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A meta-analysis reported that vitamin D supplementation significantly reduced the risk of type 2 diabetes for non-obese people with prediabetes. Another meta-analysis reported that vitamin D supplementation significantly improved glycemic control [homeostatic model assessment-insulin resistance (HOMA-IR)], hemoglobin A1C (HbA1C), and fasting blood glucose (FBG) in individuals with type 2 diabetes. In prospective studies, high versus low level of vitamin D was respectively associated with significant decrease in risk of type 2 diabetes, combined type 2 diabetes and prediabetes, and prediabetes. A 2011 Cochrane systematic review examined one study that showed vitamin D together with insulin maintained levels of fasting C-peptide after 12 months better than insulin alone. However, it is important to highlight that the studies available to be included in this review presented considerable flaws in quality and design. | 1 | Applied and Interdisciplinary Chemistry |
GLD-2 primarily stabilizes mRNAs that are translationally repressed as well as it strongly promotes bulk polyadenylation. Surprisingly, those functions seem to have little impact on dynamizing efficient target mRNA translation, as it is an efficient Poly(A) Polymerase which helps developing polyadenylation activity. This activity is stimulated by its interaction with a putative RNA-binding protein: GLD-3. It is proposed by some studies that GLD-3 stimulates GLD-2 by recruiting it to the RNA. If so, then bringing GLD-2 to the RNA by other means also should stimulate its activity. | 1 | Applied and Interdisciplinary Chemistry |
Two of the drugs three components were originally developed at the Public Health Agency of Canadas National Microbiology Laboratory (NML), and a third at the U.S. Army Medical Research Institute of Infectious Diseases; the cocktail was optimized by Gary Kobinger, then branch chief of the NML, and is undergoing further development by Leaf Biopharmaceutical (LeafBio, Inc.), a San Diego-based arm of Mapp Biopharmaceutical. LeafBio created ZMapp in collaboration with its parent and Defyrus Inc., each of which had licensed its own cocktail of antibodies, called MB-003 and ZMab. | 1 | Applied and Interdisciplinary Chemistry |
Some are generated from the reaction of low-valence metal complexes with azides:
:LM + NR → LMNR + N
A few imido complexes have been generated by the alkylation of metal nitride complexes:
:LMN + RX → LMNR + X | 0 | Theoretical and Fundamental Chemistry |
Batch reactors are reactors in which the reactants are put in the reactor at time 0 and react until the reaction is stopped. Consequently, the space time is the same as the average residence time in a batch reactor. | 0 | Theoretical and Fundamental Chemistry |
In molecular biology, a scissile bond is a covalent chemical bond that can be broken by an enzyme. Examples would be the cleaved bond in the self-cleaving hammerhead ribozyme or the peptide bond of a substrate cleaved by a peptidase. | 1 | Applied and Interdisciplinary Chemistry |
Prolonged exposure to pyridine may result in liver, heart and kidney damage. Evaluations as a possible carcinogenic agent showed that there is inadequate evidence in humans for the carcinogenicity of pyridine, although there is sufficient evidence in experimental animals. Therefore, IARC considers pyridine as possibly carcinogenic to humans (Group 2B). | 0 | Theoretical and Fundamental Chemistry |
As with synthetic kinetic resolution procedures, enzymatic acylation kinetic resolutions have seen the broadest application in a synthetic context. Especially important has been the use of enzymatic kinetic resolution to efficiently and cheaply prepare amino acids. On a commercial scale, Degussa's methodology employing acylases is capable of resolving numerous natural and unnatural amino acids. The racemic mixtures can be prepared via Strecker synthesis, and the use of either porcine kidney acylase (for straight chain substrates) or an enzyme from the mold Aspergillus oryzae (for branched side chain substrates) can effectively yield enantioenriched amino acids in high (85-90%) yields. The unreacted starting material can be racemized in situ, thus making this a dynamic kinetic resolution.
In addition, lipases are used extensively for kinetic resolution in both academic and industrial settings.
Lipases have been used to resolve primary alcohols, secondary alcohols, a limited number of tertiary alcohols, carboxylic acids, diols, and even chiral allenes. Lipase from Pseudomonas cepacia (PSL) is the most widely used in the resolution of primary alcohols and has been used with vinyl acetate as an acylating agent to kinetically resolve the primary alcohols shown below.
For the resolution of secondary alcohols, pseudomonas cepecia lipase (PSL-C) has been employed effectively to generate excellent ees of the (R')-enantiomer of the alcohol. The use of isopropenyl acetate as the acylating agent results in acetone as the byproduct, which is effectively removed from the reaction using molecular sieves. | 0 | Theoretical and Fundamental Chemistry |
The volume of distribution of levetiracetam is similar to total body water. Levetiracetam modestly binds to plasma proteins (less than 10%). | 0 | Theoretical and Fundamental Chemistry |
Ct analysis, a technique based on the principles of DNA reassociation kinetics, is a biochemical technique that measures how much repetitive DNA is in a DNA sample such as a genome. It is used to study genome structure and organization and has also been used to simplify the sequencing of genomes that contain large amounts of repetitive sequence. | 1 | Applied and Interdisciplinary Chemistry |
Evolution of proteins is slower than DNA since only nonsynonymous mutations in DNA can result in amino acid replacements. Most mutations are neutral to maintain protein function and structure. Therefore, the more similar amino acids are, the more probable that they will be replaced. Conservative replacements are more common than radical replacements, since they can result in less important phenotypic changes. On the other hand, beneficial mutations, enhancing protein functions are most likely to be radical replacements. Also, the physicochemical distances, which are based on amino acids properties, are negatively correlated with probability of amino acids substitutions. Smaller distance between amino acids indicates that they are more likely to undergo replacement. | 1 | Applied and Interdisciplinary Chemistry |
After Masri came back from Washington DC to Palestine in Mid-1990s to establish himself in his home country, he started by founding Palestinians daily newspaper "Al-Ayyam Newspaper (/Arabic: جريدة الأيام/)" and was its publisher. Al Ayyam is today the second largest newspaper in Palestine. | 1 | Applied and Interdisciplinary Chemistry |
During the formation of neutron stars, or in radioactive isotopes capable of electron capture, neutrons are created by electron capture:
This is similar to the inverse beta reaction in that a proton is changed to a neutron, but is induced by the capture of an electron instead of an antineutrino. | 0 | Theoretical and Fundamental Chemistry |
Operando UV-vis spectroscopy is particularly useful for many homogeneous catalytic reactions because organometallic species are often colored. Fiber-optical sensors allow monitoring of the consumption of reactants and production of product within the solution through absorption spectra. Gas consumption as well as pH and electrical conductivity can also be measured using fiber-optic sensors within an operando apparatus. | 0 | Theoretical and Fundamental Chemistry |
Apart from uses in coatings and adhesives they are also used to enhance the performance of polyester tire cord. Other uses include Powder coatings, Coil Coatings, Cationic Electrocoating and primers. Blocked isocyanates have also been used in tertiary oilfield recovery techniques. A blocked isocyanate is pumped into the rock/geological formation and then an organic compound with an active hydrogen is also pumped down. The result is a polymeric gel assisting with oil recovery. The use of sodium bisulfite as a blocking agent has also allowed them to be used in waterborne resins such as PUDs. Similarly, vanillin maybe used as an isocyanate blocker and is actively being researched. It is then used in single component waterborne coatings. | 0 | Theoretical and Fundamental Chemistry |
Bulky ligands are used to control the steric properties of a metal center. They are used for many reasons, both practical and academic. On the practical side, they influence the selectivity of metal catalysts, e.g., in hydroformylation. Of academic interest, bulky ligands stabilize unusual coordination sites, e.g., reactive coligands or low coordination numbers. Often bulky ligands are employed to simulate the steric protection afforded by proteins to metal-containing active sites. Of course excessive steric bulk can prevent the coordination of certain ligands. | 0 | Theoretical and Fundamental Chemistry |
The name is derived from the word kermes as denoting the compound’s red color. The origins of the term is from the French kermès, which is short for alkermès, from the Arabic al-qirmiz a reference to crimson dye made from the bodies of insects (see Kermes (dye)). It was also known as poudre des Chartreux from a story of how it saved the life of a Carthusian monk in 1714. Because of its reputation as a medication and heal-all (or panacea), the formula and production process for Kermes mineral was purchased by the French government in 1720. Used for centuries in medicine as a health treatment, diaphoretic (causing sweat), anti-inflammatory and emetic it was used through the 19th century and its use extended to epilepsy treatment in addition to hectic fever. | 1 | Applied and Interdisciplinary Chemistry |
Typical coatings that can be evaluated with this method are:
*Phosphated (pre-treated) surfaces (with subsequent paint/primer/lacquer/rust preventive)
*Zinc and zinc-alloy plating (see also electroplating). See ISO 4042 for guidance
*Electroplated chromium, nickel, copper, tin
*Coatings not applied electrolytically, such as zinc flake coatings according to ISO 10683
*Organic coatings, such as rust preventives
*Paint Coating
Hot-dip galvanized surfaces are not generally tested in a salt spray test (see ISO 1461 or ISO 10684). Hot-dip galvanizing produces zinc carbonates when exposed to a natural environment, thus protecting the coating metal and reducing the corrosion rate. The zinc carbonates are not produced when a hot-dip galvanized specimen is exposed to a salt spray fog, therefore this testing method does not give an accurate measurement of corrosion protection. ISO 9223 gives the guidelines for proper measurement of corrosion resistance for hot-dip galvanized specimens.
Painted surfaces with an underlying hot-dip galvanized coating can be tested according to this method. See ISO 12944-6.
Testing periods range from a few hours (e.g. 8 or 24 hours of phosphated steel) to more than a month (e.g. 720 hours of zinc-nickel coatings, 1000 hours of certain zinc flake coatings). | 1 | Applied and Interdisciplinary Chemistry |
In early 2004, Novartis Pharmaceuticals have disclosed the detail of a 60g-scale synthesis of (+)-discodermolide. This synthesis utilized the Smith gram-scale approach and the Paterson first-generation endgame. This synthesis allows (+)-discodermolide to be evaluated as an in vivo chemotherapeutic agent for adult patients presenting with advanced solid malignancies in Phase I clinical trials. The Novartis synthesis of (+)-discodermolide has an overall yield of 0.65% with a longest linear sequence of 26 steps and 33 total steps. | 0 | Theoretical and Fundamental Chemistry |
As noted, these number about 251. For a list, see the article list of elements by stability of isotopes. For a complete list noting which of the "stable" 251 nuclides may be in some respect unstable, see list of nuclides and stable nuclide. These questions do not impact the question of whether a nuclide is primordial, since all "nearly stable" nuclides, with half-lives longer than the age of the universe, are also primordial. | 0 | Theoretical and Fundamental Chemistry |
The ocean's alkalinity varies over time, most significantly over geologic timescales (millennia). Changes in the balance between terrestrial weathering and sedimentation of carbonate minerals (for example, as a function of ocean acidification) are the primary long-term drivers of alkalinity in the ocean. Over human timescales, mean ocean alkalinity is relatively stable. Seasonal and annual variability of mean ocean alkalinity is very low.
Alkalinity varies by location depending on evaporation/precipitation, advection of water, biological processes, and geochemical processes.
River dominated mixing also occurs close to the shore; it is strongest close to the mouth of a large river. Here, the rivers can act as either a source or a sink of alkalinity. A follows the outflow of the river and has a linear relationship with salinity.
Oceanic alkalinity also follows general trends based on latitude and depth. It has been shown that A is often inversely proportional to sea surface temperature (SST). Therefore, it generally increases with high latitudes and depths. As a result, upwelling areas (where water from the deep ocean is pushed to the surface) also have higher alkalinity values.
There are many programs to measure, record, and study oceanic alkalinity, together with many of the other characteristics of seawater, like temperature and salinity. These include: GEOSECS (Geochemical Ocean Sections Study), TTO/NAS (Transient Tracers in the Ocean/North Atlantic Study), JGOFS (Joint Global Ocean Flux Study), WOCE (World Ocean Circulation Experiment), CARINA (Carbon dioxide in the Atlantic Ocean). | 0 | Theoretical and Fundamental Chemistry |
Maxwells model was not the first plaster model of a thermodynamic surface: in 1871, even before Gibbs papers, James Thomson had constructed a plaster pressure-volume-temperature plot, based on data for carbon dioxide collected by Thomas Andrews.
Around 1900, the Dutch scientist Heike Kamerlingh Onnes, together with his student Johannes Petrus Kuenen and his assistant Zaalberg van Zelst, continued Maxwell's work by constructing their own plaster thermodynamic surface models. These models were based on accurate experimental data obtained in their laboratory, and were accompanied by specialised tools for drawing the lines of equal pressure. | 0 | Theoretical and Fundamental Chemistry |
* German Chemical Society (GDCh), since 1995
* American Chemical Society (ACS), since 1997
* Royal Society of Chemistry (RSC), since 2011 | 0 | Theoretical and Fundamental Chemistry |
The volume concentration (not to be confused with volume fraction) is defined as the volume of a constituent divided by the volume of the mixture :
Being dimensionless, it is expressed as a number, e.g., 0.18 or 18%; its unit is 1.
There seems to be no standard notation in the English literature.
The letter used here is normative in German literature (see Volumenkonzentration). | 0 | Theoretical and Fundamental Chemistry |
Some crops are grown under the protective shelter of different kinds of plant, whether as wind breaks or for shade. For example, shade-grown coffee, especially Coffea arabica, has traditionally been grown in light shade created by scattered trees with a thin canopy, allowing light through to the coffee bushes but protecting them from overheating. Suitable Asian trees include Erythrina subumbrans (tton tong or dadap), Gliricidia sepium (khae falang), Cassia siamea (khi lek), Melia azedarach (khao dao sang), and Paulownia tomentosa, a useful timber tree. | 1 | Applied and Interdisciplinary Chemistry |
In 1919, he was elected a Fellow of the Royal Society of Edinburgh. His proposers were Alexander Gray, George Alexander Gibson, John Glaister, Diarmid Noel Paton, Ralph Stockman, Thomas Hastie Bryce, Robert Muir, Frederick Orpen Bower and Robert Alexander Houston. He resigned from the Society in 1931.
He retired in 1942 and died in 1949. | 0 | Theoretical and Fundamental Chemistry |
A kaliapparat is a laboratory device invented in 1831 by Justus von Liebig (1803–1873) for the analysis of carbon in organic compounds. The device, made of glass, consists of a series of five bulbs connected and arranged in a triangular shape.
To determine the carbon in an organic compound with a kaliapparat, the substance is first burned, converting any carbon present into carbon dioxide (CO). The gaseous products along with the water vapor produced by combustion are passed through the kaliapparat, which is filled with a potassium hydroxide (KOH) solution. The potassium hydroxide reacts with the CO to trap it as potassium carbonate. The global reaction, ignoring intermediate steps and the corresponding ionic dissociation, can be written as follows:
:2 KOH + CO CO + HO.
Subtracting the mass of the kaliapparat before the combustion from that measured after the combustion gives the amount of CO absorbed. From the mass of CO thus determined, standard stoichiometric calculations then give the mass of carbon in the original sample.
A stylized symbol of a kaliapparat is used in the American Chemical Society logo since 1909, originally designed in the early 20th century by Tiffany's Jewelers. | 0 | Theoretical and Fundamental Chemistry |
Bahadurs publications were ambivalently received, and the overall attention of the scientific community seemed limited since Krishna Bahadur and his co-workers reported that the Jeewanus are alive (a striking statement), the team changed the protocols frequently and documented them somewhat idiosyncratically. Bahadur defined "living units" as "[...] those which grow, multiply, and are metabolically active in a systematic, harmonious, and synchronized manner". Then, NASAs Exobiology Division tasked two biologists in 1967 to review and evaluate the literature so far published by Krishna Bahadur (not to replicate the experiments) on the synthesis and characteristics of the Jeewanu. The two NASA biologists did not debate whether these three criteria are an adequate definition of life, but whether the Jeewanu satisfy these criteria. The NASA report concluded that "the evidence presented on these three points is on the whole unconvincing". The report also stated that the postulated existence of these living units has not been proved and "the nature and properties of the Jeewanu remains to be clarified."
In the 1980s, the Hungarian chemist Tibor Gánti discussed the Jeewanu at length in his chemoton theory—an abstract model of autocatalytic chemical reactions—published first in Hungarian and translated into English in 2003. In the context of self-organizing structures, Gánti considered the Jeewanu a promising model system to understand the origin and fundamentals of life, and one that had never received due attention. In 2011, a German scientist stated that the Jeewanu story pertains to concepts of life, its beginnings, as well as possible artificially created cells.
Experimental duplication work published in 2013 by Gupta and Rai reported that their size varies from 0.5 μ to 3.5 μ in diameter, growth from within, metabolic activities, and "the presence of RNA-like material". The authors stated that the RNA-like material detected in the Jeewanu protocells support the RNA world hypothesis. | 0 | Theoretical and Fundamental Chemistry |
An important concept in thermodynamics is the thermodynamic system, which is a precisely defined region of the universe under study. Everything in the universe except the system is called the surroundings. A system is separated from the remainder of the universe by a boundary which may be a physical or notional, but serve to confine the system to a finite volume. Segments of the boundary are often described as walls; they have respective defined permeabilities. Transfers of energy as work, or as heat, or of matter, between the system and the surroundings, take place through the walls, according to their respective permeabilities.
Matter or energy that pass across the boundary so as to effect a change in the internal energy of the system need to be accounted for in the energy balance equation. The volume contained by the walls can be the region surrounding a single atom resonating energy, such as Max Planck defined in 1900; it can be a body of steam or air in a steam engine, such as Sadi Carnot defined in 1824. The system could also be just one nuclide (i.e. a system of quarks) as hypothesized in quantum thermodynamics. When a looser viewpoint is adopted, and the requirement of thermodynamic equilibrium is dropped, the system can be the body of a tropical cyclone, such as Kerry Emanuel theorized in 1986 in the field of atmospheric thermodynamics, or the event horizon of a black hole.
Boundaries are of four types: fixed, movable, real, and imaginary. For example, in an engine, a fixed boundary means the piston is locked at its position, within which a constant volume process might occur. If the piston is allowed to move that boundary is movable while the cylinder and cylinder head boundaries are fixed. For closed systems, boundaries are real while for open systems boundaries are often imaginary. In the case of a jet engine, a fixed imaginary boundary might be assumed at the intake of the engine, fixed boundaries along the surface of the case and a second fixed imaginary boundary across the exhaust nozzle.
Generally, thermodynamics distinguishes three classes of systems, defined in terms of what is allowed to cross their boundaries:
As time passes in an isolated system, internal differences of pressures, densities, and temperatures tend to even out. A system in which all equalizing processes have gone to completion is said to be in a state of thermodynamic equilibrium.
Once in thermodynamic equilibrium, a system's properties are, by definition, unchanging in time. Systems in equilibrium are much simpler and easier to understand than are systems which are not in equilibrium. Often, when analysing a dynamic thermodynamic process, the simplifying assumption is made that each intermediate state in the process is at equilibrium, producing thermodynamic processes which develop so slowly as to allow each intermediate step to be an equilibrium state and are said to be reversible processes. | 0 | Theoretical and Fundamental Chemistry |
The Johnson–Claisen rearrangement is the reaction of an allylic alcohol with an ortho ester containing a deprotonatable alpha carbon (e.g. triethyl orthoacetate) to give a ester. | 0 | Theoretical and Fundamental Chemistry |
UTP also has the role of a source of energy or an activator of substrates in metabolic reactions, like that of ATP, but more specific. When UTP activates a substrate (like Glucose-1-phosphate), UDP-glucose is formed and inorganic phosphate is released.
UDP-glucose enters the synthesis of glycogen. UTP is used in the metabolism of galactose, where the activated form UDP-galactose is converted to UDP-glucose. UDP-glucuronate is used to conjugate bilirubin to a more water-soluble bilirubin diglucuronide. UTP is also used to activate amino sugars like Glucosamine-1-phosphate to UDP-glucosamine, and N-acetyl-glucosamine-1-phosphate to UDP-N-acetylglucosamine. | 1 | Applied and Interdisciplinary Chemistry |
This section is not concerned with sculpture in bronze, but rather with the many artistic applications of the metal in connection with architecture, or with objects for ecclesiastical and domestic use. Why bronze was preferred in Italy, iron in Spain and Germany and brass in the Low Countries cannot be satisfactorily determined; national temperamente is impressed on the choice of metals and also on the methods of working them. Centres of artistic energy shift from one place to another owing to wars, conquests or migrations. | 1 | Applied and Interdisciplinary Chemistry |
Fluoride () is an inorganic, monatomic anion of fluorine, with the chemical formula (also written ), whose salts are typically white or colorless. Fluoride salts typically have distinctive bitter tastes, and are odorless. Its salts and minerals are important chemical reagents and industrial chemicals, mainly used in the production of hydrogen fluoride for fluorocarbons. Fluoride is classified as a weak base since it only partially associates in solution, but concentrated fluoride is corrosive and can attack the skin.
Fluoride is the simplest fluorine anion. In terms of charge and size, the fluoride ion resembles the hydroxide ion. Fluoride ions occur on Earth in several minerals, particularly fluorite, but are present only in trace quantities in bodies of water in nature. | 1 | Applied and Interdisciplinary Chemistry |
ADVB-PA Award – Association of Sales and Marketing Managers from Brazil: Top Environmental Company Award, 2012. | 1 | Applied and Interdisciplinary Chemistry |
Flat roofs – 1% to 2% slope
Low slope-3:12 to 5:12
Medium Slope-6:12 to 9:12
High Slope-10:12 to 12:12
;Subtropical regions in the US where SCV roofs could apply
Here are some of the states where humid subtropical climates can be found:
* Eastern half of Texas
* Louisiana
* Arkansas
* Alabama
* Mississippi
* North Carolina
* South Carolina
* Tennessee
* Georgia
* Kentucky
* most of Florida
* Virginia
* southern West Virginia
The climate in many of these states can vary and be extreme.
Benefits (Performance ratings)
* Reduces stormwater volume (50%–85%)
* Improves stormwater quality through load reduction
* Saves water by rainwater harvesting
* Reduces heat island effect
* Lowers surface temperatures by 40–50 degrees Fahrenheit
* Energy savings can reach 15%–30%
* Reduces noise for building occupants
* Increases the life of the roof and reduces roof maintenance
* Contributes to biodiversity and creates habitats for birds and invertebrates
* Filters air pollutant particles
* Increased storm event safety
* Neighborhood diversity
* Aesthetic value
* Reduces need for retention ponds and ditches | 1 | Applied and Interdisciplinary Chemistry |
With deep WGS data of cfDNA from a carcinoma of unknown primary patient with very low ctDNA concentration quantified, they trained a machine learning model using bootstrapping. The results of RNA-sequencing on PBMC runs for the 5 different patients are recorded and the average of 3 of these individuals expression levels is used as a reference for gene expression. The genes are clustered into 10 clusters based on reference gene expression to increase the resolution at the core promoters. Then, genes used as a background value for PFE calculation are removed. Next, all the fragments in extended TSS regions, a region that has the center as TSS regions center and the length of 2000 base pairs, are pooled. The PFE and NDR scores are calculated for the fragments pooled. Further normalization of these scores is done based on their 95th percentile.
Using these two features, they bootstrapped, used in a weighted fashion, 600 expression prediction models developed for WGS data. Among those models, there are 200 univariable standalone NDR, 200 univariable standalone PFE, and 200 NDR-PFE integrated models. | 1 | Applied and Interdisciplinary Chemistry |
The compound crystallizes in a tetragonal body-centered unit cell of space group symmetry I4md. In the solid-state diethylzinc shows nearly linear Zn centres. The Zn-C bonds measure 194.8(5) pm, while the C-Zn-C angle is slightly bent with 176.2(4)°. The structure of the gas-phase shows a very similar Zn-C distance (195.0(2) pm). | 0 | Theoretical and Fundamental Chemistry |
When symptoms of the essential tremors are considerably high, non-selective β-blockers are an important treatment option and usually the first choice. Studies have shown that propranolol did reduce symptoms the most in that category. The β-blockers can be used alone or in a combination. | 1 | Applied and Interdisciplinary Chemistry |
Cavendish died at Clapham on 24 February 1810 (as one of the wealthiest men in Britain) and was buried, along with many of his ancestors, in the church that is now Derby Cathedral. The road he used to live on in Derby has been named after him, as has a road near his house in Clapham, of which the north part is part of the South Circular Road. The University of Cambridges Cavendish Laboratory was endowed by one of Cavendishs later relatives, William Cavendish, 7th Duke of Devonshire (Chancellor of the University from 1861 to 1891). | 1 | Applied and Interdisciplinary Chemistry |
Metal sulfides (e.g., pyrite FeS, arsenopyrite FeAsS, chalcopyrite CuFeS) are normally processed by chemical oxidation either in aqueous media or at high temperatures. In fact, most base metals, e.g., aluminium, chromium, must be (electro)chemically reduced at high temperatures by which the process entails a high energy demand, and sometimes large volumes of aqueous waste is generated. In aqueous media chalcopyrite, for instance, is more difficult to dissolve chemically than covellite and chalcocite due to surface effects (formation of polysulfide species,). The presence of Cl ions has been suggested to alter the morphology of any sulfide surface formed, allowing the sulfide mineral to leach more easily by preventing passivation. DESs provide a high Cl ion concentration and low water content, whilst reducing the need for either high additional salt or acid concentrations, circumventing most oxide chemistry. Thus, the electrodissolution of sulfide minerals has demonstrated promising results in DES media in absence of passivation layers, with the release into the solution of metal ions which could be recovered from solution.
During extraction of copper from copper sulfide minerals with Ethaline, chalcocite (CuS) and covellite (CuS) produce a yellow solution, indicating that [CuCl] complex are formed. Meanwhile, in the solution formed from chalcopyrite, Cu and Cu species co-exist in solution due to the generation of reducing Fe species at the cathode. The best selective recovery of copper (>97%) from chalcopyrite can be obtained with a mixed DES of 20 wt.% ChCl-oxalic acid and 80 wt.% Ethaline. | 1 | Applied and Interdisciplinary Chemistry |
To explain the wide range of isotopic compositions observed among the amino acids, it is necessary to consider how isotopes are sorted between starting materials, intermediates, and products in reaction networks. Amino acid biosynthesis pathways contain both reversible and irreversible reactions, as well as branch points where one intermediate can react to form two different products. The following examples adapted from Hayes (2001) illustrate the isotopic consequences of these network structures. | 0 | Theoretical and Fundamental Chemistry |
The use of peptides as drugs has some disadvantages because of their bioavailability and biostability. Rapid degradation, poor oral availability, difficult transportation through cell membranes, nonselective receptor binding, and challenging multistep preparation are the major limitations of peptides as active pharmaceutical ingredients. Therefore, small protein-like chains called peptidomimetics could be designed and used to mimic native analogs and conceivably exhibit better pharmacological properties. Many peptidomimetics are utilized as FDA-approved drugs, such as Romidepsin (Istodax), Atazanavir (Reyataz), Saquinavir (Invirase), Oktreotid (Sandostatin), Lanreotide (Somatuline), Plecanatide (Trulance), Ximelagatran (Exanta), Etelcalcetide (Parsabiv), and Bortezomib (Velcade).
Peptidomimetic approaches have been utilized to design small molecules that selectively target cancer cells, an approach known as targeted chemotherapy, by inducing programmed cell death by a process called apoptosis. The following two examples mimic proteins involved in key Protein–protein interactions that reactivate the apoptotic pathway in cancer but do so by distinct mechanisms.
In 2004, Walensky and co-workers reported a stabilized alpha helical peptide that mimics pro-apoptotic BH3-only proteins, such as BID and BAD. This molecule was designed to stabilize the native helical structure by forming a macrocycle between side chains that are not involved in binding. This process, referred to as peptide stapling, uses non-natural amino acids to facilitate macrocyclization by ring-closing olefin metathesis. In this case, a stapled BH3 helix was identified which specifically activates the mitochondrial apoptotic pathway by antagonizing the sequestration of BH3-only proteins by anti-apoptotic proteins (e.g. Bcl-2, see also intrinsic and extrinsic inducers of the apoptosis). This molecule suppressed growth of human leukemia in a mouse xenograft model.
Also in 2004, Harran and co-workers reported a dimeric small molecule that mimics the proapoptotic protein Smac (see mitochondrial regulation in apoptosis). This molecule mimics the N-terminal linear motif Ala-Val-Pro-Ile. Uniquely, the dimeric structure of this peptidomimetic led to a marked increase in activity over an analogous monomer. This binding cooperativity results from the molecule's ability to also mimic the homodimeric structure of Smac, which is functionally important for reactivating caspases. Smac mimetics of this type can sensitize an array of non-small-cell lung cancer cells to conventional chemotherapeutics (e.g. Gemcitabine, Vinorelbine) both in vitro and in mouse xenograft models.
Heterocycles are often used to mimic the amide bond of peptides. Thiazoles, for example, are found in naturally occurring peptides and used by researchers to mimic the amide bond of peptides. | 0 | Theoretical and Fundamental Chemistry |
The mass of the atoms forming a chemical bond affects the bond’s strength. When two different isotopes of the same element exist, the heavier ones form stronger bonds. Stronger bonds make bond cleavage reactions run more slowly, leading to the kinetic isotope effect, a well-studied concept in physical chemistry. To illustrate this with an example from soccer, if one of the two identical soccer balls is filled up with air and another one with water, they will look identical on the ground, but a stronger kick would be required to send the water-filled ball the same distance as the air-filled one. Of the two stable isotopes of hydrogen (H), Deuterium (H) is twice as heavy as protium (H), thus giving the largest kinetic isotope effect of all stable (non-radioactive) atoms.
The kinetic isotope effect is sometimes applied in another context in drug development, modulating drug properties in a favorable/patient-friendly way (deuterated drugs). Small molecules used as drugs are recognized as “foreign” to the body, and an organism’s defense systems often mount a response. Typically, drug metabolism alters the drug molecule through oxidation into derivatives that are easier to excrete, reducing the drug’s half-life. This can be slowed down by deuteration, hence improving pharmacokinetics and pharmacodynamics. | 0 | Theoretical and Fundamental Chemistry |
Neptunes moon Triton is observed to have the reddish color characteristic of tholins. Tritons atmosphere is mostly nitrogen, with trace amounts of methane and carbon monoxide. | 0 | Theoretical and Fundamental Chemistry |
McDermott obtained her Bachelor of Science in Chemistry from Harvey Mudd College in Claremont, CA in 1981. In 1988, she obtained her doctoral degree at U.C. Berkeley in the Department of Chemistry with Kenneth Sauer and Melvin Klein. | 0 | Theoretical and Fundamental Chemistry |
In internal combustion engines, exhaust gas recirculation (EGR) is a nitrogen oxide () emissions reduction technique used in petrol/gasoline, diesel engines and some hydrogen engines. EGR works by recirculating a portion of an engine's exhaust gas back to the engine cylinders. The exhaust gas displaces atmospheric air and reduces in the combustion chamber. Reducing the amount of oxygen reduces the amount of fuel that can burn in the cylinder thereby reducing peak in-cylinder temperatures. The actual amount of recirculated exhaust gas varies with the engine operating parameters.
In the combustion cylinder, is produced by high-temperature mixtures of atmospheric nitrogen and oxygen, and this usually occurs at cylinder peak pressure. In a spark-ignition engine, an ancillary benefit of recirculating exhaust gases via an external EGR valve is an increase in efficiency, as charge dilution allows a larger throttle position and reduces associated pumping losses. Mazda's turbocharged SkyActiv gasoline direct injection engine uses recirculated and cooled exhaust gases to reduce combustion chamber temperatures, thereby permitting the engine to run at higher boost levels before the air-fuel mixture must be enriched to prevent engine knocking.
In a gasoline engine, this inert exhaust displaces some amount of combustible charge in the cylinder, effectively reducing the quantity of charge available for combustion without affecting the air-fuel ratio. In a diesel engine, the exhaust gas replaces some of the excess oxygen in the pre-combustion mixture. Because forms primarily when a mixture of nitrogen and oxygen is subjected to high temperature, the lower combustion chamber temperatures caused by EGR reduces the amount of that the combustion process generates. Gases re-introduced from EGR systems will also contain near equilibrium concentrations of and CO; the small fraction initially within the combustion chamber inhibits the total net production of these and other pollutants when sampled on a time average. Chemical properties of different fuels limit how much EGR may be used. For example methanol is more tolerant to EGR than gasoline. | 1 | Applied and Interdisciplinary Chemistry |
In 2007 the New Zealand Society of Plant Biologists renamed their annual award after Slack. The award is made to society members to recognise an outstanding contribution to the study of plant biology. It was renamed in recognition of his outstanding contribution as a plant biologist and biochemist in New Zealand, his role in the discovery of C4 photosynthesis (also known as the Hatch Slack Pathway), and his contribution as an early member of the New Zealand Society of Plant Biologists. | 1 | Applied and Interdisciplinary Chemistry |
The Ray–Dutt twist is a mechanism proposed for the racemization of octahedral complexes containing three bidentate chelate rings. Such complexes typically adopt an octahedral molecular geometry in their ground states, in which case they possess helical chirality. The pathway entails formation of an intermediate of C point group symmetry. An alternative pathway that also does not break any metal-ligand bonds is called the Bailar twist. Both of these mechanism product complexes wherein the ligating atoms (X in the scheme) are arranged in an approximate trigonal prism.
This pathway is called the Ray–Dutt twist in honor of Priyadaranjan Ray (not Prafulla Chandra Ray) and N. K. Dutt, inorganic chemists at the Indian Association for the Cultivation of Science abbr. IACS who proposed this process. | 0 | Theoretical and Fundamental Chemistry |
Plants express the mechanistic target of rapamycin (mTOR) and have a TOR kinase complex. In plants, only the TORC1 complex is present unlike that of mammalian target of rapamycin which also contains the TORC2 complex. Plant species have TOR proteins in the protein kinase and FKBP-rapamycin binding (FRB) domains that share a similar amino acid sequence to mTOR in mammals.
Role of mTOR in plants
The TOR kinase complex has been known for having a role in the metabolism of plants. The TORC1 complex turns on when plants are living the proper environmental conditions to survive. Once activated, plant cells undergo particular anabolic reactions. These include plant development, translation of mRNA and the growth of cells within the plant. However, the TORC1 complex activation stops catabolic processes such as autophagy from occurring. TOR kinase signaling in plants has been found to aid in senescence, flowering, root and leaf growth, embryogenesis, and the meristem activation above the root cap of a plant. mTOR is also found to be highly involved in developing embryo tissue in plants. | 1 | Applied and Interdisciplinary Chemistry |
Fluorescent X-rays are scattered by atoms in a sample and provide the object wave, which is referenced to non-scattered X-rays. A holographic pattern is recorded by scanning a detector around the sample, which allows researchers to investigate the local 3D structure around a specific element in a sample. | 0 | Theoretical and Fundamental Chemistry |
Soon after the first demonstration of hyper Rayleigh scattering optical activity in metal nanoparticles, the effect was replicated in organic molecules, specifically aromatic oligoamide foldamers. | 0 | Theoretical and Fundamental Chemistry |
Eoxin A4, also known as 14,15-leukotriene A4, is an eoxin. Cells make eoxins by metabolizing arachidonic acid with a 15-lipoxygenase enzyme to form 15(S)-hydroperoxyeicosapentaenoic acid (i.e. 15(S)-HpETE). This product is then converted serially to eoxin A4 (i.e. EXA4), EXC4, EXD4, and EXE4 by LTC4 synthase, an unidentified gamma-glutamyltransferase, and an unidentified dipeptidase, respectively, in a pathway which appears similar if not identical to the pathway which forms leukotreines, i.e. LTA4, LTC4, LTD4, and LTE4. This pathway is schematically shown as follows:
EXA is viewed as an intracellular-bound, short-lived intermediate which is rapidly metabolized to the down-stream eoxins. The eoxins down stream of EXA4 are secreted from their parent cells and, it is proposed but not yet proven, serve to regulate allergic responses and the development of certain cancers (see Eoxins). | 1 | Applied and Interdisciplinary Chemistry |
Some naturally occurring isotopes are entirely radiogenic, but all those are radioactive isotopes, with half-lives too short to have occurred primordially and still exist today. Thus, they are only present as radiogenic daughters of either ongoing decay processes, or else cosmogenic (cosmic ray induced) processes that produce them in nature freshly. A few others are naturally produced by nucleogenic processes (natural nuclear reactions of other types, such as neutron absorption).
For radiogenic isotopes that decay slowly enough, or that are stable isotopes, a primordial fraction is always present, since all sufficiently long-lived and stable isotopes do in fact naturally occur primordially. An additional fraction of some of these isotopes may also occur radiogenically.
Lead is perhaps the best example of a partly radiogenic substance, as all four of its stable isotopes (Pb, Pb, Pb, and Pb) are present primordially, in known and fixed ratios. However, Pb is only present primordially, while the other three isotopes may also occur as radiogenic decay products of uranium and thorium. Specifically, Pb is formed from U, Pb from U, and Pb from Th. In rocks that contain uranium and thorium, the excess amounts of the three heavier lead isotopes allows the rocks to be "dated", thus providing a time estimate for when the rock solidified and the mineral held the ratio of isotopes fixed and in place.
Another notable radiogenic nuclide is argon-40, formed from radioactive potassium. Almost all the argon in the Earth's atmosphere is radiogenic, whereas primordial argon is argon-36.
Some nitrogen-14 is radiogenic, coming from the decay of carbon-14 (half-life around 5700 years), but the carbon-14 was formed some time earlier from nitrogen-14 by the action of cosmic rays.
Other important examples of radiogenic elements are radon and helium, both of which form during the decay of heavier elements in bedrock. Radon is entirely radiogenic, since it has too short a half-life to have occurred primordially. Helium, however, occurs in the crust of the Earth primordially, since both helium-3 and helium-4 are stable, and small amounts were trapped in the crust of the Earth as it formed. Helium-3 is almost entirely primordial (a small amount is formed by natural nuclear reactions in the crust). Helium-3 can also be produced as the decay product of tritium (H) which is a product of some nuclear reactions, including ternary fission. The global supply of helium (which occurs in gas wells as well as the atmosphere) is mainly (about 90%–99%) radiogenic, as shown by its factor of 10 to 100 times enrichment in radiogenic helium-4 relative to the primordial ratio of helium-4 to helium-3. This latter ratio is known from extraterrestrial sources, such as some Moon rocks and meteorites, which are relatively free of parental sources for helium-3 and helium-4.
As noted in the case of lead-204, a radiogenic nuclide is often not radioactive. In this case, if its precursor nuclide has a half-life too short to have survived from primordial times, then the parent nuclide will be gone, and known now entirely by a relative excess of its stable daughter. In practice, this occurs for all radionuclides with half lives less than about 50 to 100 million years. Such nuclides are formed in supernovas, but are known as extinct radionuclides, since they are not seen directly on the Earth today.
An example of an extinct radionuclide is iodine-129; it decays to xenon-129, a stable isotope of xenon which appears in excess relative to other xenon isotopes. It is found in meteorites that condensed from the primordial Solar System dust cloud and trapped primordial iodine-129 (half life 15.7 million years) sometime in a relative short period (probably less than 20 million years) between the iodine-129's creation in a supernova, and the formation of the Solar System by condensation of this dust. The trapped iodine-129 now appears as a relative excess of xenon-129. Iodine-129 was the first extinct radionuclide to be inferred, in 1960. Others are aluminium-26 (also inferred from extra magnesium-26 found in meteorites), and iron-60. | 0 | Theoretical and Fundamental Chemistry |
Accurate determination of core temperature often requires a special low temperature thermometer, as most clinical thermometers do not measure accurately below . A low temperature thermometer can be placed in the rectum, esophagus or bladder. Esophageal measurements are the most accurate and are recommended once a person is intubated. Other methods of measurement such as in the mouth, under the arm, or using an infrared ear thermometer are often not accurate.
As a hypothermic person's heart rate may be very slow, prolonged feeling for a pulse could be required before detecting. In 2005, the American Heart Association recommended at least 30–45 seconds to verify the absence of a pulse before initiating CPR. Others recommend a 60-second check.
The classical ECG finding of hypothermia is the Osborn J wave. Also, ventricular fibrillation frequently occurs below and asystole below . The Osborn J may look very similar to those of an acute ST elevation myocardial infarction. Thrombolysis as a reaction to the presence of Osborn J waves is not indicated, as it would only worsen the underlying coagulopathy caused by hypothermia. | 1 | Applied and Interdisciplinary Chemistry |
In 2015 the use of highly porous, catalyst-decorated COFs for converting carbon dioxide into carbon monoxide was reported. MOF under solvent-free conditions can also be used for catalytic activity in the cycloaddition of CO and epoxides into cyclic organic carbonates with enhanced catalyst recyclability. | 0 | Theoretical and Fundamental Chemistry |
The Austrian pharmaceutical company, Biochemie, was founded in Kundl in July 1946 at the site of a derelict brewery, at the suggestion of a French officer, Michel Rambaud (a chemist), who was able to obtain a small amount of Penicillium start culture from France. Contamination of the fermentation tanks was a persistent problem and in 1951, the company biologist, Ernst Brandl, attempted to solve this by adding phenoxyethanol to the tanks as an anti-bacterial disinfectant. This resulted unexpectedly in an increase in penicillin production: but, the penicillin produced was not benzylpenicillin, but phenoxymethylpenicillin. Phenoxyethanol was fermented to phenoxyacetic acid in the tanks, which was then incorporated into penicillin via biosynthesis. Importantly, Brandl realised that phenoxymethylpenicillin is not destroyed by stomach acid and can therefore be given by mouth. Phenoxymethyl penicillin was originally discovered by Eli Lilly in 1948 as part of their efforts to study penicillin precursors, but was not further exploited, and there is no evidence that Lilly understood the significance of their discovery at the time.
Biochemie is part of Sandoz. | 0 | Theoretical and Fundamental Chemistry |
Metal foams are popular support for electrocatalysts due to the high surface area and stable structure. The interconnected pores also benefit the mass transport of reactants and products. However, the benchmark of electrocatalysts can be difficult due to the undetermined surface area, different foam properties, and capillary effect. | 0 | Theoretical and Fundamental Chemistry |
Early diffusion models postulated that atomic motion in substitutional alloys occurs via a direct exchange mechanism, in which atoms migrate by switching positions with atoms on adjacent lattice sites. Such a mechanism implies that the atomic fluxes of two different materials across an interface must be equal, as each atom moving across the interface causes another atom to move across in the other direction.
Another possible diffusion mechanism involves lattice vacancies. An atom can move into a vacant lattice site, effectively causing the atom and the vacancy to switch places. If large-scale diffusion takes place in a material, there will be a flux of atoms in one direction and a flux of vacancies in the other.
The Kirkendall effect arises when two distinct materials are placed next to each other and diffusion is allowed to take place between them. In general, the diffusion coefficients of the two materials in each other are not the same. This is only possible if diffusion occurs by a vacancy mechanism; if the atoms instead diffused by an exchange mechanism, they would cross the interface in pairs, so the diffusion rates would be identical, contrary to observation. By Fick's 1st law of diffusion, the flux of atoms from the material with the higher diffusion coefficient will be larger, so there will be a net flux of atoms from the material with the higher diffusion coefficient into the material with the lower diffusion coefficient. To balance this flux of atoms, there will be a flux of vacancies in the opposite direction—from the material with the lower diffusion coefficient into the material with the higher diffusion coefficient—resulting in an overall translation of the lattice relative to the environment in the direction of the material with the lower diffusion constant.
Macroscopic evidence for the Kirkendall effect can be gathered by placing inert markers at the initial interface between the two materials, such as molybdenum markers at an interface between copper and brass. The diffusion coefficient of zinc is higher than the diffusion coefficient of copper in this case. Since zinc atoms leave the brass at a higher rate than copper atoms enter, the size of the brass region decreases as diffusion progresses. Relative to the molybdenum markers, the copper-brass interface moves toward the brass at an experimentally measurable rate. | 1 | Applied and Interdisciplinary Chemistry |
The output of SAGE is a list of short sequence tags and the number of times it is observed. Using sequence databases a researcher can usually determine, with some confidence, from which original mRNA (and therefore which gene) the tag was extracted.
Statistical methods can be applied to tag and count lists from different samples in order to determine which genes are more highly expressed. For example, a normal tissue sample can be compared against a corresponding tumor to determine which genes tend to be more (or less) active. | 1 | Applied and Interdisciplinary Chemistry |
The sample should be vacuum stable. It is typically mounted using a conductive compound (e.g. an epoxy thermoset filled with Cu), which minimises image drift and sample charging under electron beam irradiation. EBSP quality is sensitive to surface preparation. Typically the sample is ground using SiC papers from 240 down to 4000 grit, and polished using diamond paste (from 9 to 1 µm) then in 50 nm colloidal silica. Afterwards, it is cleaned in ethanol, rinsed with deionised water, and dried with a hot air blower. This may be followed by ion beam polishing, for final surface preparation.
Inside the SEM, the size of the measurement area determines local resolution and measurement time. Usual settings for high-quality EBSPs are 15 nA current, 20 kV beam energy, 18 mm working distance, long exposure time, and minimal CCD pixel binning. The EBSD phosphor screen is set at an 18 mm working distance and a map's step size of less than 0.5 µm for strain and dislocations density analysis.
Decomposition of gaseous hydrocarbons and also hydrocarbons on the surface of samples by the electron beam inside the microscope results in carbon deposition, which degrades the quality of EBSPs inside the probed area compared to the EBSPs outside the acquisition window. The gradient of pattern degradation increases moving inside the probed zone with an apparent accumulation of deposited carbon. The black spots from the beam instant-induced carbon deposition also highlight the immediate deposition even if agglomeration did not happen. | 0 | Theoretical and Fundamental Chemistry |
Dr Mukherjee was able to foresee how basic soil colloid studies could be of help in understanding many of the soil properties and problems. He brought to use in
the study of the soil all the tools and techniques he had been developing and improving through years of patient research. In 1942, with N.C. Sen Gupta, he developed a
simple rotary viscometer for the study of anomalous viscous properties. In 1944, he developed the method of differentiation of crude oils based on chromatography capillary analysis and fluorescence in UV light. | 0 | Theoretical and Fundamental Chemistry |
The 19th century (1800s) birthed "pharmacy as we know it." And again, pharmacy's development in mainland Europe continued to fuel its growth in the young American republic. | 1 | Applied and Interdisciplinary Chemistry |
Water-based defoamers are different types of oils and waxes dispersed in a water base. The oils are often mineral oil or vegetable oils and the waxes are long chain fatty alcohol, fatty acid soaps or esters. These are normally best as deaerators, which means they are best at releasing entrained air. | 0 | Theoretical and Fundamental Chemistry |
In 2006, Pilot Pens Inc. developed a pen with erasable ink that utilized thermochromic ink. It was composed of a solvent, a colorant, and a resin film-forming agent. At temperatures below 65 °C, the ink stayed in a colored state. Once temperatures went above 65 °C, the ink began to melt and became colorless, creating the effect of erasable ink. The ink was able to return to its colored state by cooling the temperature down to below -10 °C. | 0 | Theoretical and Fundamental Chemistry |
The earliest example of a [4+4] photocycloaddition was the photodimerization of anthracene, discovered in 1936. This reaction has remained one of the most reliable photocycloadditions and is the basis of continuing investigation.
Other polycyclic aromatics undergo anthracene-like photocycloaddition, such as acridizinium salts. Biologically active natural products include pleuromutilin, kalmanol, crenulide, and longipenol.
[4+4] photocycloaddition approaches to the creation of cyclooctanoid systems offer several appealing features, including convergent assembly of the eight-membered ring from two relatively simpler four-carbon fragments, formation of two new carbon-carbon bonds, and the potential for introduction of up to four new stereocenters in one step. | 0 | Theoretical and Fundamental Chemistry |
Charles Wood (1702 – October 1774) was an English ironmaster and one of the inventors of the potting and stamping method of making wrought iron from pig iron. | 1 | Applied and Interdisciplinary Chemistry |
In the field of cellular biology, single-cell analysis and subcellular analysis is the study of genomics, transcriptomics, proteomics, metabolomics and cell–cell interactions at the single cell level. The concept of single-cell analysis originated in the 1970s. Before the discovery of heterogeneity, single-cell analysis mainly referred to the analysis or manipulation of an individual cell in a bulk population of cells at a particular condition using optical or electronic microscope. To date, due to the heterogeneity seen in both eukaryotic and prokaryotic cell populations, analyzing a single cell makes it possible to discover mechanisms not seen when studying a bulk population of cells. Technologies such as fluorescence-activated cell sorting (FACS) allow the precise isolation of selected single cells from complex samples, while high throughput single cell partitioning technologies, enable the simultaneous molecular analysis of hundreds or thousands of single unsorted cells; this is particularly useful for the analysis of transcriptome variation in genotypically identical cells, allowing the definition of otherwise undetectable cell subtypes. The development of new technologies is increasing our ability to analyze the genome and transcriptome of single cells, as well as to quantify their proteome and metabolome. Mass spectrometry techniques have become important analytical tools for proteomic and metabolomic analysis of single cells. Recent advances have enabled quantifying thousands of protein across hundreds of single cells, and thus make possible new types of analysis. In situ sequencing and fluorescence in situ hybridization (FISH) do not require that cells be isolated and are increasingly being used for analysis of tissues. | 1 | Applied and Interdisciplinary Chemistry |
*[http://www.arabianbusiness.com/mohammad-baloola-interview-beating-bulge-446743.html Mohammad Baloola interview: Beating the bulge – Arabian Business Magazine]
*[http://gulfnews.com/news/gulf/uae/education/diabetes-invention-inches-closer-to-development-1.942614 Diabetes invention inches closer to development – Gulf New Newspaper]
*[http://gulfnews.com/news/gulf/uae/education/graduate-invents-winning-diabetes-device-1.789567 Graduate invents winning diabetes device – Gulf New Newspaper]
*[http://gulftoday.ae/portal/c4302645-fb9d-44bf-8327-95ca2a5554cf.aspx Former AUST pupil in Arab elite-Gulf Today Newspaper] | 0 | Theoretical and Fundamental Chemistry |
With fewer ions, the electric field increases, resulting in electrons with energy of about 2 eV, which is enough to excite atoms and produce light. With longer glow discharge tubes, the longer space is occupied by a longer positive column, while the cathode layer remains the same. For example, with a neon sign, the positive column occupies almost the entire length of the tube. | 0 | Theoretical and Fundamental Chemistry |
External fans are provided to give sufficient air for combustion. The Primary air fan takes air from the atmosphere and, first warms the air in the air preheater for better economy. Primary air then passes through the coal pulverizers, and carries the coal dust to the burners for injection into the furnace. The Secondary air fan takes air from the atmosphere and, first warms the air in the air preheater for better economy. Secondary air is mixed with the coal/primary air flow in the burners.
The induced draft fan assists the FD fan by drawing out combustible gases from the furnace, maintaining slightly below atmospheric pressure in the furnace to avoid leakage of combustion products from the boiler casing. | 1 | Applied and Interdisciplinary Chemistry |
Sintering and hot isostatic pressing are processing techniques used to densify materials from a loosely packed "green body" into a solid object with physically merged grains. Sintering occurs below the melting point, and causes adjacent particles to merge at their boundaries, creating a strong bond between them. In hot isostatic pressing, a sintered material is placed in a pressure vessel and compressed from all directions (isostatically) in an inert atmosphere to affect densification. | 1 | Applied and Interdisciplinary Chemistry |
Lovastatin is an inhibitor of 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMG-CoA reductase), an enzyme that catalyzes the conversion of HMG-CoA to mevalonate.
Mevalonate is a required building block for cholesterol biosynthesis and lovastatin interferes with its production by acting as a reversible competitive inhibitor for HMG-CoA, which binds to the HMG-CoA reductase. Lovastatin is a prodrug, an inactive lactone in its native form, the gamma-lactone closed ring form in which it is administered, is hydrolysed in vivo to the β-hydroxy acid open ring form; which is the active form.
Lovastatin and other statins have been studied for their chemopreventive and chemotherapeutic effects. No such effects were seen in the early studies. More recent investigations revealed some chemopreventive and therapeutic effects, for certain types of cancer, especially in combination of statins with other anticancer drugs. It is likely that these effect are mediated by the properties of statins to reduce proteasome activity, leading to an accumulation of cyclin-dependent kinase inhibitors p21 and p27, and to subsequent G-phase arrest, as seen in cells of different cancer lines. | 0 | Theoretical and Fundamental Chemistry |
Fluorescence spectroscopy is a technique that is used to assay a sample using a fluorescent probe. DNA nucleotides themselves are not good candidates for this technique because they do not readily re-emit light upon light excitation. A fluorescent marker is needed to detect base flipping. 2-Aminopurine is a base that is structurally similar to adenine, but is very fluorescent when flipped out from the DNA duplex. It is commonly used to detect base flipping and has an excitation at 305‑320 nm and emission at 370 nm so that it well separated from the excitations of proteins and DNA. Other fluorescent probes used to study DNA base flipping are 6MAP (4‑amino‑6‑methyl‑7(8H)‑pteridone) and Pyrrolo‑C (3-[β-D-2-ribofuranosyl]-6-methylpyrrolo[2,3-d]pyrimidin-2(3H)-one). Time-resolved fluorescence spectroscopy is also employed to provide a more detailed picture of the extent of base flipping as well as the conformational dynamics occurring during base flipping. | 1 | Applied and Interdisciplinary Chemistry |
Porphyrins have been investigated as possible anti-inflammatory agents and evaluated on their anti-cancer and anti-oxidant activity. Several porphyrin-peptide conjugates were found to have antiviral activity against HIV in vitro. | 1 | Applied and Interdisciplinary Chemistry |
Waxes prepared with BTA are available commercially, the idea being that the BTA will prevent any reaction by chelating the surface copper and the wax acting as a physical barrier reducing exposure to water, oxygen, and chlorides; but coating an infected object with wax will not stop the problem. Storing the object in a completely dry or oxygen free environment will also prevent bronze disease as will isolation from contact with chlorides. | 1 | Applied and Interdisciplinary Chemistry |
Benzene is an excellent ligand in the organometallic chemistry of low-valent metals. Important examples include the sandwich and half-sandwich complexes, respectively, Cr(CH) and [[(Benzene)ruthenium dichloride dimer|[RuCl(CH)]]]. | 1 | Applied and Interdisciplinary Chemistry |
The enzymatic mechanism of influenza virus sialidase has been studied by Taylor et al., shown in Figure 1. The enzyme catalysis process has four steps. The first step involves the distortion of the α-sialoside from a C chair conformation (the lowest-energy form in solution) to a pseudoboat conformation when the sialoside binds to the sialidase. The second step leads to an oxocarbocation intermediate, the sialosyl cation. The third step is the formation of Neu5Ac initially as the α-anomer, and then mutarotation and release as the more thermodynamically stable β-Neu5Ac. | 0 | Theoretical and Fundamental Chemistry |
Copper chromite is an inorganic compound with the formula CuCrO. It is a black solid that is used to catalyze reactions in organic synthesis. | 0 | Theoretical and Fundamental Chemistry |
Lanthanides can be used because their small size (ionic radius) gives them the ability to replace metal ions inside protein complex such as calcium or nickel. The optical properties of lanthanide ions such as Ln(III) originate in the special features of their electronic [Xe]4f configurations. These configurations generate many electronic levels, the number of which is given by [14!/n!(14- n)!], translating into 3003 energy levels for Eu(III) and Tb(III).
The energies of these levels are well defined due to the shielding of the 4f orbitals by the filled 5s and 5p sub-shells, and are not very sensitive to the chemical environments in which the lanthanide ions are inserted. Inner-shell 4f-4f transitions span both the visible and near-infrared ranges. They are sharp and easily recognizable. Since these transitions are parity forbidden, the lifetimes of the excited states are long, which allows the use of time resolved spectroscopy, a definitive asset for bioassays and microscopy. The only drawback of f-f transitions are their faint oscillator strengths which may in fact be turned into an advantage.
The energy absorbed by the organic receptor (ligand) is transferred onto Ln(III) excited states, and sharp emission bands originating from the metal ion are detected after rapid internal conversion to the emitting level. The phenomenon is termed sensitization of the metal centered complex (also referred to as antenna effect) and is quite complex.
The energy migration path though goes through the long-lived triplet state of the ligand. Ln(III) ions are good quenchers of triplet states so that photobleaching is substantially reduced. The three types of transitions seen for lanthanide probes are: LMCT, 4f-5d, and intraconfigurational 4f-4f. The former two usually occur at energies too high to be relevant for bio-applications. | 1 | Applied and Interdisciplinary Chemistry |
Most pristine rivers will have a 5-day carbonaceous BOD below 1 mg/L. Moderately polluted rivers may have a BOD value in the range of 2 to 8 mg/L. Rivers may be considered severely polluted when BOD values exceed 8 mg/L. Municipal sewage that is efficiently treated by a three-stage process would have a value of about 20 mg/L or less. Untreated sewage varies, but averages around 600 mg/L in Europe and as low as 200 mg/L in the U.S., or where there is severe groundwater or surface water infiltration/inflow. The generally lower values in the U.S. derive from the much greater water use per capita than in other parts of the world. | 0 | Theoretical and Fundamental Chemistry |
Ore deposits formed by lateral secretion are formed by metamorphic reactions during shearing, which liberate mineral constituents such as quartz, sulfides, gold, carbonates, and oxides from deforming rocks, and focus these constituents into zones of reduced pressure or dilation such as faults. This may occur without much hydrothermal fluid flow, and this is typical of podiform chromite deposits.
Metamorphic processes also control many physical processes which form the source of hydrothermal fluids, outlined above. | 0 | Theoretical and Fundamental Chemistry |
A Metabolic Panel (MP) is a routine group of blood tests commonly used for health screenings, disease detection, and monitoring vital signs of hospitalized patients with specific medical conditions. MP panel analyzes common analytes in the blood to assess the functions of the kidneys and liver, as well as electrolyte and acid-base balances. There are two types of MPs - Basic Metabolic Panel (BMP) or Comprehensive Metabolic Panel (CMP). | 1 | Applied and Interdisciplinary Chemistry |
A dry well or drywell is an underground structure that disposes of unwanted water, most commonly surface runoff and stormwater, in some cases greywater or water used in a groundwater heat pump.
It is a gravity-fed, vertical underground system that can capture surface water from impervious surfaces, then store and gradually infiltrate the water into the groundwater aquifer.
Such structures are also called a dead well, absorbing well, negative well and soakaway or soakage pit in the United Kingdom or a soakwell or soak pit in Australia. | 1 | Applied and Interdisciplinary Chemistry |
A hyperaccumulator is a plant capable of growing in soil or water with high concentrations of metals, absorbing these metals through their roots, and concentrating extremely high levels of metals in their tissues. The metals are concentrated at levels that are toxic to closely related species not adapted to growing on the metalliferous soils. Compared to non-hyperaccumulating species, hyperaccumulator roots extract the metal from the soil at a higher rate, transfer it more quickly to their shoots, and store large amounts in leaves and roots. The ability to hyperaccumulate toxic metals compared to related species has been shown to be due to differential gene expression and regulation of the same genes in both plants.
Hyperaccumulating plants are of interest for their ability to extract metals from the soils of contaminated sites (phytoremediation) to return the ecosystem to a less toxic state. The plants also hold potential to be used to mine metals from soils with very high concentrations (phytomining) by growing the plants, then harvesting them for the metals in their tissues.
The genetic advantage of hyperaccumulation of metals may be that the toxic levels of heavy metals in leaves deter herbivores or increase the toxicity of other anti-herbivory metabolites. | 1 | Applied and Interdisciplinary Chemistry |
The distribution half-life of drospirenone is about 1.6 to 2 hours. The apparent volume of distribution of drospirenone is approximately 4 L/kg. The plasma protein binding of drospirenone is 95 to 97%. It is bound to albumin and 3 to 5% circulates freely or unbound. Drospirenone has no affinity for sex hormone-binding globulin (SHBG) or corticosteroid-binding globulin (CBG), and hence is not bound by these plasma proteins in the circulation. | 0 | Theoretical and Fundamental Chemistry |
Many ketones are cyclic. The simplest class have the formula , where n varies from 2 for cyclopropanone () to the tens. Larger derivatives exist. Cyclohexanone (), a symmetrical cyclic ketone, is an important intermediate in the production of nylon. Isophorone, derived from acetone, is an unsaturated, asymmetrical ketone that is the precursor to other polymers. Muscone, 3-methylpentadecanone, is an animal pheromone. Another cyclic ketone is cyclobutanone, having the formula . | 0 | Theoretical and Fundamental Chemistry |
A clinical trial protocol is a document used to define and manage the trial. It is prepared by a panel of experts. All study investigators are expected to strictly observe the protocol.
The protocol describes the scientific rationale, objective(s), design, methodology, statistical considerations and organization of the planned trial. Details of the trial are provided in documents referenced in the protocol, such as an investigator's brochure.
The protocol contains a precise study plan to assure safety and health of the trial subjects and to provide an exact template for trial conduct by investigators. This allows data to be combined across all investigators/sites. The protocol also informs the study administrators (often a contract research organization).
The format and content of clinical trial protocols sponsored by pharmaceutical, biotechnology or medical device companies in the United States, European Union, or Japan have been standardized to follow Good Clinical Practice guidance issued by the International Conference on Harmonization of Technical Requirements for Registration of Pharmaceuticals for Human Use (ICH). Regulatory authorities in Canada and Australia also follow ICH guidelines. Journals such as Trials, encourage investigators to publish their protocols. | 1 | Applied and Interdisciplinary Chemistry |
Across the 15th and 16th centuries there were primarily two different types of manufactured cannons. The wrought iron cannon and the cast-bronze cannon. Wrought iron guns were structurally composed of two layers: an inner tube of iron staves held together in a tight fit by an outer case of iron hoops. Bronze cannons on the other hand were cast in one piece similar to bells. The technique used in casting bronze cannons was so similar to the bell that the two were often looked upon as a connected enterprise.
Both iron and bronze cannons had their advantages and disadvantages. Forged iron cannons were up to ten times cheaper, but more unstable due to their piece built nature. Even without use, iron cannons were liable to rust away, while bronze cannons did not. Another reason for the dominance of bronze cannons was their aesthetic appeal. Because cannons were so important as displays of power and prestige, rulers liked to commission bronze cannons, which could be sculpted into fanciful designs containing artistic motifs or symbols. It was for all these reasons that the cast-bronze cannon became the preferred type by the late 1400s.
Some cannons cast in China during the 1370s may have been of steel rather than iron. | 1 | Applied and Interdisciplinary Chemistry |
In some terminal imido complexes, the M=N−C angle is 180° but often the angle is decidedly bent. Complexes of the type M=NH are assumed to be intermediates in nitrogen fixation by synthetic catalysts. | 0 | Theoretical and Fundamental Chemistry |
Orbiting Carbon Observatory-2 (OCO-2) is an American environmental science satellite which launched on 2 July 2014. A NASA mission, it is a replacement for the Orbiting Carbon Observatory which was lost in a launch failure in 2009. It is the second successful high-precision (better than 0.3%) observing satellite, after GOSAT. | 1 | Applied and Interdisciplinary Chemistry |
Metal-coded affinity tag is a method used for quantitative proteomics by mass spectrometry that uses a metal chelate complex 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetate (DOTA) coupled to different lanthanide ions. The metal complexes attach to the cysteine residues of proteins in a sample. | 0 | Theoretical and Fundamental Chemistry |
When two substituents are already present on the ring, the third substituent's new location is relatively predictable. If the existing substituents reinforce or the molecule is highly symmetric, there may be no ambiguity. Otherwise:
# The most-activating substituent usually controls over the less-activating one.
# In particular, ortho/para directors control over meta ones.
# When multiple substituents are comparably activating, steric hindrance dominates regioselectivity.
# In particular, the position between two substituents, each meta to the other, reacts last. | 0 | Theoretical and Fundamental Chemistry |
The word "alkali" is derived from Arabic al qalīy (or alkali), meaning the calcined ashes (see calcination), referring to the original source of alkaline substances. A water-extract of burned plant ashes, called potash and composed mostly of potassium carbonate, was mildly basic. After heating this substance with calcium hydroxide (slaked lime), a far more strongly basic substance known as caustic potash (potassium hydroxide) was produced. Caustic potash was traditionally used in conjunction with animal fats to produce soft soaps, one of the caustic processes that rendered soaps from fats in the process of saponification, one known since antiquity. Plant potash lent the name to the element potassium, which was first derived from caustic potash, and also gave potassium its chemical symbol K (from the German name Kalium), which ultimately derived from alkali. | 0 | Theoretical and Fundamental Chemistry |
The biuret test is a chemical test for proteins and polypeptides. It is based on the biuret reagent, a blue solution that turns violet upon contact with proteins, or any substance with peptide bonds. The test and reagent do not actually contain biuret; they are so named because both biuret and proteins have the same response to the test. | 0 | Theoretical and Fundamental Chemistry |
In superalloys strengthened by metal carbides, increasingly large carbide particles form preferentially at grain boundaries, preventing grain boundary sliding at high temperatures. This leads to an increase in the yield strength, and thus a yield strength anomaly. | 1 | Applied and Interdisciplinary Chemistry |
Fluoroform (CFH) has been employed as a trifluoromethylation reagent for aldehydes in combination with a strong base. | 0 | Theoretical and Fundamental Chemistry |
Synthesis of gold nanoparticles has been investigated utilizing Fusarium, Neurospora, Verticillium, yeasts, and Aspergillus. Extracellular gold nanoparticle synthesis was demonstrated by Fusarium oxysporum, Aspergillus niger, and cytosolic extracts from Candida albican. Intracellular gold nanoparticle synthesis has been demonstrated by a Verticillum species, V. luteoalbum, | 0 | Theoretical and Fundamental Chemistry |
Foodomics approach is used to analyze and establish the links between several substances presented in rosemary and the ability to cure colon cancer cells. There are thousands of chemical compounds in rosemary, but the ones that are able to help cure such disease are Carnosic acid (CA) and Carnosol (CS), which can be obtained by extracting rosemary via SFE. They have the potential to fight against and reduce the proliferation of human HT-29 colon cancer cells.
The experiment done by inserting rosemary extracts to the mice and collecting RNA and metabolites from each controlled and treated individual indicated that there is a correlation between the compounds used and the percentage of recovery from the cancer. This information is however never achievable without the help of foodomics knowledge as it was used to process data, analyze statistic, and identify biomarkers. Foodomics, coupled with transcriptomic data, shows that Carnosic acid leads to the accumulation of an antioxidant, glutothione (GSH). The chemical can be broken down to Cysteinylglycine, a naturally occurring dipeptide and an intermediate in the gamma glutamyl cycle. Moreover, the result from an integration of foodomics, transcriptomics and metabolomics reveals that provoking colon cancer cell compounds, such as N‐acetylputrescine, N‐acetylcadaverine, 5’MTA and γ‐aminobutyric acid, can also be lowered by CA treatment.
Thus, foodomics plays an important role in explaining the relationship between deadly disease, like colon cancer, and natural compounds existing in rosemary. Data obtained is useful in reaching another approach for tackling proliferation against cancer cells. | 1 | Applied and Interdisciplinary Chemistry |
Lipoexpediency refers to the beneficial effects of lipids in a cell or a tissue, primarily lipid-mediated signal transmission events, that may occur even in the setting of excess fatty acids. The term was coined as an antonym to lipotoxicity. | 1 | Applied and Interdisciplinary Chemistry |
Hypothermia has been applied therapeutically since antiquity. The Greek physician Hippocrates, the namesake of the Hippocratic Oath, advocated the packing of wounded soldiers in snow and ice. Napoleonic surgeon Baron Dominique Jean Larrey recorded that officers who were kept closer to the fire survived less often than the minimally pampered infantrymen. In modern times, the first medical article concerning hypothermia was published in 1945. This study focused on the effects of hypothermia on patients with severe head injury. In the 1950s, hypothermia received its first medical application, being used in intracerebral aneurysm surgery to create a bloodless field. Most of the early research focused on the applications of deep hypothermia, defined as a body temperature of . Such an extreme drop in body temperature brings with it a whole host of side effects, which made the use of deep hypothermia impractical in most clinical situations.
This period also saw sporadic investigation of more mild forms of hypothermia, with mild hypothermia being defined as a body temperature of . In the 1950s, Doctor Rosomoff demonstrated in dogs the positive effects of mild hypothermia after brain ischemia and traumatic brain injury. In the 1980s further animal studies indicated the ability of mild hypothermia to act as a general neuroprotectant following a blockage of blood flow to the brain. This animal data was supported by two landmark human studies that were published simultaneously in 2002 by the New England Journal of Medicine. Both studies, one occurring in Europe and the other in Australia, demonstrated the positive effects of mild hypothermia applied following cardiac arrest. Responding to this research, in 2003 the American Heart Association (AHA) and the International Liaison Committee on Resuscitation (ILCOR) endorsed the use of targeted temperature management following cardiac arrest. Currently, a growing percentage of hospitals around the world incorporate the AHA/ILCOR guidelines and include hypothermic therapies in their standard package of care for patients with cardiac arrest. Some researchers go so far as to contend that hypothermia represents a better neuroprotectant following a blockage of blood to the brain than any known drug. Over this same period a particularly successful research effort showed that hypothermia is a highly effective treatment when applied to newborn infants following birth asphyxia. Meta-analysis of a number of large randomised controlled trials showed that hypothermia for 72 hours started within 6 hours of birth significantly increased the chance of survival without brain damage. | 1 | Applied and Interdisciplinary Chemistry |
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