text stringlengths 105 4.57k | label int64 0 1 | label_text stringclasses 2
values |
|---|---|---|
Chlorophyll-a concentration is sometimes used to measure water clarity, especially when suspended sediments and colored dissolved organic matter concentrations are low. Chlorophyll-a concentration is a proxy for phytoplankton biomass, which is one way to quantify how turbid the water is due to biological primary production. Chlorophyll-a concentration is most useful for research on primary production, the contribution of phytoplankton to light attenuation, and harmful algal blooms. Chlorophyll-a concentration is also useful for long-term monitoring because these sensors are often low cost and sturdy enough for long deployments underwater. | 0 | Theoretical and Fundamental Chemistry |
Once excited, atoms will lose their energy fairly quickly. Of the various ways that this energy can be lost, the most important is radiatively, meaning that a photon is released to carry the energy away. In optical atomic spectroscopy, the wavelength of this photon can be used to determine the identity of the atom (that is, which chemical element it is) and the number of photons is directly proportional to the concentration of that element in the sample. Some collisions (those of high enough energy) will cause ionization. In atomic mass spectrometry, these ions are detected. Their mass identifies the type of atoms and their quantity reveals the amount of that element in the sample. | 0 | Theoretical and Fundamental Chemistry |
Ro05-4082 (N-methylclonazepam, ID-690) is a benzodiazepine derivative developed in the 1970s. It has sedative and hypnotic properties, and has around the same potency as clonazepam itself. It was never introduced into clinical use. It is a structural isomer of meclonazepam (3-methylclonazepam), and similarly has been sold as a designer drug, first being identified in Sweden in 2017. | 1 | Applied and Interdisciplinary Chemistry |
Desensitization of the postsynaptic receptors is a decrease in response to the same neurotransmitter stimulus. It means that the strength of a synapse may in effect diminish as a train of action potentials arrive in rapid succession – a phenomenon that gives rise to the so-called frequency dependence of synapses. The nervous system exploits this property for computational purposes, and can tune its synapses through such means as phosphorylation of the proteins involved. | 1 | Applied and Interdisciplinary Chemistry |
The aerodynamic diameter of an irregular particle is defined as the diameter of the spherical particle with a density of 1000 kg/m and the same settling velocity as the irregular particle.
Neglecting the slip correction, the particle settles at the terminal velocity proportional to the square of the aerodynamic diameter, d:
where
: = standard particle density (1000 kg/m).
This equation gives the aerodynamic diameter:
One can apply the aerodynamic diameter to particulate pollutants or to inhaled drugs to predict where in the respiratory tract such particles deposit. Pharmaceutical companies typically use aerodynamic diameter, not geometric diameter, to characterize particles in inhalable drugs. | 0 | Theoretical and Fundamental Chemistry |
Domestic combustion pollution is mainly composed of burning fuel including wood, gas, and charcoal in activities of heating, cooking, agriculture, and wildfires. Major domestic pollutants contain 17% of carbon dioxide, 13% of carbon monoxide, 6% of nitrogen monoxide, polycyclic aromatic hydrocarbons, and fine and ultrafine particles.
In the United Kingdom domestic combustion is the largest single source of PM2.5 annually. In some towns and cities in New South Wales wood smoke may be responsible for 60% of fine particle air pollution in the winter. Research conducted about biomass burning in 2015, estimated that 38% of European total particulate pollution emissions are composed of domestic wood burning.
The particulate pollutant is often in microscopic size that enables it to infiltrate into interior space even if windows and doors are closed. The main component of woodsmoke, black carbon significantly appears in the indoor environment compared to other ambient pollutants. If the room is sealed tight enough to prevent woodsmoke transmission, it will also prevent oxygen exchange from indoors to outdoor. The regular dusk mask also can help little with particulate pollutants since they are designed to filter out larger particles. Musk with HEPA filter can filter out microscopic pollutants but cause difficulty of breathing to the population with lung disease.
Living under high concentrations of pollutants can lead to headaches, fatigue, lung disease, asthma, and throat and eye irritation. One of the most common diseases among those living among pollutants is chronic obstructive pulmonary disease (COPD). Exposure to wood and charcoal smoke is significantly associated with COPD diagnoses among those living in developing and developed countries. Exposure to woodsmoke intensifies the respiratory systems and increases the risk of hospital admissions. | 1 | Applied and Interdisciplinary Chemistry |
Retinal is a chromophore that forms photosensitive Retinylidene proteins when covalently bound to proteins called opsins. Retinal can be photoisomerized by itself, but requires to be bound to an opsin protein to both trigger the phototransduction cascade and tune the spectral sensitivity to longer wavelengths, which enable color vision.
Retinal is a species of retinoid and the aldehyde form of Vitamin A. Retinal is interconvertible with retinol, the transport and storage form of vitamin A. During the visual cycle, retinal moves between several different isomers and is also converted to retinol and retinyl ester. Retinoids can be derived from the oxidation of carotenoids like beta carotene or can be consumed directly. To reach the retina, it is bound to Retinol Binding Protein (RBP) and Transthyretin, which prevents its filtration in the glomeruli.
As in transport via the RBP-Transthyretin pathway, retinoids must always be bound to Chaperone molecules, for several reasons. Retinoids are toxic, insoluble in aqueous solutions, and prone to oxidation, and as such they must be bound and protected when within the body. The body uses a variety of chaperones, particularly in the retina, to transport retinoids. | 1 | Applied and Interdisciplinary Chemistry |
Schwab was born in 1899 in Berlin as the second son of famed journalist and his wife, the writer Marie Köglmayr. Both his parents originated from Bavaria; Josef Schwab was a Franconian Jew and his wife a Catholic from Upper Bavaria. Georg-Maria finished his secondary education at the Friedrich Wilhelm Gymnasium in Berlin, and upon turning 18 was conscripted for WWI and served for a year with the Bavarian Army in Flanders.
Following WWI, Schwab studied Chemistry and Physics in the University of Berlin. He continued his postgraduate studies there under the supervision of Ernst Hermann Riesenfeld and in 1923 received his doctorate with his thesis "Über Ozon" (On Ozone), which was awarded the rare distinction eximium opus. For the following two years, until 1925, Schwab worked as a research assistant to Max Bodenstein, the successor of Walther Nernst in the Institute of Physical Chemistry that Nernst founded in Berlin. Under Bodenstein, Schwab was initiated and trained in the field of chemical kinetics, in which he contributed much for the rest of his career.
In 1925, he accepted a position in the University of Würzburg, initially as the assistant of Otto Dimroth. He was eventually habilitated in 1927 as a Privatdozent in Würzburg with his habilitation thesis on the thermal decomposition of methane and ammonia. In 1928, after the invitation of Heinrich Otto Wieland, Schwab began working in the inorganic laboratory at the University of Munich and was promoted to extraordinary professor in 1933.
It was during this period that he met his future wife Elly Agallidis (), a Greek physicist who was doing her PhD in the University of Munich.
Schwab remained at his position in Munich until 1938, when he was expelled and barred from teaching by Nazi authorities on account of "racial grounds" i.e. his half-Jewish origin. Raised a Catholic, he had been previously unaware of his father's origin until questioned about it under the provisions of the 1933 anti-Semitic Civil Service Law. | 0 | Theoretical and Fundamental Chemistry |
The journal began its publication in 1905 as Transactions of the Faraday Society. When the society merged with the other chemistry societies of the United Kingdom to form the Royal Society of Chemistry, the publication of the journal was transferred to the Chemical Society in 1972 as part of the merger negotiations. The journal was renamed Journal of the Chemical Society, Faraday Transactions, and split in two (Faraday Transactions I: Physical Chemistry in Condensed Phases and Faraday Transactions II: Molecular and Chemical Physics). After the merger, the Royal Society carried the publication until its end. In 1990, the two journals merged into a single Journal of the Chemical Society, Faraday Transactions, which continued publication until 1998 when it merged with a number of other physical chemistry journals published by different societies to form Physical Chemistry Chemical Physics. | 0 | Theoretical and Fundamental Chemistry |
A possible solution for PFAS-contaminated wastewater treatment has been developed by the Michigan State University-Fraunhofer team. Boron-doped diamond electrodes are used for the electrochemical oxidation system where it is capable of breaking PFAS molecular bonds which essentially eliminates the contaminates, leaving fresh water. Cory Rusinek, an electrochemist at MSU-Fraunhofer stated:
Acidimicrobium sp. strain A6 has been shown to be a PFAS and PFOS remediator. PFAS with unsaturated bonds are easier to break down: the commercial dechlorination culture KB1 (contains Dehalococcoides) is capable of breaking down such substances, but not saturated PFAS. When alternative, easier-to-digest substrates are present, microbes may prefer them over PFAS. | 0 | Theoretical and Fundamental Chemistry |
A recurring sub-theme of cloning fiction is the use of clones as a supply of organs for transplantation. The 2005 Kazuo Ishiguro novel Never Let Me Go and the 2010 film adaption are set in an alternate history in which cloned humans are created for the sole purpose of providing organ donations to naturally born humans, despite the fact that they are fully sentient and self-aware. The 2005 film The Island revolves around a similar plot, with the exception that the clones are unaware of the reason for their existence.
The exploitation of human clones for dangerous and undesirable work was examined in the 2009 British science fiction film Moon. In the futuristic novel Cloud Atlas and subsequent film, one of the story lines focuses on a genetically engineered fabricant clone named Sonmi~451, one of millions raised in an artificial "wombtank", destined to serve from birth. She is one of thousands created for manual and emotional labor; Sonmi herself works as a server in a restaurant. She later discovers that the sole source of food for clones, called Soap, is manufactured from the clones themselves.
In the film Us, at some point prior to the 1980s, the US Government creates clones of every citizen of the United States with the intention of using them to control their original counterparts, akin to voodoo dolls. This fails, as they were able to copy bodies, but unable to copy the souls of those they cloned. The project is abandoned and the clones are trapped exactly mirroring their above-ground counterparts' actions for generations. In the present day, the clones launch a surprise attack and manage to complete a mass-genocide of their unaware counterparts. | 1 | Applied and Interdisciplinary Chemistry |
Consider a collection of N non-interacting particles, which can each be in one of two quantum states, and . If the two states are equal in energy, each different configuration is equally likely.
If we can tell which particle is which, there are different configurations, since each particle can be in or independently. In almost all of the configurations, about half the particles are in and the other half in . The balance is a statistical effect: the number of configurations is largest when the particles are divided equally.
If the particles are indistinguishable, however, there are only N+1 different configurations. If there are K particles in state , there are particles in state . Whether any particular particle is in state or in state cannot be determined, so each value of K determines a unique quantum state for the whole system.
Suppose now that the energy of state is slightly greater than the energy of state by an amount E. At temperature T, a particle will have a lesser probability to be in state by . In the distinguishable case, the particle distribution will be biased slightly towards state . But in the indistinguishable case, since there is no statistical pressure toward equal numbers, the most-likely outcome is that most of the particles will collapse into state .
In the distinguishable case, for large N, the fraction in state can be computed. It is the same as flipping a coin with probability proportional to p = exp(−E/T) to land tails.
In the indistinguishable case, each value of K is a single state, which has its own separate Boltzmann probability. So the probability distribution is exponential:
For large N, the normalization constant C is . The expected total number of particles not in the lowest energy state, in the limit that , is equal to
It does not grow when N is large; it just approaches a constant. This will be a negligible fraction of the total number of particles. So a collection of enough Bose particles in thermal equilibrium will mostly be in the ground state, with only a few in any excited state, no matter how small the energy difference.
Consider now a gas of particles, which can be in different momentum states labeled . If the number of particles is less than the number of thermally accessible states, for high temperatures and low densities, the particles will all be in different states. In this limit, the gas is classical. As the density increases or the temperature decreases, the number of accessible states per particle becomes smaller, and at some point, more particles will be forced into a single state than the maximum allowed for that state by statistical weighting. From this point on, any extra particle added will go into the ground state.
To calculate the transition temperature at any density, integrate, over all momentum states, the expression for maximum number of excited particles, :
When the integral (also known as Bose–Einstein integral) is evaluated with factors of and ℏ restored by dimensional analysis, it gives the critical temperature formula of the preceding section. Therefore, this integral defines the critical temperature and particle number corresponding to the conditions of negligible chemical potential . In Bose–Einstein statistics distribution, is actually still nonzero for BECs; however, is less than the ground state energy. Except when specifically talking about the ground state, can be approximated for most energy or momentum states as . | 0 | Theoretical and Fundamental Chemistry |
Syntroleum, a publicly traded United States company, has produced over of diesel and jet fuel from the Fischer–Tropsch process using natural gas and coal at its demonstration plant near Tulsa, Oklahoma. Syntroleum is working to commercialize its licensed Fischer–Tropsch technology via coal-to-liquid plants in the United States, China, and Germany, as well as gas-to-liquid plants internationally. Using natural gas as a feedstock, the ultra-clean, low sulfur fuel has been tested extensively by the United States Department of Energy and the United States Department of Transportation. Syntroleum has worked to develop a synthetic jet fuel blend that will help the Air Force to reduce its dependence on imported petroleum. The Air Force, which is the United States militarys largest user of fuel, began exploring alternative fuel sources in 1999. On December 15, 2006, a B-52 took off from Edwards Air Force Base, California for the first time powered solely by a 50–50 blend of JP-8 and Syntroleums FT fuel. The seven-hour flight test was considered a success. The goal of the flight test program is to qualify the fuel blend for fleet use on the service's B-52s, and then flight test and qualification on other aircraft. The test program concluded in 2007. This program is part of the Department of Defense Assured Fuel Initiative, an effort to develop secure domestic sources for the military energy needs. The Pentagon hopes to reduce its use of crude oil from foreign producers and obtain about half of its aviation fuel from alternative sources by 2016. | 0 | Theoretical and Fundamental Chemistry |
In a classical picture, nuclei can be understood as hard spheres that repel each other through the Coulomb force but fuse once the two spheres come close enough for contact. Estimating the radius of an atomic nuclei as about one femtometer, the energy needed for fusion of two hydrogen is:
This would imply that for the core of the sun, which has a Boltzmann distribution with a temperature of around 1.4 keV, the probability hydrogen would reach the threshold is , that is, fusion would never occur. However, fusion in the sun does occur due to quantum mechanics. | 0 | Theoretical and Fundamental Chemistry |
MER41.AIM2 is an HERV that regulates the transcription of AIM2 (Absent in Melanoma 2) which encodes for a sensor of foreign cytosolic DNA. This acts as a binding site for AIM2, meaning that it is necessary for the transcription of AIM2. Researchers had shown this by deleting MER41.AIM2 in HeLa cells using CRISPR/Cas9, leading to an undetectable transcript level of AIM2 in modified HeLa cells. The control cells, which still contained the MER41.AIM2 ERV, were observed with normal amounts of AIM2 transcript. In terms of immunity, researchers concluded that MER41.AIM2 is necessary for an inflammatory response to infection. | 1 | Applied and Interdisciplinary Chemistry |
Monocytes, activated dendritic cells (DC) and macrophages stimulate the accumulation of IL-23 after exposure to molecules of Gram-positive/negative bacteria or viruses. Receptor for IL-23 contains IL12β and IL23R subunits, which upon binding of IL-23 promotes the phosphorylation STAT4. The presence of IL12β enables similar, although weaker downstream activity as compared to IL-12. During chronic inflammation, IL-23/STAT4 signalling pathway is involved in the induction of differentiation and expansion of Th17 pro-inflammatory T helper cells.
Additionally, other cytokines like IL2, IL 27, IL35, IL18 and IL21 are known to activate STAT4. | 1 | Applied and Interdisciplinary Chemistry |
Second sound is observed in liquid helium at temperatures below the lambda point, 2.1768 K, where He becomes a superfluid known as helium II. Helium II has the highest thermal conductivity of any known material (several hundred times higher than copper). Second sound can be observed either as pulses or in a resonant cavity.
The speed of second sound is close to zero near the lambda point, increasing to approximately 20 m/s around 1.8 K, about ten times slower than normal sound waves.
At temperatures below 1 K, the speed of second sound in helium II increases as the temperature decreases.
Second sound is also observed in superfluid helium-3 below its lambda point 2.5 mK.
As per the two-fluid, the speed of second sound is given by
where is the temperature, is the entropy, is the specific heat, is the superfluid density and is the normal fluid density. As , , where is the ordinary (or first) sound speed. | 0 | Theoretical and Fundamental Chemistry |
Copper tubes have been used to distribute potable water within building for many years and hundreds of miles are installed throughout Europe every year. The long life of copper when exposed to natural waters is a result of its thermodynamic stability, its high resistance to reacting with the environment, and the formation of insoluble corrosion products that insulate the metal from the environment. The corrosion rate of copper in most potable waters is less than 2.5 µm/year, at this rate a 15 mm tube with a wall thickness of 0.7 mm would last for about 280 years. In some soft waters the general corrosion rate may increase to 12.5 µm/year, but even at this rate it would take over 50 years to perforate the same tube. Despite the reliability of copper and copper alloys, in some cold hard waters pits may form in the bore of a tube. If these pits form, failure times can be expected between 6 months and 2 years from initiation. The mechanism that leads to the pitting of copper in cold hard waters is complex, it requires a water with a specific chemistry that is capable of supporting pit growth and a mechanism for the initiation of the pits. | 1 | Applied and Interdisciplinary Chemistry |
This method is designed to be robust where the other methods don't even provide any results in particular. As such, it is indispensable, since it is the only way to use the sessile drop technique on very high surface energy solids. Its major drawback is the fact that it is far more complex, both in its mathematics and experimentally. The Schultz theory requires one to account for many more factors, as there is now the unusual interaction of the probe liquid phase with the surrounding liquid. | 0 | Theoretical and Fundamental Chemistry |
Cadmium sulfide can be prepared by the precipitation from soluble cadmium(II) salts with sulfide ion. This reaction has been used for gravimetric analysis and qualitative inorganic analysis.<br />The preparative route and the subsequent treatment of the product, affects the polymorphic form that is produced (i.e., cubic vs hexagonal). It has been asserted that chemical precipitation methods result in the cubic zincblende form.
Pigment production usually involves the precipitation of CdS, the washing of the solid precipitate to remove soluble cadmium salts followed by calcination (roasting) to convert it to the hexagonal form followed by milling to produce a powder. When cadmium sulfide selenides are required the CdSe is co-precipitated with CdS and the cadmium sulfoselenide is created during the calcination step.
Cadmium sulfide is sometimes associated with sulfate reducing bacteria. | 0 | Theoretical and Fundamental Chemistry |
Carbonatation is a slow process that occurs in concrete where lime (CaO, or Ca(OH)) in the cement reacts with carbon dioxide (CO) from the air and forms calcium carbonate.
The water in the pores of Portland cement concrete is normally alkaline with a pH in the range of 12.5 to 13.5. This highly alkaline environment is one in which the steel rebar is passivated and is protected from corrosion. According to the Pourbaix diagram for iron, the metal is passive when the pH is above 9.5.
The carbon dioxide in the air reacts with the alkali in the cement and makes the pore water more acidic, thus lowering the pH. Carbon dioxide will start to carbonatate the cement in the concrete from the moment the object is made. This carbonatation process will start at the surface, then slowly moves deeper and deeper into the concrete. The rate of carbonatation is dependent on the relative humidity of the concrete - a 50% relative humidity being optimal. If the object is cracked, the carbon dioxide in the air will be better able to penetrate into the concrete.
Eventually this may lead to corrosion of the rebar and structural damage or failure. | 0 | Theoretical and Fundamental Chemistry |
Several modifications of alkynylation reactions are known:
* In the Arens–van Dorp synthesis the compound ethoxyacetylene is converted to a Grignard reagent and reacted with a ketone, the reaction product is a propargyl alcohol.
* The Isler modification is a modification of Arens–Van Dorp Synthesis where ethoxyacetylene is replaced by β-chlorovinyl ethyl ether and lithium amide. | 0 | Theoretical and Fundamental Chemistry |
The theme of traveling through, hiding, or even residing in combined sewers is a common plot device in media. Famous examples of sewer dwelling are the Teenage Mutant Ninja Turtles, Stephen Kings It, Les Misérables, The Third Man, Ladyhawke, Mimic, The Phantom of the Opera, Beauty and the Beast, and Jet Set Radio Future. The Todd Strasser novel Y2K-9: the Dog Who Saved the World' is centered on a dog thwarting terroristic threats to electronically sabotage American sewage treatment plants. | 1 | Applied and Interdisciplinary Chemistry |
Ion channels are also classified according to their subcellular localization. The plasma membrane accounts for around 2% of the total membrane in the cell, whereas intracellular organelles contain 98% of the cell's membrane. The major intracellular compartments are endoplasmic reticulum, Golgi apparatus, and mitochondria. On the basis of localization, ion channels are classified as:
* Plasma membrane channels
**Examples: Voltage-gated potassium channels (Kv), Sodium channels (Nav), Calcium channels (Cav) and Chloride channels (ClC)
* Intracellular channels, which are further classified into different organelles
**Endoplasmic reticulum channels: RyR, SERCA, ORAi
**Mitochondrial channels: mPTP, KATP, BK, IK, CLIC5, Kv7.4 at the inner membrane and VDAC and CLIC4 as outer membrane channels. | 1 | Applied and Interdisciplinary Chemistry |
The sea surface microlayer (SML) is the boundary interface between the atmosphere and ocean, covering about 70% of Earth's surface. With an operationally defined thickness between 1 and , the SML has physicochemical and biological properties that are measurably distinct from underlying waters. Recent studies now indicate that the SML covers the ocean to a significant extent, and evidence shows that it is an aggregate-enriched biofilm environment with distinct microbial communities. Because of its unique position at the air-sea interface, the SML is central to a range of global marine biogeochemical and climate-related processes.
The sea surface microlayer is the boundary layer where all exchange occurs between the atmosphere and the ocean. The chemical, physical, and biological properties of the SML differ greatly from the sub-surface water just a few centimeters beneath.
Despite the huge extent of the ocean's surface, until now relatively little attention has been paid to the sea surface microlayer (SML) as the ultimate interface where heat, momentum and mass exchange between the ocean and the atmosphere takes place. Via the SML, large-scale environmental changes in the ocean such as warming, acidification, deoxygenation, and eutrophication potentially influence cloud formation, precipitation, and the global radiation balance. Due to the deep connectivity between biological, chemical, and physical processes, studies of the SML may reveal multiple sensitivities to global and regional changes.
Understanding the processes at the ocean's surface, in particular involving the SML as an important and determinant interface, could provide an essential contribution to the reduction of uncertainties regarding ocean-climate feedbacks. As of 2017, processes occurring within the SML, as well as the associated rates of material exchange through the SML, remained poorly understood and were rarely represented in marine and atmospheric numerical models. | 0 | Theoretical and Fundamental Chemistry |
AMGs may influence gene expression by modulating the activity of transcription factors, which control the rate at which specific genes are transcribed into mRNA, thereby impacting the levels of corresponding proteins involved in metabolic pathways. | 1 | Applied and Interdisciplinary Chemistry |
Consider two energy eigenstates of a quantum system with Hamiltonian (for example, this could be the Hamiltonian of a particle in a potential, like the Hydrogen atom or the Alkali atoms):
We want to consider the time dependent Hamiltonian
where is the potential of the electromagnetic field. Treating the potential as a perturbation, we can expect the eigenstates of the perturbed Hamiltonian to be some mixture of the eigenstates of the original Hamiltonian with time dependent coefficients:
Plugging this into the time dependent Schrödinger equation
taking the inner product with each of and , and using the orthogonality condition of eigenstates , we arrive at two equations in the coefficients and :
where . The two terms in parentheses are dipole matrix elements dotted into the polarization vector of the electromagnetic field. In considering the spherically symmetric spatial eigenfunctions of the Hydrogen atom potential, the diagonal matrix elements go to zero, leaving us with
or
Here , where is the Rabi Frequency. | 0 | Theoretical and Fundamental Chemistry |
Historic instruments are the first backscattering spectrometer that was a temporary setup at FRM I
and the backscattering spectrometer BSS (also called PI) at the DIDO reactor of the Forschungszentrum Jülich (decommissioned). | 0 | Theoretical and Fundamental Chemistry |
The electrochemical window (EW) is an important concept in organic electrosynthesis and design of batteries, especially organic batteries. This is because at higher voltage (greater than 4.0 V) organic electrolytes decompose and interferes with the oxidation and reduction of the organic cathode/anode materials. For this reason, the best organic electrolytes should be characterized by a wider range of electrochemical window, i.e., greater than the working range of the battery cell voltage. For example, the electrochemical window of Lithium bis- (trifluoromethanesulfonyl)imide, commercially known as LiTFSI is about 3.0 V because it can operate in the range of 1.9 -4.9 V. On the other hand, for electrolytes that are characterized by narrow electrochemical window, they are prone to irreversible decomposition, which in turn triggers the battery capacity decaying during subsequent battery cycling.
The electrochemical window of organic electrolyte depends on many factors that include temperature, molecular frontier orbitals such LUMO (Lowest Unoccupied Molecular Orbital) and HOMO (Highest occupied Molecular Orbital) because the mechanisms of reduction (electron gaining) and oxidation (electron loss) are governed by band gap between HOMO and LUMO. Solvation energy also plays an important role in defining the electrochemical window of the electrolyte.
In order to safeguard the thermodynamic stability working conditions of the electrode materials in a given electrolyte, the electrochemical potentials of the electrode materials (anode and cathode) must be comprised within the electrochemical stability of the electrolyte. This condition is very succinct because electrolyte might be oxidized when the cathode material possess an electrochemical potential, which is less than the electrolyte oxidation potential. When the electrochemical potential of the anode material is quite higher than the reduction potential of the electrolyte, the electrolyte will be degraded through reduction process. | 0 | Theoretical and Fundamental Chemistry |
A 3D COF was created, characterised by an interconnected mesoporous scaffold that showed effective drug loading and release in a simulated body fluid environment, making it useful as a nanocarrier for pharmaceutical drugs. | 0 | Theoretical and Fundamental Chemistry |
In Marfan syndrome, a connective tissue disorder, mutations in the gene encoding for the fibrillin-1 protein impact nearly every one of its domains. Such defects in fibrillin-1 affect the signaling of TGFβ, as microfibrils directly govern the activity of TGFβ. This hinders the formation of the extracellular matrix, and ultimately results in a severe phenotype which involves a few organ systems, including the central nervous system, circulatory system, ocular system, and skeletal system. | 1 | Applied and Interdisciplinary Chemistry |
Founded in 1974, the International Atomic Energy Agency (IAEA) was created to set forth international standards for nuclear reactor safety. However, without a proper policing force, the guidelines set forth by the IAEA were often treated lightly or ignored completely. In 1986, the disaster at Chernobyl was evidence that international nuclear reactor safety was not to be taken lightly. Even in the midst of the Cold War, the Nuclear Regulatory Commission sought to improve the safety of Soviet nuclear reactors. As noted by IAEA Director General Hans Blix, "A radiation cloud doesn't know international boundaries." The NRC showed the Soviets the safety guidelines used in the US: capable regulation, safety-minded operations, and effective plant designs. The Soviets, however, had their own priority: keeping the plant running at all costs. In the end, the same shift between deterministic safety designs to probabilistic safety designs prevailed. In 1989, the World Association of Nuclear Operators (WANO) was formed to cooperate with the IAEA to ensure the same three pillars of reactor safety across international borders. In 1991, WANO concluded (using a probabilistic safety approach) that all former communist-controlled nuclear reactors could not be trusted, and should be closed. Compared to a "Nuclear Marshall Plan", efforts were taken throughout the 1990s and 2000s to ensure international standards of safety for all nuclear reactors. | 0 | Theoretical and Fundamental Chemistry |
Ring A (12) and ring C (19) reacted together to alcohol 20 in a Shapiro reaction (tBuLi, CeCl) in a similar way as in the Nicolaou Taxol total synthesis. Subsequent steps were epoxidation (VO(acac), tBuOH) to 21, reduction (LiAlH) to the diol and alcohol protection (aqueous KOH, BnBr, BuNHSO) to benzyl ether 22, alcohol protection (MeSiHCl, imidazole) and oxidation (DDQ) to DMS ether 23, tosylation (TsCl, DMAP) to 24, deprotection to diol (TBAF) and reprotection (TMSOTf, 2,6-lutidine, DIPEA) as TMS ether 25, Ley oxidation to aldehyde 26, cyanohydrin formation (TMSCN, 18-crown-6, KCN) and alcohol protection (ethyl vinyl ether, camphorsulfonic acid) to EE ether 27. | 0 | Theoretical and Fundamental Chemistry |
Water saturation is the fraction of porevolume that is filled with water, and similar for oil saturation . Thus, saturations are in itselves scaled properties or variables. This gives the constraint
The model functions or correlations for relative permeabilities in an oil-water system are therefore usually written as functions of only water saturation, and this makes it natural to select water saturation as the horizontal axis in graphical presentations. Let (also denoted and sometimes ) be the irreducible (or minimal or connate) water saturation, and let be the residual (minimal) oil saturation after water flooding (imbibition). The flowing water saturation window in a water invasion / injection / imbibition process is bounded by a minimum value and a maximum value . In mathematical terms the flowing saturation window is written as
By scaling the water saturation to the flowing saturation window, we get a (new or another) normalized water saturation value
and a normalized oil saturation value | 1 | Applied and Interdisciplinary Chemistry |
It is often noted that beer served by gravity (that is, directly from a tap in the cask) is less heavily carbonated than the same beer served via a hand-pump (or beer-engine). This is because beer is pressured on its way to the point of service by the action of the beer engine, which causes carbon dioxide to dissolve in the beer. This then comes out of solution once the beer has left the pump, causing a higher level of perceptible condition in the beer. | 0 | Theoretical and Fundamental Chemistry |
The first generation carcerands are based on calixarene hemicarcerands with 4 alkyl substituents on the upper rim and 4 reactive substituents on the lower rim. The coupling of both hemicarcerands takes place through a spacer group. In the original 1985 publication two different hemicarcerands react, one with chloromethylene reactive groups and one with thiomethylene reactive groups in a nucleophilic displacement and the resulting spacer group is a dimethylsulfide (CHSCH). In this experiment the guests were the molecules already present in the reaction medium such as argon and dimethylformamide.
In another configuration the 4 lower rim functional groups are aldehydes which condense with O-Phenylenediamine to the corresponding di-imines. The 4 spacer groups connecting the two spheres are now much longer and consequently the internal cavity is much larger. Compounds trapped in the cavity are said to be held there by constrictive binding. They can be introduced by simply heating in neat solvent like hexachlorobutadiene (a fungicide). The half-life of the reverse process is 3.2 hours at 25 °C in CDCl by NMR analysis. Ferrocene can be introduced by heating with the hemicarcerand in a large bulky solvent such as tripiperidylphosphine oxide. The half-life for ferrocene liberation is 19.6 hours at 112 °C. | 0 | Theoretical and Fundamental Chemistry |
For cast iron the equivalent carbon content (CE) concept is used to understand how alloying elements will affect the heat treatment and casting behavior. It is used as a predictor of strength in cast irons because it gives an approximate balance of austenite and graphite in final structure. A number of formulas are available to determine the CE in cast irons, where an increasing number of elements are included:
This CE is then used to determine if the alloy is hypoeutectic, eutectic, or hypereutectic; for cast irons the eutectic is 4.3% carbon. When casting cast iron this is useful for determining the final grain structure; for example, a hypereutectic cast iron usually has a coarse grain structure and large kish graphite flakes are formed. Also, there is less shrinkage as the CE increases. When heat treating cast iron, various CE samples are tested to empirically determine the correlation between CE and hardness. The following is an example for induction hardened gray irons: | 1 | Applied and Interdisciplinary Chemistry |
Al-Kindi theorized that there was a separate, incorporeal and universal intellect (known as the "First Intellect"). It was the first of Gods creation and the intermediary through which all other things came into creation. Aside from its obvious metaphysical importance, it was also crucial to al-Kindis epistemology, which was influenced by Platonic realism.
According to Plato, everything that exists in the material world corresponds to certain universal forms in the heavenly realm. These forms are really abstract concepts such as a species, quality or relation, which apply to all physical objects and beings. For example, a red apple has the quality of "redness" derived from the appropriate universal. However, al-Kindi says that human intellects are only potentially able to comprehend these. This potential is actualized by the First Intellect, which is perpetually thinking about all of the universals. He argues that the external agency of this intellect is necessary by saying that human beings cannot arrive at a universal concept merely through perception. In other words, an intellect cannot understand the species of a thing simply by examining one or more of its instances. According to him, this will only yield an inferior "sensible form", and not the universal form which we desire. The universal form can only be attained through contemplation and actualization by the First Intellect.
The analogy he provides to explain his theory is that of wood and fire. Wood, he argues, is potentially hot (just as a human is potentially thinking about a universal), and therefore requires something else which is already hot (such as fire) to actualize this. This means that for the human intellect to think about something, the First Intellect must already be thinking about it. Therefore, he says that the First Intellect must always be thinking about everything. Once the human intellect comprehends a universal by this process, it becomes part of the individual's "acquired intellect" and can be thought about whenever he or she wishes. | 1 | Applied and Interdisciplinary Chemistry |
Cefuroxime, sold under the brand name Zinacef among others, is a second-generation cephalosporin antibiotic used to treat and prevent a number of bacterial infections. These include pneumonia, meningitis, otitis media, sepsis, urinary tract infections, and Lyme disease. It is used by mouth or by injection into a vein or muscle.
Common side effects include nausea, diarrhea, allergic reactions, and pain at the site of injection. Serious side effects may include Clostridium difficile infection, anaphylaxis, and Stevens–Johnson syndrome. Use in pregnancy and breastfeeding is believed to be safe. It is a second-generation cephalosporin and works by interfering with a bacteria's ability to make a cell wall resulting in its death.
Cefuroxime was patented in 1971, and approved for medical use in 1977. It is on the World Health Organization's List of Essential Medicines. In 2020, it was the 325th most commonly prescribed medication in the United States, with more than 800thousand prescriptions. | 0 | Theoretical and Fundamental Chemistry |
Ataxia telangiectasia mutated (ATM) is a kinase that (similar to mTOR) can phosphorylate KAP1 resulting in the switch from viral latency to the lytic cycle. Chloroquine (an ATM) activator has been shown to result in increases in transcription of the HCMV genome. This effect is augmented by the use of tumor necrosis factor It has been proposed that this treatment (accompanied by antiretroviral treatment) has the potential to purge the virus from infected individuals. | 1 | Applied and Interdisciplinary Chemistry |
The Fowkes hypothesis (after F. M. Fowkes) is a first order approximation for surface energy. It states the surface energy is the sum of each component's forces:
γ=γ+γ+γ+...
where γ is the dispersion component, γ is the polar, γ is the dipole and so on.
The Fowkes hypothesis goes further making the approximation that the interface between an apolar liquid and apolar solid where there are only dispersive interactions acting across the interface can be estimated using the geometric mean of the contributions from each surface i.e.
γ=γ+γ-2(γ x γ) | 0 | Theoretical and Fundamental Chemistry |
Awards that Ramsey has received include the Ralph N. Adams Award in Bioanalytical Chemistry (2013), the CASSS Award for Outstanding Achievements in Separation Science (2012), the American Chemical Society Award in Chromatography (2007), the Pittsburgh Analytical Chemistry Award (2006), the ACS Division of Analytical Chemistry Award in Chemical Instrumentation (2003), the Battelle Distinguished Inventor Award (2003), and the Frederick Conference Capillary Electrophoresis Award (2000).
Ramsey holds professional memberships with National Academy of Engineering, the American Chemical Society, and the Analytical Division of the American Chemical Society.
He has 108 issues patents, 2 allowed patents, and 20 pending patents. | 0 | Theoretical and Fundamental Chemistry |
The Rushton turbine or Rushton disc turbine is a radial flow impeller used for many mixing applications (commonly for gas dispersion applications) in process engineering and was invented by John Henry Rushton. The design is based on a flat horizontal disk, with flat, vertically-mounted blades. Recent innovations include the use of concave or semi-circular blades. | 1 | Applied and Interdisciplinary Chemistry |
The method analyzes the shallow WGS reads in windows while considering the cfDNA fragment length and coverage. The genome-wide pattern of cfDNA fragmentation features is then fed to a gradient tree-boosting machine learning model to predict their cancer situation. They also used machine learning classifiers to predict the tissue of origin. Overall, the method can be used to identify if a patient has cancer. Even though the method does not specifically classify the cancer types during prediction, it is used for the detection of different cancers. | 1 | Applied and Interdisciplinary Chemistry |
Anti-PM-Scl antibodies are found in up to 50% of polymyositis/systemic sclerosis (PM/SSc) overlap syndrome. Around 80% of individuals with antibodies present in their blood serum will have the disorder. The presence of the antibodies is linked to limited cutaneous involvement of PM/SSc overlap syndrome. The antigenic targets of the antibodies are components of the RNA-processing exosome complex in the nucleolus. There are ten proteins in this complex and antibodies to eight of them are found at varying frequencies; PM/Scl-100 (70–80%), PM/Scl-75 (46–80%), hRrp4 (50%), hRrp42 (21%), hRrp46 (18%), hCs14 (14%), hRrp41 (10%) and hRrp40 (7%). | 1 | Applied and Interdisciplinary Chemistry |
The Michelson spectrograph is similar to the instrument used in the Michelson–Morley experiment. Light from the source is split into two beams by a half-silvered mirror, one is reflected off a fixed mirror and one off a movable mirror, which introduces a time delay—the Fourier-transform spectrometer is just a Michelson interferometer with a movable mirror. The beams interfere, allowing the temporal coherence of the light to be measured at each different time delay setting, effectively converting the time domain into a spatial coordinate. By making measurements of the signal at many discrete positions of the movable mirror, the spectrum can be reconstructed using a Fourier transform of the temporal coherence of the light. Michelson spectrographs are capable of very high spectral resolution observations of very bright sources.
The Michelson or Fourier-transform spectrograph was popular for infra-red applications at a time when infra-red astronomy only had single-pixel detectors. Imaging Michelson spectrometers are a possibility, but in general have been supplanted by imaging Fabry–Pérot instruments, which are easier to construct. | 0 | Theoretical and Fundamental Chemistry |
Ions in 5th analytical group of cations form carbonates that are insoluble in water. The reagent usually used is (NH)CO (at around 0.2 M), with a neutral or slightly basic pH. All the cations in the previous groups are separated beforehand, since many of them also form insoluble carbonates.
The most important ions in the 5th group are Ba, Ca, and Sr. After separation, the easiest way to distinguish between these ions is by testing flame colour: barium gives a yellow-green flame, calcium gives brick red, and strontium, crimson red. | 0 | Theoretical and Fundamental Chemistry |
Transferrin is also associated with the innate immune system. It is found in the mucosa and binds iron, thus creating an environment low in free iron that impedes bacterial survival in a process called iron withholding. The level of transferrin decreases in inflammation. | 1 | Applied and Interdisciplinary Chemistry |
Cellulose sulphate is derived from cotton and, once processed appropriately, can be used as a biocompatible base in which to suspend cells. When the poly-anionic cellulose sulphate solution is immersed in a second, poly-cationic solution (e.g. pDADMAC), a semi-permeable membrane is formed around the suspended cells as a result of gelation between the two poly-ions. Both mammalian cell lines and bacterial cells remain viable and continue to replicate within the capsule membrane in order to fill-out the capsule. As such, in contrast to some other encapsulation materials, the capsules can be used to grow cells and act as such like a mini-bioreactor. The biocompatible nature of the material has been demonstrated by observation during studies using the cell-filled capsules themselves for implantation as well as isolated capsule material. Capsules formed from cellulose sulphate have been successfully used, showing safety and efficacy, in clinical and pre-clinical trials in both humans and animals, primarily as anti-cancer treatments, but also exploring possible uses for gene therapy or antibody therapies. Using cellulose sulphate it has been possible to manufacture encapsulated cells as a pharmaceutical product at large scale and fulfilling Good Manufacturing Process (cGMP) standards. This was achieved by the company [https://austrianova.com/ Austrianova] in 2007. | 1 | Applied and Interdisciplinary Chemistry |
Roy Jensen in 1976 theorised that primordial enzymes had to be highly promiscuous in order for metabolic networks to assemble in a patchwork fashion (hence its name, the patchwork model). This primordial catalytic versatility was later lost in favour of highly catalytic specialised orthologous enzymes. As a consequence, many central-metabolic enzymes have structural homologues that diverged before the last universal common ancestor. | 1 | Applied and Interdisciplinary Chemistry |
In most environmental situations the presence or absence of an organism is determined by a complex web of interactions only some of which will be related to measurable chemical or biological parameters. Flow rate, turbulence, inter and intra specific competition, feeding behaviour, disease, parasitism, commensalism and symbiosis are just a few of the pressures and opportunities facing any organism or population. Most chemical constituents favour some organisms and are less favourable to others. However, there are some cases where a chemical constituent exerts a toxic effect. i.e. where the concentration can kill or severely inhibit the normal functioning of the organism. Where a toxic effect has been demonstrated this may be noted in the sections below dealing with the individual parameters. | 1 | Applied and Interdisciplinary Chemistry |
Trinitroethylorthocarbonate also known as TNEOC is an organic compound with the chemical formula . It is an oxidizer with excellent chemical stability. Its explosion point is 238 °C, and it begins to be decomposed at 200 °C. Its explosion heat is 5.797 J/g and specific volume is 694 L/kg. Its structure is closely related to that of trinitroethylorthoformate (TNEOF). Both are highly explosive and very shock-sensitive, and may be dissolved in nitroalkanes to reduce their shock-sensitivity. | 0 | Theoretical and Fundamental Chemistry |
*Coal and oil are possible examples of constituents which may have undergone changes over geologic time periods.
*Chalk and limestone are examples of secretions (marine animal shells) which are of geologic age.
*grass and wood are biogenic constituents of contemporary origin.
*Pearls, silk and ambergris are examples of secretions of contemporary origin.
*Biogenic neurotransmitters. | 0 | Theoretical and Fundamental Chemistry |
Water normally flows faster around piers and abutments making them susceptible to local scour. At bridge openings, contraction scour can occur when water accelerates as it flows through an opening that is narrower than the channel upstream from the bridge. Degradation scour occurs both upstream and downstream from a bridge over large areas. Over long periods of time, this can result in the lowering of the stream bed. | 1 | Applied and Interdisciplinary Chemistry |
Ideas for green urban structures began in the 1870s with concepts of urban farming and garden allotments. Alternative terminology includes stormwater best management practices, source controls, and low impact development (LID) practices.
Green infrastructure concepts originated in mid-1980s proposals for best management practices that would achieve more holistic stormwater quantity management goals for runoff volume reduction, erosion prevention, and aquifer recharge. In 1987, amendments to the U.S. Clean Water Act introduced new provisions for management of diffuse pollutant sources from urban land uses, establishing the regulatory need for practices that unlike conventional drainage infrastructure managed runoff "at source." The U.S. Environmental Protection Agency (EPA) published its initial regulations for municipal separate storm sewer systems ("MS4") in 1990, requiring large MS4s to develop stormwater pollution prevention plans and implement "source control practices". EPAs 1993 handbook, Urban Runoff Pollution Prevention and Control Planning', identified best management practices to consider in such plans, including vegetative controls, filtration practices and infiltration practices (trenches, porous pavement). Regulations covering smaller municipalities were published in 1999. MS4s serve over 80% of the US population and provide drainage for 4% of the land area.
Green infrastructure is a concept that highlights the importance of the natural environment in decisions about land-use planning. However, the term does not have a widely recognized definition. Also known as “blue-green infrastructure”, or “green-blue urban grids” the terms are used by many design-, conservation- and planning-related disciplines and commonly feature stormwater management, climate adaptation and multifunctional green space.
The term "green infrastructure" is sometimes expanded to "multifunctional" green infrastructure. Multifunctionality in this context refers to the integration and interaction of different functions or activities on the same piece of land.
The EPA extended the concept of “green infrastructure” to apply to the management of stormwater runoff at the local level through the use of natural systems, or engineered systems that mimic natural systems, to treat polluted runoff. This use of the term "green infrastructure" to refer to urban "green" best management practices contributes to the overall health of natural ecosystems, even though it is not central to the larger concept.
However, it is apparent that the term “blue-green infrastructure” is applied in an urban context and places a greater emphasis on the management of stormwater as an integral part of creating a sustainable, multifunctional urban environment. At the building level, the term "blue-green architecture" is used, which implements the same principles on a smaller scale. The focus here is on building greening with water management from alternative water resources such as grey water and rainwater. | 1 | Applied and Interdisciplinary Chemistry |
Two-dimensional chromatography is a type of chromatographic technique in which the injected sample is separated by passing through two different separation stages. Two different chromatographic columns are connected in sequence, and the effluent from the first system is transferred onto the second column. Typically the second column has a different separation mechanism, so that bands that are poorly resolved from the first column may be completely separated in the second column. (For instance, a C18 reversed-phase chromatography column may be followed by a phenyl column.) Alternately, the two columns might run at different temperatures. During the second stage of separation the rate at which the separation occurs must be faster than the first stage, since there is still only a single detector. The plane surface is amenable to sequential development in two directions using two different solvents. | 0 | Theoretical and Fundamental Chemistry |
Finally, fluids with an even higher molecular complexity can exhibit non-classical behavior in the single-phase vapor region near saturation. They are called Bethe-Zel’dovich-Thompson (BZT) fluids, from the name of physicists Hans Bethe, Yakov Zel'dovich, and Philip Thompson, who first worked on these kinds of fluids.
For thermodynamic conditions lying in the non-classical regime, the non-monotone evolution of the Mach number in isentropic expansions can be found even in subsonic conditions. In fact, for values of , positive values of can be reached also in subsonic flows (). In other words, the non-monotone Mach number evolution is also possible in the convergent section of an isentropic nozzle.
Moreover, a peculiar phenomenon of the non-classical regime is the so-called inverted gas-dynamics. In the classical regime, expansions are smooth isentropic processes, while compressions occur through shock waves, which are discontinuities in the flow. If gas-dynamics is inverted, the opposite occurs, namely rarefaction shock waves are physically admissible and compressions occur through smooth isentropic processes.
As a consequence of the negative value of , two other peculiar phenomena can occur for BZT fluids: shock splitting and composite waves. Shock splitting occurs when an inadmissible pressure discontinuity evolves in time by generating two weaker shock waves. Composite waves, instead, are referred to as phenomena in which two elementary waves propagate as a single entity.
Experimental evidence of a non-classical gas-dynamic regime is not available yet. The main reasons are the complexity of performing experiments in such challenging thermodynamic conditions and the thermal stability of these very complex molecules. | 0 | Theoretical and Fundamental Chemistry |
A baratropic star with and is stable if the quantity
is non-negative for all real functions that conserve the total mass of the star .
where
* is the coordinate system fixed to the center of the star
* is the radius of the star
* is the volume of the star
* is the unperturbed density
* is the small perturbed density such that in the perturbed state, the total density is
* is the self-gravitating potential from Newton's law of gravity
* is the Gravitational constant | 1 | Applied and Interdisciplinary Chemistry |
Methanogens are observed in anoxic soil environments, contributing to the degradation of organic matter. This organic matter may be placed by humans through landfill, buried as sediment on the bottom of lakes or oceans as sediments, and as residual organic matter from sediments that have formed into sedimentary rocks. | 1 | Applied and Interdisciplinary Chemistry |
Otto Neubauer (8 April 1874 – 24 November 1957) was a Bohemia-born physician and biochemist who was responsible for several clinical diagnostic innovations including the Neubauer-Fischer test to evaluate kidney function and the Neubauer counting chamber. | 1 | Applied and Interdisciplinary Chemistry |
Urinary VMA is elevated in patients with tumors that secrete catecholamines.
These urinalysis tests are used to diagnose an adrenal gland tumor called pheochromocytoma, a tumor of catecholamine-secreting chromaffin cells. These tests may also be used to diagnose neuroblastomas, and to monitor treatment of these conditions.
Norepinephrine is metabolised into normetanephrine and VMA. Norepinephrine is one of the hormones produced by the adrenal glands, which are found on top of the kidneys. These hormones are released into the blood during times of physical or emotional stress, which are factors that may skew the results of the test. | 1 | Applied and Interdisciplinary Chemistry |
The National Environmental Engineering Research Institute (NEERI) in Nagpur was originally established in 1958 as the Central Public Health Engineering Research Institute (CPHERI). It has been described as the "premier and oldest institute in India." It is an institution listed on the Integrated Government Online Directory. It operates under the aegis of the Council of Scientific and Industrial Research (CSIR), based in New Delhi. Indira Gandhi, the Prime Minister of India at the time, renamed the Institute NEERI in 1974.
The Institute primarily focused on human health issues related to water supply, sewage disposal, diseases, and industrial pollution.
NEERI operates as a laboratory in the field of environmental science and engineering and is one of the constituent laboratories of the Council of Scientific and Industrial Research (CSIR). The institute has six zonal laboratories located in Chennai, Delhi, Hyderabad, Kolkata,Nagpur, and Mumbai. NEERI operates under the Ministry of Science and Technology of the Indian government. NEERI is a partner organization of India's POPs National Implementation Plan (NIP). | 1 | Applied and Interdisciplinary Chemistry |
Mechanical stimulation to spines on the arm can cause Amphiura filiformis to bioluminesce in the blue range. The species has been found to possess a luciferase compound. The luciferase has been isolated to clusters of photocytes that exist at the tip off the arms and around the spines. What are believed to be photocytes based on evidence have been found around the spine nerve plexus, mucus cells, and what are believed to be pigment cells. It has been found that luminescence is controlled by the animal's nervous system. Acetylcholine is able to stimulate the cells through nicotinic receptors. | 1 | Applied and Interdisciplinary Chemistry |
Rutherford continued to make ground-breaking discoveries long after receiving the Nobel prize in 1908. Along with Hans Geiger and Ernest Marsden in 1909, he carried out the Geiger–Marsden experiment, which demonstrated the nuclear nature of atoms by measuring the deflection of alpha particles passing through a thin gold foil. Rutherford was inspired to ask Geiger and Marsden in this experiment to look for alpha particles with very high deflection angles, which was not expected according to any theory of matter at that time. Such deflection angles, although rare, were found. It was Rutherfords interpretation of this data that led him to formulate the Rutherford model of the atom in 1911that a very small charged nucleus, containing much of the atoms mass, was orbited by low-mass electrons.
In 1912, Rutherford was joined by Niels Bohr (who postulated that electrons moved in specific orbits). Bohr adapted Rutherfords nuclear structure to be consistent with Max Plancks quantum theory, and the resulting Rutherford–Bohr model is considered valid to this day. | 1 | Applied and Interdisciplinary Chemistry |
MIRO Analytical is a spin-off of Empa, a Swiss research institute of the ETH domain. It has know-how in laser spectroscopy and in particular, in the combination of several quantum-cascade lasers (QCLs) into compact laser-based gas analyzers.
The company's first instrument was a nine gas analyzer MGA-9 in 2018. By 2019 the MGA-10 a ten gas analyzer was introduced which measures greenhouse gases and air pollutants. | 0 | Theoretical and Fundamental Chemistry |
Adenosine diphosphate ribose (ADPR) is an ester molecule formed into chains by the enzyme poly ADP ribose polymerase. ADPR is created from cyclic ADP-ribose (cADPR) by the CD38 enzyme using nicotinamide adenine dinucleotide (NAD) as a cofactor.
ADPR binds to and activates the TRPM2 ion channel. ADPR is the most potent agonist of the TRPM2 channel. cADPR also binds to TPRM2, and the action of both molecules is synergistic, with both molecules enhancing the action of the other molecule in activating the TRPM2 channel. Researchers are not sure how the Adenosine diphosphate reacts with the TRPM2 channel, but the ribose sugar may play a role in activating the TRPM2 ion channel. | 1 | Applied and Interdisciplinary Chemistry |
In 1843, Carl Gustaf Mosander discovered terbium and erbium as components of yttria.
However, this discovery was hotly contested. Spectroscopist Nils Johan Berlin denied that the two elements existed, failing to confirm the existence of "erbia" and suggesting that its name be applied to "terbia".
In 1864, Marc Delafontaine used optical spectroscopy to conclusively prove that yttrium, terbium, and erbium were separate elements. Ironically, however, the confusion that had been introduced between the names continued. Mosander's proposed names were switched, giving the amethyst compound the name "erbium" oxide and the yellow substance the name "terbium" oxide, instead of the other way around as originally proposed. | 1 | Applied and Interdisciplinary Chemistry |
Boric acid also dissolves in anhydrous sulfuric acid according to the equation:
The product is an extremely strong acid, even stronger than the original oleum. | 0 | Theoretical and Fundamental Chemistry |
The concept of using reinforced lipids to inhibit lipid peroxidation has been tested in numerous cell and animal
models, including:
* Parkinson's disease (MPTP and a-Syn models in mice and rats)
* Huntington's disease (in mice)
* Alzheimer's disease (APP/PS1 and ALDH2 mouse models)
* Diabetic retinopathy (Akita mice)
* Age-related macular degeneration (light irradiation in rats, eye iron overload in mice)
* Atherosclerosis (Leiden mice) | 1 | Applied and Interdisciplinary Chemistry |
NADH:ubiquinone oxidoreductase complex assembly factor 6 is a protein that in humans is encoded by the NDUFAF6 gene. The protein is involved in the assembly of complex I in the mitochondrial electron transport chain. Mutations in the NDUFAF6 gene have been shown to cause Complex I deficiency, Leigh syndrome, and Acadian variant Fanconi Syndrome. | 1 | Applied and Interdisciplinary Chemistry |
Penile erection is a hemodynamic event in the smooth muscle of corpus cavernous. PDE5 is the main cGMP hydrolysing enzyme found in penile corpus cavernous. Erection is triggered by release of the neurotransmitter nitric oxide (NO) from non-adrenergic and non-cholinergic neurons from nerve ending in the penis as well as from endothelial cells. NO activates soluble guanylyl cyclase in smooth muscle cells in the penis which results in increased production of 3-5-cyclic guanosine monophosphate from guanosine-5'-triphosphate (GTP). Cyclic GMP binds to the cGMP-dependent protein kinase (PKG1) which phosphorylates several proteins that results in decreased intracellular calcium. Lower intracellular calcium leads to smooth muscle relaxation and ultimately penile erection. This pathway is demonstrated in . | 1 | Applied and Interdisciplinary Chemistry |
Iodic acid crystallises from acidic solution as orthorhombic α- in space group P222. The structure consists of pyramidal molecules linked by hydrogen bonding and intermolecular iodine-oxygen interactions. The I=O bond lengths are 1.81 Å while the I–OH distance is 1.89 Å. Several other polymorphs have been reported, including an orthorhombic γ form in space group Pbca and an orthorhombic δ form in space group P222. All of the polymorphs contain pyramidal molecules, hydrogen bonding and I···O interactions, but differ in packing arrangement. | 0 | Theoretical and Fundamental Chemistry |
Macroscopically, the theorem may be useful environmentally, in ecophysics. An ecosystem is a complex system, where many factors and components interact, some biotic and some abiotic. The Gouy-Stodola theorem can find how much entropy is generated by each part of the system, or how much work is lost. Where there is human interference in an ecosystem, whether the ecosystem continues to exist or is lost may depend on how many irreversibilities it can support. The amount of entropy which is generated or the amount of work the system can perform may vary. Hence, two different states (for example, a healthy forest versus one which has undergone significant deforestation) of the same ecosystem may be compared in terms of entropy generation, and this may be used to evaluate the sustainability of the ecosystem under human interference. | 0 | Theoretical and Fundamental Chemistry |
The above equations of state suggest methods to experimentally measure changes in the thermodynamic potentials using physically measurable parameters. For example the free energy expressions
and
can be integrated at constant temperature and quantities to obtain:
can be integrated:
:<math>
\Delta H = \int_{S1}^{S2}T\,\mathrm{d}S = \Delta Q\,\,\,\,
:<math>
\Delta U = \int_{S1}^{S2}T\,\mathrm{d}S = \Delta Q\,\,\,\,
Note that these measurements are made at constant {N } and are therefore not applicable to situations in which chemical reactions take place. | 0 | Theoretical and Fundamental Chemistry |
The Goldsmiths' Professorship of Materials Science is a professorship in the University of Cambridge, associated with the Department of Materials Science and Metallurgy.
The professorship was established by grace of 20 November 1931 as the Goldsmiths Professorship of Metallurgy to replace the Goldsmiths Readership in Metallurgy. A further gift of £12,500 was received from the Goldsmiths Company in 1933. It was retitled the Goldsmiths Professorship of Materials Science by grace 4 of 19 June 1991. | 1 | Applied and Interdisciplinary Chemistry |
In chemistry, a sultine is a cyclic ester of a sulfinic acid. This class of organosulfur compounds has few applications. These compounds are typically prepared by the dehydration of hydroxy-sulfinic acids or their equivalent. Illustrative of an alternative route, xylylene dibromide reacts with sodium sulfoxylate (source of SO) to give the sultine CH(CHS(O)OCH), which is a precursor to o-quinodimethane. | 0 | Theoretical and Fundamental Chemistry |
Murray, David Norris and Manoj Nirmal were the first graduate students to work with Moungi Bawendi at MIT. As part of his thesis work, Murray helped to develop synthetic methods for making quantum dots, including identifying a longer chain version of trioctylphosphine oxide as being cheaper and having additional benefits when used in synthesis. In 1993, Murray, Norris and Bawendi published a breakthrough paper describing the hot injection synthesis method for making quantum dots. Both Murrays and Bawendis contributions to the synthesis and characterization of semiconductor quantum dots were recognized by the American Chemical Society with its 1997 Nobel Laureate Signature Award.
Their method was both adaptable and reproducible, making it possible to consistently synthesise monodisperse nanoparticles and develop large-scale applications using quantum dots. Bawendi received the 2023 Nobel Prize in Physics for the development of this method.
Much of Murray's has work focused on the synthesis and characterization of nanoscale materials, including nanoscale magnets, semiconductor nanocrystals, and nanocrystal superlattices. Murray was recognized at IBM as a Master Inventor and patent evaluator. He holds at least 26 nanascale patents.
Murray is concerned with the synthesis and self-assembly properties of nanocrystals and the potential to create new mesoscopic materials with interesting properties and potential applications in energy, environmental sustainability, health, and information processing.
Murray is the Founding Chair of the World Economic Forum’s Global Councils on Nanotechnology (2008-2009) and Global Council on Emerging Technologies (2009-2010). | 0 | Theoretical and Fundamental Chemistry |
The crystal structure of green rust can be understood as the result of inserting the foreign anions and water molecules between brucite-like layers of iron(II) hydroxide, (). The latter has an hexagonal structure, with layer sequence AcBAcB... , where A and B are planes of hydroxide ions, and c those of (iron(II), ferrous) cations. In the green rust, some cations get oxidized to (iron(III), ferric). Each triple layer AcB, which is electrically neutral in the hydroxide, becomes positively charged. The anions then intercalate between those triple layers and restore neutrality.
There are two basic structures of green rust, "type 1" and "type 2". Type 1 is exemplified by the chloride and carbonate varieties. It has a rhombohedral crystal structure similar to that of pyroaurite. The layers are stacked in the sequence AcBiBaCjCbAkA ...; where A, B, and C represent planes, a, b, and c are layers of mixed and cations, and i, j, and k are layers of the intercalated anions and water molecules. The c crystallographic parameter is 22.5–22.8 Å for the carbonate, and about 24 Å for the chloride.
Type 2 green rust is exemplified by the sulfate variety. It has a hexagonal crystal structure, with layers probably stacked in the sequence AcBiAbCjA... | 1 | Applied and Interdisciplinary Chemistry |
Triazabicyclodecene (1,5,7-triazabicyclo[4.4.0]dec-5-ene or TBD) is an organic compound consisting of a bicyclic guanidine. For a charge-neutral compound, it is a relatively strong base that is effective for a variety of organic transformations. TBD is colorless solid that is soluble in a variety of solvents. | 0 | Theoretical and Fundamental Chemistry |
Tom filed at least five patents in the UK and two in the US. He invented and patented the technology used at Thornaby as the Whitwell Heating Stove. Over two hundred stoves were installed in over 70 furnaces around the globe. He also patented a continuous brick-burning kiln and a more efficient fire grate. | 1 | Applied and Interdisciplinary Chemistry |
With the advent of size exclusion chromatography (SEC), MALS measurements began to be used in conjunction with an on-line concentration detector to determine absolute molar mass and size of sample fractions eluting from the column, rather than depending on calibration techniques. These flow mode MALS measurements have been extended to other separation techniques such as field flow fractionation, ion exchange chromatography, and reversed-phase chromatography.
The angular dependence of light scattering data is shown below in a figure of mix of polystyrene spheres which was separated by SEC. The two smallest samples (farthest to the right) eluted last and show no angular dependence. The sample, second to the right shows a linear angular variation with the intensity increasing at lower scattering angles. The largest sample, on the left, elutes first and shows non-linear angular variation. | 0 | Theoretical and Fundamental Chemistry |
A ρ factor (Rho factor) is a bacterial protein involved in the termination of transcription. Rho factor binds to the transcription terminator pause site, an exposed region of single stranded RNA (a stretch of 72 nucleotides) after the open reading frame at C-rich/G-poor sequences that lack obvious secondary structure.
Rho factor is an essential transcription protein in bacteria. In Escherichia coli, it is a ~274.6 kD hexamer of identical subunits. Each subunit has an RNA-binding domain and an ATP-hydrolysis domain. Rho is a member of the RecA/SF5 family of ATP-dependent hexameric helicases that function by wrapping nucleic acids around a single cleft extending around the entire hexamer. Rho functions as an ancillary factor for RNA polymerase.
There are two types of transcriptional termination in bacteria, rho-dependent termination and intrinsic termination (also called Rho-independent termination). Rho-dependent terminators account for about half of the E. coli factor-dependent terminators. Other termination factors discovered in E. coli include Tau and nusA. Rho-dependent terminators were first discovered in bacteriophage genomes. | 1 | Applied and Interdisciplinary Chemistry |
In low gravity and dusty environments, such as the Moon, they can be created by the wheels of moving vehicles. A special energetic volcanic eruption known as a strombolian eruption produces bright arcs of ejecta, referred to as rooster tails, composed of basaltic cinders or volcanic ash. | 1 | Applied and Interdisciplinary Chemistry |
A lattice system is a group of lattices with the same set of lattice point groups. The 14 Bravais lattices are grouped into seven lattice systems: triclinic, monoclinic, orthorhombic, tetragonal, rhombohedral, hexagonal, and cubic. | 0 | Theoretical and Fundamental Chemistry |
Selenols have few commercial applications, being limited by the toxicity of selenium as well as the sensitivity of the bond. Their conjugate bases, the selenolates, also have limited applications in organic synthesis. | 0 | Theoretical and Fundamental Chemistry |
A peptidomimetic is a small protein-like chain designed to mimic a peptide. They typically arise either from modification of an existing peptide, or by designing similar systems that mimic peptides, such as peptoids and β-peptides. Irrespective of the approach, the altered chemical structure is designed to advantageously adjust the molecular properties such as stability or biological activity. This can have a role in the development of drug-like compounds from existing peptides. Peptidomimetics can be prepared by cyclization of linear peptides or coupling of stable unnatural amino acids. These modifications involve changes to the peptide that will not occur naturally (such as altered backbones and the incorporation of nonnatural amino acids). Unnatural amino acids can be generated from their native analogs via modifications such as amine alkylation, side chain substitution, structural bond extension cyclization, and isosteric replacements within the amino acid backbone. Based on their similarity with the precursor peptide, peptidomimetics can be grouped into four classes (A – D) where A features the most and D the least similarities. Classes A and B involve peptide-like scaffolds, while classes C and D include small molecules (Figure 1). | 0 | Theoretical and Fundamental Chemistry |
Sulfonyl fluorides have the general formula RSOF. They can be produced by treating sulfonic acids with sulfur tetrafluoride:
Perfluorooctanesulfonyl derivatives, such as PFOS, are produced from their sulfonyl fluoride, which are produced by electrofluorination
In the molecular biology, sulfonyl fluorides are used to label proteins. They specifically react with serine, threonine, tyrosine, lysine, cysteine, and histidine residues. The fluorides are more resistant than the corresponding chlorides and are therefore better suited to this task.
Some sulfonyl fluorides can also be used as deoxyfluorinating reagents, such as 2-pyridinesulfonyl fluoride (PyFluor) and N-tosyl-4-chlorobenzenesulfonimidoyl fluoride (SulfoxFluor). | 0 | Theoretical and Fundamental Chemistry |
Most free-living copepods feed directly on phytoplankton, catching cells individually. A single copepod can consume up to 373,000 phytoplankton per day. They generally have to clear the equivalent to about a million times their own body volume of water every day to cover their nutritional needs. Some of the larger species are predators of their smaller relatives. Many benthic copepods eat organic detritus or the bacteria that grow in it, and their mouth parts are adapted for scraping and biting. Herbivorous copepods, particularly those in rich, cold seas, store up energy from their food as oil droplets while they feed in the spring and summer on plankton blooms. These droplets may take up over half of the volume of their bodies in polar species. Many copepods (e.g., fish lice like the Siphonostomatoida) are parasites, and feed on their host organisms. In fact, three of the 10 known orders of copepods are wholly or largely parasitic, with another three comprising most of the free-living species. | 1 | Applied and Interdisciplinary Chemistry |
Pouring metal defects include misruns, cold shuts, and inclusions. A misrun occurs when the liquid metal does not completely fill the mould cavity, leaving an unfilled portion. Cold shuts occur when two fronts of liquid metal do not fuse properly in the mould cavity, leaving a weak spot. Both are caused by either a lack of fluidity in the molten metal or cross-sections that are too narrow. The fluidity can be increased by changing the chemical composition of the metal or by increasing the pouring temperature. Another possible cause is back pressure from improperly vented mould cavities.
Misruns and cold shuts are closely related and both involve the material freezing before it completely fills the mould cavity. These types of defects are serious because the area surrounding the defect is significantly weaker than intended. The castability and viscosity of the material can be important factors with these problems. Fluidity affects the minimum section thickness that can be cast, the maximum length of thin sections, fineness of feasibly cast details, and the accuracy of filling mould extremities. There are various ways of measuring the fluidity of a material, although it usually involves using a standard mould shape and measuring the distance the material flows. Fluidity is affected by the composition of the material, freezing temperature or range, surface tension of oxide films, and, most importantly, the pouring temperature. The higher the pouring temperature, the greater the fluidity; however, excessive temperatures can be detrimental, leading to a reaction between the material and the mould; in casting processes that use a porous mould material the material may even penetrate the mould material.
The point at which the material cannot flow is called the coherency point. The point is difficult to predict in mould design because it is dependent on the solid fraction, the structure of the solidified particles, and the local shear strain rate of the fluid. Usually this value ranges from 0.4 to 0.8.
An inclusion is a metal contamination of dross, if solid, or slag, if liquid. These usually are impurities in the pour metal (generally oxides, less frequently nitrides, carbides, or sulfides), material that is eroded from furnace or ladle linings, or contaminates from the mould. In the specific case of aluminium alloys, it is important to control the concentration of inclusions by measuring them in the liquid aluminium and taking actions to keep them to the required level.
There are a number of ways to reduce the concentration of inclusions. In order to reduce oxide formation the metal can be melted with a flux, in a vacuum, or in an inert atmosphere. Other ingredients can be added to the mixture to cause the dross to float to the top where it can be skimmed off before the metal is poured into the mould. If this is not practical, then a special ladle that pours the metal from the bottom can be used. Another option is to install ceramic filters into the gating system. Otherwise swirl gates can be formed which swirl the liquid metal as it is poured in, forcing the lighter inclusions to the center and keeping them out of the casting. If some of the dross or slag is folded into the molten metal then it becomes an entrainment defect. | 1 | Applied and Interdisciplinary Chemistry |
Various solutions have been proposed for the challenging problem of network motif (NM) discovery. These algorithms can be classified under various paradigms such as exact counting methods, sampling methods, pattern growth methods and so on. However, motif discovery problem comprises two main steps: first, calculating the number of occurrences of a sub-graph and then, evaluating the sub-graph significance. The recurrence is significant if it is detectably far more than expected. Roughly speaking, the expected number of appearances of a sub-graph can be determined by a Null-model, which is defined by an ensemble of random networks with some of the same properties as the original network.
Until 2004, the only exact counting method for NM detection was the brute-force one proposed by Milo et al.. This algorithm was successful for discovering small motifs, but using this method for finding even size 5 or 6 motifs was not computationally feasible. Hence, a new approach to this problem was needed.
Here, a review on computational aspects of major algorithms is given and their related benefits and drawbacks from an algorithmic perspective are discussed. | 1 | Applied and Interdisciplinary Chemistry |
Oxaziridines are intermediates in the peroxide process for the production of hydrazine. Many millions of kilograms of hydrazine are produced annually by this method that involves a step wherein ammonia is oxidized in the presence of methyl ethyl ketone to give the oxaziridine:
:Me(Et)C=O + NH + HO → Me(Et)CONH + HO
In subsequent steps the oxaziridine is converted to the hydrazone, which is the immediate in the way to hydrazine:
:Me(Et)CONH + NH → Me(Et)C=NNH + HO | 0 | Theoretical and Fundamental Chemistry |
Winkler published the methodology of a simple, accurate and direct dissolved oxygen analytical procedure in 1888. Since that time, the analysis of dissolved oxygen levels for water has been key to the determination of surface water. The Winkler method is still one of only two analytical techniques used to calibrate oxygen electrode meters; the other procedure is based on oxygen solubility at saturation as per Henry's law.
There are two recognized methods for the measurement of dissolved oxygen for BOD and a number of other methods not currently internationally recognised as standard methods | 0 | Theoretical and Fundamental Chemistry |
In fluid dynamics, the volumetric flux is the rate of volume flow across a unit area (m·s), and has dimensions of distance/time (volume/(time*area)) - equivalent to mean velocity. The density of a particular property in a fluids volume, multiplied with the volumetric flux of the fluid, thus defines the advective flux of that property. The volumetric flux through a porous medium is called superficial velocity and it is often modelled using Darcys law.
Volumetric flux is not to be confused with volumetric flow rate, which is the volume of fluid that passes through a given surface per unit of time (as opposed to a unit surface). | 1 | Applied and Interdisciplinary Chemistry |
The industrial processes vary depending on the chain length of the olefin to be hydroformylated, the catalyst metal and ligands, and the recovery of the catalyst. The original Ruhrchemie process produced propanal from ethene and syngas using cobalt tetracarbonyl hydride. Today, industrial processes based on cobalt catalysts are mainly used for the production of medium- to long-chain olefins, whereas the rhodium-based catalysts are usually used for the hydroformylation of propene. The rhodium catalysts are significantly more expensive than cobalt catalysts. In the hydroformylation of higher molecular weight olefins the separation of the catalyst from the produced aldehydes is difficult. | 0 | Theoretical and Fundamental Chemistry |
Bidirectional transcription at enhancer sites generates comparatively shorter (0.5-2kb) and non-polyadenylated eRNAs. Enhancers that generate polyA- eRNAs have a chromatin signature with a higher H3K4me1/me3 ratio than 1D-eRNAs. In general, enhancer transcription and production of bidirectional eRNAs demonstrate a strong correlation of enhancer activity on gene transcription. | 1 | Applied and Interdisciplinary Chemistry |
Symmetries are of prime importance in physics and are closely related to the hypothesis that certain physical quantities are only relative and unobservable. Symmetries apply to the equations that govern the physical laws (e.g. to a Hamiltonian or Lagrangian) rather than the initial conditions, values or magnitudes of the equations themselves and state that the laws remain unchanged under a transformation. If a symmetry is preserved under a transformation it is said to be invariant. Symmetries in nature lead directly to conservation laws, something which is precisely formulated by Noether's theorem. | 0 | Theoretical and Fundamental Chemistry |
In thermodynamics, the Gibbs–Duhem equation describes the relationship between changes in chemical potential for components in a thermodynamic system:
where is the number of moles of component the infinitesimal increase in chemical potential for this component, the entropy, the absolute temperature, volume and the pressure. is the number of different components in the system. This equation shows that in thermodynamics intensive properties are not independent but related, making it a mathematical statement of the state postulate. When pressure and temperature are variable, only of components have independent values for chemical potential and Gibbs' phase rule follows. The Gibbs−Duhem equation cannot be used for small thermodynamic systems due to the influence of surface effects and other microscopic phenomena.
The equation is named after Josiah Willard Gibbs and Pierre Duhem. | 0 | Theoretical and Fundamental Chemistry |
Some SELEX reactions can generate probes that are dependent on primer binding regions for secondary structure formation. There are aptamer applications for which a short sequence, and thus primer truncation, is desirable. An advancement on the original method allows an RNA library to omit the constant primer regions, which can be difficult to remove after the selection process because they stabilize secondary structures that are unstable when formed by the random region alone. | 1 | Applied and Interdisciplinary Chemistry |
There are several ways to approach the topic of premelting, the most figurative way might be thermodynamically. A more detailed or abstract view on what physics is important for premelting is given by the Lifshitz and the Landau theories.
One always starts with looking at a crystalline solid phase (fig. 1: (1) solid) and another phase. This second phase (fig. 1: (2)) can either be vapour, liquid or solid. Further it can consist of the same chemical material or another. In the case of the second phase being a solid of the same chemical material one speaks of grain boundaries. This case is very important when looking at polycrystalline materials. | 0 | Theoretical and Fundamental Chemistry |
Boric acid esters derived from glycols (example, organo-borate formulation, Biobor JF) are being used for the control of microorganisms in fuel systems containing water. | 1 | Applied and Interdisciplinary Chemistry |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.