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Title 15, Chapter 8, Section 291 of the United States Code makes it unlawful to stamp goods in the United States with "United States assay" or any similar stamp which gives the impression that the item has been officially assayed by the United States government.
3
Analytical Chemistry
Acetylides are sometimes intermediates in coupling reactions. Examples include Sonogashira coupling, Cadiot-Chodkiewicz coupling, Glaser coupling and Eglinton coupling.
0
Organic Chemistry
For pol II-transcribed genes, and unlike bacterial RNA polymerase, promoter melting requires hydrolysis of ATP and is mediated by TFIIH. TFIIH is a ten-subunit protein, including both ATPase and protein kinase activities. While the upstream promoter DNA is held in a fixed position by TFIID, TFIIH pulls downstream doub...
1
Biochemistry
Siderophores (Greek: "iron carrier") are small, high-affinity iron-chelating compounds that are secreted by microorganisms such as bacteria and fungi. They help the organism accumulate iron. Although a widening range of siderophore functions is now being appreciated, siderophores are among the strongest (highest affini...
1
Biochemistry
According to a research study conducted Hutton, M et al, a missense mutation occurring on the 5 region of the RNA associated with the tau protein was found to be correlated with inherited dementia (known as FTDP-17). The splice-site mutations all destabilize a potential stem–loop structure which is most likely involved...
1
Biochemistry
Sucrose esters are stable in the pH range of 4 to 8, so they can be used as an additive in most foods. At pH higher than 8, saponification (hydrolysis of the ester bond to release the original sucrose and the salt of fatty acids) might occur. Hydrolysis could also occur at pH lower than 4.
0
Organic Chemistry
The presence of harmful algae blooms can lead to hypoxia or anoxia in a body of water. The depletion of oxygen within a body of water can lead to the creation of a dead zone. Dead zones occur when a body of water has become unsuitable for organism survival in that location. HABs cause dead zones by consuming oxygen in ...
3
Analytical Chemistry
The objective of the refinement process is to find equilibrium constant values that give the best fit to the experimental data. This is usually achieved by minimising an objective function, , by the method of non-linear least-squares. First the residuals are defined as Then the most general objective function is given ...
7
Physical Chemistry
There are other proteins that have acetylating abilities but differ in structure to the previously mentioned families. One HAT is called steroid receptor coactivator 1 (SRC1), which has a HAT domain located at the C-terminus end of the protein along with a basic helix-loop-helix and PAS A and PAS B domains with a LXXLL...
0
Organic Chemistry
In organic chemistry, the Hammett plot provides a means to assess substituent effects on a reaction equilibrium or rate using the Hammett equation (1): Hammett developed this equation from equilibrium constants from the dissociation of benzoic acid and derivatives (Fig. 1): Hammett defined the equation based on two par...
7
Physical Chemistry
Spermatozoon is the male gamete. After ejaculation this cell is not mature, so it can not fertilize the oocyte. To have the ability to fertilize the female gamete, this cell suffers capacitation and acrosome reaction in female reproductive tract. The signaling pathways best described for spermatozoon involve these pro...
7
Physical Chemistry
The stereoelectronic effect influences the thermodynamics of equilibrium. For example, the following equilibrium could be achieved via a cascade of pericyclic reactions. Despite very similar structures, one of the two isomers is strongly favored over the other because of a stereoelectronic effect. Since the σ* orbital ...
4
Stereochemistry
Overdosing experiments in animals showed loss of body control and drooping, difficulty breathing, tremors, and convulsions. Doses in excess of 1500 mg/kg orally and 250 mg/kg IV produced significant mortality in rodents. In the event of an acute overdosage, authorities recommend unspecific standard procedures such as e...
4
Stereochemistry
Most plant pathogens invade the apoplasm by releasing pectolytic enzymes which facilitate the spread of the invading organism. Bacteria frequently infect plants by gaining entry to the tissue via the stomata. Having entered the plant they spread and multiply in the intercellular spaces. With bacterial vascular diseases...
1
Biochemistry
AOAC International is a 501(c) non-profit scientific association with headquarters in Rockville, Maryland. It was founded in 1884 as the Association of Official Agricultural Chemists (AOAC) and became AOAC International in 1991. It publishes standardized, chemical analysis methods designed to increase confidence in the...
3
Analytical Chemistry
Fumaric acid is an organic compound with the formula HOCCH=CHCOH. A white solid, fumaric acid occurs widely in nature. It has a fruit-like taste and has been used as a food additive. Its E number is E297. The salts and esters are known as fumarates. Fumarate can also refer to the ion (in solution). Fumaric acid is t...
1
Biochemistry
The autocorrelations above assume that the fluctuations are not due to changes in the fluorescent properties of the particles. However, for the majority of (bio)organic fluorophores—e.g. green fluorescent protein, rhodamine, Cy3 and Alexa Fluor dyes—some fraction of illuminated particles are excited to a triplet state ...
7
Physical Chemistry
The chiral pool is a "collection of abundant enantiopure building blocks provided by nature" used in synthesis. In other words, a chiral pool would be a large quantity of common organic enantiomers. Contributors to the chiral pool are amino acids, sugars, and terpenes. Their use improves the efficiency of total synthes...
0
Organic Chemistry
Pure calcium carbide is a colourless solid. The common crystalline form at room temperature is a distorted rock-salt structure with the C</sup> units lying parallel. There are three different polymorphs which appear at room temperature: the tetragonal structure and two different monoclinic structures.
8
Metallurgy
The maximum density of a substance is the highest attainable density of the substance under given conditions.
7
Physical Chemistry
The MCSGP process consists of several, at least two, chromatographic columns which are switched in position opposite to the flow direction. Most of the columns are equipped with a gradient pump to adjust the modifier concentration at the column inlet. Some columns are connected directly, so that non pure product stream...
3
Analytical Chemistry
The effects on animals occur very rapidly and strongly, all resulting in death. Exposure to a high concentration of MFA vapor does not show any symptoms in animals until 30–60 minutes. Then violent reactions and death took place in a few hours, according to studies. From intravenous injection mice, rats, and guinea pig...
1
Biochemistry
The Annual Review of Physical Chemistry published its first volume in 1950. Its founding editor was University of California chemist Gerhard Krohn Rollefson. Some branches of physical chemistry were designated to be reviewed with each volume, while other branches would be reviewed less frequently. Upon Rollefsons death...
7
Physical Chemistry
Telomere length varies greatly between species, from approximately 300 base pairs in yeast to many kilobases in humans, and usually is composed of arrays of guanine-rich, six- to eight-base-pair-long repeats. Eukaryotic telomeres normally terminate with 3′ single-stranded-DNA overhang ranging from 75 to 300 bases, whic...
1
Biochemistry
Allosteric modulators of small SK channels work by changing the apparent calcium sensitivity of the channels. Examples include: * Riluzole * Non-selective positive modulators of SK channels: EBIO (1-Ethyl-2-BenzimIdazolinOne), NS309 (6,7-dichloro-1H-indole-2,3-dione 3-oxime) * SK-2 and SK-3 selective positive modulato...
1
Biochemistry
Yoon has started his independent career in 2005 in the chemistry department at the University of Wisconsin-Madison where he has been ever since. His group specializes in studying the atomic level of control and molecular shape that can be manipulated by chemical synthesis. He has a research group that studies high ener...
0
Organic Chemistry
Within the field of molecular biology, a protein-fragment complementation assay, or PCA, is a method for the identification and quantification of protein–protein interactions. In the PCA, the proteins of interest ("bait" and "prey") are each covalently linked to fragments of a third protein (e.g. DHFR, which acts as a...
1
Biochemistry
Cytochrome c is a highly conserved protein across the spectrum of eukaryotic species, found in plants, animals, fungi, and many unicellular organisms. This, along with its small size (molecular weight about 12,000 daltons), makes it useful in studies of cladistics. Cytochrome c has been studied for the glimpse it gives...
1
Biochemistry
In biology, scaffold proteins are crucial regulators of many key signalling pathways. Although scaffolds are not strictly defined in function, they are known to interact and/or bind with multiple members of a signalling pathway, tethering them into complexes. In such pathways, they regulate signal transduction and he...
1
Biochemistry
Pyrite (FeS) is a mineral formed by the reaction of hydrogen sulfide (HS) and bioreactive iron (Fe). In oxic bottom waters pyrite can only form in sediments where HS is present. However, in iron-rich euxinic environments, pyrite formation can occur at higher rates in both the water column and in sediments due to higher...
9
Geochemistry
The presence of fulgurites in an area can be used to estimate the frequency of lightning over a period of time, which can help to understand past regional climates. Paleolightning is the study of various indicators of past lightning strikes, primarily in the form of fulgurites and lightning-induced remanent magnetizati...
9
Geochemistry
MFGM bioactive protein components, including the glycoproteins lactadherin, MUC-1, and butyrophilin, have been shown in preclinical studies to affect immune response. These components influence the immune system by several mechanisms, including interference with microbe adhesion to intestinal epithelia, bacteriocidal a...
1
Biochemistry
In the same year that Brønsted and Lowry published their theory, G. N. Lewis created an alternative theory of acid–base reactions. The Lewis theory is based on electronic structure. A Lewis base is a compound that can give an electron pair to a Lewis acid, a compound that can accept an electron pair. Lewis's proposal e...
7
Physical Chemistry
In the 1990s, the Niihama copper refinery, owned by Sumitomo Metal Mining Company Limited (“Sumitomo”), treated copper anode slimes generated in-house, together with anode slimes from Sumitomo’s Toyo refinery and lead refinery slime from the Harima Imperial Smelting Process smelter. A total of 1200 tonnes per year (“t/...
8
Metallurgy
Cecil Czerkinsky first described ELISpot in 1983 as a new way to quantify the production of an antigen-specific immunoglobulin by hybridoma cells. In 1988, Czerkinsky developed an ELISA spot assay that quantified the secretion of a lymphokine by T cells. In the same year, dual-color ELISpot was combined with computer i...
1
Biochemistry
MAO is well known as catalyst activator for olefin polymerizations by homogeneous catalysis. In traditional Ziegler–Natta catalysis, supported titanium trichloride is activated by treatment with trimethylaluminium (TMA). TMA only weakly activates homogeneous precatalysts, such as zirconacene dichloride. In the mid-19...
7
Physical Chemistry
In analytical chemistry, glow discharges are usually operated in direct-current mode. For direct-current, the cathode (which is the sample in solids analysis) must be conductive. In contrast, analysis of a non conductive cathode requires the use of a high frequency alternating current. The potential, pressure, and cur...
3
Analytical Chemistry
When producers, importers or authorities test a sample for the unintended presence of GMOs, they usually do not know which GMO to expect. While EU authorities prefer an event-specific approach to this problem, US authorities rely on construct-specific test schemes.
1
Biochemistry
Methane has a very light δC signature: biogenic methane of −60‰, thermogenic methane −40‰. The release of large amounts of methane clathrate can impact on global δC values, as at the Paleocene–Eocene Thermal Maximum. More commonly, the ratio is affected by variations in primary productivity and organic burial. Organis...
9
Geochemistry
In chemistry, hexol is a cation with formula {[Co(NH)(OH)]Co} — a coordination complex consisting of four cobalt cations in oxidation state +3, twelve ammonia molecules , and six hydroxy anions , with a net charge of +6. The hydroxy groups act as bridges between the central cobalt atom and the other three, which carry...
4
Stereochemistry
The nano guitar is a microscopically small carved guitar. It was developed by Dustin W. Carr in 1997, under the direction of Professor Harold G. Craighead, in the Cornell Nanofabrication Facility. The idea came about as a fun way to illustrate nanotechnology, and captured popular attention. It is disputed as to whether...
6
Supramolecular Chemistry
There is evidence for high concentrations of over 6,000 ppm between 600 and 400 million years ago, and of over 3,000 ppm between 200 and 150 million years ago. Indeed, higher CO concentrations are thought to have prevailed throughout most of the Phanerozoic Eon, with concentrations four to six times current concentrat...
2
Environmental Chemistry
Boyle, Charles and Gay-Lussac laws, together with Avogadro's law, were combined by Émile Clapeyron in 1834, giving rise to the ideal gas law. At the end of the 19th century, later developments from scientists like August Krönig, Rudolf Clausius, James Clerk Maxwell and Ludwig Boltzmann, gave rise to the kinetic theory ...
7
Physical Chemistry
Amoxicillin is used to treat odontogenic infections, infections of the tongue, lips, and other oral tissues. It may be prescribed following a tooth extraction, particularly in those with compromised immune systems.
4
Stereochemistry
Plant disease resistance is crucial to the reliable production of food, and it provides significant reductions in agricultural use of land, water, fuel and other inputs. Plants in both natural and cultivated populations carry inherent disease resistance, but this has not always protected them. The late blight Great Fam...
1
Biochemistry
A chemical system is said to be in equilibrium when the quantities of the chemical entities involved do not and cannot change in time without the application of an external influence. In this sense a system in chemical equilibrium is in a stable state. The system at chemical equilibrium will be at a constant temperatur...
7
Physical Chemistry
VMATs are found in a variety of cell types throughout the body, however, VMAT1 is found exclusively in neuroendocrine cells, in contrast to VMAT2, which is also found in the PNS and CNS. Specifically, VMAT1 is found in chromaffin cells, enterochromaffin cells, and small intensely fluorescent cells (SIFs). Chromaffin...
1
Biochemistry
In the years up to 1960 the following approximate division of Fulmer's income applied: about 25% of project work was for UK Government defence agencies; 25% for the Atomic Energy Authority and another 10% for other Government agencies. About 10% was for US Government agencies (the US Air Force and the Office of Aerospa...
8
Metallurgy
In most open ocean ecosystems only a small fraction of organic matter reaches the seafloor. Biological activity in the photic zone of most water bodies tends to recycle material so well that only a small fraction of organic matter ever sinks out of that top photosynthetic layer. Remineralisation within this top layer o...
9
Geochemistry
The PFA-100 (Platelet Function Assay or Platelet Function Analyser) is a platelet function analyser that aspirates blood in vitro from a blood specimen into disposable test cartridges through a microscopic aperture cut into a biologically active membrane at the end of a capillary. The membrane of the cartridges are coa...
1
Biochemistry
CD96 (Cluster of Differentiation 96) or Tactile (T cell activation, increased late expression) is a protein that in humans is encoded by the CD96 gene. CD96 is a receptor protein which is expressed on T cells and NK cells and shares sequence similarity with CD226 (also known as DNAM-1). The protein encoded by this gen...
1
Biochemistry
A thiophosphonate group is a functional group related to phosphonate by substitution of an oxygen atom for a sulphur. They are a reactive component of many pesticides and nerve agents. Substituted thiophosphonates can have 2 main structural isomers bonding though either O or S groups to give thione and thiol forms resp...
0
Organic Chemistry
Inhalation of sulfuryl fluoride is hazardous and may result in respiratory irritation, pulmonary edema, nausea, abdominal pain, central nervous system depression, numbness in the extremities, muscle twitching, seizures, and death. These high exposures occurred when people entered into structures illegally during fumiga...
2
Environmental Chemistry
Biological signaling networks incorporate a wide array of reversible interactions, post-translational modifications and conformational changes. Furthermore, it is common for a protein to be composed of several - identical or nonidentical - subunits, and for several proteins and/or nucleic acid species to assemble into ...
1
Biochemistry
As the environment is altered through physical means (dredging), the occurring reactions change resulting in a decrease of the availability of nutrients and chemical species to plant species and the ecosystem. This then further changes the physical environment as these species are no longer able to survive. The loss of...
9
Geochemistry
Addition-elimination reactions are addition reactions immediately followed by elimination reactions. In general, these reactions take place when esters (or related functional groups) react with nucleophiles. In fact, the only requirement for an addition-elimination reaction to proceed is that the group being eliminat...
0
Organic Chemistry
YwIE is a member of the low-molecular-weight protein tyrosine phosphatase (LMW-PTP). It is the only active PAP present in B.subtilis, and PAPs exhibits almost no activity against Protein Serine, Protein Tyrosine, and Protein Threonine peptides. Also, YwIE has been shown to play a role in B.Subtilis's resistance to stre...
1
Biochemistry
Although the sequestration of marine carbon is a primary outcome of the biological pump, the recycling of nutrients such as N and P in organic matter plays a comparatively important role in maintaining the processes that facilitate this carbon export without removing nutrients for primary production. One key difference...
9
Geochemistry
The increased complexity of the phosphorelay system compared to orthodox two-component signaling provides additional opportunities for regulation and improves the specificity of the response. Although there is very little cross-talk between orthodox two-component systems, phosphorelays allow more complex signaling path...
1
Biochemistry
Flammability is the ease with which a combustible substance can be ignited, causing fire or combustion or even an explosion. The degree of difficulty required to cause the combustion of a substance is quantified through fire testing. Internationally, a variety of test protocols exist to quantify flammability. The ratin...
7
Physical Chemistry
Moroidin is a biologically active compound found in the plants Dendrocnide moroides and Celosia argentea. It is a peptide composed of eight amino acids, with unusual leucine-tryptophan and tryptophan-histidine cross-links that form its two rings. Moroidin has been shown to be at least one of several bioactive compounds...
0
Organic Chemistry
The Krupp–Renn process was a direct reduction steelmaking process used from the 1930s to the 1970s. It used a rotary furnace and was one of the few technically and commercially successful direct reduction processes in the world, acting as an alternative to blast furnaces due to their coke consumption. The Krupp-Renn pr...
8
Metallurgy
Lee (1977) designed a seepage meter, which consists of a chamber which is connected to a sampling port and a plastic bag. The chamber is inserted into the sediment and water discharging through the sediments is caught within the plastic bag. The change in volume of water which is caught in the plastic bag over time rep...
9
Geochemistry
The journal is abstracted and indexed in: * Academic Search * Aquatic Sciences & Fisheries Abstracts * Chemical Abstracts Service * Current Contents/Physical, Chemical & Earth Sciences * GeoRef * Science Citation Index According to the Journal Citation Reports, the journal has a 2018 impact factor of 4.256, ranking it ...
9
Geochemistry
Aerosol is defined as a suspension system of solid or liquid particles in a gas. An aerosol includes both the particles and the suspending gas, which is usually air. Meteorologists usually refer them as particle matter - PM2.5 or PM10, depending on their size. Frederick G. Donnan presumably first used the term aerosol ...
7
Physical Chemistry
With the advent of the high-throughput DNA and RNA sequence identification methods (such as Illumina sequencing), it became possible to efficiently analyse nucleotide sequences of large numbers of relatively short DNA and RNA fragments. Sequences of these fragments can be superimposed to reconstruct the source. Alterna...
1
Biochemistry
When used as a fully supported roof covering, copper is half the weight (including substrate) of lead and only a quarter of tiled roofs. This generally provides savings in supporting structure and materials costs. Copper cladding offers additional opportunities to reduce the weight of copper structures (For more detail...
8
Metallurgy
In haloalkanes and haloarenes (), Halogen functional groups are prefixed with the bonding position and take the form of fluoro-, chloro-, bromo-, iodo-, etc., depending on the halogen. Multiple groups are dichloro-, trichloro-, etc., and dissimilar groups are ordered alphabetically as before. For example, (chloroform)...
0
Organic Chemistry
As a form of energy, heat has the unit joule (J) in the International System of Units (SI). In addition, many applied branches of engineering use other, traditional units, such as the British thermal unit (BTU) and the calorie. The standard unit for the rate of heating is the watt (W), defined as one joule per second. ...
7
Physical Chemistry
Media for 3D optical data storage have been suggested in several form factors: disk, card and crystal. A disc media offers a progression from CD/DVD, and allows reading and writing to be carried out by the familiar spinning disc method. A credit card form factor media is attractive from the point of view of portability...
5
Photochemistry
Wohl model may refer to: * Wohl equation of state: an empirical model for a real gas proposed by A. Wohl * an empirical model for the excess Gibbs free energy of mixing which has been formulated for ternary solutions by K. Wohl (1946, 1953)
7
Physical Chemistry
The resistivity of solvent extract (ROSE) test is a test for the presence and average concentration of soluble ionic contaminants, for example on a printed circuit board (PCB). It was developed in the early 1970s. Some manufacturers use it as part of Six Sigma processes. Some modern fluxes have low solubility in tradit...
3
Analytical Chemistry
The technique has been used to evolve aptamers of extremely high binding affinity to a variety of target ligands, including small molecules such as ATP and adenosine and proteins such as prions and vascular endothelial growth factor (VEGF). Moreover, SELEX has been used to select high-affinity aptamers for complex targ...
1
Biochemistry
In chemistry, the standard state of a material (pure substance, mixture or solution) is a reference point used to calculate its properties under different conditions. A degree sign (°) or a superscript Plimsoll symbol () is used to designate a thermodynamic quantity in the standard state, such as change in enthalpy (ΔH...
7
Physical Chemistry
Benzene is an organic chemical compound with the molecular formula CH. The benzene molecule is composed of six carbon atoms joined in a planar hexagonal ring with one hydrogen atom attached to each. Because it contains only carbon and hydrogen atoms, benzene is classed as a hydrocarbon. Benzene is a natural constituent...
2
Environmental Chemistry
A protecting group or protective group is introduced into a molecule by chemical modification of a functional group to obtain chemoselectivity in a subsequent chemical reaction, facilitating multistep organic synthesis. *Boc for the t-butoxycarbonyl group *Cbz or Z for the carboxybenzyl group *Fmoc for the fluorenylmet...
0
Organic Chemistry
Type I restriction enzymes were the first to be identified and were first identified in two different strains (K-12 and B) of E. coli. These enzymes cut at a site that differs, and is a random distance (at least 1000 bp) away, from their recognition site. Cleavage at these random sites follows a process of DNA transloc...
1
Biochemistry
Chiral switch, a re-engineering approach, has enabled in the remarketing of a number of racemic drugs as chiral specific enantiomer products. Chiral switching strategy is the way most blockbuster drugs have entered the market as enantiopure drugs. A more appropriate term may be unichiral. But the alternate route is de...
4
Stereochemistry
The entrance to the active site for this enzyme is made up mainly of several arginine, histidine, serine, and aspartate side-chains, with a glutamate side-chain playing a secondary role. These side-chains, to be specific Arg359, Arg528, His469, and Ser386, are conserved within each transketolase enzyme and interact wit...
5
Photochemistry
Phosphonium iodide is prepared by mixing diphosphorus tetraiodide () with elemental phosphorus and water at 80 °C and allowing the salt to sublime.
0
Organic Chemistry
Mature messenger RNA, often abbreviated as mature mRNA is a eukaryotic RNA transcript that has been spliced and processed and is ready for translation in the course of protein synthesis. Unlike the eukaryotic RNA immediately after transcription known as precursor messenger RNA, mature mRNA consists exclusively of exo...
1
Biochemistry
Source: If a solid body is modeled by a constant field and the structure of the field is such that it has a penetrable core, then Here is the position of the dividing surface, is the external force field, simulating a solid, is the field value deep in the solid, , is the Boltzmann constant, and is the temperature....
7
Physical Chemistry
RiAFP refers to an antifreeze protein (AFP) produced by the Rhagium inquisitor longhorned beetle. It is a type V antifreeze protein with a molecular weight of 12.8 kDa; this type of AFP is noted for its hyperactivity. R. inquisitor is a freeze-avoidant species, meaning that, due to its AFP, R. inquisitor prevents its b...
1
Biochemistry
Dialysis is generally performed in clipped bags of dialysis tubing or in a variety of formatted dialyzers. The choice of the dialysis set up used is largely dependent on the size of the sample and the preference of the user. Dialysis tubing is the oldest and generally the least expensive format used for dialysis in the...
1
Biochemistry
Orcein, also archil, orchil, lacmus and C.I. Natural Red 28, are names for dyes extracted from several species of lichen, commonly known as "orchella weeds", found in various parts of the world. A major source is the archil lichen, Roccella tinctoria. Orcinol is extracted from such lichens. It is then converted to orce...
3
Analytical Chemistry
β-Lysine (3,6-diaminohexanoic acid) is an amino acid produced by platelets during coagulation and is directly antibacterial by causing lysis of many Gram positive bacteria by acting as a cationic detergent.
1
Biochemistry
Phosphorylated amino acids are crucial for the modulation of the binding of transcription factors and other gene regulatory proteins. Pin1s effect on isomerization of proline residues leads to an increase or decrease in recruitment of phosphatases, namely Scp1 and Ssu72 and their recruitment to the RNAP II CTD. The cis...
4
Stereochemistry
A Markov process is called a reversible Markov process or reversible Markov chain if it satisfies the detailed balance equations. These equations require that the transition probability matrix P for the Markov process possess a stationary distribution (i.e. equilibrium probability distribution) π such that where P is t...
7
Physical Chemistry
Ibuprofen is practically insoluble in water, but very soluble in most organic solvents like ethanol (66.18g/100mL at 40°C for 90% EtOH), methanol, acetone and dichloromethane. The original synthesis of ibuprofen by the Boots Group started with the compound isobutylbenzene. The synthesis took six steps. A modern, greene...
4
Stereochemistry
By definition, antagonists display no efficacy to activate the receptors they bind. Antagonists do not maintain the ability to activate a receptor. Once bound, however, antagonists inhibit the function of agonists, inverse agonists, and partial agonists. In functional antagonist assays, a dose-response curve measures t...
1
Biochemistry
Terphthalaldehyde is used in the preparation of imines, which are also commonly referred to as Schiff bases, following a condensation reaction with amines. During this reaction, water is also formed. This reaction is also reversible. However, due to aromatic conjugation with the benzene ring, the imines are relatively ...
0
Organic Chemistry
In 1989 and 1993, Yamada and co-workers reported the first enantioselective total synthesis of both the enantiomers of ptaquilosin, the aglycone of ptaquiloside. In the first step, the menthyl ester of cyclopentane-1,2-dicarboxylic acid 1 was partially hydrolyzed to afford the monomenthyl ester, which was later alkylat...
0
Organic Chemistry
Radial chromatography is a form of chromatography, a preparatory technique for separating chemical mixtures. It can also be referred to as centrifugal thin-layer chromatography. It is a common technique for isolating compounds and can be compared to column chromatography as a similar process. A common device used for t...
3
Analytical Chemistry
An alloy of NiAl, known as IC-221M, is made up of nickel aluminide combined with several other metals including chromium, molybdenum, zirconium and boron. Adding boron increases the ductility of the alloy by positively altering the grain boundary chemistry and promoting grain refinement. The Hall-Petch parameters for ...
8
Metallurgy
Enzymes responsible for AMPylation, called AMPylators or Adenylyltransferase, fall into two different families, all depending on their structural properties and mechanism used. AMPylator is created by two catalytic homologous halves. One half is responsible for catalyzing the adenylylation reaction, while the other hal...
1
Biochemistry
The milk fat globule is surrounded by a phospholipid trilayer containing associated proteins, carbohydrates, and lipids derived primarily from the membrane of the secreting mammary epithelial cell (lactocyte). This trilayer is collectively known as MFGM. While MFGM makes up only an estimated 2% to 6% of the total milk ...
1
Biochemistry
The first device which used a scintillator was built in 1903 by Sir William Crookes and used a ZnS screen. The scintillations produced by the screen were visible to the naked eye if viewed by a microscope in a darkened room; the device was known as a spinthariscope. The technique led to a number of important discoverie...
5
Photochemistry
Structures of eIF4F components have been solved individually and as partial complexes by a variety of methods, but no complete structure of eIF4F is currently available.
1
Biochemistry
Plane-wave topography is in some sense the opposite of white-beam topography, making use of monochromatic (single-wavelength) and parallel incident beam. In order to achieve diffraction conditions, the sample under study must be precisely aligned. The contrast observed strongly depends on the exact position of the angu...
3
Analytical Chemistry
N-Linked glycosylation involves oligosaccharide attachment to asparagine via a beta linkage to the amine nitrogen of the side chain. The process of N-linked glycosylation occurs cotranslationally, or concurrently while the proteins are being translated. Since it is added cotranslationally, it is believed that N-linked ...
0
Organic Chemistry