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In 2000, negotiations as to the demarcation of the sea had been going on for nearly a decade among all the states bordering it. Whether it was by law a sea, a lake, or an agreed hybrid, the decision would set the demarcation rules and was heavily debated. Access to mineral resources (oil and natural gas), access for fishing, and access to international waters (through Russias Volga river and the canals connecting it to the Black Sea and Baltic Sea) all rest on the negotiations outcome. Access to the Volga is key for market efficiency and economic diversity of the landlocked states of Azerbaijan, Kazakhstan, and Turkmenistan. This concerns Russia as more traffic seeks to use – and at some points congest – its inland waterways. If the body of water is, by law, a sea, many precedents and international treaties oblige free access to foreign vessels. If it is a lake there are no such obligations.
Resolving and improving some environmental issues properly rests on the status and borders issue.
All five Caspian littoral states maintain naval forces on the sea.
According to a treaty signed between Iran and the Soviet Union, the sea is technically a lake and was divided into two sectors (Iranian and Soviet), but the resources (then mainly fish) were commonly shared. The line between the two sectors was considered an international border in a common lake, like Lake Albert. The Soviet sector was sub-divided into the four littoral republics' administrative sectors.
Russia, Kazakhstan, and Azerbaijan have bilateral agreements with each other based on median lines. Because of their use by the three nations, median lines seem to be the most likely method of delineating territory in future agreements. However, Iran insists on a single, multilateral agreement among the five nations (aiming for a one-fifth share). Azerbaijan is at odds with Iran over some of the sea's oil fields. Occasionally, Iranian patrol boats have fired at vessels sent by Azerbaijan for exploration into the disputed region. There are similar tensions between Azerbaijan and Turkmenistan (the latter claims that the former has pumped more oil than agreed from a field, recognized by both parties as shared).
The Caspian littoral states' meeting in 2007 signed an accord that only allows littoral-state flag-bearing ships to enter the sea.
Negotiations among the five states ebbed and flowed, from about 1990 to 2018. Progress was notable in the fourth Caspian Summit held in Astrakhan in 2014. | 1 | Applied and Interdisciplinary Chemistry |
Mutations in complex III-related genes typically manifest as exercise intolerance. Other mutations have been reported to cause septo-optic dysplasia and multisystem disorders. However, mutations in BCS1L, a gene responsible for proper maturation of complex III, can result in Björnstad syndrome and the GRACILE syndrome, which in neonates are lethal conditions that have multisystem and neurologic manifestations typifying severe mitochondrial disorders. The pathogenicity of several mutations has been verified in model systems such as yeast.
The extent to which these various pathologies are due to bioenergetic deficits or overproduction of superoxide is presently unknown. | 1 | Applied and Interdisciplinary Chemistry |
Metallization pressure is the pressure required for a non-metallic chemical element to become a metal. Every material is predicted to turn into a metal if the pressure is high enough, and temperature low enough. Some of these pressures are beyond the reach of diamond anvil cells, and are thus theoretical predictions. Neon has the highest metallization pressure for any element.
The value for phosphorus refers to pressurizing black phosphorus. The value for arsenic refers to pressurizing metastable black arsenic; grey arsenic, the standard state, is already a metallic conductor at standard conditions. No value is known or theoretically predicted for radon. | 0 | Theoretical and Fundamental Chemistry |
Thermate composition is a thermite enriched with a salt-based oxidizer (usually nitrates, e.g., barium nitrate, or peroxides). In contrast with thermites, thermates burn with evolution of flame and gases. The presence of the oxidizer makes the mixture easier to ignite and improves penetration of target by the burning composition, as the evolved gas is projecting the molten slag and providing mechanical agitation. This mechanism makes thermate more suitable than thermite for incendiary purposes and for emergency destruction of sensitive equipment (e.g., cryptographic devices), as thermite's effect is more localized. | 0 | Theoretical and Fundamental Chemistry |
In 1905, both Goldberg and Ullman moved to Technische Hochschule in Berlin. Goldbergs research, along with that of the Ullmann-Goldberg collaborative, was also a part of Germanys synthetic dye industry. Their research helped with the creation of the synthetic alizarin industry, or the process of replacing natural dye obtained from madder. In 1909, Goldberg also collaborated with Hermann Friedman to review German patents under BASF (Badische Anilin und Soda Fabrik) and Bayer & Co. Farbenfabriken, providing notes on preparation for 114 dyes. | 0 | Theoretical and Fundamental Chemistry |
The degree of inactivation by ultraviolet radiation is directly related to the UV dose applied to the water. The dosage, a product of UV light intensity and exposure time, is usually measured in microjoules per square centimeter, or equivalently as microwatt seconds per square centimeter (μW·s/cm) = 10 mW·s/m = 0.01 W·s/m, the latter might be better, giving two-digit values for the ones in this article-->. Dosages for a 90% kill of most bacteria and viruses range between 2,000 and 8,000 μW·s/cm. Larger parasites such as Cryptosporidium require a lower dose for inactivation. As a result, US EPA has accepted UV disinfection as a method for drinking water plants to obtain Cryptosporidium, Giardia or virus inactivation credits. For example, for a 90% reduction of Cryptosporidium, a minimum dose of 2,500 μW·s/cm is required based on EPA's 2006 guidance manual. | 0 | Theoretical and Fundamental Chemistry |
Some conducting materials may pass electrons to form a difference in electrical charge at the joint. This results in a structure similar to a capacitor and creates an attractive electrostatic force between the materials. | 0 | Theoretical and Fundamental Chemistry |
In Arabidopsis, the protein DWF1 plays an enzymatic role in the biosynthesis of brassinosteroids, steroid hormones in plants that are required for growth. An interaction occurs between CaM and DWF1, and DWF1 being unable to bind CaM is unable to produce a regular growth phenotype in plants. Hence, CaM is essential for the DWF1 function in plant growth.
CaM binding proteins are also known to regulate reproductive development in plants. For instance, the CaM-binding protein kinase in tobacco acts as a negative regulator of flowering. However, these CaM-binding protein kinase are also present in the shoot apical meristem of tobacco and a high concentration of these kinases in the meristem causes a delayed transition to flowering in the plant.
S-locus receptor kinase (SRK) is another protein kinase that interacts with CaM. SRK is involved in the self-incompatibility responses involved in pollen-pistil interactions in Brassica.
CaM targets in Arabidopsis are also involved in pollen development and fertilization. Ca transporters are essential for pollen tube growth. Hence, a constant Ca gradient is maintained at the apex of pollen tube for elongation during the process of fertilization. Similarly, CaM is also essential at the pollen tube apex, where its primarily role involves the guidance of the pollen tube growth. | 1 | Applied and Interdisciplinary Chemistry |
Tetramethylguanidine is mainly used as a strong, non-nucleophilic base for alkylations, often as a substitute for the more expensive DBU and DBN. Since it is highly water-soluble, it is easily removed from mixtures in organic solvents. It is also used as a base-catalyst in the production of polyurethane. | 0 | Theoretical and Fundamental Chemistry |
As early as 1996, the Chemical Heritage Foundation had envisioned a broadly-based museum of chemical progress in which instruments would have "a major, but not exclusive role". That vision was followed when Peter Saylor of Dagit•Saylor Architects created the public museum and conference space. The Arnold O. Beckman Permanent Exhibit and the Clifford C. Hach Gallery for rotating exhibitions opened in 2008. The Arnold O. Beckman permanent exhibition, Making Modernity, was designed by Ralph Appelbaum Associates. It has been described as an "art gallery for science", and showcases objects from the institutions widely varying collections. "The instruments are only a fraction of the objects on display. The exhibition also includes books, documents, and artwork from CHFs collection, as well as an array of consumer products." The exhibition is organized around thematic arcs illustrative of the history of science, particularly chemistry. Displays include the influence of alchemy in early chemistry, the development of the first plastics, the development of brilliantly colored synthetic dyes, scientific advocacy for public health in the 19th and 20th centuries, and the teaching of chemistry through books and chemistry sets. | 1 | Applied and Interdisciplinary Chemistry |
Hydrogen cyanide will react with alkenes under catalysis of nickel complexes. This reaction is called hydrocyanation.
:RCH=CH + HCN → RCH-CH-CN
Four molecules of HCN will tetramerize into diaminomaleonitrile, which can be converted to various purines. | 0 | Theoretical and Fundamental Chemistry |
An adatom is an atom that lies on a crystal surface, and can be thought of as the opposite of a surface vacancy. This term is used in surface chemistry and epitaxy, when describing single atoms lying on surfaces and surface roughness. The word is a portmanteau of "adsorbed atom". A single atom, a cluster of atoms, or a molecule or cluster of molecules may all be referred to by the general term "adparticle". This is often a thermodynamically unfavorable state. However, cases such as graphene may provide counter-examples. | 0 | Theoretical and Fundamental Chemistry |
For each thermodynamic potential, there are thermodynamic variables that need to be held constant to specify the potential value at a thermodynamical equilibrium state, such as independent variables for a mathematical function. These variables are termed the natural variables of that potential. The natural variables are important not only to specify the potential value at the equilibrium, but also because if a thermodynamic potential can be determined as a function of its natural variables, all of the thermodynamic properties of the system can be found by taking partial derivatives of that potential with respect to its natural variables and this is true for no other combination of variables. If a thermodynamic potential is not given as a function of its natural variables, it will not, in general, yield all of the thermodynamic properties of the system.
The set of natural variables for each of the above four thermodynamic potentials is formed from a combination of the , , , variables, excluding any pairs of conjugate variables; there is no natural variable set for a potential including the - or - variables together as conjugate variables for energy. An exception for this rule is the − conjugate pairs as there is no reason to ignore these in the thermodynamic potentials, and in fact we may additionally define the four potentials for each species. Using IUPAC notation in which the brackets contain the natural variables (other than the main four), we have:
If there is only one species, then we are done. But, if there are, say, two species, then there will be additional potentials such as and so on. If there are dimensions to the thermodynamic space, then there are unique thermodynamic potentials. For the most simple case, a single phase ideal gas, there will be three dimensions, yielding eight thermodynamic potentials. | 0 | Theoretical and Fundamental Chemistry |
Prokaryotes have a prokaryotic cytoskeleton that is more primitive than that of the eukaryotes. Besides homologues of actin and tubulin (MreB and FtsZ), the helically arranged building-block of the flagellum, flagellin, is one of the most significant cytoskeletal proteins of bacteria, as it provides structural backgrounds of chemotaxis, the basic cell physiological response of bacteria. At least some prokaryotes also contain intracellular structures that can be seen as primitive organelles.
Membranous organelles (or intracellular membranes) are known in some groups of prokaryotes, such as vacuoles or membrane systems devoted to special metabolic properties, such as photosynthesis or chemolithotrophy. In addition, some species also contain carbohydrate-enclosed microcompartments, which have distinct physiological roles (e.g. carboxysomes or gas vacuoles).
Most prokaryotes are between 1 µm and 10 µm, but they can vary in size from 0.2 µm (Mycoplasma genitalium) to 750 µm (Thiomargarita namibiensis). | 1 | Applied and Interdisciplinary Chemistry |
* [https://www.fs.usda.gov/rmrs/air-soil-and-water-resources-and-quality Rocky Mountain Research Station - Air, soil, and water resources and quality]
* [https://www.nimss.org/projects/18621 NRSP3: The National Atmospheric Deposition Program (NADP)] | 1 | Applied and Interdisciplinary Chemistry |
Asbestiform is a crystal habit. It describes a mineral that grows in a fibrous aggregate of high tensile strength, flexible, long, and thin crystals that readily separate. The most common asbestiform mineral is chrysotile, commonly called "white asbestos", a magnesium phyllosilicate part of the serpentine group. Other asbestiform minerals include riebeckite, an amphibole whose fibrous form is known as crocidolite or "blue asbestos", and brown asbestos, a cummingtonite-grunerite solid solution series.
The United States Environmental Protection Agency explains that, "In general, exposure may occur only when the asbestos-containing material is disturbed or damaged in some way to release particles and fibers into the air."
"Mountain leather" is an old-fashioned term for flexible, sheet-like natural formations of asbestiform minerals which resemble leather. Asbestos-containing minerals known to form mountain leather include: actinolite, palygorskite, saponite, sepiolite, tremolite, and zeolite. | 0 | Theoretical and Fundamental Chemistry |
The study of deformation is essential for the development of new materials. Deformation in metals depends on temperature, type of stress applied, strain rate, oxidation, and corrosion. Deformation-induced EMR can be divided into three categories: effects in ionic crystal materials, effects in rocks and granites, and effects in metals and alloys. EMR emission depends on the orientation of the grains in individual crystals since material properties are different in differing directions. Amplitude of the EMR pulse increases as long as the crack grows as new atomic bonds are broken, leading to EMR. The Pulse starts to decay as the cracking halts. Observations from experiments showed that emitted EMR signals contain mixed frequency components. | 0 | Theoretical and Fundamental Chemistry |
In organic chemistry, thioketones (; also known as thiones or thiocarbonyls) are organosulfur compounds related to conventional ketones in which the oxygen has been replaced by a sulfur. Instead of a structure of , thioketones have the structure , which is reflected by the prefix "thio-" in the name of the functional group. Thus the simplest thioketone is thioacetone, the sulfur analog of acetone. Unhindered alkylthioketones typically tend to form polymers or rings. | 0 | Theoretical and Fundamental Chemistry |
The first ideas about light being used in photosynthesis were proposed by Colin Flannery in 1779 who recognized it was sunlight falling on plants that was required, although Joseph Priestley had noted the production of oxygen without the association with light in 1772. Cornelis Van Niel proposed in 1931 that photosynthesis is a case of general mechanism where a photon of light is used to photo decompose a hydrogen donor and the hydrogen being used to reduce .
Then in 1939, Robin Hill demonstrated that isolated chloroplasts would make oxygen, but not fix , showing the light and dark reactions occurred in different places. Although they are referred to as light and dark reactions, both of them take place only in the presence of light. This led later to the discovery of photosystems I and II. | 0 | Theoretical and Fundamental Chemistry |
Soft (or ductile) copper tubing can be bent easily to travel around obstacles in the path of the tubing. While the work hardening of the drawing process used to size the tubing makes the copper hard/rigid, it is carefully annealed to make it soft again; it is therefore more expensive to produce than non-annealed, rigid copper tubing. It can be joined by any of the three methods used for rigid copper, and it is the only type of copper tubing suitable for flare connections. Soft copper is the most popular choice for refrigerant lines in split-system air conditioners and heat pumps. | 1 | Applied and Interdisciplinary Chemistry |
Chemistry education (or chemical education) is the study of teaching and learning chemistry. It is one subset of STEM education or discipline-based education research (DBER). Topics in chemistry education include understanding how students learn chemistry and determining the most efficient methods to teach chemistry. There is a constant need to improve chemistry curricula and learning outcomes based on findings of chemistry education research (CER). Chemistry education can be improved by changing teaching methods and providing appropriate training to chemistry instructors, within many modes, including classroom lectures, demonstrations, and laboratory activities. | 1 | Applied and Interdisciplinary Chemistry |
The normal coordinates, denoted as Q, refer to the positions of atoms away from their equilibrium positions, with respect to a normal mode of vibration. Each normal mode is assigned a single normal coordinate, and so the normal coordinate refers to the "progress" along that normal mode at any given time. Formally, normal modes are determined by solving a secular determinant, and then the normal coordinates (over the normal modes) can be expressed as a summation over the cartesian coordinates (over the atom positions). The normal modes diagonalize the matrix governing the molecular vibrations, so that each normal mode is an independent molecular vibration. If the molecule possesses symmetries, the normal modes "transform as" an irreducible representation under its point group. The normal modes are determined by applying group theory, and projecting the irreducible representation onto the cartesian coordinates. For example, when this treatment is applied to CO, it is found that the C=O stretches are not independent, but rather there is an O=C=O symmetric stretch and an O=C=O asymmetric stretch:
* symmetric stretching: the sum of the two C–O stretching coordinates; the two C–O bond lengths change by the same amount and the carbon atom is stationary. Q = q + q
* asymmetric stretching: the difference of the two C–O stretching coordinates; one C–O bond length increases while the other decreases. Q = q − q
When two or more normal coordinates belong to the same irreducible representation of the molecular point group (colloquially, have the same symmetry) there is "mixing" and the coefficients of the combination cannot be determined a priori. For example, in the linear molecule hydrogen cyanide, HCN, The two stretching vibrations are
* principally C–H stretching with a little C–N stretching; Q = q + a q (a << 1)
* principally C–N stretching with a little C–H stretching; Q = b q + q (b << 1)
The coefficients a and b are found by performing a full normal coordinate analysis by means of the Wilson GF method. | 0 | Theoretical and Fundamental Chemistry |
Transition metal sulfate complexes or sulfato complexes are coordination complexes with one or more sulfate ligands. Sulfate binds to metals through one, two, three, or all four oxygen atoms. Common are complexes where sulfate is unidentate or chelating bidentate. Examples are respectively [Co(tren)(NH)(SO)] (tren = tris(2-aminoethyl)amine) and Co(phen)SO. All four oxygen atoms of sulfate bond to metals in some Dawson-type polyoxometalates, e.g. [SMoO]. | 0 | Theoretical and Fundamental Chemistry |
While MALDI is a common technique for large macro-molecules, it is often possible to also analyze small molecules with mass below 1000 Da. The problem with small molecules is that of matrix effects, where signal interference, detector saturation, or suppression of the analyte signal is possible since the matrices often consists of small molecules themselves. The choice of matrix is highly dependent on what molecules are to be analyzed. | 1 | Applied and Interdisciplinary Chemistry |
The discovery of plant viruses causing disease is often accredited to A. Mayer (1886) working in the Netherlands demonstrated that the sap of mosaic obtained from tobacco leaves developed mosaic symptom when injected in healthy plants. However the infection of the sap was destroyed when it was boiled. He thought that the causal agent was bacteria. However, after larger inoculation with a large number of bacteria, he failed to develop a mosaic symptom.
In 1898, Martinus Beijerinck, who was a Professor of Microbiology at the Technical University the Netherlands, put forth his concepts that viruses were small and determined that the "mosaic disease" remained infectious when passed through a Chamberland filter-candle. This was in contrast to bacteria microorganisms, which were retained by the filter. Beijerinck referred to the infectious filtrate as a "contagium vivum fluidum", thus the coinage of the modern term "virus".
After the initial discovery of the viral concept there was need to classify any other known viral diseases based on the mode of transmission even though microscopic observation proved fruitless. In 1939 Holmes published a classification list of 129 plant viruses. This was expanded and in 1999 there were 977 officially recognized, and some provisional, plant virus species.
The purification (crystallization) of TMV was first performed by Wendell Stanley, who published his findings in 1935, although he did not determine that the RNA was the infectious material. However, he received the Nobel Prize in Chemistry in 1946. In the 1950s a discovery by two labs simultaneously proved that the purified RNA of the TMV was infectious which reinforced the argument. The RNA carries genetic information to code for the production of new infectious particles.
More recently virus research has been focused on understanding the genetics and molecular biology of plant virus genomes, with a particular interest in determining how the virus can replicate, move and infect plants. Understanding the virus genetics and protein functions has been used to explore the potential for commercial use by biotechnology companies. In particular, viral-derived sequences have been used to provide an understanding of novel forms of resistance. The recent boom in technology allowing humans to manipulate plant viruses may provide new strategies for production of value-added proteins in plants. | 1 | Applied and Interdisciplinary Chemistry |
Thermodynamicists use this factor (Z) to alter the ideal gas equation to account for compressibility effects of real gases. This factor represents the ratio of actual to ideal specific volumes. It is sometimes referred to as a "fudge-factor" or correction to expand the useful range of the ideal gas law for design purposes. Usually this Z value is very close to unity. The compressibility factor image illustrates how Z varies over a range of very cold temperatures. | 0 | Theoretical and Fundamental Chemistry |
The pricing of pharmaceuticals is becoming a major challenge for health systems. A November 2020 study by the West Health Policy Center stated that more than 1.1 million senior citizens in the U.S. Medicare program are expected to die prematurely over the next decade because they will be unable to afford their prescription medications, requiring an additional $17.7 billion to be spent annually on avoidable medical costs due to health complications. | 1 | Applied and Interdisciplinary Chemistry |
The hemocompatability of a medical device is dependent upon surface charge, energy and topography. Devices that fail to be hemocompatabile run the risk of forming a thrombus, proliferation and compromising the immune system. Polymer coatings are applied to devices to increase their hemocompatability. Chemical cascades lead to the formation of fibrous clots. By choosing to use hydrophilic polymer coatings, protein adsorption decreases and the chance of negative interactions with the blood diminishes as well. One such polymer coating that increases hemocompatability is heparin. Heparin is a polymer coating that interacts with thrombin to prevent coagulation. Heparin has been shown to suppress platelet adhesion, complement activation and protein adsorption. | 0 | Theoretical and Fundamental Chemistry |
A formyl group, –CHO, can be introduced by treating the aryl diazonium salt with formaldoxime (), followed by hydrolysis of the aryl aldoxime to give the aryl aldehyde. This reaction is known as the Beech reaction. | 0 | Theoretical and Fundamental Chemistry |
As a consequence of the high shielding by the nearby ISS, the biological samples were predominantly exposed to galactic cosmic heavy ions, while electrons and a significant fraction of protons of the radiation belts and solar wind did not reach the samples. | 1 | Applied and Interdisciplinary Chemistry |
Brian G. Wowk is a Canadian medical physicist and cryobiologist known for the discovery and development of synthetic molecules that mimic the activity of natural antifreeze proteins in cryopreservation applications, sometimes called "ice blockers". As a senior scientist at 21st Century Medicine, Inc., he was a co-developer with Greg Fahy of key technologies enabling cryopreservation of large and complex tissues, including the first successful vitrification and transplantation of a mammalian organ (kidney). Wowk is also known for early theoretical work on future applications of molecular nanotechnology, especially cryonics, nanomedicine, and optics. In the early 1990s he wrote that nanotechnology would revolutionize optics, making possible virtual reality display systems optically indistinguishable from real scenery as in the fictitious Holodeck of Star Trek. These systems were described by Wowk in the chapter "Phased Array Optics" in the 1996 anthology Nanotechnology: Molecular Speculations on Global Abundance , and highlighted in the September 1998 Technology Watch section of Popular Mechanics magazine. | 1 | Applied and Interdisciplinary Chemistry |
The SRM Engine Suite is an engineering software tool used for simulating fuels, combustion and exhaust gas emissions in internal combustion engine (IC engine) applications. It is used worldwide by leading IC engine development organisations and fuel companies. The software is developed, maintained and supported by CMCL Innovations, Cambridge, U.K. | 1 | Applied and Interdisciplinary Chemistry |
Bacterial initiation factor 1 associates with the 30S ribosomal subunit in the A site and prevents an aminoacyl-tRNA from entering. It modulates IF2 binding to the ribosome by increasing its affinity. It may also prevent the 50S subunit from binding, stopping the formation of the 70S subunit. It also contains a β-domain fold common for nucleic acid-binding proteins. It is a homolog of eIF1A. Initiation factor IF-1 is the smallest translation factor at only 8.2kDa. Beyond blocking the A-site, it affects the dynamics of ribosome association and dissociation. IF-1 enhances dissociation with IF-3, likely by inducing conformational changes in the 30S subunit. It also increases the binding affinity of IF-2 to the 30S subunit, possibly by altering the subunit configuration. Though IF-1 occupies the A-site, it does so in a way that is distinct from tRNA binding. Structural studies show IF-1 inserts a loop into the minor groove of helix 44 of 16S rRNA, flipping out bases A1492 and A1493. This insertion repositions nucleotides of helix 44, transmitting a conformational change over a 70Å distance and rotating the head of the 30S subunit. IF-1 mutants can exhibit cold-sensitive phenotypes, indicating a role for the factor in cold shock adaptation. Certain mutations also lead to o of genes at low temperatures, suggesting IF-1 is involved in gene regulation. IF-1 actively modifies ribosome structure and dynamics during initiation, in addition to just blocking the A-site. | 1 | Applied and Interdisciplinary Chemistry |
The thickness of the ozone layer varies worldwide and is generally thinner near the equator and thicker near the poles. Thickness refers to how much ozone is in a column over a given area and varies from season to season. The reasons for these variations are due to atmospheric circulation patterns and solar intensity.
The majority of ozone is produced over the tropics and is transported towards the poles by stratospheric wind patterns. In the northern hemisphere these patterns, known as the Brewer–Dobson circulation, make the ozone layer thickest in the spring and thinnest in the fall. When ozone is produced by solar UV radiation in the tropics, it is done so by circulation lifting ozone-poor air out of the troposphere and into the stratosphere where the sun photolyzes oxygen molecules and turns them into ozone. Then, the ozone-rich air is carried to higher latitudes and drops into lower layers of the atmosphere.
Research has found that the ozone levels in the United States are highest in the spring months of April and May and lowest in October. While the total amount of ozone increases moving from the tropics to higher latitudes, the concentrations are greater in high northern latitudes than in high southern latitudes, with spring ozone columns in high northern latitudes occasionally exceeding 600 DU and averaging 450 DU whereas 400 DU constituted a usual maximum in the Antarctic before anthropogenic ozone depletion. This difference occurred naturally because of the weaker polar vortex and stronger Brewer–Dobson circulation in the northern hemisphere owing to that hemisphere’s large mountain ranges and greater contrasts between land and ocean temperatures. The difference between high northern and southern latitudes has increased since the 1970s due to the ozone hole phenomenon. The highest amounts of ozone are found over the Arctic during the spring months of March and April, but the Antarctic has the lowest amounts of ozone during the summer months of September and October, | 0 | Theoretical and Fundamental Chemistry |
In two dimensions, every figure which possesses an axis of symmetry is achiral, and it can be shown that every bounded achiral figure must have an axis of symmetry. (An axis of symmetry of a figure is a line , such that is invariant under the mapping , when is chosen to be the -axis of the coordinate system.) For that reason, a triangle is achiral if it is equilateral or isosceles, and is chiral if it is scalene.
Consider the following pattern:
This figure is chiral, as it is not identical to its mirror image:
But if one prolongs the pattern in both directions to infinity, one receives an (unbounded) achiral figure which has no axis of symmetry. Its symmetry group is a frieze group generated by a single glide reflection. | 0 | Theoretical and Fundamental Chemistry |
The spectral resolution can also be expressed in terms of physical quantities, such as velocity; then it describes the difference between velocities that can be distinguished through the Doppler effect. Then, the resolution is and the resolving power is
where is the speed of light. The STIS example above then has a spectral resolution of 51 km/s. | 0 | Theoretical and Fundamental Chemistry |
In general, the ideal buffer should have good conductivity, produce less heat and have a long life. There are a number of buffers used for agarose electrophoresis; common ones for nucleic acids include Tris/Acetate/EDTA (TAE) and Tris/Borate/EDTA (TBE). The buffers used contain EDTA to inactivate many nucleases which require divalent cation for their function. The borate in TBE buffer can be problematic as borate can polymerize, and/or interact with cis diols such as those found in RNA. TAE has the lowest buffering capacity, but it provides the best resolution for larger DNA. This means a lower voltage and more time, but a better product.
Many other buffers have been proposed, e.g. lithium borate (LB), iso electric histidine, pK matched goods buffers, etc.; in most cases the purported rationale is lower current (less heat) and or matched ion mobilities, which leads to longer buffer life. Tris-phosphate buffer has high buffering capacity but cannot be used if DNA extracted is to be used in phosphate sensitive reaction. LB is relatively new and is ineffective in resolving fragments larger than 5 kbp; However, with its low conductivity, a much higher voltage could be used (up to 35 V/cm), which means a shorter analysis time for routine electrophoresis. As low as one base pair size difference could be resolved in 3% agarose gel with an extremely low conductivity medium (1 mM lithium borate).
Other buffering system may be used in specific applications, for example, barbituric acid-sodium barbiturate or Tris-barbiturate buffers may be used for in agarose gel electrophoresis of proteins, for example in the detection of abnormal distribution of proteins. | 1 | Applied and Interdisciplinary Chemistry |
* Sadideen H, Swaminathan R. (2006): "Macroprolactin: what is it and what is its importance?" Int J Clin Pract. 60(4):457-61. | 1 | Applied and Interdisciplinary Chemistry |
Together with the formula above, the boiling-point elevation can in principle be used to measure the degree of dissociation or the molar mass of the solute. This kind of measurement is called ebullioscopy (Latin-Greek "boiling-viewing"). However, since superheating is difficult to avoid, precise ΔT measurements are difficult to carry out, which was partly overcome by the invention of the Beckmann thermometer. Furthermore, the cryoscopic constant that determines freezing-point depression is larger than the ebullioscopic constant, and since the freezing point is often easier to measure with precision, it is more common to use cryoscopy. | 0 | Theoretical and Fundamental Chemistry |
Modern steel making in India began with the setting of first blast furnace of India at Kulti in 1870 and production began in 1874, which was set up by Bengal Iron Works. The Ordnance Factory Board established Metal & Steel Factory (MSF) at Calcutta, in 1872 The Tata Iron and Steel Company (TISCO) was established by Dorabji Tata in 1907, as part of his father's conglomerate. By 1939 Tata operated the largest steel plant in the British Empire, and accounted for a significant proportion of the 2 million tons pig iron and 1.13 of steel produced in British India annually. | 1 | Applied and Interdisciplinary Chemistry |
Schymanski graduated with a B.Sc. in Chemistry and a B.E. in Environmental Engineering from the University of Western Australia in 2003. While at the University of Western Australia, Schymanski combined chemistry and environmental engineering to study contaminated sites that required assessment and remediation. As an undergraduate, she participated in the 2002 Nobel Laureate conference which brings Nobel laureates and young scientists together; Schymanski and Pia Sappl were the first students from the University of Western Australia to receive this invitation and possibly the first Australians.
After college, Schymanski spent three years at Golder Associates in Perth as an environmental engineer and then joined the Helmholtz Centre for Environmental Research in Leipzig Germany where she finished her Ph.D. in 2011. Schymanski's subsequent postdoctoral position was at the Swiss Federal Institute of Aquatic Science and Technology (Eawag) including a Marie Curie Intra-European Postdoctoral Fellowship. Schymanski is currently an Associate Professor at the University of Luxembourg where she is the head of the Environmental Cheminformatics Group.
In 2021, Schymanski was interviewed by the Metabolomics Society article in MetaboNews and during the interview she describes her introduction to the field of metabolomics, the current strengths of the field, and potential future applications of metabolomics research. | 0 | Theoretical and Fundamental Chemistry |
When Amagats law is valid and' the gas mixture is made of ideal gases,
where:
: is the pressure of the gas mixture,
: is the volume of the i-th component of the gas mixture,
: is the total volume of the gas mixture,
: is the amount of substance of i-th component of the gas mixture (in mol),
: is the total amount of substance of gas mixture (in mol),
: is the ideal, or universal, gas constant, equal to the product of the Boltzmann constant and the Avogadro constant,
: is the absolute temperature of the gas mixture (in K),
: is the mole fraction of the i-th component of the gas mixture.
It follows that the mole fraction and volume fraction are the same. This is true also for other equation of state. | 0 | Theoretical and Fundamental Chemistry |
Depending on the job specification, there are multiple forms of body constructions available:
* Tie rod cylinders: The most common cylinder constructions that can be used in many types of loads. Has been proven to be the safest form.
* Flanged-type cylinders: Fixed flanges are added to the ends of cylinder, however, this form of construction is more common in hydraulic cylinder construction.
* One-piece welded cylinders: Ends are welded or crimped to the tube, this form is inexpensive but makes the cylinder non-serviceable.
* Threaded end cylinders: Ends are screwed onto the tube body. The reduction of material can weaken the tube and may introduce thread concentricity problems to the system. | 1 | Applied and Interdisciplinary Chemistry |
Mars Guy Fontana was a corrosion engineer, professor of Metallurgical Engineering at Ohio State University. He was born April 6, 1910, in Iron Mountain, Michigan, and died February 29, 1988. | 1 | Applied and Interdisciplinary Chemistry |
Cryo-adsorption is a method used for hydrogen storage where gaseous hydrogen at cryogenic temperatures (150—60 K) is physically adsorbed on porous material, mostly activated carbon. The achievable storage density is between liquid-hydrogen (LH) storage systems and compressed-hydrogen (CGH) storage systems. | 0 | Theoretical and Fundamental Chemistry |
For effective range see Buffer capacity, above. Also see Good's buffers for the historic design principles and favourable properties of these buffer substances in biochemical applications. | 0 | Theoretical and Fundamental Chemistry |
Under standard atmospheric conditions (25 °C and pressure of 1 bar), the dynamic viscosity of air is 18.5 μPa·s, roughly 50 times smaller than the viscosity of water at the same temperature. Except at very high pressure, the viscosity of air depends mostly on the temperature. Among the many possible approximate formulas for the temperature dependence (see Temperature dependence of viscosity), one is:
which is accurate in the range −20 °C to 400 °C. For this formula to be valid, the temperature must be given in kelvins; then corresponds to the viscosity in Pa·s. | 1 | Applied and Interdisciplinary Chemistry |
McQuillan was awarded the Rosenhain Medal in 1965. She was on the Interservices Metallurgical Research Council until 1989 and in 1967 served as vice-president of the Institute of Metals. In 1968 she was fundamental to the First International Conference on Titanium in London. | 1 | Applied and Interdisciplinary Chemistry |
Paul J. Gemperline (born 1955) is an American analytical chemist and chemometrician. He is a Distinguished Professor of Chemistry at East Carolina University (ECU) located in Greenville, North Carolina and has been the recipient of several scientific awards, including the 2003 Eastern Analytical Symposium Award in Chemometrics. He is author of more than 60 publications in the field of chemometrics. Dr. Gemperline served as Dean of the Graduate School at ECU from 2008 to 2022. He retired from ECU June 30, 2022 and is now professor emeritus. | 0 | Theoretical and Fundamental Chemistry |
If the enthalpy and entropy are roughly constant as temperature varies over a certain range, then the Van 't Hoff plot is approximately linear when plotted over that range. However, in some cases the enthalpy and entropy do change dramatically with temperature. A first-order approximation is to assume that the two different reaction products have different heat capacities. Incorporating this assumption yields an additional term in the expression for the equilibrium constant as a function of temperature. A polynomial fit can then be used to analyze data that exhibits a non-constant standard enthalpy of reaction:
where
Thus, the enthalpy and entropy of a reaction can still be determined at specific temperatures even when a temperature dependence exists. | 0 | Theoretical and Fundamental Chemistry |
The chemistry of the Mg ion, as applied to enzymes, uses the full range of this ions unusual reaction chemistry to fulfill a range of functions. Mg interacts with substrates, enzymes, and occasionally both (Mg may form part of the active site). In general, Mg interacts with substrates through inner sphere coordination, stabilising anions or reactive intermediates, also including binding to ATP and activating the molecule to nucleophilic attack. When interacting with enzymes and other proteins, Mg may bind using inner or outer sphere coordination, to either alter the conformation of the enzyme or take part in the chemistry of the catalytic reaction. In either case, because Mg is only rarely fully dehydrated during ligand binding, it may be a water molecule associated with the Mg that is important rather than the ion itself. The Lewis acidity of Mg (pK' 11.4) is used to allow both hydrolysis and condensation reactions (most common ones being phosphate ester hydrolysis and phosphoryl transfer) that would otherwise require pH values greatly removed from physiological values. | 1 | Applied and Interdisciplinary Chemistry |
The first swords known so far date to ca. the 33rd to 31st centuries BCE, during the Early Bronze Age, and have been founds at Arslantepe by Marcella Frangipane of Sapienza University of Rome. A cache of nine swords and daggers was found; they are cast from an arsenic–copper alloy. Analysis of two swords showed a copper/arsenic composition of 96%/3.15% and 93%/2.65%. Two daggers tested at copper/arsenic 96%/3.99% and 97%/3.06% with a third at copper/silver composition of 50%/35% with a trace of arsenic. Among them, three swords were beautifully inlaid with silver. These objects were found in the "hall of weapons" in the area of the palace.
These weapons have a total length of 45 to 60 cm which suggests their description as either short swords or long daggers.
These discoveries were made back in the 1980s. They belong to the local phase VI A. Also, 12 spearheads were found. These objects were dated to the period VI A (3400-3200 BC). Phase VI A at Arslantepe ended in destruction—the city was burned.
Kfar Monash Hoard was found in 1962 in Israel. Among the many copper objects in it, "Egyptian type" copper axes were found. These axes were made using copper-arsenic-nickel (CuAsNi) alloy that probably originated in Arslantepe area. Objects from Arslantepe using such polymetallic ores are mainly ascribed to Level VIA (3400–3000 BCE), dating to the Uruk period.
The next Phases or periods were VI B1 and VI B2. This is the time to which the other big discovery at Arslantepe belongs. This is the rich “Royal Tomb” where high quality pottery, and a large number of refined metal objects, made with several kinds of copper based alloys, were found. A sword was also found in the tomb. This tomb is also known as the tomb of "Signor Arslantepe", as he was called by archaeologists. He was about 40 years old, and the tomb is radiocarbon dated to 3085–2900 Cal. BC.
This “Royal Tomb” dates to the beginning of period VI B2, or perhaps even earlier to period VI B1. There’s a considerable similarity between these two groups of objects in the “hall of weapons”, and in the “Royal Tomb”, and the times of manufacture of some of them must have been pretty close together. | 1 | Applied and Interdisciplinary Chemistry |
In aquatic toxicology multiple databases exist and each generally pertains to a single aspect of aquatic toxicology such as PCBs, tissue residues or sediment toxicity. Other informational and regulatory databases on toxicology in general are maintained by the U.S. EPA, USGS, United States Army Corps of Engineers and the National Oceanic and Atmospheric Administration. In the U.S. there are three major databases pertaining specifically to aquatic toxicology: the Toxicity/Residue Database, the Environmental Residue Effects Database and the ECOTOX database. | 1 | Applied and Interdisciplinary Chemistry |
The method of transport of endocannabinoids through the cell membrane and cytoplasm to their respective degradation enzymes has been rigorously debated for nearly two decades, and a putative endocannabinoid membrane transporter was proposed. However, as lipophilic molecules endocannabinoids readily pass through the cell lipid bilayer without assistance and would more likely need a chaperone through the cytoplasm to the endoplasmic reticulum where the enzyme FAAH is located. More recently fatty acid-binding proteins (FABPs) and heat shock proteins (Hsp70s) have been described and verified as such chaperones, and their inhibitors have been synthesized. The inhibition of endocannabinoid reuptake raises the amount of those neurotransmitters available in the synaptic cleft and therefore increases neurotransmission. Following the increase of neurotransmission in the endocannabinoid system is the stimulation of its functions which, in humans, include: suppression of pain perception (analgesia), increased appetite, mood elevation and inhibition of short-term memory. | 1 | Applied and Interdisciplinary Chemistry |
# Fung, Y.C. (1960). "Fluctuating Lift and Drag Acting on a Cylinder in a Flow at Supercritical Reynolds Numbers," J. Aerospace Sci., 27 (11), pp. 801–814.
# Roshko, A. (1961). "Experiments on the flow past a circular cylinder at very high Reynolds number," J. Fluid Mech., 10, pp. 345–356.
# Jones, G.W. (1968). "Aerodynamic Forces on Stationary and Oscillating Circular Cylinder at High Reynolds Numbers," ASME Symposium on Unsteady Flow, Fluids Engineering Div. , pp. 1–30.
# Jones, G.W., Cincotta, J.J., Walker, R.W. (1969). "Aerodynamic Forces on Stationary and Oscillating Circular Cylinder at High Reynolds Numbers," NASA Report TAR-300, pp. 1–66.
# Achenbach, E. Heinecke, E. (1981). "On vortex shedding from smooth and rough cylinders in the range of Reynolds numbers 6x103 to 5x106," J. Fluid Mech. 109, pp. 239–251.
# Schewe, G. (1983). "On the force fluctuations acting on a circular cylinder in crossflow from subcritical up to transcritical Raynolds numbers," J. Fluid Mech., 133, pp. 265–285.
# Kawamura, T., Nakao, T., Takahashi, M., Hayashi, T., Murayama, K., Gotoh, N., (2003). "Synchronized Vibrations of a Circular Cylinder in Cross Flow at Supercritical Reynolds Numbers", ASME J. Press. Vessel Tech., 125, pp. 97–108, DOI:10.1115/1.1526855.
# Zdravkovich, M.M. (1997). Flow Around Circular Cylinders, Vol.I, Oxford Univ. Press. Reprint 2007, p. 188.
# Zdravkovich, M.M. (2003). Flow Around Circular Cylinders, Vol. II, Oxford Univ. Press. Reprint 2009, p. 761.
# Bartran, D. (2015). "Support Flexibility and Natural Frequencies of Pipe Mounted Thermowells," ASME J. Press. Vess. Tech., 137, pp. 1–6, DOI:10.1115/1.4028863
# Botterill, N. ( 2010). "Fluid structure interaction modelling of cables used in civil engineering structures," PhD dissertation (http://etheses.nottingham.ac.uk/11657/), University of Nottingham.
# Bartran, D. (2018). "The Drag Crisis and Thermowell Design", J. Press. Ves. Tech. 140(4), 044501, Paper No: PVT-18-1002. DOI: 10.1115/1.4039882. | 1 | Applied and Interdisciplinary Chemistry |
PIPES has two pKa values. One pKa (6.76 at 25 °C) is near the physiological pH which makes it useful in cell culture work. Its effective buffering range is 6.1-7.5 at 25 °C. The second pKa value is at 2.67 with a buffer range of from 1.5-3.5. PIPES has been documented minimizing lipid loss when buffering glutaraldehyde histology in plant and animal tissues. Fungal zoospore fixation for fluorescence microscopy and electron microscopy were optimized with a combination of glutaraldehyde and formaldehyde in PIPES buffer. It has a negligible capacity to bind divalent ions. | 1 | Applied and Interdisciplinary Chemistry |
Australian rangelands cover approximately 75% of the nations land mass. Characteristically arid and semi arid the rangelands offer wide variations in climate, land and soil. The pastoral industry and particularly pastoral practices equate to 60% of rangeland usage. Subsequently, Australias 25.5 million beef cattle generate a gross average of $7.4 million per year. The Northern Rangelands are the centre for beef productivity in Australia, producing 70% of national beef in the year 2005 - 2006. The grazing of cattle is the primary use of Australias Northern Rangelands, and as such, it has enabled them to become a central organ for Australian agricultural enterprises. The production of beef in these rangelands draws upon a traditional low input-low output system of land management. Australias Northern rangelands have engaged in recent innovations to increase beef productivity whilst reducing greenhouse gas emissions. These strategies include; improving herd genetics, utilising feed bases, and promoting both feedlot finishing and property infrastructure. Species of cows such as the Red Angus, Tuli, Belmont Reds, Senapol and Brahman bulls are common species utilised in the Northern Rangeland industry for sustained productivity and carcass yields given Australia's arid and semi arid climate.
NAPCO has adopted these strategies and complemented them by utilising solar energy systems, perennial pastures and minimum tillage to increase productivity and limit carbon emissions. Further, the company has significantly contributed to developing a genetic improvement program which has introduced a tropically adapted cattle breed which has improved fertility and growth. NAPCO's composite cattle breeds, the Alexandria and Kynuna composites, are suited to arid and semi arid climates which are the product of the environmental conditions in the northern rangelands. The composite cattle proves to be more durable compared to the Shorthorn cow variations, due to their increased drought and disease resistance and heat tolerance. The composites are a more profitable long term species for NAPCO that has ensured beef productivity has been maintained whilst minimising environmental degradation. | 1 | Applied and Interdisciplinary Chemistry |
Cytochemical research aims to study individual cells that may contain several cell types within a tissue. It takes a nondestructive approach to study the localization of the cell. By remaining the cell components intact, researcher are able to study the intact cell activity rather than studying an isolated biochemical activity which the result may be influenced by the distorted cell membrane and spatial difference. | 1 | Applied and Interdisciplinary Chemistry |
Professor David Todd at Pomona College was testing the dehydration of 2-methylcyclohexanol or 4-methylcyclohexanol and unexpectedly interrupted the alkene distillation midway to have lunch with his secretary, Evelyn Jacoby. After lunch, he continued his distillation but kept the early products separate from the completed ones. The analysis showed two different alkene ratios. The reaction products and pathways to the products seem to have changed over time. Dr. Todd called this phenomenon the “Evelyn effect.” | 0 | Theoretical and Fundamental Chemistry |
Ghiorso invented numerous techniques and machines for isolating and identifying heavy elements atom-by-atom. He is generally credited with implementing the multichannel analyzer and the technique of recoil to isolate reaction products, although both of these were significant extensions of previously understood concepts. His concept for a new type of accelerator, the Omnitron, is acknowledged to have been a brilliant advance that probably would have enabled the Berkeley lab to discover numerous additional new elements, but the machine was never built, a victim of the evolving political landscape of the 1970s in the U.S. that de-emphasized basic nuclear research and greatly expanded research on environmental, health, and safety issues. Partially as a result of the failure to build the Omnitron, Ghiorso (together with colleagues Bob Main and others) conceived the joining of the HILAC and the Bevatron, which he called the Bevalac. This combination machine, an ungainly articulation across the steep slope at the Rad Lab, provided heavy ions at GeV energies, thereby enabling development of two new fields of research: "high-energy nuclear physics," meaning that the compound nucleus is sufficiently hot to exhibit collective dynamical effects, and heavy ion therapy, in which high-energy ions are used to irradiate tumors in cancer patients. Both of these fields have expanded into activities in many laboratories and clinics worldwide. | 1 | Applied and Interdisciplinary Chemistry |
The lower-limit size of a coffee ring depends on the time scale competition between the liquid evaporation and the movement of suspended particles. When the liquid evaporates much faster than the particle movement near a three-phase contact line, coffee ring cannot be formed successfully. Instead, these particles will disperse uniformly on a surface upon complete liquid evaporation. For suspended particles of size 100 nm, the minimum diameter of the coffee ring structure is found to be 10 μm, or about 10 times smaller than the width of human hair. The shape of particles in the liquid is responsible for coffee ring effect. On porous substrates, the competition among infiltration, particle motion and evaporation of the solvent governs the final deposition morphology.
The pH of the solution of the drop influences the final deposit pattern. The transition between these patterns is explained by considering how DLVO interactions such as the electrostatic and Van der Waals forces modify the particle deposition process. | 0 | Theoretical and Fundamental Chemistry |
Endogenous retroviruses (ERVs) are endogenous viral elements in the genome that closely resemble and can be derived from retroviruses. They are abundant in the genomes of jawed vertebrates, and they comprise up to 5–8% of the human genome (lower estimates of ~1%).
ERVs are a vertically inherited proviral sequence and a subclass of a type of gene called a transposon, which can normally be packaged and moved within the genome to serve a vital role in gene expression and in regulation. ERVs however lack most transposon functions, are typically not infectious and are often defective genomic remnants of the retroviral replication cycle. They are distinguished as germline provirus retroelements due to their integration and reverse-transcription into the nuclear genome of the host cell.
Researchers have suggested that retroviruses evolved from a type of transposon called a retrotransposon, a Class I element; these genes can mutate and instead of moving to another location in the genome they can become exogenous or pathogenic. This means that not all ERVs may have originated as an insertion by a retrovirus but that some may have been the source for the genetic information in the retroviruses they resemble. When integration of viral DNA occurs in the germ-line, it can give rise to an ERV, which can later become fixed in the gene pool of the host population. | 1 | Applied and Interdisciplinary Chemistry |
One theme of research in evolutionary developmental biology ("evo-devo") is investigating the role of enhancers and other cis-regulatory elements in producing morphological changes via developmental differences between species. | 1 | Applied and Interdisciplinary Chemistry |
The 2-norbornyl cation can be made by a multitude of synthetic routes. These routes can be grouped into three different classes: σ Formation, π Formation, and Formation by Rearrangement. Each of these is discussed separately below. | 0 | Theoretical and Fundamental Chemistry |
GaN is a very hard (Knoop hardness 14.21 GPa), mechanically stable wide-bandgap semiconductor material with high heat capacity and thermal conductivity. In its pure form it resists cracking and can be deposited in thin film on sapphire or silicon carbide, despite the mismatch in their lattice constants. GaN can be doped with silicon (Si) or with oxygen to n-type and with magnesium (Mg) to p-type. However, the Si and Mg atoms change the way the GaN crystals grow, introducing tensile stresses and making them brittle. Gallium nitride compounds also tend to have a high dislocation density, on the order of 10 to 10 defects per square centimeter.
The U.S. Army Research Laboratory (ARL) provided the first measurement of the high field electron velocity in GaN in 1999. Scientists at ARL experimentally obtained a peak steady-state velocity of , with a transit time of 2.5 picoseconds, attained at an electric field of 225 kV/cm. With this information, the electron mobility was calculated, thus providing data for the design of GaN devices. | 0 | Theoretical and Fundamental Chemistry |
(+)-Discodermolide has also been found to be neuroprotective in recent Alzheimer research. The microtubule-stabilizing feature of (+)-discodermolide was used to restore neuron functions that have been disrupted by the amyloid induced sequestration. Tau protein is known to stabilize the microtubule network in healthy neurons. It served as the “railroad track” upon which actin, tubulin, mitochondria, neurotransmitter-related enzymes and vesicles carrying messenger proteins are delivered. The presence of Amyloid in the cell could lead to tau protein aggregation and microtubule numbers reduction. In transgenic mouse model for human tauopathy, (+)-discodermolide stabilizes microtubules and restores fast axonal transport in cells, offsetting the loss of function caused by aggregation of tau protein. The motor-impaired mice exhibited a full restoration of normal movement with (+)-discodermolide treatment. | 0 | Theoretical and Fundamental Chemistry |
A key component of a hydrological transport model is the surface runoff element, which allows assessment of sediment, fertilizer, pesticide and other chemical contaminants. Building on the work of Horton, the unit hydrograph theory was developed by Dooge in 1959. It required the presence of the National Environmental Policy Act and kindred other national legislation to provide the impetus to integrate water chemistry to hydrology model protocols. In the early 1970s the U.S. Environmental Protection Agency (EPA) began sponsoring a series of water quality models in response to the Clean Water Act. An example of these efforts was developed at the Southeast Water Laboratory, one of the first attempts to calibrate a surface runoff model with field data for a variety of chemical contaminants.
The attention given to surface runoff contaminant models has not matched the emphasis on pure hydrology models, in spite of their role in the generation of stream loading contaminant data. In the United States the EPA has had difficulty interpreting diverse proprietary contaminant models and has to develop its own models more often than conventional resource agencies, who, focused on flood forecasting, have had more of a centroid of common basin models. | 1 | Applied and Interdisciplinary Chemistry |
The reaction mechanism of decomposition of diazocarbonyl compounds with copper begins with the formation of a copper carbene complex. Evidence for the formation of copper carbenes is provided by comparison to the behavior of photolytically generated free carbenes and the observation of appreciable enantioselectivity in cyclopropanations with chiral copper complexes. Upon formation of the copper carbene, either insertion or addition takes place to afford carbocycles or cyclopropanes, respectively. Both addition and insertion proceed with retention of configuration. Thus, diastereoselectivity may often be dictated by the configuration of the starting material. | 0 | Theoretical and Fundamental Chemistry |
Charles Roger Slack (22 April 1937 – 24 October 2016) was a British-born plant biologist and biochemist who lived and worked in Australia (1962–1970) and New Zealand (1970–2000). In 1966, jointly with Marshall Hatch, he discovered C4 photosynthesis (also known as the Hatch Slack Pathway). | 1 | Applied and Interdisciplinary Chemistry |
Saltmod accepts four different reservoirs, three of which are in the soil profile:
# a surface reservoir
# an upper (shallow) soil reservoir or root zone
# an intermediate soil reservoir or transition zone
# a deep reservoir or aquifer.
The upper soil reservoir is defined by the soil depth from which water can evaporate or be taken up by plant roots. It can be equal to the rootzone.<br>
The root zone can be saturated, unsaturated, or partly saturated, depending on the water balance. All water movements in this zone are vertical, either upward or downward, depending on the water balance. (In a future version of Saltmod, the upper soil reservoir may be divided into two equal parts to detect the trend in the vertical salinity distribution.)<br>
The transition zone can also be saturated, unsaturated or partly saturated. All flows in this zone are vertical, except the flow to subsurface drains.<br>
If a horizontal subsurface drainage system is present, this must be placed in the transition zone, which is then divided into two parts: an upper transition zone (above drain level) and a lower transition zone (below drain level).<br>
If one wishes to distinguish an upper and lower part of the transition zone in the absence of a subsurface drainage system, one may specify in the input data a drainage system with zero intensity.<br>
The aquifer has mainly horizontal flow. Pumped wells, if present, receive their water from the aquifer only. | 0 | Theoretical and Fundamental Chemistry |
Archaeometallurgical scientific knowledge and technological development originated in numerous centers of Africa; the centers of origin were located in West Africa, Central Africa, and East Africa; consequently, as these origin centers are located within inner Africa, these archaeometallurgical developments are thus native African technologies. Iron metallurgical development occurred 2631 BCE – 2458 BCE at Lejja, in Nigeria, 2136 BCE – 1921 BCE at Obui, in Central Africa Republic, 1895 BCE – 1370 BCE at Tchire Ouma 147, in Niger, and 1297 BCE – 1051 BCE at Dekpassanware, in Togo.
Though there is some uncertainty, some archaeologists believe that iron metallurgy was developed independently in sub-Saharan Africa (possibly in West Africa).
Inhabitants of Termit, in eastern Niger, smelted iron around 1500 BC.
In the region of the Aïr Mountains in Niger there are also signs of independent copper smelting between 2500 and 1500 BC. The process was not in a developed state, indicating smelting was not foreign. It became mature about 1500 BC.
Archaeological sites containing iron smelting furnaces and slag have also been excavated at sites in the Nsukka region of southeast Nigeria in what is now Igboland: dating to 2000 BC at the site of Lejja (Eze-Uzomaka 2009) and to 750 BC and at the site of Opi (Holl 2009). The site of Gbabiri (in the Central African Republic) has yielded evidence of iron metallurgy, from a reduction furnace and blacksmith workshop; with earliest dates of 896–773 BC and 907–796 BC respectively. Similarly, smelting in bloomery-type furnaces appear in the Nok culture of central Nigeria by about 550 BC and possibly a few centuries earlier.
There is also evidence that carbon steel was made in Western Tanzania by the ancestors of the Haya people as early as 2,300 to 2,000 years ago (about 300 BC or soon after) by a complex process of "pre-heating" allowing temperatures inside a furnace to reach 1300 to 1400 °C.
Iron and copper working spread southward through the continent, reaching the Cape around AD 200. The widespread use of iron revolutionized the Bantu-speaking farming communities who adopted it, driving out and absorbing the rock tool using hunter-gatherer societies they encountered as they expanded to farm wider areas of savanna. The technologically superior Bantu-speakers spread across southern Africa and became wealthy and powerful, producing iron for tools and weapons in large, industrial quantities.
The earliest records of bloomery-type furnaces in East Africa are discoveries of smelted iron and carbon in Nubia that date back between the 7th and 6th centuries BC, particularly in Meroe where there are known to have been ancient bloomeries that produced metal tools for the Nubians and Kushites and produced surplus for their economy. | 1 | Applied and Interdisciplinary Chemistry |
Solenoidal has its origin in the Greek word for solenoid, which is σωληνοειδές (sōlēnoeidēs) meaning pipe-shaped, from σωλην (sōlēn) or pipe. | 1 | Applied and Interdisciplinary Chemistry |
Thixotropy is a time-dependent shear thinning property. Certain gels or fluids that are thick or viscous under static conditions will flow (become thinner, less viscous) over time when shaken, agitated, shear-stressed, or otherwise stressed (time-dependent viscosity). They then take a fixed time to return to a more viscous state.
Some non-Newtonian pseudoplastic fluids show a time-dependent change in viscosity; the longer the fluid undergoes shear stress, the lower its viscosity. A thixotropic fluid is a fluid which takes a finite time to attain equilibrium viscosity when introduced to a steep change in shear rate. Some thixotropic fluids return to a gel state almost instantly, such as ketchup, and are called pseudoplastic fluids. Others such as yogurt take much longer and can become nearly solid. Many gels and colloids are thixotropic materials, exhibiting a stable form at rest but becoming fluid when agitated. Thixotropy arises because particles or structured solutes require time to organize.
Some fluids are anti-thixotropic: constant shear stress for a time causes an increase in viscosity or even solidification. Fluids which exhibit this property are sometimes called rheopectic. Anti-thixotropic fluids are less well documented than thixotropic fluids. | 1 | Applied and Interdisciplinary Chemistry |
In three dimensions, there are an infinite number of point groups, but all of them can be classified by several families.
* C (for cyclic) has an n-fold rotation axis.
** C is C with the addition of a mirror (reflection) plane perpendicular to the axis of rotation (horizontal plane).
** C is C with the addition of n mirror planes containing the axis of rotation (vertical planes).
* C denotes a group with only mirror plane (for Spiegel, German for mirror) and no other symmetry elements.
* S (for Spiegel, German for mirror) contains only a n-fold rotation-reflection axis. The index, n, should be even because when it is odd an n-fold rotation-reflection axis is equivalent to a combination of an n-fold rotation axis and a perpendicular plane, hence S = C for odd n.
* C has only a rotoinversion axis. This notation is rarely used because any rotoinversion axis can be expressed instead as rotation-reflection axis: For odd n, C = S and C = S = C, and for even n, C = S. Only the notation C (meaning C) is commonly used, and some sources write C, C etc.
* D (for dihedral, or two-sided) has an n-fold rotation axis plus n twofold axes perpendicular to that axis.
** D has, in addition, a horizontal mirror plane and, as a consequence, also n vertical mirror planes each containing the n-fold axis and one of the twofold axes.
** D has, in addition to the elements of D, n vertical mirror planes which pass between twofold axes (diagonal planes).
* T (the chiral tetrahedral group) has the rotation axes of a tetrahedron (three 2-fold axes and four 3-fold axes).
** T includes diagonal mirror planes (each diagonal plane contains only one twofold axis and passes between two other twofold axes, as in D). This addition of diagonal planes results in three improper rotation operations S.
** T includes three horizontal mirror planes. Each plane contains two twofold axes and is perpendicular to the third twofold axis, which results in inversion center i.
* O (the chiral octahedral group) has the rotation axes of an octahedron or cube (three 4-fold axes, four 3-fold axes, and six diagonal 2-fold axes).
** O includes horizontal mirror planes and, as a consequence, vertical mirror planes. It contains also inversion center and improper rotation operations.
* I (the chiral icosahedral group) indicates that the group has the rotation axes of an icosahedron or dodecahedron (six 5-fold axes, ten 3-fold axes, and 15 2-fold axes).
** I includes horizontal mirror planes and contains also inversion center and improper rotation operations.
All groups that do not contain more than one higher-order axis (order 3 or more) can be arranged as shown in a table below; symbols in red are rarely used.
In crystallography, due to the crystallographic restriction theorem, n is restricted to the values of 1, 2, 3, 4, or 6. The noncrystallographic groups are shown with grayed backgrounds. D and D are also forbidden because they contain improper rotations with n = 8 and 12 respectively. The 27 point groups in the table plus T, T, T, O and O constitute 32 crystallographic point groups.
Groups with n = ∞ are called limit groups or Curie groups. There are two more limit groups, not listed in the table: K (for Kugel, German for ball, sphere), the group of all rotations in 3-dimensional space; and K, the group of all rotations and reflections. In mathematics and theoretical physics they are known respectively as the special orthogonal group and the orthogonal group in three-dimensional space, with the symbols SO(3) and O(3). | 0 | Theoretical and Fundamental Chemistry |
In continuum mechanics, including fluid dynamics, an upper-convected time derivative or Oldroyd derivative, named after James G. Oldroyd, is the rate of change of some tensor property of a small parcel of fluid that is written in the coordinate system rotating and stretching with the fluid.
The operator is specified by the following formula:
where:
* is the upper-convected time derivative of a tensor field
* is the substantive derivative
* is the tensor of velocity derivatives for the fluid.
The formula can be rewritten as:
By definition, the upper-convected time derivative of the Finger tensor is always zero.
It can be shown that the upper-convected time derivative of a spacelike vector field is just its Lie derivative by the velocity field of the continuum.
The upper-convected derivative is widely used in polymer rheology for the description of the behavior of a viscoelastic fluid under large deformations. | 1 | Applied and Interdisciplinary Chemistry |
The Kirkendall effect is the motion of the interface between two metals that occurs as a consequence of the difference in diffusion rates of the metal atoms. The effect can be observed for example by placing insoluble markers at the interface between a pure metal and an alloy containing that metal, and heating to a temperature where atomic diffusion is reasonable for the given timescale; the boundary will move relative to the markers.
This process was named after Ernest Kirkendall (1914–2005), assistant professor of chemical engineering at Wayne State University from 1941 to 1946. The paper describing the discovery of the effect was published in 1947.
The Kirkendall effect has important practical consequences. One of these is the prevention or suppression of voids formed at the boundary interface in various kinds of alloy to metal bonding. These are referred to as Kirkendall voids. | 1 | Applied and Interdisciplinary Chemistry |
Recombinant DNA vectors function as carriers of the foreign DNA. Plasmids are small, closed-circular DNA molecules that exist from the chromosomes of their host. Their replication is to be under stringent control (low copy number) or relaxed (high copy number). The restriction sites, called the multiple cloning site or polylinker, give a wide choice of restriction site for use in the cloning step. | 1 | Applied and Interdisciplinary Chemistry |
Wastewater pollutants discharged by iron and steel mills includes gasification products such as benzene, naphthalene, anthracene, cyanide, ammonia, phenols and cresols, together with a range of more complex organic compounds known collectively as polycyclic aromatic hydrocarbons (PAH). Treatment technologies include recycling of wastewater; settling basins, clarifiers and filtration systems for solids removal; oil skimmers and filtration; chemical precipitation and filtration for dissolved metals; carbon adsorption and biological oxidation for organic pollutants; and evaporation.
Pollutants generated by other types of smelters varies with the base metal ore. For example, aluminum smelters typically generate fluoride, benzo(a)pyrene, antimony and nickel, as well as aluminum. Copper smelters typically discharge cadmium, lead, zinc, arsenic and nickel, in addition to copper. Lead smelters may discharge antimony, asbestos, cadmium, copper and zinc, in addition to lead. | 1 | Applied and Interdisciplinary Chemistry |
In genetics, shotgun sequencing is a method used for sequencing random DNA strands. It is named by analogy with the rapidly expanding, quasi-random shot grouping of a shotgun.
The chain-termination method of DNA sequencing ("Sanger sequencing") can only be used for short DNA strands of 100 to 1000 base pairs. Due to this size limit, longer sequences are subdivided into smaller fragments that can be sequenced separately, and these sequences are assembled to give the overall sequence.
In shotgun sequencing, DNA is broken up randomly into numerous small segments, which are sequenced using the chain termination method to obtain reads. Multiple overlapping reads for the target DNA are obtained by performing several rounds of this fragmentation and sequencing. Computer programs then use the overlapping ends of different reads to assemble them into a continuous sequence.
Shotgun sequencing was one of the precursor technologies that was responsible for enabling whole genome sequencing. | 1 | Applied and Interdisciplinary Chemistry |
Pores that are not of the same size will fill at different values of pressure, with the smaller ones filling first. This difference in filling rate can be a beneficial application of capillary condensation. Many materials have different pore sizes with ceramics being one of the most commonly encountered. In materials with different pore sizes, curves can be constructed similar to Figure 7. A detailed analysis of the shape of these isotherms is done using the Kelvin equation. This enables the pore size distribution to be determined. While this is a relatively simple method of analyzing the isotherms, a more in depth analysis of the isotherms is done using the BET method. Another method of determining the pore size distribution is by using a procedure known as Mercury Injection Porosimetry. This uses the volume of mercury taken up by the solid as the pressure increases to create the same isotherms mentioned above. An application where pore size is beneficial is in regards to oil recovery. When recovering oil from tiny pores, it is useful to inject gas and water into the pore. The gas will then occupy the space where the oil once was, mobilizing the oil, and then the water will displace some of the oil forcing it to leave the pore. | 1 | Applied and Interdisciplinary Chemistry |
The S−H bond in thiols is weak compared to the O−H bond in alcohols. For CHX−H, the bond enthalpies are for X = S and for X = O. Hydrogen-atom abstraction from a thiol gives a thiyl radical with the formula RS, where R = alkyl or aryl. | 0 | Theoretical and Fundamental Chemistry |
For electrolyte solution in a channel with a macro- or micro-scaled radius, surface charges at the wall attract counterions and repel co-ions due to electrostatic force. Therefore, an electrical double layer exists between the wall of channel and the solution. The dimension of the electrical double layer is determined by the Debye length in this system, which is typically much smaller than the channel radius. Most of the solution in the channel is electrically neutral due to the shielding effect of the electrical double layer.
In a nanochannel, however, the solution is charged when the dimension of channel radius is smaller than the Debye length. Therefore, it is possible to manipulate the flow of ions inside the nanochannel by introducing surface charges on the wall or by applying an external electrical potential.
Ionic concentration of solution has an important effect on the ion transport. Because a higher concentration leads to a shorter Debye length for the electrical double layer at the channel wall. Its rectifying effect decreases with increasing ionic concentration. On the other hand, ion rectification can be improved by having a dilute solution. | 0 | Theoretical and Fundamental Chemistry |
In a seminal work, G. I. Taylor found the criterion for instability in the presence of viscous forces both experimentally and theoretically. In general, viscous forces are found to postpone the onset of instability, predicted by Rayleigh's criterion. The stability is characterized by three parameters, namely, , and a Taylor number
The first result pertains to the fact that the flow is stable for , consistent with Rayleigh's criterion. However, there are also stable cases in certain parametric range for .
Taylor obtained explicit criterion for the narrow gap in which the annular gap is small compared with the mean radius , or in other words, . A better definition of Taylor number in the thin-gap approximation is
In terms of this Taylor number, the critical condition for same-sense rotation was found to be
As , the critical Taylor number is given by | 1 | Applied and Interdisciplinary Chemistry |
In books on elementary kinetic theory one can find results for dilute gas modeling that are used in many fields. Derivation of the kinetic model for shear viscosity usually starts by considering a Couette flow where two parallel plates are separated by a gas layer. The upper plate is moving at a constant velocity to the right due to a force F. The lower plate is stationary, and an equal and opposite force must therefore be acting on it to keep it at rest. The molecules in the gas layer have a forward velocity component which increase uniformly with distance above the lower plate. The non-equilibrium flow is superimposed on a Maxwell-Boltzmann equilibrium distribution of molecular motions.
Inside a dilute gas in a Couette flow setup, let be the forward velocity of the gas at a horizontal flat layer (labeled as ); is along the horizontal direction. The number of molecules arriving at the area on one side of the gas layer, with speed at angle from the normal, in time interval is
These molecules made their last collision at , where is the mean free path. Each molecule will contribute a forward momentum of
where plus sign applies to molecules from above, and minus sign below. Note that the forward velocity gradient can be considered to be constant over a distance of mean free path.
Integrating over all appropriate velocities within the constraint
yields the forward momentum transfer per unit time per unit area (also known as shear stress):
The net rate of momentum per unit area that is transported across the imaginary surface is thus
Combining the above kinetic equation with Newton's law of viscosity
gives the equation for shear viscosity, which is usually denoted when it is a dilute gas:
Combining this equation with the equation for mean free path gives
Maxwell-Boltzmann distribution gives the average (equilibrium) molecular speed as
where is the most probable speed. We note that
and insert the velocity in the viscosity equation above. This gives the well known equation (with subsequently estimated below) for shear viscosity for dilute gases:
and is the molar mass. The equation above presupposes that the gas density is low (i.e. the pressure is low). This implies that the transport of momentum through the gas due to the translational motion of molecules is much larger than the transport due to momentum being transferred between molecules during collisions. The transfer of momentum between molecules is explicitly accounted for in Revised Enskog theory, which relaxes the requirement of a gas being dilute. The viscosity equation further presupposes that there is only one type of gas molecules, and that the gas molecules are perfect elastic and hard core particles of spherical shape. This assumption of elastic, hard core spherical molecules, like billiard balls, implies that the collision cross section of one molecule can be estimated by
The radius is called collision cross section radius or kinetic radius, and the diameter is called collision cross section diameter or kinetic diameter of a molecule in a monomolecular gas. There are no simple general relation between the collision cross section and the hard core size of the (fairly spherical) molecule. The relation depends on shape of the potential energy of the molecule. For a real spherical molecule (i.e. a noble gas atom or a reasonably spherical molecule) the interaction potential is more like the Lennard-Jones potential or Morse potential which have a negative part that attracts the other molecule from distances longer than the hard core radius. The radius for zero Lennard-Jones potential may then be used as a rough estimate for the kinetic radius. However, using this estimate will typically lead to an erroneous temperature dependency of the viscosity. For such interaction potentials, significantly more accurate results are obtained by numerical evaluation of the required collision integrals.
The expression for viscosity obtained from Revised Enskog Theory reduces to the above expression in the limit of infinite dilution, and can be written as
where is a term that tends to zero in the limit of infinite dilution that accounts for excluded volume, and is a term accounting for the transfer of momentum over a non-zero distance between particles during a collision. | 0 | Theoretical and Fundamental Chemistry |
There is an increasing trend of using ICP-MS as a tool in speciation analysis, which normally involves a front end chromatograph separation and an elemental selective detector, such as AAS and ICP-MS. For example, ICP-MS may be combined with size exclusion chromatography and preparative native PAGE for identifying and quantifying metalloproteins in biofluids. Also the phosphorylation status of proteins can be analyzed.
In 2007, a new type of protein tagging reagents called metal-coded affinity tags (MeCAT) were introduced to label proteins quantitatively with metals, especially lanthanides. The MeCAT labelling allows relative and absolute quantification of all kind of proteins or other biomolecules like peptides. MeCAT comprises a site-specific biomolecule tagging group with at least a strong chelate group which binds metals. The MeCAT labelled proteins can be accurately quantified by ICP-MS down to low attomol amount of analyte which is at least 2–3 orders of magnitude more sensitive than other mass spectrometry based quantification methods. By introducing several MeCAT labels to a biomolecule and further optimization of LC-ICP-MS detection limits in the zeptomol range are within the realm of possibility. By using different lanthanides MeCAT multiplexing can be used for pharmacokinetics of proteins and peptides or the analysis of the differential expression of proteins (proteomics) e.g. in biological fluids. Breakable PAGE SDS-PAGE (DPAGE, dissolvable PAGE), two-dimensional gel electrophoresis or chromatography is used for separation of MeCAT labelled proteins. Flow-injection ICP-MS analysis of protein bands or spots from DPAGE SDS-PAGE gels can be easily performed by dissolving the DPAGE gel after electrophoresis and staining of the gel. MeCAT labelled proteins are identified and relatively quantified on peptide level by MALDI-MS or ESI-MS. | 0 | Theoretical and Fundamental Chemistry |
The development of the temperature profile in the flow is driven by heat transfer determined conditions on the inside surface of the pipe and the fluid. Heat transfer may be a result of a constant heat flux or constant surface temperature. Constant heat flux may be caused by joule heating from a heat source, like heat tape, wrapped around the pipe. Constant temperature conditions may be produced by a phase transition, such as condensation of saturated steam on a pipe surface.
Newtons law of cooling describes convection, the main form of heat transport between the fluid and the pipe:
where
* is the heat flux into the fluid,
* is the convection coefficient,
* is the surface temperature, and
* is the mean stream temperature.
Constant surface heat flux result in becoming a constant as the flow develops and constant surface temperature results in approaching zero. | 1 | Applied and Interdisciplinary Chemistry |
Barlow's formula (called "Kesselformel" in German) relates the internal pressure that a pipe can withstand to its dimensions and the strength of its material.
This approximate formula is named after Peter Barlow, an English mathematician.
where
: : internal pressure,
: : allowable stress,
: : wall thickness,
: : outside diameter.
This formula (DIN 2413) figures prominently in the design of autoclaves and other pressure vessels. | 1 | Applied and Interdisciplinary Chemistry |
Genetic data has been accumulated in databases. Researchers are able to utilize algorithms to decipher the data accessible from databases for the discovery of new processes, targets, and products. The following are databases and tools:
* GenBank database provides genomic datasets for analysis.
* UCSC Genome Browser
* AntiSMASH-DB allows comparing the sequences of newly sequenced BGCs against those of previously predicted and experimentally characterized ones.
* BIG-FAM is a biosynthetic gene cluster family database.
* DoBISCUIT is a database of secondary metabolite biosynthetic gene clusters.
* MIBiG (Minimum Information about a Biosynthetic Gene cluster specification) provides a standard for annotations and metadata on biosynthetic gene clusters and their molecular products.
* Interactive tree of life (iTOL) is a web-based tool for the display, manipulation and annotation of phylogenetic trees. | 1 | Applied and Interdisciplinary Chemistry |
Rhizobia bind to host specific lectins present in root hairs which together with Nod factors lead to the formation of nodulation. Nod factors are recognized by a specific class of receptor kinases that have LysM domains in their extracellular domains. The two LysM (lysin motif) receptor kinases (NFR1 and NFR5) that appear to make up the Nod factor receptor were first isolated in the model legume Lotus japonicus in 2003. They now have been isolated also from soybean and the model legume Medicago truncatula. NFR5 lacks the classical activation loop in the kinase domain. The NFR5 gene lacks introns. First the cell membrane is depolarized and the root hairs start to swell and cell division stops. Nod factor cause the fragmentation and rearrangement of actin network, which coupled with the reinstitution of cell growth lead to the curling of the root hair around the bacteria. This is followed by the localized breakdown of the cell wall and the invagination of the plant cell membrane, allowing the bacterium to form an infection thread. As the infection thread grows the rhizobia travel down its length towards the site of the nodule. During this process the pericycle cells in plants become activated and cells in the inner cortex start growing and become the nodule primordium where the rhizobia infect and differentiate into bacteroids and fix nitrogen. Activation of adjacent middle cortex cells leads to the formation of nodule meristem. | 1 | Applied and Interdisciplinary Chemistry |
Corepressor proteins also bind to the surface of the ligand binding domain of nuclear receptors, but through a LXXXIXXX(I/L) motif of amino acids (where L = leucine, I = isoleucine and X = any amino acid). In addition, compressors bind preferentially to the apo (ligand free) form of the nuclear receptor (or possibly antagonist bound receptor).
* CtBP 602618 (associates with class II histone deacetylases)
* LCoR (ligand-dependent corepressor)
* Nuclear receptor CO-Repressor (NCOR)
** NCOR1 ()
** NCOR2 ()/SMRT (Silencing Mediator (co-repressor) for Retinoid and Thyroid-hormone receptors) (associates with histone deacetylase-3)
* Rb (retinoblastoma protein) (associates with histone deacetylase-1 and -2)
* RCOR (REST corepressor)
** RCOR1 ()
** RCOR2 ()
** RCOR3 ()
* Sin3
** SIN3A ()
** SIN3B ()
* TIF1 (transcriptional intermediary factor 1)
** TRIM24 Tripartite motif-containing 24 ()
** TRIM28 Tripartite motif-containing 28 ()
** TRIM33 Tripartite motif-containing 33 () | 1 | Applied and Interdisciplinary Chemistry |
ePaint is a less-toxic alternative to conventional antifouling marine paints that generates hydrogen peroxide.
Photocatalysis of organic reactions by polypyridyl complexes, porphyrins, or other dyes can produce materials inaccessible by classical approaches. Most photocatalytic dye degradation studies have employed . The anatase form of has higher photon absorption characteristics. | 0 | Theoretical and Fundamental Chemistry |
Due to Brownian motion particles randomly move through the liquid. And hence better transport of heat.
Although it was originally believed that the fluid motions resulting from Brownian motion of the nanoparticles could explain the enhancement in heat transfer properties, this hypothesis was later rejected. | 0 | Theoretical and Fundamental Chemistry |
In this regime, the benefit of flexibility is most pronounced. The characteristic plate length is significantly longer than the characteristic depth to which the plate is submerged beneath the water line. As a result, the narrowing column above the plate is negligible, which the additional displacement of water due to bending is significant. | 1 | Applied and Interdisciplinary Chemistry |
Thermoresponsive polymers can be used as stationary phase in liquid chromatography. Here, the polarity of the stationary phase can be varied by temperature changes, altering the power of separation without changing the column or solvent composition. Thermally related benefits of gas chromatography can now be applied to classes of compounds that are restricted to liquid chromatography due to their thermolability. In place of solvent gradient elution, thermoresponsive polymers allow the use of temperature gradients under purely aqueous isocratic conditions. The versatility of the system is controlled not only through changing temperature, but through the addition of modifying moieties that allow for a choice of enhanced hydrophobic interaction, or by introducing the prospect of electrostatic interaction. These developments have already introduced major improvements to the fields of hydrophobic interaction chromatography, size exclusion chromatography, ion exchange chromatography, and affinity chromatography separations as well as pseudo-solid phase extractions ("pseudo" because of phase transitions). | 0 | Theoretical and Fundamental Chemistry |
Acetals, imines, and enamines can be converted back into ketones by treatment with excess water under acid-catalyzed conditions: ; ; . | 0 | Theoretical and Fundamental Chemistry |
Methyl isocyanate is a colorless, poisonous, lachrymatory (tearing agent), flammable liquid. It is soluble in water to 6–10 parts per 100 parts, but it also reacts with water (see Reactions below).
It has a refractive index of 1.363 with a wavelength of 589 nm at a temperature of 20 °C | 0 | Theoretical and Fundamental Chemistry |
Jason S. Lewis was born and raised in Horndean, Hampshire, England. Lewis received his Bachelor of Science in chemistry, B.Sc. from the University of Essex in 1992. He received his Master of Science in chemistry from the University of Essex in 1993.
In 1996, he received his Doctor of Philosophy in Biochemistry at the University of Kent. | 0 | Theoretical and Fundamental Chemistry |
The primary structure of RiAFP (the sequence may be found [https://www.ncbi.nlm.nih.gov/protein/313766639 here]) determined by Mass Spectroscopy, Edman degradation and by constructing a partial cDNA sequence and PCR have shown that a TxTxTxT internal repeat exists. Sequence logos constructed from the RiAFP internal repeats, have been particularly helpful in the determination of the consensus sequence of these repeats. The TxTxTxT domains are irregularly spaced within the protein and have been shown to be conserved from the TxT binding motif of other AFPs. The hydroxyl moiety of the T residues fits well, when spaced as they are in the internal repeats, with the hydroxyl moieties of externally facing water molecules in the forming ice lattice. This mimics the formation of the growth cone at a nucleation site in the absence of AFPs. Thus, the binding of RiAFP inhibits the growth of the crystal in the basal and prism planes of the ice. | 1 | Applied and Interdisciplinary Chemistry |
The mound is left to rest for several months before planting, although some advise immediate planting.
Anything can be grown on the raised beds, but if the bed will decompose/release its nutrients quickly (so long as it is not made of bulky materials like tree trunks), more demanding crops such as pumpkins, zucchini, cucumbers, cabbages, tomatoes, sweet corn, celery, or potatoes are grown in the first year, after which the bed is used for less demanding crops like beans, peas, and strawberries. | 1 | Applied and Interdisciplinary Chemistry |
The C-terminal domain, also known as ropB-CTD, is a carboxy terminalligand-binding domain made of amino acids 56–280. RopB-CTD houses 5 TPR motifs and attaches to the SIP peptide in the innermost part of the SIP binding pocket in a sequence-specific manner without induction of polymerization. | 1 | Applied and Interdisciplinary Chemistry |
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