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Homeobox protein NANOG (hNanog) is a transcriptional factor that helps embryonic stem cells (ESCs) maintain pluripotency by suppressing cell determination factors. hNanog is encoded in humans by the NANOG gene. Several types of cancer are associated with NANOG. | 1 | Applied and Interdisciplinary Chemistry |
Many methods for encoding data in DNA are possible. The optimal methods are those that make economical use of DNA and protect against errors. If the message DNA is intended to be stored for a long period of time, for example, 1,000 years, it is also helpful if the sequence is obviously artificial and the reading frame is easy to identify. | 1 | Applied and Interdisciplinary Chemistry |
The Indian Academy of Sciences elected George as a fellow in 1973 before he became an elected fellow of the Indian National Science Academy in 1975. The Council of Scientific and Industrial Research awarded him the Shanti Swarup Bhatnagar Prize, one of the highest Indian science awards, in 1973. He received the C. V. Raman Award in 1985 and the Professor T. R. Seshadri 70th Birthday Commemoration Medal of the Indian National Science Academy in 1990. The World Academy of Sciences awarded him the TWAS Prize in 1992 and two years later, elected him as their fellow. He is also a recipient of the Lifetime Achievement Award of the Chemical Research Society of India and a life member of the society. | 0 | Theoretical and Fundamental Chemistry |
The formula for degree of unsaturation is:
where n is the number of atoms with valence v.
That is, an atom that has a valence of x contributes a total of x − 2 to the degree of unsaturation. The result is then halved and increased by 1. | 0 | Theoretical and Fundamental Chemistry |
Carbamino refers to an adduct generated by the addition of carbon dioxide to the free amino group of an amino acid or a protein, such as hemoglobin forming carbaminohemoglobin. | 0 | Theoretical and Fundamental Chemistry |
In chemistry, a reaction mechanism is the step by step sequence of elementary reactions by which overall chemical reaction occurs.
A chemical mechanism is a theoretical conjecture that tries to describe in detail what takes place at each stage of an overall chemical reaction. The detailed steps of a reaction are not observable in most cases. The conjectured mechanism is chosen because it is thermodynamically feasible and has experimental support in isolated intermediates (see next section) or other quantitative and qualitative characteristics of the reaction. It also describes each reactive intermediate, activated complex, and transition state, which bonds are broken (and in what order), and which bonds are formed (and in what order). A complete mechanism must also explain the reason for the reactants and catalyst used, the stereochemistry observed in reactants and products, all products formed and the amount of each.
The electron or arrow pushing method is often used in illustrating a reaction mechanism; for example, see the illustration of the mechanism for benzoin condensation in the following examples section.
A reaction mechanism must also account for the order in which molecules react. Often what appears to be a single-step conversion is in fact a multistep reaction. | 0 | Theoretical and Fundamental Chemistry |
Another information-theoretic metric is variation of information, which is roughly a symmetrization of conditional entropy. It is a metric on the set of partitions of a discrete probability space. | 0 | Theoretical and Fundamental Chemistry |
The metal ions can also be arranged in order of increasing Δ, and this order is largely independent of the identity of the ligand.
:Mn
In general, it is not possible to say whether a given ligand will exert a strong field or a weak field on a given metal ion. However, when we consider the metal ion, the following two useful trends are observed:
*Δ increases with increasing oxidation number, and
*Δ increases down a group. | 0 | Theoretical and Fundamental Chemistry |
Anhydrous aluminium chloride is hygroscopic, having a very pronounced affinity for water. It fumes in moist air and hisses when mixed with liquid water as the Cl ligands are displaced with HO molecules to form the hexahydrate . The anhydrous phase cannot be regained on heating the hexahydrate. Instead HCl is lost leaving aluminium hydroxide or alumina (aluminium oxide):
Like metal aquo complexes, aqueous is acidic owing to the ionization of the aquo ligands:
Aqueous solutions behave similarly to other aluminium salts containing hydrated ions, giving a gelatinous precipitate of aluminium hydroxide upon reaction with dilute sodium hydroxide: | 0 | Theoretical and Fundamental Chemistry |
The most fundamental difference between SUV and K values is that SUV is a simple measure of uptake, which is normalized to body weight and injected activity. The SUV does not take into consideration the tracer delivery to the local region of interest from where the measurements are obtained, therefore, affected by the physiological process consuming [F]NaF elsewhere in the body. On the other hand, K measures the plasma clearance to bone mineral, taking into account the tracer uptake elsewhere in the body affecting the delivery of tracer to the region of interest from where the measurements are obtained. The difference in the measurement of K and SUV in bone tissue using [F]NaF are explained in more detail by Blake et al.
It is critical to note that most of the methods for calculating K require dynamic PET scanning over an hour, except, the Siddique–Blake methods. Dynamic scanning is complicated and costly. However, the calculation of SUV requires a single static PET scan performed approximately 45–60 minutes post-tracer injection at any region imaged within the skeleton.
Many researchers have shown a high correlation between SUV and K values at various skeletal sites. However, SUV and K methods can contradict for measuring response to treatment. Since SUV has not been validated against the histomorphometry, its usefulness in bone studies measuring response to treatment and disease progression is uncertain. | 1 | Applied and Interdisciplinary Chemistry |
The catecholamines are a group of neurotransmitters composed of the endogenous substances dopamine, noradrenaline (norepinephrine), and adrenaline (epinephrine), as well as numerous artificially synthesized compounds such as isoprenaline - an anti-bradycardiac medication. Their investigation constitutes a major chapter in the history of physiology, biochemistry, and pharmacology. Adrenaline was the first hormone extracted from an endocrine gland and obtained in pure form, before the word hormone was coined. Adrenaline was also the first hormone whose structure and biosynthesis was discovered. Second to acetylcholine, adrenaline and noradrenaline were some of the first neurotransmitters discovered, and the first intercellular biochemical signals to be found in intracellular vesicles. The β-adrenoceptor gene was the first G protein-coupled receptor to be cloned. | 1 | Applied and Interdisciplinary Chemistry |
Sulfur trioxide pyridine complex is the compound with the formula CHNSO. It is a colourless solid that dissolves in polar organic solvents. It is the adduct formed from the Lewis base pyridine and the Lewis acid sulfur trioxide. The compound is mainly used as a source of sulfur trioxide, for example in the synthesis of sulfate esters from alcohols:
:ROH + CHNSO → [CHNH][ROSO]
It also is useful for sulfamations:
:RNH + CHNSO → CHN + RNSOH
The compound is used for sulfonylation reactions, especially in the sulfonylation of furans. It is also an activating electrophile in a Parikh-Doering oxidation. | 0 | Theoretical and Fundamental Chemistry |
Mineral paint contains inorganic colorants, and potassium-based, alkali silicate (water glass), also known as potassium silicate, liquid potassium silicate, or LIQVOR SILICIVM. A coat with mineral colors does not form a layer but instead permanently bonds to the substrate material (silicification).
The result is a highly durable connection between paint coat and substrate. The water glass binding agent is highly resistant to UV light. While dispersions based on acrylate or silicone resin over the years tend to grow brittle, chalky, and crack under UV, the inorganic binder water glass remains stable. The chemical fusion with the substrate and the UV stability of the binder are the fundamental reasons for the extraordinarily high lifetime of silicate paints.
Silicate paints require siliceous substrate for setting. For this reason they are highly suitable for mineral substrates such as mineral plasters and concrete, thus they are of only limited use for application on wood and metal. The permeability to water vapor of silicate paints is equivalent to that of the substrate, so silicate paints do not inhibit the diffusion of water vapor. Moisture contained in parts of a structure or in the plaster may diffuse outward without resistance: this keeps walls dry and prevents structural damage. This addition helps avoid condensation of water on the surface of building materials, reducing the risk of infestation by algae and fungi. The high alkalinity of the water glass binding agent adds to the inhibitory effect against infestation by microorganisms and eliminates the need for additional preservatives.
As mineral paint coats are not prone to static charging and thermo-plasticity (stickiness developing under heat), which is common for surfaces coated with dispersion or silicone resin, soiling happens less, so fewer dirt particles cling to the surface and are easier to wash off. Silicate paints are incombustible and free of organic additives or solvents (DIN 18363 Painting and coating work Section 2.4.1).
Silicate paints are highly color-tone stable. As they are solely colored with mineral pigments that do not fade with exposure to UV radiation, the silicate paint coats remain constant in color for decades.
Silicate paints are based upon mineral raw materials. They are environmentally compatible in manufacture and effect. Their high durability helps to preserve resources, and their contaminant-free composition preserves health and environment. For this reason, silicate paints have gained popularity, especially in sustainable construction. | 0 | Theoretical and Fundamental Chemistry |
The three prime untranslated regions (3UTRs) of messenger RNAs (mRNAs) often contain regulatory sequences that post-transcriptionally cause gene silencing. Such 3-UTRs often contain both binding sites for microRNAs (miRNAs) as well as for regulatory proteins. By binding to specific sites within the 3-UTR, a large number of specific miRNAs decrease gene expression of their particular target mRNAs by either inhibiting translation or directly causing degradation of the transcript, using a mechanism similar to RNA interference (see MicroRNA). The 3-UTR also may have silencer regions that bind repressor proteins that inhibit the expression of an mRNA.
The 3-UTR often contains microRNA response elements (MREs). MREs are sequences to which miRNAs bind and cause gene silencing. These are prevalent motifs within 3-UTRs. Among all regulatory motifs within the 3'-UTRs (e.g. including silencer regions), MREs make up about half of the motifs.
As of 2014, the miRBase web site, an archive of miRNA sequences and annotations, listed 28,645 entries in 233 biologic species. Of these, 1,881 miRNAs were in annotated human miRNA loci. miRNAs were predicted to each have an average of about four hundred target mRNAs (causing gene silencing of several hundred genes). Freidman et al. estimate that >45,000 miRNA target sites within human mRNA 3'UTRs are conserved above background levels, and >60% of human protein-coding genes have been under selective pressure to maintain pairing to miRNAs.
Direct experiments show that a single miRNA can reduce the stability of hundreds of unique mRNAs. Other experiments show that a single miRNA may repress the production of hundreds of proteins, but that this repression often is relatively mild (less than 2-fold).
The effects of miRNA dysregulation of gene expression seem to be important in cancer. For instance, in gastrointestinal cancers, nine miRNAs have been identified as epigenetically altered and effective in down regulating DNA repair enzymes.
The effects of miRNA dysregulation of gene expression also seem to be important in neuropsychiatric disorders, such as schizophrenia, bipolar disorder, major depression, Parkinsons disease, Alzheimers disease and autism spectrum disorders. | 1 | Applied and Interdisciplinary Chemistry |
Phases can also be inferred by using a process called molecular replacement, where a similar molecules already-known phases are grafted onto the intensities of the molecule at hand, which are observationally determined. These phases can be obtained experimentally from a homologous molecule or if the phases are known for the same molecule but in a different crystal, by simulating the molecules packing in the crystal and obtaining theoretical phases. Generally, these techniques are less desirable since they can severely bias the solution of the structure. They are useful, however, for ligand binding studies, or between molecules with small differences and relatively rigid structures (for example derivatizing a small molecule). | 0 | Theoretical and Fundamental Chemistry |
The Pfizer Award in Enzyme Chemistry, formerly known as the Paul-Lewis Award in Enzyme Chemistry was established in 1945. Consisting of a gold medal and honorarium, its purpose is to stimulate fundamental research in enzyme chemistry by scientists not over forty years of age. The award is administered by the Division of Biological Chemistry of the American Chemical Society and sponsored by Pfizer. The award was terminated in 2022. | 1 | Applied and Interdisciplinary Chemistry |
Dihydrokaempferol 4-reductase uses cis-3,4-leucopelargonidin and NADP to produce (+)-aromadendrin, NADPH, and H.
Leucoanthocyanidin reductase transforms cis-3,4-leucopelargonidin into afzelechin. | 1 | Applied and Interdisciplinary Chemistry |
Methyl violet is a mutagen and mitotic poison, therefore concerns exist regarding the ecological impact of the release of methyl violet into the environment. Methyl violet has been used in vast quantities for textile and paper dyeing, and 15% of such dyes produced worldwide are released to environment in wastewater. Numerous methods have been developed to treat methyl violet pollution. The three most prominent are chemical bleaching, biodegradation, and photodegradation. | 0 | Theoretical and Fundamental Chemistry |
Boussinesq (1885) and Basset (1888) found that the force F on an accelerating spherical particle in a viscous fluid is
where D is the particle diameter, and u and v are the fluid and particle velocity vectors, respectively. | 1 | Applied and Interdisciplinary Chemistry |
The journal is abstracted and indexed in:
According to the Journal Citation Reports, the journal has a 2012 impact factor of 1.435, ranking it 12th out of 75 journals in the category "Metallurgy & Metallurgical Engineering". | 1 | Applied and Interdisciplinary Chemistry |
* "Río, Andrés Manuel del," Enciclopedia de México, v. 12. Mexico City, 1987.
* Alessio Robles, Vito. El ilustre maestro Andrés Manuel del Río. Mexico City, 1937. 31 p.
* Arnaiz y Freg, Arturo. Andrés Manuel del Río: Estudio biográfico. Mexico City: Casino Español de México, 1936.
* Arnaiz y Freg, Arturo. Don Andrés del Río, descubrimiento del Eritronio (Vanadio). Mexico City: Cultura, 1948. 44 p.
* Prieto, Carlos et al. Andrés Manuel del Río y su obra científica: Segundo centenario de su natalicio, 1764–1964. México: Compañía Fundidora de Fierro y Acero de Monterrey, 1966. 81 p.
* Ramírez, Santiago E. Biografía del sr. D. Andrés Manuel del Río: Primer catedrático de mineralogía del Colegio de Minería. México: Imp. del Sagrado Corazón de Jesús, 1891. 56 p.
* Ramírez, Santiago. Ensayos biográficos de Joaquín Velásquez de León y Andrés Manuel del Río. México: UNAM, Facultad de Ingeniería, Sociedad de ex-alumnos, 1983.
* Rojo, Onofre. La prioridad en los descubrimientos y su relación con la infraestructura científica. Avance y Perspectiva 20: 107-111 (1997). .
A short biography of Andrés Manuel del Río is found in "Oxford Dictionary of Scientists" by Oxford University Press, 1999. | 1 | Applied and Interdisciplinary Chemistry |
A third-order derivative term represneting dispersion of wavenumbers are often encountered in many applications. The disperseively modified Kuramoto–Sivashinsky equation, which is often called as the Kawahara equation, is given by
where is real parameter. A fifth-order derivative term is also often included, which is the modified Kawahara equation and is given by | 1 | Applied and Interdisciplinary Chemistry |
Inositol hexaphosphate (IP6) is the most abundant inositol phosphate isomer found. IP6 is solely involved in various biological activities such as neurotransmission, immune response, regulation of kinase and phosphatase proteins as well as activation of calcium channels. IP6 is also involved in ATP regeneration seen in plants as well as insulin exocytosis in pancreatic β cells.
Inositol hexaphosphate also facilitates the formation of the six-helix bundle and assembly of the immature HIV-1 Gag lattice. IP6 makes ionic contacts with two rings of lysine residues at the centre of the Gag hexamer. Proteolytic cleavage then unmasks an alternative binding site, where IP6 interaction promotes the assembly of the mature capsid lattice. These studies identify IP6 as a naturally occurring small molecule that promotes both assembly and maturation of HIV-1. | 1 | Applied and Interdisciplinary Chemistry |
Asymmetric hydrogenations operate by conventional mechanisms invoked for other hydrogenations. This includes inner sphere mechanisms, outer sphere mechanisms and the σ-bond metathesis mechanisms. The type of mechanism employed by a catalyst is largely dependent on the ligands used in a system, which in turn leads to certain catalyst-substrate affinities. | 0 | Theoretical and Fundamental Chemistry |
Prior to the emergence of underwater cabled observatories, oceanographers and other researchers studying the global ocean tended to rely on the use of research vessels and manned submersibles in order to collect data. This was followed by a shift toward Remote Operated Vehicles (ROV's) and space-based research satellites. The limitation to these methods was that they were either not cost-effective, or data could only be collected for short durations. While the importance of expedition-based exploration was recognized, a solution was needed.
In 1987, the concept of utilizing high-power, high-bandwidth underwater cabled observatories emerged as a long-term, cost-effective solution for conducting real-time monitoring of ocean systems.
In the early 1990s, the United States and Canada formed an agreement to develop a plate-scale submarine electro-optically cabled ocean observatory in the northeast Pacific Ocean. This region is home to the smallest of Earth's tectonic plates – the Juan de Fuca plate. The small size and close coastal proximity of the Juan de Fuca plate presents a unique opportunity to observe the dynamic systems in submarine volcano regions.
The partnership between the U.S. and Canada developed into a plan to build a Canadian cabled array that would cover the upper 1/3 of the Juan de Fuca plate, and a U.S. system spanning the lower 2/3 of the plate (cite). Together, this plate-scale observatory would be called NEPTUNE (Northeast Pacific Time Series Underwater Networked Experiments) and would provide continuous observations for 25 years.
By the mid-2000s, NEPTUNE Canada had received full funding and their cabled array was completed and online by 2009. It was brought under the umbrella network of Ocean Networks Canada (ONC). Meanwhile, NEPTUNE U.S. was renamed to Regional Scale Nodes and became a component of the OOI. It is slated for completion in 2014. Both NEPTUNE Canada and RSN will be integrated through the ONC's digital infrastructure and the OOI Cyberinfrastructure providing real-time access to anyone connected to the Internet. | 0 | Theoretical and Fundamental Chemistry |
Prostaglandin H (PGH), or prostaglandin H2 (PGH2), is a type of prostaglandin and a precursor for many other biologically significant molecules. It is synthesized from arachidonic acid in a reaction catalyzed by a cyclooxygenase enzyme. The conversion from arachidonic acid to prostaglandin H2 is a two-step process. First, COX-1 catalyzes the addition of two free oxygens to form the 1,2-dioxane bridge and a peroxide functional group to form prostaglandin G2 (PGG2). Second, COX-2 reduces the peroxide functional group to a secondary alcohol, forming prostaglandin H2. Other peroxidases like hydroquinone have been observed to reduce PGG2 to PGH2. PGH2 is unstable at room temperature, with a half life of 90-100 seconds, so it is often converted into a different prostaglandin.
It is acted upon by:
* Prostacyclin synthase to create prostacyclin
* Thromboxane-A synthase to create thromboxane A2 and 12-(S)-hydroxy-5Z,8E,10E-heptadecatrienoic acid (HHT) (see 12-Hydroxyheptadecatrienoic acid)
* Prostaglandin D2 synthase to create prostaglandin D2
* Prostaglandin E synthase to create prostaglandin E2
It rearranges non-enzymatically to:
* A mixture of 12-(S)-hydroxy-5Z,8E,10E-heptadecatrienoic acid (HHT) and 12-(S)-hydroxy-5Z,8Z,10E-heptadecatrienoic acid (see 12-hydroxyheptadecatrienoic acid)
Functions of prostaglandin H:
* regulating the constriction and dilation of blood vessels
* stimulating platelet aggregation
**binds to thromboxane receptor on platelets' cell membranes to trigger platelet migration and adhesion to other platelets.
Effects of aspirin on prostaglandin H:
* Aspirin has been hypothesized to block the conversion of arachidonic acid to prostaglandin | 1 | Applied and Interdisciplinary Chemistry |
DABCO is used as a nucleophilic catalyst for:
*formation of polyurethane from alcohol and isocyanate functionalized monomers and pre-polymers.
*Baylis–Hillman reactions of aldehydes and unsaturated ketones and aldehydes. | 0 | Theoretical and Fundamental Chemistry |
Blood lactate levels are also maintained at steady state. At rest or low levels of exercise, the rate of lactate production in muscle cells and consumption in muscle or blood cells allows lactate to remain in the body at a certain steady state concentration. If a higher level of exercise is sustained, however, blood lactose levels will increase before becoming constant, indicating that a new steady state of elevated concentration has been reached. Maximal lactate steady state (MLSS) refers to the maximum constant concentration of lactase reached during sustained high-activity. | 0 | Theoretical and Fundamental Chemistry |
If we differentiate this last equation with respect to at constant we get:
Since we know from the Gibbs potential equation that:
with the molar volume , these last two equations put together give:
Since all this, done as a pure substance, is valid in an ideal mix just adding the subscript to all the intensive variables and changing to , with optional overbar, standing for partial molar volume:
Applying the first equation of this section to this last equation we find:
which means that the partial molar volumes in an ideal mix are independent of composition. Consequently, the total volume is the sum of the volumes of the components in their pure forms: | 0 | Theoretical and Fundamental Chemistry |
Enolisation of RuBP is the conversion of the keto tautomer of RuBP to an enediol(ate). Enolisation is initiated by deprotonation at C3. The enzyme base in this step has been debated, but the steric constraints observed in crystal structures have made Lys210 the most likely candidate. Specifically, the carbamate oxygen on Lys210 that is not coordinated with the Mg ion deprotonates the C3 carbon of RuBP to form a 2,3-enediolate. | 0 | Theoretical and Fundamental Chemistry |
The study of thermodynamical systems has developed into several related branches, each using a different fundamental model as a theoretical or experimental basis, or applying the principles to varying types of systems. | 0 | Theoretical and Fundamental Chemistry |
As PRR is a family of genes, several rounds mutant screening have been performed to identify each possible phenotype. | 1 | Applied and Interdisciplinary Chemistry |
The Association for Materials Protection and Performance (AMPP), is a professional association focused on the protection of assets and performance of materials. AMPP was created when NACE International and SSPC the Society for Protective Coatings merged in 2021. AMPP is active in more than 130 countries and has more than 40,000 members. AMPP is headquartered in the U.S. with offices in Houston, Texas and Pittsburgh, Pennsylvania. Additional offices are located in the U.K., China, Malaysia, Brazil, and Saudi Arabia with a training center in Dubai. | 1 | Applied and Interdisciplinary Chemistry |
Complementarity can be found between short nucleic acid stretches and a coding region or a transcribed gene, and results in base pairing. These short nucleic acid sequences are commonly found in nature and have regulatory functions such as gene silencing. | 1 | Applied and Interdisciplinary Chemistry |
An alternative to measure BOD is the development of biosensors, which are devices for the detection of an analyte that combines a biological component with a physicochemical detector component. Enzymes are the most widely used biological sensing elements in the fabrication of biosensors. Their application in biosensor construction is limited by the tedious, time-consuming and costly enzyme purification methods. Microorganisms provide an ideal alternative to these bottlenecks.
Many micro organisms useful for BOD assessment are relatively easy to maintain in pure cultures, grow and harvest at low cost. Moreover, the use of microbes in the field of biosensors has opened up new possibilities and advantages such as ease of handling, preparation and low cost of device. A number of pure cultures, e.g. Trichosporon cutaneum, Bacillus cereus, Klebsiella oxytoca, Pseudomonas sp. etc. individually, have been used by many workers for the construction of BOD biosensor. On the other hand, many workers have immobilized activated sludge, or a mixture of two or three bacterial species and on various membranes for the construction of BOD biosensor. The most commonly used membranes were polyvinyl alcohol, porous hydrophilic membranes etc.
A defined microbial consortium can be formed by conducting a systematic study, i.e. pre-testing of selected micro-organisms for use as a seeding material in BOD analysis of a wide variety of industrial effluents. Such a formulated consortium can be immobilized on suitable membrane, i.e. charged nylon membrane. Charged nylon membrane is suitable for microbial immobilization, due to the specific binding between negatively charged bacterial cell and positively charged nylon membrane. So the advantages of the nylon membrane over the other membranes are : The dual binding, i.e. Adsorption as well as entrapment, thus resulting in a more stable immobilized membrane. Such specific Microbial consortium based BOD analytical devices, may find great application in monitoring of the degree of pollutant strength, in a wide variety of industrial waste water within a very short time.
Biosensors can be used to indirectly measure BOD via a fast (usually <30 min) to be determined BOD substitute and a corresponding calibration curve method (pioneered by Karube et al., 1977). Consequently, biosensors are now commercially available, but they do have several limitations such as their high maintenance costs, limited run lengths due to the need for reactivation, and the inability to respond to changing quality characteristics as would normally occur in wastewater treatment streams; e.g. diffusion processes of the biodegradable organic matter into the membrane and different responses by different microbial species which lead to problems with the reproducibility of result (Praet et al., 1995). Another important limitation is the uncertainty associated with the calibration function for translating the BOD substitute into the real BOD (Rustum et al., 2008). | 0 | Theoretical and Fundamental Chemistry |
Haloalkanes are a class of molecule that is defined by a carbon–halogen bond. This bond can be relatively weak (in the case of an iodoalkane) or quite stable (as in the case of a fluoroalkane). In general, with the exception of fluorinated compounds, haloalkanes readily undergo nucleophilic substitution reactions or elimination reactions. The substitution on the carbon, the acidity of an adjacent proton, the solvent conditions, etc. all can influence the outcome of the reactivity. | 0 | Theoretical and Fundamental Chemistry |
PPR3, PRR5, PRR7, and PRR9 are all paralogs of each other. They have similar structure, and all repress the transcription of CCA1 and LHY. Additionally, they are all characterized by their lack of a phospho-accepting aspartate site. These genes are also paralogs to TOC1, which is alternatively called PRR1. | 1 | Applied and Interdisciplinary Chemistry |
The magazine is abstracted and indexed in Chemical Abstracts Service, Science Citation Index, and Scopus. | 1 | Applied and Interdisciplinary Chemistry |
Dispersion and nonlinearity can interact to produce permanent and localized wave forms. Consider a pulse of light traveling in glass. This pulse can be thought of as consisting of light of several different frequencies. Since glass shows dispersion, these different frequencies travel at different speeds and the shape of the pulse therefore changes over time. However, also the nonlinear Kerr effect occurs; the refractive index of a material at a given frequency depends on the lights amplitude or strength. If the pulse has just the right shape, the Kerr effect exactly cancels the dispersion effect and the pulses shape does not change over time. Thus, the pulse is a soliton. See soliton (optics) for a more detailed description.
Many exactly solvable models have soliton solutions, including the Korteweg–de Vries equation, the nonlinear Schrödinger equation, the coupled nonlinear Schrödinger equation, and the sine-Gordon equation. The soliton solutions are typically obtained by means of the inverse scattering transform, and owe their stability to the integrability of the field equations. The mathematical theory of these equations is a broad and very active field of mathematical research.
Some types of tidal bore, a wave phenomenon of a few rivers including the River Severn, are undular: a wavefront followed by a train of solitons. Other solitons occur as the undersea internal waves, initiated by seabed topography, that propagate on the oceanic pycnocline. Atmospheric solitons also exist, such as the morning glory cloud of the Gulf of Carpentaria, where pressure solitons traveling in a temperature inversion layer produce vast linear roll clouds. The recent and not widely accepted soliton model in neuroscience proposes to explain the signal conduction within neurons as pressure solitons.
A topological soliton, also called a topological defect, is any solution of a set of partial differential equations that is stable against decay to the "trivial solution". Soliton stability is due to topological constraints, rather than integrability of the field equations. The constraints arise almost always because the differential equations must obey a set of boundary conditions, and the boundary has a nontrivial homotopy group, preserved by the differential equations. Thus, the differential equation solutions can be classified into homotopy classes.
No continuous transformation maps a solution in one homotopy class to another. The solutions are truly distinct, and maintain their integrity, even in the face of extremely powerful forces. Examples of topological solitons include the screw dislocation in a crystalline lattice, the Dirac string and the magnetic monopole in electromagnetism, the Skyrmion and the Wess–Zumino–Witten model in quantum field theory, the magnetic skyrmion in condensed matter physics, and cosmic strings and domain walls in cosmology. | 1 | Applied and Interdisciplinary Chemistry |
The following equation can be used to correct a measured pollutant concentration in an emitted gas (containing a measured O content) to an equivalent pollutant concentration in an emitted gas containing a specified reference amount of O:
Thus, a measured concentration of 45 ppmv (dry basis) in a gas having 5 volume % O is<br>
45 × ( 20.9 - 3 ) ÷ ( 20.9 - 5 ) = 50.7 ppmv (dry basis) of when corrected to a gas having a specified reference O content of 3 volume %. | 1 | Applied and Interdisciplinary Chemistry |
There are several kinds of wastewater which are treated at the appropriate type of treatment plant. Domestic wastewater (also called municipal wastewater or sewage) is processed at a sewage treatment plant. For industrial wastewater, treatment either takes place in a separate industrial wastewater treatment facility, or in a sewage treatment plant (usually after some form of pre-treatment). Other types of wastewater treatment plants include agricultural wastewater treatment and leachate treatment plants.
Treating wastewater efficiently is challenging, but improved technology allows for enhanced removal of specific materials, increased re-use of water, and energy production from waste. | 1 | Applied and Interdisciplinary Chemistry |
Wetlands are areas of land submerged in water near both terrestrial and aquatic systems. They are highly diverse and are classified by the United States Fish and Wildlife Service into five categories: “The term wetland includes a variety of areas that fall into one of five categories: (1) areas with hydrophytes and hydric soils, such as those commonly known as marshes, swamps, and bogs; (2) areas without hydrophytes but with hydric soils - for example, flats where drastic fluctuation in water level, wave action, turbidity, or high concentration of salts may prevent the growth of hydrophytes; (3) areas with hydrophytes but nonhydric soils, such as margins of impoundments or excavations where hydrophytes have become established but hydric soils have not yet developed; (4) areas without soils but with hydrophytes such as the seaweed-covered portion of rocky shores; and (5) wetlands without soil and without hydrophytes, such as gravel beaches or rocky shores without vegetation”.
Wetlands can also be classified based on salinity, a type of classification often referenced in research where salinity is a major factor. These classifications are often referred to in parts per thousand (ppt) and include freshwater (0-2 ppt), intermediate (2-10 ppt), brackish (10-20 ppt), and saltwater (20+ ppt). | 0 | Theoretical and Fundamental Chemistry |
[F]Fluorodeoxyglucose (INN), or fluorodeoxyglucose F 18 (USAN and USP), also commonly called fluorodeoxyglucose and abbreviated [F]FDG, 2-[F]FDG or FDG, is a radiopharmaceutical, specifically a radiotracer, used in the medical imaging modality positron emission tomography (PET). Chemically, it is 2-deoxy-2-[F]fluoro--glucose, a glucose analog, with the positron-emitting radionuclide fluorine-18 substituted for the normal hydroxyl group at the C-2 position in the glucose molecule.
The uptake of [F]FDG by tissues is a marker for the tissue uptake of glucose, which in turn is closely correlated with certain types of tissue metabolism. After [F]FDG is injected into a patient, a PET scanner can form two-dimensional or three-dimensional images of the distribution of [F]FDG within the body.
Since its development in 1976, [F]FDG had a profound influence on research in the neurosciences. The subsequent discovery in 1980 that [F]FDG accumulates in tumors underpins the evolution of PET as a major clinical tool in cancer diagnosis. [F]FDG is now the standard radiotracer used for PET neuroimaging and cancer patient management.
The images can be assessed by a nuclear medicine physician or radiologist to provide diagnoses of various medical conditions. | 1 | Applied and Interdisciplinary Chemistry |
Although the phenomenologies of the superfluid states of helium-4 and helium-3 are very similar, the microscopic details of the transitions are very different. Helium-4 atoms are bosons, and their superfluidity can be understood in terms of the Bose–Einstein statistics that they obey. Specifically, the superfluidity of helium-4 can be regarded as a consequence of Bose–Einstein condensation in an interacting system. On the other hand, helium-3 atoms are fermions, and the superfluid transition in this system is described by a generalization of the BCS theory of superconductivity. In it, Cooper pairing takes place between atoms rather than electrons, and the attractive interaction between them is mediated by spin fluctuations rather than phonons. (See fermion condensate.) A unified description of superconductivity and superfluidity is possible in terms of gauge symmetry breaking. | 1 | Applied and Interdisciplinary Chemistry |
In chemistry, an ideal solution or ideal mixture is a solution that exhibits thermodynamic properties analogous to those of a mixture of ideal gases. The enthalpy of mixing is zero as is the volume change on mixing by definition; the closer to zero the enthalpy of mixing is, the more "ideal" the behavior of the solution becomes. The vapor pressures of the solvent and solute obey Raoults law and Henrys law, respectively, and the activity coefficient (which measures deviation from ideality) is equal to one for each component.
The concept of an ideal solution is fundamental to chemical thermodynamics and its applications, such as the explanation of colligative properties. | 0 | Theoretical and Fundamental Chemistry |
Vanadates exhibit a variety of biological activities, in part because they serve as structural mimics of phosphates. It acts as a competitive inhibitor of ATPases, alkaline and acid phosphatases, and protein-phosphotyrosine phosphatases, and its inhibitory effects can be reversed by dilution or the addition of ethylenediaminetetraacetic acid (EDTA).
Orthovanadate is activated by boiling and adjusting pH to ~10; this depolymerizes decavanadate into the active inhibitor, monovanadate. | 0 | Theoretical and Fundamental Chemistry |
The sodium fusion extract is acidified with acetic acid and lead acetate is added to it. A black precipitate of lead sulfide indicates the presence of sulfur. | 0 | Theoretical and Fundamental Chemistry |
In Mexico, modafinil is not listed as a controlled substance, in the National Health Law, and can be purchased in pharmacies without prescription. | 0 | Theoretical and Fundamental Chemistry |
The Sepro Blackhawk 100 Cone Crusher is a modern, hydraulically operated cone crusher designed to be simple, rugged and effective for heavy duty mining and aggregate applications. The combination of the speed and eccentric throw of the crusher provides fine crushing capability and high capacity in a very compact design. The Blackhawk is capable of being applied as a secondary or tertiary crusher as well as a pebble crusher. The Blackhawk 100 is driven directly via a flexible coupling to the electric drive motor. This arrangement eliminates the need for sheaves and v-belts, allowing for simplified operation and maintenance. A variable speed drive package is included to optimize the speed of the machine to the given liner profile, feed and production conditions. | 1 | Applied and Interdisciplinary Chemistry |
Amine oxides (AO) are not known to be carcinogens, dermal sensitizers, or reproductive toxicants. They are readily metabolized and excreted if ingested. Chronic ingestion by rabbits found lower body weight, diarrhea, and lenticular opacities at a lowest observed adverse effect levels (LOAEL) in the range of 87–150 mg AO/kw bw/day. Tests of human skin exposure have found that after 8 hours less than 1% is absorbed into the body. Eye irritation due to amine oxides and other surfactants is moderate and temporary with no lasting effects. | 0 | Theoretical and Fundamental Chemistry |
The G protein-coupled receptor is activated by an external signal in the form of a ligand or other signal mediator. This creates a conformational change in the receptor, causing activation of a G protein. Further effect depends on the type of G protein. G proteins are subsequently inactivated by GTPase activating proteins, known as RGS proteins. | 1 | Applied and Interdisciplinary Chemistry |
There is a pressure difference between the outside air and the air inside the building caused by the difference in temperature between the outside air and the inside air. That pressure difference ( ΔP ) is the driving force for the stack effect and it can be calculated with the equations presented below. The equations apply only to buildings where air is both inside and outside the buildings. For buildings with one or two floors, h is the height of the building. For multi-floor, high-rise buildings, h is the distance from the openings at the neutral pressure level (NPL) of the building to either the topmost openings or the lowest openings. Reference explains how the NPL affects the stack effect in high-rise buildings.
For flue gas stacks and chimneys, where air is on the outside and combustion flue gases are on the inside, the equations will only provide an approximation and h is the height of the flue gas stack or chimney.
:SI units:
:U.S. customary units: | 0 | Theoretical and Fundamental Chemistry |
This experiment provides correlations between a carbon and its attached protons. The constant time (CT) version of H—C HSQC is normally used as it circumvents the issue of splitting of signal due to homonuclear C—C J couplings which reduces spectral resolution. The "constant time" refers to the entire evolution period between the two INEPT steps which is kept constant in this experiment. If this evolution period is set to be the inverse of the J-coupling constant, then the sign of the magnetization of those carbons with an odd number of aliphatic carbon attached will be opposite to those with an even number. For example, if the C of leucine appears as a positive peak (2 aliphatic carbons attached), then the C (3 aliphatic carbons attached) and C (1 aliphatic carbons attached) would appear negative. | 0 | Theoretical and Fundamental Chemistry |
The following peptides were synthesized using this method by 1949: <br/>
* -Ala-Gly
* -Tyr-Gly
* -Tyr-Tyr
* -Ala--Ala-Gly
* -di-Ala--cystinyl-di-Gly
* -Ala--Tyr-Gly
* -Ala--Tyr-Gly-Gly
* -Ala--Ala-L-Tyr-Gly-Gly
* -Tyr--Tyr--Tyr
* -Cystinyl-di-Gly | 1 | Applied and Interdisciplinary Chemistry |
# Water Conservation: A newly constructed home can implement products with the WaterSense label at no additional costs and achieve a water savings of 20% when including the water heater savings and the water itself.
# Energy Conservation: Energy conservation is highly intensive when it comes to cost premiums for implementation. However, it also has large potential for savings. Minimum savings can be achieved at no additional cost by pursuing passive design strategies. The next step up from passive design in the level of green (and ultimately the level of savings) would be implementing advanced building envelopematerials, like structural insulated panels (SIPs). SIPs can be installed for approximately $2 per linear foot of exterior wall. That equals a total premium of less than $500 for a typical one-story home, which will bring an energy savings of 50%. According to the DOE, the average annual energy expense for a single family home is $2,200. So SIPs can save up to $1,100 per year. To reach the savings associated with a net-zero energy home, renewable energy would have to be implemented on top of the other features. A geothermal energy system could achieve this goal with a cost premium of approximately $7 per square foot, while a photovoltaic system (solar) would require up to a $25,000 total premium. | 1 | Applied and Interdisciplinary Chemistry |
The biochemistry of methanogenesis involves the following coenzymes and cofactors: F420, coenzyme B, coenzyme M, methanofuran, and methanopterin.
The mechanism for the conversion of bond into methane involves a ternary complex of methyl coenzyme M and coenzyme B fit into a channel terminated by the axial site on nickel of the cofactor F430. One proposed mechanism invokes electron transfer from Ni(I) (to give Ni(II)), which initiates formation of . Coupling of the coenzyme M thiyl radical (RS) with HS coenzyme B releases a proton and re-reduces Ni(II) by one-electron, regenerating Ni(I). | 1 | Applied and Interdisciplinary Chemistry |
Mafic magma dominated the seafloor at around 3.9 Ga during the Hadean-Archean transition. Due to rapid silicification, the felsic continental crust began to form. In the Archean, the continental crust was composed of tonalite–trondhjemite–granodiorite (TTG) as well as granite–monzonite–syenite suites.
The Mount Goldsworthy in the Pilbara Craton located in Western Australia holds one of the earliest silicification example with an Archean clastic meta-sedimentary rock sequence, revealing the surface environment of the Earth in the early times with evidence from silicification and hydrothermal alteration. The unearthed rocks are found to be SiO2 dominant in terms of mineral composition. The succession was subjected to a high degree of silicification due to hydrothermal interaction with seawater at low temperatures. Lithic fragments were replaced with microcrystalline quartz and protoliths were altered during silicification. The condition of silicification and the elements that were present suggested that the surface temperature and carbon dioxide contents were high during either or both syn-deposition and post-deposition.
The Barberton Greenstone Belt in South Africa, specifically the Eswatini Supergroup of around 3.5–3.2 Ga, is a suite of well-preserved silicified volcanic-sedimentary rocks. With the composition ranging from ultramafic to felsic, the silicified volcanic rocks are directly beneath the bedded chert layer. Rocks are more silicified near the bedded chert contact, suggesting a relationship between chert deposition and silicification. The silica altered zones reveal that hydrothermal activities, as in seawater circulation, actively circulate the rock layers through fractures and fault during the deposition of bedded chert. The seawater was heated up and therefore picked up silicious materials from underneath volcanic origin. The silica enriched fluids bring about silicification of rocks through seeping into porous materials in the syn-depositional stage at a low-temperature condition. | 0 | Theoretical and Fundamental Chemistry |
A polymer brush is the name given to a surface coating consisting of polymers tethered to a surface. The brush may be either in a solvated state, where the tethered polymer layer consists of polymer and solvent, or in a melt state, where the tethered chains completely fill up the space available. These polymer layers can be tethered to flat substrates such as silicon wafers, or highly curved substrates such as nanoparticles. Also, polymers can be tethered in high density to another single polymer chain, although this arrangement is normally named a bottle brush. Additionally, there is a separate class of polyelectrolyte brushes, when the polymer chains themselves carry an electrostatic charge.
The brushes are often characterized by the high density of grafted chains. The limited space then leads to a strong extension of the chains. Brushes can be used to stabilize colloids, reduce friction between surfaces, and to provide lubrication in artificial joints.
Polymer brushes have been modeled with Molecular Dynamics, Monte Carlo methods, Brownian dynamics simulations, and molecular theories. | 0 | Theoretical and Fundamental Chemistry |
Hans Spemann, a German embryologist was awarded a Nobel Prize in Physiology or Medicine in 1935 for his discovery of the effect now known as embryonic induction, exercised by various parts of the embryo, that directs the development of groups of cells into particular tissues and organs. In 1924 he and his student, Hilde Mangold, were the first to perform somatic-cell nuclear transfer using amphibian embryos – one of the first steps towards cloning. | 1 | Applied and Interdisciplinary Chemistry |
pVIII is the main coat protein of Ff phages. Peptides are usually fused to the N-terminus of pVIII. Usually peptides that can be fused to pVIII are 6-8 amino acids long. The size restriction seems to have less to do with structural impediment caused by the added section and more to do with the size exclusion caused by pIV during coat protein export. Since there are around 2700 copies of the protein on a typical phages, it is more likely that the protein of interest will be expressed polyvalently even if a phagemid is used. This makes the use of this protein unfavorable for the discovery of high affinity binding partners.
To overcome the size problem of pVIII, artificial coat proteins have been designed. An example is Weiss and Sidhus inverted artificial coat protein (ACP) which allows the display of large proteins at the C-terminus. The ACPs could display a protein of 20kDa, however, only at low levels (mostly only monovalently). | 1 | Applied and Interdisciplinary Chemistry |
DNA-encoded chemical libraries (DECL) is a technology for the synthesis and screening on an unprecedented scale of collections of small molecule compounds. DECL is used in medicinal chemistry to bridge the fields of combinatorial chemistry and molecular biology. The aim of DECL technology is to accelerate the drug discovery process and in particular early phase discovery activities such as target validation and hit identification.
DECL technology involves the conjugation of chemical compounds or building blocks to short DNA fragments that serve as identification bar codes and in some cases also direct and control the chemical synthesis. The technique enables the mass creation and interrogation of libraries via affinity selection, typically on an immobilized protein target. A homogeneous method for screening DNA-encoded libraries (DELs) has recently been developed which uses water-in-oil emulsion technology to isolate, count and identify individual ligand-target complexes in a single-tube approach. In contrast to conventional screening procedures such as high-throughput screening, biochemical assays are not required for binder identification, in principle allowing the isolation of binders to a wide range of proteins historically difficult to tackle with conventional screening technologies. So, in addition to the general discovery of target specific molecular compounds, the availability of binders to pharmacologically important, but so-far “undruggable” target proteins opens new possibilities to develop novel drugs for diseases that could not be treated so far. In eliminating the requirement to initially assess the activity of hits it is hoped and expected that many of the high affinity binders identified will be shown to be active in independent analysis of selected hits, therefore offering an efficient method to identify high quality hits and pharmaceutical leads. | 1 | Applied and Interdisciplinary Chemistry |
PEA, as an N-acylethanolamine, has physico-chemical properties comparable to anandamide, and, while it is not strictly an endocannabinoid, it is often studied in conjunction with anandamide because of their overlapping synthetic and metabolic pathways. N-acylethanolamines such as PEA often act as signaling molecules, activating receptors and regulating a variety of physiological functions. PEA is known to activate intracellular, nuclear and membrane-associated receptors, and to regulate many physiological functions related to the inflammatory cascade and chronic pain states. Endocannabinoid lipids like PEA are widely distributed in nature, in a variety of plant, invertebrate, and mammalian tissues.
PEAs mechanism of action sometimes is described as Autacoid Local Injury Antagonism (acronym ALIA), and PEA under this nomenclature is an ALIAmide. Levi-Montalcini and coworkers presented evidence in 1993 that lipid amides of the N-acylethanolamine type, such as PEA, are potential prototypes of naturally occurring molecules capable of modulating mast cell activation, and her group used the acronym ALIA in that report. An autocoid is a regulating molecule, locally produced. An ALIAmide is an autocoid synthesized on-demand in response to injury, and acts locally to counteract such pathology. Soon after the breakthrough paper of Levi-Montalcini, the mast cell appeared to be an important target for the anti-inflammatory activity of PEA. Since 1993, at least 25 papers have been published on the various effects of PEA on mast cells. These cells are often found in proximity to sensory nerve endings, and their degranulation can enhance the nociceptive signal, the reason why peripheral mast cells are considered to be pro-inflammatory and pro-nociceptive. PEAs activity is currently seen as a new inroad in the treatment of neuropathic pain and related disorders based on overactivation of glia and glia-related cells, such as in diabetes and glaucoma. Microglia plays a key role in the winding up phenomenon and central sensitization. | 1 | Applied and Interdisciplinary Chemistry |
In terms of inhibitors of intrinsic termination, much is still unknown. One of the few examples that is known is bacteriophage protein 7. This is made up of 3.4A and 4.0A cryo-EM structures of P7-NusA-TEC and P7-TEC. This bacteriophage protein 7 stops transcription termination by blocking the RNA polymerase (RNAP) RNA-exit channel and impeding RNA-hairpin formation at the intrinsic terminator. Furthermore, bacteriophage protein 7 inhibits RNAP-clamp motions. Shortening the C-terminal half-helix of the RNAP slightly decreases the inhibitory activity. These RNAP clamp motions have been targeted by some other inhibitors of bacterial RNAP. These inhibitors include myxopyronin, corallopyronin, and ripostatin. These work by inhibiting isomerization. | 1 | Applied and Interdisciplinary Chemistry |
Genetic significant dose (GSD), or genetically significant dose, was initially defined by United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) in 1958.
It represents an estimate of the genetic significance of gonad radiation doses. Annual GSD is calculated by weighting the individual gonad doses received during ionizing imaging by the number of individual examined, and accounting for the number of offspring for each individual. | 0 | Theoretical and Fundamental Chemistry |
Tardigrade specific proteins are types of intrinsically disordered proteins specific to tardigrades. These proteins help tardigrades survive desiccation, one of the adaptations which contribute to tardigrade's extremotolerant nature. Tardigrade specific proteins are strongly influenced by their environment, leading to adaptive malleability across a variety of extreme abiotic environments. | 1 | Applied and Interdisciplinary Chemistry |
A glycosyl acceptor is any suitable nucleophile-containing molecule that will react with a glycosyl donor to form a new glycosidic bond. By convention, the acceptor is the member of this pair which did not contain the resulting anomeric carbon of the new glycosidic bond. Since the nucleophilic atom of the acceptor is typically an oxygen atom, this can be remembered using the mnemonic of the acceptor is the alcohol. A glycosyl acceptor can be a mono- or oligosaccharide that contains an available nucleophile, such as an unprotected hydroxyl. | 0 | Theoretical and Fundamental Chemistry |
A number of different structural domains that fold mostly on their own have been found in the APP sequence. The extracellular region, much larger than the intracellular region, is divided into the E1 and E2 domains, linked by an acidic domain (AcD); E1 contains two subdomains including a growth factor-like domain (GFLD) and a copper-binding domain (CuBD) interacting tightly together. A serine protease inhibitor domain, absent from the isoform differentially expressed in the brain, is found between acidic region and E2 domain. The complete crystal structure of APP has not yet been solved; however, individual domains have been successfully crystallized, the growth factor-like domain, the copper-binding domain, the complete E1 domain and the E2 domain. | 1 | Applied and Interdisciplinary Chemistry |
Light detectors, such as photographic plates or CCDs, measure only the intensity of the light that hits them. This measurement is incomplete (even when neglecting other degrees of freedom such as polarization and angle of incidence) because a light wave has not only an amplitude (related to the intensity), but also a phase (related to the direction), and polarization which are systematically lost in a measurement. In diffraction or microscopy experiments, the phase part of the wave often contains valuable information on the studied specimen. The phase problem constitutes a fundamental limitation ultimately related to the nature of measurement in quantum mechanics.
In X-ray crystallography, the diffraction data when properly assembled gives the amplitude of the 3D Fourier transform of the molecule's electron density in the unit cell. If the phases are known, the electron density can be simply obtained by Fourier synthesis. This Fourier transform relation also holds for two-dimensional far-field diffraction patterns (also called Fraunhofer diffraction) giving rise to a similar type of phase problem. | 0 | Theoretical and Fundamental Chemistry |
NMOR is generally not used intentionally, but is instead created by the nitrosation of morpholine or morpholine derivatives which are used for several industrial purposes. | 0 | Theoretical and Fundamental Chemistry |
All chromatographic purifications and separations which are executed via solvent gradient batch chromatography can be performed using MCSGP. Typical examples are reversed phase purification of peptides, hydrophobic interaction chromatography for fatty acids or for example ion exchange chromatography of proteins or antibodies. The process can effectively enrich components, which have been fed in only small amounts. Continuous capturing of antibodies without affinity chromatography can be realized with the MCSGP-process. | 0 | Theoretical and Fundamental Chemistry |
In many non-Newtonian fluids, the shear stress due to viscosity, , can be modeled by
where
* k is the consistency index
* n is the flow behavior index
* du/dy is the shear rate, with velocity u and position y
These fluids are called power-law fluids.
To ensure that has the same sign as du/dy, this is often written as
where the term
gives the apparent viscosity. | 1 | Applied and Interdisciplinary Chemistry |
The silicon α‑effect described above is mainly focused on carbon. In fact, the most industrially-important silicon α‑effect instead occurs with silyl ethers. Under hydrolysis condition, certain α-silane-terminated prepolymers crosslink 10-1000 times faster than the corresponding prepolymers produced from conventional C-functionalized trialkoxypropylsilanes and dialkoxymethylpropylsilanes. | 0 | Theoretical and Fundamental Chemistry |
George Simms Hammond (May 22, 1921 – October 5, 2005) was an American scientist and theoretical chemist who developed "Hammonds postulate", and fathered organic photochemistry,–the general theory of the geometric structure of the transition state in an organic chemical reaction. Hammonds research is also known for its influence on the philosophy of science. His research garnered him the Norris Award in 1968, the Priestley Medal in 1976, the National Medal of Science in 1994, and the Othmer Gold Medal in 2003. He served as the executive chairman of the Allied Chemical Corporation from 1979 to 1989.
He was a chemist at the California Institute of Technology, and subsequently headed both the Departments of Chemistry and Chemical Engineering at the university. He conducted research at the University of Oxford and University of Basel as a Guggenheim Fellow and National Science Foundation Fellow, respectively. He served as the foreign secretary of the National Academy of Sciences from 1974 to 1978.
A native of Maine, he was born and raised in Auburn; he attended nearby Bates College in Lewiston, Maine, where he graduated magna cum laude with a B.S. in chemistry in 1943. He completed his doctorate at Harvard University in 1947, under the mentorship of Paul Doughty Bartlett, and a postdoctorate at University of California, Los Angeles with Saul Winstein in 1948. | 0 | Theoretical and Fundamental Chemistry |
Tertiary phosphine oxides, compounds with the formula RPO cannot tautomerize. The situation is different for the secondary and primary phosphine oxides, with the respective formulas R(H)PO and R(H)PO. | 0 | Theoretical and Fundamental Chemistry |
Natural gas that carries a lot of liquids with it is known as wet gas whereas natural gas that is produced without liquid is known dry gas. Dry gas is also treated as to remove all liquids. The effect of flow conditioning for various popular meters which is used in gas measurement is explained below. | 1 | Applied and Interdisciplinary Chemistry |
Malonyl-CoA signals glucose utilization and it controls the entry and oxidation of long-chain fatty acids (LCFA) in the mitochondria. Circulating glucose in the liver stimulates its uptake. Glucose oxidation produces citrate which can be converted to malonyl-CoA by acetyl-CoA carboxylase. Malonyl-CoA inhibits the carnitine palmitoyltransferase (CPT) that controls the entry and oxidation of LCFA. The glucose-derived malonyl-CoA prevents the oxidation of fatty acids and favors fatty acid esterification. | 1 | Applied and Interdisciplinary Chemistry |
N NMR is also extremely valuable in protein NMR investigations. Most notably, the introduction of three-dimensional experiments with N lifts the ambiguity in C–C two-dimensional experiments. In solid-state nuclear magnetic resonance (ssNMR), for example, N is most commonly utilized in NCACX, NCOCX, and CANcoCX pulse sequences. | 0 | Theoretical and Fundamental Chemistry |
Tungsten is the most common refractory metal that can be used as a selective emitter. It has higher emissivity in the visible and near-IR range of 0.45 to 0.47 and a low emissivity of 0.1 to 0.2 in the IR region. The emitter is usually in the shape of a cylinder with a sealed bottom, which can be considered a cavity. The emitter is attached to the back of a thermal absorber such as SiC and maintains the same temperature. Emission occurs in the visible and near IR range, which can be readily converted by the PV to electrical energy. However, compared to other metals, tungsten oxidizes more easily. | 0 | Theoretical and Fundamental Chemistry |
Highly favourable binding of a substrate at a non-reactive site will force the reactive site of the substrate to be more reactive by putting it in a very unfavourable position. This effect was observed in orotidine 5‘-phosphate decarboxylase. This can occur by positioning a charged amino acid group next to the charged substrate thus destabilizing it, thus making the reaction occur faster. Furthermore, the substrate is put into an optimal position by the enzyme for the reaction to occur, thus decreasing the entropy greatly.
A corollary of the effect is to explain the existence of one-way enzymes that are much more effective catalysts for one direction of reaction than the other. For example, the limiting rate in the forward direction of the reaction catalyzed by methionine adenosyltransferase is about 2 × 10 times higher than it is for the reverse reaction. This concept is frequently misunderstood: it does not imply any violation of thermodynamic principles. It is a kinetic effect, not a thermodynamic one, and the reaction always proceeds toward equilibrium, regardless of where the process starts. And when it is at equilibrium the rate is always zero. | 1 | Applied and Interdisciplinary Chemistry |
The threat of acidification includes a decline in commercial fisheries and the coast-based tourism industry. Several ocean goods and services are likely to be undermined by future ocean acidification potentially affecting the livelihoods of some 400 to 800 million people, depending upon the greenhouse gas emission scenario.
Some 1 billion people are wholly or partially dependent on the fishing, tourism, and coastal management services provided by coral reefs. Ongoing acidification of the oceans may therefore threaten future food chains linked with the oceans. | 0 | Theoretical and Fundamental Chemistry |
Pdr1p is a main regulator of PDR genes and is known to target about 50 genes. Pdr1p binds to sequence 5-TCCGYGGR-3 of PDRE, which is located within the promoter sequences of its target genes. 218 genes are reported to possess PDRE. Pdr1p is observed to bind PDRE sites on DNA at basal level and also after simulation with toxins. This shows that Pdr1p-DNA interaction isnt dependent on toxic stimulation. This also suggests an involvement of activator(s) or co-activator(s) that induce PDR genes along with Pdr1p. Pdr1p has a functional homolog called Pdr3p encoded by gene called PDR3'. Pdr3p is known to be regulated by Pdr3p and Pdr1p. Pdr1p can form a homodimer with itself or heterodimer with Pdr3p.
Loss of function studies of both PDR1 and PDR3 revealed that Pdr1p mutant shows lower tolerance (grows less in culture) against organic toxins such as cycloheximide and oligomycin. This confirms the functions of Prf1p that confer stronger drug response phenotype than Pdr3p. However, Pdr3p is crucial for PDR responses since cells containing loss of function mutation in both PDR1 and PDR3 genes weren't able to grow at all in the presence of those two toxins.
Both Pdr1p and Pdr3p regulate Pdr5p, which is an ATP-binding cassette transporter. A single amino acid substitution mutation, which is a gain of function mutation of Pdr1p denoted as pdr1-3 (F815S, substitution mutation of Phenylalanine at 815th of the polypeptide by Serine) leads to an over-expression of mRNA of PDR5, which codes for Pdr5p. For cells treated with fluphenazine, Pdr1p was the only transcription factor necessary for PDR response genes induction. But at basal level, Pdr1p can be partially compensated by Pdr3p, a functional homolog of Pdr1p. | 1 | Applied and Interdisciplinary Chemistry |
F-gases are ozone-friendly, enable energy efficiency, and are relatively safe for use by the public due to their low levels of toxicity and flammability. However, most F-gases have a high global warming potential (GWP), and some are nearly inert to removal by chemical processes. If released, HFCs stay in the atmosphere for decades and both PFCs and SF can stay in the atmosphere for millennia.
The total atmospheric concentration of F-gases, CFCs, and HCFCs has grown rapidly since the mid-twentieth century; a time which marks the start of their production and use at industrial scale. As a group in year 2019, these unnatural man-made gases are responsible for about one-tenth of the direct radiative forcing from all long-lived anthropogenic greenhouse gases.
F-gases are used in a number of applications intended for climate change mitigation, that can generate further positive feedback for atmospheric heating. For example, refrigeration and air conditioning systems are increasingly utilized by humans within a warming environment. Likewise, expansions of electrical infrastructure, as driven by the alternatives to fossil fuels, has led to rising demand for SF. If recent trends of aggressive (5% and greater CAGR) annual growth for such types of F-gas production were to continue into the future without complimentary reductions in GWP and/or atmospheric leakage, their warming influence could soon rival those of CO and CH which are trending at less than about 2% annual growth. | 1 | Applied and Interdisciplinary Chemistry |
Markovnikov married Lyubov Dmitrievna Rychkova. They had two sons, Vladimir, a politician and Nikolai, an architect. | 0 | Theoretical and Fundamental Chemistry |
Another type of isomerism based on nuclear properties is spin isomerism, where molecules differ only in the relative spin magnetic quantum numbers m of the constituent atomic nuclei. This phenomenon is significant for molecular hydrogen, which can be partially separated into two long-lived states described as spin isomers or nuclear spin isomers: parahydrogen, with the spins of the two nuclei pointing in opposite directions, and orthohydrogen, where the spins point in the same direction. | 0 | Theoretical and Fundamental Chemistry |
A nonsynonymous substitution is a nucleotide mutation that alters the amino acid sequence of a protein. Nonsynonymous substitutions differ from synonymous substitutions, which do not alter amino acid sequences and are (sometimes) silent mutations. As nonsynonymous substitutions result in a biological change in the organism, they are subject to natural selection.
Nonsynonymous substitutions at a certain locus can be compared to the synonymous substitutions at the same locus to obtain the K/K ratio. This ratio is used to measure the evolutionary rate of gene sequences. If a gene has lower levels of nonsynonymous than synonymous nucleotide substitution, then it can be inferred to be functional because a K/K ratio < 1 is a hallmark of sequences that are being constrained to code for proteins.
Nonsynonymous substitutions are also referred to as replacement mutations. | 1 | Applied and Interdisciplinary Chemistry |
While kinematical diffraction is adequate to understand the geometry of the diffraction spots, it does not correctly give the intensities and has a number of other limitations. For a more complete approach one has to include multiple scattering of the electrons using methods that date back to the early work of Hans Bethe in 1928. These are based around solutions of the Schrödinger equation using the relativistic effective mass described earlier. Even at very high energies dynamical diffraction is needed as the relativistic mass and wavelength partially cancel, so the role of the potential is larger than might be thought.
The main components of current dynamical diffraction of electrons include:
* Taking into account the scattering back into the incident beam both from diffracted beams and between all others, not just single scattering from the incident beam to diffracted beams. This is important even for samples which are only a few atoms thick.
* Modelling at least semi-empirically the role of inelastic scattering by an imaginary component of the potential, also called an "optical potential". There is always inelastic scattering, and often it can have a major effect on both the background and sometimes the details, see Figure 7 and 18.
* Higher-order numerical approaches to calculate the intensities such as multislice, matrix methods which are called Bloch-wave approaches or muffin-tin approaches. With these diffraction spots which are not present in kinematical theory can be present, e.g.
* Contributions to the diffraction from elastic strain and crystallographic defects, and also what Jens Lindhard called the string potential.
* For transmission electron microscopes effects due to variations in the thickness of the sample and the normal to the surface.
* Both in the geometry of scattering and calculations, for both LEED and RHEED, effects due to the presence of surface steps, surface reconstructions and other atoms at the surface. Often these change the diffraction details significantly.
* For LEED, use more careful analyses of the potential because contributions from exchange terms can be important. Without these the calculations may not be accurate enough. | 0 | Theoretical and Fundamental Chemistry |
The British Pharmacopoeia is published on behalf of the Health Ministers of the United Kingdom; on the recommendation of the Commission on Human Medicines, in accordance with section 99(6) of the Medicines Act 1968, and notified in draft to the European Commission (EC) in accordance with Directive 98/34/EEC.
The monographs of the European Pharmacopoeia (as amended by Supplements published by the Council of Europe) are reproduced either in the British Pharmacopoeia, or in the associated edition of the British Pharmacopoeia (Veterinary).
In the pharmacopoeia, certain drugs and preparations are included regardless of the existence of actual or potential patent rights. Where substances are protected by letters patent, their inclusion in the pharmacopoeia neither conveys, nor implies, licence to manufacture. | 1 | Applied and Interdisciplinary Chemistry |
Trans-regulatory elements (TRE) are DNA sequences encoding upstream regulators (ie. trans-acting factors), which may modify or regulate the expression of distant genes. Trans-acting factors interact with cis-regulatory elements to regulate gene expression. TRE mediates expression profiles of a large number of genes via trans-acting factors. While TRE mutations affect gene expression, it is also one of the main driving factors for evolutionary divergence in gene expression. | 1 | Applied and Interdisciplinary Chemistry |
A mixed-waste processing system, sometimes referred to as a dirty MRF, accepts a mixed solid waste stream and then proceeds to separate out designated recyclable materials through a combination of manual and mechanical sorting. The sorted recyclable materials may undergo further processing required to meet technical specifications established by end-markets while the balance of the mixed waste stream is sent to a disposal facility such as a landfill. Today, MWPFs are attracting renewed interest as a way to address low participation rates for source-separated recycling collection systems and prepare fuel products and/or feedstocks for conversion technologies. MWPFs can give communities the opportunity to recycle at much higher rates than has been demonstrated by curbside or other waste collection systems. Advances in technology make today’s MWPF different and, in many respects better, than older versions. | 1 | Applied and Interdisciplinary Chemistry |
The IAGC (International Association of GeoChemistry, formerly known as the International Association of Geochemistry and Cosmochemistry) is affiliated with the International Union of Geological Sciences and has been one of the pre-eminent international geochemical organizations for over thirty-five years.
The principal objective of the IAGC is to foster co-operation in, and advancement of, geochemistry in the broadest sense. This is achieved by:
# working with any interested group in planning symposia and other types of meetings related to geochemistry,
# sponsoring publications in geochemistry of a type not normally covered by existing organizations and,
# the activities of working groups which study problems that require, or would benefit from, international co-operation.
The scientific thrust of the IAGC takes place through its Working Groups (many of which organize regular symposia) and the official journal, Applied Geochemistry.
The specific objectives of the IAGC are:
# To foster the use of the tools and techniques of chemistry to advance the understanding of the earth and its component systems for the benefit of mankind and modern society;
# To contribute to advancement in geochemical research throughout the world, including both fundamental geochemical research aimed at understanding the global earth system and applied geochemical research that addresses problems of particular relevance to the welfare of mankind and society;
# To promote international and education cooperation in geochemistry through outreach activities that include:
#* establishing internal specialty-area working groups in topic areas that would benefit from international scientific cooperation,
#* sponsoring international scientific meetings related to geochemistry,
#* disseminating new knowledge through publication of the journal “Applied Geochemistry,”
#* fostering communication in geochemistry across the international scientific community,
#* encouraging the early career development of young geochemists,
#* contributing to geochemical education,
#* enhancing the visibility of the science of geochemistry and demonstrating its importance to mankind and society. | 0 | Theoretical and Fundamental Chemistry |
PI3K inhibitors may overcome drug resistance and improve advanced breast cancer (ABC) outcomes. Different PI3K inhibitors exhibit different effect against various PI3K types. Class IA pan-PI3K inhibitors have been more extensively studied than isoform specific inhibitors; Pictilisib is another pan-PI3K inhibitor with greater subunitα-inhibitor activity than buparlisib. Idelalisib is the first PI3K inhibitor approved by the US Food and Drug Administration and is utilized in the treatment of relapsed/refractory chronic lymphocytic leukemia/small lymphocytic lymphoma and follicular lymphoma. Copanlisib is approved for relapsed follicular lymphoma in patients who have received at least two prior systemic therapies. Duvelisib is approved for relapsed/refractory chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL), and relapsed/refractory follicular lymphoma, both indications for patients who have received at least two prior therapies. | 1 | Applied and Interdisciplinary Chemistry |
The use of iodine-containing solutions as an aid to describing and identifying fungi dates back to the mid-19th century.
Melzers reagent was first described in 1924 and takes its name from its inventor, the mycologist Václav Melzer, who modified an older chloral hydrate-containing IKI solution developed by botanist Arthur Meyer. Melzer was a specialist in Russula', a genus in which the amyloidy on the spore ornamentation or entire spore is of great taxonomic significance. | 0 | Theoretical and Fundamental Chemistry |
The first (non-exhaustive) inventory of microorganisms with a documented history of use in food was for the first time compiled in 2001 by the [http://www.fil-idf.org International Dairy Federation (IDF)] and the [http://www.effca.org European Food and Feed Cultures Association (EFFCA)].
In 2012, this inventory was updated. It now covers a wide range of food applications (including dairy, fish, meat, beverages and vinegar) and features a reviewed taxonomy of microorganisms. | 1 | Applied and Interdisciplinary Chemistry |
The theory can be applied also to dilute solutions of mixed electrolytes. Freezing point depression measurements has been used to this purpose. | 0 | Theoretical and Fundamental Chemistry |
The replacement of silica involves two processes:
1) Dissolution of rock minerals
2) Precipitation of silica
It could be explained through the carbonate-silica replacement. Hydrothermal fluids are undersaturated with carbonates and supersaturated with silica. When carbonate rocks get in contact with hydrothermal fluids, due to the difference in gradient, carbonates from the original rock dissolve into the fluid whereas silica precipitate out of it. The carbonate that dissolved is therefore pulled out from the system while the silica precipitated recrystallizes into various silicate minerals, depending on the silica phase. The solubility of silica strongly depends on the temperature and pH value of the environment where pH9 is the controlling value. Under a condition of pH lower than 9, silica precipitates out of the fluid; when the pH value is above 9, silica becomes highly soluble. | 0 | Theoretical and Fundamental Chemistry |
* Water disinfection/decontamination, a form of solar water disinfection (SODIS). Adsorbents attract organics such as tetrachloroethylene. Adsorbents are placed in packed beds for 18 hours. Spent adsorbents are placed in regeneration fluid, essentially removing organics still attached by passing hot water opposite to the flow of water during adsorption. The regeneration fluid passes through fixed beds of silica gel photocatalysts to remove and decompose remaining organics.
* self-sterilizing coatings (for application to food contact surfaces and in other environments where microbial pathogens spread by indirect contact).
*Magnetic nanoparticle oxidation of organic contaminants agitated using a magnetic field.
*Sterilization of surgical instruments and removal of fingerprints from electrical and optical components. | 0 | Theoretical and Fundamental Chemistry |
Glare caused from surfaces with high solar reflectance may present visibility concerns that can limit PDRC application, particularly within urban environments at the ground level. PDRCs that use a "scattering system" to generate reflection in a more diffused manner have been developed and are "more favorable in real applications," as per Lin et al.
Low-cost PDRC colored paint coatings, which reduce glare and increase the color diversity of PDRC surfaces, have also been developed. While some of the surface's solar reflectance is lost in the visible light spectrum, colored PDRCs can still exhibit significant cooling power, such as a coating by Zhai et al., which used a α- coating (resembling the color of the compound) to develop a non-toxic paint that demonstrated a solar reflectance of 99% and heat emissivity of 97%.
Generally it is noted that there is a tradeoff between cooling potential and darker colored surfaces. Less reflective colored PDRCs can also be applied to walls while more reflective white PDRCs can be applied to roofs to increase visual diversity of vertical surfaces, yet still contribute to cooling. | 0 | Theoretical and Fundamental Chemistry |
Sintering is a common practice used widely with both metals and ceramic materials. Sintering is a direct application of capillary condensation, because of the adhesion effects of dust and powders. This application can be seen directly in sol-gel thin film synthesis. The sol-gel is a colloid solution which is placed on a substrate, usually through a dip-coating method. After being placed onto the substrate, a source of heat is applied to evaporate all undesired liquid. While the liquid is evaporating, the particles that were once in solution adhere to each other, thus forming a thin film. | 1 | Applied and Interdisciplinary Chemistry |
Some metabolic myopathies involve the under- or over-utilization of the purine nucleotide cycle. Metabolic myopathies cause a low ATP reservoir in muscle cells (ADP > ATP), resulting in exercise-induced excessive AMP buildup in muscle, and subsequent exercise-induced hyperuricemia (myogenic hyperuricemia) through conversion of excessive AMP into uric acid by way of either AMP → adenosine or AMP → IMP.
During strenuous exercise, AMP is created through the use of the adenylate kinase (myokinase) reaction after the phosphagen system has been depleted of creatine phosphate and not enough ATP is being produced yet by other pathways (see above reaction in Occurrence section). In those affected by metabolic myopathies, exercise that normally wouldn't be considered strenuous for healthy people, is however strenuous for them due to their low ATP reservoir in muscle cells. This results in regular use of the myokinase reaction for normal, everyday activities.
Besides the myokinase reaction, a high ATP consumption and low ATP reservoir also increases protein catabolism and salvage of IMP, which results in increased AMP and IMP. These two nucleotides can then enter the purine nucleotide cycle to produce fumarate which will then produce ATP by oxidative phosphorylation. If the purine nucleotide cycle is blocked (such as AMP deaminase deficiency) or if exercise is stopped and increased fumarate production is no longer needed, then the excess nucleotides will be converted into uric acid. | 1 | Applied and Interdisciplinary Chemistry |
Expression vectors produce proteins through the transcription of the vector's insert followed by translation of the mRNA produced, they therefore require more components than the simpler transcription-only vectors. Expression in different host organism would require different elements, although they share similar requirements, for example a promoter for initiation of transcription, a ribosomal binding site for translation initiation, and termination signals. | 1 | Applied and Interdisciplinary Chemistry |
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