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Sucrose esters are off-white powders. Though produced from sucrose, sucrose esters do not have a sweet taste, but are bland or bitter. | 0 | Theoretical and Fundamental Chemistry |
Luciferin () is a generic term for the light-emitting compound found in organisms that generate bioluminescence. Luciferins typically undergo an enzyme-catalyzed reaction with molecular oxygen. The resulting transformation, which usually involves breaking off a molecular fragment, produces an excited state intermediate that emits light upon decaying to its ground state. The term may refer to molecules that are substrates for both luciferases and photoproteins. | 1 | Applied and Interdisciplinary Chemistry |
2D correlation analysis is frequently used for its main advantage: increasing the spectral resolution by spreading overlapping peaks over two dimensions and as a result simplification of the interpretation of one-dimensional spectra that are otherwise visually indistinguishable from each other. Further advantages are its ease of application and the possibility to make the distinction between band shifts and band overlap. Each type of spectral event, band shifting, overlapping bands of which the intensity changes in the opposite direction, band broadening, baseline change, etc. has a particular 2D pattern. See also the figure with the original dataset on the right and the corresponding 2D spectrum in the figure below. | 0 | Theoretical and Fundamental Chemistry |
In atomic physics, the spectral optical depth of a cloud of atoms can be calculated from the quantum-mechanical properties of the atoms. It is given bywhere
*d is the transition dipole moment;
*n is the number of atoms;
*ν is the frequency of the beam;
*c is the speed of light;
*ħ is Planck's constant;
*ε is the vacuum permittivity;
*σ the cross section of the beam;
*γ the natural linewidth of the transition. | 0 | Theoretical and Fundamental Chemistry |
This identification of the 's as asymptotic states is the justification for the in the denominator of the Lippmann–Schwinger equations. | 0 | Theoretical and Fundamental Chemistry |
Carbon label is a form of isotopic labeling where a carbon-12 atom is replaced with either a stable carbon-13 atom or radioactive carbon-11 or carbon-14 atoms in a chemical compound so as to tag (i.e. label) that position of the compound to assist in determining the way a chemical reaction proceeds i.e. the reaction mechanism. | 0 | Theoretical and Fundamental Chemistry |
1,1,1-Trichloroethane was first reported by Henri Victor Regnault in 1840. Industrially, it is usually produced in a two-step process from vinyl chloride. In the first step, vinyl chloride reacts with hydrogen chloride at 20-50 °C to produce 1,1-dichloroethane:
:CH=CHCl + HCl → CHCHCl
This reaction is catalyzed by a variety of Lewis acids, mainly aluminium chloride, iron(III) chloride, or zinc chloride. The 1,1-dichloroethane is then converted to 1,1,1-trichloroethane by reaction with chlorine under ultraviolet irradiation:
:CHCHCl + Cl → CHCCl + HCl
This reaction proceeds at 80-90% yield, and the hydrogen chloride byproduct can be recycled to the first step in the process. The major side-product is the related compound 1,1,2-trichloroethane, from which the 1,1,1-trichloroethane can be separated by distillation.
A somewhat smaller amount of 1,1,1-trichloroethane is produced from the reaction of 1,1-dichloroethene and hydrogen chloride in the presence of an iron(III) chloride catalyst:
:CH=CCl + HCl → CHCCl
1,1,1-Trichloroethane is sold with stabilizers because it is unstable with respect to dehydrochlorination and attacks some metals. Stabilizers comprise up to 8% of the formulation, including acid scavengers (epoxides, amines) and complexants. | 1 | Applied and Interdisciplinary Chemistry |
Artificial nucleic acid analogues have been designed and synthesized. They include peptide nucleic acid, morpholino- and locked nucleic acid, glycol nucleic acid, and threose nucleic acid. Each of these is distinguished from naturally occurring DNA or RNA by changes to the backbone of the molecules. | 1 | Applied and Interdisciplinary Chemistry |
The structure of cryptophanes contain 6 phenyl rings, mainly connected in 4 ways . Due to the phenyl groups and aliphatic chains, the cages inside cryptophanes are highly hydrophobic, suggesting the capability of capturing non-polar molecules. Based on this, cryptophanes can be employed to capture xenon in aqueous solution, which could be helpful in biological studies. | 0 | Theoretical and Fundamental Chemistry |
The gene gun, also known as a biolistic particle delivery system, is used to deliver transgenes, proteins, or RNA into the cell. It uses a micro-projectile delivery system that shoots coated particles of a typical heavy metal that has DNA of interest into cells using high speed. The genetic material will penetrate the cell and deliver the contents over a space area. The use of micro-projectile delivery systems is a technique known as biolistic. | 1 | Applied and Interdisciplinary Chemistry |
Sialic acids are a class of alpha-keto acid sugars with a nine-carbon backbone. The term "sialic acid" () was first introduced by Swedish biochemist Gunnar Blix in 1952. The most common member of this group is N-acetylneuraminic acid (Neu5Ac or NANA) found in animals and some prokaryotes.
Sialic acids are found widely distributed in animal tissues and related forms are found to a lesser extent in other organisms like in some micro-algae, bacteria and archaea. Sialic acids are commonly part of glycoproteins, glycolipids or gangliosides, where they decorate the end of sugar chains at the surface of cells or soluble proteins. However, sialic acids have been also observed in Drosophila embryos and other insects. Generally, plants seem not to contain or display sialic acids.
In humans the brain has the highest sialic acid content, where these acids play an important role in neural transmission and ganglioside structure in synaptogenesis. More than 50 kinds of sialic acid are known, all of which can be obtained from a molecule of neuraminic acid by substituting its amino group or one of its hydroxyl groups. In general, the amino group bears either an acetyl or a glycolyl group, but other modifications have been described. These modifications along with linkages have shown to be tissue specific and developmentally regulated expressions, so some of them are only found on certain types of glycoconjugates in specific cells. The hydroxyl substituents may vary considerably; acetyl, lactyl, methyl, sulfate, and phosphate groups have been found. | 0 | Theoretical and Fundamental Chemistry |
DNA damage affects splicing factors by altering their post-translational modification, localization, expression and activity. Furthermore, DNA damage often disrupts splicing by interfering with its coupling to transcription. DNA damage also has an impact on the splicing and alternative splicing of genes intimately associated with DNA repair. For instance, DNA damages modulate the alternative splicing of the DNA repair genes Brca1 and Ercc1. | 1 | Applied and Interdisciplinary Chemistry |
Many important engineered systems involve heat transfer. Some examples are the heating and cooling of process streams, phase changes, distillation, etc. The basic principle is the Fourier's law which is expressed as follows for a static system:
The net flux of heat through a system equals the conductivity times the rate of change of temperature with respect to position.
For convective transport involving turbulent flow, complex geometries, or difficult boundary conditions, the heat transfer may be represented by a heat transfer coefficient.
where A is the surface area, is the temperature driving force, Q is the heat flow per unit time, and h is the heat transfer coefficient.
Within heat transfer, two principal types of convection can occur:
* Forced convection can occur in both laminar and turbulent flow. In the situation of laminar flow in circular tubes, several dimensionless numbers are used such as Nusselt number, Reynolds number, and Prandtl number. The commonly used equation is .
* Natural or free convection is a function of Grashof and Prandtl numbers. The complexities of free convection heat transfer make it necessary to mainly use empirical relations from experimental data.
Heat transfer is analyzed in packed beds, nuclear reactors and heat exchangers. | 1 | Applied and Interdisciplinary Chemistry |
K. C. Nicolaou was born on July 5, 1946, in Karavas, Cyprus where he grew up and went to school until the age of 18. In 1964, he went to England where he spent two years learning English and preparing to enter University. He studied chemistry at the University of London (B.Sc., 1969, Bedford College; Ph.D. 1972, University College London, with Professors F. Sondheimer and P. J. Garratt). In 1972, he moved to the United States and, after postdoctoral appointments at Columbia University (1972–1973, Professor T. J. Katz) and Harvard University (1973–1976, Professor E. J. Corey), he joined the faculty at the University of Pennsylvania where he became the Rhodes-Thompson Professor of Chemistry. While at Penn, he won the prestigious Sloan Fellowship.
In 1989, he relocated to San Diego, where he took up a joint appointment at the University of California, San Diego, where he served as Professor of Chemistry, and The Scripps Research Institute, where he was Darlene Shiley Professor of Chemistry and Chairman of the Department of Chemistry. In 1996, he was appointed Aline W. and L.S. Skaggs Professor of Chemical Biology in The Skaggs Institute for Chemical Biology, The Scripps Research Institute. From 2005 to 2011, he directed Chemical Synthesis Laboratory @ ICES-A*STAR, Singapore. In 2013, Nicolaou moved to Rice University.
The Nicolaou group is active in the field of organic chemistry with research interests in methodology development and total synthesis. He is responsible for the synthesis of many complex molecules found in nature, such as Taxol and vancomycin. His groups route to Taxol, completed in 1994 at roughly the same time as a synthesis by the group of Robert A. Holton, attracted national news media attention due to Taxols structural complexity and its potent anti-cancer activity. | 0 | Theoretical and Fundamental Chemistry |
Nitrates are used as fertilizers in agriculture because of their high solubility and biodegradability. The main nitrate fertilizers are ammonium, sodium, potassium, calcium, and magnesium salts. Several billion kilograms are produced annually for this purpose. | 0 | Theoretical and Fundamental Chemistry |
Translations, denoted by T, where v is a vector in R have the effect of shifting the plane in the direction of v. That is, for any point p in the plane,
:or in terms of (x, y) coordinates,
A translation can be seen as a composite of two parallel reflections. | 0 | Theoretical and Fundamental Chemistry |
Major developments: Gunpowder fireworks are mentioned. Ships are equipped with trebuchets for hurling bombs. Earliest recorded usage of gunpowder artillery in ship to ship combat, first mention of the fire lance in battle, and the earliest possible depiction of a cannon appears. | 1 | Applied and Interdisciplinary Chemistry |
Flame treatment is a controlled, rapid, cost-effective method of increasing surface energy and wettability of polyolefins and metallic components. This high-temperature plasma treatment uses ionized gaseous oxygen via jet flames across a surface to add polar functional groups while melting the surface molecules, locking them into place upon cooling.
Thermoplastic polyethylene and polypropylene treated with brief oxygen plasma exposure have seen contact angles as low as 22°, and the resulting surface modification can last years with proper packaging. Flame plasma treatment has become increasingly popular with intravascular devices such as balloon catheters due to the precision and cost-effectiveness demanded in the medical industry. | 0 | Theoretical and Fundamental Chemistry |
While some experiments have claimed a discovery of neutrinoless double beta decay, modern searches have found no evidence for the decay. | 0 | Theoretical and Fundamental Chemistry |
In 1965, Brill launched another important innovation in glass analysis, the comparison of interlaboratory experiments in order to verify analytical results (Brill 1965). ‘Originally inspired by a plea from W E S Turner’, according to Freestone, Brill first mooted his idea at the VIIth International Congress on Glass, in Brussels (Brill 1965a, I. Freestone, pers. comm. 2009). It wasn’t until the VIIIth International Congress on Glass in 1968, however, that Brill fully launched his concept of an ‘analytical round robin’, having distributed a number of reference glasses to be tested in different laboratories using a range of current techniques including X-ray fluorescence and neutron activation analysis (1968, 49). When discussing his motive for the experiment, Brill aptly stated: The truth is that the chemical analysis of glasses is a difficult undertaking and still remains in some senses an art (1968, 49). By conducting the round robin experiment, Brill hoped the results gathered from different laboratories would help ‘correlate [...] earlier results’ and ‘calibrate future analyses in reference to one another’, as well as suggest which out of the analytical procedures used was the most accurate and effective (1968, 49). The results of the round robin were presented at the IXth International Congress on Glass in 1971, and showed that, as Brill suspected, there was poor agreement between certain identified elements, and therefore these might be ‘troublesome’ generally across analyses (1971, 97). These included calcium, aluminium, lead and barium, among others (Brill 1971). Aside from their correctional potential, the results, from 45 different laboratories in 15 countries, also provided an enormous data set from which, Brill suggested, the participants could ‘evaluate their own methods and procedures against the findings of other analysts’ (1971, 97). At the time, Brill could hardly have suspected that the data would go on to have such great import, but Croegaards generation of preferred glass compositions, from statistical analysis of the data, were used successfully by many people until Brills own reference guide was published in 1999 (I. Freestone, pers. comm., 2009). | 0 | Theoretical and Fundamental Chemistry |
O-Nitroso compounds are similar to S-nitroso compounds, but are less reactive because the oxygen atom is less nucleophilic than the sulfur atom. The formation of an alkyl nitrite from an alcohol and nitrous acid is a common example:
:ROH + HONO → RONO + HO | 0 | Theoretical and Fundamental Chemistry |
Sandra Pizzarello was born in Venice, Italy in 1933. In 1955, she graduated summa cum laude from the University of Padua earning her Doctor of Biological Sciences degree under her adviser Professor Roncato. Pizzarello went on to work as a research associate developing tranquilizers for Farmitalia Research Laboratories in the Department of Neuropharmacology. Over the course of several years, Pizzarello transitioned from research to raising a family. Following a career opportunity for her husband, an aeronautical engineer and computer scientist, she moved her family to Phoenix, Arizona in 1970.
Once Pizzarello's youngest of four children finished primary school, her focus returned to her career after a decade away from scientific research. She audited a graduate biochemistry seminar course at ASU where she met Professor John Cronin, future co-discoverer of amino acid enantiomeric excess in meteorites. Due to her outstanding performance in the course, she was offered a job to work with Cronin at the university as a research professor in analyzing the recently recovered Murchison meteorite.
Sandra Pizzarello died on October 24, 2021. | 1 | Applied and Interdisciplinary Chemistry |
Hellenistic and Graeco-Roman forms are more conventional, and the new motives that belong to these periods are mostly floral. Busts and masks are the usual handle-plaques and spouts; heads and limbs of various animals are allotted certain decorative functions, as for instance the spirited mules' heads mentioned by Juvenal, which formed the elbow-rests of dining couches. These structural pieces are frequently inlaid with silver and niello. Bronze chairs and tables were commonly used in Hellenistic and Roman houses, and largely took the place of monumental vases that were popular in earlier days. Small household articles, such as lamps, when made of bronze are usually Roman, and a peculiarly Roman class of personal ornaments is a large bronze brooch inlaid with coloured enamels, a technique which seems to have had a Gaulish origin. | 1 | Applied and Interdisciplinary Chemistry |
In biochemical protein targeting, a peroxisomal targeting signal (PTS) is a region of the peroxisomal protein that receptors recognize and bind to. It is responsible for specifying that proteins containing this motif are localised to the peroxisome. | 1 | Applied and Interdisciplinary Chemistry |
When the Landau constant is negative, , we must include a negative term of higher order to arrest the unbounded increase of the perturbation. In this case, the Landau equation becomes
The limiting amplitude then becomes
where the plus sign corresponds to the stable branch and the minus sign to the unstable branch. There exists a value of a critical value where the above two roots are equal () such that , indicating that the flow in the region is metastable', that is to say, in the metastable region, the flow is stable to infinitesimal perturbations, but not to finite amplitude perturbations. | 1 | Applied and Interdisciplinary Chemistry |
In the United States, immediate release (IR) formulations of dextroamphetamine sulfate are available generically as 5 mg and 10 mg tablets, marketed by Barr (Teva Pharmaceutical Industries), Mallinckrodt Pharmaceuticals, Wilshire Pharmaceuticals, Aurobindo Pharmaceutical USA and CorePharma. Previous IR tablets sold under the brand names Dexedrine and Dextrostat have been discontinued but in 2015, IR tablets became available by the brand name Zenzedi, offered as 2.5 mg, 5 mg, 7.5 mg, 10 mg, 15 mg, 20 mg and 30 mg tablets. Dextroamphetamine sulfate is also available as a controlled-release (CR) capsule preparation in strengths of 5 mg, 10 mg, and 15 mg under the brand name Dexedrine Spansule, with generic versions marketed by Barr and Mallinckrodt. A bubblegum flavored oral solution is available under the brand name ProCentra, manufactured by FSC Pediatrics, which is designed to be an easier method of administration in children who have difficulty swallowing tablets, each 5 mL contains 5 mg dextroamphetamine. The conversion rate between dextroamphetamine sulfate to amphetamine free base is .728.
In Australia, dexamfetamine is available in bottles of 100 instant release 5 mg tablets as a generic drug or slow release dextroamphetamine preparations may be compounded by individual chemists. In the United Kingdom, it is available in 5 mg instant release sulfate tablets under the generic name dexamfetamine sulfate as well as 10 mg and 20 mg strength tablets under the brand name Amfexa. It is also available in generic dexamfetamine sulfate 5 mg/ml oral sugar-free syrup. The brand name Dexedrine was available in the United Kingdom prior to UCB Pharma disinvesting the product to another pharmaceutical company (Auden Mckenzie). | 0 | Theoretical and Fundamental Chemistry |
The ATP test is a process of rapidly measuring actively growing microorganisms through detection of adenosine triphosphate, or ATP. | 1 | Applied and Interdisciplinary Chemistry |
DNA expression requires the transfection of suitable host cells. Typically, either bacterial, yeast, insect, or mammalian cells (such as Human Embryonic Kidney cells or CHO cells) are used as host cells.
Following transplantation into the host organism, the foreign DNA contained within the recombinant DNA construct may or may not be expressed. That is, the DNA may simply be replicated without expression, or it may be transcribed and translated and a recombinant protein is produced. Generally speaking, expression of a foreign gene requires restructuring the gene to include sequences that are required for producing an mRNA molecule that can be used by the host's translational apparatus (e.g. promoter, translational initiation signal, and transcriptional terminator). Specific changes to the host organism may be made to improve expression of the ectopic gene. In addition, changes may be needed to the coding sequences as well, to optimize translation, make the protein soluble, direct the recombinant protein to the proper cellular or extracellular location, and stabilize the protein from degradation. | 1 | Applied and Interdisciplinary Chemistry |
The French police officer Alphonse Bertillon was the first to apply the anthropological technique of anthropometry to law enforcement, thereby creating an identification system based on physical measurements. Before that time, criminals could be identified only by name or photograph. Dissatisfied with the ad hoc methods used to identify captured criminals in France in the 1870s, he began his work on developing a reliable system of anthropometrics for human classification.
Bertillon created many other forensics techniques, including forensic document examination, the use of galvanoplastic compounds to preserve footprints, ballistics, and the dynamometer, used to determine the degree of force used in breaking and entering. Although his central methods were soon to be supplanted by fingerprinting, "his other contributions like the mug shot and the systematization of crime-scene photography remain in place to this day." | 0 | Theoretical and Fundamental Chemistry |
The presence of methane in the atmosphere of Mars is an area of ongoing research and a highly contentious subject. Because of its tendency to be destroyed in the atmosphere by photochemistry, the presence of excess methane on a planet can indicate that there must be an active source. With life being the strongest source of methane on Earth, observing a disequilibrium in the methane abundance on another planet could be a viable biosignature.
Since 2004, there have been several detections of methane in the Mars atmosphere by a variety of instruments onboard orbiters and ground-based landers on the Martian surface as well as Earth-based telescopes. These missions reported values anywhere between a background level ranging between 0.24 and 0.65 parts per billion by volume (p.p.b.v.) to as much as 45 ± 10 p.p.b.v.
However, recent measurements using the ACS and NOMAD instruments on board the ESA-Roscosmos ExoMars Trace Gas Orbiter have failed to detect any methane over a range of latitudes and longitudes on both Martian hemispheres. These highly sensitive instruments were able to put an upper bound on the overall methane abundance at 0.05 p.p.b.v. This nondetection is a major contradiction to what was previously observed with less sensitive instruments and will remain a strong argument in the ongoing debate over the presence of methane in the Martian atmosphere.
Furthermore, current photochemical models cannot explain the presence of methane in the atmosphere of Mars and its reported rapid variations in space and time. Neither its fast appearance nor disappearance can be explained yet. To rule out a biogenic origin for the methane, a future probe or lander hosting a mass spectrometer will be needed, as the isotopic proportions of carbon-12 to carbon-14 in methane could distinguish between a biogenic and non-biogenic origin, similarly to the use of the δ13C standard for recognizing biogenic methane on Earth. | 1 | Applied and Interdisciplinary Chemistry |
Numerical and theoretical considerations prompted the development of bimodal AFM. The method was initially thought to enhance topographic contrast in air environments. Three subsequent advances such as the capability to detect non-topography properties such electrostatic and magnetic interactions; imaging in liquid and ultra-high vacuum and its genuine quantitative features set the stage for further developments and applications. | 0 | Theoretical and Fundamental Chemistry |
The concept of natural products dates back to the early 19th century, when the foundations of organic chemistry were laid. Organic chemistry was regarded at that time as the chemistry of substances that plants and animals are composed of. It was a relatively complex form of chemistry and stood in stark contrast to inorganic chemistry, the principles of which had been established in 1789 by the Frenchman Antoine Lavoisier in his work Traité Élémentaire de Chimie. | 1 | Applied and Interdisciplinary Chemistry |
Biological photovoltaic systems that employ whole organisms are the most robust type, and lifetimes of multiple months have been observed. The insulating outer membranes of whole cells impedes electron transfer from the sites of electron generation inside the cell to the anode. As a result, conversion efficiencies are low unless lipid-soluble redox mediators are included in the system. Cyanobacteria are typically used in these systems because their relatively simple arrangement of intracellular membranes compared to eukaryotic algae facilitates electron export. Potential catalysts such as platinum can be used to increase permeability of the cellular membrane. | 0 | Theoretical and Fundamental Chemistry |
Economizers (US and Oxford spelling), or economisers (UK), are mechanical devices intended to reduce energy consumption, or to perform useful function such as preheating a fluid. The term economizer is used for other purposes as well. Boiler, power plant, heating, refrigeration, ventilating, and air conditioning (HVAC) uses are discussed in this article. In simple terms, an economizer is a heat exchanger. | 0 | Theoretical and Fundamental Chemistry |
Microarray data was found to be more useful when compared to other similar datasets. The sheer volume of data, specialized formats (such as MIAME), and curation efforts associated with the datasets require specialized databases to store the data. A number of open-source data warehousing solutions, such as InterMine and [http://www.biomart.org/ BioMart], have been created for the specific purpose of integrating diverse biological datasets, and also support analysis. | 1 | Applied and Interdisciplinary Chemistry |
Enantiopure compounds consist of only one of the two enantiomers. Enantiopurity is of practical importance since such compositions have improved therapeutic efficacy. The switch from a racemic drug to an enantiopure drug is called a chiral switch. In many cases, the enantiomers have distinct effects. One case is that of Propoxyphene. The enantiomeric pair of propoxyphene is separately sold by Eli Lilly and company. One of the partner is dextropropoxyphene, an analgesic agent (Darvon) and the other is called levopropoxyphene, an effective antitussive (Novrad). It is interesting to note that the trade names of the drugs, DARVON and NOVRAD, also reflect the chemical mirror-image relationship. In other cases, there may be no clinical benefit to the patient. In some jurisdictions, single-enantiomer drugs are separately patentable from the racemic mixture. It is possible that only one of the enantiomers is active. Or, it may be that both are active, in which case separating the mixture has no objective benefits, but extends the drug's patentability. | 0 | Theoretical and Fundamental Chemistry |
Other remedies include using improved monitoring methods, trying to improve predictability, and testing new potential methods of controlling HABs. Some countries surrounding the Baltic Sea, which has the world's largest dead zone, have considered using massive geoengineering options, such as forcing air into bottom layers to aerate them.
Mathematical models are useful to predict future algal blooms. | 0 | Theoretical and Fundamental Chemistry |
Neptunium silicide is a binary inorganic compound of neptunium and silicon with the chemical formula . The compound forms crystals and does not dissolve in water. | 0 | Theoretical and Fundamental Chemistry |
Continuous monitoring and adaptive control (CMAC) is a category of stormwater best management practice that allows for a wider range of operation of detention and retention ponds. CMAC systems typically consist of a water level sensor, an actuated valve, and an internet connection.
Specific applications of CMAC include flood protection, water quality treatment, water reuse, and channel protection. | 1 | Applied and Interdisciplinary Chemistry |
The parameters of the Rosin–Rammler distribution can be determined by refactoring the distribution function to the form
Hence the slope of the line in a plot of
: versus
yields the parameter and is determined by substitution into | 0 | Theoretical and Fundamental Chemistry |
Understanding the mechanical properties of Heusler compounds is paramount for temperature-sensitive applications (e.g. thermoelectrics) for which some sub-classes of Heusler compounds are used. However, experimental studies are rarely encountered in literature. In fact, the commercialization of these compounds is limited by the materials ability to undergo intense, repetitive thermal cycling and resist cracking from vibrations. An appropriate measure for crack resistance is the materials toughness, which typically scales inversely with another important mechanical property: the mechanical strength. In this section, we highlight existing experimental and computational studies on the mechanical properties of Heusler alloys. Note that the mechanical properties of such a compositionally-diverse class of materials is expectedly dependent on the chemical composition of the alloys themselves, and therefore trends in mechanical properties are difficult to identify without a case-by-case study.
The elastic modulus values of half-Heusler alloys range from 83 to 207 GPa, whereas the bulk modulus spans a tighter range from 100 GPa in HfNiSn to 130 GPa in TiCoSb. A collection of various density functional theory (DFT) calculations show that half-Heusler compounds are predicted to have a lower elastic, shear, and bulk modulus than in quaternary-, full-, and inverse-Hausler alloys. DFT also predicts a decrease in elastic modulus with temperature in NiXAl (X=Sc, Ti, V), as well as an increase in stiffness with pressure. The decrease in modulus with respect to temperature is also observed in TiNiSn, ZrNiSn, and HfNiSn, where ZrNiSn has the highest modulus and Hf has the lowest. This phenomenon can be explained by the fact that the elastic modulus decreases with increasing interatomic separation: as temperature increases, the atomic vibrations also increase, resulting in a larger equilibrium interatomic separation.
The mechanical strength is also rarely studied in Heusler compounds. One study has shown that, in off-stoichiometric NiMnIn, the material reaches a peak strength of 475 MPa at 773 K, which drastically reduces to below 200 MPa at 973 K. In another study, a polycrystalline Heusler alloy composed of the Ni-Mn-Sn ternary composition space was found to possess a peak compressive strength of about 2000 MPa with plastic deformation up to 5%. However, the addition of Indium to the Ni-Mn-Sn ternary alloy not only increases the porosity of the samples, but it also reduces the compressive strength to 500 MPa. It is unclear from the study what percentage of the porosity increase from the indium addition reduces the strength. Note that this is opposite to the outcome expected from solid solution strengthening, where adding indium to the ternary system slows dislocation movement through dislocation-solute interaction and subsequently increases the material's strength.
The fracture toughness can also be tuned with composition modifications. For example, the average toughness of Ti(Zr, Hf)NiSn ranges from 1.86 MPa m to 2.16 MPa m, increasing with Zr/Hf content. The preparation of samples may affect the measured fracture toughness however, as elaborated by O’Connor et al. In their study, samples of TiHfCoIrSbSn were prepared using three different methods: a high-temperature solid state reaction, high-energy ball milling, and a combination of both. The study found higher fracture toughness in samples prepared without a high-energy ball milling step of 2.7 MPa m to 4.1 MPa m, as opposed to samples that were prepared with ball milling of 2.2 MPa m to 3.0 MPa m. Fracture toughness is sensitive to inclusions and existing cracks in the material, so it is as expected dependent on the sample preparation. | 1 | Applied and Interdisciplinary Chemistry |
FMRFamide patterning over the course of embryonic life has been recorded through immunofluorescence. Embryos at 0 to 144 hours (6 days) post cleavage were extracted from the egg mass and fixed in 4% PFA for 2 hrs at room temperature. Embryos older than 4 days were pre-treated with 0.5% ethylenediaminetetraacetic acid (EDTA) solution in PBS for 5 minutes to improve primary antibody penetration, and then fixed in 4% PFA for 2 hours at room temperature. Embryos were then washed overnight in 4% Triton X-100 in PBS and incubated in blocking solution, 1% normal goal serum in PBS, overnight at 4 °C.
After blocking overnight, embryos were treated with a primary antibody solution at 1:2000 (in NGS/PBS). Secondary antibody tagged with fluorescein isothiocyanate (FITC)-conjugated anti-rabbit IgG (polyclonal) was incubated at 1:20, overnight at 4 °C. Embryos were then mounted on a slide and viewed with fluorescent microscopy. | 1 | Applied and Interdisciplinary Chemistry |
Several simple methods for encoding text have been proposed. Most of these involve translating each letter into a corresponding "codon", consisting of a unique small sequence of nucleotides in a lookup table. Some examples of these encoding schemes include Huffman codes, comma codes, and alternating codes. | 1 | Applied and Interdisciplinary Chemistry |
10-Hydroxydecanic acid is a specialized saturated fatty acid that is a minor constituent of royal jelly. It was scientifically discovered in 1957. | 1 | Applied and Interdisciplinary Chemistry |
*Boiler design
*Combustion engines
*Cooling systems
**Cooling of computer chips
*Heat exchangers
*HVAC
*Process Fired Heaters
*Refrigeration Systems
*Compressed Air Systems
*Solar heating
*Thermal insulation
*Thermal power plants | 1 | Applied and Interdisciplinary Chemistry |
Microbes employed include:
* Yeast
** Saccharomyces cerevisiae
** Pichia pastoris
** Candida utilis
** Torulopsis corallina
** Geotrichum candidum
* Fungi (Mycoprotein)
** Aspergillus oryzae
** Fusarium venenatum
** Sclerotium rolfsii
** Polyporus
** Trichoderma
** Scytalidium acidophilum
* Bacteria
** Rhodobacter capsulatus
**Methylophilus methylotrophus
**Metylococcus capsulatus
* Algae
** Spirulina (dietary supplement)
** Chlorella | 1 | Applied and Interdisciplinary Chemistry |
McDermott's research exploits Nuclear Magnetic Resonance to study the functions, structures, and dynamics of proteins including enzymes, viral proteins, membrane proteins and amyloid proteins. In particular, her group uses and develops solid state methodology including high-resolution magic angle spinning. | 0 | Theoretical and Fundamental Chemistry |
Macromolecular structure validation is the process of evaluating reliability for 3-dimensional atomic models of large biological molecules such as proteins and nucleic acids. These models, which provide 3D coordinates for each atom in the molecule (see example in the image), come from structural biology experiments such as x-ray crystallography or nuclear magnetic resonance (NMR). The validation has three aspects: 1) checking on the validity of the thousands to millions of measurements in the experiment; 2) checking how consistent the atomic model is with those experimental data; and 3) checking consistency of the model with known physical and chemical properties.
Proteins and nucleic acids are the workhorses of biology, providing the necessary chemical reactions, structural organization, growth, mobility, reproduction, and environmental sensitivity. Essential to their biological functions are the detailed 3D structures of the molecules and the changes in those structures. To understand and control those functions, we need accurate knowledge about the models that represent those structures, including their many strong points and their occasional weaknesses.
End-users of macromolecular models include clinicians, teachers and students, as well as the structural biologists themselves, journal editors and referees, experimentalists studying the macromolecules by other techniques, and theoreticians and bioinformaticians studying more general properties of biological molecules. Their interests and requirements vary, but all benefit greatly from a global and local understanding of the reliability of the models. | 1 | Applied and Interdisciplinary Chemistry |
A direct repeat with no intervening nucleotides between the initial sequence and its downstream copy is a Tandem repeat. The nucleotide sequence written in bold characters signifies the repeated sequence.
Linguistically, a typical tandem repeat is comparable to stuttering, or deliberately repeated words, as in "bye-bye". | 1 | Applied and Interdisciplinary Chemistry |
The Min proteins prevent the FtsZ ring from being placed anywhere but near the mid cell and are hypothesized to be involved in a spatial regulatory mechanism that links size increases prior to cell division to FtsZ polymerization in the middle of the cell. | 1 | Applied and Interdisciplinary Chemistry |
the Atlantic Station project in Atlanta, was the largest brownfield redevelopment in the United States. Dayton, like many other cities in the region, is developing Tech Town in order to attract technology-based firms to Dayton and revitalize the downtown area. In Homestead, Pennsylvania, the site once occupied by Carnegie Steel has been converted into a successful commercial center, The Waterfront.
Pittsburgh, Pennsylvania, has successfully converted numerous former steel mill sites into high-end residential, shopping, and offices. Examples of brownfield redevelopment in Pittsburgh include:
* In Pittsburgh's Squirrel Hill neighborhood, a former slag dump for steel mills was turned into a $243 million residential development called Summerset at Frick Park.
* In Pittsburgh's South Side neighborhood, a former LTV Steel mill site was transformed into Southside Works, a mixed-use development that includes high-end entertainment, retail, offices, and housing.
* In the Hazelwood (Pittsburgh) neighborhood, a former Jones and Laughlin steel mill site was transformed into a $104 million office park called Pittsburgh Technology Center.
* In Herrs Island, a island on the western bank of the Allegheny River, a former rail stop for livestock and meatpacking was transformed into Washingtons Landing, a waterfront center for commerce, manufacturing, recreation and upscale housing | 1 | Applied and Interdisciplinary Chemistry |
The President of the United States is authorized to declare each May "Steelmark Month" to recognize the contribution made by the steel industry to the United States. | 1 | Applied and Interdisciplinary Chemistry |
*Thomas Hipke, Günther Lange, René Poss: Taschenbuch für Aluminiumschäume. Aluminium-Verlag, Düsseldorf 2007, .
*Hannelore Dittmar-Ilgen: Metalle lernen schwimmen. In: Dies.: Wie der Kork-Krümel ans Weinglas kommt. Hirzel, Stuttgart 2006, , S. 74. | 0 | Theoretical and Fundamental Chemistry |
Tosyl azide is one of the most stable azide compounds but is still regarded as a potential explosive and should be carefully stored, while particular caution is vital for all reactions in which it is heated at or above 100 °C. The initial temperature of the explosive decomposition is about 120 °C. | 0 | Theoretical and Fundamental Chemistry |
Bimetallic materials are materials that are made out of two different metals or alloys that are tightly bonded together. A good example of a bimetallic material would be a bimetallic strip which is used in some kinds of thermometers. In ISCR, bimetallic materials are small pieces of metals that are coated lightly with a catalyst such as palladium, silver, or platinum. The catalyst drives a faster reaction and the small size of the particles allows them to effectively move into and remain in the target zone. | 1 | Applied and Interdisciplinary Chemistry |
Like the two-hybrid system, phage display is used for the high-throughput screening of protein interactions. In the case of M13 filamentous phage display, the DNA encoding the protein or peptide of interest is ligated into the pIII or pVIII gene, encoding either the minor or major coat protein, respectively. Multiple cloning sites are sometimes used to ensure that the fragments are inserted in all three possible reading frames so that the cDNA fragment is translated in the proper frame. The phage gene and insert DNA hybrid is then inserted (a process known as "transduction") into E. coli bacterial cells such as TG1, SS320, ER2738, or XL1-Blue E. coli. If a "phagemid" vector is used (a simplified display construct vector) phage particles will not be released from the E. coli cells until they are infected with helper phage, which enables packaging of the phage DNA and assembly of the mature virions with the relevant protein fragment as part of their outer coat on either the minor (pIII) or major (pVIII) coat protein.
By immobilizing a relevant DNA or protein target(s) to the surface of a microtiter plate well, a phage that displays a protein that binds to one of those targets on its surface will remain while others are removed by washing. Those that remain can be eluted, used to produce more phage (by bacterial infection with helper phage) and to produce a phage mixture that is enriched with relevant (i.e. binding) phage. The repeated cycling of these steps is referred to as panning, in reference to the enrichment of a sample of gold by removing undesirable materials.
Phage eluted in the final step can be used to infect a suitable bacterial host, from which the phagemids can be collected and the relevant DNA sequence excised and sequenced to identify the relevant, interacting proteins or protein fragments.
The use of a helper phage can be eliminated by using bacterial packaging cell line technology.
Elution can be done combining low-pH elution buffer with sonification, which, in addition to loosening the peptide-target interaction, also serves to detach the target molecule from the immobilization surface. This ultrasound-based method enables single-step selection of a high-affinity peptide. | 1 | Applied and Interdisciplinary Chemistry |
Harmful algal blooms in freshwater lakes and rivers, or at estuaries, where rivers flow into the ocean, are caused by cyanobacteria, which are commonly referred to as "blue-green algae", but are in fact prokaryotic bacteria, as opposed to algae which are eukaryotes. Some cyanobacteria, including the widespread genus Microsystis, can produce hazardous cyanotoxins such as microcystins, which are hepatotoxins that harm the liver of mammals. Other types of cyanobacteria can also produce hepatotoxins, as well as neurotoxins, cytotoxins, and endotoxins. Water purification plants may be unable to remove these toxins, leading to increasingly common localised advisories against drinking tap water, as happened in Toledo, Ohio in August 2014.
In August 2021, there were 47 lakes confirmed to have algal blooms in New York State alone. In September 2021, Spokane Countys Environmental Programs issued a HAB alert for Newman Lake following tests showing potentially harmful toxicity levels for cyanobacteria, while in the same month record-high levels of microcystins were reported leading to an extended Do Not Drink advisory for 280 households at Clear Lake, Californias second-largest freshwater lake. Water conditions in Florida, meanwhile, continue to deteriorate under increasing nutrient inflows, causing severe HAB events in both freshwater and marine areas.
HABs also cause harm by blocking the sunlight used by plants and algae to photosynthesise, or by depleting the dissolved oxygen needed by fish and other aquatic animals, which can lead to fish die-offs. When such oxygen-depleted water covers a large area for an extended period of time, it can become hypoxic or even anoxic; these areas are commonly called dead zones. These dead zones can be the result of numerous different factors ranging from natural phenomenon to deliberate human intervention, and are not just limited to large bodies of fresh water as found in the great lakes, but are also prone to bodies of salt water as well. | 0 | Theoretical and Fundamental Chemistry |
Examples for more low-tech, often less expensive sewage treatment systems are shown below. They often use little or no energy. Some of these systems do not provide a high level of treatment, or only treat part of the sewage (for example only the toilet wastewater), or they only provide pre-treatment, like septic tanks. On the other hand, some systems are capable of providing a good performance, satisfactory for several applications. Many of these systems are based on natural treatment processes, requiring large areas, while others are more compact. In most cases, they are used in rural areas or in small to medium-sized communities.
For example, waste stabilization ponds are a low cost treatment option with practically no energy requirements but they require a lot of land. Due to their technical simplicity, most of the savings (compared with high tech systems) are in terms of operation and maintenance costs.
* Anaerobic digester types and anaerobic digestion, for example:
** Upflow anaerobic sludge blanket reactor
** Septic tank
** Imhoff tank
* Constructed wetland (see also biofilters)
* Decentralized wastewater system
* Nature-based solutions
* On-site sewage facility
* Sand filter
* Vermifilter
* Waste stabilization pond with sub-types:
** e.g. Facultative ponds, high rate ponds, maturation ponds
Examples for systems that can provide full or partial treatment for toilet wastewater only:
* Composting toilet (see also dry toilets in general)
* Urine-diverting dry toilet
* Vermifilter toilet | 1 | Applied and Interdisciplinary Chemistry |
Pol III is unusual (compared to Pol II) by requiring no control sequences upstream of the gene, instead normally relying on internal control sequences - sequences within the transcribed section of the gene (although upstream sequences are occasionally seen, e.g. U6 snRNA gene has an upstream TATA box as seen in Pol II Promoters).
There are three classes of Pol III initiation, corresponding to 5S rRNA, tRNA, and U6 snRNA initiation. In all cases, the process starts with transcription factors binding to control sequences and ends with TFIIIB (Transcription Factor for polymerase III B) being recruited to the complex and assembling Pol III. TFIIIB consists of three subunits: TATA binding protein (TBP), a TFIIB-related factor (BRF1, or BRF2 for transcription of a subset of Pol III-transcribed genes in vertebrates), and a B-double-prime (BDP1) unit. The overall architecture bears similarities to that of Pol II. | 1 | Applied and Interdisciplinary Chemistry |
In an effort to unify the above described equations the Mayr equation is rewritten as:
with s the electrophile-dependent slope parameter and s the nucleophile-dependent slope parameter. This equation can be rewritten in several ways:
* with s = 1 for carbocations this equation is equal to the original Mayr–Patz equation of 1994,
* with s = 0.6 for most n nucleophiles the equation becomes
:or the original Scott–Swain equation written as:
* with s = 1 for carbocations and s = 0.6 the equation becomes:
:or the original Ritchie equation written as: | 0 | Theoretical and Fundamental Chemistry |
Eurobachelor is a registered trademark and an initiative adopted by the EuCheMS General Assembly in 2003. It is associated with the Chemistry Quality Eurolabels. As of 8 April 2013, 60 Eurobachelor quality labels have been awarded. The label is intended for first cycle qualifications (bachelor's degrees).
Eurobachelor is based on 180 ECTS (European credits), which is comparable to the three-year British degrees, but it does not include the British concepts of honours degrees and ordinary degrees. | 1 | Applied and Interdisciplinary Chemistry |
Scientists Miquel Vila-Perello´, Matthew R. Pratt, Frej Tulin, and Tom W. Muir wanted to create an efficient synthesis as the original had required an enzymatic solution and had a low yield. So, they started with L-glutamic acid with protecting groups on both the carboxylic acid (tert-butyl), and Boc on the amine. This synthesis will not undergo detail as the classic, but below is the full synthesis. To find the actual steps, look to the reference.
So, once they had synthesized L-photo-methionine, the yield was 32%, much higher (by six times) the original synthesis. It was used then (with a protection group Fmoc on the amine) which that product underwent more synthetic steps to study if an amino-acid cross linker and a post-translational modification (PTM) could be introduced to the same protein site specifically to capture a covalent interaction of the amino-acid is dependent on the PTM. PTM's regulate protein-protein interactions that have characteristics that are transient and substoichiometric; making these difficult to detect by standard methods. So, in order to see if it would work, the MH2 domain of Smad2 was used because this signaling protein is known to form stable homo-trimers once they come into contact with receptor-phosphorylated serine residues. Expression protein ligation (known as EPL) was used to synthesize to form Smad2-MH2-CSpSM-photo-Met (1). The product was studied with the cross-linker (photo-Met) against a control protein: HA-MH2-CSpSMpS (this lacks photo-methionine, 2) using SDS-PAGE and western blotting using anti-HA antibody. 1 had generated two major cross-linked species that have molecular weight consistent with a dimer and trimer of Smad2-SH2. Without that cross-linker, the dimer and trimer were barely detected in the non-irradiated 1, and in 2 before and after UV irradiation. Proving that l-photo-methionine can be used with EPL and could be used to determine a transient MH2-MH2 interaction that was dependent on a PTM. | 0 | Theoretical and Fundamental Chemistry |
Figure 4 shows the phenyl rings that are used for β-agonists. They are named resorcinol ring, a salicyl alcohol or an m-formamide group. Figure 5 shows where different substituents on phenylethylamine take places marked as different R-groups. | 1 | Applied and Interdisciplinary Chemistry |
Five drugs in the class of NNRTIs have been approved by regulatory authorities. These are the first generation NNRTIs nevirapine, delavirdine and efavirenz and the next generation NNRTIs etravirine, and rilpivirine. Several other NNRTIs underwent clinical development but were discontinued due to unfavourable pharmacokinetic, efficacy and/or safety factors.
Currently there are four other NNRTIs undergoing clinical development, IDX899, RDEA-428 and lersivirine (table 2). | 1 | Applied and Interdisciplinary Chemistry |
The Reef Ball Foundation uses a pneumatic bladder technology to float an artificial coral reef ("reef ball") into location, then deflate the bladder to sink the reef to the bottom. | 1 | Applied and Interdisciplinary Chemistry |
Rotary vacuum drum filter (RVDF), patented in 1872, is one of the oldest filters used in the industrial liquid-solids separation. It offers a wide range of industrial processing flow sheets and provides a flexible application of dewatering, washing and/or clarification.
A rotary vacuum filter consists of a large rotating drum covered by a cloth. The drum is suspended on an axial over a trough containing liquid or solids slurry with approximately 50-80% of the screen area immersed in the slurry.
As the drum rotates into and out of the trough, the slurry is sucked on the surface of the cloth and rotated out of the liquid or solids suspension as a cake. When the cake is rotating out, it is dewatered in the drying zone. The cake is dry because the vacuum drum is continuously sucking the cake and taking the water out of it. At the final step of the separation, the cake is discharged as solids products and the drum rotates continuously to another separation cycle. | 0 | Theoretical and Fundamental Chemistry |
In addition to the filtered mass and momentum equations, filtering the kinetic energy equation can provide additional insight. The kinetic energy field can be filtered to yield the total filtered kinetic energy:
and the total filtered kinetic energy can be decomposed into two terms: the kinetic energy of the filtered velocity field ,
and the residual kinetic energy ,
such that .
The conservation equation for can be obtained by multiplying the filtered momentum transport equation by to yield:
where is the dissipation of kinetic energy of the filtered velocity field by viscous stress, and represents the sub-filter scale (SFS) dissipation of kinetic energy.
The terms on the left-hand side represent transport, and the terms on the right-hand side are sink terms that dissipate kinetic energy.
The SFS dissipation term is of particular interest, since it represents the transfer of energy from large resolved scales to small unresolved scales. On average, transfers energy from large to small scales. However, instantaneously can be positive or negative, meaning it can also act as a source term for , the kinetic energy of the filtered velocity field. The transfer of energy from unresolved to resolved scales is called backscatter (and likewise the transfer of energy from resolved to unresolved scales is called forward-scatter). | 1 | Applied and Interdisciplinary Chemistry |
Typhas and Phragmites are the main species used in constructed wetland due to their effectiveness, even though they can be invasive outside their native range.
In North America, cattails (Typha latifolia) are common in constructed wetlands because of their widespread abundance, ability to grow at different water depths, ease of transport and transplantation, and broad tolerance of water composition (including pH, salinity, dissolved oxygen and contaminant concentrations). Elsewhere, Common Reed (Phragmites australis) are common (both in blackwater treatment but also in greywater treatment systems to purify wastewater).
Plants are usually indigenous in that location for ecological reasons and optimum workings. | 1 | Applied and Interdisciplinary Chemistry |
In a molecule, both the electrons and nuclei experience similar-scale forces from the Coulomb interaction. However, the nuclei remain at nearly fixed locations in the molecule while the electrons move significantly. This picture of a molecule is based on the idea that nucleons are much heavier than electrons, so will move much less in response to the same force. Neutron scattering experiments on molecules have been used to verify this description. | 0 | Theoretical and Fundamental Chemistry |
A water distribution system is a part of water supply network with components that carry potable water from a centralized treatment plant or wells to consumers to satisfy residential, commercial, industrial and fire fighting requirements. | 1 | Applied and Interdisciplinary Chemistry |
Fatty acid degradation is the process in which fatty acids are broken down into their metabolites, in the end generating acetyl-CoA, the entry molecule for the citric acid cycle, the main energy supply of living organisms, including bacteria and animals. It includes three major steps:
* Lipolysis of and release from adipose tissue
* Activation and transport into mitochondria
* β-oxidation | 1 | Applied and Interdisciplinary Chemistry |
The coordinate of a normal vibration is a combination of changes in the positions of atoms in the molecule. When the vibration is excited the coordinate changes sinusoidally with a frequency , the frequency of the vibration. | 0 | Theoretical and Fundamental Chemistry |
In 1771 Benjamin Franklin was on a tour of Britain with Sir John Pringle who advised him to visit William Brownrigg. Franklin stayed at Brownriggs home of Ormathwaite in the Lake District and was presented with a signed copy of his book on salt. Franklin demonstrated his experiment of adding oil to the water surface of Derwent Water to calm the waves. He later corresponded with Brownrigg on the subject leading to another paper for The Royal Societys transactions. | 1 | Applied and Interdisciplinary Chemistry |
The flow cells are connected to a display and/or recorder. On older systems this was a simple chart recorder, on modern systems a computer with hardware interface and display is used. This permits the experimenter to identify when peaks in protein concentration occur, indicating that specific components of the mixture are being eluted. | 0 | Theoretical and Fundamental Chemistry |
Tantalum anodizes similarly to titanium and niobium with a range of attractive colours being formed by interference at different film thicknesses. Again the film thickness is dependent on the anodizing voltage and typically ranges from 18 to 23 Angstroms per volt depending on electrolyte and temperature. Uses include tantalum capacitors. | 1 | Applied and Interdisciplinary Chemistry |
Nuclear magnetic resonance is extremely useful for analyzing samples non-destructively. Radio-frequency magnetic fields easily penetrate many types of matter and anything that is not highly conductive or inherently ferromagnetic. For example, various expensive biological samples, such as nucleic acids, including RNA and DNA, or proteins, can be studied using nuclear magnetic resonance for weeks or months before using destructive biochemical experiments. This also makes nuclear magnetic resonance a good choice for analyzing dangerous samples. | 0 | Theoretical and Fundamental Chemistry |
In 1961, Israeli archaeologist Pessah Bar-Adon discovered a hoard of Chalcolithic artifacts in a cave on the northern side of Nahal Mishmar, known since as the Treasure Cave. The hoard consisted of 442 decorated objects made of copper and bronze (429 of them), ivory and stone, including 240 mace heads, about 100 scepters, 5 crowns, powder horns, tools and weapons. Archaeologist David Ussishkin has suggested the hoard was the cultic furniture of the abandoned Chalcolithic Temple of Ein Gedi. Prominent finds from the hoard are currently on display in the archaeology wing of the Israel Museum in Jerusalem.
Items in the hoard belong to the Ghassulian culture and the Nahal Mishmar hoard is the only hoard of this culture. It is probable that the copper used for producing them was mined in Wadi Feynan.
Due to the dry climate numerous textile and plaited remains were found at the site. The remains of over 20 individuals were found in the caves. They were members of a sedentary Chalcolithic population who became refugees and their lives ended under tragic circumstances which is indicated by the fact they had numerous injuries and that the wrappings were stained with blood.
Many of these copper objects were made using the lost-wax process, one of the earliest known uses of this complex technique. Carbon-14 dating of the reed mat which was used to wrap the objects points that it was used circa 3500 B.C.E. During this period the use of copper became widespread throughout the Levant which also led to social changes in the region. | 1 | Applied and Interdisciplinary Chemistry |
*BAT1 aka DDX39B
*HNRPD Homo sapiens heterogeneous nuclear ribonucleoprotein D (AU-rich element RNA
*HNRPK Homo sapiens heterogeneous nuclear ribonucleoprotein K (HNRPK), transcript
*PABPN1 poly(A) binding protein, nuclear 1
*SRSF3 splicing factor, arginine/serine-rich | 1 | Applied and Interdisciplinary Chemistry |
In China, the Ministry of Health and the Ministry of Agriculture have jointly established mechanisms and working procedures relating to maximum residue limit standards, while updating them continuously, according to the food safety law and regulations issued by the State Council. From GB25193-2010 to GB28260-2011, from Maximum Residue Limits for 12 Pesticides to 85 pesticides, they have improved the standards in response to Chinese national needs. | 1 | Applied and Interdisciplinary Chemistry |
In pharmacology and biochemistry, mode of action (MoA) describes a functional or anatomical change, resulting from the exposure of a living organism to a substance. In comparison, a mechanism of action (MOA) describes such changes at the molecular level.
A mode of action is important in classifying chemicals, as it represents an intermediate level of complexity in between molecular mechanisms and physiological outcomes, especially when the exact molecular target has not yet been elucidated or is subject to debate. A mechanism of action of a chemical could be "binding to DNA" while its broader mode of action would be "transcriptional regulation". However, there is no clear consensus and the term mode of action is also often used, especially in the study of pesticides, to describe molecular mechanisms such as action on specific nuclear receptors or enzymes. | 1 | Applied and Interdisciplinary Chemistry |
Calcineurin along with NFAT, may improve the function of diabetics' pancreatic beta cells. Thus tacrolimus contributes to the frequent development of new diabetes following renal transplantation.
Calcineurin/NFAT signaling is required for perinatal lung maturation and function. | 1 | Applied and Interdisciplinary Chemistry |
Wöhler investigated more than twenty‐five chemical elements during his career. Hans Christian Ørsted was the first to separate the element aluminium in 1825, using a reduction of aluminium chloride with a potassium amalgam. Although Ørsted published his findings on the isolation of aluminium in the form of small particles, no other investigators successfully replicated his findings until 1936. Ørsted is now credited with discovering aluminium. Ørsteds findings on aluminium preparation were developed further by Wöhler, with Ørsteds permission. Wöhler modified Ørsted's methods, substituting potassium metal for potassium amalgam for the reduction of aluminium chloride. Using this improved method, Wöhler isolated aluminium powder in pure form on 22 October 1827. He showed that the aluminium powder could convert to solid balls of pure metallic aluminium in 1845. For this work, Wöhler is credited with the first isolation of aluminium in pure form.
In 1828 Wöhler was the first to isolate the element beryllium in pure metallic form (also independently isolated by Antoine Bussy). In the same year, he became the first to isolate the element yttrium in pure metallic form. He achieved these preparations by heating the anhydrous chlorides of beryllium and yttrium with potassium metal.
In 1850, Wöhler determined that what was believed until then to be metallic titanium was a mixture of titanium, carbon, and nitrogen, from which he derived the purest form isolated to that time. (Elemental titanium was later isolated in completely pure form in 1910 by Matthew A. Hunter.) He also developed a chemical synthesis of calcium carbide and silicon nitride.
Wöhler, working with French chemist Sainte Claire Deville, isolated the element boron in a crystalline form. He also isolated the element silicon in a crystalline form. Crystalline forms of these two elements were previously unknown. In 1856, working with Heinrich Buff, Wöhler prepared the inorganic compound silane (SiH). He prepared the first samples of boron nitride by melting together boric acid and potassium cyanide. He also developed a method for the preparation of calcium carbide.
Wöhler had an interest in the chemical composition of meteorites. He showed that some meteoric stones contain organic matter. He analyzed meteorites, and for many years wrote the digest on the literature of meteorites in the Jahresberichte über die Fortschritte der Chemie. Wöhler accumulated the best private collection of meteoric stones and irons that existed. | 1 | Applied and Interdisciplinary Chemistry |
Flucloxacillin is used for both staphylococcal and streptococcal skin infections. These include folliculitis, carbuncles, impetigo, ecthyma, cellulitis, erysipelas, necrotising fasciitis, and infections of skin conditions such as eczema, scabies, ulcers and acne. Due to the widespread belief that dual-therapy is needed to cover both Staphylococcus and Streptococcus in cellulitis, flucloxacillin is sometimes given with the addition of benzylpenicillin for more severe cellulitis. However, support for this practice has lessened since findings in a study published in the Emergency Medicine Journal in 2005 did not show this combination to give additional clinical benefit. In the UK, using flucloxacillin alone is the first choice for treating cellulitis. Some other countries vary. | 0 | Theoretical and Fundamental Chemistry |
The dominant industrial method for producing ammonia is the Haber process also known as the Haber-Bosch process. Fertilizer production is now the largest source of human-produced fixed nitrogen in the terrestrial ecosystem. Ammonia is a required precursor to fertilizers, explosives, and other products. The Haber process requires high pressures (around 200 atm) and high temperatures (at least 400 °C), which are routine conditions for industrial catalysis. This process uses natural gas as a hydrogen source and air as a nitrogen source. The ammonia product has resulted in an intensification of nitrogen fertilizer globally and is credited with supporting the expansion of the human population from around 2 billion in the early 20th century to roughly 8 billion people now. | 1 | Applied and Interdisciplinary Chemistry |
Since the early 1970s, TOC has been an analytic technique used to measure water quality during the drinking water purification process. TOC in source waters comes from decaying natural organic matter (NOM) as well as synthetic sources. Humic acid, fulvic acid, amines, and urea are examples of NOM. Some detergents, pesticides, fertilizers, herbicides, industrial chemicals, and chlorinated organics are examples of synthetic sources. Before source water is treated for disinfection, TOC provides an estimate of the amount of NOM in the water source. In water treatment facilities, source water is subject to reaction with chlorine-containing disinfectants. When the raw water is chlorinated, active chlorine compounds (Cl, HOCl, ClO) react with NOM to produce chlorinated disinfection byproducts (DBPs). Researchers have determined that higher levels of NOM in source water during the disinfection process will increase the amount of carcinogens in the processed drinking water.
With passage of the U.S. Safe Drinking Water Act in 2001, TOC analysis emerged as a quick and accurate alternative to the classical but more lengthy biological oxygen demand (BOD) and chemical oxygen demand (COD) tests traditionally reserved for assessing the pollution potential of wastewaters. Today, environmental agencies regulate the trace limits of DBPs in drinking water. Recently published analytical methods, such as United States Environmental Protection Agency (EPA) method 415.3, support the Agencys Disinfectants and Disinfection Byproducts Rules,' which regulate the amount of NOM to prevent the formation of DBPs in finished waters.
The content of TOC is also an important parameter to evaluate the quality of organic shale resources which are one of the most important unconventional fuels. Numerous evaluation methods have been introduced, including these based on wireline logs and in situ techniques. | 0 | Theoretical and Fundamental Chemistry |
The MeDIP-seq approach, i.e. the coupling of MeDIP with next generation, short-read sequencing technologies such as 454 pyrosequencing or Illumina (Solexa), was first described by Down et al. in 2008. The high-throughput sequencing of the methylated DNA fragments produces a large number of short reads (36-50bp or 400 bp, depending on the technology). The short reads are aligned to a reference genome using alignment software such as Mapping and Assembly with Quality ([http://maq.sf.net Maq]), which uses a Bayesian approach, along with base and mapping qualities to model error probabilities for the alignments. The reads can then be extended to represent the ~400 to 700 bp fragments from the sonication step. The coverage of these extended reads can be used to estimate the methylation level of the region. A genome browser such as [http://www.ensembl.org Ensembl] can also be used to visualize the data.
Validation of the approach to assess quality and accuracy of the data can be done with quantitative PCR. This is done by comparing a sequence from the MeDIP sample against an unmethylated control sequence. The samples are then run on a gel and the band intensities are compared. The relative intensity serves as the guide for finding enrichment. The results can also be compared with MeDIP-chip results to help determine coverage needed. | 1 | Applied and Interdisciplinary Chemistry |
The Arnold–Beltrami–Childress (ABC) flow or Gromeka–Arnold–Beltrami–Childress (GABC) flow is a three-dimensional incompressible velocity field which is an exact solution of Euler's equation. Its representation in Cartesian coordinates is the following:
where is the material derivative of the Lagrangian motion of a fluid parcel located at
It is notable as a simple example of a fluid flow that can have chaotic trajectories.
It is named after Vladimir Arnold, Eugenio Beltrami, and Stephen Childress. Ippolit S. Gromeka's (1881) name has been historically neglected, though much of the discussion has been done by him first. | 1 | Applied and Interdisciplinary Chemistry |
There are an overwhelming number of mathematical models which are referred to as Boussinesq equations. This may easily lead to confusion, since often they are loosely referenced to as the Boussinesq equations, while in fact a variant thereof is considered. So it is more appropriate to call them Boussinesq-type equations. Strictly speaking, the Boussinesq equations is the above-mentioned set B, since it is used in the analysis in the remainder of his 1872 paper.
Some directions, into which the Boussinesq equations have been extended, are:
*varying bathymetry,
*improved frequency dispersion,
*improved non-linear behavior,
*making a Taylor expansion around different vertical elevations,
*dividing the fluid domain in layers, and applying the Boussinesq approximation in each layer separately,
*inclusion of wave breaking,
*inclusion of surface tension,
*extension to internal waves on an interface between fluid domains of different mass density,
*derivation from a variational principle. | 1 | Applied and Interdisciplinary Chemistry |
The process involves transesterification of sucrose and triglycerides under a basic condition at 90 °C. DMF was used as a solvent at first, but was later substituted with dimethyl sulfoxide or DMSO, which is less hazardous and cheaper. This process produces a mixture of sucrose monoesters and more substituted esters at about a 5:1 ratio.
The other method involves transesterification of sucrose and fatty acid methyl ester using sodium methoxide as a basic catalyst. The by-product methanol can be removed via distillation to drive the equilibrium to favor sucrose esters.
The process does not work for food industry because DMF is poisonous and may not be used in food production. | 0 | Theoretical and Fundamental Chemistry |
Very little change was seen from the decline of the Roman Empire until the 19th century, where improvements saw increasing efforts focused on public health. Modern environmental engineering began in London in the mid-19th century when Joseph Bazalgette designed the first major sewerage system following the Great Stink. The citys sewer system conveyed raw sewage to the River Thames, which also supplied the majority of the citys drinking water, leading to an outbreak of cholera. The introduction of drinking water treatment and sewage treatment in industrialized countries reduced waterborne diseases from leading causes of death to rarities.
The field emerged as a separate academic discipline during the middle of the 20th century in response to widespread public concern about water and air pollution and other environmental degradation. As society and technology grew more complex, they increasingly produced unintended effects on the natural environment. One example is the widespread application of the pesticide DDT to control agricultural pests in the years following World War II. The story of DDT as vividly told in Rachel Carsons Silent Spring' (1962) is considered to be the birth of the modern environmental movement, which led to the modern field of "environmental engineering." | 1 | Applied and Interdisciplinary Chemistry |
Everhardus Jacobus Ariëns (29 January 1918 – 3 March 2002) was a Dutch pharmacologist and professor at the Catholic University of Nijmegen (now Radboud University Nijmegen). He made important contributions to the function of receptors and the mathematical description of ligand–receptor interactions (receptor theory). Moreover, Everhardus Ariëns was a pioneer of the consideration of stereochemistry in drug development, such as the development of enantiopure drugs. | 0 | Theoretical and Fundamental Chemistry |
As well as the electronic transitions discussed above, the energy of a molecule can also change via rotational, vibrational, and vibronic (combined vibrational and electronic) transitions. These energy transitions often lead to closely spaced groups of many different spectral lines, known as spectral bands. Unresolved band spectra may appear as a spectral continuum. | 0 | Theoretical and Fundamental Chemistry |
For a compressible fluid, with a barotropic equation of state, and under the action of conservative forces,
where:
* is the pressure
* is the density and indicates that it is a function of pressure
* is the flow speed
* is the potential associated with the conservative force field, often the gravitational potential
In engineering situations, elevations are generally small compared to the size of the Earth, and the time scales of fluid flow are small enough to consider the equation of state as adiabatic. In this case, the above equation for an ideal gas becomes:
where, in addition to the terms listed above:
* is the ratio of the specific heats of the fluid
* is the acceleration due to gravity
* is the elevation of the point above a reference plane
In many applications of compressible flow, changes in elevation are negligible compared to the other terms, so the term can be omitted. A very useful form of the equation is then:
where:
* is the total pressure
* is the total density | 1 | Applied and Interdisciplinary Chemistry |
ChIP-exo is a chromatin immunoprecipitation based method for mapping the locations at which a protein of interest (transcription factor) binds to the genome. It is a modification of the ChIP-seq protocol, improving the resolution of binding sites from hundreds of base pairs to almost one base pair. It employs the use of exonucleases to degrade strands of the protein-bound DNA in the 5-3 direction to within a small number of nucleotides of the protein binding site. The nucleotides of the exonuclease-treated ends are determined using some combination of DNA sequencing, microarrays, and PCR. These sequences are then mapped to the genome to identify the locations on the genome at which the protein binds.
__TOC__ | 1 | Applied and Interdisciplinary Chemistry |
If muon-catalyzed d–t nuclear fusion is realized practically, it will be a much more attractive way of generating power than conventional nuclear fission reactors because muon-catalyzed d–t nuclear fusion (like most other types of nuclear fusion), produces far fewer harmful (and far less long-lived) radioactive wastes.
The large number of neutrons produced in muon-catalyzed d–t nuclear fusions may be used to breed fissile fuels from fertile material – for example, thorium-232 could breed uranium-233 in this way. The fissile fuels that have been bred can then be "burned," either in a conventional critical nuclear fission reactor or in an unconventional subcritical fission reactor, for example, a reactor using nuclear transmutation to process nuclear waste, or a reactor using the energy amplifier concept devised by Carlo Rubbia and others.
Another benefit of muon-catalyzed fusion is that the fusion process can start with pure deuterium gas without tritium. Plasma fusion reactors like ITER or Wendelstein X7 need tritium to initiate and also need a tritium factory. Muon-catalyzed fusion generates tritium under operation and increases operating efficiency up to an optimum point when the deuterium:tritium ratio reaches about 1:1. Muon-catalyzed fusion can operate as a tritium factory and deliver tritium for material and plasma fusion research. | 0 | Theoretical and Fundamental Chemistry |
Crabtree has made significant contributions to the field of carbene chemistry, particularly in the exploration of mesoionic carbenes (MICs), or so called "abnormal carbenes". These carbenes, offer advantages as ligand systems in organometallic complexes and catalytic applications. Unlike C2 coordinated imidazolylidenes, mesoionic carbenes possess only charge-separated electronic resonance structures, allowing for greater adaptability to metal centers within catalytic cycles. Crabtree has developed novel methods for generating and isolating abnormal carbenes, providing insights into their structures and stability under different conditions. Notably, he introduced the first example of an abnormal carbene complex incorporating an iridium complex with a C4 coordinated imidazolylidene, which found application in transfer hydrogenation catalysis. | 0 | Theoretical and Fundamental Chemistry |
Thiocyanate shares its negative charge approximately equally between sulfur and nitrogen. Thiocyanate can bind metals at either sulfur or nitrogen — it is an ambidentate ligand. Other factors, e.g. kinetics and solubility, sometimes influence the observed isomer. For example, [Co(NH)(NCS)] is the thermodynamic isomer, but [Co(NH)(SCN)] forms as the kinetic product of the reaction of thiocyanate salts with [Co(NH)(HO)].
Some complexes of SCN feature both but only thiocyanate and isothiocyanate ligands. Examples are found for heavy metals in the middle of the d-period: Ir(III), and Re(IV). | 0 | Theoretical and Fundamental Chemistry |
Neoantigens are those that are entirely absent from the normal human genome. As compared with nonmutated self-proteins, neoantigens are of relevance to tumor control, as the quality of the T cell pool that is available for these antigens is not affected by central T cell tolerance. Technology to systematically analyze T cell reactivity against neoantigens became available only recently. Neoantigens can be directly detected and quantified. | 1 | Applied and Interdisciplinary Chemistry |
A Master of Chemistry (or MChem) degree is a specific master's degree for courses in the field of Chemistry. | 1 | Applied and Interdisciplinary Chemistry |
Nucleophilic abstraction can occur on a ligand of a metal if the conditions are right. For instance the following example shows the nucleophilic abstraction of H from an arene ligand attached to chromium. The electron withdrawing nature of the chromium allows for the reaction to occur as a [http://en.wiktionary.org/wiki/facile facile] reaction. | 0 | Theoretical and Fundamental Chemistry |
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