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A sophorolipid is a surface-active glycolipid compound that can be synthesized by a selected number of non-pathogenic yeast species. They are potential bio-surfactants due to their biodegradability and low eco-toxicity. | 0 | Organic Chemistry |
At least five different kinds of snRNPs join the spliceosome to participate in splicing. They can be visualized by gel electrophoresis and are known individually as: U1, U2, U4, U5, and U6. Their snRNA components are known, respectively, as: U1 snRNA, U2 snRNA, U4 snRNA, U5 snRNA, and U6 snRNA.
In the mid-1990s, it was... | 1 | Biochemistry |
In biogeochemistry, remineralisation (or remineralization) refers to the breakdown or transformation of organic matter (those molecules derived from a biological source) into its simplest inorganic forms. These transformations form a crucial link within ecosystems as they are responsible for liberating the energy store... | 9 | Geochemistry |
These occur between alkenes and electrophiles, often halogens as in halogen addition reactions. Common reactions include use of bromine water to titrate against a sample to deduce the number of double bonds present. For example, ethene + bromine → 1,2-dibromoethane:
:CH + Br → BrCHCHBr
This takes the form of 3 main ste... | 7 | Physical Chemistry |
Ibuprofen, polyunsaturated fatty acids, and beta-blockers have been reported in some preliminary studies to decrease REE, which may allow patients to meet their caloric needs and gain weight. | 1 | Biochemistry |
A mutation in genes encoding 11β-hydroxylase is associated with congenital adrenal hyperplasia due to 11β-hydroxylase deficiency.
11β-hydroxylase is involved in the metabolism of 17α-hydroxyprogesterone to 21-deoxycortisol, in cases of congenital adrenal hyperplasia due to 21-hydroxylase deficiency. | 1 | Biochemistry |
The global cooling potential of various areas around the world varies primarily based on climate zones and the presence of weather patterns and events. Dry and hot regions generally have a higher radiative cooling power (estimated up to 120 W/m2), while colder regions or those with high humidity or cloud cover generall... | 7 | Physical Chemistry |
In condensed matter physics, second sound is a quantum mechanical phenomenon in which heat transfer occurs by wave-like motion, rather than by the more usual mechanism of diffusion. Its presence leads to a very high thermal conductivity. It is known as "second sound" because the wave motion of entropy and temperature i... | 7 | Physical Chemistry |
Functions can be binding motifs that bind another macromolecule or small compound, that induce a covalent modification of minimotif, or are involved in the protein trafficking of the protein containing the minimotif. The basic premise of Minimotif Miner is that is a short peptide sequence is known to have a function in... | 1 | Biochemistry |
With nuclear magnetic resonance (NMR) spectra the observed chemical shift value, , arising from a given atom contained in a reagent molecule and one or more complexes of that reagent, will be the concentration-weighted average of all shifts of those chemical species. Chemical exchange is assumed to be rapid on the NMR ... | 6 | Supramolecular Chemistry |
To encode arbitrary data in DNA, the data is typically first converted into ternary (base 3) data rather than binary (base 2) data. Each digit (or "trit") is then converted to a nucleotide using a lookup table. To prevent homopolymers (repeating nucleotides), which can cause problems with accurate sequencing, the resul... | 1 | Biochemistry |
Atomic-force microscopy (AFM) is a powerful microscopy technique used for studying samples at a nanoscale and is often used to image protein distribution on a surface. It consists of a cantilever with a tip to scan over the surface. It is a valuable tool for measuring protein-protein and protein-surface interaction. Ho... | 1 | Biochemistry |
Primary (1°) phosphines, with the formula RPH, are typically prepared by alkylation of phosphine. Simple alkyl derivatives such as methylphosphine (CHPH) are prepared by alkylation of alkali metal derivatives MPH (M is Li, Na, or K). Another synthetic route involves treatment of the corresponding chlorophosphines wit... | 0 | Organic Chemistry |
*Karl Fischer titration: A potentiometric method to analyze trace amounts of water in a substance. A sample is dissolved in methanol, and titrated with Karl Fischer reagent (consists of iodine, sulfur dioxide, a base and a solvent, such as alcohol). The reagent contains iodine, which reacts proportionally with water. T... | 3 | Analytical Chemistry |
All bacterial species that have been reported to possess bioluminescence belong within the families Vibrionaceae, Shewanellaceae, or Enterobacteriaceae, all of which are assigned to the class Gammaproteobacteria.
(List from Dunlap and Henryk (2013), "Luminous Bacteria", The Prokaryotes ) | 1 | Biochemistry |
Much of the chemistry of glycosides is explained in the article on glycosidic bonds. For example, the glycone and aglycone portions can be chemically separated by hydrolysis in the presence of acid and can be hydrolyzed by alkali. There are also numerous enzymes that can form and break glycosidic bonds. The most import... | 0 | Organic Chemistry |
Acarbose is a pseudotetrasaccharide mimicking maltotetraose (a substructure of starch). One of the glucose units has been replaced by valienamine - a carbasugar, linked to the next carbohydrate by an amine bridge. Another of the glucose units appears as a 6-deoxy variant. Acarbose is an enzyme inhibitor that is used as... | 1 | Biochemistry |
Under thermal effect, the end of polymer chain departs, and forms low free radical which has low activity. Then according to the chain reaction mechanism, the polymer loses the monomer one by one. However, the molecular chain doesn't change a lot in a short time. The reaction is shown below. This process is common for ... | 7 | Physical Chemistry |
Any reaction in the domain of photogeochemistry, either observed in the environment or studied in the laboratory, may be broadly classified according to the nature of the materials involved.
# Reactions among naturally occurring compounds. Photogeochemistry, both observational and exploratory, is concerned with reactio... | 5 | Photochemistry |
CAF commonly occurs between adjacent vias (i.e. plated through holes) inside a PCB, as the copper migrates along the glass/resin interface from anode to cathode. CAF failures can manifest as current leakage, intermittent electrical shorts, and even dielectric breakdown between conductors in printed circuit boards. This... | 7 | Physical Chemistry |
* Shakiness
* Dry cough
* Dizziness and light-headedness due to low blood pressure
* Fatigue, especially in the early stages
* Mouth dryness in the early stages
* Nausea
* Fainting
* Signs of infection (e.g., fever, chills, persistent sore throat)
* Chest pain
* Neutropenia (low white blood cells)
* Impotence (erectile... | 4 | Stereochemistry |
Historically, flammable, inflammable and combustible meant capable of burning. The word "inflammable" came through French from the Latin inflammāre = "to set fire to", where the Latin preposition "in-" means "in" as in "indoctrinate", rather than "not" as in "invisible" and "ineligible".
The word "inflammable" may be e... | 7 | Physical Chemistry |
Two main subunits of PSI, PsaA and PsaB, are closely related proteins involved in the binding of the vital electron transfer cofactors P, Acc, A, A, and F. PsaA and PsaB are both integral membrane proteins of 730 to 750 amino acids that contain 11 transmembrane segments. A [[4Fe-4S|[4Fe-4S] iron-sulfur cluster]] called... | 5 | Photochemistry |
A risk for periphyton stems from urbanization. Increased turbidity levels associated with urban sprawl can smother periphyton causing its detachment from the rocks on which it lives. It can be important for the clearance of harmful chemicals and reducing turbidity. | 2 | Environmental Chemistry |
*[https://i-aps.org Inter-American Photochemical Society]
*[https://www.photochemistry.eu European Photochemistry Association]
*Asian and Oceanian Photochemistry Association | 5 | Photochemistry |
When a melt undergoes cooling along the liquid line of descent, the results are limited to the production of a homogeneous solid body of intrusive rock, with uniform mineralogy and composition, or a partially differentiated cumulate mass with layers, compositional zones and so on. This behaviour is fairly predictable a... | 9 | Geochemistry |
The Serine-Histidine-Aspartate motif is one of the most thoroughly characterised catalytic motifs in biochemistry. The triad is exemplified by chymotrypsin, a model serine protease from the PA superfamily which uses its triad to hydrolyse protein backbones. The aspartate is hydrogen bonded to the histidine, increasing ... | 1 | Biochemistry |
Common high-activity activators are mineral acids, often together with halides, amines, water or alcohols:
* hydrochloric acid, most common
* phosphoric acid, less common, use limited by its polymerization at higher temperatures
Inorganic acids are highly corrosive to metals even at room temperature, which causes issue... | 8 | Metallurgy |
Trace amounts of up to 16 µg·m have been detected in tobacco smoke.
Minor amounts of pyridine are released into environment from some industrial processes such as steel manufacture, processing of oil shale, coal gasification, coking plants and incinerators. The atmosphere at oil shale processing plants can contain pyr... | 0 | Organic Chemistry |
eIF2 is a heterotrimer of a total molar mass of 126 kDa that is composed of the three sub-units: α (sub-unit 1), β (sub-unit 2), and γ (sub-unit 3).
The sequences of all three sub-units are highly conserved (pairwise amino acid identities for each sub-unit range from 47 to 72% when comparing the proteins of Homo sapie... | 1 | Biochemistry |
We will present a simplified version of the calculation. It differs from the full calculation in three ways:
# The ideal gas consists of particles confined to one spatial dimension.
# We keep only the terms of order , dropping all terms of size n or less, where n is the number of particles. For our purposes, this is ... | 7 | Physical Chemistry |
* Institute of Organoelement Compounds. A. N. Nesmeyanov RAS. In front of Institute building a memorial bust was installed (sculptor Oleg Komov). At the Institute of the annual annual day of memory of A. N. Nesmeyanov with relatives and graduate students.
* On September 26, 1980, one of the streets of the Gagarinsky di... | 0 | Organic Chemistry |
Fick's first law relates the diffusive flux to the gradient of the concentration. It postulates that the flux goes from regions of high concentration to regions of low concentration, with a magnitude that is proportional to the concentration gradient (spatial derivative), or in simplistic terms the concept that a solut... | 7 | Physical Chemistry |
In this approach, the sample is spiked with a species (internal standard) which is used to normalise the response of analyte, compensating for variables at any stage of the sample preparation and analysis, including ion suppression.
It is important that the internal standard displays very similar (ideally identical) pr... | 3 | Analytical Chemistry |
In the diagram on the right, phytoplankton convert CO, which has dissolved from the atmosphere into the surface oceans (90 Gt yr), into particulate organic carbon (POC) during primary production (~ 50 Gt C yr). Phytoplankton are then consumed by copepods, krill and other small zooplankton grazers, which in turn are pre... | 9 | Geochemistry |
10-acetyl-3,7-dihydroxyphenoxazine (also known as Amplex Red), structurally related to resazurin, reacts with HO in a 1:1 stoichiometry to produce the same by-product resorufin (used in many assays combining for example horseradish peroxidase (HRP), or NADH, NADPH using enzymes).
7-ethoxyresorufin, a compound used as t... | 3 | Analytical Chemistry |
Thermal radiation is electromagnetic radiation emitted by the thermal motion of particles in matter. Thermal radiation transmits as an electromagnetic wave through both matter and vacuum. When matter absorbs thermal radiation its temperature will tend to rise. All matter with a temperature greater than absolute zero em... | 7 | Physical Chemistry |
Recently, a nickel-catalyzed Sonogashira coupling has been developed which allows for the coupling of non-activated alkyl halides to acetylene without the use of palladium, although a copper co-catalyst is still needed. It has also been reported that gold can be used as a heterogeneous catalyst, which was demonstrated ... | 0 | Organic Chemistry |
Melt spinning is used to manufacture thin metal sheets or ribbons that are near amorphous or non-crystalline. The unique resulting electric and magnetic properties of melt-spun metals are a consequence of this structure as well as the composition of the alloy or metal that was used to form the ribbon. | 8 | Metallurgy |
Cram expanded upon Charles Pedersens ground-breaking synthesis of crown ethers, two-dimensional organic compounds that are able to recognize and selectively combine with the ions of certain metal elements. He synthesized molecules that took this chemistry into three dimensions, creating an array of differently shaped m... | 4 | Stereochemistry |
Twinning is a form of symmetrical intergrowth between two or more adjacent crystals of the same mineral. It differs from the ordinary random intergrowth of mineral grains in a mineral deposit, because the relative orientations of the two crystal segments show a fixed relationship that is characteristic of the mineral s... | 3 | Analytical Chemistry |
Many enzymes and proteins play a role in degrading mRNA. For example, in Escherichia coli there are three enzymes: RNase II, PNPase, and RNase R. RNase R is a 3’-5’ exoribonuclease that is recruited to degrade a defective mRNA. RNase R has two structural domains, an N-terminal putative helix-turn-helix (HTH) and a C-te... | 1 | Biochemistry |
The human body has many defense mechanisms against pathogens, one of which is humoral immunity. This defence mechanism produces antibodies (large glycoproteins) in response to an immune stimulus. Many cells of the immune system are required for this process, including lymphocytes (T-cells and B-cells) and antigen prese... | 1 | Biochemistry |
The U.S. Bureau of Mines (USBM), developed by Donaldson et al. in 1969, is a method to measure wettability of petroleum reservoir rocks. In this method, the areas under the forced displacement Capillary pressure curves of oil and water drive processes are denoted as and to calculate the USBM index.
USBM index is pos... | 7 | Physical Chemistry |
The van der Waals radius, r, of an atom is the radius of an imaginary hard sphere representing the distance of closest approach for another atom.
It is named after Johannes Diderik van der Waals, winner of the 1910 Nobel Prize in Physics, as he was the first to recognise that atoms were not simply points and to demons... | 6 | Supramolecular Chemistry |
In order to find theoretically the deuterium magnetic dipole moment μ, one uses the formula for a nuclear magnetic moment
with
g and g are g-factors of the nucleons.
Since the proton and neutron have different values for g and g, one must separate their contributions. Each gets half of the deuterium orbital angular mom... | 9 | Geochemistry |
P. Sikivie and Q. Yang showed that cold dark matter axions would form a Bose–Einstein condensate by thermalisation because of gravitational self-interactions. Axions have not yet been confirmed to exist. However the important search for them has been greatly enhanced with the completion of upgrades to the Axion Dark Ma... | 7 | Physical Chemistry |
Minze Stuiver was born in Vlagtwedde, the Netherlands, on 25 October 1929. As a boy he narrowly missed being taken into German forced labor toward the end of the Second World War, but, because he was away delivering milk by bicycle, he escaped the round-up that took most of the young men and older boys from the villag... | 9 | Geochemistry |
See Vitamin, Mineral (nutrient), Protein (nutrient)
An inadequate amount of a nutrient is a deficiency. Deficiencies can be due to a number of causes including an inadequacy in nutrient intake, called a dietary deficiency, or any of several conditions that interfere with the utilization of a nutrient within an organism... | 9 | Geochemistry |
The MODAL strategy defines overlap sequences known as "linkers" to reduce the amount of customisation that needs to be done with each DNA fragment. The linkers were designed using the [https://omictools.com/r2odna-designer-tool R2oDNA Designer] software and the overlap regions were designed to be 45 bp long to be compa... | 1 | Biochemistry |
The complex is the simplest PPC appearing in nature and therefore a suitable test object for the development of methods that can be transferred to more complex systems like photosystem I. Engel and co-workers observed that the FMO complex exhibits remarkably long quantum coherence, but after about a decade of debate, ... | 5 | Photochemistry |
Nevado was born in Madrid and grew up in Spain. She was the first scientist in her family. At high school she was inspired by her chemistry and physics teachers to pursue a career in science. She eventually studied chemistry at the Autonomous University of Madrid, and earned her bachelor's degree in 2000. During one su... | 0 | Organic Chemistry |
As the study of isochores was de facto abandoned by most scientists, an alternative theory was proposed to describe the compositional organization of genomes in accordance with the most recent genomic studies. The Compositional Domain Model depicts genomes as a medley of short and long homogeneous and nonhomogeneous do... | 1 | Biochemistry |
Eco pickled surface (EPS) is a process applied to hot rolled sheet steel to remove all surface oxides (mill scale) and clean the steel surface. Steel which has undergone the EPS process acquires a high degree of resistance to subsequent development of surface oxide (rust), so long as it does not come into direct contac... | 8 | Metallurgy |
A missense mRNA arises from a missense mutation, in the event of which a DNA nucleotide base pair in the coding region of a gene is changed such that it results in the substitution of one amino acid for another. The point mutation is nonsynonymous because it alters the RNA codon in the mRNA transcript such that transla... | 1 | Biochemistry |
Starfish is a set of software tools developed in 2019 by a consortium of scientists to analyze data from nine different variations of FISH, since all variations produce the same set of data—gene expression values mapped to x and y coordinates in a cell. The software, created for all scientists, not just bioinformaticia... | 1 | Biochemistry |
Sandra Pizzarello's research over the last forty years involved the analysis of organic compounds in several carbonaceous chondrites, particularly molecular, chiral, and isotopic characterization of amino acids. Because the formation of these organic-rich meteorites pre-date the origin of life, they had been under inve... | 1 | Biochemistry |
The injection valve is a motorized valve which links the mixer and sample loop to the column. Typically the valve has three positions for loading the sample loop, for injecting the sample from the loop into the column, and for connecting the pumps directly to the waste line to wash them or change buffer solutions. The ... | 3 | Analytical Chemistry |
Complementarity can be found between short nucleic acid stretches and a coding region or a transcribed gene, and results in base pairing. These short nucleic acid sequences are commonly found in nature and have regulatory functions such as gene silencing. | 1 | Biochemistry |
Technicon published method sheets for a wide range of analyses and a few of these are listed below. These methods and later methods are available from SEAL Analytical. Method lists for manufacturers instruments are readily available on their websites. | 3 | Analytical Chemistry |
Coronavir is the brand name of favipiravir used in Russia, where it is approved for the treatment of COVID-19. It is produced and sold by R-Pharm. Coronavir was approved for use in Russia in hospitals in July 2020, and in September 2020 it received approval for prescription sales for outpatient use. | 4 | Stereochemistry |
mTOR promotes the protein synthesis required for synaptic plasticity. Studies in cell cultures and hippocampal slices indicate that mTOR inhibition reduces long-term potentiation. mTOR activation can protect against certain neurodegeneration associated with certain disease conditions. On the other hand, promotion of au... | 1 | Biochemistry |
Haloalkanes are a class of molecule that is defined by a carbon–halogen bond. This bond can be relatively weak (in the case of an iodoalkane) or quite stable (as in the case of a fluoroalkane). In general, with the exception of fluorinated compounds, haloalkanes readily undergo nucleophilic substitution reactions or el... | 0 | Organic Chemistry |
In the synthesis of spirotryprostatin B, an azomethine ylide is formed from condensation of an amine with an aldehyde. The ylide then reacts with an electron-deficient alkene on an indolinone, resulting in formation of a spirocyclic pyrrolidine and four contiguous stereocenters. | 0 | Organic Chemistry |
Sulfonyl halide groups occur when a sulfonyl functional group is singly bonded to a halogen atom. They have the general formula R−SO−X where X is a halide, usually chloride or fluoride. Chlorides are produced by chlorination of sulfonic acids using thionyl chloride. Sulfonyl fluorides can be produced by treating sulfon... | 0 | Organic Chemistry |
Isolated restriction enzymes are used to manipulate DNA for different scientific applications.
They are used to assist insertion of genes into plasmid vectors during gene cloning and protein production experiments. For optimal use, plasmids that are commonly used for gene cloning are modified to include a short polylin... | 1 | Biochemistry |
The GC-ratio within a genome is found to be markedly variable. These variations in GC-ratio within the genomes of more complex organisms result in a mosaic-like formation with islet regions called isochores. This results in the variations in staining intensity in chromosomes. GC-rich isochores typically include many pr... | 1 | Biochemistry |
The process of electrochlorination is a simple application based on the chloralkali process (in an unpartitioned cell).
It is the electrolysis of saltwater to produce a chlorinated solution. The first step is removing any solids from the saltwater. Next, the saltwater streams through an electrolyzer cell's channel of ... | 7 | Physical Chemistry |
Before powered fans were widely accessible, their use related to the social divide between social classes. In Britain and China, they were initially only installed in the buildings of Parliament and in noble homes. In Ancient Egypt (3150 BC), servants were required to fan Pharaohs and important figures.
In parts of the... | 7 | Physical Chemistry |
Through the seasonal vertical migration of zooplankton, the lipid pump creates a net difference between lipids transported to the deep during the fall (when zooplankton enter diapause) and what returns to the surface during the spring, resulting in the sequestration of lipid carbon at depth. The biological pump encompa... | 9 | Geochemistry |
Formaldehyde can be determined in electroless copper plating solutions by the addition of an excess of sodium sulfite solution and titrating the liberated hydroxyl ion with standard acid.
: HC=O + HSO + HO → [HO-CH-SO] + OH | 3 | Analytical Chemistry |
Articles made of Corinthian bronze are mentioned in the Bible. The Beautiful Gate (or Nicanor Gate) of the Second Temple in Jerusalem, mentioned in the Book of Acts 3:2–10, was a large, 18 metre (60 feet) wide structure said to be either solid, or covered in plates of, Corinthian brass. Another Biblical reference, in B... | 8 | Metallurgy |
Metal pollution in soil will induce high toxicity in hemp plants. Cadmium (Cd) toxicity has been proven to be long term and irreversible in plants. Cd specifically results in oxidative stress and increase in free radicals. Free radicals are found to cause oxidative stress, cell damage, and death. Hemp plants in Cd poll... | 1 | Biochemistry |
The first rule holds that a double-stranded DNA molecule, globally has percentage base pair equality: A% = T% and G% = C%. The rigorous validation of the rule constitutes the basis of Watson–Crick base pairs in the DNA double helix model. | 1 | Biochemistry |
The exact mechanism of the action of general anaesthetics has not been delineated. Halothane activates GABA and glycine receptors. It also acts as an NMDA receptor antagonist, inhibits nACh and voltage-gated sodium channels, and activates 5-HT and twin-pore K channels. It does not affect the AMPA or kainate receptors. | 4 | Stereochemistry |
Phorbol is a natural product found in many plants, especially those of the Euphorbiaceae and Thymelaeaceae families. Phorbol is the active constituent of the highly toxic New World tropical manchineel or beach apple, Hippomane mancinella. It is very soluble in most polar organic solvents, as well as in water. In the m... | 0 | Organic Chemistry |
Triethyloxonium tetrafluoroborate is the organic oxonium compound with the formula . It is often called Meerweins reagent or Meerweins salt after its discoverer Hans Meerwein. Also well known and commercially available is the related trimethyloxonium tetrafluoroborate. The compounds are white solids that dissolve in po... | 0 | Organic Chemistry |
The protein encoded by this gene mediates transcriptional control by interaction with the activation function 2 (AF2) region of several nuclear receptors, including the estrogen, retinoic acid, and vitamin D receptors. The protein localizes to nuclear bodies and is thought to associate with chromatin and heterochromati... | 1 | Biochemistry |
Transcription elongation is not a smooth ride along double stranded DNA, as RNA polymerase undergoes extensive co-transcriptional pausing during transcription elongation. In general, RNA polymerase II does not transcribe through a gene at a constant pace. Rather it pauses periodically at certain sequences, sometimes fo... | 1 | Biochemistry |
Advantages of electrofusion welding:
* Simple process capable of producing consistent joints
* Process is entirely contained, reducing the risk of joint contamination
* Process allows repair without the need to remove pipes
Disadvantages of electrofusion welding:
* A special sleeve is required, so it is more expensive... | 7 | Physical Chemistry |
Arsenical bronze has seen little use in the modern period. It appears that the closest equivalent goes by the name of arsenical copper, defined as copper with under 0.5 wt% As, below the accepted percentage in archaeological artefacts. The presence of 0.5 wt% arsenic in copper lowers the electrical conductivity to 34% ... | 8 | Metallurgy |
Although CoQ has been used to treat purported muscle-related side effects of statin medications, a 2015 meta-analysis found that CoQ had no effect on statin myopathy. A 2018 meta-analysis concluded that there was preliminary evidence for oral CoQ reducing statin-associated muscle symptoms, including muscle pain, muscle... | 1 | Biochemistry |
Some enzymatic nitrification inhibitors, such as nitrapyrin, can also inhibit the oxidation of methane in methanotrophic bacteria. AMO shows similar kinetic turnover rates to methane monooxygenase (MMO) found in methanotrophs, indicating that MMO is a similar catalyst to AMO for the purpose of methane oxidation. Furthe... | 1 | Biochemistry |
The inducer in the lac operon is allolactose. If lactose is present in the medium, then a small amount of it will be converted to allolactose by a few molecules of β-galactosidase that are present in the cell. Allolactose binds to the repressor and decreases the repressor's affinity for the operator site.
However, when... | 0 | Organic Chemistry |
Metal nitrosyls, compounds featuring NO ligands, are numerous. In contrast to metal carbonyls, however, homoleptic metal nitrosyls are rare. NO is a stronger π-acceptor than CO. Well known nitrosyl carbonyls include CoNO(CO) and Fe(NO)(CO), which are analogues of Ni(CO). | 0 | Organic Chemistry |
Efforts are reported in asymmetric synthesis of halo carbonyls through organocatalysis. In one study an acid chloride is converted into an α-halo ester with a strong base (sodium hydride), a bromine donor and an organocatalyst based on proline and quinine:
In the proposed reaction mechanism the base first converts the ... | 0 | Organic Chemistry |
Reaction centers are multi-protein complexes found within the thylakoid membrane.
At the heart of a photosystem lies the reaction center, which is an enzyme that uses light to reduce and oxidize molecules (give off and take up electrons). This reaction center is surrounded by light-harvesting complexes that enhance the... | 5 | Photochemistry |
Airborne Real-time Cueing Hyperspectral Enhanced Reconnaissance, also known by the acronym ARCHER, is an aerial imaging system that produces ground images far more detailed than plain sight or ordinary aerial photography can.
It is the most sophisticated unclassified hyperspectral imaging system available, according to... | 7 | Physical Chemistry |
Hydroamination has been examined with a variety of amines, unsaturated substrates, and vastly different catalysts. Amines that have been investigated span a wide scope including primary, secondary, cyclic, acyclic, and anilines with diverse steric and electronic substituents. The unsaturated substrates that have been i... | 0 | Organic Chemistry |
A rock hyrax midden is a stratified accumulation of fecal pellets and a brown amber-like a urinary product known as hyraceum excreted by the rock hyrax and closely related species.
Hyrax middens form very slowly (ranging from ~5 years to >1000 years for 1 mm of hyraceum accumulation), over long periods of time, with ... | 9 | Geochemistry |
In the case catalytic or adsorbent systems where a metal species is dispersed upon a support (or carrier) material (often quasi-inert oxides, such as alumina or silica), it is possible for an adsorptive species to indirectly adsorb to the support surface under conditions where such adsorption is thermodynamically unfav... | 7 | Physical Chemistry |
Members of the Hedgehog protein family act by binding to a transmembrane "Patched" receptor, which is bound to the "Smoothened" protein, by which the Hedgehog signal can be transduced. In the absence of Hedgehog, the Patched receptor inhibits Smoothened action. Inhibition of Smoothened causes the Cubitus interruptus (C... | 1 | Biochemistry |
PCBs are fairly chemically unreactive, this property being attractive for its application as an inert material. They resist oxidation.
Many chemical compounds are available to destroy or reduce the PCBs. Commonly, PCBs are degraded by basic mixtures of glycols, which displace some or all chloride. Also effective are re... | 2 | Environmental Chemistry |
An experimental iodine clock sequence has also been established for a system consisting of iodine potassium-iodide, sodium chlorate and perchloric acid that takes place through the following reactions.
Triiodide is present in equilibrium with iodide anion and molecular iodine:
Chlorate ion oxidizes iodide ion to hypoio... | 7 | Physical Chemistry |
In chemistry, conformational isomerism is a form of stereoisomerism in which the isomers can be interconverted just by rotations about formally single bonds (refer to figure on single bond rotation). While any two arrangements of atoms in a molecule that differ by rotation about single bonds can be referred to as diffe... | 4 | Stereochemistry |
Plasmids are the most-commonly used bacterial cloning vectors. These cloning vectors contain a site that allows DNA fragments to be inserted, for example a multiple cloning site or polylinker which has several commonly used restriction sites to which DNA fragments may be ligated. After the gene of interest is inserted,... | 1 | Biochemistry |
*Heat treatment − Treating food with heat, such as blanching or roasting, de-naturates enzymes and destroys the reactants responsible for browning. Blanching is used, for example, in winemaking, tea processing, storing nuts and bacon, and preparing vegetables for freezing preservation. Meat is often partially browned u... | 1 | Biochemistry |
Temperature programmed desorption (TPD) is one of the most widely used surface analysis techniques available for materials research science. It has several applications such as knowing the desorption rates and binding energies of chemical compounds and elements, evaluation of active sites on catalyst surfaces and the u... | 7 | Physical Chemistry |
Thioamides are also a class of drugs that are used to control thyrotoxicosis.
Thioamides have been incorporated into peptides as isosteres for the amide bond. Peptide modifications are analogues of the native peptide, which can reveal the structure-activity relationship (SAR). Analogues of peptides can also be used as... | 0 | Organic Chemistry |
When an isosbestic plot is constructed by the superposition of the absorption spectra of two species (whether by using molar absorptivity for the representation, or by using absorbance and keeping the same molar concentration for both species), the isosbestic point corresponds to a wavelength at which these spectra cro... | 7 | Physical Chemistry |
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