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Fast protein liquid chromatography (FPLC) is a form of liquid chromatography that is often used to analyze or purify mixtures of proteins. As in other forms of chromatography, separation is possible because the different components of a mixture have different affinities for two materials, a moving fluid (the mobile phase) and a porous solid (the stationary phase). In FPLC the mobile phase is an aqueous buffer solution. The buffer flow rate is controlled by a positive-displacement pump and is normally kept constant, while the composition of the buffer can be varied by drawing fluids in different proportions from two or more external reservoirs. The stationary phase is a resin composed of beads, usually of cross-linked agarose, packed into a cylindrical glass or plastic column. FPLC resins are available in a wide range of bead sizes and surface ligands depending on the application.
FPLC was developed and marketed in Sweden by Pharmacia in 1982, and was originally called fast performance liquid chromatography to contrast it with high-performance liquid chromatography (HPLC). FPLC is generally applied only to proteins; however, because of the wide choice of resins and buffers it has broad applications. In contrast to HPLC, the buffer pressure used is relatively low, typically less than 5 bar, but the flow rate is relatively high, typically 1–5 ml/min.
FPLC can be readily scaled from analysis of milligrams of mixtures in columns with a total volume of 5 ml or less to industrial production of kilograms of purified protein in columns with volumes of many liters. When used for analysis of mixtures, the eluant is usually collected in fractions of 1–5 ml which can be further analyzed. When used for protein purification there may be only two collection containers: one for the purified product and one for waste. | 0 | Theoretical and Fundamental Chemistry |
The SQT incorporates three lines of evidence (LOE) to provide direct assessment of sediment quality. The chemistry, toxicity, and benthic components of the triad each provide a LOE, which is then integrated into a Weight of evidence. | 1 | Applied and Interdisciplinary Chemistry |
Apart from these advantages, there are several disadvantages needed to take into considerations. The plant integrating Ca-Looping might require a high construction investment because of the high thermal power of the post-combustion calcium loop. The sorbent capacity decreases significantly with the number of cycles for every carbonation-calcination cycle so the calcium-looping unit will require a constant flow of limestone. In order to increase the long-term reactivity of the sorbent or to reactivate the sorbent, some methods are under investigation such as thermal pretreatment, chemical doping and the production of artificial sorbents. The method applying the concept of fluidized bed reactor, but there are some problems causing the uncertainty for the process. Attrition of the limestone can be a problem during repeated cycling. | 1 | Applied and Interdisciplinary Chemistry |
The CD V-700, as a true Geiger counter, is capable of measuring ambient background levels of gamma radiation and detecting the presence of beta radiation in the environment, and thus can be used to detect such common low-level radioactive artifacts as uranium-doped marbles, Fiestaware plates and radium watch faces. This differentiates them from other civil defense radiation meters such as the CD V-715, CD V-717 and CD-V-720, which are ion chamber meters that can measure gamma radiation levels far above (up to 500R/h) what the CD V-700 can (up to 50mR/h). Conversely, the ion chamber units are so insensitive to low-levels of gamma radiation that no legally exempt radiation source can make them register at all.
The CD V-700s were usually packaged in various combinations with the high-level ion chamber units as listed above in kits designated CD V-777. In their original Cold War application, the sensitive CD V-700s would be saturated and thus rendered useless by the high radiation levels expected after an exchange of nuclear weapons. In that setting, it would be the ion chamber units that received most of the use. The CD V-700s main purpose was as a peacetime training instrument and for use in checking food and shelter entrances for low levels of fallout contamination. Later, as the Cold War mission wound down, many CD V-700s were re-purposed as instruments for first responders to use at the scene of a radiological event or other incident.
As the CD V-700s produced for the US government are now over 50 years old, they are being slowly replaced by more modern instrumentation in US federal and state government stockpiles and these older units are being sold off as government surplus. This makes them inexpensive and very common in the US for use by uranium prospectors, physics teachers, radiation hobbyists and others interested in detecting and measuring ionizing radiation.
CD V-700s are relatively simple devices, with a circuit board that employs a few dozen electronics components, at most. Thus, the CD V-700 is a common target for various upgrades and modifications that enable added functionality. Most of the parts used are common off-the-shelf electronics parts, but some models employ transformers and other parts that were custom-made just for that particular make and model of CD V-700 and these can be difficult to locate and replace in the event of a failure. Considering their age, the CD V-700 is a fairly reliable device and are usually fairly easy to keep operational over time.
The battery limits the range of temperature at which the device works from between −10 degrees C and 40 degrees C. | 0 | Theoretical and Fundamental Chemistry |
In attempt to reduce the high nuisance alarm rates of first generation RPMs, the Advanced Spectroscopic Portal (ASP) program was called into life. Some of the portal monitors evaluated for this purposes are based on NaI(Tl) scintillating crystals. These devices, having better energy resolution than PVT, were supposed to reduce nuisance alarm rates by distinguishing threats from benign sources on the basis of the detected gamma radiation spectra. ASPs based on NaI(Tl) had a cost several times that of first generation RPMs. To date, NaI(Tl) based ASPs have not been able to demonstrate significantly better performance than PVT based RPMs.
The ASP program was canceled in 2011 after continued problems, including a high rate of false positives and difficulty maintaining stable operation. | 0 | Theoretical and Fundamental Chemistry |
In analytical chemistry, cross-validation is an approach by which the sets of scientific data generated using two or more methods are critically assessed. The cross-validation can be categorized as either method validation or analytical data validation. | 0 | Theoretical and Fundamental Chemistry |
The biological term symbiosis was first used in chemistry by C. K. Jørgensen in 1964, to refer to the process by which a hard ligand on a metal predisposes the metal to receive another hard ligand rather than a soft one. Two superficially antithetical phenomena occur: symbiosis and antisymbiosis. | 0 | Theoretical and Fundamental Chemistry |
As mentioned above, changes in MITF can result in serious health conditions. For example, mutations of MITF have been implicated in both Waardenburg syndrome and Tietz syndrome.
Waardenburg syndrome is a rare genetic disorder. Its symptoms include deafness, minor defects, and abnormalities in pigmentation. Mutations in the MITF gene have been found in certain patients with Waardenburg syndrome, type II. Mutations that change the amino acid sequence of that result in an abnormally small MITF are found. These mutations disrupt dimer formation, and as a result cause insufficient development of melanocytes. The shortage of melanocytes causes some of the characteristic features of Waardenburg syndrome.
Tietz syndrome, first described in 1923, is a congenital disorder often characterized by deafness and leucism. Tietz is caused by a mutation in the MITF gene. The mutation in MITF deletes or changes a single amino acid base pair specifically in the base motif region of the MITF protein. The new MITF protein is unable to bind to DNA and melanocyte development and subsequently melanin production is altered. A reduced number of melanocytes can lead to hearing loss, and decreased melanin production can account for the light skin and hair color that make Tietz syndrome so noticeable. | 1 | Applied and Interdisciplinary Chemistry |
Surgical usage of 3D printing has evolved from printing surgical instrumentation to the development of patient-specific technologies for total joint replacements, dental implants, and hearing aids. In the field of organ printing, applications can be applied for patients and surgeons. For instance, printed organs have been used to model structure and injury to better understand the anatomy and discuss a treatment regime with patients. For these cases, the functionality of the organ is not required and is used for proof-of-concept. These model organs provide advancement for improving surgical techniques, training inexperienced surgeons, and moving towards patient-specific treatments. | 1 | Applied and Interdisciplinary Chemistry |
Air pollutants generated by aluminium smelters include carbonyl sulfide, hydrogen fluoride, polycyclic compounds, lead, nickel, manganese, polychlorinated biphenyls, and mercury. Copper smelter emissions include arsenic, beryllium, cadmium, chromium, lead, manganese, and nickel. Lead smelters typically emit arsenic, antimony, cadmium and various lead compounds. | 1 | Applied and Interdisciplinary Chemistry |
Steps are also being taken in academia and industry to use this hyperpolarized gas for lung imaging. Once the gas (Xe) is hyperpolarized through the SEOP process and the alkali metal is removed, a patient (either healthy or suffering from a lung disease), can breathe in the gas and an MRI can be taken. This results in an image of the spaces in the lungs filled with the gas. While the process to get to the point of imaging the patient may require knowledge from scientists very familiar with this technique and the equipment, steps are being taken to eliminate the need for this knowledge so that a hospital technician would be able to produce the hyperpolarized gas using a polarizer.
Hyperpolarization machines are currently being used to develop hyperpolarized xenon gas that is used as a visualization agent for the lungs. Xenon-129 is a safe inert noble gas that can be used to quantify lung function. With a single 10-second breath hold, hyperpolarized Xenon-129 is used with MRI to enable 3-dimensional lung imaging. Xenon MRI is being used to monitor patients with pulmonary-vascular, obstructive, or fibrotic lung disease.
Temperature-ramped Xe SEOP in an automated high-output batch model hyperpolarized Xe can utilize three prime temperature range to put certain conditions: First, Xe hyperpolarization rate is superlative high at hot condition. Second, in warm condition the hyperpolarization of Xe is unity. Third, at cold condition, the level of hyperpolarization of Xe gas at least can get the (at human body's temperature) imaging although during the transferring into the Tedlar bag having poor percentage of Rb (less than 5 ng/L dose).
Multiparameter analysis of Rb/Xe SEOP at high xenon pressure and photon flux could be used as 3D-printing and stopped flow contrasting agent in clinical scale. In situ technique, the NMR machine was run for tracking the dynamics of Xe polarization as a function of SEOP-cell conditioning with different operating parameters such as data collecting temperature, photon flux, and Xe partial pressure to enhance the Xe polarization (P).
All of those polarization values of Xe has been approved by pushing the hyperpolarized Xe gas and all MRI experiment also done at lower magnetic field 47.5 mT. Finally demonstrations indicated that such a high pressure region, polarization of Xe gases could be increment even more that the limit that already has been shown. Better SEOP thermal management and optimizing the polarizing kinetics has been further improved with good efficacy. | 0 | Theoretical and Fundamental Chemistry |
The word ester was coined in 1848 by a German chemist Leopold Gmelin, probably as a contraction of the German , "acetic ether". | 0 | Theoretical and Fundamental Chemistry |
The simplest and most commonly encountered of the phosphoric acids is orthophosphoric acid, . Indeed, the term phosphoric acid often means this compound specifically (and this is also the current IUPAC nomenclature). | 0 | Theoretical and Fundamental Chemistry |
Colored dissolved organic matter (CDOM) is estimated to range 20-70% of carbon content of the oceans, being higher near river outlets and lower in the open ocean.
Marine life is largely similar in biochemistry to terrestrial organisms, except that they inhabit a saline environment. One consequence of their adaptation is that marine organisms are the most prolific source of halogenated organic compounds. | 0 | Theoretical and Fundamental Chemistry |
Polanyi's theory has historical significance whose work has been used a foundation for other models, such as the theory of volume filling micropores (TVFM) and the Dubinin–Radushkevich theory.
Other research have been performed loosely involving the potential theory of Polanyi such as the capillary condensation phenomenon discovered by Zsigmondy. Unlike Poylanis theory which involves a flat surface, Zsigmondys research involves a porous structure like silica materials. His research proved that condensation of vapors can occur in narrow pores below the standard saturated vapour pressure. | 0 | Theoretical and Fundamental Chemistry |
The large demand for cyanides for mining operations in the 1890s was met by George Thomas Beilby, who patented a method to produce hydrogen cyanide by passing ammonia over glowing coal in 1892. This method was used until Hamilton Castner in 1894 developed a synthesis starting from coal, ammonia, and sodium yielding sodium cyanide, which reacts with acid to form gaseous HCN. | 0 | Theoretical and Fundamental Chemistry |
Various microorganisms are involved in a two-stage process of degradation of PCBs, which happens in aerobic and anaerobic environments. Degrading PCBs is similar to the degradation of biphenyl. However, the chlorines on PCBs prevent them from being utilized as a substrate of biphenyl degradation. Due to high chemical stability, PCBs cannot be used as energy sources. However, due to the chlorination, PCBs can be used as electron acceptors in anaerobic respiration to store energy, which is also the first stage of the degradation pathway, reductive dechlorination. Once the PCBs are dechlorinated to a certain degree, usually lower than five chlorines presenting in the structure and one aromatic ring has no chlorine, they can undergo the biphenyl degradation pathway (BP pathway) to be degraded to accessible carbon or CO in the aerobic environment. BP pathway is a pathway that utilizes series of enzymes (BphA, B, C, D, E, F, G) to convert biphenyl to TCA cycle intermediates (pyruvate and Acyl-CoA) and benzoate. However, there are few microorganisms that can dechlorinate substrate under natural conditions. Even with selective media, the accumulation of PCB dechlorinating microorganisms is still slow, which is one reason for the slow degradation rate. As a result, PCBs usually go through a co-metabolism pathway that involving different microorganism species.
Generally speaking, there are four steps in this process:
# In order for PCBs to enter the cell, they firstly need to be solubilized.
# PCBs are dechlorinated by anaerobic bacteria, then transport the metabolites to aerobic bacteria or fungi through a biofilm.
# The presence of PCBs metabolites triggers the expression of enzymes in BP pathway.
# PCBs are broken down to Acetyl-CoA and then can be utilized or carbon dioxide.
The Figure below shows the complete degradation pathway. | 1 | Applied and Interdisciplinary Chemistry |
In traditional drug delivery systems such as oral ingestion or intravascular injection, the medication is distributed throughout the body through the systemic blood circulation. For most therapeutic agents, only a small portion of the medication reaches the organ to be affected, such as in chemotherapy where roughly 99% of the drugs administered do not reach the tumor site. Targeted drug delivery seeks to concentrate the medication in the tissues of interest while reducing the relative concentration of the medication in the remaining tissues. For example, by avoiding the host's defense mechanisms and inhibiting non-specific distribution in the liver and spleen, a system can reach the intended site of action in higher concentrations. Targeted delivery is believed to improve efficacy while reducing side-effects.
When implementing a targeted release system, the following design criteria for the system must be taken into account: the drug properties, side-effects of the drugs, the route taken for the delivery of the drug, the targeted site, and the disease.
Increasing developments to novel treatments requires a controlled microenvironment that is accomplished only through the implementation of therapeutic agents whose side-effects can be avoided with targeted drug delivery. Advances in the field of targeted drug delivery to cardiac tissue will be an integral component to regenerate cardiac tissue.
There are two kinds of targeted drug delivery: active targeted drug delivery, such as some antibody medications, and passive targeted drug delivery, such as the enhanced permeability and retention effect (EPR-effect). | 1 | Applied and Interdisciplinary Chemistry |
From IAEA TECDOC-1450 "Thorium Fuel Cycle – Potential Benefits and Challenges", Table 1: Thorium utilization in different experimental and power reactors. Additionally from Energy Information Administration, "Spent Nuclear Fuel Discharges from U. S. Reactors", Table B4: Dresden 1 Assembly Class. | 0 | Theoretical and Fundamental Chemistry |
An ideal solid surface is flat, rigid, perfectly smooth, and chemically homogeneous, and has zero contact angle hysteresis. Zero hysteresis implies the advancing and receding contact angles are equal.
In other words, only one thermodynamically stable contact angle exists. When a drop of liquid is placed on such a surface, the characteristic contact angle is formed as depicted in Fig. 1. Furthermore, on an ideal surface, the drop will return to its original shape if it is disturbed. The following derivations apply only to ideal solid surfaces; they are only valid for the state in which the interfaces are not moving and the phase boundary line exists in equilibrium. | 0 | Theoretical and Fundamental Chemistry |
The field of thermodynamics describes when vapor–liquid equilibrium is possible, and its properties. Much of the analysis depends on whether the vapor and liquid consist of a single component, or if they are mixtures. | 0 | Theoretical and Fundamental Chemistry |
From a practical view, low-melting alloys can be divided into the following categories:
*Mercury-containing alloys
*Only alkali metal-containing alloys
*Gallium-containing alloys (but neither alkali metal nor mercury)
*Only bismuth, lead, tin, cadmium, zinc, indium, and sometimes thallium-containing alloys
*Other alloys (rarely used)
Some reasonably well-known fusible alloys are Woods metal, Fields metal, Rose metal, Galinstan, and NaK. | 1 | Applied and Interdisciplinary Chemistry |
The dispersion or diffraction is only controllable if the light is collimated, that is if all the rays of light are parallel, or practically so. A source, like the sun, which is very far away, provides collimated light. Newton used sunlight in his famous experiments. In a practical monochromator, however, the light source is close by, and an optical system in the monochromator converts the diverging light of the source to collimated light. Although some monochromator designs do use focusing gratings that do not need separate collimators, most use collimating mirrors. Reflective optics are preferred because they do not introduce dispersive effects of their own. | 0 | Theoretical and Fundamental Chemistry |
When a neutral atom collides with an ion in a gas or a plasma, the ion can acquire an electron from the neutral atom as both electron shells overlap in the course of the collision. This can be used in various applications. | 0 | Theoretical and Fundamental Chemistry |
Demethylation of 5-methylcytosine to generate 5-hydroxymethylcytosine (5hmC) very often initially involves oxidation of 5mC (see Figure in this section) by ten-eleven translocation methylcytosine dioxygenases (TET enzymes). The molecular steps of this initial demethylation are shown in detail in TET enzymes. In successive steps (see Figure) TET enzymes further hydroxylate 5hmC to generate 5-formylcytosine (5fC) and 5-carboxylcytosine (5caC). Thymine-DNA glycosylase (TDG) recognizes the intermediate bases 5fC and 5caC and excises the glycosidic bond resulting in an apyrimidinic site (AP site). This is followed by base excision repair (stage 3). In an alternative oxidative deamination pathway, 5hmC can be oxidatively deaminated by APOBEC (AID/APOBEC) deaminases to form 5-hydroxymethyluracil (5hmU). Also, 5mC can be converted to thymine (Thy). 5hmU can be cleaved by TDG, MBD4, NEIL1 or SMUG1. AP sites and T:G mismatches are then repaired by base excision repair (BER) enzymes to yield cytosine (Cyt). The TET family of dioxygenases are employed in the most frequent type of demethylation reactions. | 1 | Applied and Interdisciplinary Chemistry |
* Ames test – This is the most commonly used test, and Salmonella typhimurium strains deficient in histidine biosynthesis are used in this test. The test checks for mutants that can revert to wild-type. It is an easy, inexpensive and convenient initial screen for mutagens.
* Resistance to 8-azaguanine in S. typhimurium – Similar to Ames test, but instead of reverse mutation, it checks for forward mutation that confer resistance to 8-Azaguanine in a histidine revertant strain.
* Escherichia coli systems – Both forward and reverse mutation detection system have been modified for use in E. coli. Tryptophan-deficient mutant is used for the reverse mutation, while galactose utility or resistance to 5-methyltryptophan may be used for forward mutation.
* DNA repair – E. coli and Bacillus subtilis strains deficient in DNA repair may be used to detect mutagens by their effect on the growth of these cells through DNA damage. | 0 | Theoretical and Fundamental Chemistry |
Just as absolute entropy serves as theoretical background for data compression, relative entropy serves as theoretical background for data differencing – the absolute entropy of a set of data in this sense being the data required to reconstruct it (minimum compressed size), while the relative entropy of a target set of data, given a source set of data, is the data required to reconstruct the target given the source (minimum size of a patch). | 0 | Theoretical and Fundamental Chemistry |
In physics, the Toda oscillator is a special kind of nonlinear oscillator. It represents a chain of particles with exponential potential interaction between neighbors. These concepts are named after Morikazu Toda. The Toda oscillator is used as a simple model to understand the phenomenon of self-pulsation, which is a quasi-periodic pulsation of the output intensity of a solid-state laser in the transient regime. | 0 | Theoretical and Fundamental Chemistry |
Zintl ions are typically prepared through one of two methods. The first is a direct reduction route performed at low temperature. In this method, dry ammonia is condensed over a mixture of the two (or more) metals under inert atmosphere. The reaction initially produces solvated electrons in ammonia that reduce the more electronegative element over the course of the reaction. This reaction can be monitored by a color change from blue (solvated electrons) to the color of the Zintl phase. The second is method, performed at higher temperatures, is to dissolve a Zintl phase in liquid ammonia or other polar aprotic solvent like ethylenediamine (on rare occasions DMF or pyridine is used). Some Zintl ions, such as Si and Ge based ions, can only be prepared via this indirect method because they cannot be reduced at low temperatures. | 0 | Theoretical and Fundamental Chemistry |
Some pharmaceuticals can initiate allergic reactions, as in the case of penicillins. In some people, administration of penicillin can induce production of specific antibodies and initiate an immune response. Activation of this response when unwarranted can cause severe health concerns and prevent proper immune system functioning. Immune responses to pharmaceutical exposure can be very common in accidental contamination events. Tamoxifen, a selective estrogen receptor modulator, has been shown to alter the humoral adaptive immune response in gilthead seabream. In this case, pharmaceuticals can produce adverse effects not only in humans, but also in organisms that are unintentionally exposed. | 1 | Applied and Interdisciplinary Chemistry |
Although it is generally accepted that vanilla was domesticated in Mesoamerica and subsequently spread to the Old World in the 16th century, in 2019, researchers published a paper stating that vanillin residue had been discovered inside jars within a tomb in Israel dating to the 2nd millennium BCE, suggesting the possible cultivation of an unidentified, Old World-endemic Vanilla species in Canaan since the Middle Bronze Age. Traces of vanillin were also found in wine jars in Jerusalem, which were used by the Judahite elite before the city was destroyed in 586 BCE.
Vanilla beans, called tlilxochitl, were discovered and cultivated as a flavoring for beverages by native Mesoamerican peoples, most famously the Totonacs of modern-day Veracruz, Mexico. Since at least the early 15th century, the Aztecs used vanilla as a flavoring for chocolate in drinks called xocohotl.
Vanillin was first isolated as a relatively pure substance in 1858 by Théodore Nicolas Gobley, who obtained it by evaporating a vanilla extract to dryness and recrystallizing the resulting solids from hot water. In 1874, the German scientists Ferdinand Tiemann and Wilhelm Haarmann deduced its chemical structure, at the same time finding a synthesis for vanillin from coniferin, a glucoside of isoeugenol found in pine bark. Tiemann and Haarmann founded a company Haarmann and Reimer (now part of Symrise) and started the first industrial production of vanillin using their process (now known as the Reimer–Tiemann reaction) in Holzminden, Germany. In 1876, Karl Reimer synthesized vanillin (2) from guaiacol (1).
By the late 19th century, semisynthetic vanillin derived from the eugenol found in clove oil was commercially available.
Synthetic vanillin became significantly more available in the 1930s, when production from clove oil was supplanted by production from the lignin-containing waste produced by the sulfite pulping process for preparing wood pulp for the paper industry. By 1981, a single pulp and paper mill in Thorold, Ontario, supplied 60% of the world market for synthetic vanillin. However, subsequent developments in the wood pulp industry have made its lignin wastes less attractive as a raw material for vanillin synthesis. Today, approximately 15% of the world's production of vanillin is still made from lignin wastes, while approximately 85% synthesized in a two-step process from the petrochemical precursors guaiacol and glyoxylic acid.
Beginning in 2000, Rhodia began marketing biosynthetic vanillin prepared by the action of microorganisms on ferulic acid extracted from rice bran. At USD$700/kg, this product, sold under the trademarked name Rhovanil Natural, is not cost-competitive with petrochemical vanillin, which sells for around US$15/kg. However, unlike vanillin synthesized from lignin or guaiacol, it can be labeled as a natural flavoring. | 0 | Theoretical and Fundamental Chemistry |
Photaki was born in Corinth in 1921 and finished her secondary education at the 2nd Girls Gymnasium of Athens in 1938. In the same year she enrolled at the Department of Chemistry in the University of Athens, where she specialised in Organic chemistry under the mentorship of Leonidas Zervas. Her studies were interrupted during the Axis occupation of Greece when the Laboratory of Organic Chemistry was destroyed and Zervas was imprisoned as a member of the Greek Resistance. Photaki was finally awarded her degree summa cum laude' in 1946 and subsequently continued her postgraduate studies under Zervas, earning her PhD in 1950 with a dissertation regarding glucosamine. Concurrently, she held a paid laboratory assistant position at the university already from 1943, carrying on as a research assistant until 1953.
In 1953, Photaki was awarded a scholarship to conduct research in Basel after examinations by the Greek State Scholarships Foundation. At the University of Basel she worked in the Laboratory of Organic Chemistry, at the time headed by Nobel laureate Tadeusz Reichstein. For the first two years of her stay (1953–1955) she was part of the Max Brenner research group, later moving as an independent scientific associate of Hans Erlenmeyer. Upon returning to Greece, she initially worked at the biochemical lab of the Evangelismos Hospital before being invited by Zervas to the nascent National Hellenic Research Foundation (NHRF) which he had helped found. | 0 | Theoretical and Fundamental Chemistry |
Living green roofs have been built and grown at Saint Michael's Sustainable Community since 2012. Native plants, mostly flowers chosen for the environment, maximum shade and mass provide a colorful and functional living roof. The community has the largest number of green roofs in the country. | 1 | Applied and Interdisciplinary Chemistry |
Euhedral crystals (also known as idiomorphic or automorphic crystals) are those that are well-formed, with sharp, easily recognised faces. The opposite is anhedral (also known as xenomorphic or allotriomorphic): a rock with an anhedral texture is composed of mineral grains that have no well-formed crystal faces or cross-section shape in thin section. Anhedral crystal growth occurs in a competitive environment with no free space for the formation of crystal faces. An intermediate texture with some crystal face-formation is termed subhedral (also known as hypidiomorphic or hypautomorphic).
Crystals that grow from cooling liquid magma typically do not form smooth faces or sharp crystal outlines. As magma cools, the crystals grow and eventually touch each other, preventing crystal faces from forming properly or at all.
When snowflakes crystallize, they do not touch each other. Thus, snowflakes form euhedral, six-sided twinned crystals. In rocks, the presence of euhedral crystals may signify that they formed early in the crystallization of liquid magma or perhaps crystallized in a cavity or vug, without steric hindrance, or spatial restrictions, from other crystals. | 0 | Theoretical and Fundamental Chemistry |
In other less formal contexts, an alcohol is often called with the name of the corresponding alkyl group followed by the word "alcohol", e.g., methyl alcohol, ethyl alcohol. Propyl alcohol may be n-propyl alcohol or isopropyl alcohol, depending on whether the hydroxyl group is bonded to the end or middle carbon on the straight propane chain. As described under systematic naming, if another group on the molecule takes priority, the alcohol moiety is often indicated using the "hydroxy-" prefix.
In archaic nomenclature, alcohols can be named as derivatives of methanol using "-carbinol" as the ending. For instance, can be named trimethylcarbinol. | 0 | Theoretical and Fundamental Chemistry |
Plasma transferred wire arc (PTWA) is another form of wire arc spray which deposits a coating on the internal surface of a cylinder, or on the external surface of a part of any geometry. It is predominantly known for its use in coating the cylinder bores of an engine, enabling the use of Aluminum engine blocks without the need for heavy cast iron sleeves. A single conductive wire is used as "feedstock" for the system. A supersonic plasma jet melts the wire, atomizes it and propels it onto the substrate. The plasma jet is formed by a transferred arc between a non-consumable cathode and the type of a wire. After atomization, forced air transports the stream of molten droplets onto the bore wall. The particles flatten when they impinge on the surface of the substrate, due to the high kinetic energy. The particles rapidly solidify upon contact. The stacked particles make up a high wear resistant coating. The PTWA thermal spray process utilizes a single wire as the feedstock material. All conductive wires up to and including 0.0625" (1.6mm) can be used as feedstock material, including "cored" wires. PTWA can be used to apply a coating to the wear surface of engine or transmission components to replace a bushing or bearing. For example, using PTWA to coat the bearing surface of a connecting rod offers a number of benefits including reductions in weight, cost, friction potential, and stress in the connecting rod. | 1 | Applied and Interdisciplinary Chemistry |
The fine structure in C radioactivity of Ra was discussed for the first time by M. Greiner and W. Scheid in 1986.
The superconducting spectrometer SOLENO of IPN Orsay has been used since 1984 to identify C clusters emitted from Ra nuclei. Moreover, it was used to discover
the fine structure observing transitions to excited states of the daughter. A transition with an excited state of C predicted in Ref. was not yet observed.
Surprisingly, the experimentalists had seen a transition to the first excited state of the daughter stronger than that to the ground state. The transition is favoured if the uncoupled nucleon is left in the same state in both parent and daughter nuclei. Otherwise the difference in nuclear structure leads to a large hindrance.
The interpretation
was confirmed: the main spherical component of the deformed parent wave function has an i character, i.e. the main component is spherical. | 0 | Theoretical and Fundamental Chemistry |
In semiconductors, the Shockley diode equation—the relationship between the flow of electric current and the electrostatic potential across a p–n junction—depends on a characteristic voltage called the thermal voltage, denoted by . The thermal voltage depends on absolute temperature as
where is the magnitude of the electrical charge on the electron with a value Equivalently,
At room temperature , is approximately which can be derived by plugging in the values as follows:
At the standard state temperature of , it is approximately . The thermal voltage is also important in plasmas and electrolyte solutions (e.g. the Nernst equation); in both cases it provides a measure of how much the spatial distribution of electrons or ions is affected by a boundary held at a fixed voltage. | 0 | Theoretical and Fundamental Chemistry |
Neurogranin is a calmodulin-binding protein expressed primarily in the brain, particularly in dendritic spines, and participating in the protein kinase C signaling pathway. Neurogranin has recently been found in aortic endothelial cells and cardiomyocytes. Neurogranin is the main postsynaptic protein regulating the availability of calmodulin, binding to it in the absence of calcium. Phosphorylation by protein kinase C lowers its binding ability. NRGN gene expression is controlled by thyroid hormones. Human neurogranin consists of 78 amino acids.
One study tells of potential link of neurogranin gene to the heightened risk of schizophrenia in males, another study gives evidence of lowered neurogranin immunoreactivity in the brains of people suffering from schizophrenia.
Neurogranin concentration in cerebrospinal fluid (CSF) is further discussed as marker for synaptic dysfunction in age-related neurodegeneration. It has also been shown to be specifically increased in patients with Alzheimers disease. Especially the ratio of CSF neurogranin trunc P75 and the beta-secretase BACE1 is suggested as potential marker for cognitive deterioration in the progress of Alzheimers disease.
Prior to its identification in the bovine and rat brain in 1991, neurogranin was known as a putative protein kinase C-phosphorylated protein named p17. Human neurogranin was cloned in 1997 and turned out to be 96% identical to the rat protein. | 1 | Applied and Interdisciplinary Chemistry |
Mass balances can be performed across systems which have cyclic flows. In these systems output streams are fed back into the input of a unit, often for further reprocessing.
Such systems are common in grinding circuits, where grain is crushed then sieved to only allow fine particles out of the circuit and the larger particles are returned to the roller mill (grinder). However, recycle flows are by no means restricted to solid mechanics operations; they are used in liquid and gas flows, as well. One such example is in cooling towers, where water is pumped through a tower many times, with only a small quantity of water drawn off at each pass (to prevent solids build up) until it has either evaporated or exited with the drawn off water. The mass balance for water is .
The use of the recycle aids in increasing overall conversion of input products, which is useful for low per-pass conversion processes (such as the Haber process). | 1 | Applied and Interdisciplinary Chemistry |
* Williams, H. (trans.), A sixteenth-century German treatise: Von Stahel und Eysen. 1532, Technical studies in the field of the fine arts, 4.2 (October, 1935), 63-92.
* Smith, Cyril Stanley (ed.), Sources for the History of the Science of Steel, 1532-1786, Society for the History of Technology, 4 (Cambridge, Mass.: Society for the History of Technology, 1968), pp. 7–19. | 1 | Applied and Interdisciplinary Chemistry |
Materials science has applied the techniques of combinatorial chemistry to the discovery of new materials. This work was pioneered by P.G. Schultz et al. in the mid-nineties in the context of luminescent materials obtained by co-deposition of elements on a silicon substrate. His work was preceded by J. J. Hanak in 1970 but the computer and robotics tools were not available for the method to spread at the time. Work has been continued by several academic groups as well as companies with large research and development programs (Symyx Technologies, GE, Dow Chemical etc.). The technique has been used extensively for catalysis, coatings, electronics, and many other fields. The application of appropriate informatics tools is critical to handle, administer, and store the vast volumes of data produced. New types of design of experiments methods have also been developed to efficiently address the large experimental spaces that can be tackled using combinatorial methods. | 1 | Applied and Interdisciplinary Chemistry |
Schwab was also known as a writer of physical chemistry and catalysis textbooks, with important works such as the Physico-chemical Foundations of Chemical Technology (, 1928) or Catalysis from the Standoint of Chemical Kinetics (, 1931), the English translation of which was a standard textbook on catalysis for decades. He was the editor of all 7 volumes of the international Handbook of Catalysis (1940–1960). | 0 | Theoretical and Fundamental Chemistry |
In chemistry, water(s) of crystallization or water(s) of hydration are water molecules that are present inside crystals. Water is often incorporated in the formation of crystals from aqueous solutions. In some contexts, water of crystallization is the total mass of water in a substance at a given temperature and is mostly present in a definite (stoichiometric) ratio. Classically, "water of crystallization" refers to water that is found in the crystalline framework of a metal complex or a salt, which is not directly bonded to the metal cation.
Upon crystallization from water, or water-containing solvents, many compounds incorporate water molecules in their crystalline frameworks. Water of crystallization can generally be removed by heating a sample but the crystalline properties are often lost.
Compared to inorganic salts, proteins crystallize with large amounts of water in the crystal lattice. A water content of 50% is not uncommon for proteins. | 0 | Theoretical and Fundamental Chemistry |
The Lunar Library, launched on the Beresheet Lander by the Arch Mission Foundation, carries information encoded in DNA, which includes 20 famous books and 10,000 images. This was one of the optimal choices of storage, as DNA can last a long time. The Arch Mission Foundation suggests that it can still be read after billions of years. | 1 | Applied and Interdisciplinary Chemistry |
Archaea do not generally have an F-ATPase. Instead, they synthesize ATP using the A-ATPase/synthase, a rotary machine structurally similar to the V-ATPase but mainly functioning as an ATP synthase. Like the bacteria F-ATPase, it is believed to also function as an ATPase. | 0 | Theoretical and Fundamental Chemistry |
A unit related to the SCCM is the SLM or SLPM which stands for Standard litre per minute. Their conversion is
and
Another unit is the SCFM which stands for standard cubic feet per minute.
Yet another unit related to SCCM (and SLM) is the PCCM (and PLM) which stands for Perfect Cubic Centimeter per Minute (Perfect Litre per Minute). One PCCM is one SCCM when the gas is ideal. In other words, one PCCM is exactly the same as one SCCM if and only if in the above relationships. | 1 | Applied and Interdisciplinary Chemistry |
Hydrometeor loading is the induced drag effects on the atmosphere from a falling hydrometeor. When falling at terminal velocity, the value of this drag is equal to gr, where g is the acceleration due to gravity and r is the mixing ratio of the hydrometeors. Hydrometeor loading has a net-negative effect on the atmospheric buoyancy equations. As the hydrometeor falls toward the surface, the surrounding air provides resistance against the acceleration due to gravity, and the air in the vicinity of the hydrometeor becomes denser. The increased weight of the atmosphere can support a present downdraft or even cause a downdraft to occur. Hydrometeor loading can also lead to increased high pressure inside of a mesohigh in a thunderstorm. | 1 | Applied and Interdisciplinary Chemistry |
Muḥammad ibn Umayl al-Tamīmī was a 10th-century Egyptian alchemist of the symbolic-mystical branch. One of his surviving works is Kitāb al-māʿ al-waraqī wa-l-arḍ al-najmiyya (The Book on Silvery Water and Starry Earth). This work is a commentary on his poem, the Risālat al-shams ilā al-hilāl (The Epistle of the Sun to the Crescent Moon) and contains numerous quotations from ancient authors. Ibn Umayl had important influence on medieval Western (Latin) alchemy, where his work is found under different names, mainly as Senior or as Zadith. His "Silvery Water" e.g. was reprinted as "The Chemical Tables of Senior Zadith" in the collection of alchemical texts: Theatrum Chemicum, and commented upon by Pseudo Aquinas in Aurora Consurgens. They both also give his (modified) image of the sage holding a chemical table (see image above). | 1 | Applied and Interdisciplinary Chemistry |
In 2017, FDA granted RT001 orphan drug designation in the treatment of phospholipase 2G6-associated neurodegeneration (PLAN). | 1 | Applied and Interdisciplinary Chemistry |
Organocerium reagents are used almost exclusively for addition reactions in the same vein as organolithium and Grignard reagents.They are highly nucleophilic, allowing additions to imines in the absence of additional Lewis acid catalysts, making them useful for substrates in which typical conditions fail.
Despite this high reactivity, organocerium reagents are almost entirely non-basic, tolerating the presence of free alcohols and amines as well as enolizable α-protons.
They undergo 1,2-addition in reactions with conjugated electrophiles. At the same time, organocerium reagents can be used to synthesize ketones from acyl compounds without over-addition, as seen with organocuprates.
Organocerium reagents have been employed in a number of total syntheses. Shown below is a key coupling step in the total synthesis of roseophilin, a potent antitumor antibiotic. | 0 | Theoretical and Fundamental Chemistry |
The research on transgender reproduction and family planning is limited. A 2020 comparative study of children born to a transgender father and cisgender mother via donor sperm insemination in France showed no significant differences to IVF and naturally conceived children of cisgender parents.
Transgender men can experience challenges in pregnancy and birthing from the cis-normative structure within the medical system, as well as psychological challenges such as renewed gender dysphoria. The effect of continued testosterone therapy during pregnancy and breastfeeding is undetermined. Ethical concerns include reproductive rights, reproductive justice, physician autonomy, and transphobia within the health care setting. | 1 | Applied and Interdisciplinary Chemistry |
Lewis was an instructor of Radiology at the Washington University School of Medicine, Mallinckrodt Institute of Radiology from 2000 to 2002. From 2003 to 2008, he was an assistant professor of radiology at the Washington University School of Medicine, Mallinckrodt Institute of Radiology. He is the Emily Tow Jackson Chair in Oncology, the Vice Chairman for Research (Radiology) and Chief Attending of the Radiochemistry and Imaging Sciences Service at Memorial Sloan Kettering Cancer Center. He also heads a laboratory in the Sloan Kettering Institute's Molecular Pharmacology Program and is a professor at the Gerstner Sloan Kettering Graduate School of Biomedical Sciences.
Lewis holds joint appointments in the Departments of Radiology and the Department of Pharmacology at Weill Cornell Medical School, NY. | 0 | Theoretical and Fundamental Chemistry |
Aromatic nitro compounds are typically synthesized by nitration. Nitration is achieved using a mixture of nitric acid and sulfuric acid, which produce the nitronium ion (), which is the electrophile:
The nitration product produced on the largest scale, by far, is nitrobenzene. Many explosives are produced by nitration including trinitrophenol (picric acid), trinitrotoluene (TNT), and trinitroresorcinol (styphnic acid).
Another but more specialized method for making aryl–NO group starts from halogenated phenols, is the Zinke nitration. | 0 | Theoretical and Fundamental Chemistry |
In a scanning electron microscope the region near the surface can be mapped using an electron beam that is scanned in a grid across the sample. A diffraction pattern can be recorded using electron backscatter diffraction (EBSD), as illustrated in Figure 25, captured with a camera inside the microscope. A depth from a few nanometers to a few microns, depending upon the electron energy used, is penetrated by the electrons, some of which are diffracted backwards and out of the sample. As result of combined inelastic and elastic scattering, typical features in an EBSD image are Kikuchi lines. Since the position of Kikuchi bands is highly sensitive to the crystal orientation, EBSD data can be used to determine the crystal orientation at particular locations of the sample. The data are processed by software yielding two-dimensional orientation maps. As the Kikuchi lines carry information about the interplanar angles and distances and, therefore, about the crystal structure, they can also be used for phase identification or strain analysis. | 0 | Theoretical and Fundamental Chemistry |
Many kinds of diketones are known, some with unusual properties. The simplest is diacetyl , once used as butter-flavoring in popcorn. Acetylacetone (pentane-2,4-dione) is virtually a misnomer (inappropriate name) because this species exists mainly as the monoenol . Its enolate is a common ligand in coordination chemistry. | 0 | Theoretical and Fundamental Chemistry |
COX exists in three conformational states: fully oxidized (pulsed), partially reduced, and fully reduced. Each inhibitor has a high affinity to a different state. In the pulsed state, both the heme a and the Cu nuclear centers are oxidized; this is the conformation of the enzyme that has the highest activity. A two-electron reduction initiates a conformational change that allows oxygen to bind at the active site to the partially-reduced enzyme. Four electrons bind to COX to fully reduce the enzyme. Its fully reduced state, which consists of a reduced Fe at the cytochrome a heme group and a reduced Cu binuclear center, is considered the inactive or resting state of the enzyme.
Cyanide, azide, and carbon monoxide all bind to cytochrome c oxidase, inhibiting the protein from functioning and leading to the chemical asphyxiation of cells. Higher concentrations of molecular oxygen are needed to compensate for increasing inhibitor concentrations, leading to an overall decrease in metabolic activity in the cell in the presence of an inhibitor. Other ligands, such as nitric oxide and hydrogen sulfide, can also inhibit COX by binding to regulatory sites on the enzyme, reducing the rate of cellular respiration.
Cyanide is a non-competitive inhibitor for COX, binding with high affinity to the partially-reduced state of the enzyme and hindering further reduction of the enzyme. In the pulsed state, cyanide binds slowly, but with high affinity. The ligand is posited to electrostatically stabilize both metals at once by positioning itself between them. A high nitric oxide concentration, such as one added exogenously to the enzyme, reverses cyanide inhibition of COX.
Nitric oxide can reversibly bind to either metal ion in the binuclear center to be oxidized to nitrite. NO and CN will compete with oxygen to bind at the site, reducing the rate of cellular respiration. Endogenous NO, however, which is produced at lower levels, augments CN inhibition. Higher levels of NO, which correlate with the existence of more enzyme in the reduced state, lead to a greater inhibition of cyanide. At these basal concentrations, NO inhibition of Complex IV is known to have beneficial effects, such as increasing oxygen levels in blood vessel tissues. The inability of the enzyme to reduce oxygen to water results in a buildup of oxygen, which can diffuse deeper into surrounding tissues. NO inhibition of Complex IV has a larger effect at lower oxygen concentrations, increasing its utility as a vasodilator in tissues of need.
Hydrogen sulfide will bind COX in a noncompetitive fashion at a regulatory site on the enzyme, similar to carbon monoxide. Sulfide has the highest affinity to either the pulsed or partially reduced states of the enzyme, and is capable of partially reducing the enzyme at the heme a center. It is unclear whether endogenous HS levels are sufficient to inhibit the enzyme. There is no interaction between hydrogen sulfide and the fully reduced conformation of COX.
Methanol in methylated spirits is converted into formic acid, which also inhibits the same oxidase system. High levels of ATP can allosterically inhibit cytochrome c oxidase, binding from within the mitochondrial matrix. | 1 | Applied and Interdisciplinary Chemistry |
Although the sequestration of marine carbon is a primary outcome of the biological pump, the recycling of nutrients such as N and P in organic matter plays a comparatively important role in maintaining the processes that facilitate this carbon export without removing nutrients for primary production. One key difference between the lipid pump and biological pump is that the ratios of nutrients such as nitrogen and phosphorus relative to carbon are minimal or zero in lipids, whereas the exported POC in the biological pump retains the standard Redfield ratios found throughout the world's oceans. This is primarily due to zooplankton in their copepodite stages releasing an excessive amount of nitrogen and phosphorus from excretion back into the surface. Thus, the production, transport, and metabolism of lipid carbon during overwintering do not contribute to a net consumption or removal of essential nutrients in the surface ocean, which is unlike many components of the biological pump. This process creates what is known as a "lipid shunt" in the biological pump, as the carbon sequestration of the lipid pump is decoupled from nutrient removal. | 0 | Theoretical and Fundamental Chemistry |
Psychiatrists and doctors commonly prescribe different types of antidepressants to patients. SSRIs, SNRIs, and NDRIs are the most common types of antidepressants. Each has slightly different effects on sexual functioning, but generally, it has been found that antidepressants can delay/decrease orgasms and cause females to have breast enlargement. Dapoxetine in particular takes advantage of the side effect of delayed orgasm and is approved specifically as a medication for the treatment of premature ejaculation rather than as an antidepressant.
The side effects on sexual functioning can impact mental health and quality of life. However, the decrease in depressive symptoms from antidepressants make it worth the sexual side effects for many people. They can be managed by changing the dose, switching drugs, or taking “antidotes”. Maca, a plant that grows in central Peru, aids with sexual dysfunction caused by antidepressant drugs for women. There are specific Maca products that can also increase sexual desire in men. | 1 | Applied and Interdisciplinary Chemistry |
The Institute brings together over 200 technical and scientific staff with a panel of expertise ranging from theoretical chemistry to physics, through modeling, biochemistry, and analytical chemistry. The ISA also has a tip and global instrumentation equipment: NMR spectrometer (1Ghz), hosted by the «Very High Fields NMR European Center» (CRMN Lyon, France ).
The Institute organized its research activities in five areas:
* mass spectrometry
* modeling and applied analysis
* NMR spectroscopy
* separative sciences and surfaces
* (bio)Interfaces, micro / nanosystems.
The research focuses on developing new methods through technological innovation in the analysis of complex systems in all fields, with applications in biomedicine, calculation methods, environment, materials science and structural biology. | 0 | Theoretical and Fundamental Chemistry |
In sediments, oceans, and rivers, distinct trace metal isotope ratios exist due to biological processes such as metal ion uptake and abiotic processes such as adsorption to particulate matter that preferentially remove certain isotopes. The trace metal isotopic composition of a given organism results from a combination of the isotopic compositions of source material (i.e., food and water) and any fractionations imparted during metal ion uptake, translocation and processing inside cells. | 0 | Theoretical and Fundamental Chemistry |
A monosaccharide often switches from the acyclic (open-chain) form to a cyclic form, through a nucleophilic addition reaction between the carbonyl group and one of the hydroxyl groups of the same molecule. The reaction creates a ring of carbon atoms closed by one bridging oxygen atom. The resulting molecule has a hemiacetal or hemiketal group, depending on whether the linear form was an aldose or a ketose. The reaction is easily reversed, yielding the original open-chain form.
In these cyclic forms, the ring usually has five or six atoms. These forms are called furanoses and pyranoses, respectively—by analogy with furan and pyran, the simplest compounds with the same carbon-oxygen ring (although they lack the double bonds of these two molecules). For example, the aldohexose glucose may form a hemiacetal linkage between the aldehyde group on carbon 1 and the hydroxyl on carbon 4, yielding a molecule with a 5-membered ring, called glucofuranose. The same reaction can take place between carbons 1 and 5 to form a molecule with a ring, called glucopyranose. Cyclic forms with a seven-atom ring (the same of oxepane), rarely encountered, are called heptoses.
For many monosaccharides (including glucose), the cyclic forms predominate, in the solid state and in solutions, and therefore the same name commonly is used for the open- and closed-chain isomers. Thus, for example, the term "glucose" may signify glucofuranose, glucopyranose, the open-chain form, or a mixture of the three.
Cyclization creates a new stereogenic center at the carbonyl-bearing carbon. The −OH group that replaces the carbonyls oxygen may end up in two distinct positions relative to the rings midplane. Thus each open-chain monosaccharide yields two cyclic isomers (anomers), denoted by the prefixes α- and β-. The molecule can change between these two forms by a process called mutarotation, that consists in a reversal of the ring-forming reaction followed by another ring formation. | 0 | Theoretical and Fundamental Chemistry |
On 9 July 2014, the European Commission imposed fines of €427,700,000 on Laboratoires Servier and 5 companies which produce generics due to Serviers abuse of their dominant market position, in breach of European Union Competition law. Serviers strategy had included acquiring the principal source of generic production of Perindopril and entering into several pay-for-delay agreements with potential generic competitors. | 0 | Theoretical and Fundamental Chemistry |
Improving PCR based detection of GMOs is a further goal of the European research programme Co-Extra. Research is now underway to develop multiplex PCR methods that can simultaneously detect many different transgenic lines. Another major challenge is the increasing prevalence of transgenic crops with stacked traits. This refers to transgenic cultivars derived from crosses between transgenic parent lines, combining the transgenic traits of both parents. One GM maize variety now awaiting a decision by the European Commission, MON863 x MON810 x NK603, has three stacked traits. It is resistant to an herbicide and to two different kinds of insect pests. Some combined testing methods could give results that would triple the actual GM content of a sample containing this GMO. | 1 | Applied and Interdisciplinary Chemistry |
Systems based on III-V semiconductors, such as InGaP, enable solar-to-hydrogen efficiencies of up to 14%. Challenges include long-term stability and cost. | 0 | Theoretical and Fundamental Chemistry |
Rudd joined the glycobiology institute at the University of Oxford in 1985. At the time, it was difficult for women scientists to secure jobs as academic personnel, and Rudd joined as a glass washer. She learned how to work with glycoproteins and large sugars and eventually completed a doctorate on glycoforms at the Open University in 1995. Rudd moved to the Scripps Research institute, and held a visiting position at the Ben-Gurion University of the Negev. She commercialised her work on liquid chromatography–mass spectrometry (LCMS) with Waters Corporation.
Rudd has worked to miniaturise technologies for glycol analysis. For example, she has used genome-wide association studies (GWAS) to link individual genomes to their serum glycome and individual proteins. She moved to University College Dublin in 2006, where was made head of the Dublin-Oxford glycobiology laboratory research group. She opened the National Institute for Bioprocessing Research and Training (NIBRT), where she developed new processes for protein glycosylation in an attempt to characterise recombinant protein drugs. | 1 | Applied and Interdisciplinary Chemistry |
Although allozymes can detect variations in DNA, it is by an indirect method and not very accurate. DNA-based markers were developed in the 1960s. These markers are much more effective at distinguishing between DNA variants. Today these are the most commonly used markers. DNA-based markers work by surveying nucleotides, which can serve a variety of functions, such as detecting differences in nucleotides or even quantifying the number of mutations. | 1 | Applied and Interdisciplinary Chemistry |
Yulia Sister entered the Department of Chemistry of the University of Kishinev in the fall 1954. While asked by Professor , who interviewed the applicants to the Department, why she has chosen this Department, she explained that thanks to her school teacher she fell in love with chemistry. At the University Yulia was involved in various campus activities, and served as an editor of the faculty newspaper "Chemist". Since her second year at the university she became a member of the student scientific society and was engaged in the research of compounds called heteropolyacids. In 1959 Sister successfully defended her Master's thesis "Precipitation chromatography of heteropolyacids." and graduated with honors from the University of Kishinev.
Upon completion of the studies Sister was assigned to the laboratory of analytical chemistry headed by Professor Yuri Lyalikov. The laboratory was a part of the Institute of Chemistry at the Moldavian branch of the Academy of Sciences of the USSR, which became the Academy of Sciences of Moldova in 1961. Working in this laboratory allowed the young chemist Sister to begin her research with new polarographic methods. In order to carry out analysis of organic compounds by the means of alternating-current (ac) polarography Yulia built with her own hands a polarograph and received the first polarograms. Sister was the first in Moldova (with Y. S. Lyalikov), who applied the methods of ac polarography and second harmonic ac polarography for analyzing organic compounds. Then, together with the physicist Vil Senkevich, they assembled an automatic device, and only later began the serial production of polarographs in the USSR. In the early 1960s Yulia published her first research articles. In 1967 she received her Ph.D. from the Institute of Chemistry of the Moldavian Academy of Sciences.
Through 25 years of research at the Institute of Chemistry Sister dealt with a wide range of topics. Her ecology oriented research included analysis of pesticides in environmental samples, food items and biological mediums. She participated in research and analysis of suspensions and was involved in analyzing new organic compounds. Sister made a substantial contribution to the development of such methods as the second harmonic ac polarography, the difference polarography with magnetic recording, the chromatopolarography. For about 20 years Yulia Sister served as a consultant on the use of the polarographic method in biology at the Department of Human and Animal Physiology of the University of Kishinev.
In 1984 Yulia Sister was invited to work with the Institute of Technology and Development where she soon headed the laboratory of physical and chemical methods. The Institute was affiliated to a research and production association in the Ialoveni (formerly Kutuzov). Sister and her laboratory were using a variety of research methods and among them the high-performance liquid chromatography being at that time a new approach in the laboratories of the country. She also contributed as a board member of Moldavian branch of the Mendeleev Chemical Society and led the program "Young Chemist" in the Moldavian Republic. Many of her students, the former young chemists, became later scientists and managers of respectable companies. | 0 | Theoretical and Fundamental Chemistry |
Conjugating TNP to ATP renders this nucleotide triphosphate fluorescent and colored whilst allowing it to retain its biological activity. TNP-ATP is thus a fluorescent analog of ATP. This conjugation is very useful in providing information about interactions between ATP and an ATP-binding protein because TNP-ATP interacts with proteins and enzymes as a substitute for its parent nucleotide, and has a strong binding affinity for most systems that require ATP.
TNP is excited at a wavelength of 408 and 470 nm, and fluoresces in the 530–560 nm range. This is a very useful range of excitation because it is far from where proteins or nucleotides absorb. When TNP-ATP is in water or other aqueous solutions, this emission is very weak. However, once TNP-ATP binds to a protein, there is a dramatic increase in fluorescent intensity. This property enables researchers to study various proteins’ binding interaction with ATP. Thus, with enhanced fluorescence, it can be seen whether a protein binds to ATP.
When TNP-ATP in water is excited at 410 nm, TNP-ATP shows a single fluorescence maximum at 561 nm. This maximum shifts as the fluid's viscosity changes. For example, in N,N-dimethylformamide, instead of having its maxima at 561 nm as in water, the maxima is instead at 533 nm.
Binding to a protein will also change the wavelength of maximal emission, as well as a change in fluorescent intensity. For example, binding to the chemotaxis protein CheA indicates a severalfold enhancement of fluorescence intensity and a blue-shift in wavelength of the maximal emission.
Using this TNP nucleotide analog has been shown in many instances to be superior to traditional radionucleotide-labelling based techniques. The health concerns and the cost associated with the use of radioactive isotopes makes TNP-ATP an attractive alternative.
The first fluorescent ribose-modified ATP is 2’,3’-O-(2,4,7-trinitrocyclohexadienylidene) adenosine 5’triphosphate (TNP-ATP), and was introduced in 1973 by Hiratsuka and Uchida. TNP-ATP was originally synthesized to investigate the ATP binding site of myosin ATPase. Reports of TNP-ATP’s success in the investigation of this motor protein extended TNP-ATP’s use to other proteins and enzymes. TNP-ATP has now been used as a spectroscopic probe for numerous proteins suspected to have ATP interactions. These include several protein kinases, ATPases, myosin, and other nucleotide binding proteins. Over the past twenty years, there have been hundreds of papers describing TNP-ATP’s use and applications. Many applications involving this fluorescently labeled nucleotide have helped to clarify structure-function relationships of many ATP-requiring proteins and enzymes. There have also been a growing number of papers that display TNP-ATP use as a means of assessing the ATP-binding capacity of various mutant proteins. | 0 | Theoretical and Fundamental Chemistry |
In September 2023, the Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency adopted a positive opinion, recommending the granting of a pediatric use marketing authorization for the medicinal product Aqumeldi, intended for the treatment of heart failure in children from birth to less than 18 years of age. The applicant for this medicinal product is Proveca Pharma Limited. Aqumeldi was approved for medical use in the European Union in November 2023. | 0 | Theoretical and Fundamental Chemistry |
Multiferroics have been used to address fundamental questions in cosmology and particle physics. In the first, the fact that an individual electron is an ideal multiferroic, with any electric dipole moment required by symmetry to adopt the same axis as its magnetic dipole moment, has been exploited to search for the electric dipole moment of the electron. Using the designed multiferroic material , the change in net magnetic moment on switching of the ferroelectric polarisation in an applied electric field was monitored, allowing an upper bound on the possible value of the electron electric dipole moment to be extracted. This quantity is important because it reflects the amount of time-reversal (and hence CP) symmetry breaking in the universe, which imposes severe constraints on theories of elementary particle physics. In a second example, the unusual improper geometric ferroelectric phase transition in the hexagonal manganites has been shown to have symmetry characteristics in common with proposed early universe phase transitions. As a result, the hexagonal manganites can be used to run experiments in the laboratory to test various aspects of early universe physics. In particular, a proposed mechanism for cosmic-string formation has been verified, and aspects of cosmic string evolution are being explored through observation of their multiferroic domain intersection analogues. | 0 | Theoretical and Fundamental Chemistry |
* Discrete dipole approximation codes
* Codes for electromagnetic scattering by cylinders
* Codes for electromagnetic scattering by spheres | 0 | Theoretical and Fundamental Chemistry |
The earliest works that recorded a decrease in pressure drop during turbulent flow were undertaken in the thirties and concerned the transportation of paper pulp. This was, however, not explicitly referred to as a drag reduction phenomenon. Toms was the first to recognize the tremendous reduction in wall shear stress caused by the addition of small amount of linear macromolecules to a turbulent flowing fluid. An extensive bibliography of the first 25 years of drag reduction by polymer additives literature identified over 270 references.
Drag reducers were introduced into the market in the early 1970s by Conoco Inc. (now known as LiquidPower Specialty Products Inc. (LSPI), [http://www.berkshirehathaway.com/subs/sublinks.html a Berkshire Hathaway Company]). Its use has allowed pipeline systems to greatly increase in traditional capacity and extended the life of existing systems. The higher flow rates possible on long pipelines have also increased the potential for surge on older systems not previously designed for high velocities.
Both proprietary (such as Conoco T-83) and non-proprietary (such as poly-isobutylene) drag reduction additives have been evaluated by the U.S. Army Mobility Equipment Research and Development Center for enhancement of military petroleum pipeline systems. | 1 | Applied and Interdisciplinary Chemistry |
A variety of alternative heteroatom oxidation reagents are known, including peroxides (often employed with a transition metal catalyst) and oxaziridines. These reagents do not suffer from the over-oxidation problems and decomposition issues associated with dioxiranes; however, their substrate scope tends to be more limited. Nucleophilic decomposition of dioxiranes to singlet oxygen is a unique problem associated with dioxirane heteroatom oxidations. Although chiral dioxiranes do not provide the same levels of enantioselectivity as other protocols, such as Kagan's sulfoxidation system, complexation to a chiral transition metal complex followed by oxidation affords optically active sulfoxides with good enantioselectivity.
Oxidation of arenes and cumulenes leads initially to epoxides. These substrates are resistant to many epoxidation reagents, including oxaziridines, hydrogen peroxide, and manganese oxo compounds. Organometallic oxidants also react sluggishly with these compounds, with the exception of methyltrioxorhenium. Peracids also react with arenes and cumulenes, but cannot be employed with substrates containing acid-sensitive functionality.
The direct oxidative functionalization of C-H bonds is an ongoing problem in oxidation chemistry. Among metal-free systems, dioxiranes are the best oxidants for the conversion of C-H bonds to alcohols or carbonyls. However, some catalytic transition-metal systems, such as White's palladium-sulfoxide system, are able to oxidize C-H bonds selectively. | 0 | Theoretical and Fundamental Chemistry |
Whenever a water molecule leaves a surface and diffuses into a surrounding gas, it is said to have evaporated. Each individual water molecule which transitions between a more associated (liquid) and a less associated (vapor/gas) state does so through the absorption or release of kinetic energy. The aggregate measurement of this kinetic energy transfer is defined as thermal energy and occurs only when there is differential in the temperature of the water molecules. Liquid water that becomes water vapor takes a parcel of heat with it, in a process called evaporative cooling. The amount of water vapor in the air determines how frequently molecules will return to the surface. When a net evaporation occurs, the body of water will undergo a net cooling directly related to the loss of water.
In the US, the National Weather Service measures the actual rate of evaporation from a standardized "pan" open water surface outdoors, at various locations nationwide. Others do likewise around the world. The US data is collected and compiled into an annual evaporation map. The measurements range from under 30 to over 120 inches per year. Formulas can be used for calculating the rate of evaporation from a water surface such as a swimming pool. In some countries, the evaporation rate far exceeds the precipitation rate.
Evaporative cooling is restricted by atmospheric conditions. Humidity is the amount of water vapor in the air. The vapor content of air is measured with devices known as hygrometers. The measurements are usually expressed as specific humidity or percent relative humidity. The temperatures of the atmosphere and the water surface determine the equilibrium vapor pressure; 100% relative humidity occurs when the partial pressure of water vapor is equal to the equilibrium vapor pressure. This condition is often referred to as complete saturation. Humidity ranges from 0 grams per cubic metre in dry air to 30 grams per cubic metre (0.03 ounce per cubic foot) when the vapor is saturated at 30 °C. | 1 | Applied and Interdisciplinary Chemistry |
Primitive meteorites have been studied using measurements of Δ47. These analyses also assume that the primary isotopic signature of the sample has been lost. In this case, measurements of Δ47 instead provide information on the high-temperature event that isotopically reset the sample. Existing Δ47 analyses on primitive meteorites have been used to infer the duration and temperature of aqueous alteration events, as well as to estimate the isotopic composition of the alteration fluid. | 0 | Theoretical and Fundamental Chemistry |
Current Opinion in Colloid & Interface Science is a bimonthly peer-reviewed scientific journal published by Elsevier. It covers the field of physical chemistry, especially research on colloids and interfaces. The journal was established in 1996 and the editors-in-chiefs are Dganit Danino and Marie Pierre Krafft. According to the Journal Citation Reports, the journal has a 2021 impact factor of 8.209. | 0 | Theoretical and Fundamental Chemistry |
*1988 Japan IBM Science Prize
*1992 Chu-Nichi Culture Award
*2002 Medals with Purple ribbon
*2003 Fellow of the American Association for the Advancement of Science (AAAS)
*2004 Yamada-Koga Prize
*2006 Tetrahedron Prize for Creativity in Organic Chemistry & BioMedicinal Chemistry
*2007 Japan Academy Prize (academics)
*2007 Humboldt Prize
*2011 The Ryoji Noyori Prize
*2012 Fujihara Award
*2017 The Roger Adams Award (American Chemical Society)
*2018 Person of Cultural Merit | 0 | Theoretical and Fundamental Chemistry |
Certain combinations of alloys have become popular as industry standards. Selection of the combination is driven by cost, availability, convenience, melting point, chemical properties, stability, and output. Different types are best suited for different applications. They are usually selected on the basis of the temperature range and sensitivity needed. Thermocouples with low sensitivities (B, R, and S types) have correspondingly lower resolutions. Other selection criteria include the chemical inertness of the thermocouple material and whether it is magnetic or not. Standard thermocouple types are listed below with the positive electrode (assuming ) first, followed by the negative electrode. | 1 | Applied and Interdisciplinary Chemistry |
β-Melanocyte-stimulating hormone (β-MSH) is an endogenous peptide hormone and neuropeptide. It is a melanocortin, specifically, one of the three types of melanocyte-stimulating hormone (MSH), and is produced from proopiomelanocortin (POMC). It is an agonist of the MC, MC, MC, and MC receptors.
β-MSH is artificially generated because it does not exist in humans naturally.
β-MSH is also known to decrease food intake in animals such as rats, chicken due to the effect of proopiomelanocortin (POMC). Research was performed to see the effect β-MSH has on chicks, and it has been found that chicks responded with a decrease in food and water intake when treated with β-MSH. The experiment showed that β-MSH causes anorexigenic effects in chicks. | 1 | Applied and Interdisciplinary Chemistry |
The Bilbao Crystallographic Server also hosts the [https://web.archive.org/web/20111205170131/http://158.227.21.14/incstrdb/ B-IncStrDB: Bilbao Incommensurate Crystal Structures Database], a database for incommensurately modulated and composite structures. | 0 | Theoretical and Fundamental Chemistry |
Clarke was born in Harrow in England. His father was Joseph Thacher Clarke, an archeologist. His older sister was the composer and violist Rebecca Clarke. Hans Clarke attended University College London School, and went on to enter the University as a student of chemistry, where he studied under William Ramsay, J. Norman Collie, and Samuel Smiles. He received a degree (Bachelor of Science) in 1908, and continued performing research at the University directed by Smiles and Stewart. In 1911 he was awarded an 1851 Exhibition Scholarship, which allowed him to study for three semesters in Berlin under Emil Fischer, and one semester with A. W. Stewart at Queen's College, Belfast. On his return he was granted the D.Sc. from London University in 1913. | 0 | Theoretical and Fundamental Chemistry |
The mechanisms of embrittlement are similar to those of metals. Inorganic glass embrittlement can be manifested via static fatigue. Embrittlement in glasses, such as Pyrex, is a function of humidity. Growth rate of cracks vary linearly with humidity, suggesting a first-order kinetic relationship. The static fatigue of Pyrex by this mechanism requires dissolution to be concentrated at the tip of the crack. If the dissolution is uniform along the crack flat surfaces, the crack tip will be blunted. This blunting can actually increase the fracture strength of the material by 100 times.
The embrittlement of SiC/alumina composites serves as an instructive example. The mechanism for this system is primarily the diffusion of oxygen into the material through cracks in the matrix. The oxygen reaches the SiC fibers and produces silicate. Stress concentrates around the newly formed silicate and the fibers strength is degraded. This ultimately leads to fracture at stresses less than the materials typical fracture stress. | 1 | Applied and Interdisciplinary Chemistry |
E. J. Bowen was the eldest of four born to Edmund Riley Bowen and Lilias Bowen (née Kamester) in 1898 in Worcester, England. He attended the Royal Grammar School Worcester.
He won the Brackenbury Scholarship in 1915 to the University of Oxford where he studied chemistry. In 1916, after less than a year of his undergraduate course, he volunteered for training as a gunner officer and served as Second Lieutenant in the Royal Garrison Artillery during World War I. After being demobilised in 1919, he returned to Balliol College. | 0 | Theoretical and Fundamental Chemistry |
In biochemistry, chelatases are enzymes that catalyze the insertion ("metalation") of naturally occurring tetrapyrroles. Many tetrapyrrole-based cofactors exist in nature including hemes, chlorophylls, and vitamin B12. These metallo cofactors are derived by the reaction of metal cations with tetrapyrroles, which are not ligands per se, but the conjugate acids thereof. In the case of ferrochelatases, the reaction that chelatases catalyze is:
:Fe + HP → FeP + 2 H
In the above equation HP represents a sirohydrochlorin or a porphyrin, such as protoporphyrin IX.
Chelatases are required because porphyrins and related macrocyclic ligands are extremely slow to metalate, despite favorable thermodynamics. These low rates are attributed to the tight fit of the metal into the rigid 18- or 17-membered tetrapyrrole macrocycle. Several families of chelatase are known including cobalt chelatase, magnesium chelatase, and ferrochelatase. Nickel insertion into a sirohydrochlorin also requires a chelatase as part of the biosynthesis of cofactor F430. Apparently that chelatase is identical to the cobalt chelatase. | 0 | Theoretical and Fundamental Chemistry |
Pdr1p and Pdr3p also interact with other transcription factors and their associated networks such as Yap1p, which controls oxidative stress response, and Rpn4p, which regulates proteasome activities, depending on the kinds of toxins cells face. It is known that Pdr1p induces the expression of Rpn4p. | 1 | Applied and Interdisciplinary Chemistry |
In nanogap cells the high electric field can distribute uniformly across the entire gap (see section "Electric field distribution"). This is different from ion transport in the macrosystem: now newly generated OH ions can immediately migrate from cathode to anode. In the case where the two electrodes are close enough, the mass transport rate can be even larger than the electron-transfer rate. This results in OH ions clustering for electron-transfer at the anode, rather than accumulating at the cathode. In this way the entire reaction can keep going and not self-limit.
Notice that for pure water electrolysis in nanogap cells, the net OH ion accumulation near the anode not only increases the local reactant concentration but also decreases the overpotential requirement (as in the Frumkin effect). According to Butler–Volmer equation, such ion accumulation increases the electrolysis current, i.e. the water splitting throughput and efficiency.
Thus even pure water can be efficiently electrolyzed, when the electrode gap is small enough. | 0 | Theoretical and Fundamental Chemistry |
The fluids associated with the human body include air, oxygen, carbon dioxide, water, solvents, solutions, suspensions, serum, lymph, and blood. The major body fluid which acts as the lifeline of the living organisms is "Blood". Blood is an extremely complex biological fluid. It consists of blood cells suspended in plasma and other different types of cells which include white blood cells, platelets etc. The blood flow in arteries and veins are closely linked to the blood vessel properties.
Carrying the oxygen and nutrients to various tissues and organs of our body, delivering carbon dioxide to the lungs and accepting oxygen, bringing the metabolic by products to the kidneys, regulating the body's defence mechanism, that is, the immune system and facilitating an effective heat and mass transfer across the body are some of the major functions which blood performs in the human body.
Blood consists of the red blood cells or erythrocytes, white blood cells or leukocytes, and platelets or thrombocytes. The cells which are involved primarily in the transport of oxygen and carbon dioxide are known as Erythrocytes. The cells which are involved primarily in phagocytosis (the process of destruction of unknown particulate matter) and immune responses are known as Leukocytes; thrombocytes are the components of blood which are involved in blood clotting. In addition to these 55 to 60 percent of blood by volume consists of plasma. Plasma is the transparent, amber-colored liquid in which the cellular components of blood are suspended. Plasma contains constituents such as proteins, electrolytes, hormones, and nutrients. The serum is blood plasma from which clotting factors have been removed. Blood accounts for 6 to 8 percent of body weight in normal, healthy humans. The density of blood is slightly greater than the density of water at approximately 1060 kg/m3. The increased density comes from the increased density of a red blood cell compared with the density of water or plasma.
Rheology is the study of the deformation and flow of matter. Blood Rheology is the study of blood, especially the properties associated with the deformation and flow of blood. Blood is a non-Newtonian fluid. However, often the non-Newtonian effect is very small due to various reasons. Thus, it is important to know about the blood rheology.
One of the characteristics of blood that affects the work required to cause the blood to flow through the arteries is the viscosity of blood. The viscosity of blood is in the range of 3 to 6 cP, or 0.003 to 0.006 Ns/m2. Blood is a non-Newtonian fluid, which means that the viscosity of blood is not a constant with respect to the rate of shearing strain. In addition to the rate of shearing strain, the viscosity of blood is also dependent on temperature and on the volume percentage of blood that consists of red blood cells. If blood is made stationary for several seconds then clotting begins in the blood, as a result of which the viscosity of the blood increases. When the stationary state is disturbed with increasing shear rate, the clot formation is destroyed and the viscosity decreases. Moreover, the orientation of red blood cells present in the blood also affects the viscosity of blood. Thus, we can say that blood is a shear thinning fluid, i.e., viscosity decreases with increase in shear rate. Beyond a shear rate of about 100s^-1, the viscosity is nearly constant and the blood behaves like a Newtonian fluid. Blood is a viscoelastic material, i.e., viscous and elastic because the effective viscosity of blood not only depends on the shear rate but also on the history of shear rate. It is also important to note that the normal blood flows much more easily compared to rigid particles, for the same particle volume fraction. This is due to the fact that red blood cells can accommodate by deforming in order to pass by one another. | 1 | Applied and Interdisciplinary Chemistry |
One of the most time-consuming aspects of endotoxin testing using LAL is pretreating samples to overcome assay inhibition that may interfere with the LAL test such that the recovery of endotoxin is affected. If the product being tested causes the endotoxin recovery to be less than expected, the product is inhibitory to the LAL test. Products which cause higher than expected values are enhancing. Overcoming the inhibition and enhancement properties of a product is required by the FDA as part of the validation of the LAL test for use in the final release testing of injectables and medical devices. Proper endotoxin recovery must be proven before LAL can be used to release product. | 0 | Theoretical and Fundamental Chemistry |
The simplest DNA end of a double stranded molecule is called a blunt end. Blunt ends are also known as non-cohesive ends. In a blunt-ended molecule, both strands terminate in a base pair. Blunt ends are not always desired in biotechnology since when using a DNA ligase to join two molecules into one, the yield is significantly lower with blunt ends. When performing subcloning, it also has the disadvantage of potentially inserting the insert DNA in the opposite orientation desired. On the other hand, blunt ends are always compatible with each other. Here is an example of a small piece of blunt-ended DNA: | 1 | Applied and Interdisciplinary Chemistry |
Triazenes are organic compounds that contain the functional group R−N=N−NRR, where the R are each any of various types of substituent groups. Some anti-cancer medications and dyes are triazenes. Formally, the triazenes are related to the unstable chemical triazene, HN−N=NH. | 0 | Theoretical and Fundamental Chemistry |
Iron ores are overwhelmingly derived from ancient sediments known as banded iron formations (BIFs). These sediments are composed of iron oxide minerals deposited on the sea floor. Particular environmental conditions are needed to transport enough iron in sea water to form these deposits, such as acidic and oxygen-poor atmospheres within the Proterozoic Era.
Often, more recent weathering is required to convert the usual magnetite minerals into more easily processed hematite. Some iron deposits within the Pilbara of Western Australia are placer deposits, formed by accumulation of hematite gravels called pisolites which form channel-iron deposits. These are preferred because they are cheap to mine. | 0 | Theoretical and Fundamental Chemistry |
It may cause irritation. Its toxicological properties have not been fully investigated. Harmful if swallowed, Acute Toxicity. Only Hazardous when percent values are above 10%. | 0 | Theoretical and Fundamental Chemistry |
As all other fluorescent proteins, Kaede can be the regional optical markers for gene expression and protein labeling for the study of cell behaviors.
One of the most useful applications is the visualization of neurons. Delineation of an individual neuron is difficult due to the long and thin processes which entangle with other neurons. Even when cultured neurons are labeled with fluorescent proteins, they are still difficult to identify individually because of the dense package.
In the past, such visualization could be done conventionally by filling neurons with Lucifer yellow or sulforhodamine, which is a laborious technique.[1] After the discovery of Kaede protein, it was found to be useful in delineating individual neurons. The neurons are transfected by Kaede protein cDNA, and are UV irradiated. The red, photoconverted Kaede protein has free diffusibility in the cell except for the nucleus, and spreads over the entire cell including dendrites and axon. This technique help disentangle the complex networks established in a dense culture. Besides, by labeling neurons with different colors by UV irradiating with different duration times, contact sites between the red and green neurons of interest are allowed to be visualized.
The ability of visualization of individual cells is also a powerful tool to identify the precise morphology and migratory behaviors of individual cells within living cortical slices. By Kaede protein, a particular pair of daughter cells in neighboring Kaede-positive cells in the ventricular zone of mouse brain slices can be followed. The cell-cell borders of daughter cells are visualized and the position and distance between two or more cells can be described.
As the change in the fluorescent colour is induced by UV light, marking of cells and subcellular structures is efficient even when only a partial photoconversion is induced. | 1 | Applied and Interdisciplinary Chemistry |
Hematochrome is a yellow, orange, or (most commonly) red biological pigment present in some green algae, especially when exposed to intense light. It is a name used mainly in older literature. Hematochrome is a mixture of carotenoid pigments and their derivates. | 1 | Applied and Interdisciplinary Chemistry |
Being a partial differential equation, the Fokker–Planck equation can be solved analytically only in special cases. A formal analogy of the Fokker–Planck equation with the Schrödinger equation allows the use of advanced operator techniques known from quantum mechanics for its solution in a number of cases. Furthermore, in the case of overdamped dynamics when the Fokker–Planck equation contains second partial derivatives with respect to all spatial variables, the equation can be written in the form of a master equation that can easily be solved numerically.
In many applications, one is only interested in the steady-state probability distribution , which can be found from .
The computation of mean first passage times and splitting probabilities can be reduced to the solution of an ordinary differential equation which is intimately related to the Fokker–Planck equation. | 1 | Applied and Interdisciplinary Chemistry |
Rayleigh was an Anglican. Though he did not write about the relationship of science and religion, he retained a personal interest in spiritual matters. When his scientific papers were to be published in a collection by the Cambridge University Press, Strutt wanted to include a quotation from the Bible, but he was discouraged from doing so, as he later reported:
Still, he had his wish and the quotation was printed in the five-volume collection of scientific papers. In a letter to a family member, he wrote about his rejection of materialism and spoke of Jesus Christ as a moral teacher:
He held an interest in parapsychology and was an early member of the Society for Psychical Research (SPR). He was not convinced of spiritualism but remained open to the possibility of supernatural phenomena. Rayleigh was the president of the SPR in 1919. He gave a presidential address in the year of his death but did not come to any definite conclusions. | 1 | Applied and Interdisciplinary Chemistry |
Base-promoted epoxide isomerization is the conversion of alkyl epoxides to ring-opened products through the action of strong base. Isomerizations of this type are most often used to synthesize allylic alcohols, although other products are possible. | 0 | Theoretical and Fundamental Chemistry |
A racemate is optically inactive (achiral), meaning that such materials do not rotate the polarization of plane-polarized light. Although the two enantiomers rotate plane-polarized light in opposite directions, the rotations cancel each other out because they are present in equal amounts of negative (-) counterclockwise (levorotatory) and positive (+) clockwise (dextrorotatory) enantiomers.
In contrast to the two pure enantiomers, which have identical physical properties except for the direction of rotation of plane-polarized light, a racemate sometimes has different properties from either of the pure enantiomers. Different melting points are most common, but different solubilities and boiling points are also possible.
Pharmaceuticals may be available as a racemate or as the pure enantiomer, which might have different potencies. Because biological systems have many chiral asymmetries, pure enantiomers frequently have very different biological effects; examples include glucose and methamphetamine. | 0 | Theoretical and Fundamental Chemistry |
Deriving the Gibbs–Duhem equation from basic thermodynamic state equations is straightforward. Equating any thermodynamic potential definition with its Euler relation expression yields:
Differentiating, and using the second law:
yields:
Which is the Gibbs–Duhem relation. The Gibbs–Duhem is a relationship among the intensive parameters of the system. It follows that for a simple system with components, there will be independent parameters, or degrees of freedom. For example, a simple system with a single component will have two degrees of freedom, and may be specified by only two parameters, such as pressure and volume for example. The law is named after Josiah Willard Gibbs and Pierre Duhem. | 0 | Theoretical and Fundamental Chemistry |
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