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All ETS (Erythroblast Transformation Specific) family members are identified through a highly conserved DNA binding domain, the ETS domain, which is a winged helix-turn-helix structure that binds to DNA sites with a central GGA(A/T) DNA sequence. As well as DNA-binding functions, evidence suggests that the ETS domain is also involved in protein-protein interactions.
There is limited similarity outside the ETS DNA binding domain.
Other domains are also present and vary from ETS member to ETS member, including the Pointed domain, a subclass of the SAM domain family. | 1 | Applied and Interdisciplinary Chemistry |
The molecule can only exist in an excited state. The different excited electronic states are represented by symbols for the outer electron nLΓ with n the principal quantum number, L is the electronic angular momentum, and Γ is the electronic symmetry selected from the D group. Extra bracketed symbols can be attached showing vibration in the core: {s,d} with s representing symmetrical stretch, d degenerate mode, and l vibrational angular momentum. Yet another term can be inserted to indicate molecular rotation: (N,G) with N angular momentum apart from electrons as projected on the molecular axis, and G the Hougens convenient quantum number determined by G=l+λ-K. This is often (1,0), as the rotational states are restricted by the constituent particles all being fermions. Examples of these states are: 2sA 3sA 2pA" 3dE 3DE" 3dA 3pE 3pA". The 2pA" state has a lifetime of 700 ns. If the molecule attempts to lose energy and go to the repulsive ground state, it spontaneously breaks up. The lowest energy metastable state, 2sA has an energy -3.777 eV below the and e state but decays in around 1 ps. The unstable ground state designated 2pE spontaneously breaks up into a H molecule and an H atom. Rotationless states have a longer life time than rotating molecules.
The electronic state for a trihydrogen cation with an electron delocalized around it is a Rydberg state.
The outer electron can be boosted to high Rydberg state, and can ionise if the energy gets to 29562.6 cm above the 2pA" state, in which case forms. | 0 | Theoretical and Fundamental Chemistry |
A durable plaster intermediate is often used as a stage toward the production of a bronze sculpture or as a pointing guide for the creation of a carved stone. With the completion of a plaster, the work is more durable (if stored indoors) than a clay original which must be kept moist to avoid cracking. With the low cost plaster at hand, the expensive work of bronze casting or stone carving may be deferred until a patron is found, and as such work is considered to be a technical, rather than artistic process, it may even be deferred beyond the lifetime of the artist.
In waste molding a simple and thin plaster mold, reinforced by sisal or burlap, is cast over the original clay mixture. When cured, it is then removed from the damp clay, incidentally destroying the fine details in undercuts present in the clay, but which are now captured in the mold. The mold may then at any later time (but only once) be used to cast a plaster positive image, identical to the original clay. The surface of this plaster may be further refined and may be painted and waxed to resemble a finished bronze casting. | 1 | Applied and Interdisciplinary Chemistry |
Neurotransmitter release can be measured by determining the amplitude of the postsynaptic potential after triggering an action potential in the presynaptic neuron. Measuring neurotransmitter release this way can be problematic because the effect of the postsynaptic neuron to the same amount of released neurotransmitter can change over time. Another way is to measure vesicle fusion with the presynaptic membrane directly using a patch pipette. A cell membrane can be thought of as a capacitor in that positive and negative ions are stored on both sides of the membrane. The larger the area of membrane the more ions that are necessary to hold the membrane at a certain potential. In electrophysiology this means that a current injection into the terminal will take less time to charge a membrane to a given potential before vesicle fusion than it will after vesicle fusion. The time course to charge the membrane to a potential and the resistance of the membrane is measured and with these values the capacitance of the membrane can be calculated by the equation Tau/Resistance=Capacitance. With this technique researchers can measure synaptic vesicle release directly by measuring increases in the membrane capacitance of the presynaptic terminal. | 1 | Applied and Interdisciplinary Chemistry |
Lichenometry is a technique used to determine the age of exposed rock surfaces based on the size of lichen thalli. Introduced by Beschel in the 1950s, the technique has found many applications. it is used in archaeology, palaeontology, and geomorphology. It uses the presumed regular but slow rate of lichen growth to determine the age of exposed rock. Measuring the diameter (or other size measurement) of the largest lichen of a species on a rock surface indicates the length of time since the rock surface was first exposed. Lichen can be preserved on old rock faces for up to 10,000 years, providing the maximum age limit of the technique, though it is most accurate (within 10% error) when applied to surfaces that have been exposed for less than 1,000 years. Lichenometry is especially useful for dating surfaces less than 500 years old, as radiocarbon dating techniques are less accurate over this period. The lichens most commonly used for lichenometry are those of the genera Rhizocarpon (e.g. the species Rhizocarpon geographicum, map lichen) and Xanthoria. | 1 | Applied and Interdisciplinary Chemistry |
George Charles de Hevesy (born György Bischitz; ; ; 1 August 1885 – 5 July 1966) was a Hungarian radiochemist and Nobel Prize in Chemistry laureate, recognized in 1943 for his key role in the development of radioactive tracers to study chemical processes such as in the metabolism of animals. He also co-discovered the element hafnium. | 1 | Applied and Interdisciplinary Chemistry |
Anti-Scl-70 antibodies are linked to scleroderma. The sensitivity of the antibodies for scleroderma is approximately 34%, but is higher for cases with diffuse cutaneous involvement (40%), and lower for limited cutaneous involvement (10%). The specificity of the antibodies is 98% and 99.6% in other rheumatic diseases and normal individuals, respectively. In addition to scleroderma, these antibodies are found in approximately 5% of individuals with SLE. The antigenic target of anti-Scl-70 antibodies is topoisomerase I. | 1 | Applied and Interdisciplinary Chemistry |
Using multi-spectral imaging it is possible to read illegible papyrus, such as the burned papyri of the Villa of the Papyri or of Oxyrhynchus, or the Archimedes palimpsest. The technique involves taking pictures of the illegible document using different filters in the infrared or ultraviolet range, finely tuned to capture certain wavelengths of light. Thus, the optimum spectral portion can be found for distinguishing ink from paper on the papyrus surface.
Simple NUV sources can be used to highlight faded iron-based ink on vellum. | 0 | Theoretical and Fundamental Chemistry |
Oxygen fugacities during metamorphism extend to higher values than those in magmatic environments, because of the more oxidizing compositions inherited from some sedimentary rocks. Nearly pure hematite is present in some metamorphosed banded iron formations. In contrast, native nickel-iron is present in some serpentinites. | 0 | Theoretical and Fundamental Chemistry |
Human as well murine STAT4 genes lie next to STAT1 gene locus suggesting that the genes arose by gene duplication. STAT proteins have six functional domains: 1. N-terminal interaction domain – crucial for dimerization of inactive STATs and nuclear translocation; 2.helical coiled coil domain – association with regulatory factors; 3. central DNA-binding domain – binding to the enhancer region of IFN-γ activated sequence (GAS) family genes; 4. linker domain – assisting during the DNA binding process; 5. Src homology 2 (SH2) domain – critical for specific binding to the cytokine receptor after tyrosine phosphorylation; 6. C-terminal transactivation domain – triggering the transcriptional process. The length of the protein is 748 amino acids, and the molecular weight is 85 941 Dalton. | 1 | Applied and Interdisciplinary Chemistry |
* Platyhelminthes (flatworms) and Nematoda (roundworms).
Code 14 differs from code 9 (the echinoderm and flatworm mitochondrial code) only by translating UAA to Tyr rather than STOP. A study in 2000 has found no evidence that the codon UAA codes for Tyr in the flatworms but other opinions exist. There are very few GenBank records that are translated with code 14 but a test translation shows that re-translating these records with code 9 can cause premature terminations. More recently, UAA has been found to code for tyrosine in the nematodes Radopholus similis and Radopholus arabocoffeae. | 1 | Applied and Interdisciplinary Chemistry |
The compound is prepared by the addition of ammonium salts to solutions of vanadate ions, generated by dissolution of VO in basic aqueous solutions, such as hot sodium carbonate. The compound precipitates as a colourless solid. This precipitation step can be slow.
The compound adopts a polymeric structure consisting of chains of [VO], formed as corner-sharing VO tetrahedra. These chains are interconnected via hydrogen bonds with ammonium ions. | 0 | Theoretical and Fundamental Chemistry |
It is possible to synthesize COFs using both dynamic covalent and non-covalent chemistry. The kinetic approach involves a stepwise process of polymerizing pre-assembled 2D-monomer while thermodynamic control exploits reversible covalent chemistry to allow simultaneous monomer assembly and polymerization. Under thermodynamic control, bond formation and crystallization also occur simultaneously. Covalent organic frameworks formed by dynamic covalent bond formation involves chemical reactions carried out reversibly under conditions of equilibrium control. Because the formation of COFs in dynamic covalent formation occurs under thermodynamic control, product distributions depend only on the relative stabilities of the final products. Covalent assembly to form 2D COFs has been previously done using boronate esters from catechol acetonides in the presence of a lewis acid (BF*OEt).
2D polymerization under kinetic control relies on non-covalent interactions and monomer assembly prior to bond formation. The monomers can be held together in a pre-organized position by non-covalent interactions, such as hydrogen bonding or van der Waals. | 0 | Theoretical and Fundamental Chemistry |
Quantum information science developed in the latter decades of the 20th century, beginning with theoretical results like Holevos theorem, the concept of generalized measurements or POVMs, the proposal of quantum key distribution by Bennett and Brassard, and Shors algorithm. | 1 | Applied and Interdisciplinary Chemistry |
In chemistry, an ate complex is a salt formed by the reaction of a Lewis acid with a Lewis base whereby the central atom (from the Lewis acid) increases its valence and gains a negative formal charge. (In this definition, the meaning of valence is equivalent to coordination number).
Often in chemical nomenclature the term ate is suffixed to the element in question. For example, the ate complex of a boron compound is called a borate. Thus trimethylborane and methyllithium react to form the ate compound , lithium tetramethylborate(1-). This concept was introduced by Georg Wittig in 1958. Ate complexes are common for metals, including the transition metals (groups 3-11), as well as the metallic or semi-metallic elements of group 2, 12, and 13. They are also well-established for third-period or heavier elements of groups 14–18 in their higher oxidation states.
Ate complexes are a counterpart to onium ions.
Lewis acids form ate ions when the central atom reacts with a donor ( X-type ligand), gaining one more bond and becoming a negative-charged anion.
Lewis bases form onium ions when the central atom reacts with an acceptor ( Z-type ligand), gaining one more bond and becoming a positive-charged cation. | 0 | Theoretical and Fundamental Chemistry |
A redox titration is a type of titration based on a redox reaction between the analyte and titrant. It may involve the use of a redox indicator and/or a potentiometer. A common example of a redox titration is treating a solution of iodine with a reducing agent to produce iodide using a starch indicator to help detect the endpoint. Iodine (I) can be reduced to iodide (I) by, say, thiosulfate (), and when all iodine is spent the blue colour disappears. This is called an iodometric titration.
Most often of all, the reduction of iodine to iodide is the last step in a series of reactions where the initial reactions are used to convert an unknown amount of the solute (the substance being analyzed) to an equivalent amount of iodine, which may then be titrated. Sometimes other halogens (or haloalkanes) than iodine are used in the intermediate reactions because they are available in better measurable standard solutions and/or react more readily with the solute. The extra steps in iodometric titration may be worthwhile because the equivalence point, where the blue turns a bit colourless, is more distinct than some other analytical or may be by volumetric methods.
The main redox titration types are: | 0 | Theoretical and Fundamental Chemistry |
Exogenous retroviruses are infectious RNA- or DNA-containing viruses that are transmitted from one organism to another. In the Baltimore classification system, which groups viruses together based on their manner of messenger RNA synthesis, they are classified into two groups: Group VI: single-stranded RNA viruses with a DNA intermediate in their life cycle, and Group VII: double-stranded DNA viruses with an RNA intermediate in their life cycle. | 1 | Applied and Interdisciplinary Chemistry |
The Oddo–Harkins rule holds that an element with an even atomic number is more abundant than the elements with immediately adjacent atomic numbers. For example, carbon, with atomic number 6, is more abundant than boron (5) and nitrogen (7). Generally, the relative abundance of an even atomic numbered element is roughly two orders of magnitude greater than the relative abundances of the immediately adjacent odd atomic numbered elements to either side. This pattern was first reported by Giuseppe Oddo in 1914 and William Draper Harkins in 1917. The Oddo-Harkins rule is true for all elements beginning with carbon produced by stellar nucleosynthesis but not true for the lightest elements below carbon produced by big bang nucleosynthesis and cosmic ray spallation. | 0 | Theoretical and Fundamental Chemistry |
PbSnSe/PbSrSe quantum well materials, which can be grown by MBE on silicon substrates, have been proposed for low cost TPV device fabrication. These IV-VI semiconductor materials can have bandgaps between 0.3 and 0.6 eV. Their symmetric band structure and lack of valence band degeneracy result in low Auger recombination rates, typically more than an order of magnitude smaller than those of comparable bandgap III-V semiconductor materials. | 0 | Theoretical and Fundamental Chemistry |
In a single solute solution, the (molality based) osmotic coefficient and the solute activity coefficient are related to the excess Gibbs free energy by the relations:
and there is thus a differential relationship between them (temperature and pressure held constant): | 0 | Theoretical and Fundamental Chemistry |
The flow area of each caisson should be maximised. This can be achieved by:
* Ensuring the greatest possible distance between the caisson walls, with steel diagonals providing sufficient torsional stiffness.
* Designing the bottom of the caissons to be as thin as possible.
* Incorporating ballast spaces within the superstructure of the caisson to add necessary weight, thereby generating sufficient friction between the caisson and the sill. | 1 | Applied and Interdisciplinary Chemistry |
DC slice imaging is a developed version of traditional velocity map imaging technique which was developed in Suits group. In DC slicing, the ion cloud is allowed to expand by a weaker field in the ionization region. By this the arrival time is expanded to several hundred ns. By a fast transistor switch, one is able to select the central part of the ion cloud (Newton sphere). This central slice has the full velocity and angular distribution. A reconstruction by mathematical methods is not necessary. (D. Townsend, S. K. Lee and A. G. Suits, “Orbital polarization from DC slice imaging: S(1D) alignment in the photodissociation of ethylene sulfide,” Chem. Phys., 301, 197 (2004).) | 0 | Theoretical and Fundamental Chemistry |
While the anomeric effect is a general explanation for this type of stabilization for a molecule, the type and amount of stabilization can be affected by the substituents being examined as well as the solvent being studied. | 0 | Theoretical and Fundamental Chemistry |
The Reststrahlen effect is used to investigate the properties of semiconductors, it is also used in geophysics and meteorology. | 0 | Theoretical and Fundamental Chemistry |
On-line Questions are being uploaded again after the Summer School. All students-even the directly connected ones-have to take this test to become the final representatives. Second grade students in the high school take this test. This test is counted 20 percent when KCS chooses the final representatives of South Korea. In this test, most of the questions are related to Organic Chemistry. 15 students directly connected from the Summer School 2 and 15 students who got a good score in the Test 4 can join the Winter School 2. | 1 | Applied and Interdisciplinary Chemistry |
In organic chemistry, the vicarious nucleophilic substitution is a special type of nucleophilic aromatic substitution in which a nucleophile replaces a hydrogen atom on the aromatic ring and not leaving groups such as halogen substituents which are ordinarily encountered in SAr. This reaction type was reviewed in 1987 by Polish chemists Mieczysław Mąkosza and Jerzy Winiarski.
It is typically encountered with nitroarenes and especially with nucleophiles, resulting in alkylated arenes: the new substituent can take the ortho or para positions, reversing the selectivity for the meta position that is usually observed with such compounds under electrophilic substitution. Carbon nucleophiles carry an electron-withdrawing group and a leaving group: the nucleophile attacks the aromatic ring, and excess base can eliminate to form an exocyclic double bond which is successively protonated under acidic conditions, restoring aromaticity. | 0 | Theoretical and Fundamental Chemistry |
Extrusion is executed by mixing the powder with liquid, additives, or dispersants and then compressing the mixture and forcing it through a die. The product is then dried and broken down to the desired particle size. Extruded powders are dense. Extrusion is typically used for ingredients such as minerals and highly-hygroscopic products which benefit from reduced surface area, as well as products that are subject to oxidation. Extrusion for agglomeration should not be confused with the more common food extrusion process that involves creating a dough that is cooked and expands as it passes through the die. | 1 | Applied and Interdisciplinary Chemistry |
The use of progesterone tests in dog breeding to pinpoint ovulation is becoming more widely used. There are several tests available but the most reliable test is a blood test with blood drawn by a veterinarian and sent to a lab for processing. Results can usually be obtained with 24 to 72 hours. The rationale for using progesterone tests is that increased numbers begin in close proximity to preovulatory surge in gonadotrophins and continue through ovulation and estrus. When progesterone levels reach certain levels they can signal the stage of estrus the female is. Prediction of birth date of the pending litter can be very accurate if ovulation date is known. Puppies deliver with a day or two of 9 weeks gestation in most cases. It is not possible to determine pregnancy using progesterone tests once a breeding has taken place, however. This is due to the fact that, in dogs, progesterone levels remain elevated throughout the estrus period. | 0 | Theoretical and Fundamental Chemistry |
The commercialization of passive daytime radiative cooling technologies is in an early stage of development.
SkyCool Systems, founded by Aaswath P. Raman, who authored the scientific breakthrough study demonstrating the use of photonic metamaterials in making PDRC possible, is a startup that is commercializing radiative cooling technologies. SkyCool panels have been applied to some buildings in California, reducing energy costs. The company has received a grant from the California Energy Commission for further application opportunities.
3M, an American multinational corporation, has developed a selectively emissive passive radiative cooling film. The film has been applied through pilot programs that are open for expansion. The film was tested on bus shelters in Tempe, Arizona. 3Ms film achieved "10–20% energy savings when deployed on SkyCool Systems panels and integrated with a buildings HVAC or refrigeration system."
[https://www.rl-cool.com/#/about Radi-Cool], co-founded by [https://scholar.google.com/citations?user=O47HWggAAAAJ&hl=zh-CN Prof. Yin] and [https://scholar.google.com/citations?user=rLiK2VIAAAAJ&hl=zh-CN Prof. Yang], who achieved the large-scale production and application of the zero-consumption radiative cooling technology in China. Radi-Cool products have been applied in many areas such like airport (Singapore, [https://haneda-airport-business.com/en/radicool.html Japan]), office building and big mall (Philippines, Malaysia), warehouse industrial (Germany, Latin America), etc. They have grown rapidly and have expanded the distribution all over the world. Their film and coating can help the world to reduce the carbon dioxide emission and create an eco-friendly environment. [https://coldrays.com Coldrays], an Arizona-based startup founded in July of 2023, is the first United States distributor of Radi-Cool products. They supply Radi-Cool products for commercial and industrial application in the American Southwest. | 0 | Theoretical and Fundamental Chemistry |
For what concern the Samburu-Buffalo Springs, five weeks after the rainy season had started, the grass became rich in nutrients and the females were most likely to conceive, giving birth 22 months later, just in time for another rainy season to provide nutrients to the grass they would have eaten: the cycle could restart.
The research also pointed out how developed is the competition between elephants and cattle: during the typical wet season diet of elephants, the overgrazing by cattle caused the grass to be very short, resulting in a limited access to it for elephants, out-competing them. This situation could have influenced the elephants' ability to bulk up for pregnancy. | 0 | Theoretical and Fundamental Chemistry |
Sodium trifluoroacetate as a reagent for trifluoromethylations was introduced by Matsui in 1981. In the original scope the substrate was an aromatic halide and the metal salt copper(I)iodide. | 0 | Theoretical and Fundamental Chemistry |
Multiple bacterial strains have been metabolically engineered to increase the individual yields of end products formed by mixed acid fermentation. For instance, strains for the increased production of ethanol, lactate, succinate and acetate have been developed due to the usefulness of these products in biotechnology.
The major limiting factor for this engineering is the need to maintain a redox balance in the mixture of acids produced by the fermentation pathway. | 1 | Applied and Interdisciplinary Chemistry |
In low-dimensional systems, for example in dye-solution filled optical microcavities with a distance between the resonator mirrors in the wavelength range where the situation becomes two-dimensional, also photon gases with tunable chemical potential can been realized. Such a photon gas in many respects behaves like a gas of material particles. One consequence of the tunable chemical potential is that at high phase space densities then Bose-Einstein condensation of photons is observed. | 0 | Theoretical and Fundamental Chemistry |
Founded in 2003 and formerly headquartered in East Norriton Township, Pennsylvania before moving to Winston-Salem, North Carolina in 2012, Tengion went public in 2010, after its stock has been approved for listing on the NASDAQ, through a $26 million IPO to help advance its research and development activities. Some of the groundbreaking regenerative medicine technologies of Dr. Anthony Atala, director of the Wake Forest Institute for Regenerative Medicine, were the core from where those research and development activities developed.
On September 4, 2012, Tengion received a notice from NASDAQ stating that the company had not regained compliance with NASDAQ Listing Rule 5550(b)(1) and that its common stock would cease trading on the NASDAQ Capital Market effective on September 6, 2012, and would begin trading on the OTCQB tier of the OTC Marketplace. The company was bought by former executives and creditors after declaring bankruptcy in 2014. | 1 | Applied and Interdisciplinary Chemistry |
Schiff bases have been investigated in relation to a wide range of contexts, including antimicrobial, antiviral and anticancer activity. They have also been considered for the inhibition of amyloid-β aggregation.
Schiff bases are common enzymatic intermediates where an amine, such as the terminal group of a lysine residue, reversibly reacts with an aldehyde or ketone of a cofactor or substrate. The common enzyme cofactor pyridoxal phosphate (PLP) forms a Schiff base with a lysine residue and is transaldiminated to the substrate(s). Similarly, the cofactor retinal forms a Schiff base in rhodopsins, including human rhodopsin (via Lysine 296), which is key in the photoreception mechanism. | 0 | Theoretical and Fundamental Chemistry |
Retinoic acids tretinoin (all-trans-retinoic acid) and isotretinoin (13-cis-retinoic acid) are prescription topical medications used to treat moderate to severe cystic acne and acne not responsive to other treatments. These are usually applied as a skin cream to the face after cleansing to remove make-up and skin oils. Tretinoin and isotretinoin act by binding to two nuclear receptor families within keratinocytes: the retinoic acid receptors (RAR) and the retinoid X receptors (RXR). These events contribute to the normalization of follicular keratinization and decreased cohesiveness of keratinocytes, resulting in reduced follicular occlusion and microcomedone formation. The retinoid-receptor complex competes for coactivator proteins of AP-1, a key transcription factor involved in inflammation. Retinoic acid products also reduce sebum secretion, a nutrient source for bacteria, from facial pores.
These drugs are US-designated Pregnancy Category C (animal reproduction studies have shown an adverse effect on the fetus), and should not be used by pregnant women or women who are anticipating becoming pregnant. Many countries established a physician- and patient- education pregnancy prevention policy.
Trifarotene is a prescription retinoid for the topical treatment acne vulgaris. It functions as a retinoic acid receptor (RAR)-γ agonist.
Non-prescription topical products that have health claims for reducing facial acne, combating skin dark spots and reducing wrinkles and lines associated with aging often contain retinyl palmitate. The hypothesis is that this is absorbed and desterified to free retinol, then converted to retinaldehyde and further metabolized to all-trans-retinoic acid, whence it will have the same effects as prescription products with fewer side effects. There is some ex vivo evidence with human skin that esterified retinol is absorbed and then converted to retinol. In addition to esterified retinol, some of these products contain hydroxypinacolone retinoate, identified as esterified 9-cis-retinoic acid. | 1 | Applied and Interdisciplinary Chemistry |
Current U.S. assay offices include the following:
* The Philadelphia Mint – 1792 to date
* The Denver Mint – 1862 to date. It served as an assay office until 1906, when coinage operations began.
* The San Francisco Mint – 1852 to date. Coinage operations were suspended in March 1955, but the plant continued to operate as an assay office. In 1962, its official designation was changed from mint to assay office. Coinage operations were again authorized in 1965.
* The West Point, New York Bullion Depository – 1938 to date. It is operated as an adjunct of the New York Assay Office. | 0 | Theoretical and Fundamental Chemistry |
India receives about 4,000 cubic kilometers of rain annually, or about 1 million gallons of fresh water per person every year. However, the precipitation pattern in India varies dramatically across distance and over calendar months. Much of the precipitation in India, about 85%, is received during summer months through monsoons in the Himalayan catchments of the Ganges-Brahmaputra-Meghna (GBM) basin. The northeastern region of the country receives heavy precipitation, in comparison with the northwestern, western and southern parts. The uncertainty of the start date of the monsoons, sometimes marked by prolonged dry spells and fluctuations in seasonal and annual rainfall is a serious problem for the country. The nation sees cycles of drought years and flood years, with large parts of the west and south experiencing more deficits and large variations, resulting in immense hardship, particularly for the poorest farmers and rural populations. Lack of irrigation water regionally leads to crop failures and farmer suicides. Despite abundant rains during July–September, some regions in other seasons see shortages of drinking water. Some years, the problem temporarily becomes too much rainfall and weeks of havoc from floods. This excess-scarcity, regional disparity and flood-drought cycles have created the need for water resources management. Rivers inter-linking is one proposal to address that need. Due to global warming, fossil fuels use is discouraged and carbon neutral, clean, and renewable energy sources like solar and wind power are encouraged which are intermittent and variable types of electricity generation. Pumped storage hydroelectric power plants are needed to store the surplus electricity generated during daylight time by the solar power plants and supply the required electricity during the night hours. Water security, energy security, and food security can be achieved by interlinking rivers by envisaging multipurpose freshwater coastal reservoirs. | 1 | Applied and Interdisciplinary Chemistry |
A genetically modified organism (GMO) is any organism whose genetic material has been altered using genetic engineering techniques. The exact definition of a genetically modified organism and what constitutes genetic engineering varies, with the most common being an organism altered in a way that "does not occur naturally by mating and/or natural recombination". A wide variety of organisms have been genetically modified (GM), including animals, plants, and microorganisms.
Genetic modification can include the introduction of new genes or enhancing, altering, or knocking out endogenous genes. In some genetic modifications, genes are transferred within the same species, across species (creating transgenic organisms), and even across kingdoms. Creating a genetically modified organism is a multi-step process. Genetic engineers must isolate the gene they wish to insert into the host organism and combine it with other genetic elements, including a promoter and terminator region and often a selectable marker. A number of techniques are available for inserting the isolated gene into the host genome. Recent advancements using genome editing techniques, notably CRISPR, have made the production of GMOs much simpler. Herbert Boyer and Stanley Cohen made the first genetically modified organism in 1973, a bacterium resistant to the antibiotic kanamycin. The first genetically modified animal, a mouse, was created in 1974 by Rudolf Jaenisch, and the first plant was produced in 1983. In 1994, the Flavr Savr tomato was released, the first commercialized genetically modified food. The first genetically modified animal to be commercialized was the GloFish (2003) and the first genetically modified animal to be approved for food use was the AquAdvantage salmon in 2015.
Bacteria are the easiest organisms to engineer and have been used for research, food production, industrial protein purification (including drugs), agriculture, and art. There is potential to use them for environmental purposes or as medicine. Fungi have been engineered with much the same goals. Viruses play an important role as vectors for inserting genetic information into other organisms. This use is especially relevant to human gene therapy. There are proposals to remove the virulent genes from viruses to create vaccines. Plants have been engineered for scientific research, to create new colors in plants, deliver vaccines, and to create enhanced crops. Genetically modified crops are publicly the most controversial GMOs, in spite of having the most human health and environmental benefits. Animals are generally much harder to transform and the vast majority are still at the research stage. Mammals are the best model organisms for humans. Livestock is modified with the intention of improving economically important traits such as growth rate, quality of meat, milk composition, disease resistance, and survival. Genetically modified fish are used for scientific research, as pets, and as a food source. Genetic engineering has been proposed as a way to control mosquitos, a vector for many deadly diseases. Although human gene therapy is still relatively new, it has been used to treat genetic disorders such as severe combined immunodeficiency and Leber's congenital amaurosis.
Many objections have been raised over the development of GMOs, particularly their commercialization. Many of these involve GM crops and whether food produced from them is safe and what impact growing them will have on the environment. Other concerns are the objectivity and rigor of regulatory authorities, contamination of non-genetically modified food, control of the food supply, patenting of life, and the use of intellectual property rights. Although there is a scientific consensus that currently available food derived from GM crops poses no greater risk to human health than conventional food, GM food safety is a leading issue with critics. Gene flow, impact on non-target organisms, and escape are the major environmental concerns. Countries have adopted regulatory measures to deal with these concerns. There are differences in the regulation for the release of GMOs between countries, with some of the most marked differences occurring between the US and Europe. Key issues concerning regulators include whether GM food should be labeled and the status of gene-edited organisms. | 1 | Applied and Interdisciplinary Chemistry |
In positive plant-insect interactions, GLVs are used as a form of defense. They attract predators to plants that are being preyed upon by herbivores.
For example, female parasitoid wasps from two different families, Microplitis croceipes and Netelia heroica, can be attracted to plants that are emitting GLVs due to wounding from caterpillars. Maize plants emit volatiles to attract the parasitic wasps Cotesia marginiventris and Microplitis rufiventris to attack African cotton leafworm. In some species GLVs enhance the attraction of sex pheromones. For example, green leaf volatiles have been found to increase the response of tobacco budworm to sex pheromone. Budworm larvae feed on tobacco, cotton, and various flowers and weeds, and in turn can be fed on by the larvae of cohabiting species that are attracted by GLVs.
In another study, a multi-plant relationship was reported. The parasitic wasps (Vespula germanica and V. vulgaris) prey on caterpillar (Pieris brassicae)-infested cabbage leaves that emit GLVs. The same GLVs are emitted by the orchids (Epipactis purpurata and E. helleborine) through pheromone release. The orchids benefit from attracting the wasps, not to protect them from insects, but because the wasps aid in pollination.
Benefits of GLV release have also been reported in soybeans grown in Iowa. When these soybean plants became heavily infested by aphids, the amount of GLV released far surpassed normal levels and as a result, more spotted lady beetles were attracted to the pheromone releasing plants and preyed on the bugs eating the plant. The stimulus of aphid predation is chemically transmitted through the plant to coordinate an increase release of GLV’s. The particular chemical released is unique to these spotted lady beetles and when different species of beetles were tested, there wasn’t any extra inclination for them to move towards GLV releasing plants. This indicates that these soybeans evolved ability to release species-specific pheromones to aid in their survival. | 1 | Applied and Interdisciplinary Chemistry |
Engineering professions emerge when new technologies, new problems or new opportunities arise. This was the case when safety engineering grew in the early 1900s to combat the high workplace injury and fatality rates. In the 1960s, Environmental engineering emerged as a discipline to reduce industrial pollution and mitigate impacts on environmental health and water quality. Quality engineering came about with the increase in mass production techniques during WWII and the need to confirm the quality of the products. When engineered systems must change, either due to failure risks, obsolescence or modernisation, change management is a well-known process. Transition Engineering is focused on identifying the unsustainable aspects of currently operational engineered systems, innovating the projects that down-shift the unsustainable energy, material, environmental and social aspects, and then carrying out an inclusive change management process.
There are two serious problems driving the emergence of Transition Engineering; the exponential growth in the concentration of carbon dioxide in Earth’s atmosphere and the lack of growth and imminent decline of conventional oil production sometimes characterised as peak oil. The concentration of carbon dioxide in the atmosphere ran past the "climate safe" 350 ppm range in the 1990s, and has now exceeded 420ppm, a level that Earth has not known for 800,000 years. Transition engineering aims to take advantage of the current access to the remaining lower cost and higher EROI energy resources to re-develop all aspects of urban and industrial engineered systems to adapt as fossil fuel use is dramatically reduced. | 1 | Applied and Interdisciplinary Chemistry |
Contract research organizations (CROs) provide services to the life science industries along product development. There are more than 2000 CROs operating worldwide, representing revenues of more than $20 billion. One distinguishes between "Product" and "Patient" CROs. Whereas the production sites of CMOs are multipurpose plants, allowing for the production of tens to hundreds of tons of fine chemicals, the work places of patient CROs are the test persons (volunteers) for the clinical trials and those of the product CROs are the laboratory benches. Major customers for CRO services are the large global pharmaceutical companies. Half a dozen companies (Pfizer, GlaxoSmithKline, Sanofi-Aventis, AstraZeneca, Johnson & Johnson, and Merck & Co.) alone absorb about one third of all CRO spending. As for CMOs also for CROs, biotech start-up companies with their dichotomy between ambitious drug development programs and limited resources are the second most promising prospects. Product CROs (chemical CROs) are providing primarily sample preparation, process research and development services. An overlap between the latter and CMOs exists with regard to pilot plants (100 kg quantities), which are part of the arsenal of both types of enterprise.
There are more 100 product CROs. Most of them are privately held and have revenues of $10–$20 million per year or less, adding up to a total business in the range of $1.5-$2 billion. Their tasks are described in Chapter 5,
Examples of are:
*In North America: Alphora; Delmar; NAEJA, all Canada. AMRI; Aptuit; Cambridge Major; ChemBridge; Innocentive; Irix Pharmaceuticals, PharmEco, all USA.
*In Europe; Carbogen-Amcis, Switzerland; Chemcomm, Germany; ChemDiv, Russia; Clauson-Kaas, Denmark; Enamine Ltd, Ukraine; Girindus, Germany; Nerviano Medical Sciences, Italy; Recipharm, Sweden; Serichim, Italy; Solvias, Switzerland, Netherlands.
*In Asia: BioDuro, Medicilon, Pharmaron; WuXi AppTec, all China; Acoris; Aptuit Laurus; Biocon / Syngene; Chembiotek; Chempartner; ProCitius, all India; NARD Institute, Riken, both Japan.
The business of CROs is usually done through a "pay for service" arrangement. Contrary to manufacturing companies, invoicing of CROs is not based on unit product price, but on full-time equivalents (FTEs), that is, the cost of a scientist working one year on a given customer assignment.
Companies offering both contract research and manufacturing services (CRAMS) combine the activities of CROs and CMOs. Their history is either a forward integration of a CRO, which adds industrial scale capabilities or backwards integration of a CMO. As there are only limited synergies (e.g. > 90% of the projects end at the sample preparation stage). It is questionable, though, whether one-stop shops really fulfil a need. Actually, the large fine chemical companies consider the preparation of samples more as marketing tool (and expense ...) rather than a profit contributor.
The offerings of Patient CROs (Clinical CROs) comprise more than 30 tasks addressing the clinical part of pharmaceutical development at the interface between drugs, physicians, hospitals, and patients, such as the clinical development and selection of lead new drug compounds. As clinical trials represent the largest expense in pharmaceutical research, the market for patient CROs is larger than for their product counterparts. Thus, the sales of the top tier firms, Charles River Laboratories, Covance, Parexel, PPD, Quintiles Transnational, all USA, and TCG Lifescience, India; are in the $1–$2 billion range, whereas the largest product CROs have revenues of a few 100 million dollars. | 0 | Theoretical and Fundamental Chemistry |
Although less commonly used, activation energy also applies to nuclear reactions and various other physical phenomena. | 0 | Theoretical and Fundamental Chemistry |
The brief existence of an mRNA molecule begins with transcription, and ultimately ends in degradation. During its life, an mRNA molecule may also be processed, edited, and transported prior to translation. Eukaryotic mRNA molecules often require extensive processing and transport, while prokaryotic mRNA molecules do not. A molecule of eukaryotic mRNA and the proteins surrounding it are together called a messenger RNP. | 1 | Applied and Interdisciplinary Chemistry |
In chemistry, a half reaction (or half-cell reaction) is either the oxidation or reduction reaction component of a redox reaction. A half reaction is obtained by considering the change in oxidation states of individual substances involved in the redox reaction.
Often, the concept of half reactions is used to describe what occurs in an electrochemical cell, such as a Galvanic cell battery. Half reactions can be written to describe both the metal undergoing oxidation (known as the anode) and the metal undergoing reduction (known as the cathode).
Half reactions are often used as a method of balancing redox reactions. For oxidation-reduction reactions in acidic conditions, after balancing the atoms and oxidation numbers, one will need to add ions to balance the hydrogen ions in the half reaction. For oxidation-reduction reactions in basic conditions, after balancing the atoms and oxidation numbers, first treat it as an acidic solution and then add ions to balance the ions in the half reactions (which would give ). | 0 | Theoretical and Fundamental Chemistry |
In open channel flows, introduced first the ratio of the flow velocity to the square root of the gravity acceleration times the flow depth. When the ratio was less than unity, the flow behaved like a fluvial motion (i.e., subcritical flow), and like a torrential flow motion when the ratio was greater than unity.
Quantifying resistance of floating objects is generally credited to William Froude, who used a series of scale models to measure the resistance each model offered when towed at a given speed. The naval constructor Frederic Reech had put forward the concept much earlier in 1852 for testing ships and propellers but Froude was unaware of it. Speed–length ratio was originally defined by Froude in his Law of Comparison in 1868 in dimensional terms as:
where:
* = flow speed
* = length of waterline
The term was converted into non-dimensional terms and was given Froude's name in recognition of the work he did. In France, it is sometimes called Reech–Froude number after Frederic Reech. | 1 | Applied and Interdisciplinary Chemistry |
Homosynaptic plasticity (or also homotropic modulation) is a change in the synaptic strength that results from the history of activity at a particular synapse. This can result from changes in presynaptic calcium as well as feedback onto presynaptic receptors, i.e. a form of autocrine signaling. Homosynaptic plasticity can affect the number and replenishment rate of vesicles or it can affect the relationship between calcium and vesicle release. Homosynaptic plasticity can also be postsynaptic in nature. It can result in either an increase or decrease in synaptic strength.
One example is neurons of the sympathetic nervous system (SNS), which release noradrenaline, which, besides affecting postsynaptic receptors, also affects presynaptic α2-adrenergic receptors, inhibiting further release of noradrenaline. This effect is utilized with clonidine to perform inhibitory effects on the SNS. | 1 | Applied and Interdisciplinary Chemistry |
It is prepared in the laboratory by disproportionation of phosphorous acid:
Alternative methods are the hydrolysis of tris(trimethylsilyl)phosphine, or of metal phosphides such as aluminium phosphide, or calcium phosphide:
Pure samples of phosphine, free from , may be prepared using the action of potassium hydroxide on phosphonium iodide: | 0 | Theoretical and Fundamental Chemistry |
The backbone and side-chain dihedral angles of protein and RNA have been shown to have specific combinations of angles which are allowed (or forbidden). For protein backbone dihedrals (φ, ψ), this has been addressed by the legendary Ramachandran Plot while for side-chain dihedrals (χ's), one should refer to the Dunbrack Backbone-dependent rotamer library.
Though, mRNA structures are generally short-lived and single-stranded, there are an abundance of non-coding RNAs with different secondary and tertiary folding (tRNA, rRNA etc.) which contain a preponderance of the canonical Watson-Crick (WC) base-pairs, together with significant number of non-Watson Crick (NWC) base-pairs - for which such RNA also qualify for regular structural validation that apply for nucleic acid helices. The standard practice is to analyse the intra- (Transnational: Shift, Slide, Rise; Rotational: Tilt, Roll, Twist) and inter-base-pair geometrical parameters (Transnational: Shear, Stagger, Stretch, Rotational: Buckle, Propeller, Opening) - whether in-range or out-of-range with respect to their suggested values. These parameters describe the relative orientations of the two paired bases with respect to each other in two strands (intra) along with those of the two stacked base pairs (inter) with respect to each other, and, hence, together, they serve to validate nucleic acid structures in general. Since, RNA-helices are small in length (average: 10-20 bps), the use of electrostatic surface potential as a validation parameter has been found to be beneficial, particularly for modelling purposes. | 1 | Applied and Interdisciplinary Chemistry |
Most species have a negligible vapour pressure at such low temperatures, and this means that they quickly condense on the sides of the apparatus. Essentially, the CRESU technique provides a "wall-less flow tube", which allows the kinetics of gas-phase reactions to be investigated at much lower temperatures than otherwise possible.
Chemical kinetics experiments can then be carried out in a pump–probe fashion, using a laser to initiate the reaction (for example, by preparing one of the reagents by photolysis of a precursor), followed by observation of that same species (for example, by laser-induced fluorescence) after a known time delay. The fluorescence signal is captured by a photomultiplier a known distance downstream of the de Laval nozzle. The time delay can be varied up to the maximum corresponding to the flow time over that known distance. By studying how quickly the reagent species disappears in the presence of differing concentrations of a (usually stable) co-reagent species, the reaction rate constant at the low temperature of the CRESU flow can be determined.
Reactions studied by the CRESU technique typically have no significant activation energy barrier. In the case of neutral–neutral reactions (i.e., not involving any charged species, ions), these type of barrier-free reactions usually involve free radical species, such as molecular oxygen (O), the cyanide radical (CN) or the hydroxyl radical (OH). The energetic driving force for these reactions is typically an attractive long-range intermolecular potential.
CRESU experiments have been used to show deviations from Arrhenius kinetics at low temperatures: as the temperature is reduced, the rate constant actually increases. They can explain why chemistry is so prevalent in the interstellar medium, where many different polyatomic species have been detected (by radio astronomy). | 0 | Theoretical and Fundamental Chemistry |
Operando spectroscopy is a class of methodology, rather than a specific spectroscopic technique such as FTIR or NMR. Operando spectroscopy is a logical technological progression in in situ studies. Catalyst scientists would ideally like to have a "motion picture" of each catalytic cycle, whereby the precise bond-making or bond-breaking events taking place at the active site are known; this would allow a visual model of the mechanism to be constructed. The ultimate goal is to determine the structure-activity relationship of the substrate-catalyst species of the same reaction. Having two experiments—the performing of a reaction plus the real-time spectral acquisition of the reaction mixture—on a single reaction facilitates a direct link between the structures of the catalyst and intermediates, and of the catalytic activity/selectivity. Although monitoring a catalytic process in situ can provide information relevant to catalytic function, it is difficult to establish a perfect correlation because of the current physical limitations of in situ reactor cells. Complications arise, for example, for gas phase reactions which require large void volumes, which make it difficult to homogenize heat and mass within the cell. The crux of a successful operando methodology, therefore, is related to the disparity between laboratory setups and industrial setups, i.e., the limitations of properly simulating the catalytic system as it proceeds in industry.
The purpose of operando spectroscopy is to measure the catalytic changes that occur within the reactor during operation using time-resolved (and sometimes spatially-resolved) spectroscopy. Time-resolved spectroscopy theoretically monitor the formation and disappearance of intermediate species at the active site of the catalyst as bond are made and broken in real time. However, current operando instrumentation often only works in the second or subsecond time scale and therefore, only relative concentrations of intermediates can be assessed. Spatially resolved spectroscopy combines spectroscopy with microscopy to determine active sites of the catalyst studied and spectator species present in the reaction. | 0 | Theoretical and Fundamental Chemistry |
MG (pyrimido[1,2-a]purin-10(3H)-one) is a heterocyclic compound which is a by-product of base excision repair (BER) of a specific type of DNA adduct called MdG. The MdG adduct in turn is formed by a condensation reaction between guanosine nucleotides in DNA and either malondialdehyde (propanedial) or acrolein. If not repaired, these adducts are mutagenic and carcinogenic.
Malondialdehyde is an end product of lipid peroxidation while acrolein is a result of DNA peroxidation.
MdG is the major endogenous DNA adduct in humans. MdG adducts have been detected in cell DNA in liver, leucocytes, pancreas and breast in concentrations of 1-120 per 10 nucleotides. Detection and quantification of MdG adducts in the body as measured by free MG is a tool for detecting DNA damage that may lead to cancer. Free MG is also biomarker for oxidative stress. | 1 | Applied and Interdisciplinary Chemistry |
Robert Howard Crabtree studied at Brighton College (1959–1966), and earned a Bachelor of Arts degree from the University of Oxford where he was a student at New College, Oxford in 1970, studying under Malcolm Green. He received his PhD from the University of Sussex in 1973, supervised by Joseph Chatt. | 0 | Theoretical and Fundamental Chemistry |
Continuing and expanding the tradition of the University of Athens within the subject, starting from Zervas of Bergmann-Zervas carbobenzoxy method fame, Photaki initially worked on further refinement of suitable protecting groups for oligopeptide synthesis. She investigated with Zervas new types of protection such as N-protection with benzyl phosphate esters (N-phosphamide derivatives), S-protection using trityl, benzhydryl or benzoyl groups (as part of the greater effort for the synthesis of asymmetric cysteine-containing peptides), N-protection using the o-nitrophenylsulfenyl (NPS) group discovered in their Athens laboratory, or S-protection using the p-methoxycarbobenzoxy group (a modification of the Z group).
With the above methodologies she embarked on the synthesis of complex polypeptides, especially fragments of enzyme active sites and peptide hormones. Some notable achievements in papers Photaki co-authored include the first synthesis of the 20-membered insulin intra-chain ring or –following her research under du Vigneaud– several previously inaccessible oxytocin analogues (e.g. 4-deamido-oxytocin) and a novel oxytocin synthesis via a different route than the du Vigneaud synthesis.
In later years she also examined the preparation of biologically active atypical peptides such as N-arginine or lanthionine-containing peptides. | 0 | Theoretical and Fundamental Chemistry |
In polymer chemistry photo-oxidation (sometimes: oxidative photodegradation) is the degradation of a polymer surface due to the combined action of light and oxygen. It is the most significant factor in the weathering of plastics. Photo-oxidation causes the polymer chains to break (chain scission), resulting in the material becoming increasingly brittle. This leads to mechanical failure and, at an advanced stage, the formation of microplastics. In textiles the process is called phototendering.
Technologies have been developed to both accelerate and inhibit this process. For example, plastic building components like doors, window frames and gutters are expected to last for decades, requiring the use of advanced UV-polymer stabilizers. Conversely, single-use plastics can be treated with biodegradable additives to accelerate their fragmentation.
Many pigments and dyes can similarly have effects due to their ability to absorb UV-energy. | 0 | Theoretical and Fundamental Chemistry |
If the particles in the suspension are not neutrally buoyant, then the additional effect of settling also takes place. Pudasaini (2011) used the above constitutive relations to establish a scaling law for the sedimentation time. It is found analytically that the macro-viscous fluid settles much faster than the grain-inertia fluid, as manifested by dispersive pressure.
Given the same time, the macroviscous fluid is settled 6/5 unit length compared to the unit length settlement of the grain-inertia fluid as measured from the nose-tip of the flowfront that has already settled to the back side of the debris. Therefore, the macroviscous fluid settles (completely stops to flow) 20% faster than the grain-inertia fluid. Due to the dispersive pressure in grain-inertia fluid, the settlement process is delayed by 20% for the grain-inertia fluid than for the macroviscous fluid. This is meaningful because particles are more agitated due to higher dispersive pressure in grain-inertia fluids than in macroviscous fluids. Once the material comes close to rest, these dispersive forces (induced by the quadratic shear rate), are still active for grain-inertia fluid but macroviscous fluid settles relatively faster because it is less dispersive. This provides a tool to approximate and estimate the final settlement time (the time at which the entire fluid body is at rest). These are mechanically important relationships concerning the settlement time and the settlement lengths between the grain-inertia and the macroviscous fluids. | 1 | Applied and Interdisciplinary Chemistry |
Progesterone plays a role in early human sexual differentiation. Placental progesterone is the feedstock for the 5α-dihydrotestosterone (DHT) produced via the backdoor pathway found operating in multiple non-gonadal tissues of the fetus, whereas deficiencies in this pathway lead to undervirilization of the male fetus, resulting in incomplete development of the male genitalia. DHT is a potent androgen that is responsible for the development of male genitalia, including the penis and scrotum.
During early fetal development, the undifferentiated gonads can develop into either testes or ovaries. The presence of the Y chromosome leads to the development of testes. The testes then produce testosterone, which is converted to DHT via the enzyme 5α-reductase. DHT is a potent androgen that is responsible for the masculinization of the external genitalia and the development of the prostate gland. Progesterone, produced by the placenta during pregnancy, plays a role in fetal sexual differentiation by serving as a precursor molecule for the synthesis of DHT via the backdoor pathway. In the absence of adequate levels of steroidogenic enzymes during fetal development, the backdoor pathway for DHT synthesis can become deficient, leading to undermasculinization of the male fetus. This can result in the development of ambiguous genitalia or even female genitalia in some cases. Therefore, both DHT and progesterone play crucial roles in early fetal sexual differentiation, with progesterone acting as a precursor molecule for DHT synthesis and DHT promoting the development of male genitalia. | 0 | Theoretical and Fundamental Chemistry |
Sedimentary records are influenced by local topography and oceanic and atmospheric currents. Proxies of global climatic significance are, however, less ambiguous in paleotemperature interpretation. Marine biota have offered by far the most proxies for paleotemperature, of which the microfossils, because of their widespread, abundance and sensitive to latitudinal changes, have provided many primary important paleotemperature indicators. Identification of latitudinal indices species is usually the first attempt to tie their presence in sediments to paleotemperature fluctuations. Other properties of marine biota, including morphology, abundance, diversity, and geochemistry have also been successfully established as paleoclimate indicators. More complex statistical analyses (factor analysis, principal component, etc.) of biogeography have been able to link fauna assemblages to water masses for paleo-current reconstruction. List below are some key paleontological tools utilized by scientists to reconstruct paleotemperature history. | 0 | Theoretical and Fundamental Chemistry |
In some bacteria, the enzyme is regulated at the transcriptional level. It has been demonstrated that the gene for SCS (sucCD) is transcribed along with the gene for α-ketoglutarate dehydrogenase (sucAB) under the control of a promoter called sdhC, which is part of the succinate dehydrogenase operon. This operon is up-regulated by the presence of oxygen and responds to a variety of carbon sources. Antibacterial drugs that prevent phosphorylation of histidine, like the molecule LY26650, are potent inhibitors of bacterial SCSs. | 1 | Applied and Interdisciplinary Chemistry |
Desymmetrization in stereochemistry is the modification of a molecule that results in the loss of one or more symmetry elements. A common application of this class of reactions involves the introduction of chirality. Formally, such conversions required the loss of an improper axis of rotation (mirror plane, center of inversion, rotation-reflection axis). In other words, desymmetrisations convert prochiral precursors into chiral products. | 0 | Theoretical and Fundamental Chemistry |
Because the fluorescent secondary molecule is applied after capture of the free receptor from solution (Figure 2) the binding constants measured using a kinetic exclusion assay are for unmodified molecules in solution and thus more accurately reflects endogenous binding interactions than methods requiring modification (typically labeling or immobilization) before measurement. Kinetic exclusion assays have been performed using unpurified molecules, in serum, and have measured binding to cell membrane proteins on intact whole cell which brings the measured binding interactions closer to their endogenous state.
Molecules suited for measurement by KinExA are antibodies, recombinant proteins, small molecules, aptamers, lipids, nanobodies, and toxins.
Kinetic exclusion assay have also been applied for concentration immunoassay, where it has proven capable of providing the maximum theoretical, K limited, sensitivity. An example of this technique has been employed for sensitive detection of environmental contaminants i<nowiki/>n near real-time. | 1 | Applied and Interdisciplinary Chemistry |
A tablet (also known as a pill) is a pharmaceutical oral dosage form (oral solid dosage, or OSD) or solid unit dosage form. Tablets may be defined as the solid unit dosage form of medication with suitable excipients. It comprises a mixture of active substances and excipients, usually in powder form, that are pressed or compacted into a solid dose. The main advantages of tablets are that they ensure a consistent dose of medicine that is easy to consume.
Tablets are prepared either by moulding or by compression. The excipients can include diluents, binders or granulating agents, glidants (flow aids) and lubricants to ensure efficient tabletting; disintegrants to promote tablet break-up in the digestive tract; sweeteners or flavours to enhance taste; and pigments to make the tablets visually attractive or aid in visual identification of an unknown tablet. A polymer coating is often applied to make the tablet smoother and easier to swallow, to control the release rate of the active ingredient, to make it more resistant to the environment (extending its shelf life), or to enhance the tablet's appearance.
Medicinal tablets were originally made in the shape of a disk of whatever colour their components determined, but are now made in many shapes and colours to help distinguish different medicines. Tablets are often imprinted with symbols, letters, and numbers, which allow them to be identified, or a groove to allow splitting by hand. Sizes of tablets to be swallowed range from a few millimetres to about a centimetre.
The compressed tablet is the most commonly seen dosage form in use today. About two-thirds of all prescriptions are dispensed as solid dosage forms, and half of these are compressed tablets. A tablet can be formulated to deliver an accurate dosage to a specific site in the body; it is usually taken orally, but can be administered sublingually, buccally, rectally or intravaginally. The tablet is just one of the many forms that an oral drug can take such as syrups, elixirs, suspensions, and emulsions. | 1 | Applied and Interdisciplinary Chemistry |
The grand potential is related to the number of particles at finite temperature in the following way
where the derivative is taken at fixed temperature and volume, and it appears
also known as the Fermi–Dirac distribution.
Similarly, the total internal energy is | 0 | Theoretical and Fundamental Chemistry |
The inversion of ammonia was first detected by microwave spectroscopy in 1934.
In one study the inversion in an aziridine was slowed by a factor of 50 by placing the nitrogen atom in the vicinity of a phenolic alcohol group compared to the oxidized hydroquinone.
The system interconverts by oxidation by oxygen and reduction by sodium dithionite. | 0 | Theoretical and Fundamental Chemistry |
The excited nitrogen deexcites primarily by emission of a photon, with emission lines in ultraviolet, visible, and infrared band:
:N → N + hν
The blue light observed is produced primarily by this process. The spectrum is dominated by lines of single-ionized nitrogen, with presence of neutral nitrogen lines. | 0 | Theoretical and Fundamental Chemistry |
Hexamethylenetetramine or hexamine is also used as a food additive as a preservative (INS number 239). It is approved for usage for this purpose in the EU, where it is listed under E number E239, however it is not approved in the USA, Russia, Australia, or New Zealand. | 0 | Theoretical and Fundamental Chemistry |
Precipitation in hydrometallurgy involves the chemical precipitation from aqueous solutions, either of metals and their compounds or of the contaminants. Precipitation will proceed when, through reagent addition, evaporation, pH change or temperature manipulation, the amount of a species present in the solution exceeds the maximum determined by its solubility. | 1 | Applied and Interdisciplinary Chemistry |
* Dynamic Nuclear Polarization: New Experimental and Methodology Approaches and Applications in Physics, Chemistry, Biology and Medicine, Appl. Magn. Reson., 2008. 34(3–4)
* High field dynamic nuclear polarization – the renaissance, Phys. Chem. Chem. Phys., 2010. 12(22) | 0 | Theoretical and Fundamental Chemistry |
In chemical and biological defense, activated carbon is impregnated with DABCO for use in filters for masks, collective protection systems, and the like. | 0 | Theoretical and Fundamental Chemistry |
;Homoblasty: Characteristic in which a plant has small changes in leaf size, shape, and growth habit between juvenile and adult stages, in contrast to;
;Heteroblasty: Characteristic in which a plant has marked changes in leaf size, shape, and growth habit between juvenile and adult stages. | 0 | Theoretical and Fundamental Chemistry |
The fundamental pharmacophore for all adrenergic agonists is a substituted phenethylamine which increases the duration of action. | 1 | Applied and Interdisciplinary Chemistry |
Gunpowder is the first explosive to have been developed. Popularly listed as one of the "Four Great Inventions" of China, it was invented during the late Tang dynasty (9th century) while the earliest recorded chemical formula for gunpowder dates to the Song dynasty (11th century). Knowledge of gunpowder spread rapidly throughout Asia and Europe, possibly as a result of the Mongol conquests during the 13th century, with written formulas for it appearing in the Middle East between 1240 and 1280 in a treatise by Hasan al-Rammah, and in Europe by 1267 in the by Roger Bacon. It was employed in warfare to some effect from at least the 10th century in weapons such as fire arrows, bombs, and the fire lance before the appearance of the gun in the 13th century. While the fire lance was eventually supplanted by the gun, other gunpowder weapons such as rockets and fire arrows continued to see use in China, Korea, India, and this eventually led to its use in the Middle East, Europe, and Africa. Bombs too never ceased to develop and continued to progress into the modern day as grenades, mines, and other explosive implements. Gunpowder has also been used for non-military purposes such as fireworks for entertainment, or in explosives for mining and tunneling.
The evolution of guns led to the development of large artillery pieces, popularly known as bombards, during the 15th century, pioneered by states such as the Duchy of Burgundy. Firearms came to dominate early modern warfare in Europe by the 17th century. The gradual improvement of cannons firing heavier rounds for a greater impact against fortifications led to the invention of the star fort and the bastion in the Western world, where traditional city walls and castles were no longer suitable for defense. The use of gunpowder technology also spread throughout the Islamic world and to India, Korea, and Japan. The so-called Gunpowder Empires of the early modern period consisted of the Mughal Empire, Safavid Empire, and Ottoman Empire.
The use of gunpowder in warfare during the course of the 19th century diminished due to the invention of smokeless powder. Gunpowder is often referred to today as "black powder" to distinguish it from the propellant used in contemporary firearms. | 1 | Applied and Interdisciplinary Chemistry |
If a compound has more than one chiral stereocenter, each center is denoted by either R or S. For example, ephedrine exists in (1R,2S) and (1S,2R) stereoisomers, which are distinct mirror-image forms of each other, making them enantiomers. This compound also exists as the two enantiomers written (1R,2R) and (1S,2S), which are named pseudoephedrine rather than ephedrine. All four of these isomers are named 2-methylamino-1-phenyl-1-propanol in systematic nomenclature. However, ephedrine and pseudoephedrine are diastereomers, or stereoisomers that are not enantiomers because they are not related as mirror-image copies. Pseudoephedrine and ephedrine are given different names because, as diastereomers, they have different chemical properties, even for racemic mixtures of each.
More generally, for any pair of enantiomers, all of the descriptors are opposite: (R,R) and (S,S) are enantiomers, as are (R,S) and (S,R). Diastereomers have at least one descriptor in common; for example (R,S) and (R,R) are diastereomers, as are (S,R) and (S,S). This holds true also for compounds having more than two stereocenters: if two stereoisomers have at least one descriptor in common, they are diastereomers. If all the descriptors are opposite, they are enantiomers.
A meso compound is an achiral molecule, despite having two or more stereogenic centers. A meso compound is "superimposable" on its mirror image, therefore it reduces the number of stereoisomers predicted by the 2 rule. This occurs because the molecule obtains a plane of symmetry that causes the molecule to rotate around the central carbon–carbon bond. One example is meso-tartaric acid, in which (R,S) is the same as the (S,R) form. In meso compounds the R and S stereocenters occur in symmetrically positioned pairs. | 0 | Theoretical and Fundamental Chemistry |
Two-dimensional diffraction images of a fine synchrotron beam interacting with the specimen are recorded in time frames, such that reflections stemming from individual crystallites of the polycrystalline material can be distinguished. Data treatment is undertaken in a way that diffraction rings are straightened and presented line by line streaked in time. The traces, so-called timelines in azimuthal-angle/time plots resemble to traces of an oscilloscope, giving insight on the processes happening in the material, while undergoing plastic deformation, or heating, or both, These timelines allow to distinguish grain growth or refinement, subgrain formation, slip deformation systems, crystallographic twinning, dynamic recovery, dynamic recrystallization, simultaneously in multiple phases. | 0 | Theoretical and Fundamental Chemistry |
Deoxygenated hemoglobin (deoxyhemoglobin) is the form of hemoglobin without the bound oxygen. The absorption spectra of oxyhemoglobin and deoxyhemoglobin differ. The oxyhemoglobin has significantly lower absorption of the 660 nm wavelength than deoxyhemoglobin, while at 940 nm its absorption is slightly higher. This difference is used for the measurement of the amount of oxygen in a patient's blood by an instrument called a pulse oximeter. This difference also accounts for the presentation of cyanosis, the blue to purplish color that tissues develop during hypoxia.
Deoxygenated hemoglobin is paramagnetic; it is weakly attracted to magnetic fields. In contrast, oxygenated hemoglobin exhibits diamagnetism, a weak repulsion from a magnetic field. | 0 | Theoretical and Fundamental Chemistry |
* [http://outfalls.ifh.uni-karlsruhe.de/links.htm IWA Committee on Marine Outfall Systems]
* [https://web.archive.org/web/20100206083658/http://www.bvsde.paho.org/bvsaca/i/fulltext/alternai/alternai.pdf Salas, Henry J.:Submarine outfalls a viable alternative for sewage discharge of coastal cities in Latin America and the Caribbean], Lima; CEPIS, 2000 | 1 | Applied and Interdisciplinary Chemistry |
Industrial nitric acid production uses the Ostwald process. The combined Ostwald and Haber processes are extremely efficient, requiring only air and natural gas feedstocks.
The Ostwald process' technical innovation is the proper conditions under which anhydrous ammonia burns to nitric oxide (NO) instead of dinitrogen (). The nitric oxide is then oxidized, often with atmospheric oxygen, to nitrogen dioxide ():
The dioxide then disproportionates in water to nitric acid and the nitric oxide feedstock:
The net reaction is maximal oxidation of ammonia:
Dissolved nitrogen oxides are either stripped (in the case of white fuming nitric acid) or remain in solution to form red fuming nitric acid.
Commercial grade nitric acid solutions are usually between 52% and 68% nitric acid by mass, the maximum distillable concentration. Further dehydration to 98% can be achieved with concentrated sulfuric acid|. Historically, higher acid concentrations were also produced by dissolving additional nitrogen dioxide in the acid, but the last plant in the United States ceased using that process in 2012.
More recently, electrochemical means have been developed to produce anhydrous acid from concentrated nitric acid feedstock. | 0 | Theoretical and Fundamental Chemistry |
A colloidal crystal is an ordered array of colloidal particles and fine grained materials analogous to a standard crystal whose repeating subunits are atoms or molecules. A natural example of this phenomenon can be found in the gem opal, where spheres of silica assume a close-packed locally periodic structure under moderate compression. Bulk properties of a colloidal crystal depend on composition, particle size, packing arrangement, and degree of regularity. Applications include photonics, materials processing, and the study of self-assembly and phase transitions. | 0 | Theoretical and Fundamental Chemistry |
Canadian Harold Harvey was among the first to research a "dead" lake. In 1971, he and R. J. Beamish published a report, "Acidification of the La Cloche Mountain Lakes", documenting the gradual deterioration of fish stocks in 60 lakes in Killarney Park in Ontario, which they had been studying systematically since 1966.
In the 1970s and 80s, acid rain was a major topic of research at the Experimental Lakes Area (ELA) in Northwestern Ontario, Canada. Researchers added sulfuric acid to whole lakes in controlled ecosystem experiments to simulate the effects of acid rain. Because its remote conditions allowed for whole-ecosystem experiments, research at the ELA showed that the effect of acid rain on fish populations started at concentrations much lower than those observed in laboratory experiments. In the context of a food web, fish populations crashed earlier than when acid rain had direct toxic effects to the fish because the acidity led to crashes in prey populations (e.g. mysids). As experimental acid inputs were reduced, fish populations and lake ecosystems recovered at least partially, although invertebrate populations have still not completely returned to the baseline conditions. This research showed both that acidification was linked to declining fish populations and that the effects could be reversed if sulfuric acid emissions decreased, and influenced policy in Canada and the United States.
In 1985, seven Canadian provinces (all except British Columbia, Alberta, and Saskatchewan) and the federal government signed the Eastern Canada Acid Rain Program. The provinces agreed to limit their combined sulfur dioxide emissions to 2.3 million tonnes by 1994. The Canada-US Air Quality Agreement was signed in 1991. In 1998, all federal, provincial, and territorial Ministers of Energy and Environment signed The Canada-Wide Acid Rain Strategy for Post-2000, which was designed to protect lakes that are more sensitive than those protected by earlier policies. | 1 | Applied and Interdisciplinary Chemistry |
Improperly folded metal proteins, for example, CCS or Cu-Zn-superoxide dismutase (SOD1) present in brain, blood or other clinical samples, are indicative of neurodegenerative diseases like Alzheimer's disease (AD) or amyotrophic lateral sclerosis (ALS). Active CCS or SOD molecules contribute to intracellular homeostatic control of essential metal ions (e.g., Cu, Zn, Fe, Mn, Ni) in organisms, and thus, these biomolecules can balance pro-oxidative and antioxidative processes in the cytoplasm. Otherwise, free or loosely bound transition metal ions take part in Fenton-like reactions in which deleterious hydroxyl radical is formed, which unrestrained would be destructive to proteins. The loss of active CCS increases the amyloid-β production in neurons which, in turn, is a major pathological hallmark of AD. Therefore, copper chaperone for superoxide dismutase is proposed to be one of the most promising biomarkers of Cu toxicity in these diseases. CCS should be analysed primarily in blood because a meta-analysis of serum data showed that AD patients have higher levels of serum Cu than healthy controls. | 0 | Theoretical and Fundamental Chemistry |
Due to reclassification as UN0508, a class 1.3C explosive, hydroxybenzotriazole and its monohydrate crystal are no longer allowed to be transported by sea or air as per 49CFR (USDOT hazardous materials regulations). However, UNECE draft proposal ECE/TRANS/WP.15/AC.1/HAR/2009/1 has been circulated to UN delegates and, if implemented, would amend current regulations thus allowing for the monohydrate crystal to be shipped under the less-stringent code of UN3474 as a class 4.1 desensitized explosive. | 1 | Applied and Interdisciplinary Chemistry |
Beletskaya is known for her foundational contributions to organometallic chemistry and as one of the first prominent female chemists. Her work helped pave the way for women in Russia to participate in the scientific community. Her pioneering role in organometallic synthesis has laid an essential foundation for future organic chemists. Her work advocating for rare-earth elements in organic chemistry led to the publication of many new textbooks, changing how organic chemistry is taught everywhere. The current field of organic chemists does not always see the need to include other elements in the study of organic chemistry, as it is all carbon-based. Beletskaya’s work helps to expand the use of precious metals in organic reactions. | 0 | Theoretical and Fundamental Chemistry |
The Reichstein process in chemistry is a combined chemical and microbial method for the production of ascorbic acid from D-glucose that takes place in several steps. This process was devised by Nobel Prize winner Tadeusz Reichstein and his colleagues in 1933 while working in the laboratory of the ETH in Zürich. | 0 | Theoretical and Fundamental Chemistry |
An alternate stable form, if it exists, may appear at pressures of at least 50 GPa and temperatures of at least 1,500 K; it has been thought to have an orthorhombic or a double hcp structure. , recent and ongoing experiments are being conducted on high-pressure and superdense carbon allotropes. | 1 | Applied and Interdisciplinary Chemistry |
Because the only form of known life is that on Earth, the search for biosignatures is heavily influenced by the products that life produces on Earth. However, life that is different than life on Earth may still produce biosignatures that are detectable by humans, even though nothing is known about their specific biology. This form of biosignature is called an "agnostic biosignature" because it is independent of the form of life that produces it. It is widely agreed that all life–no matter how different it is from life on Earth–needs a source of energy to thrive. This must involve some sort of chemical disequilibrium, which can be exploited for metabolism. Geological processes are independent of life, and if scientists can constrain the geology well enough on another planet, then they know what the particular geologic equilibrium for that planet should be. A deviation from geological equilibrium can be interpreted as an atmospheric disequilibrium and agnostic biosignature. | 1 | Applied and Interdisciplinary Chemistry |
The history of process simulation is related to the development of the computer science and of computer hardware and programming languages. Early implementations of partial aspects of chemical processes were introduced in the 1970s when suitable hardware and software (here mainly the programming languages FORTRAN and C) became available. The modelling of chemical properties began much earlier, notably the cubic equation of states and the Antoine equation were precursory developments of the 19th century. | 1 | Applied and Interdisciplinary Chemistry |
In a gas or liquid, sound consists of compression waves. In solids, waves propagate as two different types. A longitudinal wave is associated with compression and decompression in the direction of travel, and is the same process in gases and liquids, with an analogous compression-type wave in solids. Only compression waves are supported in gases and liquids. An additional type of wave, the transverse wave, also called a shear wave, occurs only in solids because only solids support elastic deformations. It is due to elastic deformation of the medium perpendicular to the direction of wave travel; the direction of shear-deformation is called the "polarization" of this type of wave. In general, transverse waves occur as a pair of orthogonal polarizations.
These different waves (compression waves and the different polarizations of shear waves) may have different speeds at the same frequency. Therefore, they arrive at an observer at different times, an extreme example being an earthquake, where sharp compression waves arrive first and rocking transverse waves seconds later.
The speed of a compression wave in a fluid is determined by the mediums compressibility and density. In solids, the compression waves are analogous to those in fluids, depending on compressibility and density, but with the additional factor of shear modulus which affects compression waves due to off-axis elastic energies which are able to influence effective tension and relaxation in a compression. The speed of shear waves, which can occur only in solids, is determined simply by the solid materials shear modulus and density. | 1 | Applied and Interdisciplinary Chemistry |
Symbiotic fermentation is a form of fermentation in which multiple organisms (yeasts, acetic acid bacteria, lactic acid bacteria and others) interact in symbiosis in order to produce the desired product. For example, a yeast may produce ethanol, which is then consumed by an acetic acid bacterium. Described early on as the fermentation of sugars following saccharification in a mixed fermentation process. | 1 | Applied and Interdisciplinary Chemistry |
If an ion contains unpaired electrons, it is called a radical ion. Just like uncharged radicals, radical ions are very reactive. Polyatomic ions containing oxygen, such as carbonate and sulfate, are called oxyanions. Molecular ions that contain at least one carbon to hydrogen bond are called organic ions. If the charge in an organic ion is formally centred on a carbon, it is termed a carbocation (if positively charged) or carbanion (if negatively charged). | 0 | Theoretical and Fundamental Chemistry |
The synthesis of three kinds of "jeewanu" have been reported; two of them were organic, and the other was inorganic. Other similar inorganic structures have also been produced. The investigating scientist (V. O. Kalinenko) referred to them as "bio-like structures" and "artificial cells". Formed in distilled water (as well as on agar gel) under the influence of an electric field, they lack protein, amino acids, purine or pyrimidine bases, and certain enzyme activities. According to NASA researchers, "presently known scientific principles of biology and biochemistry cannot account for living inorganic units" and "the postulated existence of these living units has not been proved". | 0 | Theoretical and Fundamental Chemistry |
For an Authority Having Jurisdiction, combustibility is defined by the local code. In the National Building Code of Canada, it is defined as follows:
*Combustible: A material that fails to meet acceptance criteria of [https://web.archive.org/web/20061003193651/http://www.ulc.ca/About_ulc/Publication_Notice_Detail.asp?PN_ID=31 CAN/ULC-S114, Standard Method of Test for Determination of Non-combustibility in Building Materials].
*Non-combustible: means that a material meets the acceptance criteria of [https://web.archive.org/web/20061003193651/http://www.ulc.ca/About_ulc/Publication_Notice_Detail.asp?PN_ID=31 CAN4-S114, "Standard Method of Test for Determination of Non-Combustibility in Building Materials]".
BS 476-4:1970 defines a test for combustibility in which a technician heats three specimens of a material in a furnace. Combustibile materials are those for which any of the three specimens either:
* Makes the temperature reading from either of two thermocouples rise by 50 degrees Celsius or more above the initial furnace temperature
* Flame continuously for 10 seconds or more inside the furnace
Otherwise, the material is classified as non-combustible. | 0 | Theoretical and Fundamental Chemistry |
A disk mounted on a sphere is “wobbled” about an axis by the fluid flow and each rotation represents a finite amount of fluid transferred.
A nutating disc flow meter has a round disc mounted on a spindle in a cylindrical chamber. By tracking the movements of the spindle, the flow meter determines the number of times the chamber traps and empties fluid. This information is used to determine the flow rate. | 1 | Applied and Interdisciplinary Chemistry |
In aquatic environments, oxygen saturation is a ratio of the concentration of "dissolved oxygen" (DO, O), to the maximum amount of oxygen that will dissolve in that water body, at the temperature and pressure which constitute stable equilibrium conditions. Well-aerated water (such as a fast-moving stream) without oxygen producers or consumers is 100% saturated.
It is possible for stagnant water to become somewhat supersaturated with oxygen (i.e. reach more than 100% saturation) either because of the presence of photosynthetic aquatic oxygen producers or because of a slow equilibration after a change of atmospheric conditions. Stagnant water in the presence of decaying matter will typically have an oxygen concentration much less than 100%, which is due to anaerobic bacteria being much less efficient at breaking down organic material. Similarly as in water, oxygen concentration also plays a key role in the breakdown of organic matter in soils. Higher oxygen saturation allows for aerobic bacteria to persist, which break down decaying organic material in soils much more efficiently than anaerobic bacteria. Thus soils with high oxygen saturation will have less organic matter per volume than those with low oxygen saturation.
Environmental oxygenation can be important to the sustainability of a particular ecosystem. The US Environmental Protection Agency has published a table of maximum equilibrium dissolved oxygen concentration versus temperature at atmospheric pressure. The optimal levels in an estuary for dissolved oxygen is higher than 6 ppm. Insufficient oxygen (environmental hypoxia), often caused by the decomposition of organic matter and/or nutrient pollution, may occur in bodies of water such as ponds and rivers, tending to suppress the presence of aerobic organisms such as fish. Deoxygenation increases the relative population of anaerobic organisms such as plants and some bacteria, resulting in fish kills and other adverse events. The net effect is to alter the balance of nature by increasing the concentration of anaerobic over aerobic species. | 0 | Theoretical and Fundamental Chemistry |
The intensity as a function of the path length difference (also denoted as retardation) in the interferometer and wavenumber is
where is the spectrum to be determined. Note that it is not necessary for to be modulated by the sample before the interferometer. In fact, most FTIR spectrometers place the sample after the interferometer in the optical path. The total intensity at the detector is
This is just a Fourier cosine transform. The inverse gives us our desired result in terms of the measured quantity : | 0 | Theoretical and Fundamental Chemistry |
A nanoparticle sizer, also known as a nanoparticle analyzer, is a device used to measure the size, size distribution, and concentration of nanoparticles in a sample. The size of nanoparticles is typically in the range of 1 to 100 nanometers (nm), and they are much smaller than the particles that can be measured with conventional particle size analyzers. | 0 | Theoretical and Fundamental Chemistry |
Faulds worked as a postdoctoral researcher for on the detection of DNA using surface-enhanced resonant Raman spectroscopy (SERRS). She became increasingly interested in the use of analytical chemistry to improve people's lives. Faulds was appointed as a lecturer in 2006.
Faulds was promoted to Reader in 2012 and Professor in 2015. Faulds works on the development of surface-enhanced Raman spectroscopy (SERS) for analytical detection. SERSs permits multiplexed and sensitive biological analysis. Her work uses signal amplification methods for the quantitative analysis of biomolecules, as the sensitivity allows her to detect target DNA and proteins. SERS also allows Faulds to make multiple measurements of different analytes in one sample. In 2015 she was the first woman and youngest person to ever be elected chair of the Infrared and Raman Discussion Group (IRDG). She has described C. V. Raman as her "hero of spectroscopy".
Her recent work has looked at the optical detection of Listeria using bionanosensors. The bionanosensors permit the multiplexed detection of pathogens, which can remove the risk of infectious diseases without the need for antimicrobial drugs. She covers SERS active magnetic nanoparticles with lectins, which can recognise and bind to carbohydrates in bacteria. These nanoparticles can collect and concentrate bacteria from production lines. Silver nanoparticles are functionalised with a biorecognition molecule, such as an aptamer, and Raman reporter, resulting in a SERS signal when a nanoparticle binds to the bacterial target. The magnetic component can then be studied further using portable Raman spectrometers.
Faulds is a founding member of Renishaw plc diagnostics, a University of Strathclyde spin-off company, and serves as its Director of Research. Faulds joined the editorial board of RSC Advances in November 2016 and as Associate Editor of Analyst in August 2020. She co-directs the Engineering and Physical Sciences Research Council (EPSRC) and Medical Research Council (MRC) Centre for Doctoral Training (CDT) in Optical Medical Imaging, shared between the University of Edinburgh and the University of Strathclyde. | 0 | Theoretical and Fundamental Chemistry |
The great oxygenation event began with the biologically induced appearance of oxygen in the Earth's atmosphere about 2.45 billion years ago. The rise of oxygen levels due to cyanobacterial photosynthesis in ancient microenvironments was probably highly toxic to the surrounding biota. Under these conditions, the selective pressure of oxidative stress is thought to have driven the evolutionary transformation of an archaeal lineage into the first eukaryotes. Oxidative stress might have acted in synergy with other environmental stresses (such as ultraviolet radiation and/or desiccation) to drive this selection. Selective pressure for efficient repair of oxidative DNA damages may have promoted the evolution of eukaryotic sex involving such features as cell-cell fusions, cytoskeleton-mediated chromosome movements and emergence of the nuclear membrane. Thus, the evolution of meiotic sex and eukaryogenesis may have been inseparable processes that evolved in large part to facilitate repair of oxidative DNA damages. | 1 | Applied and Interdisciplinary Chemistry |
Monoclonal antibodies for research applications can be found directly from antibody suppliers, or through use of a specialist search engine like CiteAb. Below are examples of clinically important monoclonal antibodies. | 1 | Applied and Interdisciplinary Chemistry |
MesoHABSIM builds upon pre-existing physical habitat simulation models (e.g. PHABSIM) which is an essential component of the United States government's methods for establishing minimum stream flow requirements.
MesoHABSIM is an augmentation of this system, designed during a restoration study of the Quinebaug River. The changing spatial distributions of physical attributes of a river as a result of variations in flow and the biological responses of aquatic species to these changes, provide the basis for simulating the consequences of ecosystem alteration, and consequently the justification of restoration measures. MesoHABSIM modifies the data acquisition technique and analytical approach of similar models by changing the scale of resolution from micro- to meso-scales. Due to this increase in scale, the model takes variations in stream morphology along the river into account and allows for application in larger-scale projects. | 1 | Applied and Interdisciplinary Chemistry |
Eudistomin U is a β-carboline derivative. The structure of this molecule is made up of a β-carboline with an aromatic indole at the 1 position, thus also functioning as an indole. Eudistomin C is also a cytotoxic molecule, and its cytotoxicity have been shown to affect certain cancer cell line and human pathogens. A recent study suggested that this cytotoxicity may allow Eudistomin C to bind to DNA molecules. In addition to this, Eudistomin C displayed antibacterial property in Gram-Positive Bacteria. This is due to Eudistomin C damaging the bacterias cell membrane and interfering with the DNA gyrase function, which directly leads to cell death. | 1 | Applied and Interdisciplinary Chemistry |
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