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Ampicillin is an antibiotic belonging to the aminopenicillin class of the penicillin family. The drug is used to prevent and treat a number of bacterial infections, such as respiratory tract infections, urinary tract infections, meningitis, salmonellosis, and endocarditis. It may also be used to prevent group B strepto... | 4 | Stereochemistry |
Many CF-containing metal complexes have been prepared, and some are useful for trifluoromethylation. The most obvious reagent is CFLi, which can be generated by lithium-iodide exchange. This compound is however unstable even at low temperatures. It degrades to lithium fluoride and difluorocarbene. Trifluoromethyl co... | 0 | Organic Chemistry |
1,1,2-Trichloro-1,2,2-trifluoroethane, also called trichlorotrifluoroethane (often abbreviated as TCTFE) or CFC-113, is a chlorofluorocarbon. It has the formula . This colorless, volatile liquid is a versatile solvent. | 2 | Environmental Chemistry |
Enantiomers of a chiral drug often interact in an enantioselective way in a chiral environment. This may be offered by different biotic substances (viz. proteins, nucleic acids, phospholipids and oligosaccharides). They are made up of chiral building blocks that are put together in space in handed conformations. These ... | 4 | Stereochemistry |
Cholesterol uptake by cells instigates inflammation, affecting both the central nervous system and the peripheral systems. This phenomenon involves the aggregation of inflammatory proteins. For instance, in the context of TLR4, cholesterol prompts receptor dimerization. Similarly, with TNF alpha, the substrate facilita... | 1 | Biochemistry |
A sand bath is a common piece of laboratory equipment made from a container filled with heated sand. It is used to evenly heat another container, most often during a chemical reaction.
A sand bath is most commonly used in conjunction with a hot plate or heating mantle. A beaker is filled with sand or metal pellets (c... | 7 | Physical Chemistry |
The carrier gas is sent through the central channel and into the very hot plasma. The sample is then exposed to radio frequency which converts the gas into a plasma. The high temperature of the plasma is sufficient to cause a very large portion of the sample to form ions. This fraction of ionization can approach 100% f... | 3 | Analytical Chemistry |
Histone acetylation and deacetylation are the processes by which the lysine residues within the N-terminal tail protruding from the histone core of the nucleosome are acetylated and deacetylated as part of gene regulation.
Histone acetylation and deacetylation are essential parts of gene regulation. These reactions ar... | 0 | Organic Chemistry |
Terfenol-D, an alloy of the formula (x ≈ 0.3), is a magnetostrictive material. It was initially developed in the 1970s by the Naval Ordnance Laboratory in the United States. The technology for manufacturing the material efficiently was developed in the 1980s at Ames Laboratory under a U.S. Navy-funded program. It is n... | 8 | Metallurgy |
SPE is in fact a method of chromatography, in the sense of having a mobile phase, carrying mixtures through a stationary phase, packed inside a column. The chromatographic process is harnessed to create a solid-liquid extractive technique—allowing separation of a mixture of components by taking advantage of large diffe... | 3 | Analytical Chemistry |
The borax method of gold extraction has been used by artisanal gold miners in the Benguet area north of Manila in the Philippines for more than 30 years. Some believe it was in practice as early as the 1900s. The method is increasingly being seen as a safe alternative to the widespread use of toxic mercury in artisana... | 8 | Metallurgy |
Common cutting agents:
* Sugar: Brix refractometers are used to determine sugar content. Traditional handheld refractometers are cheap and can be used to measure whole percentages. Digital handheld refractometers are used to determine percentages in decimal values. | 3 | Analytical Chemistry |
An alternative method for analyzing the autocorrelation function can be achieved through an inverse Laplace transform known as CONTIN developed by Steven Provencher. The CONTIN analysis is ideal for heterodisperse, polydisperse, and multimodal systems that cannot be resolved with the cumulant method. The resolution for... | 7 | Physical Chemistry |
Recent research suggests that patients with elevated basal levels of CRP are at an increased risk of diabetes, hypertension and cardiovascular disease. A study of over 700 nurses showed that those in the highest quartile of trans fat consumption had blood levels of CRP that were 73% higher than those in the lowest quar... | 1 | Biochemistry |
Degenerate gases are gases composed of fermions such as electrons, protons, and neutrons rather than molecules of ordinary matter. The electron gas in ordinary metals and in the interior of white dwarfs are two examples. Following the Pauli exclusion principle, there can be only one fermion occupying each quantum state... | 7 | Physical Chemistry |
The crushed ore is irrigated with a dilute alkaline cyanide solution. The solution containing the dissolved precious metals in a pregnant solution continues percolating through the crushed ore until it reaches the liner at the bottom of the heap where it drains into a storage (pregnant solution) pond. After separating ... | 8 | Metallurgy |
Dimethylaminomethylene cation is described as a resonance hybrid of the carbocation and an iminium cation:
The atoms are coplanar. The cation is isoelectronic with isobutene. | 0 | Organic Chemistry |
In addition to the use of the multiprotein complexes listed above, gram-negative bacteria possess another method for release of material: the formation of outer membrane vesicles. Portions of the outer membrane pinch off, forming spherical structures made of a lipid bilayer enclosing periplasmic materials. Vesicles f... | 1 | Biochemistry |
Hydrophilic solids, which include many solids of biological origin, can readily absorb water. Polar interactions between water and the molecules of the solid favor partition of the water into the solid, which can allow significant absorption of water vapor even in relatively low humidity. | 7 | Physical Chemistry |
Because many polymers are composed of primarily of hydrocarbon chains with at most slightly polar functional groups, they tend to have low surface energies and thus adsorb rather poorly. While this can be advantageous for some applications, modification of polymer surfaces is crucial for many other applications in whic... | 7 | Physical Chemistry |
DNA fragmentation is often necessary prior to library construction or subcloning for DNA sequences. A variety of methods involving the mechanical breakage of DNA have been employed where DNA is fragmented by laboratory personnel. Such methods include sonication, needle shear, nebulisation, point-sink shearing and passa... | 1 | Biochemistry |
A bioindicator is any species (an indicator species) or group of species whose function, population, or status can reveal the qualitative status of the environment. The most common indicator species are animals. For example, copepods and other small water crustaceans that are present in many water bodies can be monitor... | 2 | Environmental Chemistry |
The biosphere is 22% oxygen by volume, present mainly as a component of organic molecules (CHNO) and water. | 5 | Photochemistry |
The vortex tube, also known as the Ranque-Hilsch vortex tube, is a mechanical device that separates a compressed gas into hot and cold streams. The gas emerging from the hot end can reach temperatures of , and the gas emerging from the cold end can reach . It has no moving parts and is considered an environmentally fri... | 7 | Physical Chemistry |
The rocks on the plains of Gusev are a type of basalt. They contain the minerals olivine, pyroxene, plagioclase, and magnetite, and they look like volcanic basalt as they are fine-grained with irregular holes (geologists would say they have vesicles and vugs).
Much of the soil on the plains came from the breakdown of ... | 9 | Geochemistry |
There are three molecules that serve as chelator agents that bond to arsenic. These three are British Anti-Lewisite (BAL, Dimercaprol), succimer (DMSA) and Unithiol (DMPS).
When these agents chelate inorganic arsenic, it is converted into an organic form of arsenic because it is bound to the organic chelating agent. Th... | 1 | Biochemistry |
Willard's research interests focused on analytical chemistry and quantitative analysis of inorganic substances. With student G. Frederick Smith, he was particularly productive in studying perchloric acid and periodic acid salts. In addition, he is credited with important work in determining precise atomic weights of ch... | 3 | Analytical Chemistry |
Most floral VOCs belong to three main chemical classes. VOCs in the same chemical class are synthesized from a shared precursor, but the biochemical pathway is specific for each VOC and often varies from one plant species to another.
Terpenoids (or isoprenoids) are derived from isoprene and synthesized via the mevalona... | 1 | Biochemistry |
A sample of cells, either derived from an in vitro cell culture or from an in vivo test subject is dispersed into individual cells and suspended in molten low-melting-point agarose at 37 °C. This mono-suspension is cast on a microscope slide. A glass cover slip is held at an angle and the mono-suspension is applied to ... | 1 | Biochemistry |
In 2003, ATSDR released public health assessments that evaluated the potential health effects of pollution left behind by the United States Navy in Vieques, Puerto Rico. The public health assessments noted that residents of the island were exposed to environmental contamination at such low levels that no harmful health... | 1 | Biochemistry |
Deoxycytidine triphosphate (dCTP) is a nucleoside triphosphate that contains the pyrimidine base cytosine. The triphosphate group contains high-energy phosphoanhydride bonds, which liberate energy when hydrolized.
DNA polymerase enzymes use this energy to incorporate deoxycytidine into a newly synthesized strand of DN... | 1 | Biochemistry |
Cannabinoidergic, or cannabinergic, means "working on the endocannabinoid neurotransmitters". As with terms such as dopaminergic and serotonergic, related proteins and cellular components involved endocannabinoid signaling, such as the cannabinoid (CB) receptor, as well as exogenous compounds, such as phytocannabinoid... | 1 | Biochemistry |
The extent of boiling-point elevation can be calculated by applying Clausius–Clapeyron relation and Raoult's law together with the assumption of the non-volatility of the solute. The result is that in dilute ideal solutions, the extent of boiling-point elevation is directly proportional to the molal concentration (amou... | 7 | Physical Chemistry |
A widely publicized study suggested that humans can detect more than one trillion different odors. This finding has been disputed. Critics argued that the methodology used for the estimation was fundamentally flawed, showing that applying the same argument for better-understood sensory modalities, such as vision or aud... | 1 | Biochemistry |
The term was used as early as 1973, when scientist Carl Sagan described it and other human chauvinisms that limit imagination of possible extraterrestrial life. It suggests that human beings, as carbon-based life forms who have never encountered any life that has evolved outside the Earth's environment, may find it dif... | 1 | Biochemistry |
Crystallographic features of HCP systems, such as vectors and atomic plane families, can be described using a four-value Miller index notation ( hkil ) in which the third index i denotes a convenient but degenerate component which is equal to −h − k. The h, i and k index directions are separated by 120°, and are thus n... | 3 | Analytical Chemistry |
In particle tracking, the trajectories of a set of particles are measured, typically by applying particle tracking algorithms to movies.[http://www.physics.emory.edu/~weeks/idl/] Particle tracking has the advantage that all the dynamical information is maintained in the measurement, unlike FCS where correlation average... | 7 | Physical Chemistry |
Besides anchoring cells to the ECM, laminins are also involved in the signalling of cells and other components of the ECM. Even though there is not a general mechanism that applies to all laminins in signalling, there are some common pathways that can be seen in more than one isoform of laminin. For example, the PI3K/A... | 0 | Organic Chemistry |
Absolute size-exclusion chromatography (ASEC) is a technique that couples a light scattering instrument, most commonly multi-angle light scattering (MALS) or another form of static light scattering (SLS), but possibly a dynamic light scattering (DLS) instrument, to a size-exclusion chromatography system for absolute mo... | 1 | Biochemistry |
Many aspects of academic research and industrial research such as in pharmaceuticals, health products, and many others relies on accurate water analysis to identify substances of potential use, to refine those substances and to ensure that when they are manufactured for sale that the chemical composition remains consis... | 9 | Geochemistry |
Junwang Tang, MAE, FRSC and FIMMM, is the Founding Director of Industrial Catalysis Center, and Carbon Neutrality Chair Professor of Materials Chemistry and Catalysis at the Department of Chemical Engineering, Tsinghua University and Visiting Professor at University College London (UCL). He also served as the Director... | 5 | Photochemistry |
Several theoretical models exist to predict the order of duplication and specialisation events, but the actual process is more intertwined and fuzzy (§ Reconstructed enzymes below). On one hand, gene amplification results in an increase in enzyme concentration, and potentially freedom from a restrictive regulation, the... | 1 | Biochemistry |
Galvanic corrosion is an electrochemical process whereby one metal corrodes preferentially to another when both metals are in electrical contact with each other in the presence of an electrolyte, such as moisture and salts. This is because the dissimilar metals have different electrode potentials. The potential differe... | 8 | Metallurgy |
Lisinopril is typically used for the treatment of high blood pressure, congestive heart failure, and diabetic nephropathy and after acute myocardial infarction (heart attack). Lisinopril is part of the ACE inhibitors drug class. Lisinopril is indicated for the treatment of hypertension, adjunctive therapy for heart fai... | 4 | Stereochemistry |
A-values provide another measure of the bulk of substituents. A-values are derived from equilibrium measurements of monosubstituted cyclohexanes. The extent that a substituent favors the equatorial position gives a measure of its bulk. | 4 | Stereochemistry |
In a fluidized-bed roaster, finely ground sulfide concentrates are suspended and oxidized in feedstock bed supported on an air column. As in the suspension roaster, the reaction rates for desulfurization are more rapid than in the older multiple-hearth processes. Fluidized-bed roasters operate under a pressure slightl... | 8 | Metallurgy |
* Endomycetales (yeasts): Candida albicans, Candida cylindracea, Candida melibiosica, Candida parapsilosis, and Candida rugosa. | 1 | Biochemistry |
*The main criticism applied to the yeast two-hybrid screen of protein–protein interactions are the possibility of a high number of false positive (and false negative) identifications. The exact rate of false positive results is not known, but earlier estimates were as high as 70%. This also, partly, explains the often ... | 1 | Biochemistry |
*2001: Outstanding President Prize by The Chinese Academy of Sciences.
*2003–2005: Japan Society for the Promotion of Science (JSPS) Fellowship by Japan Society for the Promotion of Science.
*2008: Young Scientist Award for research on renewable solar energy by The International Association of Catalysis Societies.
*201... | 5 | Photochemistry |
According to Etymology Online, the verb assay means "to try, endeavor, strive, test the quality of"; from Anglo-French assaier, from assai (noun), from Old French essai, "trial". Thus the noun assay means "trial, test of quality, test of character" (from mid-14th century), from Anglo-French assai; and its meaning "anal... | 1 | Biochemistry |
A thermodynamic instrument is any device for the measurement of thermodynamic systems. In order for a thermodynamic parameter or physical quantity to be truly defined, a technique for its measurement must be specified. For example, the ultimate definition of temperature is "what a thermometer reads". The question follo... | 7 | Physical Chemistry |
Silicon wafers are treated with solutions of electronic-grade hydrofluoric acid in water, buffered water, or alcohol. One of the relevant reactions is simply removal of silicon oxides:
:SiO + 4 HF → SiF + 2 HO
The key reaction however is the formation of the hydrosilane functional group.
atomic force microscope ... | 6 | Supramolecular Chemistry |
In earlier years it was thought that apamin was a rather nontoxic compound (LD = 15 mg/kg in mice) compared to the other compounds in bee venom. The current lethal dose values of apamin measured in mice are given below. There are no data known specific for humans.
Intraperitoneal (mouse) LD: 3.8 mg/kg
Subcutaneous (mo... | 1 | Biochemistry |
The austrapede (Tspìng in Navi) is a Pandoran creature that resembles a cross between an ostrich, a pink flamingo and the herbivorous dinosaur Parasaurolophus. The Austrapede has yellow-orange skin with faint purple striping, a long, flat beak, and a flat tail reaching down to its feet. Unlike other Pandoran birds and ... | 1 | Biochemistry |
The Van 't Hoff isotherm can be used to determine the temperature dependence of the Gibbs free energy of reaction for non-standard state reactions at a constant temperature:
where is the Gibbs free energy of reaction under non-standard states at temperature , is the Gibbs free energy for the reaction at , is the ext... | 7 | Physical Chemistry |
Action potentials are most commonly initiated by excitatory postsynaptic potentials from a presynaptic neuron. Typically, neurotransmitter molecules are released by the presynaptic neuron. These neurotransmitters then bind to receptors on the postsynaptic cell. This binding opens various types of ion channels. This ope... | 7 | Physical Chemistry |
The choice of aryl halide or pseudohalide substrate (sp-carbon) is one of the factors that mainly influence the reactivity of the Sonogashira catalytic system. The reactivity of halides is higher towards iodine, and vinyl halides are more reactive than analogous aryl halides. The coupling of aryl iodides proceeds at ro... | 0 | Organic Chemistry |
The Union Carbide (UCC) process, also known as low-pressure oxo process (LPO), relies on a rhodium catalyst dissolved in high-boiling thick oil, a higher molecular weight condensation product of the primary aldehydes, for the hydroformylation of propene. The reaction mixture is separated in a falling film evaporator fr... | 0 | Organic Chemistry |
The first report of the BCCP structure was made by biochemists F. K. Athappilly and W. A. Hendrickson in 1995. It can be thought of as a long β-hairpin structure, with four pairs of antiparallel β-strands that wrap around a central hydrophobic core. The biotinylation motif Met-Lys-Met is located at the tip of the β-hai... | 1 | Biochemistry |
Very hot objects emit UV radiation (see black-body radiation). The Sun emits ultraviolet radiation at all wavelengths, including the extreme ultraviolet where it crosses into X-rays at 10 nm. Extremely hot stars (such as O- and B-type) emit proportionally more UV radiation than the Sun. Sunlight in space at the top of ... | 5 | Photochemistry |
Actaplanin is a complex of broad-spectrum antibiotics made by Actinoplanes bacteria. Research carried out by a group in Eli Lilly and Co. in 1984 identified several actaplanins using high-performance liquid chromatography. Actaplanins A, B, B, B, C and G were shown to be composed of the same peptide core, an amino suga... | 0 | Organic Chemistry |
Two research groups reported trifluoromethylations of diazonium salts in 2013. Goossen reported the preparation of a complex from CuSCN, , and . In contrast, Fu reported the trifluoromethylation using Umemotos reagent (S'-trifluoromethyldibenzothiophenium tetrafluoroborate) and Cu powder (Gattermann-type conditions). ... | 0 | Organic Chemistry |
In 2016, some 90 organizations, representing over US$2.5 trillion of purchasing power, requested that their suppliers disclose information on how they are approaching climate and water risks and opportunities. Data was gathered from over 4,000 suppliers worldwide, who reported over US$12 billion worth of savings from e... | 2 | Environmental Chemistry |
Prenatal virilization of a genetically female fetus can occur when an excessive amount of androgen is produced by the fetal adrenal glands or is present in maternal blood. In the severest form of congenital adrenal hyperplasia, complete masculinization of a genetically female fetus results in an apparently normal male ... | 1 | Biochemistry |
Bioaerosols (short for biological aerosols) are a subcategory of particles released from terrestrial and marine ecosystems into the atmosphere. They consist of both living and non-living components, such as fungi, pollen, bacteria and viruses. Common sources of bioaerosols include soil, water, and sewage.
Bioaerosols a... | 7 | Physical Chemistry |
Chrome Azurol S is a histological dye used in biomedical research.
Chrome Azural S (CAS) is a common spectrophotometric reagent for detection of certain metals like aluminum which can be toxic in excess and can contribute to people with neurodegenerative disorders. CAS is used to provide quantitative and qualitative in... | 1 | Biochemistry |
Excessive dephosphorylation of the membrane ATPases and proton pumps in the gastrointestinal tract leads to higher secretory rates of caustic peptic acids. These result in heartburn and esophagitis. In combination with Helicobacter pylori infection, peptic ulcer disease is caused by the elevated pH dephosphorylation el... | 1 | Biochemistry |
Each instrument used in analytical chemistry has a useful working range. This is the range of concentration (or mass) that can be adequately determined by the instrument, where the instrument provides a useful signal that can be related to the concentration of the analyte.
All instruments have an upper and a lower work... | 3 | Analytical Chemistry |
All living surfaces are decorated with a diverse range of complex molecules, which are key modulators of chemical communications and other functions such as protection, adhesion, infectivity, apoptosis, etc. Functional-Spacer-Lipid (FSL) Kode constructs can be synthesized to mimic the bioactive components present on bi... | 1 | Biochemistry |
The Virtual breakdown mechanism is a concept in the field of electrochemistry. In electrochemical reactions, when the cathode and the anode are close enough to each other (i.e., so-called "nanogap electrochemical cells"), the double layer of the regions from the two electrodes is overlapped, forming a large electric fi... | 7 | Physical Chemistry |
In generic terms, electrochemical potential is the mechanical work done in bringing 1 mole of an ion from a standard state to a specified concentration and electrical potential. According to the IUPAC definition, it is the partial molar Gibbs energy of the substance at the specified electric potential, where the substa... | 7 | Physical Chemistry |
The protein encoded by this gene was initially named CA-related protein because of sequence similarity to other known carbonic anhydrase genes. However, the gene product lacks carbonic anhydrase activity (i.e., the reversible hydration of carbon dioxide). The gene product continues to carry a carbonic anhydrase designa... | 1 | Biochemistry |
Apart from its usage in sensing acids and fluoride anions, PPA has been used in sensing Pd(0) metal by employing allyl chloroformate as a terminating end cap. This has been reported by Phillips and his research group, where they used an allyl formate endcap that stoichiometrically depolymerized within minutes upon its ... | 7 | Physical Chemistry |
Esomeprazole, sold under the brand name Nexium [or Neksium] among others, is a medication which reduces stomach acid. It is used to treat gastroesophageal reflux disease, peptic ulcer disease, and Zollinger–Ellison syndrome. Its effectiveness is similar to that of other proton pump inhibitors (PPIs). It is taken by mou... | 4 | Stereochemistry |
The PEP carboxylase enzyme is present in plants and some types of bacteria, but not in fungi or animals (including humans). The genes vary between organisms, but are strictly conserved around the active and allosteric sites discussed in the mechanism and regulation sections. Tertiary structure of the enzyme is also con... | 5 | Photochemistry |
Casting and forging are traditional metallurgical processing techniques that can be used to generate both polycrystalline and monocrystalline products. Polycrystalline casts offer higher fracture resistance, while monocrystalline casts offer higher creep resistance.
Jet turbine engines employ both crystalline component... | 8 | Metallurgy |
The crossed molecular beam technique was developed by Dudley Herschbach and Yuan T. Lee, for which they were awarded the 1986 Nobel Prize in Chemistry. While the technique was demonstrated in 1953 by Taylor and Datz of Oak Ridge National Laboratory, Herschbach and Lee refined the apparatus and began probing gas-phase ... | 7 | Physical Chemistry |
With primary amines, thionyl chloride gives sulfinylamine derivatives (RNSO), one example being N-sulfinylaniline. Thionyl chloride reacts with primary formamides to form isocyanides and with secondary formamides to give chloroiminium ions; as such a reaction with dimethylformamide will form the Vilsmeier reagent.
By a... | 0 | Organic Chemistry |
The advantage of nanofluidic devices is from its feasibility to be integrated with electronic circuitry. Because they are built using the same manufacturing technology, it is possible to make a nanofluidic system with digital integrated circuit on a single chip. Therefore, the control and manipulation of particles in t... | 7 | Physical Chemistry |
Nuclear reaction analysis (NRA) is a nuclear method of nuclear spectroscopy in materials science to obtain concentration vs. depth distributions for certain target chemical elements in a solid thin film. | 7 | Physical Chemistry |
Lake surface temperatures fluctuate between in winter, and in summer. From 1979 to 2011 annual rainfall was at the lake, and at Cerro La Laguna, the highest part of the catchment. The residence time of water in the lake is therefore 35 ± 6 days assuming homogeneous water mixing. In actuality the lake is strongly ... | 2 | Environmental Chemistry |
Duke University did a study where they dosed a loblolly pine plantation with elevated levels of . The studies showed that the pines did indeed grow faster and stronger. They were also less prone to damage during ice storms, which is a factor that limits loblolly growth farther north. The forest did relatively better du... | 2 | Environmental Chemistry |
All physical and chemical systems in the universe follow the second law of thermodynamics and proceed in a downhill, i.e., exergonic, direction. Thus, left to itself, any physical or chemical system will proceed, according to the second law of thermodynamics, in a direction that tends to lower the free energy of the s... | 7 | Physical Chemistry |
Alkalinity roughly refers to the molar amount of bases in a solution that can be converted to uncharged species by a strong acid. For example, 1 mole of in solution represents 1 molar equivalent, while 1 mole of is 2 molar equivalents because twice as many H ions would be necessary to balance the charge. The total ch... | 9 | Geochemistry |
Sunset yellow is used in foods, condoms, cosmetics, and drugs. Sunset yellow FCF is used as an orange or yellow-orange dye. For example, it is used in candy, desserts, snacks, sauces, and preserved fruits.
Sunset yellow is often used in conjunction with E123, amaranth, to produce a brown colouring in both chocolates a... | 3 | Analytical Chemistry |
The generation of a transmembrane electrical potential through ion movement across a cell membrane drives biological processes like nerve conduction, muscle contraction, hormone secretion, and sensation. By convention, physiological voltages are measured relative to the extracellular region; a typical animal cell has ... | 7 | Physical Chemistry |
The observation of the color of metal-electride solutions is generally attributed to Humphry Davy. In 1807–1809, he examined the addition of grains of potassium to gaseous ammonia (liquefaction of ammonia was invented in 1823). James Ballantyne Hannay and J. Hogarth repeated the experiments with sodium in 1879–1880. W.... | 0 | Organic Chemistry |
Activated GPCRs cause a conformational change in the attached G protein complex, which results in the G alpha subunit's exchanging GDP for GTP and separation from the beta and gamma subunits. The G alpha subunit, in turn, activates adenylyl cyclase, which quickly converts ATP into cAMP. This leads to the activation of ... | 1 | Biochemistry |
Loss-of-function mutations in females can lead to infertility. In 46, XY individuals severe inactivation can cause male pseudohermaphroditism, as fetal Leydig cells during may not respond and thus interfere with masculinization. Less severe inactivation can result in hypospadias or a micropenis. | 1 | Biochemistry |
Many classes of compounds with C–O–C linkages are not considered ethers: Esters (R–C(=O)–O–R′), hemiacetals (R–CH(–OH)–O–R′), carboxylic acid anhydrides (RC(=O)–O–C(=O)R′).
There are compounds which, instead of C in the linkage, contain heavier group 14 chemical elements (e.g., Si, Ge, Sn, Pb). Such compounds are cons... | 0 | Organic Chemistry |
Rhenium and osmium are siderophile elements which are present at very low abundances in the crust. Rhenium undergoes radioactive decay to produce osmium. The ratio of non-radiogenic osmium to radiogenic osmium throughout time varies.
Rhenium prefers to enter sulfides more readily than osmium. Hence, during melting of t... | 9 | Geochemistry |
Arslantepe was first investigated by the French archaeologist Louis Delaporte from 1932 to 1939. From 1946 to 1951 Claude F.A. Schaeffer carried out some soundings.
The first Italian excavations at the site of Arslantepe started in 1961, and were conducted under the direction of Professors Piero Meriggi and Salvatore M... | 8 | Metallurgy |
The existence of discrete inheritable units was first suggested by Gregor Mendel (1822–1884). From 1857 to 1864, in Brno, Austrian Empire (todays Czech Republic), he studied inheritance patterns in 8000 common edible pea plants, tracking distinct traits from parent to offspring. He described these mathematically as 2 c... | 1 | Biochemistry |
Recent research has focused on the in-place remediation of trichloroethylene in soil and groundwater using potassium permanganate instead of removal for off-site treatment and disposal. Naturally occurring bacteria have been identified with the ability to degrade TCE. Dehalococcoides sp. degrade trichloroethylene by re... | 2 | Environmental Chemistry |
In molecular biology, intercellular adhesion molecules (ICAMs) and vascular cell adhesion molecule-1 (VCAM-1) are part of the immunoglobulin superfamily. They are important in inflammation, immune responses and in intracellular signalling events. The ICAM family consists of five members, designated ICAM-1 to ICAM-5. Th... | 1 | Biochemistry |
Blood samples for BAC analysis are typically obtained by taking a venous blood sample from the arm. A variety of methods exist for determining blood-alcohol concentration in a blood sample. Forensic laboratories typically use headspace-gas chromatography combined with mass spectrometry or flame ionization detection, as... | 1 | Biochemistry |
Reductive elimination of square planar complexes can progress through a variety of mechanisms: dissociative, nondissociative, and associative. Similar to octahedral complexes, a dissociative mechanism for square planar complexes initiates with loss of a ligand, generating a three-coordinate intermediate that undergoes ... | 0 | Organic Chemistry |
Self-propulsion is the autonomous displacement of nano-, micro- and macroscopic natural and artificial objects, containing their own means of motion. Self-propulsion is driven mainly by interfacial phenomena. Various mechanisms of self-propelling have been introduced and investigated, which exploited phoretic effects, ... | 7 | Physical Chemistry |
In molecular biology, subcloning is a technique used to move a particular DNA sequence from a parent vector to a destination vector.
Subcloning is not to be confused with molecular cloning, a related technique. | 1 | Biochemistry |
Natta first used polymerization catalysts based on titanium chlorides to polymerize propylene and other 1-alkenes. He discovered that these polymers are crystalline materials and ascribed their crystallinity to a special feature of the polymer structure called stereoregularity.
The concept of stereoregularity in polym... | 7 | Physical Chemistry |
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