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The number average molar mass is a way of determining the molecular mass of a polymer. Polymer molecules, even ones of the same type, come in different sizes (chain lengths, for linear polymers), so the average molecular mass will depend on the method of averaging. The number average molecular mass is the ordinary arit... | 7 | Physical Chemistry |
Common laboratory conductivity meters employ a potentiometric method and four electrodes. Often, the electrodes are cylindrical and arranged concentrically. The electrodes are usually made of platinum metal. An alternating current is applied to the outer pair of the electrodes. The potential between the inner pair is m... | 7 | Physical Chemistry |
Despite its limitations, the OR technique benefited from its close association with the development of the polymerase chain reaction. Kary Mullis, who also worked at Cetus, had synthesized the oligonucleotide probes being tested by Saiki and Erlich. Aware of the problems they were encountering, he envisioned an alterna... | 1 | Biochemistry |
Phytobenthos form biofilm with other microbial populations, including heterotrophic bacteria, which can also produce extracellular polymeric substance to help establish biofilm. Within these diverse communities, phytobenthos sustains the heterotrophs and mixotrophs not only by serving as food themselves. Phytobenthos c... | 5 | Photochemistry |
__NOTOC__
Walter Sidney Metcalf (18 May 1918 – 25 July 2008) was a New Zealand physical chemist.
Metcalf was born in Kaitangata on 18 May 1918, the son of George Metcalf, and was educated at Napier Boys High School. He earned a bachelors degree in music in parallel with his first science degree at the University of Ota... | 7 | Physical Chemistry |
Typically, an ultrashort pulsed laser is used in the terahertz pulse generation process. In the use of low-temperature grown GaAs as an antenna, the ultrashort pulse creates charge carriers that are accelerated to create the terahertz pulse. In the use of non-linear crystals as a source, a high-intensity ultrashort pul... | 7 | Physical Chemistry |
The first total synthesis of carpanone was the biomimetic approach published by Chapman et al. in 1971. The required desmethylcarpacin (2-allylsesamol), shown below as the starting molecule in the scheme, is acquired in two high-yield steps involving three transformations:
* allylation of the phenolic anion generated ... | 0 | Organic Chemistry |
RajanBabu has over 160 publications to date and has co-authored several reviews and patents. His H-index is 56.
Notable publications include:
* Group-transfer polymerization. 1. A new concept for addition polymerization with organosilicon initiators
* Selective Generation of Free Radicals from Epoxides Using a Transiti... | 0 | Organic Chemistry |
An increased thyroxine-binding globulin results in an increased total thyroxine and total triiodothyronine without an actual increase in hormonal activity of thyroid hormones.
Reference ranges: | 1 | Biochemistry |
CRP is used mainly as an inflammation marker. Apart from liver failure, there are few known factors that interfere with CRP production. Interferon alpha inhibits CRP production from liver cells which may explain the relatively low levels of CRP found during viral infections compared to bacterial infections
Measuring a... | 1 | Biochemistry |
The major difference between atomic force microscopy and competing technologies such as optical microscopy and electron microscopy is that AFM does not use lenses or beam irradiation. Therefore, it does not suffer from a limitation in spatial resolution due to diffraction and aberration, and preparing a space for guid... | 6 | Supramolecular Chemistry |
In thermodynamics, a spontaneous process is a process which occurs without any external input to the system. A more technical definition is the time-evolution of a system in which it releases free energy and it moves to a lower, more thermodynamically stable energy state (closer to thermodynamic equilibrium). The sign ... | 7 | Physical Chemistry |
Impermeable plasma is a type of thermal plasma which acts like an impermeable solid with respect to gas or cold plasma and can be physically pushed. Interaction of cold gas and thermal plasma was briefly studied by a group led by Hannes Alfvén in 1960s and 1970s for its possible applications in insulation of fusion pla... | 7 | Physical Chemistry |
The vertical axis is labeled E for the voltage potential with respect to the standard hydrogen electrode (SHE) as calculated by the Nernst equation. The "H" stands for hydrogen, although other standards may be used, and they are for room temperature only.
For a reversible redox reaction described by the following chemi... | 7 | Physical Chemistry |
Hardy worked as assistant professor of organic chemistry at Bryn Mawr College in 1939 and 1940. In the years 1942–1958, Hardy worked as a chemist at Calco Chemical Division, subsequently she worked as a literature chemist at Lederle Labs from 1958 to 1975. After working for Lederle, Hardy worked as a senior resident li... | 0 | Organic Chemistry |
* RRS effect (Resonance Raman Scaterring)
The Raman resonance effect produces an increase in Raman intensity up to 10 times. In this phenomenon, the monochromatic light interaction with the sample produces the transition of the molecules from the fundamental state to an excited electronic state, instead of a virtual st... | 7 | Physical Chemistry |
Micro pitting is a fatigue failure of the surface of a material commonly seen in rolling bearings and gears.
It is also known as grey staining, micro spalling or frosting. | 8 | Metallurgy |
The enantioselective version of the Tsuji–Trost reaction is called the Trost asymmetric allylic alkylation (Trost AAA) or simply, asymmetric allylic alkylation (AAA). These reactions are often used in asymmetric synthesis. The reaction was originally developed with a palladium catalyst supported by the Trost ligand, al... | 0 | Organic Chemistry |
The insertion of alkenes into metal-hydrogen bonds is a key step in hydrogenation and hydroformylation reactions. The reaction involves the alkene and the hydride ligands combining within the coordination sphere of a catalyst. In hydrogenation, the resulting alkyl ligand combines with a second hydride to give the alkan... | 0 | Organic Chemistry |
The lower rim of the cyclooctane B ring containing the first 5 carbon atoms was synthesized in a semisynthesis starting from naturally occurring L-serine (scheme 1). This route started with conversion of the amino group of the serine methyl ester (1) to the diol ester 2 via diazotization (sodium nitrite/sulfuric acid)... | 0 | Organic Chemistry |
The NRTL parameters are fitted to activity coefficients that have been derived from experimentally determined phase equilibrium data (vapor–liquid, liquid–liquid, solid–liquid) as well as from heats of mixing. The source of the experimental data are often factual data banks like the Dortmund Data Bank. Other options ar... | 7 | Physical Chemistry |
Splicing of all intron-containing RNA molecules is superficially similar, as described above. However, different types of introns were identified through the examination of intron structure by DNA sequence analysis, together with genetic and biochemical analysis of RNA splicing reactions. At least four distinct classes... | 1 | Biochemistry |
In materials where the maximum applied-stress-intensity factor exceeds the stress-corrosion cracking-threshold value, stress corrosion adds to crack-growth velocity. This is shown in the schematic on the right. In a corrosive environment, the crack grows due to cyclic loading at a lower stress-intensity range; above th... | 8 | Metallurgy |
eIF2 is an essential factor for protein synthesis that forms a ternary complex (TC) with GTP and the initiator Met-tRNA. After its formation, the TC binds the 40S ribosomal subunit to form the 43S preinitiation complex (43S PIC). 43S PIC assembly is believed to be stimulated by the initiation factors eIF1, eIF1A, and t... | 1 | Biochemistry |
Underpotential deposition (UPD), in electrochemistry, is a phenomenon of electrodeposition of a species (typically reduction of a metal cation to a solid metal) at a potential less negative than the equilibrium (Nernst) potential for the reduction of this metal. The equilibrium potential for the reduction of a metal in... | 7 | Physical Chemistry |
In December 2007, Takeda submitted a New Drug Application (NDA) for alogliptin to the United States Food and Drug Administration (FDA), after positive results from Phase III clinical trials. In September 2008, the company also filed for approval in Japan, winning approval in April 2010. The company also filed a Marke... | 4 | Stereochemistry |
Cannabis (/ˈkænəbɪs/) is commonly known as marijuana or hemp and has two known strains: Cannabis sativa and Cannabis indica, both of which produce chemicals to deter herbivory. The chemical composition includes specialized terpenes and cannabinoids, mainly tetrahydrocannabinol (THC), and cannabidiol (CBD). These substa... | 1 | Biochemistry |
The resulting flow from applying a voltage is a plug flow. Unlike a parabolic profile flow generated from a pressure differential, a plug flow’s velocity profile is approximately planar, with slight variation near the electric double layer. This offers significantly less deleterious dispersive effects and can be contro... | 7 | Physical Chemistry |
In step-growth polymerization, the Carothers equation (or Carothers' equation) gives the degree of polymerization, , for a given fractional monomer conversion, .
There are several versions of this equation, proposed by Wallace Carothers, who invented nylon in 1935. | 7 | Physical Chemistry |
The percent yield is a comparison between the actual yield—which is the weight of the intended product of a chemical reaction in a laboratory setting—and the theoretical yield—the measurement of pure intended isolated product, based on the chemical equation of a flawless chemical reaction, and is defined as,
The ideal... | 0 | Organic Chemistry |
The most frequently introduced forms are:where:
* is the absolute pressure of the gas,
* is the volume of the gas,
* is the amount of substance of gas (also known as number of moles),
* is the ideal, or universal, gas constant, equal to the product of the Boltzmann constant and the Avogadro constant,
* is the Bolt... | 7 | Physical Chemistry |
Fish generally use bioluminescence for camouflage to hide from predators. Endogenous photocytes are more commonly used for bioluminescence than other means like bacteria. Some fish may use the bioluminescence produced by their photocytes as a means of communication. | 1 | Biochemistry |
Hemichromes form an insoluble macromolecule (macromolecular aggregate) by copolymerization with the cytoplasm of band 3. Covalent bonds reinforce the aggregate interactions of the hemichromes which are accumulated on the surface of the membrane. However, hemichromes are less stable than their native form. | 1 | Biochemistry |
Modafinil is occasionally prescribed off-label for individuals with attention deficit hyperactivity disorder (ADHD). It has shown no efficacy in treating adult ADHD, especially when compared to other treatments such as lisdexamfetamine. In children, modafinil is efficient in treating ADHD symptoms.
Given its approved s... | 4 | Stereochemistry |
The eudysmic ratio (also spelled eudismic ratio) represents the difference in pharmacologic activity between the two enantiomers of a drug. In most cases where a chiral compound is biologically active, one enantiomer is more active than the other. The eudysmic ratio is the ratio of activity between the two. A eudysmic ... | 4 | Stereochemistry |
K. C. Nicolaou was born on July 5, 1946, in Karavas, Cyprus where he grew up and went to school until the age of 18. In 1964, he went to England where he spent two years learning English and preparing to enter University. He studied chemistry at the University of London (B.Sc., 1969, Bedford College; Ph.D. 1972, Unive... | 0 | Organic Chemistry |
The Bouguer-Lambert law may be applied to describe the attenuation of solar or stellar radiation as it travels through the atmosphere. In this case, there is scattering of radiation as well as absorption. The optical depth for a slant path is , where refers to a vertical path, is called the relative airmass, and for ... | 7 | Physical Chemistry |
In situ infrared spectroscopy may be used to monitor the course of a reaction, provided a reagent or product shows distinctive absorbance in the IR spectral region. The rate of reactant consumption and/or product formation may be abstracted from the change of absorbance over time (by application of Beers Law). Even whe... | 7 | Physical Chemistry |
During the next thousand years of the Early Bronze Age (end of 4th–end of 3rd millennium BCE) the same unalloyed copper production of the Chalcolithic (group 2, above) continued for the production of short blades and points. The same metal technique was used for the novel production of long blade weapons
(riveted dagge... | 8 | Metallurgy |
The first monosaccharide attached in the synthesis of O-linked glycans is N-acetyl-galactosamine. After this, several different pathways are possible. A Core 1 structure is generated by the addition of galactose. A Core 2 structure is generated by the addition of N-acetyl-glucosamine to the N-acetyl-galactosamine of th... | 0 | Organic Chemistry |
The exponential amplification via reverse transcription polymerase chain reaction provides for a highly sensitive technique in which a very low copy number of RNA molecules can be detected. RT-PCR is widely used in the diagnosis of genetic diseases and, semiquantitatively, in the determination of the abundance of speci... | 1 | Biochemistry |
The EC set maximum residue levels for diphenylamine in 2005. (Annex II and Part B of Annex III to Regulation (EC) No 396/2005). Diphenylamine was one of 84 substances of a European Commission (EC) review program covered by a regulation from 2002 requiring the European Food Safety Authority (EFSA) upon EC request to org... | 3 | Analytical Chemistry |
In 1926, Yakov Frenkel suggested that in an ionic crystal like AgI, in thermodynamic equilibrium, a small fraction of the cations, α, are displaced from their regular lattice sites into interstitial positions. He related α with the Gibbs energy for the formation of one mol of Frenkel pairs, ΔG, as α = exp(-ΔG/2RT), whe... | 7 | Physical Chemistry |
The model proposed by Roberto Germano and his collaborators, who have first observed the effect is based on the known concept of the exclusion zone.
The first observations of a different behaviour of water molecules close to the walls of its container date back to late ‘60s and early ‘70s, when Drost-Hansen, upon revi... | 7 | Physical Chemistry |
* Dr. Vahan Simonyan and Dr. Raja Mazumder presented at the NIH Frontiers in Data Science about HIVE acting as a bridge between research and regulatory analytics. Simonyan also presented on the topic at the 2014 Bio-IT World Expo.
* HIVE was additionally discussed in FedScoop.
* Inside the HIVE, the FDA's Multi-Omics ... | 1 | Biochemistry |
A crop, or croup, is a thin-walled expanded portion of the alimentary tract used for the storage of food prior to digestion. In some birds it is an expanded, muscular pouch near the gullet or throat. In adult doves and pigeons, the crop can produce crop milk to feed newly hatched birds.
Certain insects may have a crop ... | 1 | Biochemistry |
There are two types of thermodynamic instruments, the meter and the reservoir. A thermodynamic meter is any device which measures any parameter of a thermodynamic system. In some cases, the thermodynamic parameter is actually defined in terms of an idealized measuring instrument. For example, the zeroth law states that... | 7 | Physical Chemistry |
In chromatography, resolution is a measure of the separation of two peaks of different retention time t in a chromatogram. | 3 | Analytical Chemistry |
It is common for two monochromators to be connected in series, with their mechanical systems operating in tandem so that they both select the same color. This arrangement is not intended to improve the narrowness of the spectrum, but rather to lower the cutoff level. A double monochromator may have a cutoff about one m... | 7 | Physical Chemistry |
An important functional feature of genes is the phenotype caused by mutations. Mutants can be produced by random mutations or by directed mutagenesis, including site-directed mutagenesis, deleting complete genes, or other techniques. | 1 | Biochemistry |
The Hajos–Parrish–Eder–Sauer–Wiechert reaction, reported in 1971 by several research teams, is an early example of an enantioselective catalytic reaction in organic chemistry. Its scope has been modified and expanded through the development of related reactions including the Michael addition, asymmetric aldol reaction,... | 0 | Organic Chemistry |
Methylotrophy refers to the ability of an organism to use C1-compounds as energy sources. These compounds include methanol, methyl amines, formaldehyde, and formate. Several other less common substrates may also be used for metabolism, all of which lack carbon-carbon bonds. Examples of methylotrophs include the bacter... | 1 | Biochemistry |
Ketenes are generally very reactive, and participate in various cycloadditions. One important process is the dimerization to give propiolactones. A specific example is the dimerization of the ketene of stearic acid to afford alkyl ketene dimers, which are widely used in the paper industry. AKD's react with the hydroxyl... | 0 | Organic Chemistry |
One modern-day method of chiral resolution is used in the organic synthesis of the drug duloxetine:
In one of its steps the racemic alcohol 1 is dissolved in a mixture of toluene and methanol to which solution is added optically active (S)-mandelic acid 3. The alcohol (S)-enantiomer forms an insoluble diastereomeric sa... | 4 | Stereochemistry |
A comet assay can determine the degree of DNA fragmentation in sperm cells. The degree of DNA fragmentation has been associated with outcomes of in vitro fertilization.
The comet has been modified for use with sperm cells as a tool for male infertility diagnosis
To break down these tightly bound protamine proteins in ... | 1 | Biochemistry |
Goniophotometers measure the spatial distribution of light visible to the human eye (often luminous intensity) at specific angular positions, usually covering all spherical angles. | 7 | Physical Chemistry |
Electropositivity is a measure of an element's ability to donate electrons, and therefore form positive ions; thus, it is antipode to electronegativity.
Mainly, this is an attribute of metals, meaning that, in general, the greater the metallic character of an element the greater the electropositivity. Therefore, the al... | 3 | Analytical Chemistry |
The two main approaches to synthesis of N-H, N-alkyl, and N-aryloxaziridines are oxidation of imines with peracids (A) and amination of carbonyls (B).
Additionally, oxidation of chiral imines and oxidation of imines with chiral peracids may yield enantiopure oxaziridines. Some oxaziridines have the unique property of c... | 0 | Organic Chemistry |
Following initial observations that some peptide-peptide complexes could survive MALDI deposition and ionization, studies of large protein complexes using MALDI-MS have been reported. | 1 | Biochemistry |
Within the citric acid cycle in humans, propionyl-CoA, which interacts with oxaloacetate to form methylcitrate, can also catalyzed into methylmalonyl-CoA through carboxylation by propionyl-CoA carboxylase (PCC). Methylmalonyl-CoA is later transformed to succinyl-CoA to be further used in the tricarboxylic acid cycle. P... | 1 | Biochemistry |
Although quite stable, the blue ammonia solutions containing solvated electrons degrade rapidly in the presence of catalysts to give colorless solutions of sodium amide:
:2 [Na(NH)]e → H + 2 NaNH + 10 NH
Electride salts can be isolated by the addition of macrocyclic ligands such as crown ether and cryptands to so... | 0 | Organic Chemistry |
Born and raised in New Orleans, Louisiana, to a professional musician-father and a housewife-mother, Ted Ellis earliest hints of artistic talent began to show at five-years-old. Ellis first attempt at art was a third-grade freehand sketch of a dog from Archie Comics, which he drew so accurately that friends and family ... | 3 | Analytical Chemistry |
Typically the copper oxhide ingots are highly pure (approximately 99 weight percent copper) with trace element content of less than one weight percent. The few tin oxhide ingots that have been available to study are also exceptionally pure. Microscopic analysis of the Uluburun copper oxhide ingots reveals that they are... | 8 | Metallurgy |
The far-eastern blot is for the detection of lipid-linked oligosaccharides. High-performance thin-layer chromatography is first used to separate the lipids by physical and chemical characteristics, then transferred to a blotting matrix before the oligosaccharides are detected by a specific binding protein (i.e. antibo... | 1 | Biochemistry |
It has been shown that the integration of a given synthetic ultrasensitive module with upstream and downstream components often alters its information-processing capabilities. This effects must be taken into account in the design process. | 1 | Biochemistry |
In the case of photochemical reactions, light provides the activation energy. Simplistically, light is one mechanism for providing the activation energy required for many reactions. If laser light is employed, it is possible to selectively excite a molecule so as to produce a desired electronic and vibrational state. E... | 5 | Photochemistry |
An ova bank, or cryobank, or egg cell bank is a facility that collects and stores human ova, mainly from ova donors, primarily for the purpose of achieving pregnancies of either the donor, at a later time (i.e. to overcome issues of infertility), or through third party reproduction, notably by artificial insemination. ... | 1 | Biochemistry |
Because of concerns over Peak oil, pollution and climate change, as well the oil price increases since 2003, non-petroleum alternatives have become more popular. This has led to the introduction of biobitumen alternatives that are more environmentally friendly and nontoxic.
For millions of people living in and around ... | 7 | Physical Chemistry |
When electrodes are placed in an electrolyte and a voltage is applied, the electrolyte will conduct electricity. Lone electrons normally cannot pass through the electrolyte; instead, a chemical reaction occurs at the cathode, providing electrons to the electrolyte. Another reaction occurs at the anode, consuming elec... | 7 | Physical Chemistry |
Leiv Kristen Sydnes (born 9 July 1948) is a Norwegian chemist, specializing in organic chemistry.
He was born in Haugesund, and took his education at the University of Oslo. He has the dr.philos. degree from 1978. He was hired as an associate professor at the University of Tromsø in 1978, and was later promoted to prof... | 0 | Organic Chemistry |
Biocrystallization is the formation of crystals from organic macromolecules by living organisms. This may be a stress response, a normal part of metabolism such as processes that dispose of waste compounds, or a pathology. Template mediated crystallization is qualitatively different from in vitro crystallization. Inhib... | 1 | Biochemistry |
Chiral oxazolidinones have been employed most widely in stereoselective aldol reactions.
Soft enolization with the Lewis acid dibutylboron triflate and the base diisopropylethylamine gives the (Z)-enolate, which undergoes a diastereoselective aldol reaction with an aldehyde substrate. The transformation is particularl... | 4 | Stereochemistry |
Development of the Albion process started during the early nineties led by Mount Isa Mines. It was first patented in 1993. Several pilot plant projects were conducted in 1994 and 1995 which tested the feasibility of using the technology to process high arsenic gold and copper ore.
The Albion Process has been successfu... | 8 | Metallurgy |
Grignard reagents react with a variety of carbonyl derivatives.
The most common application of Grignard reagents is the alkylation of aldehydes and ketones, i.e. the Grignard reaction:
Note that the acetal functional group (a protected carbonyl) does not react.
Such reactions usually involve an aqueous acidic workup, t... | 0 | Organic Chemistry |
The mathematical similarities between the expressions for shear viscocity, thermal conductivity and diffusion coefficient of the ideal (dilute) gas is not a coincidence; It is a direct result of the Onsager reciprocal relations (i.e. the detailed balance of the reversible dynamics of the particles), when applied to the... | 7 | Physical Chemistry |
Aluminothermic reactions are exothermic chemical reactions using aluminium as the reducing agent at high temperature. The process is industrially useful for production of alloys of iron. The most prominent example is the thermite reaction between iron oxides and aluminium to produce iron itself:
: FeO + 2 Al → 2... | 8 | Metallurgy |
Liquid chromatography-mass spectrometry (LC/MS) couples high resolution chromatographic separation with MS detection. As the system adopts the high separation of HPLC, analytes which are in the liquid mobile phase are often ionized by various soft ionization methods including atmospheric pressure chemical ionization (... | 3 | Analytical Chemistry |
Heterodimeric diatomic complexes involving a noble gas and a halide, such as xenon chloride, are common in the construction of excimer lasers, which are excimers' most common application. These lasers take advantage of the fact that excimer components have attractive interactions in the excited state and repulsive inte... | 5 | Photochemistry |
In the mathematical description it is assumed that no clustering occurs within the alloy. Then, for a binary alloy of the form , e.g. , the standard deviation of the composition is given by:
where is the number of atoms within the excitons' volume, i.e. with being the atoms per volume.
In general, the band gap ene... | 7 | Physical Chemistry |
The spectroscopic notation of molecules uses Greek letters to represent the modulus of the orbital angular momentum along the internuclear axis.
The quantum number that represents this angular momentum is Λ.
: Λ = 0, 1, 2, 3, ...
: Symbols: Σ, Π, Δ, Φ
For Σ states, one denotes if there is a reflection in a plane contai... | 7 | Physical Chemistry |
Steroid 11β-hydroxylase, also known as steroid 11β-monooxygenase, is a steroid hydroxylase found in the zona glomerulosa and zona fasciculata of the adrenal cortex. Named officially the cytochrome P450 11B1, mitochondrial, it is a protein that in humans is encoded by the CYP11B1 gene. The enzyme is involved in the bios... | 1 | Biochemistry |
Bromocresol purple (BCP) or 5′,5″-dibromo-o-cresolsulfophthalein, is a dye of the triphenylmethane family (triarylmethane dyes) and a pH indicator. It is colored yellow below pH 5.2, and violet above pH 6.8. In its cyclic sulfonate ester form, it has a pK value of 6.3, and is usually prepared as a 0.04% aqueous solutio... | 3 | Analytical Chemistry |
Lithium is primarily used as a maintenance drug in the treatment of bipolar disorder to stabilize mood and prevent manic episodes, but it may also be helpful in the acute treatment of manic episodes. Although recommended by treatment guidelines for the treatment of depression in bipolar disorder, the evidence that lith... | 1 | Biochemistry |
The clathrate gun hypothesis is a proposed explanation for the periods of rapid warming during the Quaternary. The hypothesis is that changes in fluxes in upper intermediate waters in the ocean caused temperature fluctuations that alternately accumulated and occasionally released methane clathrate on upper continental ... | 6 | Supramolecular Chemistry |
In organic chemistry, a methylidyne group or just methylidyne is a neutral part of a molecule (a substituent or functional group) with formula , consisting of a carbon atom bonded to a hydrogen atom by one single bond and to the rest of the molecule by one triple bond. For example, a methylidyne group is present in n-... | 0 | Organic Chemistry |
In a conventional oil refinery, isobutane is alkylated with low-molecular-weight alkenes (primarily a mixture of propene and butene) in the presence of a Brønsted acid catalyst, which can include solid acids (zeolites). The catalyst protonates the alkenes (propene, butene) to produce carbocations, which alkylate isobut... | 0 | Organic Chemistry |
Stereochemistry has important applications in the field of medicine, particularly pharmaceuticals. An often cited example of the importance of stereochemistry relates to the thalidomide disaster. Thalidomide is a pharmaceutical drug, first prepared in 1957 in Germany, prescribed for treating morning sickness in pregna... | 4 | Stereochemistry |
Transcription is when RNA is copied from DNA. During transcription, RNA polymerase makes a copy of a gene from the DNA to mRNA as needed. This process differs slightly in eukaryotes and prokaryotes. One notable difference is that prokaryotic RNA polymerase associates with DNA-processing enzymes during transcription so ... | 1 | Biochemistry |
An SNP array is a useful tool for studying slight variations between whole genomes. The most important clinical applications of SNP arrays are for determining disease susceptibility and for measuring the efficacy of drug therapies designed specifically for individuals. In research, SNP arrays are most frequently used f... | 1 | Biochemistry |
Structurally, the lac repressor protein is a homotetramer. More precisely, the tetramer contains two DNA-binding subunits composed of two monomers each (a dimer of dimers). Each monomer consists of four distinct regions:
*An N-terminal DNA-binding domain (in which two LacI proteins bind a single operator site)
*A regul... | 1 | Biochemistry |
DNA can also be introduced into cells using viruses as a carrier. In such cases, the technique is called transduction, and the cells are said to be transduced. Adenoviral vectors can be useful for viral transfection methods because they can transfer genes into a wide variety of human cells and have high transfer rates.... | 1 | Biochemistry |
Akin to complexation, phosphines are readily alkylated. For example, methyl bromide converts triphenylphosphine to the methyltriphenylphosphonium bromide, a "quat salt":
:PPh + CHBr → [CHPPh]Br
Phosphines are nucleophilic catalysts in organic synthesis, e.g. the Rauhut–Currier reaction and Baylis-Hillman reaction. | 0 | Organic Chemistry |
Strong hydrogen bonds are revealed by downfield shifts in the H NMR spectrum. For example, the acidic proton in the enol tautomer of acetylacetone appears at 15.5, which is about 10 ppm downfield of a conventional alcohol.
In the IR spectrum, hydrogen bonding shifts the stretching frequency to lower energy (i.e. the ... | 6 | Supramolecular Chemistry |
Ferrier was born in Edinburgh on 7 August 1932. Following the family's idiosyncratic naming tradition, although he was named Robert John, he was always known as Robin. Likewise his father Edward was known as William and his mother Sophia was known as Rita. William was a policeman and became head of Edinburgh CID, while... | 0 | Organic Chemistry |
Cation–pi interactions involve the positive charge of a cation interacting with the electrons in a π-system of a molecule. This interaction is surprisingly strong (as strong or stronger than H-bonding in some contexts), and has many potential applications in chemical sensors. For example, the sodium ion can easily sit ... | 6 | Supramolecular Chemistry |
Retroviruses have been the focus of several recent claims and assertions which have been largely discredited by the science community. An initial study in 2009 seemed to make new findings which might change some of the established knowledge on this topic. However, although later research disproved some of the claims ma... | 1 | Biochemistry |
During the more than 80 years of technical development of sensor-based ore sorting equipment, various types of machines have been developed. This includes the channel-type, bucket-wheel type and cone type sorters. The main machine types being installed in the mining industry today are belt-type and chute-type machines.... | 3 | Analytical Chemistry |
The enzymatic process that produces heme is properly called porphyrin synthesis, as all the intermediates are tetrapyrroles that are chemically classified as porphyrins. The process is highly conserved across biology. In humans, this pathway serves almost exclusively to form heme. In bacteria, it also produces more com... | 1 | Biochemistry |
The electronic conductivity of purified distilled water in electrochemical laboratory settings at room temperature is often between 0.05 and 1 μS/cm. Environmental influences during the peparation of salt solutions as gas absorption due to storing the water in an unsealed beaker may immediately increase the conductivit... | 7 | Physical Chemistry |
* New Discussions on Nanocatalysts in Organic Chemistry, Ilam: Ilam University Press 2018, ISBN 9786006184395
* Drug Delivery Systems and Their Effectiveness Through Nanotechnology, Ilam: Havar 2019, ISBN 9786008473855 | 0 | Organic Chemistry |
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