text
stringlengths 105
4.57k
| label
int64 0
1
| label_text
stringclasses 2
values |
|---|---|---|
The Geochemical Society is a nonprofit scientific organization founded to encourage the application of chemistry to solve problems involving geology and cosmology. The society promotes understanding of geochemistry through the annual Goldschmidt Conference, publication of a peer-reviewed journal and electronic newsletter, awards programs recognizing significant accomplishments in the field, and student development programs. The society's offices are located on the campus of the Carnegie Institution for Science in Washington, DC. | 0 | Theoretical and Fundamental Chemistry |
In the case of an idealized two-level atom the detailed balance for the emission and absorption which preserves the Planck formula for the black-body radiation leads to equality of cross-section of absorption and emission. In the solid-state lasers the splitting of each of laser levels leads to the broadening which greatly exceeds the natural spectral linewidth. In the case of an ideal two-level atom, the product of the linewidth and the lifetime is of order of unity, which obeys the Heisenberg uncertainty principle. In solid-state laser materials, the linewidth is several orders of magnitude larger so the spectra of emission and absorption are determined by distribution of excitation among sublevels rather than by the shape of the spectral line of each individual transition between sublevels. This distribution is determined by the effective temperature within each of laser levels. The McCumber hypothesis is that the distribution of excitation among sublevels is thermal. The effective temperature determines the spectra of emission and absorption ( The effective temperature is called a temperature by scientists even if the excited medium as whole is pretty far from the thermal state ) | 0 | Theoretical and Fundamental Chemistry |
Diisopinocampheylborane was originally prepared by hydroboration of excess α-pinene with borane,
but it is now more commonly generated from borane-methyl sulfide (BMS).
The compound can be isolated as a solid, but because it is quite sensitive to water and air, it is often generated in situ and used as a solution. The synthesis is complicated by a number of factors, including the tendency of the compound to eliminate pinene.
Diisopinocampheylborane is often represented as a monomer (including in this article), but X-ray crystallography establishes a dimeric structure. | 0 | Theoretical and Fundamental Chemistry |
The term dilution assay is generally used to designate a special type of bioassay in which one or more preparations (e.g. a drug) are administered to experimental units at different dose levels inducing a measurable biological response. The dose levels are prepared by dilution in a diluent that is inert in respect of the response. The experimental units can for example be cell-cultures, tissues, organs or living animals. The biological response may be quantal (e.g. positive/negative) or quantitative (e.g. growth). The goal is to relate the response to the dose, usually by interpolation techniques, and in many cases to express the potency/activity of the test preparation(s) relative to a standard of known potency/activity.
Dilution assays can be direct or indirect. In a direct dilution assay the amount of dose needed to produce a specific (fixed) response is measured, so that the dose is a stochastic variable defining the tolerance distribution. Conversely, in an indirect dilution assay the dose levels are administered at fixed dose levels, so that the response is a stochastic variable.
In some assays, there may be strong reasons for believing that all the constituents of the test preparation except one, are without any effect on the studied response of the subjects. An assay of the preparation against a standard preparation of the effective constituent, is then equivalent to an analysis for determining the content of the constituent. This may be described as analytical dilution assay. | 1 | Applied and Interdisciplinary Chemistry |
The redox mechanism involves a change in the oxidation state of the catalytic material. In this mechanism, CO is oxidized by an O-atom intrinsically belonging to the catalytic material to form CO. A water molecule undergoes dissociative adsorption at the newly formed O-vacancy to yield two hydroxyls. The hydroxyls disproportionate to yield H and return the catalytic surface back to its pre-reaction state. | 0 | Theoretical and Fundamental Chemistry |
In India, the Ayurveda is traditional medicine that emphasizes plant-based treatments, hygiene, and balance in the body's state of being. Indian materia medica included knowledge of plants, where they grow in all season, methods for storage and shelf life of harvested materials. It also included directions for making juice from vegetables, dried powders from herb, cold infusions and extracts. | 1 | Applied and Interdisciplinary Chemistry |
Exposure to UV radiation is associated with skin aging, wrinkle production, liver spots, loss of skin elasticity, erythema (reddening of the skin), sunburn, photokeratitis (snow blindness), ocular melanoma (eye cancer), and infections. Tanning beds can contain many microbes, some of which are pathogens that can cause skin infections and gastric distress. In one study in New York in 2009, the most common pathogens found on tanning beds were Pseudomonas spp. (aeruginosa and putida), Bacillus spp., Klebsiella pneumoniae, Enterococcus species, Staphylococcus aureus, and Enterobacter cloacae. Several prescription and over-the-counter drugs, including antidepressants, antibiotics, antifungals and anti-diabetic medication, can cause photosensitivity, which makes burning the skin while tanning more likely. This risk is increased by a lack of staff training in tanning facilities. | 0 | Theoretical and Fundamental Chemistry |
A GeneRIF or Gene Reference Into Function is a short (255 characters or fewer) statement about the function of a gene. GeneRIFs provide a simple mechanism for allowing scientists to add to the functional annotation of genes described in the Entrez Gene database. In practice, function is constructed quite broadly. For example, there are GeneRIFs that discuss the role of a gene in a disease, GeneRIFs that point the viewer towards a review article about the gene, and GeneRIFs that discuss the structure of a gene. However, the stated intent is for GeneRIFs to be about gene function. Currently over half a million geneRIFs have been created for genes from almost 1000 different species.
GeneRIFs are always associated with specific entries in the Entrez Gene database. Each GeneRIF has a pointer to the PubMed ID (a type of document identifier) of a scientific publication that provides evidence for the statement made by the GeneRIF. GeneRIFs are often extracted directly from the document that is identified by the PubMed ID, very frequently from its title or from its final sentence.
GeneRIFs are usually produced by NCBI indexers, but anyone may submit a GeneRIF.
To be processed, a valid Gene ID must exist for the specific gene, or the Gene staff must have assigned an overall Gene ID to the species. The latter case is implemented via records in Gene with the symbol NEWENTRY. Once the Gene ID is identified, only three types of information are required to complete a submission:
# a concise phrase describing a function or functions (less than 255 characters in length, preferably more than a restatement of the title of the paper);
# a published paper describing that function, implemented by supplying the PubMed ID of a citation in PubMed;
# a valid e-mail address (which will remain confidential). | 1 | Applied and Interdisciplinary Chemistry |
PBS has many uses because it is isotonic and non-toxic to most cells. These uses include substance dilution and cell container rinsing. PBS with EDTA is also used to disengage attached and clumped cells. Divalent metals such as zinc, however, cannot be added as this will result in precipitation. For these types of applications, Good's buffers are recommended. PBS has been shown to be an acceptable alternative to viral transport medium regarding transport and storage of RNA viruses, such as SARS-CoV-2. | 1 | Applied and Interdisciplinary Chemistry |
Hydrochloric acid regeneration or HCl regeneration is a chemical process for the reclamation of bound and unbound HCl from metal chloride solutions such as hydrochloric acid. | 0 | Theoretical and Fundamental Chemistry |
The Illinois Soil Nitrogen Test ("ISNT") is a method for measuring the amount of Nitrogen in soil that is available for use by plants as a nutrient. The test predicts whether the addition of nitrogen fertilizer to agricultural land will result in increased crop yields.
Nitrogen is essential for plant development. Indeed, for crops that are destined to be food for farm animal or human consumption, incorporation of nitrogen into the crop is an important goal, since this forms the basis for protein in the human diet.
Nitrogen is commonly present in soils in many forms, and there are many ways to measure this nitrogen. None of these are completely satisfactory as a measure of the nitrogen that is available for use by crops. The ISNT is a new (2007) method for measuring nitrogen available for plant uptake.
ISNT estimates the amount of nitrogen present in the soil as amino sugar nitrogen. With respect to corn and soybeans, the optimal range for plant growth appears to be around 225 to 240 mg/Kg. Some form of nitrogen fertilizer is needed if levels are below this range. On the other hand, if levels are above this range, addition of nitrogen fertilizer will not increase crop yield.
In the corn belt, since about 1975, the predominant method of estimating the amount of nitrogen needed for corn has been the "yield-based" method. A farmer first estimates the yield of corn he intends to produce. He then applies 1.1 to 1.4 lbs of nitrogen per bushel of expected yield. ISNT represents an alternative approach to managing nitrogen application. However, ISNT does not offer a simple answer as to the amount of nitrogen fertilizer that is needed, or as to the optimal form of that fertilizer.
In field trials in Illinois, some fields have been found to be under-fertilized when managed according to the "yield-based" method, as judged by the ISNT. In the majority of trials, however, the yield-based method calls for the addition of nitrogen far in excess of the levels needed for optimal crop production. This nitrogen, which is applied by farmers at great cost, does not find its way into the crop, but is lost to the atmosphere or leaches into waterways.
Within the corn belt, stalks and other crop residues are left in the field with the intention of enhancing the amount of organic material in the soil. Excessive nitrogen application, however, appears to promote the rapid decomposition of organic matter in the soil, resulting in release of carbon dioxide. As a result, the amount of organic material in soils managed according to the yield-based method in the corn belt appears to be decreasing in spite of the large amounts of crop residues left in the fields. | 0 | Theoretical and Fundamental Chemistry |
In addition to yttrium, a wide range of rare-earth elements from Nd to Lu, except for Eu, can form REB compounds. Seybolt discovered the compound YB in 1960 and its structure was solved by Richards and Kasper in 1969. They reported that YB has a face-centered cubic structure with space group Fmc (No. 226) and lattice constant a = 2.3440(6) nm. There are 13 boron sites B1–B13 and one yttrium site. The B1 sites form one icosahedron and the B2–B9 sites make up another icosahedron. These icosahedra arrange in a thirteen-icosahedron unit (B)B which is shown in figure 4a and is called supericosahedron. The icosahedron formed by the B1 site atoms is located at the center of the supericosahedron. The supericosahedron is one of the basic units of the boron framework of YB. There are two types of supericosahedra: one occupies the cubic face centers and another, which is rotated by 90°, is located at the center of the cell and at the cell edges. Thus, there are eight supericosahedra (1248 boron atoms) in the unit cell.
Another structure unit of YB, shown in figure 4b, is B cluster of 80 boron sites formed by the B10 to B13 sites. All those 80 sites are partially occupied and in total contain only about 42 boron atoms. The B cluster is located at the body center of the octant of the unit cell, i.e., at the 8a position (1/4, 1/4, 1/4); thus, there are eight such clusters (336 boron atoms) per unit cell. Two independent structure analyses came to the same conclusion that the total number of boron atoms in the unit cell is 1584. The boron framework structure of YB is shown in figure 5a. To indicate relative orientations of the supericosahedra, a schematic drawing is shown in figure 5b, where the supericosahedra and the B clusters are depicted by light green and dark green spheres, respectively; at the top surface of the unit cell, the relative orientations of the supericosahedra are indicated by arrows. There are 48 yttrium sites ((0.0563, 1/4, 1/4) for YB) in the unit cell. Richards and Kasper fixed the Y site occupancy to 0.5 that resulted in 24 Y atoms in the unit cell and the chemical composition of YB. As shown in figure 6, Y sites form a pair separated by only 0.264 nm in YB. This pair is aligned normal to the plane formed by four supericosahedra. The Y site occupancy 0.5 implies that the pair has always one Y atom with one empty site.
Slack et al. reported that the total number of boron atoms in the unit cell, calculated from the measured values of density, chemical composition and lattice constant, is 1628 ± 4, which is larger than the value 1584 obtained from the structural analysis. The number of B atoms in the unit cell remains nearly constant when the chemical composition changes from YB to YB. On the other hand, the total number of yttrium atoms per unit cell varies, and it is, for example, ~26.3 for YB (see right table). If the total number of Y atoms stays below or equal to 24 then it is possible that one Y atom accommodates in each Y pair (partial occupancy). However, the experimental value of 26.3 significantly exceeds 24, and thus both pair sites might be occupied. In this case, because of the small separation between the two Y atoms, they must be repelled by the Coulomb force. To clarify this point, split Y sites were introduced in the structure analysis resulting in a better agreement with the experiment. The Y site distances and occupancies are presented in the left table.
There are twenty Y pair sites with one Y atom and three pairs with two Y atoms; there is also one empty Y pair (partial occupancy = 0). The separation 0.340 nm for the Y2 pair site (two Y atoms in the pair site) is much larger than the separation 0.254 nm for the Y1 pair site (one Y atom in the pair site), as expected. The total number of Y atoms in the unit cell is 26.3, exactly as measured. Both cases are compared in figure 7. The larger separation for the Y2 pair site is clear as compared with that for the Y1 pair site. In case of the Y2 pair, some neighboring boron sites that belong to the B cluster must be unoccupied because they are too close to the Y2 site.
Splitting the Y site yields right number of Y atoms in the unit cell, but not B atoms. Not only the occupation of the B sites in the B cluster must be strongly dependent on whether or not the Y site is the Y1 state or the Y2 state, but also the position of the occupied B sites must be affected by the state of the Y site. Atomic coordinates and site occupancies are summarized in table II. | 0 | Theoretical and Fundamental Chemistry |
Fluoroethyl fluoroacetate, or more accurately 2-fluoroethyl fluoroacetate, is an organic compound with the chemical formula . It is the fluoroacetate ester of 2-fluoroethanol, or in other words, the 2-fluoroethyl ester of fluoroacetic acid. 2-Fluoroethyl fluoroacetate is two times more toxic than methyl fluoroacetate. | 1 | Applied and Interdisciplinary Chemistry |
The thermal entrance length is the distance for incoming flow in a pipe to form a temperature profile with a stable shape. The shape of the fully developed temperature profile is determined by temperature and heat flux conditions along the inside wall of the pipe, as well as fluid properties. | 1 | Applied and Interdisciplinary Chemistry |
In chemistry and particularly biochemistry, an energy-rich species (usually energy-rich molecule) or high-energy species (usually high-energy molecule) is a chemical species which reacts, potentially with other species found in the environment, to release chemical energy.
In particular, the term is often used for:
* adenosine triphosphate (ATP) and similar molecules called high-energy phosphates, which release inorganic phosphate into the environment in an exothermic reaction with water:
:ATP + → ADP + P ΔG°' = −30.5 kJ/mol (−7.3 kcal/mol)
* fuels such as hydrocarbons, carbohydrates, lipids, proteins, and other organic molecules which react with oxygen in the environment to ultimately form carbon dioxide, water, and sometimes nitrogen, sulfates, and phosphates
* molecular hydrogen
* monatomic oxygen, ozone, hydrogen peroxide, singlet oxygen and other metastable or unstable species which spontaneously react without further reactants
* in particular, the vast majority of free radicals
* explosives such as nitroglycerin and other substances which react exothermically without requiring a second reactant
* metals or metal ions which can be oxidized to release energy
This is contrasted to species that are either part of the environment (this sometimes includes diatomic triplet oxygen) or do not react with the environment (such as many metal oxides or calcium carbonate); those species are not considered energy-rich or high-energy species. | 1 | Applied and Interdisciplinary Chemistry |
Raoults law is a phenomenological relation that assumes ideal behavior based on the simple microscopic assumption that intermolecular forces between unlike molecules are equal to those between similar molecules, and that their molar volumes are the same: the conditions of an ideal solution. This is analogous to the ideal gas law, which is a limiting law valid when the interactive forces between molecules approach zero, for example as the concentration approaches zero. Raoults law is instead valid if the physical properties of the components are identical. The more similar the components are, the more their behavior approaches that described by Raoults law. For example, if the two components differ only in isotopic content, then Raoults law is essentially exact.
Comparing measured vapor pressures to predicted values from Raoult's law provides information about the true relative strength of intermolecular forces. If the vapor pressure is less than predicted (a negative deviation), fewer molecules of each component than expected have left the solution in the presence of the other component, indicating that the forces between unlike molecules are stronger. The converse is true for positive deviations.
For a solution of two liquids A and B, Raoult's law predicts that if no other gases are present, then the total vapor pressure above the solution is equal to the weighted sum of the "pure" vapor pressures and of the two components. Thus the total pressure above the solution of A and B would be
Since the sum of the mole fractions is equal to one,
This is a linear function of the mole fraction , as shown in the graph. | 0 | Theoretical and Fundamental Chemistry |
Consider the case of a solid sphere moving in a stationary liquid with a constant velocity.
The liquid is modeled as an incompressible fluid (i.e. with constant density), and being stationary means that its velocity tends towards zero as the distance from the sphere approaches infinity.
For a real body there will be a transient effect due to its acceleration as it begins its motion; however after enough time it will tend towards zero, so that the fluid velocity everywhere will approach the one obtained in the hypothetical case in which the body is already moving for infinite time.
Thus we assume a sphere of radius a moving at a constant velocity , in an incompressible fluid that is at rest at infinity. We will work in coordinates that move along with the sphere with the coordinate center located at the sphere's center. We have:
Since these boundary conditions, as well as the equation of motions, are time invariant (i.e. they are unchanged by shifting the time ) when expressed in the coordinates, the solution depends upon the time only through these coordinates.
The equations of motion are the Navier-Stokes equations defined in the resting frame coordinates . While spatial derivatives are equal in both coordinate systems, the time derivative that appears in the equations satisfies:
where the derivative is with respect to the moving coordinates . We henceforth omit the m subscript.
Oseen's approximation sums up to neglecting the term non-linear in . Thus the incompressible Navier-Stokes equations become:
for a fluid having density ρ and kinematic viscosity ν = μ/ρ (μ being the dynamic viscosity). p is the pressure.
Due to the continuity equation for incompressible fluid , the solution can be expressed using a vector potential . This turns out to be directed at the direction and its magnitude is equivalent to the stream function used in two-dimensional problems. It turns out to be:
where is Reynolds number for the flow close to the sphere.
Note that in some notations is replaced by so that the derivation of from is more similar to its derivation from the stream function in the two-dimensional case (in polar coordinates). | 1 | Applied and Interdisciplinary Chemistry |
For a planet around another star, (the incident stellar flux on the planet) is not a readily measurable quantity. To find the equilibrium temperature of such a planet, it may be useful to approximate the host star's radiation as a blackbody as well, such that:
The luminosity () of the star, which can be measured from observations of the star's apparent brightness, can then be written as:
where the flux has been multiplied by the surface area of the star.
To find the incident stellar flux on the planet, , at some orbital distance from the star, , one can divide by the surface area of a sphere with radius :
Plugging this into the general equation for planetary equilibrium temperature gives:
If the luminosity of the star is known from photometric observations, the other remaining variables that must be determined are the Bond albedo and orbital distance of the planet. Bond albedos of exoplanets can be constrained by flux measurements of transiting exoplanets, and may in future be obtainable from direct imaging of exoplanets and a conversion from geometric albedo. Orbital properties of the planet such as the orbital distance can be measured through radial velocity and transit period measurements.
Alternatively, the planetary equilibrium may be written in terms of the temperature and radius of the star: | 0 | Theoretical and Fundamental Chemistry |
Glass properties and glass behavior during production can be calculated through statistical analysis of glass databases such as GE-SYSTEM
SciGlass and Interglad,
sometimes combined with the finite element method. For estimating the melting enthalpy thermodynamic databases are used. | 0 | Theoretical and Fundamental Chemistry |
These photosystems are light-driven redox centers, each consisting of an antenna complex that uses chlorophylls and accessory photosynthetic pigments such as carotenoids and phycobiliproteins to harvest light at a variety of wavelengths. Each antenna complex has between 250 and 400 pigment molecules and the energy they absorb is shuttled by resonance energy transfer to a specialized chlorophyll a at the reaction center of each photosystem. When either of the two chlorophyll a molecules at the reaction center absorb energy, an electron is excited and transferred to an electron-acceptor molecule. Photosystem I contains a pair of chlorophyll a molecules, designated P700, at its reaction center that maximally absorbs 700 nm light. Photosystem II contains P680 chlorophyll that absorbs 680 nm light best (note that these wavelengths correspond to deep red – see the visible spectrum). The P is short for pigment and the number is the specific absorption peak in nanometers for the chlorophyll molecules in each reaction center. This is the green pigment present in plants that is not visible to unaided eyes. | 0 | Theoretical and Fundamental Chemistry |
On a phase space and over a time interval , consider a non-autonomous dynamical system defined through the flow map , mapping initial conditions into their position for any time . If the flow map is a diffeomorphism for any choice of , then for any smooth set of initial conditions in , the set
is an invariant manifold in the extended phase space . Borrowing terminology from fluid dynamics, we refer to the evolving time slice of the manifold as a material surface (see Fig. 1). Since any choice of the initial condition set yields an invariant manifold , invariant manifolds and their associated material surfaces are abundant and generally undistinguished in the extended phase space. Only few of them will act as cores of coherent trajectory patterns. | 1 | Applied and Interdisciplinary Chemistry |
Many biological proteins and enzymes can possess more than one binding site.
Usually, when a ligand binds with a macromolecule , it can influence binding kinetics of other ligands binding to the macromolecule.
A simplified mechanism can be formulated if the affinity of all binding sites can be considered independent of the number of ligands bound to the macromolecule.
This is valid for macromolecules composed of more than one, mostly identical, subunits. It can be then assumed that each of these subunits are identical, symmetric and that they possess only a single binding site. Then the concentration of bound ligands becomes
In this case, , but comprises all partially saturated forms of the macromolecule:
where the saturation occurs stepwise
For the derivation of the general binding equation a saturation function is defined as the quotient from the portion of bound ligand to the total
amount of the macromolecule:
K′ are so-called macroscopic or apparent dissociation constants and can result from multiple individual reactions. For example, if a macromolecule M has three binding sites, K′ describes a ligand being bound to any of the three binding sites. In this example, K′ describes two molecules being bound and K′ three molecules being bound to the macromolecule. The microscopic or individual dissociation constant describes the equilibrium of ligands binding to specific binding sites. Because we assume identical binding sites with no cooperativity, the microscopic dissociation constant must be equal for every binding site and can be abbreviated simply as K. In our example, K′ is the amalgamation of a ligand binding to either of the three possible binding sites (I, II and III), hence three microscopic dissociation constants and three distinct states of the ligand–macromolecule complex. For K′ there are six different microscopic dissociation constants (I–II, I–III, II–I, II–III, III–I, III–II) but only three distinct states (it does not matter whether you bind pocket I first and then II or II first and then I). For K′ there are three different dissociation constants — there are only three possibilities for which pocket is filled last (I, II or III) — and one state (I–II–III).
Even when the microscopic dissociation constant is the same for each individual binding event, the macroscopic outcome (K′, K′ and K′) is not equal. This can be understood intuitively for our example of three possible binding sites. K′ describes the reaction from one state (no ligand bound) to three states (one ligand bound to either of the three binding sides). The apparent K′ would therefore be three times smaller than the individual K. K′ describes the reaction from three states (one ligand bound) to three states (two ligands bound); therefore, K′ would be equal to K. K′ describes the reaction from three states (two ligands bound) to one state (three ligands bound); hence, the apparent dissociation constant K′ is three times bigger than the microscopic dissociation constant K.
The general relationship between both types of dissociation constants for n binding sites is
Hence, the ratio of bound ligand to macromolecules becomes
where is the binomial coefficient.
Then the first equation is proved by applying the binomial rule | 0 | Theoretical and Fundamental Chemistry |
A Belousov–Zhabotinsky reaction is one of several oscillating chemical systems, whose common element is the inclusion of bromine and an acid. An essential aspect of the BZ reaction is its so-called "excitability" — under the influence of stimuli, patterns develop in what would otherwise be a perfectly quiescent medium. Some clock reactions such as the Briggs–Rauscher reactions and the BZ using the chemical ruthenium bipyridyl as catalyst can be excited into self-organising activity through the influence of light.
Boris Belousov first noted, sometime in the 1950s, that in a mix of potassium bromate, cerium(IV) sulfate, propanedioic acid (another name for malonic acid) and citric acid in dilute sulfuric acid, the ratio of concentration of the cerium(IV) and cerium(III) ions oscillated, causing the colour of the solution to oscillate between a yellow solution and a colorless solution. This is due to the cerium(IV) ions being reduced by propanedioic acid to cerium(III) ions, which are then oxidized back to cerium(IV) ions by bromate(V) ions. | 1 | Applied and Interdisciplinary Chemistry |
Margot Dorenfeldt (1895–1986) was the first woman to graduate from Norwegian Institute of Technology (1919) and specialized in inorganic chemistry and electrochemistry. She published several papers in radiochemistry. | 0 | Theoretical and Fundamental Chemistry |
The gene is located on the short arm of chromosome 2 (2p13.2) on the plus (Watson) strand. It is 224,161 bases in length organised into 23 exons. The encoded protein has 4,167 amino acids and molecular weight of 460,937 Da. Three isoforms are known. The protein itself has a large tandem-repeat domain comprising 34 imperfect repetitions of 47 amino acids. Mutations associated with disease are usually found in exons 8, 10 and 16.
The gene is expressed in fetal tissues including the aorta, brain, eye, kidney, liver, lung, olfactory bulb, pancreas, skeletal muscle, spleen and testis. The protein is found in the cytoplasm, centrosome, cell projections and cilium basal body. During mitosis it localizes to both spindle poles. | 1 | Applied and Interdisciplinary Chemistry |
A nickel sulfide inclusion, (also abbreviated to NiS), occurs during the process of manufacturing float glass (normal window glass). | 0 | Theoretical and Fundamental Chemistry |
This method starts with a solution of hydrogen peroxide and sulfuric acid. To this a solution containing potassium iodide, sodium thiosulfate, and starch is added. There are two reactions occurring simultaneously in the solution.
In the first, slow reaction, iodine is produced:
In the second, fast reaction, iodine is reconverted to two iodide ions by the thiosulfate:
After some time the solution always changes color to a very dark blue, almost black.
When the solutions are mixed, the second reaction causes the iodine to be consumed much faster than it is generated, and only a small amount of iodine is present in the dynamic equilibrium. Once the thiosulfate ion has been exhausted, this reaction stops and the blue colour caused by the iodine – starch complex appears.
Anything that accelerates the first reaction will shorten the time until the solution changes color. Decreasing the pH (increasing concentration), or increasing the concentration of iodide or hydrogen peroxide will shorten the time. Adding more thiosulfate will have the opposite effect; it will take longer for the blue colour to appear.
Aside from using sodium thiosulfate as a substrate, cysteine can also be used.
Iodide from potassium iodide is converted to iodine in the first reaction:
2 + 2 H + HO → I + 2 HO
The iodine produced in the first reaction is reduced back to iodide by the reducing agent, cysteine. At the same time, cysteine is oxidized into cystine.
2 CHNOS + I → CHNOS + 2 + 2 H
Similar to thiosulfate case, when cysteine is exhausted, the blue color appears. | 0 | Theoretical and Fundamental Chemistry |
In geometry, Hermann–Mauguin notation is used to represent the symmetry elements in point groups, plane groups and space groups. It is named after the German crystallographer Carl Hermann (who introduced it in 1928) and the French mineralogist Charles-Victor Mauguin (who modified it in 1931). This notation is sometimes called international notation, because it was adopted as standard by the International Tables For Crystallography since their first edition in 1935.
The Hermann–Mauguin notation, compared with the Schoenflies notation, is preferred in crystallography because it can easily be used to include translational symmetry elements, and it specifies the directions of the symmetry axes. | 0 | Theoretical and Fundamental Chemistry |
The Taylor column is an imaginary cylinder projected above and below a real cylinder that has been placed parallel to the rotation axis (anywhere in the flow, not necessarily in the center). The flow will curve around the imaginary cylinders just like the real due to the Taylor–Proudman theorem, which states that the flow in a rotating, homogeneous, inviscid fluid are 2-dimensional in the plane orthogonal to the rotation axis and thus there is no variation in the flow along the axis, often taken to be the axis.
The Taylor column is a simplified, experimentally observed effect of what transpires in the Earth's atmospheres and oceans. | 1 | Applied and Interdisciplinary Chemistry |
In organic chemistry an enol ether is an alkene with an alkoxy substituent. The general structure is RC=CR-OR where R = H, alkyl or aryl. A common subfamily of enol ethers are vinyl ethers, with the formula ROCH=CH. Important enol ethers include the reagent 3,4-dihydropyran and the monomers methyl vinyl ether and ethyl vinyl ether. | 0 | Theoretical and Fundamental Chemistry |
Here the solvent travels up the chromatographic paper. Both descending and ascending paper chromatography are used for the separation of organic and inorganic substances.
The sample and solvent move upward. | 0 | Theoretical and Fundamental Chemistry |
The atmosphere contains three main gases, namely oxygen, carbon dioxide (CO) and nitrogen. In the atmosphere, oxygen is 20%, nitrogen is 79% and CO is 0.15% to 0.65% by volume. CO increases with the increase in the depth of soil because of decomposition of accumulated organic matter and abundance of plant roots. The presence of oxygen in the soil is important because it helps in breaking down insoluble rocky mass into soluble minerals and organic humification. Air in the soil is composed of gases that are present in the atmosphere, but not in the same proportions. These gases facilitate chemical reactions in microorganisms. Accumulation of soluble nutrients in the soil makes it more productive. If the soil is deficient in oxygen, microbial activity is slowed down or eliminated. Important factors controlling the soil atmosphere are temperature, atmospheric pressure, wind/aeration and rainfall. | 0 | Theoretical and Fundamental Chemistry |
The process of forming diazonium compounds is called "diazotation", "diazoniation", or "diazotization". The reaction was first reported by Peter Griess in 1858, who subsequently discovered several reactions of this new class of compounds. Most commonly, diazonium salts are prepared by treatment of aromatic amines with nitrous acid and additional acid. Usually the nitrous acid is generated in situ (in the same flask) from sodium nitrite and the excess mineral acid (usually aqueous HCl, , p-, or ):
Chloride salts of diazonium cation, traditionally prepared from the aniline, sodium nitrite, and hydrochloric acid, are unstable at room temperature and are classically prepared at 0 – 5 °C. However, one can isolate diazonium compounds as tetrafluoroborate or tosylate salts, which are stable solids at room temperature. It is often preferred that the diazonium salt remain in solution, but they do tend to supersaturate. Operators have been injured or even killed by an unexpected crystallization of the salt followed by its detonation.
Due to these hazards, diazonium compounds are often not isolated. Instead they are used in situ. This approach is illustrated in the preparation of an arenesulfonyl compound: | 0 | Theoretical and Fundamental Chemistry |
Pierre Curie ( , ; 15 May 1859 – 19 April 1906) was a French physicist, a pioneer in crystallography, magnetism, piezoelectricity, and radioactivity. In 1903, he received the Nobel Prize in Physics with his wife, Marie Skłodowska–Curie, and Henri Becquerel, "in recognition of the extraordinary services they have rendered by their joint researches on the radiation phenomena discovered by Professor Henri Becquerel". With their win, the Curies became the first ever married couple to win the Nobel Prize, launching the Curie family legacy of five Nobel Prizes. | 1 | Applied and Interdisciplinary Chemistry |
Different 2A peptides have different efficiencies of self-cleaving, T2A and P2A being the most and F2A the least efficient. Therefore, up to 50% of F2A-linked proteins can remain in the cell as a fusion protein, which might cause some unpredictable outcomes, including a gain of function. One study reported that 2A sites cause the ribosome to fall off approximately 60% of the time, and that, together with ribosome read-through of about 10% for P2A and T2A, this results in reducing expression of the downstream peptide chain by about 70%. However, the level of drop-off detected in this study varied widely depending on the exact construct used, with some constructs showing little evidence of drop-off; furthermore, within a tri-cistronic transcript it reported a higher level of ribosome drop-off after one 2A sequence than after two 2As combined, which is at odds with a linear model of translation. | 1 | Applied and Interdisciplinary Chemistry |
The zone rouge (English: red zone) is a chain of non-contiguous areas throughout northeastern France that the French government isolated after the First World War. The land, which originally covered more than , was deemed too physically and environmentally damaged by conflict for human habitation. Rather than attempt to immediately clean up the former battlefields, the land was allowed to return to nature. Restrictions within the Zone Rouge still exist today, although the control areas have been greatly reduced.
The zone rouge was defined just after the war as "Completely devastated. Damage to properties: 100%. Damage to Agriculture: 100%. Impossible to clean. Human life impossible".
Under French law, activities such as housing, farming, or forestry were temporarily or permanently forbidden in the Zone Rouge, because of the vast amounts of human and animal remains, and millions of items of unexploded ordnance contaminating the land. Some towns and villages were never permitted to be rebuilt after the war. | 1 | Applied and Interdisciplinary Chemistry |
All-trans-retinal is also an essential component of microbial opsins such as bacteriorhodopsin, channelrhodopsin, and halorhodopsin, which are important in bacterial and archaeal anoxygenic photosynthesis. In these molecules, light causes the all-trans-retinal to become 13-cis retinal, which then cycles back to all-trans-retinal in the dark state. These proteins are not evolutionarily related to animal opsins and are not GPCRs; the fact that they both use retinal is a result of convergent evolution. | 1 | Applied and Interdisciplinary Chemistry |
The Bessemer Gold Medal is awarded annually by the Institute of Materials, Minerals and Mining (IOM3) "for outstanding services to the steel industry, to the inventor or designer of any significant innovation in the process employed in the manufacture of steel, or for innovation in the use of steel in the manufacturing industry or the economy generally". The recipient is expected to prepare and deliver the Bessemer Lecture.
It was established and endowed to the Iron and Steel Institute in 1874 by Sir Henry Bessemer and was first awarded to Isaac Lowthian Bell in 1874. The Iron and Steel Institute merged in 1974 into the Institute of Metals, which in 1993 became part of the Institute of Materials, which in turn became part of the IOM3 in 2002. | 1 | Applied and Interdisciplinary Chemistry |
In 1903, Ludwig Roselius popularized the use of benzene to decaffeinate coffee. This discovery led to the production of Sanka. This process was later discontinued. Benzene was historically used as a significant component in many consumer products such as liquid wrench, several paint strippers, rubber cements, spot removers, and other products. Manufacture of some of these benzene-containing formulations ceased in about 1950, although Liquid Wrench continued to contain significant amounts of benzene until the late 1970s. | 1 | Applied and Interdisciplinary Chemistry |
Photon energy is transferred to matter in a two-step process. First, energy is transferred to charged particles in the medium through various photon interactions (e.g. photoelectric effect, Compton scattering, pair production, and photodisintegration). Next, these secondary charged particles transfer their energy to the medium through atomic excitation and ionizations.
For low-energy photons, kerma is numerically approximately the same as absorbed dose. For higher-energy photons, kerma is larger than absorbed dose because some highly energetic secondary electrons and X-rays escape the region of interest before depositing their energy. The escaping energy is counted in kerma, but not in absorbed dose. For low-energy X-rays, this is usually a negligible distinction. This can be understood when one looks at the components of kerma.
There are two independent contributions to the total kerma, collision kerma and radiative kerma – thus, . Collision kerma results in the production of electrons that dissipate their energy as ionization and excitation due to the interaction between the charged particle and the atomic electrons. Radiative kerma results in the production of radiative photons due to the interaction between the charged particle and atomic nuclei (mostly via Bremsstrahlung radiation), but can also include photons produced by annihilation of positrons in flight.
Frequently, the quantity is of interest, and is usually expressed as
where g is the average fraction of energy transferred to electrons that is lost through bremsstrahlung. | 0 | Theoretical and Fundamental Chemistry |
Saliva moistens and softens food, and along with the chewing action of the teeth, transforms the food into a smooth bolus. The bolus is further helped by the lubrication provided by the saliva in its passage from the mouth into the esophagus. Also of importance is the presence in saliva of the digestive enzymes amylase and lipase. Amylase starts to work on the starch in carbohydrates, breaking it down into the simple sugars of maltose and dextrose that can be further broken down in the small intestine. Saliva in the mouth can account for 30% of this initial starch digestion. Lipase starts to work on breaking down fats. Lipase is further produced in the pancreas where it is released to continue this digestion of fats. The presence of salivary lipase is of prime importance in young babies whose pancreatic lipase has yet to be developed.
As well as its role in supplying digestive enzymes, saliva has a cleansing action for the teeth and mouth. It also has an immunological role in supplying antibodies to the system, such as immunoglobulin A. This is seen to be key in preventing infections of the salivary glands, importantly that of parotitis.
Saliva also contains a glycoprotein called haptocorrin which is a binding protein to vitamin B. It binds with the vitamin in order to carry it safely through the acidic content of the stomach. When it reaches the duodenum, pancreatic enzymes break down the glycoprotein and free the vitamin which then binds with intrinsic factor. | 1 | Applied and Interdisciplinary Chemistry |
Greenhouse gases exist in many atmospheres, creating greenhouse effects on Mars, Titan and particularly in the thick atmosphere of Venus. While Venus has been described as the ultimate end state of runaway greenhouse effect, such a process would have virtually no chance of occurring from any increases in greenhouse gas concentrations caused by humans, as the Sun's brightness is too low and it would likely need to increase by some tens of percents, which will take a few billion years. | 1 | Applied and Interdisciplinary Chemistry |
PCET is thought to be pervasive. Important examples include water oxidation in photosynthesis, nitrogen fixation, oxygen reduction reaction, and the function of hydrogenases. These processes are relevant to respiration. | 0 | Theoretical and Fundamental Chemistry |
On June 20, 2017, the United States Postal Service released the first application of thermochromic ink to postage stamps in its Total Eclipse of the Sun Forever stamp to commemorate the solar eclipse of August 21, 2017. When pressed with a finger, body heat turns the black circle in the center of the stamp into an image of the full moon. The stamp image is a photo of a total solar eclipse seen in Jalu, Libya, on March 29, 2006. The photo was taken by retired NASA astrophysicist Fred Espenak, aka "Mr. Eclipse". | 0 | Theoretical and Fundamental Chemistry |
G stimulates the membrane-bound phospholipase C beta, which then cleaves PIP (a minor membrane phosphoinositol) into two second messengers, IP3 and diacylglycerol (DAG).
The Inositol Phospholipid Dependent Pathway is used as a signal transduction pathway for many hormones including:
* ADH (Vasopressin/AVP) – Induces the synthesis and release of glucocorticoids (Zona fasciculata of adrenal cortex); Induces vasoconstriction (V1 Cells of Posterior pituitary)
* TRH – Induces the synthesis and release of TSH (Anterior pituitary gland)
* TSH – Induces the synthesis and release of a small amount of T4 (Thyroid Gland)
* Angiotensin II – Induces Aldosterone synthesis and release (zona glomerulosa of adrenal cortex in kidney)
* GnRH – Induces the synthesis and release of FSH and LH (Anterior Pituitary) | 1 | Applied and Interdisciplinary Chemistry |
In 2021, dextrorphan was identified in >75% of sludge samples taken from 12 wastewater treatment plants in California. The same study associated dextrorphan with estrogenic activity by using predictive modelling, before observing it in in vitro. | 0 | Theoretical and Fundamental Chemistry |
Linear expansion means change in one dimension (length) as opposed to change in volume (volumetric expansion).
To a first approximation, the change in length measurements of an object due to thermal expansion is related to temperature change by a coefficient of linear thermal expansion (CLTE). It is the fractional change in length per degree of temperature change. Assuming negligible effect of pressure, one may write:
where is a particular length measurement and is the rate of change of that linear dimension per unit change in temperature.
The change in the linear dimension can be estimated to be:
This estimation works well as long as the linear-expansion coefficient does not change much over the change in temperature , and the fractional change in length is small . If either of these conditions does not hold, the exact differential equation (using ) must be integrated. | 0 | Theoretical and Fundamental Chemistry |
SOCS are negative regulators of the JAK-STAT signaling pathway. SOCS have also been implicated in the regulation of cytokines, growth factors, and tumor suppression. | 1 | Applied and Interdisciplinary Chemistry |
pRb has the ability to reversibly inhibit DNA replication through transcriptional repression of DNA replication factors. pRb is able to bind to transcription factors in the E2F family and thereby inhibit their function. When pRb is chronically activated, it leads to the downregulation of the necessary DNA replication factors. Within 72–96 hours of active pRb induction in A2-4 cells, the target DNA replication factor proteins—MCMs, RPA34, DBF4, RFCp37, and RFCp140—all showed decreased levels. Along with decreased levels, there was a simultaneous and expected inhibition of DNA replication in these cells. This process, however, is reversible. Following induced knockout of pRb, cells treated with cisplatin, a DNA-damaging agent, were able to continue proliferating, without cell cycle arrest, suggesting pRb plays an important role in triggering chronic S-phase arrest in response to genotoxic stress.
One such example of E2F-regulated genes repressed by pRb are cyclin E and cyclin A. Both of these cyclins are able to bind to Cdk2 and facilitate entry into the S phase of the cell cycle. Through the repression of expression of cyclin E and cyclin A, pRb is able to inhibit the G1/S transition. | 1 | Applied and Interdisciplinary Chemistry |
Hattori argued that the prevailing view for volcano formation in arcs ic arc formation, that water is released rapidly from subducting slabs when they are metamorphosed to eclogite facies, is inconsistent with geological evidence. Instead, she proposed an alternative mechanism, suggesting that water is continuously released from slabs and stored as serpentinites (hydrated mantle rocks) and stressed that the subsequent dehydration of these serpentinites triggers the formation of arc volcanoes. Her work has established the importance and distribution of serpentinites on the major ocean floors, which control seismic activity and may potentially have played a role in the origin of life on the planet.
Additionally, Hattori's work highlighted that heavy metals and metalloids, such as arsenic and antimony, are generally considered to be concentrated in sulphides, but under sulphur-deficient conditions, these elements behave like normal rock-forming elements. | 0 | Theoretical and Fundamental Chemistry |
The construction of closed impellers includes additional back and front walls on both sides of vanes that enhances its strength. This also reduces the thrust load on the shaft, increasing bearing life and reliability and reducing shafting cost. However, this more complicated design, including the use of additional wear rings, makes closed impellers more difficult to manufacture and more expensive than open impellers. A closed impellers efficiency decreases as wear ring clearance increases with use. However, adjustment of impeller bowl clearance does not affect the wear on vanes as critically as open impeller. Closed impellers can be used on a wider range specific speed than open impellers. They are generally used in large pumps and clear water applications. These impellers cant perform effectively with solids and become difficult to clean if clogged. | 1 | Applied and Interdisciplinary Chemistry |
Ortho-, pyro-, and tripolyphosphate compounds have been commonly used in detergents (i. e. cleaners) formulations. For example, see Sodium tripolyphosphate. Sometimes pyrophosphate, tripolyphosphate, tetrapolyphosphate, etc. are called diphosphate, triphosphate, tetraphosphate, etc., especially when they are part of phosphate esters in biochemistry. They are also used for scale and corrosion control by potable water providers. As a corrosion inhibitor, polyphosphates work by forming a protective film on the interior surface of pipes. | 0 | Theoretical and Fundamental Chemistry |
Metreleptin is being investigated for the treatment of diabetes and/or hypertriglyceridemia, in patients with rare forms of lipodystrophy, syndromes characterized by abnormalities in adipose tissue distribution, and severe metabolic abnormalities. The FDA approved Metreleptin injection for treating complications of leptin deficiency in February 2014.
In a three-year study of metreleptin in patients with lipodystrophy organized by the National Institute of Diabetes and Digestive and Kidney Diseases at the National Institutes of Health, metreleptin treatment was associated with a significant decrease in blood glucose (A1c decreased from 9.4% at baseline to 7.0% at study end) and triglyceride concentration (from 500 mg/dl at baseline to 200 mg/dl at study end). Metreleptin is effective in most patients with generalized lipodystrophy where circulating leptin levels are extremely low. Analogous to insulin replacement for patients with type 1 Diabetes, metreleptin restores the function of a deficient hormone. However, in patients with partial lipodystrophy where there is only a relative leptin deficiency, the response to metreleptin is not universal. This may or may not be due to anti-leptin antibodies.
NHS England will commission metreleptin treatment for patients (all ages) with congenital leptin deficiency from 1 April 2019.
Metreleptin is undergoing research for its potential benefit in the treatment of anorexia nervosa. It is hypothesized that the gradual loss of body fat mass, and more specifically the ensuing low leptin levels, escalate the preexisting drive for thinness into an obsessive-compulsive-like and addictive-like state. It was shown that short-term metreleptin treatment of patients with anorexia nervosa had rapid on-set of beneficial cognitive, emotional, and behavioral effects. Among other things, depression, drive for activity, repetitive thoughts of food, inner restlessness, and weight phobia decreased rapidly. Whether metreleptin (or another leptin analogue) is a suitable treatment for anorexia nervosa remains to be seen. Potential side effects are weight loss and the development of anti-metreleptin antibodies.
In a clinical study, metreleptin treatment improved non-alcoholic steatohepatitis (fatty liver disease) both in patients with partial lipodystrophy and in those with relative leptin deficiency. Both steatosis and hepatic injury scores decreased. Metreleptin reduces body weight in overweight people with low leptin levels.
Although it is not very effective as a weight loss drug, leptin levels are lowered in people who have lost weight and it is hypothesized that supplemental leptin could help them with weight loss maintenance. However, there is no regulatory pathway for drug approval for this indication. | 1 | Applied and Interdisciplinary Chemistry |
Dielectric constants are not the only measure of polarity. Because solvents are used by chemists to carry out chemical reactions or observe chemical and biological phenomena, more specific measures of polarity are required. Most of these measures are sensitive to chemical structure.
The Grunwald–Winstein mY scale measures polarity in terms of solvent influence on buildup of positive charge of a solute during a chemical reaction.
Kosowers Z scale' measures polarity in terms of the influence of the solvent on UV-absorption maxima of a salt, usually pyridinium iodide or the pyridinium zwitterion.
Donor number and donor acceptor scale measures polarity in terms of how a solvent interacts with specific substances, like a strong Lewis acid or a strong Lewis base.
The Hildebrand parameter is the square root of cohesive energy density. It can be used with nonpolar compounds, but cannot accommodate complex chemistry.
Reichardts dye, a solvatochromic dye that changes color in response to polarity, gives a scale of E(30) values. E is the transition energy between the ground state and the lowest excited state in kcal/mol, and (30) identifies the dye. Another, roughly correlated scale (E'(33)) can be defined with Nile red.
The polarity, dipole moment, polarizability and hydrogen bonding of a solvent determines what type of compounds it is able to dissolve and with what other solvents or liquid compounds it is miscible. Generally, polar solvents dissolve polar compounds best and non-polar solvents dissolve non-polar compounds best; hence "like dissolves like". Strongly polar compounds like sugars (e.g. sucrose) or ionic compounds, like inorganic salts (e.g. table salt) dissolve only in very polar solvents like water, while strongly non-polar compounds like oils or waxes dissolve only in very non-polar organic solvents like hexane. Similarly, water and hexane (or vinegar and vegetable oil) are not miscible with each other and will quickly separate into two layers even after being shaken well.
Polarity can be separated to different contributions. For example, the Kamlet-Taft parameters are dipolarity/polarizability (π*), hydrogen-bonding acidity (α) and hydrogen-bonding basicity (β). These can be calculated from the wavelength shifts of 3–6 different solvatochromic dyes in the solvent, usually including Reichardt's dye, nitroaniline and diethylnitroaniline. Another option, Hansen solubility parameters, separates the cohesive energy density into dispersion, polar, and hydrogen bonding contributions. | 1 | Applied and Interdisciplinary Chemistry |
Magnesium and vitamin D have a synergistic relationship in the body, meaning they work together to optimize each other's functions:
* Magnesium activates vitamin D
* Vitamin D influences magnesium absorption.
* Bone health: They play crucial roles in calcium absorption and bone metabolism.
* Muscle function: They contribute to muscle contraction and relaxation, impacting physical performance and overall well-being.
* Immune function: They support a healthy immune system and may help reduce inflammation.
Overall, maintaining adequate levels of both magnesium and vitamin D is essential for optimal health and well-being. | 1 | Applied and Interdisciplinary Chemistry |
The Strouhal number and Reynolds number must be considered when addressing the ideal method to develop a body made to move through a fluid. Furthermore, the relationship for these values is expressed through Lighthill's elongated-body theory, which relates the reactive forces experienced by a body moving through a fluid with its inertial forces. The Strouhal number was determined to depend upon the dimensionless Lighthill number, which in turn relates to the Reynolds number. The value of the Strouhal number can then be seen to decrease with an increasing Reynolds number, and to increase with an increasing Lighthill number. | 1 | Applied and Interdisciplinary Chemistry |
2,4,6-Triisopropylbenzenesulfonyl azide (trisyl azide) is an organic chemical used as a reagent to supply azide for electrophilic amination reactions, such as for the asymmetric synthesis of unnatural amino acids. Introduction of an azide on the α carbon of carboxylic acid derivative using trisyl azide is an efficient alternative to electrophilic halogenation followed by nucleophilic substitution using anionic azide. Using an oxazolidinone as chiral auxiliary typically gives good induction of the stereochemistry at the α position. Subsequent reduction converts the α-azide to an α-amine. | 0 | Theoretical and Fundamental Chemistry |
SMB provides lower production cost by requiring less column volume, less chromatographic separation media ("packing" or "stationary phase"), using less solvent and less energy, and requiring far less labor.
At industrial scale an SMB chromatographic separator is operated continuously, requiring less resin and less solvent than batch chromatography. The continuous operation facilitates operation control and integration into production plants. | 0 | Theoretical and Fundamental Chemistry |
Pyruvate kinase type M2 or PKM2 is present in embryonic, adult stem cells. It is also expressed by many tumor cells. The alterations to metabolism by PKM2 increases ATP resources, stimulates macromolecular biosynthesis and redox control. Pyruvate kinase catalyses the ATP-generating step of glycolysis in which phosphoenolpyruvate (PEP) is converted to pyruvate. This is a rate-limiting step. It decreases the glycolysis activity and allows carbohydrate metabolites to enter other pathways, like hexosamine pathway, Uridine diphosphate glucose–glucose synthesis, glycerol synthesis and Pentose phosphate pathway or PPP. It helps in generating macromolecule precursors, that are necessary to support cell proliferation, and reducing equivalents such as NADPH. It has been observed in some studies that MYC promotes expression of PKM2 over PKM1 by modulating exon splicing.
A key molecule produced as a result of the oxidative PPP by PKM2 is NADPH. NADPH functions as a cofactor and provides reducing power in many enzymatic reactions that are crucial for macromolecular biosynthesis. Another mechanism by which NADPH is produced in mammalian cells is the reaction converting isocitrate to α-ketoglutarate (αKG), which is catalysed by NADP-dependent isocitrate dehydrogenase 1 (IDH1) and IDH2 and have been found linked to tumorigenesis in glioblastoma and acute myeloid leukemia. They are also found to interact with arginine residues required for isocitrate binding in the active site of the proteins of IDH1 and IDH2. | 1 | Applied and Interdisciplinary Chemistry |
Plant biochemistry encompasses the chemical reactions that occur within plants. In principle, knowledge at a molecular level informs technologies for providing food. Particular focus is on the biochemical differences between plants and other organisms as well as the differences within the plant kingdom, such as dicotyledons vs monocotyledons, gymnosperms vs angiosperms, C2- vs C4-fixers, etc. | 1 | Applied and Interdisciplinary Chemistry |
The transparent window, on to which the sample is deposited, is usually cooled using a compressed helium or similar refrigerant. Experiments must be performed under a high vacuum to prevent contaminants from unwanted gases freezing to the cold window. Lower temperatures are preferred, due to the improved rigidity and "glassiness" of the matrix material. Noble gases such as argon are used not just because of their unreactivity but also because of their broad optical transparency in the solid state. Mono-atomic gases have relatively simple face-centered cubic (fcc) crystal structure, which can make interpretations of the site occupancy and crystal-field splitting of the guest easier. In some cases a reactive material, for example, methane, hydrogen or ammonia, may be used as the host material so that the reaction of the host with the guest species may be studied.
Using the matrix isolation technique, short-lived, highly-reactive species such as radical ions and reaction intermediates may be observed and identified by spectroscopic means. For example, the solid noble gas krypton can be used to form an inert matrix within which a reactive F ion can sit in chemical isolation. The reactive species can either be generated outside (before deposition) the apparatus and then be condensed, inside the matrix (after deposition) by irradiating or heating a precursor, or by bringing together two reactants on the growing matrix surface. For the deposition of two species it can be crucial to control the contact time and temperature. In twin jet deposition the two species have a much shorter contact time (and lower temperature) than in merged jet. With concentric jet the contact time is adjustable. | 0 | Theoretical and Fundamental Chemistry |
A demonstration-scale Fischer–Tropsch plant was built and operated by Rentech, Inc., in partnership with ClearFuels, a company specializing in biomass gasification. Located in Commerce City, Colorado, the facility produces about of fuels from natural gas. Commercial-scale facilities were planned for Rialto, California; Natchez, Mississippi; Port St. Joe, Florida; and White River, Ontario. Rentech closed down their pilot plant in 2013, and abandoned work on their FT process as well as the proposed commercial facilities. | 0 | Theoretical and Fundamental Chemistry |
Such materials include semiconductors that can be photoactivated like many solar cells, biological systems such as those used in photosynthesis, and small molecules with suitable absorptions and redox states. | 0 | Theoretical and Fundamental Chemistry |
Dihydrobiopterin (BH) is a pteridine compound produced in the synthesis of L-DOPA, dopamine, serotonin, norepinephrine and epinephrine. It is restored to the required cofactor tetrahydrobiopterin by dihydrobiopterin reductase. | 1 | Applied and Interdisciplinary Chemistry |
Solid-state processes do not involve melting or evaporating the material and are typically done at relatively low temperatures. Examples of solid state processes include mechanical alloying using a high-energy ball mill and certain types of severe plastic deformation processes. | 1 | Applied and Interdisciplinary Chemistry |
The below list is not exhaustive, but here are some examples of popular cyclic corrosion test standards,
*[https://webstd.volvo.com/webstd/docs/1027,149 ACT 1] (Volvo)
*[https://webstd.volvo.com/webstd/docs/1027,1449 ACT 2] (Volvo)
*CETP 00.00-L-467 (Ford)
*D17 2028 (Renault)
*JASO M 609
*SAE J 2334
*VDA 621-415 | 1 | Applied and Interdisciplinary Chemistry |
Another everyday example of Plateau–Rayleigh instability occurs in urination, particularly standing male urination. The stream of urine experiences instability after about 15 cm (6 inches), breaking into droplets, which causes significant splash-back on impacting a surface. By contrast, if the stream contacts a surface while still in a stable state – such as by urinating directly against a urinal or wall – splash-back is almost completely eliminated. | 1 | Applied and Interdisciplinary Chemistry |
An STR multiplex system is used to identify specific short tandem repeats (STRs). STR polymorphisms are genetic markers that may be used to identify a DNA sequence.
The FBI analyses 13 specific STR loci for their database. These may be used in many areas of genetics in addition to their forensic uses.
One can think of a STR multiplex system as a collection of specific STRs which are positionally conserved on a target genome. Hence these can be used as markers. A number of different STRs along with their loci in a particular genome can be used for genotyping.
For example, the STR multiplex system AmpFlSTR Profiler Plus which analyses nine different STRs (3S1358, vWA, FGA, D8S1179, D21S11, D18S51, D5S818, D13S317, D7S820) plus Amelogenin for sex determination is used for human identification purposes. | 1 | Applied and Interdisciplinary Chemistry |
Industrial processes, such as oil refining, steel making or glass making are major sources of waste heat. | 0 | Theoretical and Fundamental Chemistry |
Biopolymers are natural polymers produced by the cells of living organisms. Like other polymers, biopolymers consist of monomeric units that are covalently bonded in chains to form larger molecules. There are three main classes of biopolymers, classified according to the monomers used and the structure of the biopolymer formed: polynucleotides, polypeptides, and polysaccharides. The Polynucleotides, RNA and DNA, are long polymers of nucleotides. Polypeptides include proteins and shorter polymers of amino acids; some major examples include collagen, actin, and fibrin. Polysaccharides are linear or branched chains of sugar carbohydrates; examples include starch, cellulose, and alginate. Other examples of biopolymers include natural rubbers (polymers of isoprene), suberin and lignin (complex polyphenolic polymers), cutin and cutan (complex polymers of long-chain fatty acids), melanin, and polyhydroxyalkanoates (PHAs).
In addition to their many essential roles in living organisms, biopolymers have applications in many fields including the food industry, manufacturing, packaging, and biomedical engineering. | 1 | Applied and Interdisciplinary Chemistry |
Mackenzie’s family moved to Victoria, British Columbia when he was age 10. He received his Bachelors degree and Masters degree from the University of British Columbia, and began further study at the University of California, Berkeley, in 1937. As a graduate student, Kenneth Ross Mackenzie was involved in the Manhattan Project to help solve how to separate the rare uranium-235 isotope from the identical dominant uranium-238 isotope at Oak Ridge, Tennessee. While working on the Manhattan project, MacKenzie and colleagues borrowed 14,700 tons of silver from the US Treasury and melted it into strands to replace old copper in their magnetic coils. After the war, the silver was melted and returned to the treasury. | 1 | Applied and Interdisciplinary Chemistry |
The anomeric effect is taken into consideration synthetically. Due to its discovery in sugars, sugar and carbohydrate chemistry is one of the more common synthetic uses of the anomeric effect. For instance, the Koenigs-Knorr glycosidation installs an α-OR or β-OR group in high diastereoselectivity which is effected by the anomeric effect. Sophorolipid lactone, (+)-Lepicidin A, and (−)-Lithospermoside are a few of the products synthesized via the Koenigs-Knorr Glycosidation overcoming the anomeric effect. | 0 | Theoretical and Fundamental Chemistry |
CDI can be prepared straightforwardly by the reaction of phosgene with four equivalents of imidazole under anhydrous conditions. Removal of the side product, imidazolium chloride, and solvent results in the crystalline product in ~90% yield.
:4 CHN + C(O)Cl → (CHN)CO + 2 [CHNH]Cl
In this conversion, the imidazole serves both as the nucleophile and the base. An alternative precursor 1-(trimethylsilyl)imidazole requires more preparative effort with the advantage that the coproduct trimethylsilyl chloride is volatile.
CDI hydrolyzes readily to give back imidazole:
:(CHN)CO + HO → 2 CHN + CO
The purity of CDI can be determined by the amount of CO that is formed upon hydrolysis. | 0 | Theoretical and Fundamental Chemistry |
The Herriott cell first appeared in 1965 when Donald R. Herriott and Harry J. Schulte published Folded Optical Delay Lines while at Bell Laboratories. The Herriott cell is made up of two opposing spherical mirrors. A hole is machined into one of the mirrors to allow the input and output beams to enter and exit the cavity. Alternatively, the beam may exit through a hole in the opposite mirror. In this fashion the Herriott cell can support multiple light sources by providing multiple entrance and exit holes in either of the mirrors. Unlike the White cell, the number of traversals is controlled by adjusting the separation distance D between the two mirrors. This cell is also commonly used and has some advantages over the White cell:
* It is simpler than the White cell with only two mirrors that are easier to position and less susceptible to mechanical disturbance of the cell
* Can be more stable than the White cell
However, the Herriot cell does not accept high numerical aperture beams. In addition, larger sized mirrors must be used when longer path lengths are needed. | 0 | Theoretical and Fundamental Chemistry |
The natural ventilation flow rate for buoyancy-driven natural ventilation with vents at two different heights can be estimated with this equation:
:English units:
:SI units: | 1 | Applied and Interdisciplinary Chemistry |
In inorganic chemistry, metal–metal bonds describe attractive interactions between metal centers. The simplest examples are found in bimetallic complexes. Metal–metal bonds can be "supported", i.e. be accompanied by one or more bridging ligands, or "unsupported". They can also vary according to bond order. The topic of metal–metal bonding is usually discussed within the framework of coordination chemistry, but the topic is related to extended metallic bonding, which describes interactions between metals in extended solids such as bulk metals and metal subhalides. | 0 | Theoretical and Fundamental Chemistry |
Sigma non-innocence is a special form of non-innocence, an oxidation characteristic in metal complexes. It is mainly discussed in coordination complexes of late transition metals in their high formal oxidation states. Complexes exhibiting sigma non-innocence differ from classical Werner coordination complexes in that their bonding and antibonding orbitals have an inverted distribution of metal and ligand character (c.f. inverted ligand field). The oxidation of the ligand and a lowered charge at the metal center renders the assignment of the oxidation state non-trivial. | 0 | Theoretical and Fundamental Chemistry |
Polyaniline nanofibers have been shown to be incredibly successful as chemical sensors, as they perform better than conventional polyaniline films in numerous tests. This performance difference has been attributed to their high surface area, porosity, and small diameters which enhance diffusion of materials through the nanofibers. Polyaniline nanofiber sensors function through a change in resistance. The polyaniline nanofiber film is placed on an electrode, where a current flows through. The resistance of the electrode changes when the target interacts with the film, which allows the target to be detected.
One study proposes the creation of hydrogen gas sensors using polyaniline nanofibers. It shows that both doped and dedoped polyaniline nanofibers can be used for detection of hydrogen gas through resistance changes, but the dedoped nanofibers were more stable and had better reproducibility.
Another study shows the potential of polyaniline nanofibers as NO gas sensors. NO gas acts as a strong oxidizing agent to the emeraldine form of polyaniline nanofibers, which causes resistance changes greater than three orders of magnitude at 100 ppm.
Sensing targets can be expanded through adding materials to the polyaniline nanofibers. One study proposes polyaniline nanofiber composites with metal salts for the detection of hydrogen sulfide. Hydrogen sulfide is a weak acid that is dangerous at low ppm, but polyaniline nanofibers can only give a robust response to strong acids. Metal salts can react with hydrogen sulfate to form a metal sulfide precipitate and a strong acid. By combining metal salts and polyaniline nanofibers, detection of hydrogen sulfide can be performed.
Another study decorated polyaniline nanofibers with gold nanoparticles to detect volatile sulfur compounds in expired human breath. These sensors can potentially be used in various breath analyses and also in disease diagnosis for diseases with malodor biomarker gases.
Humidity sensors have also been prepared using polyaniline nanofibers. These sensors were prepared through electrospinning of a N,N-dimethylformamide solution of polyaniline nanofibers, poly(vinyl butyral) (PVB), and poly(ethylene oxide) (PEO). These sensors were shown to have high sensitivity, with resistance changes of three orders of magnitude. Furthermore, the sensors showed good sensing linearity, fast response, small hysterics, and good repeatability. | 0 | Theoretical and Fundamental Chemistry |
White etching cracks (WECs), first reported in 1996, are cracks that can form in the microstructure of bearing steel, leading to the development of a network of branched white cracks. They are usually observed in bearings that have failed due to rolling contact fatigue or accelerated rolling contact fatigue. These cracks can significantly shorten the reliability and operating life of bearings, both in the wind power industry and in several industrial applications.
The exact cause of WECs and their significance in rolling bearing failures have been the subject of much research and discussion. Ultimately, the formation of WECs appears to be influenced by a complex interplay between material, mechanical, and chemical factors, including hydrogen embrittlement, high stresses from sliding contact, inclusions, electrical currents, and temperature. They all also have all been identified as potential drivers of WECs. | 1 | Applied and Interdisciplinary Chemistry |
During a normal Space Shuttle launch, for example, max value of 0.32 atmospheres occurred at an altitude of approximately , about one minute after launch. The three Space Shuttle Main Engines were throttled back to about 65–72% of their rated thrust (depending on payload) as the dynamic pressure approached max ; combined with the propellant grain design of the solid rocket boosters, which reduced the thrust at max by one third after 50 seconds of burn, the total stresses on the vehicle were kept to a safe level.
During a typical Apollo mission, the max (also just over 0.3 atmospheres) occurred between of altitude; approximately the same values occur for the SpaceX Falcon 9.
The point of max is a key milestone during a space vehicle launch, as it is the point at which the airframe undergoes maximum mechanical stress. | 1 | Applied and Interdisciplinary Chemistry |
In ecology, base-richness is the level of chemical bases in water or soil, such as calcium or magnesium ions. Many organisms<nowiki/> prefer base-rich environments. Chemical bases are alkalis, hence base-rich environments are either neutral or alkaline. Because acid-rich environments have few bases, they are dominated by environmental acids (usually organic acids). However, the relationship between base-richness and acidity is not a rigid one – changes in the levels of acids (such as dissolved carbon dioxide) may significantly change acidity without affecting base-richness.
Base-rich terrestrial environments are characteristic of areas where underlying rocks (below soil) are limestone. Seawater is also base-rich, so maritime and marine environments are themselves base-rich.
Base-poor environments are characteristic of areas where underlying rocks (below soil) are sandstone or granite, or where the water is derived directly from rainfall (ombrotrophic). | 0 | Theoretical and Fundamental Chemistry |
Each of the components of the bioretention area is designed to perform a specific function. The grass buffer strip reduces incoming runoff velocity and filters particulates from the runoff. The sand bed also reduces the velocity, filters particulates, and spreads flow over the length of the bioretention area. Aeration and drainage of the planting soil are provided by the deep sand bed. The ponding area provides a temporary storage location for runoff prior to its evaporation or infiltration. Some particulates not filtered out by the grass filter strip or the sand bed settle within the ponding area.
The organic or mulch layer also filters pollutants and provides an environment conducive to the growth of microorganisms, which degrade petroleum-based products and other organic material. This layer acts in a similar way to the leaf litter in a forest and prevents the erosion and drying of underlying soils. Planted groundcover reduces the potential for erosion as well, slightly more effectively than mulch. The maximum sheet flow velocity prior to erosive conditions is 0.3 meters per second (1 foot per second) for planted groundcover and 0.9 meters per second (3 feet per second) for mulch.
The clay in the planting soil provides adsorption sites for hydrocarbons, heavy metals, nutrients and other pollutants. Stormwater storage is also provided by the voids in the planting soil. The stored water and nutrients in the water and soil are then available to the plants for uptake. The layout of the bioretention area is determined after site constraints such as location of utilities, underlying soils, existing vegetation, and drainage are considered. Sites with loamy sand soils are especially appropriate for bioretention because the excavated soil can be backfilled and used as the planting soil, thus eliminating the cost of importing planting soil. An unstable surrounding soil stratum and soils with a clay content greater than 25 percent may preclude the use of bioretention, as would a site with slopes greater than 20 percent or a site with mature trees that would be removed during construction of the best management practices. | 1 | Applied and Interdisciplinary Chemistry |
The law of heat conduction, also known as Fourier's law, states that the rate of heat transfer through a material is proportional to the negative gradient in the temperature and to the area, at right angles to that gradient, through which the heat flows. We can state this law in two equivalent forms: the integral form, in which we look at the amount of energy flowing into or out of a body as a whole, and the differential form, in which we look at the flow rates or fluxes of energy locally.
Newtons law of cooling is a discrete analogue of Fouriers law, while Ohms law is the electrical analogue of Fouriers law and Fick's laws of diffusion is its chemical analogue. | 1 | Applied and Interdisciplinary Chemistry |
An uncoupling protein (UCP) is a mitochondrial inner membrane protein that is a regulated proton channel or transporter. An uncoupling protein is thus capable of dissipating the proton gradient generated by NADH-powered pumping of protons from the mitochondrial matrix to the mitochondrial intermembrane space. The energy lost in dissipating the proton gradient via UCPs is not used to do biochemical work. Instead, heat is generated. This is what links UCP to thermogenesis. However, not every type of UCPs are related to thermogenesis. Although UCP2 and UCP3 are closely related to UCP1, UCP2 and UCP3 do not affect thermoregulatory abilities of vertebrates. UCPs are positioned in the same membrane as the ATP synthase, which is also a proton channel. The two proteins thus work in parallel with one generating heat and the other generating ATP from ADP and inorganic phosphate, the last step in oxidative phosphorylation. Mitochondria respiration is coupled to ATP synthesis (ADP phosphorylation), but is regulated by UCPs. UCPs belong to the mitochondrial carrier (SLC25) family.
Uncoupling proteins play a role in normal physiology, as in cold exposure or hibernation, because the energy is used to generate heat (see thermogenesis) instead of producing ATP. Some plants species use the heat generated by uncoupling proteins for special purposes. Eastern skunk cabbage, for example, keeps the temperature of its spikes as much as 20 °C higher than the environment, spreading odor and attracting insects that fertilize the flowers. However, other substances, such as 2,4-dinitrophenol and carbonyl cyanide m-chlorophenyl hydrazone, also serve the same uncoupling function. Salicylic acid is also an uncoupling agent (chiefly in plants) and will decrease production of ATP and increase body temperature if taken in extreme excess. Uncoupling proteins are increased by thyroid hormone, norepinephrine, epinephrine, and leptin. | 1 | Applied and Interdisciplinary Chemistry |
Dicloxacillin is contraindicated in those with a previous history of allergy (hypersensitivity/anaphylactic reaction) to any penicillins. | 0 | Theoretical and Fundamental Chemistry |
While there is no enrichment of S between trophic levels, the stable isotope can be useful in distinguishing benthic vs. pelagic producers and marsh vs. phytoplankton producers. Similar to C, it can also help distinguish between different phytoplankton as the key primary producers in food webs. The differences between seawater sulfates and sulfides (c. 21‰ vs -10‰) aid scientists in the discriminations. Sulfur tends to be more plentiful in less aerobic areas, such as benthic systems and marsh plants, than the pelagic and more aerobic systems. Thus, in the benthic systems, there are smaller δS values. | 0 | Theoretical and Fundamental Chemistry |
Replikins are a group of peptides, whose increase in concentration in virus or other organism proteins is associated with rapid replication. It is often measured in number of replikins per 100 amino acids. This particular group of peptides have been found to play a significant role in predicting both infectivity and lethality of various viral strains. In particular, this group allowed the prediction of the A/H1N1 pandemic almost one year before onset.
A method for identifying replikins was patented by Samuel and Elenore S. Bogoch in 2001. The peptide group was first identified by a proprietary company called Replikins, who have trademarked the name "Replikin Count". | 1 | Applied and Interdisciplinary Chemistry |
HeAR is expressed by Halorubrum ejinorense. The organism was first isolated from Lake Ejinor in Inner Mongolia, China. | 0 | Theoretical and Fundamental Chemistry |
When ethanol is present, PLD substitutes ethanol for water and covalently attaching the alcohol as the head group of the phospholipid; hence the name phosphatidylethanol. Normally PLD incorporates water to generate phosphatidic acid (PA); the process is termed transphosphatidylation. PLD continues to generate PA in the presence of ethanol and while PEth is generated and the effects of ethanol transphosphatidlyation are through the generation of the unnatural lipid not depletion of PA. | 1 | Applied and Interdisciplinary Chemistry |
The project was announced in 2014. The name and design were inspired by the fictional arc reactor built by Tony Stark, who attended MIT in the comic books.
The concept was born as "a project undertaken by a group of MIT students in a fusion design course. The ARC design was intended to show the capabilities of the new magnet technology by developing a point design for a plant producing as much fusion power as ITER at the smallest possible size. The result was a machine about half the linear dimension of ITER, running at 9 tesla and producing more than 500 megawatt (MW) of fusion power. The students also looked at technologies that would allow such a device to operate in steady state and produce more than of electricity." | 0 | Theoretical and Fundamental Chemistry |
As the name suggests, hepatocyte nuclear factors are expressed predominantly in the liver. However HNFs are also expressed and play important roles in a number of other tissues so that the name hepatocyte nuclear factor is somewhat misleading. Nevertheless, the liver is the only tissue in which a significant number of different HNFs are expressed at the same time. In addition, there are a number of genes which contain multiple promoter and enhancer regions each regulated by a different HNF. Furthermore, efficient expression of these genes require synergistic activation by multiple HNFs. Hence hepatocyte nuclear factors function to ensure liver specific expression of certain genes.
As is the case with many transcription factors, HNFs regulate the expression of a wide variety of target genes and therefore functions. These functions (and especially functions involving the liver) include development and metabolic homeostasis of the organism. For example, HNFs influence expression of the insulin gene as well as genes involved in glucose transport and metabolism. In embryo development, HNF4α is thought to have an important role in the development of the liver, kidney, and intestines. | 1 | Applied and Interdisciplinary Chemistry |
The diffuse series is a series of spectral lines in the atomic emission spectrum caused when electrons jump between the lowest p orbital and d orbitals of an atom. The total orbital angular momentum changes between 1 and 2. The spectral lines include some in the visible light, and may extend into ultraviolet or near infrared. The lines get closer and closer together as the frequency increases never exceeding the series limit. The diffuse series was important in the development of the understanding of electron shells and subshells in atoms. The diffuse series has given the letter d to the d atomic orbital or subshell.
The diffuse series has values given by
The series is caused by transitions from the lowest P state to higher energy D orbitals.
One terminology to identify the lines is: 1P-mD But note that 1P just means the lowest P state in the valence shell of an atom and that the modern designation would start at 2P, and is larger for higher atomic numbered atoms.
The terms can have different designations, mD for single line systems, mδ for doublets and md for triplets.
Since the Electron in the D subshell state is not the lowest energy level for the alkali atom (the S is) the diffuse series will not show up as absorption in a cool gas, however it shows up as emission lines.
The Rydberg correction is largest for the S term as the electron penetrates the inner core of electrons more.
The limit for the series corresponds to electron emission, where the electron has so much energy it escapes the atom.
In alkali metals the P terms are split and . This causes the spectral lines to be doublets, with a constant spacing between the two parts of the double line.
This splitting is called fine structure. The splitting is larger for atoms with higher atomic number. The splitting decreases towards the series limit. Another splitting occurs on the redder line of the doublet. This is because of splitting in the D level and . Splitting in the D level has a lesser amount than the P level, and it reduces as the series limit is approached. | 0 | Theoretical and Fundamental Chemistry |
Surface modification makes paper hydrophobic and oleophilic. This combination allows ink oil to penetrate the paper, but prevents dampening water absorption, which increases papers printability.
Three different plasma-solid interactions are used: etching/ablation, plasma activation, and plasma coating. Etching or ablation is when material is removed from the surface of the solid. Plasma activation is where species in the plasma like ions, electrons, or radicals are used to chemically or physically modify the surface. Lastly, plasma coating is where material is coated to the surface in the form of a thin film. Plasma coating can be used to add hydrocarbons to surfaces which can make a surface non-polar or hydrophobic. The specific type of plasma coating used to add hydrocarbons is called plasma enhanced chemical vapor deposition process or PCVD. | 0 | Theoretical and Fundamental Chemistry |
Diphoterine solution contains an amphoteric, chelating molecule: a substance which is capable of reacting with both acids and alkalis when applied to either type of chemical spill, stopping the aggressive action of a corrosive or irritant chemical, halting the reaction with the body.
However, it is not fully effective at halting the body's reaction with hydrofluoric acid. This is because hydrofluoric acid is poisonous as well as corrosive. Treatment with either Hexafluorine or calcium gluconate is required to deal with hydrofluoric acid contamination.
Like all of the emergency treatments, Diphoterine solution is not a substitute for professional medical attention, so immediate attention from emergency medical personnel should always be sought, especially if the chemical spill was to the eye. | 0 | Theoretical and Fundamental Chemistry |
Non-classical congenital adrenal hyperplasia caused by 21-hydroxylase deficiency (NCCAH) is a milder and late-onset congenital adrenal hyperplasia. Its prevalence rate in different ethnic groups varies from 1 in to 1 in . Some people affected by the condition have no relevant signs and symptoms, while others experience symptoms of hyperandrogenism.
Women with NCCAH usually have normal female genitalia at birth. In later life, the signs and symptoms of the condition may include acne, hirsutism, male-pattern baldness, irregular menstruation, and infertility.
Fewer studies have been published about males with NCCAH comparing to those about females, because males are generally asymptomatic. Males, however, may present with acne and early balding.
While symptoms are usually diagnosed after puberty, children may present with premature adrenarche. | 1 | Applied and Interdisciplinary Chemistry |
In crystallography, a fractional coordinate system (crystal coordinate system) is a coordinate system in which basis vectors used to the describe the space are the lattice vectors of a crystal (periodic) pattern. The selection of an origin and a basis define a unit cell, a parallelotope (i.e., generalization of a parallelogram (2D) or parallelepiped (3D) in higher dimensions) defined by the lattice basis vectors where is the dimension of the space. These basis vectors are described by lattice parameters (lattice constants) consisting of the lengths of the lattice basis vectors and the angles between them .
Most cases in crystallography involve two- or three-dimensional space. In the three-dimensional case, the basis vectors are commonly displayed as with their lengths denoted by respectively, and the angles denoted by , where conventionally, is the angle between and , is the angle between and , and is the angle between and . | 0 | Theoretical and Fundamental Chemistry |
Germann was born in Peru, Miami County, Indiana, the second child of Mary Fredericke Mueller (1864–1942) and Gustave Adolph Germann (1860–1940). His only sibling was Albert Fredrick Ottomar Germann (1886–1976), who was also a physical chemist. Frank Germann graduated from Peru High School in 1906. He received the A.B. in physics from Indiana University in 1911. He received the Sc.D. degree (docteur ès sciences physiques) from the University of Geneva (Geneva, Switzerland) in 1914 with research under the guidance of Philippe-Auguste Guye (1862–1922). | 0 | Theoretical and Fundamental Chemistry |
* O. K. Berdiev
* I. N. Khlopin
* Boris Kuftin
* Gorislava Nikolaevna Lisit︠s︡yna
* Mikhail Evgenievich Masson
* Vadim Mikhailovich Masson
* G. E. Markov
* Alexey Okladnikov
* Viktor Sarianidi | 1 | Applied and Interdisciplinary Chemistry |
Biomass energy can be produced from combustion of waste green material to heat water into steam and drive a steam turbine. Bioenergy can also be processed through a range of temperatures and pressures in gasification, pyrolysis or torrefaction reactions. Depending on the desired end product, these reactions create more energy-dense products (syngas, wood pellets, biocoal) that can then be fed into an accompanying engine to produce electricity at a much lower emission rate when compared with open burning. | 1 | Applied and Interdisciplinary Chemistry |
One classical bioassay is the Ames test. A strain of Salmonella that requires histidine to grow is put on two plates with growth medium containing minimal amounts of histidine and some rat liver extract (to mimick liver metabolism). A suspected mutagen is added to one plate. If the plate with the suspected mutagen grows more visible colonies, it is probably mutagenic: a mutagen might cause the strain of bacterium to regain the ability to make its own histidine.
Most other forms of toxicology testing are also bioassays. Animals or cell cultures may be put under a number of levels of a suspected toxin to ascertain whether the substance causes harmful changes and at what level it does so. The value, a common measure of acute toxicity, describes the dose at which a substance is lethal to 50% of tested animals.
The potency of a drug may be measured using a bioassay. | 1 | Applied and Interdisciplinary Chemistry |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.