plasma spraying systems can be categorized by several criteria.
Plasma jet generation:
*direct current (DC plasma), where the energy is transferred to the plasma jet by a direct current, high-power electric arc
*induction plasma or RF plasma, where the energy is transferred by induction from a coil around the plasma je... | 8 | Metallurgy |
LH is released from the pituitary gland along with FSH in response to GnRH release into the hypophyseal portal system. Pulsatile GnRH release causes pulsatile LH and FSH release to occur, which modulates and maintains appropriate levels of bioavailable gonadal hormone: testosterone in males and estradiol in females su... | 1 | Biochemistry |
One of the earliest smelted iron artifacts, a dagger with an iron blade found in a Hattic tomb in Anatolia, dated from 2500 BC. About 1500 BC, increasing numbers of non-meteoritic, smelted iron objects appeared in Mesopotamia, Anatolia and Egypt. Nineteen meteoric iron objects were found in the tomb of Egyptian ruler T... | 8 | Metallurgy |
* Carnot, Sadi (1824). Réflexions sur la puissance motrice du feu et sur les machines propres à développer cette puissance (in French). Paris: Bachelier.
* Dobroborsky B.S. Machine safety and the human factor / Edited by Doctor of Technical Sciences, prof. S.A. Volkov. — St. Petersburg: SPbGASU, 2011. — pp. 33-35. — 11... | 7 | Physical Chemistry |
Proteins are essential macromolecules of living organisms. They are continuously being degraded into their constituent amino acids which can be reused in the synthesis of new proteins. Every cellular protein has its own half-life time. In humans, for instance, 50% of the liver and plasma proteins are replaced in 10 day... | 1 | Biochemistry |
According to Sazonov and Shaw, the dimensionless Bunsen coefficient is defined as "the volume of saturating gas, V1, reduced to T° = 273.15 K, p° = 1 bar, which is absorbed by unit volume V* of pure solvent at the temperature of measurement and partial pressure of 1 bar." If the gas is ideal, the pressure cancels out,... | 7 | Physical Chemistry |
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