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Photochemistry Thus, triplet states generally have longer lifetimes than singlet states. These transitions are usually summarized in a state energy diagram or Jablonski diagram, the paradigm of molecular photochemistry. These excited species, either S or T, have a half empty low-energy orbital, and are consequently more oxidizing than the ground state. But at the same time, they have an electron in a high energy orbital, and are thus more reducing. In general, excited species are prone to participate in electron transfer processes. Photochemical reactions require a light source that emits wavelengths corresponding to an electronic transition in the reactant. In the early experiments (and in everyday life), sunlight was the light source, although it is polychromatic. Mercury-vapor lamps are more common in the laboratory. Low pressure mercury vapor lamps mainly emit at 254 nm. For polychromatic sources, wavelength ranges can be selected using filters. Alternatively, laser beams are usually monochromatic (although two or more wavelengths can be obtained using nonlinear optics) and LEDs have a relatively narrowband that can be efficiently used, as well as Rayonet lamps, to get approximately monochromatic beams. The emitted light must of course reach the targeted functional group without being blocked by the reactor, medium, or other functional groups present. For many applications, quartz is used for the reactors as well as to contain the lamp. Pyrex absorbs at wavelengths shorter than 275 nm | https://en.wikipedia.org/wiki?curid=363430 |
Photochemistry The solvent is an important experimental parameter. Solvents are potential reactants and for this reason, chlorinated solvents are avoided because the C-Cl bond can lead to chlorination of the substrate. Strongly absorbing solvents prevent photons from reaching the substrate. Hydrocarbon solvents absorb only at short wavelengths and are thus preferred for photochemical experiments requiring high energy photons. Solvents containing unsaturation absorb at longer wavelengths and can usefully filter out short wavelengths. For example, cyclohexane and acetone "cut off" (absorb strongly) at wavelengths shorter than 215 and 330 nm, respectively. Continuous flow photochemistry offers multiple advantages over batch photochemistry. Photochemical reactions are driven by the number of photons that are able to activate molecules causing the desired reaction. The large surface area to volume ratio of a microreactor maximizes the illumination, and at the same time allows for efficient cooling, which decreases the thermal side products. In the case of photochemical reactions, light provides the activation energy. Simplistically, light is one mechanism for providing the activation energy required for many reactions. If laser light is employed, it is possible to selectively excite a molecule so as to produce a desired electronic and vibrational state. Equally, the emission from a particular state may be selectively monitored, providing a measure of the population of that state | https://en.wikipedia.org/wiki?curid=363430 |
Photochemistry If the chemical system is at low pressure, this enables scientists to observe the energy distribution of the products of a chemical reaction before the differences in energy have been smeared out and averaged by repeated collisions. The absorption of a photon of light by a reactant molecule may also permit a reaction to occur not just by bringing the molecule to the necessary activation energy, but also by changing the symmetry of the molecule's electronic configuration, enabling an otherwise inaccessible reaction path, as described by the Woodward–Hoffmann selection rules. A 2+2 cycloaddition reaction is one example of a pericyclic reaction that can be analyzed using these rules or by the related frontier molecular orbital theory. Some photochemical reactions are several orders of magnitude faster than thermal reactions; reactions as fast as 10 seconds and associated processes as fast as 10 seconds are often observed. The photon can be absorbed directly by the reactant or by a photosensitizer, which absorbs the photon and transfers the energy to the reactant. The opposite process is called quenching when a photoexited state is deactivated by a chemical reagent. Most photochemical transformations occur through a series of simple steps known as primary photochemical processes. One common example of these processes is the excited state proton transfer. Examples of photochemical organic reactions are electrocyclic reactions, radical reactions, photoisomerization and Norrish reactions | https://en.wikipedia.org/wiki?curid=363430 |
Photochemistry Alkenes undergo many important reactions that proceed via a photon-induced π to π* transition. The first electronic excited state of an alkene lack the π-bond, so that rotation about the C-C bond is rapid and the molecule engages in reactions not observed thermally. These reactions include cis-trans isomerization, cycloaddition to other (ground state) alkene to give cyclobutane derivatives. The cis-trans isomerization of a (poly)alkene is involved in retinal, a component of the machinery of vision. The dimerization of alkenes is relevant to the photodamage of DNA, where thymine dimers are observed upon illuminating DNA to UV radiation. Such dimers interfere with transcription. The beneficial effects of sunlight are associated with the photochemically induced retro-cyclization (decyclization) reaction of ergosterol to give vitamin D. In the DeMayo reaction, an alkene reacts with a 1,3-diketone reacts via its enol to yield a 1,5-diketone. Still another common photochemical reaction is Zimmerman's Di-pi-methane rearrangement. In an industrial application, about 100,000 tonnes of benzyl chloride are prepared annually by the gas-phase photochemical reaction of toluene with chlorine. The light is absorbed by chlorine molecule, the low energy of this transition being indicated by the yellowish color of the gas | https://en.wikipedia.org/wiki?curid=363430 |
Photochemistry The photon induces homolysis of the Cl-Cl bond, and the resulting chlorine radical converts toluene to the benzyl radical: Mercaptans can be produced by photochemical addition of hydrogen sulfide (HS) to alpha olefins. Coordination complexes and organometallic compounds are also photoreactive. These reactions can entail cis-trans isomerization. More commonly photoreactions result in dissociation of ligands, since the photon excites an electron on the metal to an orbital that is antibonding with respect to the ligands. Thus, metal carbonyls that resist thermal substitution undergo decarbonylation upon irradiation with UV light. UV-irradiation of a THF solution of molybdenum hexacarbonyl gives the THF complex, which is synthetically useful: In a related reaction, photolysis of iron pentacarbonyl affords diiron nonacarbonyl (see figure): Select photoreactive coordination complexes can undergo oxidation-reduction processes via single electron transfer. This electron transfer can occur within the inner or outer coordination sphere of the metal. Although bleaching has long been practiced, the first photochemical reaction was described by Trommsdorff in 1834. He observed that crystals of the compound α-santonin when exposed to sunlight turned yellow and burst. In a 2007 study the reaction was described as a succession of three steps taking place within a single crystal | https://en.wikipedia.org/wiki?curid=363430 |
Photochemistry The first step is a rearrangement reaction to a cyclopentadienone intermediate 2, the second one a dimerization in a Diels-Alder reaction (3) and the third one an intramolecular [2+2]cycloaddition (4). The bursting effect is attributed to a large change in crystal volume on dimerization. | https://en.wikipedia.org/wiki?curid=363430 |
Sabir Yunusov Sabir Yunusovich Yunusov (; 18 March 1909 in Tashkent – 29 November 1995 in Tashkent) was a Soviet-Uzbek chemist, known for his research in alkaloid chemistry. In 1971 he was awarded the D.I. Mendeleev Medal for doing so. He founded the Institute of the Chemistry of Plant Substances under the Academy of Sciences of the Uzbek SSR (of Uzbekistan since 1991) in 1956. He was a corresponding member of the Academy of Sciences of the USSR (of Russia since 1991) from 1958 until his death. He died and was buried in Tashkent, Uzbekistan. | https://en.wikipedia.org/wiki?curid=364059 |
Distribution function (physics) In molecular kinetic theory in physics, a particle's distribution function is a function of seven variables, formula_1, which gives the number of particles per unit volume in single-particle phase space. It is the number of particles per unit volume having approximately the velocity formula_2 near the position formula_3 and time formula_4. The usual normalization of the distribution function is where, "N" is the total number of particles, and "n" is the number density of particles – the number of particles per unit volume, or the density divided by the mass of individual particles. A distribution function may be specialised with respect to a particular set of dimensions. E.g. take the quantum mechanical six-dimensional phase space, formula_7 and multiply by the total space volume, to give the momentum distribution, i.e. the number of particles in the momentum phase space having approximately the momentum formula_8. Particle distribution functions are often used in plasma physics to describe wave–particle interactions and velocity-space instabilities. Distribution functions are also used in fluid mechanics, statistical mechanics and nuclear physics. The basic distribution function uses the Boltzmann constant formula_9 and temperature formula_10 with the number density to modify the normal distribution: Related distribution functions may allow bulk fluid flow, in which case the velocity origin is shifted, so that the exponent's numerator is formula_12, where formula_13 is the bulk velocity of the fluid | https://en.wikipedia.org/wiki?curid=365876 |
Distribution function (physics) Distribution functions may also feature non-isotropic temperatures, in which each term in the exponent is divided by a different temperature. Plasma theories such as magnetohydrodynamics may assume the particles to be in thermodynamic equilibrium. In this case, the distribution function is "Maxwellian". This distribution function allows fluid flow and different temperatures in the directions parallel to, and perpendicular to, the local magnetic field. More complex distribution functions may also be used, since plasmas are rarely in thermal equilibrium. The mathematical analogue of a distribution is a measure; the time evolution of a measure on a phase space is the topic of study in dynamical systems. | https://en.wikipedia.org/wiki?curid=365876 |
Leaflet (botany) A leaflet (occasionally called foliole) in botany is a leaf-like part of a compound leaf. Though it resembles an entire leaf, a leaflet is not borne on a main plant stem or branch, as a leaf is, but rather on a petiole or a branch of the leaf. Compound leaves are common in many plant families and they differ widely in morphology. The two main classes of compound leaf morphology are palmate and pinnate. For example, a "hemp" plant has palmate compound leaves, whereas some species of "Acacia" have pinnate leaves. The ultimate free division (or leaflet) of a compound leaf, or a pinnate subdivision of a multipinnate leaf is called a pinnule or pinnula. | https://en.wikipedia.org/wiki?curid=368910 |
Guide star In astronomy, a guide star is a reference star used to accurately maintain the tracking by a telescope of a heavenly body, whose motion across the sky is primarily due to the rotation of the Earth. Accurate telescope pointing and tracking is critical for obtaining good astronomical images and astrophotographs. However, because the Earth rotates, the sky appears to be in a constant state of motion relative to the Earth. Although this movement appears to be relatively slow when viewed with the naked eye, with the high magnification and consequently smaller field of view provided by even a small telescope this motion becomes apparent on timescales of the order of seconds. Though space telescopes are not mounted on a spinning planet, they still use guide stars including those listed in the HST Guide Star Catalog. Computer-controlled electric motors are commonly employed to allow the telescope to move in sync with the apparent motion of the sky, according to a pre-computed pointing model. However, there is usually a significant non-zero error associated with the model, which is an approximation to the true motion of the sky. Most modern professional telescopes use a guide star. An autoguider is pointed to a sufficiently luminous star that lies near the object being observed and, if the pointing begins to drift, the error can be detected and the movement corrected | https://en.wikipedia.org/wiki?curid=369087 |
Guide star This is most accurate when the corrections are applied by a computer, but amateur telescopes often have manual correction (requiring the observer to continuously follow the star by eye for the exposure period, which may be a significant length of time). Guide stars are also employed in adaptive optics. In this application, the star is not used to correct for the rotation of the Earth, but to correct for turbulence in the Earth's atmosphere. By measuring the observed motion of the guide star, and making minute distortions to the primary mirror, the telescope can produce images with much greater sharpness than is possible without adaptive optics. However, only about 1 percent of the night sky is close enough to a natural guide star to use adaptive optics, so various methods to create artificial laser guide stars have been developed, including the sodium laser system developed by the Lawrence Livermore National Laboratory and used by the University of California's Lick and Keck observatories. | https://en.wikipedia.org/wiki?curid=369087 |
Harish-Chandra FRS (11 October 1923 – 16 October 1983) was an Indian American mathematician and physicist who did fundamental work in representation theory, especially harmonic analysis on semisimple Lie groups. was born in Kanpur. He was educated at B.N.S.D. College, Kanpur and at the University of Allahabad. After receiving his master's degree in Physics in 1943, he moved to the Indian Institute of Science, Bangalore for further studies in theoretical physics and worked with Homi J. Bhabha. In 1945, he moved to University of Cambridge, and worked as a research student under Paul Dirac. While at Cambridge, he attended lectures by Wolfgang Pauli, and during one of them pointed out a mistake in Pauli's work. The two were to become lifelong friends. During this time he became increasingly interested in mathematics. At Cambridge he obtained his PhD in 1947. He was a member of the National Academy of Sciences and a Fellow of the Royal Society. He was the recipient of the Cole Prize of the American Mathematical Society, in 1954. The Indian National Science Academy honoured him with the Srinivasa Ramanujan Medal in 1974. In 1981, he received an honorary degree from Yale University. The mathematics department of V.S.S.D. College, Kanpur celebrates his birthday every year in different forms, which includes lectures from students and professors from various colleges, institutes and students' visit to Research Institute | https://en.wikipedia.org/wiki?curid=373190 |
Harish-Chandra The Indian Government named the Research Institute, an institute dedicated to Theoretical Physics and Mathematics, after him. Robert Langlands wrote in a biographical article of Harish-Chandra: He was also a recipient of the Padma Bhushan in 1977. | https://en.wikipedia.org/wiki?curid=373190 |
Biogen Inc. is an American multinational biotechnology company based in Cambridge, Massachusetts, specializing in the discovery, development, and delivery of therapies for the treatment of neurological diseases to patients worldwide. was founded in 1978 in Geneva by several prominent biologists, including Kenneth Murray of the University of Edinburgh, Phillip Allen Sharp of the Massachusetts Institute of Technology, Walter Gilbert of Harvard (who served as CEO during the start-up phase), Heinz Schaller, University of Heidelberg and Charles Weissmann, University of Zurich (who contributed the first product interferon alpha). Gilbert and Sharp were subsequently honored with Nobel Prizes: Gilbert was recognized in 1980 with the Nobel Prize in Chemistry for his work in understanding DNA sequencing, while Sharp received the Nobel Prize in Physiology or Medicine in 1993 for his discovery of split genes. In 2003, merged with San Diego, California-based IDEC Pharmaceuticals (formed in 1985 by Ivor Royston, Howard Birndorf and others) and adopted the name Idec. After the merger, Idec became the 3rd largest Biotechnology company in the world. Following shifts in research core areas, the company has since shortened its name, reverting to simply Biogen. stock is a component of several stock indices such as the S&P 100, S&P 500, S&P 1500, and NASDAQ-100 and the company is listed on the NASDAQ stock exchange under the ticker symbol, BIIB | https://en.wikipedia.org/wiki?curid=380532 |
Biogen In May 2006, the company announced it would acquire cancer specialist, Conforma Therapeutics for $250 million. Later in the same month, the company announced its intention to acquire Fumapharm AG, consolidating ownership of Fumaderm and BG-12, an oral fumarate, which is being studied for the treatment of multiple sclerosis and psoriasis. In January 2007, the company announced it would acquire Syntonix Pharmaceuticals for up to $120 million, gaining Syntonix's lead product for hemophilia B as well as the technology for developing inhalable treatments. In February 2013, Bloomberg broke the news that was planning to pay Elan $3.25 billion for the full rights to Tysabri, used to treat multiple sclerosis. In January 2015, the company announced that it would acquire Convergence Pharmaceuticals for up to $675 million, with the acquisition aiming to accelerate the development of Convergence's pipeline, in particular CNV1014802 – a Phase II small molecule sodium channel blocking candidate. In October 2015, the company announced that it would lay off 11% of its workforce, effective immediately. In March 2019, announced it would acquire Nightstar Therapeutics for $25.50 per share ($800 million in total). Nightstar focus on adeno-associated virus based gene-therapies for inherited retinal disorders. With a setback in their Alzheimer's drug research, in March 2019 Biogen's shares fell sharply. It ended the trial of its drug aducanumab, which it was making along with Eisai | https://en.wikipedia.org/wiki?curid=380532 |
Biogen In October 2019, however, they announced that they would pursue FDA approval for aducanumab together with Eisai. In February 2020, and Sangamo Therapeutics announced a global licensing deal to develop compounds for neuromuscular and neurological diseases. In May 2016, the company announced that it would spin off its hemophilia drug business (Eloctate and Alprolix) into a public company. In August, the company announced that the spun off company would be called Bioverativ, in order to show heritage with Biogen. The company would trade on the NASDAQ exchange under the ticker symbol BIVV and would look to be spun off in early 2017. The following is an illustration of the company's major mergers and acquisitions and historical predecessors (this is not a comprehensive list): For the fiscal year 2017, reported earnings of US$2.539 billion, with an annual revenue of US$12.274 billion, an increase of 7.2% over the previous fiscal cycle. Biogen's shares traded at over $289 per share, and its market capitalization was valued at over US$63 billion in November 2018. The company ranked 245 on the 2018 Fortune 500 list of the largest United States corporations by revenue. has focused its R&D efforts on the discovery and development of treatments for patients with high unmet medical needs in the areas of neurology, hematology and immunology | https://en.wikipedia.org/wiki?curid=380532 |
Biogen Investigational MS medicines: has several candidates in Phase 1 and 2 clinical trials in neurodegenerative and immunological diseases including MS, neuropathic pain, spinal muscular atrophy and lupus nephritis: also has several development agreements in place with Ionis Pharmaceuticals to collaborate to leverage antisense technology in advancing the treatment of neurological disorders. In February 2012, formalized a joint venture with Samsung, creating Samsung Bioepis. This joint venture brings Biogen's expertise and capabilities in protein engineering, cell line development, and recombinant biologics manufacturing to position the joint venture so can participate in the emerging market for biosimilars. In early 2014, entered into an agreement with Eisai, Inc., to jointly develop and commercialize two of their candidates for Alzheimer's disease, which have the potential to reduce Aβ plaques that form in the brains of patients, as well as to slow the formation of new plaques, potentially improving symptoms and suppressing disease progression. also has since 2015 an agreement with AGTC for the development of gene therapy for ophthalmologic diseases such as X-linked retinoschisis (XLRS) and X-linked Retinitis pigmentosa (XLRP), and up to three other genetic diseases. To this aim, paid AGTC $124 million, including an equity investment of $30 million, and up to 1,1 billion in future milestones | https://en.wikipedia.org/wiki?curid=380532 |
Biogen In March 2019, halted Phase 3 trials of Alzheimer's disease drug Aducanumab after "an independent group's analysis show[ed] that the trials were unlikely to 'meet their primary endpoint.'" However, in October 2019 they reversed their plans and said that they would be pursuing US FDA approval for Aducanumab. The reversal came after said a new analysis of a larger patient pool showed promising results. | https://en.wikipedia.org/wiki?curid=380532 |
Inverse scattering problem In mathematics and physics, the inverse scattering problem is the problem of determining characteristics of an object, based on data of how it scatters incoming radiation or particles. It is the inverse problem to the direct scattering problem, which is to determine how radiation or particles are scattered based on the properties of the scatterer. Soliton equations are a class of partial differential equations which can be studied and solved by a method called the inverse scattering transform, which reduces the nonlinear PDEs to a linear inverse scattering problem. The nonlinear Schrödinger equation, the Korteweg–de Vries equation and the KP equation are examples of soliton equations. In one space dimension the inverse scattering problem is equivalent to a Riemann-Hilbert problem. Since its early statement for radiolocation, many applications have been found for inverse scattering techniques, including echolocation, geophysical survey, nondestructive testing, medical imaging, quantum field theory. https://www.springer.com/mathematics/dynamical+systems/book/978-1-4614-4941-6 | https://en.wikipedia.org/wiki?curid=385661 |
Geosphere There are several conflicting definitions for geosphere. The geosphere may be taken as the collective name for the lithosphere, the hydrosphere, the cryosphere, and the atmosphere. The different collectives of the geosphere are able to exchange different mass and/or energy fluxes (the measurable amount of change). The exchange of these fluxes affects the balance of the different spheres of the geosphere. An example is how the soil acts as a part of the biosphere, while also acting as a source of flux exchange. In Aristotelian physics, the term was applied to four spherical "natural places", concentrically nested around the center of the Earth, as described in the lectures "Physica" and "Meteorologica". They were believed to explain the motions of the four "terrestrial elements:" "Earth", "Water", "Air", and "Fire". In modern texts and in Earth system science, geosphere refers to the solid parts of the Earth; it is used along with atmosphere, hydrosphere, and biosphere to describe the systems of the Earth (the interaction of these systems with the magnetosphere is sometimes listed). In that context, sometimes the term lithosphere is used instead of geosphere or solid Earth. The lithosphere, however, only refers to the uppermost layers of the solid Earth (oceanic and continental crustal rocks and uppermost mantle) | https://en.wikipedia.org/wiki?curid=387243 |
Geosphere Since space exploration began, it has been observed that the extent of the ionosphere or plasmasphere is highly variable, and often much larger than previously appreciated, at times extending to the boundaries of the Earth's magnetosphere or geomagnetosphere. This highly variable outer boundary of "geogenic" matter has been referred to as the "geopause", to suggest the relative scarcity of such matter beyond it, where the solar wind dominates. | https://en.wikipedia.org/wiki?curid=387243 |
Vitaly Zholobov Vitaly Mikhaylovich Zholobov (; born 18 June 1937) is a retired Soviet cosmonaut who flew on Soyuz 21 space flight as the flight engineer. Zholobov joined the space programme from the Soviet Air Force where he held the rank of Colonel-engineer. His only trip to space involved a two-month stay on the Salyut 5 space station (Soyuz 21 mission). The flight was scheduled to last for 60 days but lasted for only 49. The reason for the cancellation was the detection of a noxious odor on board. Vitaly Zsholobow reported to the Mission Control Center that the smell was similar to that of a propellant which was known to be toxic. The Control Center decided to abort the mission to avoid exposing the crew to further risk and because the research and technology programs were already successfully finished. He was in orbit from 6 June 1976 to 24 August 1976. Although he never flew again, Zholobov stayed in the space programme until 1981 when he resigned to become director of a geological science research group. | https://en.wikipedia.org/wiki?curid=387999 |
Subvariety A subvariety (Latin: subvarietas) in botanical nomenclature is a taxonomic rank. They are rarely used to classify organisms. is ranked: is an infraspecific taxon. Its name consists of three parts: To indicate the subvariety rank, the abbreviation "subvar." is put before the infraspecific epithet. | https://en.wikipedia.org/wiki?curid=393574 |
Orphan drug An orphan drug is a pharmaceutical agent developed to treat medical conditions which, because they are so rare, would not be profitable to produce without government assistance. The conditions are referred to as orphan diseases. The assignment of orphan status to a disease and to drugs developed to treat it is a matter of public policy in many countries and has yielded medical breakthroughs that might not otherwise have been achieved, due to the economics of drug research and development. In the U.S. and the EU, it is easier to gain marketing approval for an orphan drug. There may be other financial incentives, such as an extended period of exclusivity, during which the producer has sole rights to market the drug. All are intended to encourage development of drugs which would otherwise lack sufficient profit motive to attract corporate research budgets and personnel. According to the US Food and Drug Administration (FDA), an orphan drug is defined as one "intended for the treatment, prevention or diagnosis of a rare disease or condition, which is one that affects less than 200,000 persons in the United States." In the European Union (EU), the European Medicines Agency (EMA) defined a drug as "orphan" if it is intended for the diagnosis, prevention or treatment of a life-threatening or chronically and seriously debilitating condition affecting not more up to 10,000 EU people | https://en.wikipedia.org/wiki?curid=395889 |
Orphan drug EMA also qualified an orphan drug that – without incentives – it would be unlikely that marketing the drug in the EU would generate sufficient benefit for the affected people and for the drug manufacturer to justify the investment. As of 2017, there was no official integration of the orphan drug programs between the FDA and EMA. , there were 281 marketed orphan drugs and more than 400 orphan-designated drugs in clinical trials. More than 60% of orphan drugs were biologics. The U.S. dominated development of orphan drugs, with more than 300 in clinical trials, followed by Europe. Cancer treatment was the indication in more than 30% of orphan drug trials. According to Thomson Reuters in their 2012 publication "The Economic Power of Orphan Drugs," there has been increased investment in orphan drug research and development, partly due to the U. S. Orphan Drug Act of 1983 (ODA) and similar acts in other regions of the world driven by "high-profile philanthropic funding." According to "Drug Discovery Today", the years 2001 to 2011 were the "most productive period in the history of orphan drug development, in terms of average annual orphan drug designations and orphan drug approvals." For the same decade the compound annual growth rate (CAGR) of the orphan drugs was an "impressive 25.8%, compared to only 20.1% for a matched control group of non-orphan drugs." By 2012, the market for orphan drugs was worth USD$637 million, compared with USD$638 million for a control group of non-orphan drugs | https://en.wikipedia.org/wiki?curid=395889 |
Orphan drug By 2012, According to a 2014 report, the orphan drug market has become increasingly lucrative for a number of reasons. The cost of clinical trials for orphan drugs is substantially lower than for other diseases because trial sizes are naturally much smaller than for more diseases with larger numbers of patients. Small clinical trials and minimal competition place orphan agents at an advantage in regulatory review. Tax incentives reduce the cost of development. On average the cost per patient for orphan drugs is "six times that of non-orphan drugs, a clear indication of their pricing power." The cost of per-person outlays are large and are expected to increase with wider use of public subsidies. The 2014 Orphan Drug report stated that the percentage of orphan drug sales as part of all prescription drug sales had been increasing at rapid rate. The report projected a total of US$176 billion by 2020. Although orphan disease populations are the smallest, the cost of per-patient outlays among them are the largest and are expected to increase as more people with rare diseases become eligible for subsidies — in the U.S., for example, through the Affordable Care Act. Orphan drugs generally follow the same regulatory development path as any other pharmaceutical product, in which testing focuses on pharmacokinetics and pharmacodynamics, dosing, stability, safety and efficacy. However, some statistical burdens are lessened to maintain development momentum | https://en.wikipedia.org/wiki?curid=395889 |
Orphan drug For example, orphan drug regulations generally acknowledge the fact that it may not be possible to test 1,000 patients in a phase III clinical trial if fewer than that number are afflicted with the disease. Government intervention on behalf of orphan drug development takes several forms: A 2015 study of "34 key Canadian stakeholders, including drug regulators, funders, scientists, policy experts, pharmaceutical industry representatives, and patient advocates" investigated factors behind the pharmaceutical industry growing interest in "niche markets" such as orphan drugs. The Orphan Drug Act (ODA) of January 1983, passed in the United States, with lobbying from the National Organization for Rare Disorders and many other organizations, is meant to encourage pharmaceutical companies to develop drugs for diseases that have a small market. Under the ODA drugs, vaccines, and diagnostic agents would qualify for orphan status if they were intended to treat a disease affecting fewer than 200,000 American citizens. Under the ODA orphan drug sponsors qualify for seven-year FDA-administered market Orphan Drug Exclusivity (ODE), "tax credits of up to 50% of R&D costs, R&D grants, waived FDA fees, protocol assistance and may get clinical trial tax incentives. In the U.S., orphan drug designation means that the sponsor qualifies for certain benefits, but it does not mean the drug is safe, effective or legal. In 2002, the Rare Diseases Act was signed into law | https://en.wikipedia.org/wiki?curid=395889 |
Orphan drug It amended the Public Health Service Act to establish the Office of Rare Diseases. It also increased funding for the development of treatments for people with rare diseases. In 2000, the European Union (EU) enacted similar legislation, Regulation(EC) No 141/2000, which refers to drugs developed to treat rare diseases to as "orphan medicinal products". The EU's definition of an orphan condition is broader than that of the USA, in that it also covers some tropical diseases that are primarily found in developing nations. status granted by the European Commission gives marketing exclusivity in the EU for 10 years after approval. The EU's legislation is administered by the Committee on Orphan Medicinal Products of the European Medicines Agency (EMA). In late 2007 the FDA and EMA agreed to use a common application process for both agencies to make it easier for manufacturers to apply for orphan drug status but, while continuing two separate approval processes. Legislation has been implemented by Japan, Singapore, and Australia that offers subsidies and other incentives to encourage the development of drugs that treat orphan diseases. Under the ODA and EU legislation, many orphan drugs have been developed, including drugs to treat glioma, multiple myeloma, cystic fibrosis, phenylketonuria, snake venom poisoning, and idiopathic thrombocytopenic purpura. The Pharmaceutical Executive opines, that the "ODA is nearly universally acknowledged to be a success" | https://en.wikipedia.org/wiki?curid=395889 |
Orphan drug Before the United States Congress enacted the ODA in 1983, only 38 drugs were approved in the USA specifically to treat orphan diseases. In the USA, from January 1983 to June 2004, the Office of Orphan Products Development 249 orphan drugs received marketing authorization and granted 1,129 different orphan drug designations, compared to fewer than ten such products in the decade prior to 1983. From 1983 until May 2010, the FDA approved 353 orphan drugs and granted orphan designations to 2,116 compounds. As of 2010, 200 of the roughly 7,000 officially designated orphan diseases have become treatable. Critics have questioned whether orphan drug legislation was the real cause of this increase, claiming that many of the new drugs were for disorders which were already being researched anyway, and would have had drugs developed regardless of the legislation, and whether the ODA has truly stimulated the production of non-profitable drugs; the act also has been criticised for allowing some pharmaceutical companies to make a large profit of drugs which have a small market but sell for a high price. While the European Medicines Agency grants orphan drugs market access to all member states, in practice, they only reach the market when a member state decides that its national health system will reimburse for the drug. For example, in 2008, 44 orphan drugs reached the market in the Netherlands, 35 in Belgium, and 28 in Sweden, while in 2007, 35 such drugs reached the market in France and 23 in Italy | https://en.wikipedia.org/wiki?curid=395889 |
Orphan drug Though not technically an orphan disease, the research and development into the treatment for AIDS has been heavily linked to the Orphan Drug Act. In the beginning of the AIDS epidemic the lack of treatment for the disease was often accredited to a believed lack of commercial base for a medication linked to HIV infection. This encouraged the FDA to use the Orphan Drug Act to help bolster research in this field, and by 1995 13 of the 19 drugs approved by the FDA to treat AIDS had received orphan drug designation, with 10 receiving marketing rights. These are in addition to the 70 designated orphan drugs designed to treat other HIV related illnesses. In the 1980s, people with cystic fibrosis rarely lived beyond their early teens. Drugs like Pulmozyme and tobramycin, both developed with aid from the ODA, revolutionized treatment for cystic fibrosis patients by significantly improving their quality of life and extending their life expectancies. Now, cystic fibrosis patients often survive into their thirties and some into their fifties. The 1985 Nobel Prize for medicine went to two researchers for their work related to familial hypercholesterolemia, which causes large and rapid increases in cholesterol levels. Their research led to the development of statin drugs which are now commonly used to treat high cholesterol. Penicillamine was developed to treat Wilson's disease, a rare hereditary disease that can lead to a fatal accumulation of copper in the body | https://en.wikipedia.org/wiki?curid=395889 |
Orphan drug This drug was later found to be effective in treating arthritis. Bis-choline tetrathiomolybdate is currently under investigation as a therapy against Wilson's disease. In 2017, FDA granted RT001 orphan drug designation in the treatment of phospholipase 2G6-associated neurodegeneration (PLAN). The Center for Orphan Drug Research at the University of Minnesota College of Pharmacy helps small companies with insufficient in-house expertise and resources in drug synthesis, formulation, pharmacometrics, and bio-analysis. The Keck Graduate Institute Center for Rare Disease Therapies (CRDT) in Claremont, California, supports projects to revive potential orphan drugs whose development has stalled by identifying barriers to commercialization, such as problems with formulation and bio-processing. Numerous advocacy groups such as the National Organization for Rare Disorders, Global Genes Project, Children's Rare Disease Network, Abetalipoproteinemia Collaboration Foundation, Zellweger Baby Support Network, and the Friedreich's Ataxia Research Alliance have been founded in order to advocate on behalf of patients suffering from rare diseases with a particular emphasis on diseases that afflict children. According to a 2015 report published by EvaluatePharma, the economics of orphan drugs mirrors the economics of the pharmaceutical market as a whole but has a few very large differences | https://en.wikipedia.org/wiki?curid=395889 |
Orphan drug The market for orphan drugs is by definition very small, but while the customer base is drastically smaller the cost of research and development is very much the same as for non orphan drugs. This, the producers have claimed, causes them to charge extremely high amounts for treatment, sometimes as high as $700,000 a year, as in the case of Spinraza (Biogen), FDA approved in December 2016 for spinal muscular atrophy, placing a large amount of stress on insurance companies and patients. An analysis of 12 orphan drugs that were approved in the US between 1990 and 2000 estimated a price reduction of on average 50% upon loss of marketing exclusivity, with a range of price reductions from 14% to 95%. Governments have implemented steps to reduce high research and development cost with subsidies and other forms of financial assistance. The largest assistance are tax breaks which can be as high as 50% of research and development costs. manufacturers are also able to take advantage of the small customer base to cut cost on clinical trials due to the small number of cases to have smaller trials which reduces cost. These smaller clinical trials also allow orphan drugs to move to market faster as the average time to receive FDA approval for an orphan drug is 10 months compared to 13 months for non-orphan drugs | https://en.wikipedia.org/wiki?curid=395889 |
Orphan drug This is especially true in the market for cancer drugs, as a 2011 study found that between 2004 and 2010 orphan drug trials were more likely to be smaller and less randomized than their non-orphan counterparts, but still had a higher FDA approval rate, with 15 orphan cancer drugs being approved, while only 12 non-orphan drugs were approved. This allows manufactures to get cost to the point that it is economically feasible to produce these treatments. The subsidies can total up to 30 million dollars per fiscal year in the United States alone . By 2015, industry analysts and academic researchers agreed, that the sky-high price of orphan drugs, such as eculizumab, was not related to research, development and manufacturing costs. Their price is arbitrary and they have become more profitable than traditional medicines. By 2007 the use of economic evaluation methods regarding public-funding of orphan drugs, using estimates of the incremental cost-effectiveness, for example, became more established internationally. The QALY has often been used in cost-utility analysis to calculate the ratio of cost to QALYs saved for a particular health care intervention. By 2008 the National Institute for Health and Care Excellence (NICE) in England and Wales, for example, operated with a threshold range of £20,000–30,000 per quality-adjusted life year (QALY). By 2005 doubts were raised about the use of economic evaluations in orphan drugs | https://en.wikipedia.org/wiki?curid=395889 |
Orphan drug By 2008 most of the orphan drugs appraised had cost-effectiveness thresholds "well in excess of the 'accepted' level and would not be reimbursed according to conventional criteria." As early as 2005 McCabe et al. argued that rarity should not have a premium and orphan drugs should be treated like other pharmaceuticals in general. Drummond et al. argued that the social value of health technologies should also be included in the assessment along with the estimation of the incremental cost-effectiveness ratio. The very large incentives given to pharmaceutical companies to produce orphan drugs have led to the impression that the financial support afforded to make these drugs possible is akin to abuse. Because drugs can be used to treat multiple conditions, companies can take drugs that were filed with their government agency as orphan drugs to receive financial assistance, and then market it to a wide population to increase their profit margin. For example AstraZeneca's cholesterol drug Crestor was filed as a treatment for the rare disease pediatric familial hypercholesterolemia. After the drug was approved for orphan drug designation, and AstraZeneca had received tax breaks and other advantages, AstraZeneca later applied and received FDA approval for the drug to be used to treat cholesterol in all diabetics. By 2008 if an orphan drug cost more than £30,000 the NICE required other arguments for funding | https://en.wikipedia.org/wiki?curid=395889 |
Orphan drug In 2015, NICE held consultations with "patient groups, the Department of Health, companies, learned societies, charities and researchers" regarding the appraisal of medicines and other technologies. There was a call for more research into new processes including the | https://en.wikipedia.org/wiki?curid=395889 |
Quantum solvent A quantum solvent is essentially a superfluid (aka a quantum liquid) used to dissolve another chemical species. Any superfluid can theoretically act as a quantum solvent, but in practice the only viable superfluid medium that can currently be used is helium-4, and it has been successfully accomplished in controlled conditions. Such solvents are currently under investigation for use in spectroscopic techniques in the field of analytical chemistry, due to their superior kinetic properties. Any matter dissolved (or otherwise suspended) in the superfluid will tend to aggregate together in clumps, encapsulated by a 'quantum solvation shell'. Due to the totally frictionless nature of the superfluid medium, the entire object then proceeds to act very much like a nanoscopic ball bearing, allowing effectively complete rotational freedom of the solvated chemical species. A quantum solvation shell consists of a region of non-superfluid helium-4 atoms that surround the molecule(s) and exhibit adiabatic following around the centre of gravity of the solute. As such, the kinetics of an effectively gaseous molecule can be studied without the need to use an actual gas (which can be impractical or impossible). It is necessary to make a small alteration to the rotational constant of the chemical species being examined, in order to compensate for the higher mass entailed by the quantum solvation shell | https://en.wikipedia.org/wiki?curid=399116 |
Quantum solvent Quantum solvation has so far been achieved with a number of organic, inorganic and organometallic compounds, and it has been speculated that as well as the obvious use in the field of spectroscopy, quantum solvents could be used as tools in nanoscale chemical engineering, perhaps to manufacture components for use in nanotechnology. | https://en.wikipedia.org/wiki?curid=399116 |
Franco Andrea Bonelli (10 November 1784 – 18 November 1830) was an Italian ornithologist, entomologist and collector. Very little is known about the early life of Bonelli: he was born in Cuneo and was interested from an early age in the fauna which surrounded him, making collecting trips, preparing specimens and noting his observations. He became a member of the Reale Società Agraria di Torino in 1807 when he presented his first studies relating to the Coleoptera of Piedmont. The high quality of these studies attracted the interest of the naturalists of his time. In April 1810, George Vat was sent to Turin by the French government to reorganize the University of Turin and begin its fusion with the Impériale University founded by Napoleon. Vat was very impressed by Bonelli's knowledge. Vat encouraged him to further his knowledge by coming to follow courses at the Natural History Museum in Paris. Bonelli took this advice so as obtain a professor's chair in the new university. In September 1810, he arrived in Paris. In 1811, Bonelli was finally named professor of zoology at the University of Turin and keeper of the natural history museum of zoology. During his time at the university, he formed one of the largest ornithological collections in Europe. In 1811, Bonelli wrote a "Catalogue of the Birds of Piedmont", in which he described 262 species. In 1815, he discovered the bird Bonelli's warbler ("Phylloscopus bonelli"), named by Louis Vieillot in 1819 | https://en.wikipedia.org/wiki?curid=401155 |
Franco Andrea Bonelli In the same year, he discovered Bonelli's eagle ("Hieraaetus fasciatus") that was likewise named by Vieillot in 1822. The successor of Bonelli at the Turin Museum was Carlo Giuseppe Gené. Bonelli is most notable for his work on birds and on the beetle family Carabidae. Since he was an early worker on Coleoptera many of his genera later became Families, sub families and tribes. Also many of his genera survive. Instances are the: The last two are founding works of entomology, introducing many new taxa. | https://en.wikipedia.org/wiki?curid=401155 |
Speed prior The speed prior is a complexity measure similar to Kolmogorov complexity, except that it is based on computation speed as well as program length. The speed prior complexity of a program is its size in bits plus the logarithm of the maximum time we are willing to run it to get a prediction. When compared to traditional measures, use of the Speed Prior has the disadvantage of leading to less optimal predictions, and the advantage of providing computable predictions. | https://en.wikipedia.org/wiki?curid=402703 |
Karelides The are an ancient mountain chain located between Eastern Finland and Lapland. It forms the current hill zone of Eastern Finland and Lapland's arctic hills, splitting central Finland. The formed about 2000 million years ago, when thick sandstone formations were tilted and folded during an orogeny involving a collision of continental plates. Subsequent erosion has left a ridge of resistant quartzite, which has stood there for millions of years. The mountains in the north-west corner of Finnish Lapland belong to the more recent Scandinavian Mountains and are higher than other Finnish mountains. The third mountain group is the Svecofennides, which run from Southern Finland to Sweden. | https://en.wikipedia.org/wiki?curid=411623 |
Research Triangle The Research Triangle, commonly referred to as simply The Triangle, is a region in the Piedmont of North Carolina in the United States, anchored by the three major research universities of North Carolina State University, Duke University, and University of North Carolina at Chapel Hill, as well as the cities of Raleigh and Durham and the town of Chapel Hill. The nine-county region, officially named the Raleigh–Durham–Cary combined statistical area (CSA), comprises the Raleigh–Cary and Durham–Chapel Hill Metropolitan Statistical Areas and the Henderson Micropolitan Statistical Area. A 2019 Census estimate put the population at 2,079,687, making it the second largest combined statistical area in the state of North Carolina behind Charlotte CSA. The Raleigh–Durham television market includes a broader 24-county area which includes Fayetteville, North Carolina, and has a population of 2,726,000 persons. The "Triangle" name was cemented in the public consciousness in the 1950s with the creation of Park, home to numerous tech companies and enterprises. Although the name is now used to refer to the geographic region, "the Triangle" originally referred to the universities, whose research facilities, and the educated workforce they provide, have historically served as a major attraction for businesses located in the region. Most of the Triangle is part of North Carolina's first, second, and fourth congressional districts | https://en.wikipedia.org/wiki?curid=411765 |
Research Triangle The region is sometimes confused with The Triad, which is a North Carolina region adjacent to and directly west of the Triangle comprising Greensboro, Winston-Salem, and High Point, among other cities. Depending on which definition of the region is used, as few as three or as many as 16 counties are included as part of the region. All of these counties when included hold a population of over 2,167,000 people. The three core counties of Wake, Durham and Orange are the homes of the three research universities for which the area is named. The 2019 members of the Regional Partnership are: All counties in the State of North Carolina are in one of 16 regional councils which provide programs and services to local governments. The Triangle J Council of Governments includes Chatham, Durham, Johnston, Lee, Moore, Orange, and Wake Counties. The northern Triangle counties of Person, Granville, Franklin, Vance and Warren are part of the Kerr-Tar Regional Council of Governments. As of September 14, 2018, the US Office of Management and Budget (OMB) delineated the Raleigh-Durham-Cary Combined Statistical Area as consisting of two metropolitan and one micropolitan statistical areas. Those three statistical areas in turn are defined as consisting of a total of nine counties. The MSAs and their constituent counties are: Prior to September 2018, the OMB had used the name Raleigh-Durham-Chapel Hill Combined Statistical Area and it included several additional counties | https://en.wikipedia.org/wiki?curid=411765 |
Research Triangle The Dunn Micropolitan Statistical Area (Harnett County) and Sanford Micropolitan Statistical Area (Lee County) were moved to the Fayetteville-Sanford-Lumberton Combined Statistical Area, while the Oxford Micropolitan Statistical Area (Granville County) was folded into the Durham-Chapel Hill Metropolitan Statistical Area. The Raleigh Metropolitan Statistical Area was also renamed the Raleigh-Cary Metropolitan Statistical Area. The table below outlines the populations of the constituent counties of the Raleigh–Durham-Cary Combined Statistical Area as of July 1, 2019. The Triangle region, as defined for statistical purposes as the Raleigh–Durham–Cary CSA, comprises nine counties, although the U.S. Census Bureau divided the region into two metropolitan statistical areas and one micropolitan area in 2003. The Raleigh-Cary metropolitan area comprises Wake, Franklin, and Johnston Counties; the Durham-Chapel Hill metropolitan area comprises Durham, Orange, Chatham, Granville, and Person Counties; and the Henderson micropolitan area comprises Vance County. Some area television stations define the region as Raleigh–Durham–Fayetteville. Fayetteville is more than from Raleigh, but is part of the Triangle television market. Public secondary education in the Triangle is similar to that of the majority of the state of North Carolina, in which there are county-wide school systems (the exception is Chapel Hill-Carrboro City Schools within Orange County but apart from Orange County Schools) | https://en.wikipedia.org/wiki?curid=411765 |
Research Triangle Based in Cary, the Wake County Public School System, which includes the cities of Raleigh and Cary, is the largest school system in the state of North Carolina and the 15th-largest in the United States, with average daily enrollment of 159,949 as of the second month of the 2016–17 school year. Other larger systems in the region include Durham Public Schools (about 33,000 students) and rapidly growing Johnston County Schools (about 31,000 students). With the significant number of universities and colleges in the area and the relative absence of major league professional sports, NCAA sports are very popular, particularly those sports in which the Atlantic Coast Conference participates, most notably basketball. The Duke Blue Devils (representing Duke University in Durham), NC State Wolfpack (representing North Carolina State University in Raleigh), and North Carolina Tar Heels (representing the University of North Carolina at Chapel Hill) are all members of the ACC. Rivalries among these schools are very strong, fueled by proximity to each other, with annual competitions in every sport. Adding to the rivalries is the large number of graduates the high schools in the region send to each of the local universities. It is very common for students at one university to know many students attending the other local universities, which increases the opportunities for "bragging" among the schools | https://en.wikipedia.org/wiki?curid=411765 |
Research Triangle The four ACC schools in the state, Duke, North Carolina, North Carolina State, and Wake Forest University (the last of which was originally located in the town of Wake Forest before moving to Winston-Salem in 1956), are referred to as Tobacco Road by sportscasters, particularly in basketball. All four teams consistently produce high-caliber teams. Each of the Triangle-based universities listed has won at least two NCAA Basketball national championships. Three historically black colleges, including recent Division I arrival North Carolina Central University and Division II members St. Augustine College and Shaw University also boost the popularity of college sports in the region. Other colleges in the Triangle that field intercollegiate teams include Campbell University, Meredith College, and William Peace University. The region has only one professional team of the four major sports, the Carolina Hurricanes of the NHL, based in Raleigh. Since moving to the region from Hartford, Connecticut, they have enjoyed great success, including winning a Stanley Cup. With only one top-level professional sports option, minor league sports are quite popular in the region. The Durham Bulls in downtown Durham are a AAA Minor League baseball affiliate of the Tampa Bay Rays, and the Carolina Mudcats, based in Zebulon, 10 miles east of Raleigh, are the Advanced-A affiliate of the Milwaukee Brewers | https://en.wikipedia.org/wiki?curid=411765 |
Research Triangle In Cary, North Carolina FC plays in the second-level United Soccer League, and the North Carolina Courage began play in the National Women's Soccer League in 2017 after the owner of North Carolina FC bought the NWSL franchise rights of the Western New York Flash and relocated the NWSL franchise to the Triangle. The area also had a team in the fledgling World League of American Football – however, the Raleigh–Durham Skyhawks, coached by Roman Gabriel, did not exactly cover themselves in glory; they lost all 10 games of their inaugural (and only) season in 1991. The team folded after that, being replaced in the league by the Ohio Glory, which fared little better at 1–9, ultimately suffering the same fate – along with the other six teams based in North America – when the league took a two-year hiatus, returning as a six-team all-European league in 1995. Anchored by leading technology firms, government and world-class universities, medical centers and schools, the area's economy has performed exceptionally well. Significant increases in employment, earnings, personal income, and retail sales are projected over the next 15 years. The region's growing high-technology community includes such companies as IBM, SAS Institute, Cisco Systems, NetApp, Red Hat, EMC Corporation, and Credit Suisse First Boston. In addition to high-tech, the region is consistently ranked in the top three in the U.S. with concentration in life science companies. Some of these companies include GlaxoSmithKline, Biogen Idec, BASF, Merck & Co | https://en.wikipedia.org/wiki?curid=411765 |
Research Triangle , Novo Nordisk, Novozymes, and Pfizer. Park and North Carolina State University's Centennial Campus in Raleigh support innovation through R&D and technology transfer among the region's companies and research universities (including Duke University and the University of North Carolina at Chapel Hill). The area fared relatively well during the late-2000s recession, ranked as the strongest region in North Carolina by the Brookings Institution and among the top 40 in the country. The change in unemployment during 2008 to 2009 was 4.6% and home prices was 2%. The Greensboro metropolitan area was listed among the second-weakest and the Charlotte area among the middle in the country. The region is served by these hospitals and medical centers: The Triangle proper is served by three major interstate highways: I-40, I-85, and I-87 along with their spurs: I-440 and I-540, and seven U.S. Routes: 1, 15, 64, 70, 264, 401, and 501. US Highways 15 and 501 are multiplexed through much of the region as US 15-501. I-95 passes 30 miles east of Raleigh through Johnston County, with I-87 connecting I-95 at Rocky Mount, NC to Raleigh via the US 64–264 Bypass. The two interstates diverge from one another in Orange County, with I-85 heading northeast through northern Durham County toward Virginia, while I-40 travels southeast through southern Durham, through the center of the region, and serves as the primary freeway through Raleigh. The related loop freeways I-440 and I-540 are primarily located in Wake County around Raleigh | https://en.wikipedia.org/wiki?curid=411765 |
Research Triangle I-440 begins at the interchange of US 1 and I-40 southwest of downtown Raleigh and arcs as a multiplex with US 1 northward around downtown with the formal designation as the Cliff Benson/Raleigh Beltline (cosigned with US 1 on three-fourths of its northern route) and ends at its junction with I-40 in southeast Raleigh. I-540, sometimes known as the Raleigh Outer Loop, extends from the US 64–264 Bypass to I-40 just inside Durham County, where it continues across the interstate as a state route (NC 540), prior to its becoming a toll road from the NC 54 interchange to the current terminus at NC Highway 55 near Holly Springs. I-95 serves the extreme eastern edge of the region, crossing north–south through suburban Johnston County. U.S. Routes 1, 15, and 64 primarily serve the region as limited-access freeways or multilane highways with access roads. US 1 enters the region from the southwest as the Claude E. Pope Memorial Highway and travels through suburban Apex where it merges with US 64 and continues northeast through Cary. The two highways are codesignated for about until US 1 joins I-440 and US 64 with I-40 along the Raleigh–Cary border. Capital Boulevard, which is designated US 1 for half of its route and US 401 the other is not a limited-access freeway, although it is a major thoroughfare through northeast Raleigh and into the northern downtown area. North Carolina Highway 147 is a limited-access freeway that connects I-85 with Toll Route NC 540 in northwestern Wake County | https://en.wikipedia.org/wiki?curid=411765 |
Research Triangle The older, toll-free portion of the four-lane route—known as the Durham Freeway or the I.L. "Buck" Dean Expressway—traverses downtown Durham and extends through Park to I-40. The Durham Freeway is often used as a detour or alternate route for I-40 through southwestern Durham the Chapel Hill area in cases of traffic accident, congestion or road construction delays. The tolled portion of NC 147, called the Triangle Expressway—North Carolina's first modern toll road when it opened to traffic in late 2011—continues past I-40 to Toll NC 540. Both Toll NC 147 and Toll NC 540 are modern facilities which collect tolls using transponders and license plate photo-capture technology. A partnering system of multiple public transportation agencies currently serves the Triangle region under the joint GoTransit branding. Raleigh is served by the Capital Area Transit (CAT) municipal transit system, while Durham has the Durham Area Transit Authority (DATA) system. Chapel Hill is served by Chapel Hill Transit, and Cary is served by C-Tran public transit systems. However, Triangle Transit, formerly called the Triangle Transit Authority (TTA), works in cooperation with all area transit systems by offering transfers between its own routes and those of the other systems. Triangle Transit also coordinates an extensive vanpool and rideshare program that serves the region's larger employers and commute destinations | https://en.wikipedia.org/wiki?curid=411765 |
Research Triangle Plans have been made to merge all of the area's municipal systems into Triangle Transit, and Triangle Transit also has proposed a regional rail system to connect downtown Durham, downtown Cary and downtown Raleigh with multiple suburban stops, as well as stops in the Park area. The agency's initial proposal was effectively cancelled in 2006, however, when the agency could not procure adequate federal funding. A committee of local business, transportation and government leaders currently are working with Triangle Transit to develop a new transit blueprint for the region, with various modes of rail transit, as well as bus rapid transit, open as options for consideration. Raleigh–Durham International Airport (RDU) has nonstop passenger service to 68 destinations with over 450 average daily departures, including nonstop international service to Canada, Europe, and Mexico. It is located near the geographic center of The Triangle, northeast of the town of Morrisville in Wake County. The airport covers 5,000 acres (2,023 ha) and has three runways. In 1939 the General Assembly of North Carolina chartered the Raleigh–Durham Aeronautical Authority, which was changed in 1945 to the Raleigh–Durham Airport Authority. The first new terminal opened in 1955. Terminal A (now Terminal 1) opened in 1981. American Airlines began service to RDU in 1985. RDU opened the runway, 5L-23R, in 1986 | https://en.wikipedia.org/wiki?curid=411765 |
Research Triangle American Airlines opened its north–south hub operation at RDU in the new Terminal C in June 1987, greatly increasing the size of RDU's operations with a new terminal including a new apron and runway. American brought RDU its first international flights to Bermuda, Cancun, Paris and London. In 1996, American Airlines ceased its hub operations at RDU due to Pan Am and Eastern Airlines. Pan Am and Eastern were Miami's main tenants until 1991, when both carriers went bankrupt. Their hubs at MIA were taken over by United Airlines and American Airlines. This created a difficulty in competing with US Airways' hub in Charlotte and Delta Air Lines' hub in Atlanta, Georgia for passengers traveling between smaller cities in the North and South. Midway Airlines entered the market, starting service in 1995 with the then somewhat novel concept of 50-seat Canadair Regional Jets providing service from its RDU hub primarily along the East Coast. Midway, originally incorporated in Chicago, had some success after moving its operations to the midpoint of the eastern United States at RDU and its headquarters to Morrisville, NC. The carrier ultimately could not overcome three weighty challenges: the arrival of Southwest Airlines, the refusal of American Airlines to renew the frequent flyer affiliation it had with Midway (thus dispatching numerous higher fare-paying businesspeople to airlines with better reward destinations), and the significant blow of September 11, 2001 | https://en.wikipedia.org/wiki?curid=411765 |
Research Triangle Midway Airlines filed Chapter 11 bankruptcy on August 13, 2001, and ceased operations entirely on October 30, 2003. In February 2000, RDU was ranked as the nation's second fastest-growing major airport in the United States, by Airports Council International, based on 1999 statistics. Passenger growth hit 24% over the previous year, ranking RDU second only to Washington Dulles International Airport. RDU opened Terminal A south concourse for use by Northwest and Continental Airlines in 2001. The addition added and five aircraft gates to the terminal. Terminal A became designated as Terminal 1 on October 26, 2008. In 2003, RDU also dedicated a new general aviation terminal. RDU continues to keep pace with its growth by redeveloping Terminal C into a new state-of-the-art terminal, now known as Terminal 2, which opened in October 2008. Carriers at RDU International Airport: In addition to RDU, several smaller publicly owned general-aviation airports also operate in the metropolitan region: Several licensed private general-aviation and agricultural airfields are located in the region's suburban areas and nearby rural communities: These licensed heliports serve the region: A number of helipads (i.e. marked landing sites not classified under the FAA LID system) also serve a variety of additional medical facilities (such as UNC Hospitals in Chapel Hill), as well as private, corporate and governmental interests, throughout the region | https://en.wikipedia.org/wiki?curid=411765 |
Research Triangle Amtrak serves the region with the Silver Meteor, Silver Star, Palmetto, Carolinian, and Piedmont routes. "Notable shopping centers and malls:" Film festivals and events: Notable performing arts and music venues: Theatre and dance events: Music festivals: Movie theatre chains: The area is part of the Raleigh–Durham–Fayetteville television designated media area and is the 25th-largest in the country with 1,135,920 households (2014) included in that area and the second largest television market in North Carolina. It is part of the Raleigh–Durham Nielsen Audio radio market (code 115) and is the 42nd-largest in the country with a population of 1,365,900. The Raleigh–Durham–Fayetteville market is defined by Nielsen as including Chatham, Cumberland, Dunn, Durham, Granville, Halifax, Harnett, Hoke, Johnston, Lee, Moore, Northampton, Orange, Robeson, Vance, Wake, Warren, Wayne, and Wilson Counties, along with parts of Franklin County. Numerous newspapers and periodicals serve the Triangle market. The Triangle is part of the Raleigh–Durham–Fayetteville Designated Market Area for broadcast television. –16, the area was the 25th-largest in the country. This area includes these television stations: Raleigh is home to the Region bureau of the regional cable TV news channel News 14 Carolina. The Triangle is home to North Carolina Public Radio, a public radio station/NPR provider that brings in listeners around the country. Raleigh and a large part of the Triangle area is Arbitron radio market #43 | https://en.wikipedia.org/wiki?curid=411765 |
Research Triangle Stations include: FM stations: AM stations: Triangle North Carolina | https://en.wikipedia.org/wiki?curid=411765 |
Staining is a technique used to enhance contrast in samples, generally at the microscopic level. Stains and dyes are frequently used in histology (the study of tissue under the microscope) and in the medical fields of histopathology, hematology, and cytopathology that focus on the study and diagnoses disease at a microscopic level. Stains may be used to define biological tissues (highlighting, for example, muscle fibers or connective tissue), cell populations (classifying different blood cells), or organelles within individual cells. In biochemistry it involves adding a class-specific (DNA, proteins, lipids, carbohydrates) dye to a substrate to qualify or quantify the presence of a specific compound. and fluorescent tagging can serve similar purposes. Biological staining is also used to mark cells in flow cytometry, and to flag proteins or nucleic acids in gel electrophoresis. is not limited to biological materials, it can also be used to study the structure of other materials for example the lamellar structures of semi-crystalline polymers or the domain structures of block copolymers. "In vivo staining" (also called vital staining or intravital staining) is the process of dyeing living tissues. By causing certain cells or structures to take on contrasting colour(s), their form (morphology) or position within a cell or tissue can be readily seen and studied | https://en.wikipedia.org/wiki?curid=411782 |
Staining The usual purpose is to reveal cytological details that might otherwise not be apparent; however, staining can also reveal where certain chemicals or specific chemical reactions are taking place within cells or tissues. "In vitro" staining involves colouring cells or structures that have been removed from their biological context. Certain stains are often combined to reveal more details and features than a single stain alone. Combined with specific protocols for fixation and sample preparation, scientists and physicians can use these standard techniques as consistent, repeatable diagnostic tools. A counterstain is stain that makes cells or structures more visible, when not completely visible with the principal stain. While ex vivo, many cells continue to live and metabolize until they are "fixed". Some staining methods are based on this property. Those stains excluded by the living cells but taken up by the already dead cells are called vital stains (e.g. trypan blue or propidium iodide for eukaryotic cells). Those that enter and stain living cells are called supravital stains (e.g. New Methylene Blue and brilliant cresyl blue for reticulocyte staining). However, these stains are eventually toxic to the organism, some more so than others. Partly due to their toxic interaction inside a living cell, when supravital stains enter a living cell, they might produce a characteristic pattern of staining different from the staining of an already fixed cell (e.g. "reticulocyte" look versus diffuse "polychromasia") | https://en.wikipedia.org/wiki?curid=411782 |
Staining To achieve desired effects, the stains are used in very dilute solutions ranging from to (Howey, 2000). Note that many stains may be used in both living and fixed cells. A common microscope used in staining is the bright-field microscope. The bright-field microscope is categorized as a light microscope because of the illuminator which produces light to create a bright background. These microscopes are usually binocular, meaning that there are two eyepieces which are typically at ten times magnification. When viewing stained organisms at one thousand times magnification, oil is needed to help create a clearer view due to the distortion of resolution from light refraction which becomes incredibly pronounced at high magnification. The preparatory steps involved depend on the type of analysis planned; some or all of the following procedures may be required. Wet Mounts- wet mounts are used to view live organisms and can be made using water and certain stains. The liquid is added to the slide before the addition of the organism and a coverslip is placed over the specimen in the water and stain to help contain it within the field of view. Fixation–which may itself consist of several steps–aims to preserve the shape of the cells or tissue involved as much as possible. Sometimes heat fixation is used to kill, adhere, and alter the specimen so it accepts stains. Most chemical fixatives (chemicals causing fixation) generate chemical bonds between proteins and other substances within the sample, increasing their rigidity | https://en.wikipedia.org/wiki?curid=411782 |
Staining Common fixatives include formaldehyde, ethanol, methanol, and/or picric acid. Pieces of tissue may be embedded in paraffin wax to increase their mechanical strength and stability and to make them easier to cut into thin slices.Mordant: These are chemical agents which have power of making dyes to stain materials which otherwise are unstainable Mordants are classified into two categories: a) Basic Mordant: React with acidic dyes e.g. alum , ferrous sulfate , cetylpyridinium chloride etc . b) Acidic Mordant : React with basic dyes e.g. picric acid , tannic acid etc. Direct Staining: Carried out without mordant. Indirect Staining: brought by the aid of a mordant. Permeabilization involves treatment of cells with (usually) a mild surfactant. This treatment dissolves cell membranes, and allows larger dye molecules into the cell's interior. Mounting usually involves attaching the samples to a glass microscope slide for observation and analysis. In some cases, cells may be grown directly on a slide. For samples of loose cells (as with a blood smear or a pap smear) the sample can be directly applied to a slide. For larger pieces of tissue, thin sections (slices) are made using a microtome; these slices can then be mounted and inspected. Most of the dyes commonly used in microscopy are available as BSC-certified stains | https://en.wikipedia.org/wiki?curid=411782 |
Staining This means that samples of the manufacturer's batch have been tested by an independent body, the Biological Stain Commission (BSC), and found to meet or exceed certain standards of purity, dye content and performance in staining techniques ensuring more accurately performed experiments and more reliable results. These standards are published in the Commission's journal Biotechnic & Histochemistry. Many dyes are inconsistent in composition from one supplier to another. The use of BSC-certified stains eliminates a source of unexpected results. Some vendors sell stains "certified" by themselves rather than by the Biological Stain Commission. Such products may or may not be suitable for diagnostic and other applications. A simple staining method for bacteria that is usually successful, even when the positive staining methods fail, is to use a negative stain. This can be achieved by smearing the sample onto the slide and then applying nigrosin (a black synthetic dye) or India ink (an aqueous suspension of carbon particles). After drying, the microorganisms may be viewed in bright field microscopy as lighter inclusions well-contrasted against the dark environment surrounding them. Negative staining is able to stain the background instead of the organisms because the cell wall of microorganisms typically has a negative charge which repels the negatively charged stain. The dyes used in negative staining are acidic | https://en.wikipedia.org/wiki?curid=411782 |
Staining Note: negative staining is a mild technique that may not destroy the microorganisms, and is therefore unsuitable for studying pathogens. Unlike negative staining, positive staining uses basic dyes to color the specimen against a bright background. While chromophore is used for both negative and positive staining alike, the type of chromophore used in this technique is a positively charged ion instead of a negative one. The negatively charged cell wall of many microorganisms attracts the positively charged chromophore which causes the specimen to absorb the stain giving it the color of the stain being used. Positive staining is more commonly used than negative staining in microbiology. The different types of positive staining are listed below. Simple is a technique that only uses one type of stain on a slide at a time. Because only one stain is being used, the specimens (for positive stains) or background (for negative stains) will be one color. Therefore, simple stains are typically used for viewing only one organism per slide. Differential staining uses multiple stains per slide. Based on the stains being used, organisms with different properties will appear different colors allowing for categorization of multiple specimens. Differential staining can also be used to color different organelles within one organism which can be seen in endospore staining. Gram staining is used to determine gram status to classifying bacteria broadly based on the composition of their cell wall | https://en.wikipedia.org/wiki?curid=411782 |
Staining Gram staining uses crystal violet to stain cell walls, iodine (as a mordant), and a fuchsin or safranin counterstain to (mark all bacteria). Gram status, proven to be relevant in the field of medicine, determines the presence or absence of a cell wall changes the bacterium's susceptibility to some antibiotics. Gram-positive bacteria stain dark blue or violet. Their cell wall is typically rich with peptidoglycan and lacks the secondary membrane and lipopolysaccharide layer found in Gram-negative bacteria. On most Gram-stained preparations, Gram-negative organisms appear red or pink due to their counterstain. Due to the presence of higher lipid content, after alcohol-treatment, the porosity of the cell wall increases, hence the CVI complex (crystal violet – iodine) can pass through. Thus, the primary stain is not retained. In addition, in contrast to most Gram-positive bacteria, Gram-negative bacteria have only a few layers of peptidoglycan and a secondary cell membrane made primarily of lipopolysaccharide. Endospore staining is used to identify the presence or absence of endospores, which make bacteria very difficult to kill. Bacterial spores have proven to be difficult to stain as they are not permeable to aqueous dye reagents. Endospore staining is particularly useful for identifying endospore-forming bacterial pathogens such as "Clostridium difficile". Prior to the development of more efficient methods, this stain was performed using the Wirtz method with heat fixation and counterstain | https://en.wikipedia.org/wiki?curid=411782 |
Staining Through the use of malachite green and a diluted ratio of carbol fuchsin, fixing bacteria in osmic acid was a great way to ensure no blending of dyes. However, newly revised staining methods have significantly decreased the time it takes to create these stains. This revision included substitution of carbol fuchsin with aqueous Safranin paired with a newly diluted 5% formula of malachite green. This new and improved composition of stains was performed in the same way as before with the use of heat fixation, rinsing, and blotting dry for later examination. Upon examination, all endospore forming bacteria will be stained green accompanied by all other cells appearing red. Ziehl-Neelsen staining is used to stain species of "Mycobacterium tuberculosis" that do not stain with the standard laboratory staining procedures such as Gram staining. This stain is performed through the use of both red coloured Carbol fuchsin that stains the bacteria and a counter stain such as Methylene blue Haematoxylin and eosin staining is frequently used in histology to examine thin tissue sections. Haematoxylin stains cell nuclei blue, while eosin stains cytoplasm, connective tissue and other extracellular substances pink or red. Eosin is strongly absorbed by red blood cells, colouring them bright red. In a skillfully made H&E preparation the red blood cells are almost orange, and collagen and cytoplasm (especially muscle) acquire different shades of pink | https://en.wikipedia.org/wiki?curid=411782 |
Staining Papanicolaou staining, or PAP staining, was developed to replace fine needle aspiration cytology (FNAC) in hopes of decreasing staining times and cost without compromising quality. This stain is a frequently used method for examining cell samples from a variety of tissue types in various organs. PAP staining has endured several modifications in order to become a “suitable alternative” for FNAC. This transition stemmed from the appreciation of wet fixed smears by scientists preserving the structures of the nuclei opposed to the opaque appearance of air dried Romanowsky smears. This led to the creation of a hybrid stain of wet fixed and air dried known as the ultrafast papanicolaou stain. This modification includes the use of nasal saline to rehydrate cells to increase cell transparency and is paired with the use of alcoholic formalin to enhance colors of the nuclei. The papanicolaou stain is now used in place of cytological staining in all organ types due to its increase in morphological quality, decreased staining time, and decreased cost. It is frequently used to stain Pap smear specimens. It uses a combination of haematoxylin, Orange G, eosin Y, Light Green SF yellowish, and sometimes Bismarck Brown Y. Periodic acid-Schiff is a histology special stain used to mark carbohydrates (glycogen, glycoprotein, proteoglycans). PAS is commonly used on liver tissue where glycogen deposits are made which is done in efforts to distinguish different types of glycogen storage diseases | https://en.wikipedia.org/wiki?curid=411782 |
Staining PAS is important because it can detect glycogen granules found in tumors of the ovaries and pancreas of the endocrine system, as well as in the bladder and kidneys of the renal system. Basement membranes can also show up in a PAS stain and can be important when diagnosing renal disease. Due to the high volume of carbohydrates within the cell wall of hyphae and yeast forms of fungi, the Periodic acid -Schiff stain can help locate these species inside tissue samples of the human body. Masson's trichrome is (as the name implies) a three-colour staining protocol. The recipe has evolved from Masson's original technique for different specific applications, but all are well-suited to distinguish cells from surrounding connective tissue. Most recipes produce red keratin and muscle fibers, blue or green staining of collagen and bone, light red or pink staining of cytoplasm, and black cell nuclei. The Romanowsky stains is considered a polychrome staining effect and is based on a combination of eosin plus (chemically reduced eosin) and demethylated methylene blue (containing its oxidation products azure A and azure B). This stain develops varying colors for all cell structures (“Romanowsky-Giemsa effect) and thus was used in staining neutrophil polymorphs and cell nuclei. Common variants include Wright's stain, Jenner's stain, May-Grunwald stain, Leishman stain and Giemsa stain. All are used to examine blood or bone marrow samples | https://en.wikipedia.org/wiki?curid=411782 |
Staining They are preferred over H&E for inspection of blood cells because different types of leukocytes (white blood cells) can be readily distinguished. All are also suited to examination of blood to detect blood-borne parasites such as malaria. Silver staining is the use of silver to stain histologic sections. This kind of staining is important in the demonstration of proteins (for example type III collagen) and DNA. It is used to show both substances inside and outside cells. Silver staining is also used in temperature gradient gel electrophoresis. "Argentaffin cells" reduce silver solution to metallic silver after formalin fixation. This method was discovered by Italian Camillo Golgi, by using a reaction between silver nitrate and potassium dichromate, thus precipitating silver chromate in some cells (see Golgi's method). A"rgyrophilic cells" reduce silver solution to metallic silver after being exposed to the stain that contains a reductant. An example of this would be hydroquinone or formalin. Sudan staining utilizes Sudan dyes to stain sudanophilic substances, often including lipids. Sudan III, Sudan IV, Oil Red O, Osmium tetroxide, and Sudan Black B are often used. Sudan staining is often used to determine the level of fecal fat in diagnosing steatorrhea. The Wirtz-Conklin stain is a special technique designed for staining true endospores with the use of malachite green dye as the primary stain and safranin as the counterstain. Once stained, they do not decolourize | https://en.wikipedia.org/wiki?curid=411782 |
Staining The addition of heat during the staining process is a huge contributing factor. Heat helps open the spore’s membrane so the dye can enter. The main purpose of this stain is to show germination of bacterial spores. If the process of germination is taking place, then the spore will turn green in color due to malachite green and the surrounding cell will be red from the safranin. This stain can also help determine the orientation of the spore within the bacterial cell; whether it being terminal (at the tip), subterminal (within the cell), or central (completely in the middle of the cell). Collagen Hybridizing Peptide (CHP) staining allows for an easy, direct way to stain denatured collagens of any type (Type I, II, IV, etc.) regardless if they were damaged or degraded via enzymatic, mechanical, chemical, or thermal means. They work by refolding into the collagen triple helix with the available single strands in the tissue. CHPs can be visualized by a simple fluorescence microscope. Different stains react or concentrate in different parts of a cell or tissue, and these properties are used to advantage to reveal specific parts or areas. Some of the most common biological stains are listed below. Unless otherwise marked, all of these dyes may be used with fixed cells and tissues; vital dyes (suitable for use with living organisms) are noted. Acridine orange (AO) is a nucleic acid selective fluorescent cationic dye useful for cell cycle determination | https://en.wikipedia.org/wiki?curid=411782 |
Staining It is cell-permeable, and interacts with DNA and RNA by intercalation or electrostatic attractions. When bound to DNA, it is very similar spectrally to fluorescein. Like fluorescein, it is also useful as a non-specific stain for backlighting conventionally stained cells on the surface of a solid sample of tissue (fluorescence backlighted staining). Bismarck brown (also Bismarck brown Y or Manchester brown) imparts a yellow colour to acid mucins. and an intense brown color to mast cells. One default of this stain is that it blots out any other structure surrounding it and makes the quality of the contrast low. It has to be paired with other stains in order to be useful. Some complimenting stains used alongside Bismark brown are Hematoxylin and Toluidine blue which provide better contrast within the histology sample. Carmine is an intensely red dye used to stain glycogen, while Carmine alum is a nuclear stain. Carmine stains require the use of a mordant, usually aluminum. Coomassie blue (also brilliant blue) nonspecifically stains proteins a strong blue colour. It is often used in gel electrophoresis. Cresyl violet stains the acidic components of the neuronal cytoplasm a violet colour, specifically nissl bodies. Often used in brain research. Crystal violet, when combined with a suitable mordant, stains cell walls purple. Crystal violet is the stain used in Gram staining. DAPI is a fluorescent nuclear stain, excited by ultraviolet light and showing strong blue fluorescence when bound to DNA | https://en.wikipedia.org/wiki?curid=411782 |
Staining DAPI binds with A=T rich repeats of chromosomes. DAPI is also not visible with regular transmission microscopy. It may be used in living or fixed cells. DAPI-stained cells are especially appropriate for cell counting. Eosin is most often used as a counterstain to haematoxylin, imparting a pink or red colour to cytoplasmic material, cell membranes, and some extracellular structures. It also imparts a strong red colour to red blood cells. Eosin may also be used as a counterstain in some variants of Gram staining, and in many other protocols. There are actually two very closely related compounds commonly referred to as eosin. Most often used is eosin Y (also known as eosin Y ws or eosin yellowish); it has a very slightly yellowish cast. The other eosin compound is eosin B (eosin bluish or imperial red); it has a very faint bluish cast. The two dyes are interchangeable, and the use of one or the other is more a matter of preference and tradition. Ethidium bromide intercalates and stains DNA, providing a fluorescent red-orange stain. Although it will not stain healthy cells, it can be used to identify cells that are in the final stages of apoptosis – such cells have much more permeable membranes. Consequently, ethidium bromide is often used as a marker for apoptosis in cells populations and to locate bands of DNA in gel electrophoresis. The stain may also be used in conjunction with acridine orange (AO) in viable cell counting | https://en.wikipedia.org/wiki?curid=411782 |
Staining This EB/AO combined stain causes live cells to fluoresce green whilst apoptotic cells retain the distinctive red-orange fluorescence. Acid fuchsine may be used to stain collagen, smooth muscle, or mitochondria. Acid fuchsin is used as the nuclear and cytoplasmic stain in Mallory's trichrome method. Acid fuchsin stains cytoplasm in some variants of Masson's trichrome. In Van Gieson's picro-fuchsine, acid fuchsin imparts its red colour to collagen fibres. Acid fuchsin is also a traditional stain for mitochondria (Altmann's method). Haematoxylin (hematoxylin in North America) is a nuclear stain. Used with a mordant, haematoxylin stains nuclei blue-violet or brown. It is most often used with eosin in the H&E stain (haematoxylin and eosin) staining, one of the most common procedures in histology. Hoechst is a "bis"-benzimidazole derivative compound that binds to the "minor groove" of DNA. Often used in fluorescence microscopy for DNA staining, Hoechst stains appear yellow when dissolved in aqueous solutions and emit blue light under UV excitation. There are two major types of Hoechst: "Hoechst 33258" and "Hoechst 33342". The two compounds are functionally similar, but with a little difference in structure. Hoechst 33258 contains a terminal hydroxyl group and is thus more soluble in aqueous solution, however this characteristics reduces its ability to penetrate the plasma membrane. Hoechst 33342 contains an ethyl substitution on the terminal hydroxyl group (i.e | https://en.wikipedia.org/wiki?curid=411782 |
Staining an ethylether group) making it more hydrophobic for easier plasma membrane passage Iodine is used in chemistry as an indicator for starch. When starch is mixed with iodine in solution, an intensely dark blue colour develops, representing a starch/iodine complex. Starch is a substance common to most plant cells and so a weak iodine solution will stain starch present in the cells. Iodine is one component in the staining technique known as Gram staining, used in microbiology. Used as a mordant in Gram's staining, iodine enhances the entrance of the dye through the pores present in the cell wall/membrane. Lugol's solution or Lugol's iodine (IKI) is a brown solution that turns black in the presence of starches and can be used as a cell stain, making the cell nuclei more visible. Used with common vinegar (acetic acid), Lugol's solution is used to identify pre-cancerous and cancerous changes in cervical and vaginal tissues during "Pap smear" follow up examinations in preparation for biopsy. The acetic acid causes the abnormal cells to blanch white, while the normal tissues stain a mahogany brown from the iodine. Malachite green (also known as diamond green B or victoria green B) can be used as a blue-green counterstain to safranin in the Gimenez staining technique for bacteria. It can also be used to directly stain spores. Methyl green is used commonly with bright-field, as well as fluorescence microscopes to dye the chromatin of cells so that they are more easily viewed | https://en.wikipedia.org/wiki?curid=411782 |
Staining Methylene blue is used to stain animal cells, such as human cheek cells, to make their nuclei more observable. Also used to stain blood films in cytology. Neutral red (or toluylene red) stains Nissl substance red. It is usually used as a counterstain in combination with other dyes. Nile blue (or Nile blue A) stains nuclei blue. It may be used with living cells. Nile red (also known as Nile blue oxazone) is formed by boiling Nile blue with sulfuric acid. This produces a mix of Nile red and Nile blue. Nile red is a lipophilic stain; it will accumulate in lipid globules inside cells, staining them red. Nile red can be used with living cells. It fluoresces strongly when partitioned into lipids, but practically not at all in aqueous solution. Osmium tetraoxide is used in optical microscopy to stain lipids. It dissolves in fats, and is reduced by organic materials to elemental osmium, an easily visible black substance. Propidium iodide is a fluorescent intercalating agent that can be used to stain cells. Propidium iodide is used as a DNA stain in flow cytometry to evaluate cell viability or DNA content in cell cycle analysis, or in microscopy to visualise the nucleus and other DNA-containing organelles. Propidium Iodide cannot cross the membrane of live cells, making it useful to differentiate necrotic, apoptotic and healthy cells | https://en.wikipedia.org/wiki?curid=411782 |
Staining PI also binds to RNA, necessitating treatment with nucleases to distinguish between RNA and DNA staining Rhodamine is a protein specific fluorescent stain commonly used in fluorescence microscopy. Safranine (or Safranine O) is a red cationic dye. It binds to nuclei (DNA) and other tissue polyanions, including glycosaminoglycans in cartilage and mast cells, and components of lignin and plastids in plant tissues. Safranine should not be confused with saffron, an expensive natural dye that is used in some methods to impart a yellow colour to collagen, to contrast with blue and red colours imparted by other dyes to nuclei and cytoplasm in animal (including human) tissues. The incorrect spelling "safranin" is in common use. The -ine ending is appropriate for safranine O because this dye is an amine, Tissues which take up stains are called chromatic. Chromosomes were so named because of their ability to absorb a violet stain. Positive affinity for a specific stain may be designated by the suffix "-philic". For example, tissues that stain with an azure stain may be referred to as azurophilic. This may also be used for more generalized staining properties, such as acidophilic for tissues that stain by acidic stains (most notably eosin), basophilic when staining in basic dyes, and "amphophilic" when staining with either acid or basic dyes. In contrast, chromophobic tissues do not take up coloured dye readily. As in light microscopy, stains can be used to enhance contrast in transmission electron microscopy | https://en.wikipedia.org/wiki?curid=411782 |
Staining Electron-dense compounds of heavy metals are typically used. Phosphotungstic acid is a common negative stain for viruses, nerves, polysaccharides, and other biological tissue materials. It is mostly used in a .5-2% ph form making it neutral and is paired with water to make an aqueous solution. Phosphotungstic acid is filled with electron dense matter that stains the background surrounding the specimen dark and the specimen itself light. This process is not the normal positive technique for staining where the specimen is dark and the background remains light. Osmium tetroxide is used in optical microscopy to stain lipids. It dissolves in fats, and is reduced by organic materials to elemental osmium, an easily visible black substance. Because it is a heavy metal that absorbs electrons, it is perhaps the most common stain used for morphology in biological electron microscopy. It is also used for the staining of various polymers for the study of their morphology by TEM. is very volatile and extremely toxic. It is a strong oxidizing agent as the osmium has an oxidation number of +8. It aggressively oxidizes many materials, leaving behind a deposit of non-volatile osmium in a lower oxidation state. Ruthenium tetroxide is equally volatile and even more aggressive than osmium tetraoxide and able to stain even materials that resist the osmium stain, e.g. polyethylene | https://en.wikipedia.org/wiki?curid=411782 |
Staining Other chemicals used in electron microscopy staining include: ammonium molybdate, cadmium iodide, carbohydrazide, ferric chloride, hexamine, indium trichloride, lanthanum nitrate, lead acetate, lead citrate, lead(II) nitrate, periodic acid, phosphomolybdic acid, potassium ferricyanide, potassium ferrocyanide, ruthenium red, silver nitrate, silver proteinate, sodium chloroaurate, thallium nitrate, thiosemicarbazide, uranyl acetate, uranyl nitrate, and vanadyl sulfate. | https://en.wikipedia.org/wiki?curid=411782 |
Human biology is an interdisciplinary area of study that examines humans through the influences and interplay of many diverse fields such as genetics, evolution, physiology, anatomy, epidemiology, anthropology, ecology, nutrition, population genetics, and sociocultural influences. It is closely related to the biomedical sciences, biological anthropology and other biological fields tying in various aspects of human functionality. It wasn't until the 20th century when biogerontologist, Raymond Pearl, founder of the journal "Human Biology", phrased the term "human biology" in a way to describe a separate subsection apart from biology. | https://en.wikipedia.org/wiki?curid=411951 |
Philip Eaton Philip E. Eaton (born 1936) is a Professor Emeritus of Chemistry at the University of Chicago. He and his fellow researchers were the first to synthesize the "impossible" cubane molecule in 1964. Working with Mao-Xi Zhang he is reported as having been the first to make octanitrocubane (their paper was published in the year 2003) Because of its eight nitro groups and highly strained C-C bonds - octanitrocubane is a very powerful high explosive. Philip E. Eaton was born in 1936 in Brooklyn, New York. When Eaton was seven his family relocated to Budd Lake, New Jersey. Here he began attending Roxbury Grammar School and later Roxbury High School. It was during these high school years that he began to find his passion for science. It was the support of his parents and teachers that made him decide to major in chemistry. Eaton attended Princeton University seeking a major in chemistry. Eaton received his B.A. in 1957 before attending Harvard University and earning his M.A. in 1960 and Ph.D. in 1961. During his time in school he became familiar with cage chemistry, specifically Kepone. Upon graduating from Harvard Eaton accepted an assistant professorship position at the University of California, Berkeley. During this time he taught introductory organic chemistry. In 1962, he transferred to the University of Chicago where he remains today. After arriving at University of Chicago Eaton began his research which he is now most well known for, cubane synthesis. In 1964 Eaton and Thomas W. Cole Jr | https://en.wikipedia.org/wiki?curid=417675 |
Philip Eaton synthesized the "impossible" cubane molecule. It was given this name because of its unusual cubic geometry. Many scientists believed that the 90 degree bond-angles would be too strained to allow this molecule to form. He later studied larger prismanes. | https://en.wikipedia.org/wiki?curid=417675 |
Mach wave In fluid dynamics, a is a pressure wave traveling with the speed of sound caused by a slight change of pressure added to a compressible flow. These weak waves can combine in supersonic flow to become a shock wave if sufficient Mach waves are present at any location. Such a shock wave is called a Mach stem or Mach front. Thus, it is possible to have shockless compression or expansion in a supersonic flow by having the production of Mach waves sufficiently spaced ("cf." isentropic compression in supersonic flows). A is the weak limit of an oblique shock wave (a normal shock is the other limit). A propagates across the flow at the Mach angle "μ", which is the angle formed between the wavefront and a vector that points opposite to the vector of motion. It is given by formula_1 where "M" is the Mach number. Mach waves can be used in schlieren or shadowgraph observations to determine the local Mach number of the flow. Early observations by Ernst Mach used grooves in the wall of a duct to produce Mach waves in a duct, which were then photographed by the schlieren method, to obtain data about the flow in nozzles and ducts. Mach angles may also occasionally be visualized out of their condensation in air, for example vapor cones around aircraft during transonic flight. | https://en.wikipedia.org/wiki?curid=418237 |
Intrinsic parity In quantum mechanics, the intrinsic parity is a phase factor that arises as an eigenvalue of the parity operation formula_1 (a reflection about the origin). To see that the parity's eigenvalues are phase factors, we assume an eigenstate of the parity operation (this is realized because the intrinsic parity is a property of a particle species) and use the fact that two parity transformations leave the particle in the same state, thus the new wave function can differ by only a phase factor, i.e.: formula_2 thus formula_3, since these are the only eigenstates satisfying the above equation. The intrinsic parity's phase is conserved for non-weak interactions (the product of the intrinsic parities is the same before and after the reaction). As formula_4 the Hamiltonian is invariant under a parity transformation. The intrinsic parity of a system is the product of the intrinsic parities of the particles, for instance for noninteracting particles we have formula_5. Since the parity commutes with the Hamiltonian and formula_6 its eigenvalue does not change with time, therefore the intrinsic parities phase is a conserved quantity. A consequence of the Dirac equation is that the intrinsic parity of fermions and antifermions obey the relation formula_7, so particles and their antiparticles have the opposite parity. Single leptons can never be created or destroyed in experiments, as lepton number is a conserved quantity | https://en.wikipedia.org/wiki?curid=418697 |
Intrinsic parity This means experiments are unable to distinguish the sign of a leptons parity, so by convention it is chosen that leptons have intrinsic parity +1, antileptons have formula_8. Similarly the parity of the quarks is chosen to be +1, and antiquarks is -1. | https://en.wikipedia.org/wiki?curid=418697 |
Ma'adim Vallis is one of the largest outflow channels on Mars, about 700 km long and significantly larger than Earth's Grand Canyon. It is over 20 km wide and 2 km deep in some places. It runs from a region of southern lowlands thought to have once contained a large group of lakes (see Eridania Lake) north to Gusev crater near the equator. It looks as if water may have collected in Gusev crater, forming a giant lake; the Spirit Rover was sent there to investigate that possibility, but found only volcanic rocks on the floor of Gusev. Any lake deposits were probably covered over by a later deposit of volcanic materials from Apollinaris Mons, a nearby volcano. is in the Aeolis quadrangle. is thought to have been carved by flowing water early in Mars' history. Some of the short narrow channels along the walls of Ma'adim are probably sapping channels. Sapping occurs when groundwater partially dissolves and undermines the rock, which collapses into debris deposits and is carried away by other erosion processes. "Ma'adim" (מאדים) is the Hebrew name of the Planet Mars. | https://en.wikipedia.org/wiki?curid=420509 |
Physical Review Focus was an internet service of the American Physical Society that began in 1998, aiming to explain new developments in physics in a language understandable to the educated non-physicist. One or two short articles were published weekly. In 2011, it merged with "Physics" (physics.aps.org) and became the Focus section of that publication. The Focus section of Physics continues to produce the same style of articles that were previously published in Physical Review Focus. The content is available without payment. The name came from the service's connection to the "Physical Review", a suite of scientific journals published by the American Physical Society. | https://en.wikipedia.org/wiki?curid=421326 |
Sleepy Hollow (Mars) Sleepy Hollow is a circular, shallow depression in Gusev Crater on Mars near the landing site of the Mars Exploration Rover "Spirit" in 2004. About from the landing site, Sleepy Hollow measures about across. The name is an allusion to the locale mentioned in Washington Irving's "The Legend of Sleepy Hollow". According to a press conference, it was the hollow where "Spirit" slept as it was checked before beginning to rove Mars. | https://en.wikipedia.org/wiki?curid=423047 |
Alginite is a component of some types of kerogen alongside amorphous organic matter. consists of organic-walled marine microfossils, distinct from inorganic (silica)-walled microfossils that comprise diatomaceous earth. is a complex soil aggregate of algae based biomass fossil, clay turned volcanic ash and calcium carbonate. This material contains a complete spectrum of minerals, biological, macro- and micro-organisms helping to turn lands fertile again in regions where soil has been severely degraded in the past. At least two forms of alginite are distinguishable, "alginite A" (telalginite) and "alginite B" (lamalginite). The "A" form contains morphologically distinguishable microfossils while the "B" form is more amorphous and film-like. | https://en.wikipedia.org/wiki?curid=428848 |
Maceral A maceral is a component, organic in origin, of coal or oil shale. The term 'maceral' in reference to coal is analogous to the use of the term 'mineral' in reference to igneous or metamorphic rocks. Examples of macerals are inertinite, vitrinite, and liptinite. Inertinite is considered to be the equivalent of charcoal and degraded plant material. It is highly oxidised in nature and may be said to be burnt. A large portion of South Africa's coal reserves consist of inertinite. Vitrinite is shiny, glass-like material that is considered to be composed of cellular plant material such as roots, bark, plant stems and tree trunks. Vitrinite macerals when observed under the microscope show a boxlike, cellular structure, often with oblong voids and cavities which are likely the remains of plant stems. This has a high calorific value (24 - 28 MJ/kg) and a large proportion of volatile matter (24 - 30%). It often occurs interbanded or interlaminated with inertinite and can be recognised as bright bands. Liptinite macerals are considered to be produced from decayed leaf matter, spores, pollen and algal matter. Resins and plant waxes can also be part of liptinite macerals. Liptinite macerals tend to retain their original plant form, i.e., they resemble plant fossils. These are hydrogen rich and have the highest calorific values of all coal macerals. Macerals of liptinite are sporinite, cutinite, resinite, alginite (telalginite and lamalginite), liptodetrinite, fluorinite, and bituminite | https://en.wikipedia.org/wiki?curid=428860 |
Maceral Macerals are considered to be dehydrogenated plant fragments. Evidence for this includes remnant pollen spores, fossilised leaves, remnant cellular structure and similar. In rare cases, maceral and fossilised pollen can be found in terrestrial sedimentary rocks. maturity can be estimated by "vitrinite reflectance". This gives information on the carbon, hydrogen and nitrogen composition of the coal, and determines the type of coal: lignite, brown coal, bituminous coal, anthracite or graphite. Macerals found in kerogen source rocks are often observed under the microscope to determine the kerogen maturity of the sedimentary formations. This is a vital component of oil and gas exploration. Macerals are observed under the petrographic microscope under reflected light. Coal fragments must be extremely highly polished down to less than half a micrometre before they can be observed under the microscope. | https://en.wikipedia.org/wiki?curid=428860 |
U-duality In physics, (short for unified duality) is a symmetry of string theory or M-theory combining S-duality and T-duality transformations. The term is most often met in the context of the "(symmetry) group" of M-theory as defined on a particular background space (topological manifold). This is the union of all the S-duality and T-duality available in that topology. The narrow meaning of the word "U-duality" is one of those dualities that can be classified neither as an S-duality, nor as a T-duality - a transformation that exchanges a large geometry of one theory with the strong coupling of another theory, for example. | https://en.wikipedia.org/wiki?curid=432624 |
Bioremediation is a process used to treat contaminated media, including water, soil and subsurface material, by altering environmental conditions to stimulate growth of microorganisms and degrade the target pollutants. In many cases, bioremediation is less expensive and more sustainable than other remediation alternatives. Biological treatment is a similar approach used to treat wastes including wastewater, industrial waste and solid waste. Most bioremediation processes involve oxidation-reduction reactions where either an electron acceptor (commonly oxygen) is added to stimulate oxidation of a reduced pollutant (e.g. hydrocarbons) or an electron donor (commonly an organic substrate) is added to reduce oxidized pollutants (nitrate, perchlorate, oxidized metals, chlorinated solvents, explosives and propellants). In both these approaches, additional nutrients, vitamins, minerals, and pH buffers may be added to optimize conditions for the microorganisms. In some cases, specialized microbial cultures are added (bioaugmentation) to further enhance biodegradation. Some examples of bioremediation related technologies are phytoremediation, mycoremediation, bioventing, bioleaching, landfarming, bioreactor, composting, bioaugmentation, rhizofiltration, and biostimulation. Most bioremediation processes involve oxidation-reduction (Redox) reactions where a chemical species donates an electron (electron donor) to a different species that accepts the electron (electron acceptor) | https://en.wikipedia.org/wiki?curid=434188 |
Bioremediation During this process, the electron donor is said to be oxidized while the electron acceptor is reduced. Common electron acceptors in bioremediation processes include oxygen, nitrate, manganese (III and IV), iron (III), sulfate, carbon dioxide and some pollutants (chlorinated solvents, explosives, oxidized metals, and radionuclides). Electron donors include sugars, fats, alcohols, natural organic material, fuel hydrocarbons and a variety of reduced organic pollutants. The redox potential for common biotransformation reactions is shown in the table. Aerobic bioremediation is the most common form of oxidative bioremediation process where oxygen is provided as the electron acceptor for oxidation of petroleum, polyaromatic hydrocarbons (PAHs), phenols, and other reduced pollutants. Oxygen is generally the preferred electron acceptor because of the higher energy yield and because oxygen is required for some enzyme systems to initiate the degradation process. Numerous laboratory and field studies have shown that microorganisms can degrade a wide variety of hydrocarbons, including components of gasoline, kerosene, diesel, and jet fuel. Under ideal conditions, the biodegradation rates of the low- to moderate-weight aliphatic, alicyclic, and aromatic compounds can be very high. As the molecular weight of the compound increases, so does the resistance to biodegradation. Common approaches for providing oxygen above the water table include landfarming, composting and bioventing | https://en.wikipedia.org/wiki?curid=434188 |
Bioremediation During landfarming, contaminated soils, sediments, or sludges are incorporated into the soil surface and periodically turned over (tilled) using conventional agricultural equipment to aerate the mixture. Composting accelerates pollutant biodegradation by mixing the waste to be treated with a bulking agent, forming into piles, and periodically mixed to increase oxygen transfer. Bioventing is a process that increases the oxygen or air flow into the unsaturated zone of the soil which increases the rate of natural in situ degradation of the targeted hydrocarbon contaminant. Approaches for oxygen addition below the water table include recirculating aerated water through the treatment zone, addition of pure oxygen or peroxides, and air sparging. Recirculation systems typically consist of a combination of injection wells or galleries and one or more recovery wells where the extracted groundwater is treated, oxygenated, amended with nutrients and reinjected. However, the amount of oxygen that can be provided by this method is limited by the low solubility of oxygen in water (8 to 10 mg/L for water in equilibrium with air at typical temperatures). Greater amounts of oxygen can be provided by contacting the water with pure oxygen or addition of hydrogen peroxide (HO) to the water. In some cases, slurries of solid calcium or magnesium peroxide are injected under pressure through soil borings. These solid peroxides react with water releasing HO which then decomposes releasing oxygen | https://en.wikipedia.org/wiki?curid=434188 |
Bioremediation Air sparging involves the injection of air under pressure below the water table. The air injection pressure must be great enough to overcome the hydrostatic pressure of the water and resistance to air flow through the soil. Anaerobic bioremediation can be employed to treat a broad range of oxidized contaminants including chlorinated ethenes (PCE, TCE, DCE, VC), chlorinated ethanes (TCA, DCA), chloromethanes (CT, CF), chlorinated cyclic hydrocarbons, various energetics (e.g., perchlorate, RDX, TNT), and nitrate. This process involves the addition of an electron donor to: 1) deplete background electron acceptors including oxygen, nitrate, oxidized iron and manganese and sulfate; and 2) stimulate the biological and/or chemical reduction of the oxidized pollutants. Hexavalent chromium (Cr[VI]) and uranium (U[VI]) can be reduced to less mobile and/or less toxic forms (e.g., Cr[III], U[IV]). Similarly, reduction of sulfate to sulfide (sulfidogenesis) can be used to precipitate certain metals (e.g., zinc, cadmium). The choice of substrate and the method of injection depend on the contaminant type and distribution in the aquifer, hydrogeology, and remediation objectives. Substrate can be added using conventional well installations, by direct-push technology, or by excavation and backfill such as permeable reactive barriers (PRB) or biowalls. Slow-release products composed of edible oils or solid substrates tend to stay in place for an extended treatment period | https://en.wikipedia.org/wiki?curid=434188 |
Bioremediation Soluble substrates or soluble fermentation products of slow-release substrates can potentially migrate via advection and diffusion, providing broader but shorter-lived treatment zones. The added organic substrates are first fermented to hydrogen (H) and volatile fatty acids (VFAs). The VFAs, including acetate, lactate, propionate and butyrate, provide carbon and energy for bacterial metabolism. Heavy metals including cadmium, chromium, lead and uranium are elements so they cannot be biodegraded. However, bioremediation processes can potentially be used to reduce the mobility of these material in the subsurface, reducing the potential for human and environmental exposure. The mobility of certain metals including chromium (Cr) and uranium (U) varies depending on the oxidation state of the material. Microorganisms can be used to reduce the toxicity and mobility of chromium by reducing hexavalent chromium, Cr(VI) to trivalent Cr (III). Uranium can be reduced from the more mobile U(VI) oxidation state to the less mobile U(IV) oxidation state. Microorganisms are used in this process because the reduction rate of these metals is often slow unless catalyzed by microbial interactions Research is also underway to develop methods to remove metals from water by enhancing the sorption of the metal to cell walls. This approach has been evaluated for treatment of cadmium, chromium, and lead. Phytoextraction processes concentrate contaminants in the biomass for subsequent removal | https://en.wikipedia.org/wiki?curid=434188 |
Bioremediation In the event of biostimulation, adding nutrients that are limited to make the environment more suitable for bioremediation, nutrients such as nitrogen, phosphorus, oxygen, and carbon may be added to the system to improve effectiveness of the treatment. Many biological processes are sensitive to pH and function most efficiently in near neutral conditions. Low pH can interfere with pH homeostasis or increase the solubility of toxic metals. Microorganisms can expend cellular energy to maintain homeostasis or cytoplasmic conditions may change in response to external changes in pH. Some anaerobes have adapted to low pH conditions through alterations in carbon and electron flow, cellular morphology, membrane structure, and protein synthesis. can be used to completely mineralize organic pollutants, to partially transform the pollutants, or alter their mobility. Heavy metals and radionuclides are elements that cannot be biodegraded, but can be bio-transformed to less mobile forms. In some cases, microbes do not fully mineralize the pollutant, potentially producing a more toxic compound. For example, under anaerobic conditions, the reductive dehalogenation of TCE may produce dichloroethylene (DCE) and vinyl chloride (VC), which are suspected or known carcinogens. However, the microorganism "Dehalococcoides" can further reduce DCE and VC to the non-toxic product ethene | https://en.wikipedia.org/wiki?curid=434188 |
Bioremediation Additional research is required to develop methods to ensure that the products from biodegradation are less persistent and less toxic than the original contaminant. Thus, the metabolic and chemical pathways of the microorganisms of interest must be known. In addition, knowing these pathways will help develop new technologies that can deal with sites that have uneven distributions of a mixture of contaminants. Also, for biodegradation to occur, there must be a microbial population with the metabolic capacity to degrade the pollutant, an environment with the right growing conditions for the microbes, and the right amount of nutrients and contaminants. The biological processes used by these microbes are highly specific, therefore, many environmental factors must be taken into account and regulated as well. Thus, bioremediation processes must be specifically made in accordance to the conditions at the contaminated site. Also, because many factors are interdependent, small-scale tests are usually performed before carrying out the procedure at the contaminated site. However, it can be difficult to extrapolate the results from the small-scale test studies into big field operations. In many cases, bioremediation takes more time than other alternatives such as land filling and incineration. The use of genetic engineering to create organisms specifically designed for bioremediation is under preliminary research | https://en.wikipedia.org/wiki?curid=434188 |
Bioremediation Two category of genes can be inserted in the organism: degradative genes which encode proteins required for the degradation of pollutants, and reporter genes that are able to monitor pollution levels. Numerous members of "Pseudomonas" have also been modified with the lux gene, but for the detection of the polyaromatic hydrocarbon naphthalene. A field test for the release of the modified organism has been successful on a moderately large scale. There are concerns surrounding release and containment of genetically modified organisms into the environment due to the potential of horizontal gene transfer. Genetically modified organisms are classified and controlled under the Toxic Substances Control Act of 1976 under United States Environmental Protection Agency. Measures have been created to address these concerns. Organisms can be modified such that they can only survive and grow under specific sets of environmental conditions. In addition, the tracking of modified organisms can be made easier with the insertion of bioluminescence genes for visual identification. Genetically modified organisms have been created to treat oil spills and break down certain plastics (PET) | https://en.wikipedia.org/wiki?curid=434188 |
International Nuclear Information System The (INIS) hosts one of the world's largest collections of published information on the peaceful uses of nuclear science and technology. INIS is based in Vienna, Austria and has been operating since 1970. INIS is operated by the IAEA (International Atomic Energy Agency) in collaboration with 127 Member States and 24 co-operating international organizations. All the content it holds is currently available free to "all Internet users around the world". | https://en.wikipedia.org/wiki?curid=437476 |
Oscar Buneman (28 September 1913 – 24 January 1993) made advances in science, engineering, and mathematics. Buneman was a pioneer of computational plasma physics and plasma simulation. In 1940 upon completion of his PhD with Douglas Hartree, Buneman joined Hartree's magnetron research group assisting the development of radar during World War II. They discovered the Buneman–Hartree criterion for the voltage threshold of a magnetron operation. After the war, Buneman developed theories and simulations of collision-less dissipation of currents called the Buneman instability. This is an example of anomalous resistivity or absorption. It is "anomalous" because the phenomenon does not depend on collisions. Buneman advanced elliptic equation solver methods and their associated applications (as well as for the fast Fourier transforms). On 24 January 1993 at the age of 79 died near Stanford University. The computer scientist Peter Buneman is his son. | https://en.wikipedia.org/wiki?curid=439569 |
Thomas Wright (geologist) Dr Thomas Wright FRS FRSE FGS (9 November 1809 – 17 November 1884) was a Scottish surgeon and palaeontologist. Wright published a number of papers on the fossils which he had collected in the Cotswolds and elsewhere, including "Lias Ammonites of the British Isles", and monographs on the British fossil echinoderms of the Oolitic (Jurassic) and Cretaceous formations. Wright was born in Paisley on 9 November 1809 the son of Thomas Wright and his wife, Barbara Jarvis, and was educated at Paisley Grammar School. He studied Medicine at the Royal College of Surgeons in Ireland based in Dublin. He returned to Scotland to practice and received his doctorate (MD) from St Andrews University in 1846. In 1846 he moved to Cheltenham, where he became medical officer of health to the urban district, and surgeon at Cheltenham General Hospital. In 1855 he was elected a Fellow of the Royal Society of Edinburgh his proposer being Sir William Jardine. In 1859 he was elected a Fellow of the Geological Society in London. He won the Wollaston Medal in 1878 and became a fellow of the Royal Society in 1879. After his death part of his fossil collection was sold to the British Museum. He married twice: firstly around 1830 to Elizabeth May; secondly in 1845 to Mary Ricketts (d.1878), youngest daughter of Sir Robert Tristram Ricketts. He had one son, Thomas Lawrence Wright, and two daughters, the elder of which married the geologist Edward Wethered. | https://en.wikipedia.org/wiki?curid=439891 |
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