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Disappearing Polymorph
In materials science, a disappearing polymorph is a form of a crystal structure (a morph) that is suddenly unable to be produced, instead transforming into a different crystal structure with the same chemical composition (a Polymorphism (materials science), polymorph) during nucleation. Sometimes the resulting transformation is extremely hard or impractical to reverse, because the new polymorph may be more Metastability, stable. That is, they are Metastability, metastable forms that have been replaced by more stable forms. It is hypothesized that contact with a single microscopic seed crystal of the new polymorph can be enough to start a chain reaction causing the transformation of a much larger mass of material. Widespread contamination with such microscopic seed crystals may lead to the impression that the original polymorph has "disappeared". In a few cases such as progesterone and paroxetine hydrochloride, the disappearance gradually spread across the world, and it is suspecte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Two Polymorphs Of 3-aminobenzenesulfonic Acid
2 (two) is a number, numeral and digit. It is the natural number following 1 and preceding 3. It is the smallest and the only even prime number. Because it forms the basis of a duality, it has religious and spiritual significance in many cultures. Mathematics The number 2 is the second natural number after 1. Each natural number, including 2, is constructed by succession, that is, by adding 1 to the previous natural number. 2 is the smallest and the only even prime number, and the first Ramanujan prime. It is also the first superior highly composite number, and the first colossally abundant number. An integer is determined to be even if it is divisible by two. When written in base 10, all multiples of 2 will end in 0, 2, 4, 6, or 8; more generally, in any even base, even numbers will end with an even digit. A digon is a polygon with two sides (or edges) and two vertices. Two distinct points in a plane are always sufficient to define a unique line in a nontrivi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gibbs Free Energy Of Crystalization
Gibbs or GIBBS is a surname and acronym. It may refer to: People * Gibbs (surname) Places * Gibbs (crater), on the Moon * Gibbs, Missouri, US * Gibbs, Tennessee, US * Gibbs Island (South Shetland Islands), Antarctica * 2937 Gibbs, an asteroid * Mount Gibbs Science Mathematics and statistics * Gibbs phenomenon * Gibbs' inequality * Gibbs sampling Physics * Gibbs phase rule * Gibbs free energy * Gibbs entropy * Gibbs paradox * Gibbs–Helmholtz equation * Gibbs algorithm * Gibbs state * Gibbs-Marangoni effect * Gibbs phenomenon, an MRI artifact Organisations * Gibbs & Cox naval architecture firm * Gothenburg International Bioscience Business School * Gibbs College, several US locations * Gibbs Technologies, developer and manufacturer of amphibious vehicles * Gibbs High School (other), several schools of this name exist * Antony Gibbs & Sons, British trading company, established in London in 1802 Other uses * Gibbs SR, former name of the toothpaste Mentadent * Gibb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States Pharmacopeia
The ''United States Pharmacopeia'' (''USP'') is a pharmacopeia (compendium of drug information) for the United States published annually by the over 200-year old United States Pharmacopeial Convention (usually also called the USP), a nonprofit organization that owns the trademark and also owns the copyright on the pharmacopeia itself. The ''USP'' is published in a combined volume with the ''National Formulary'' (a formulary) as the USP-NF. If a drug ingredient or drug product has an applicable ''USP'' quality standard (in the form of a ''USP-NF'' monograph), it must conform in order to use the designation "USP" or "NF". Drugs subject to ''USP'' standards include both human drugs ( prescription, over-the-counter, or otherwise) and animal drugs. ''USP-NF'' standards also have a role in US federal law; a drug or drug ingredient with a name recognized in ''USP-NF'' is considered adulterated if it does not satisfy compendial standards for strength, quality, or purity. USP also ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Infrared Spectroscopy
Infrared spectroscopy (IR spectroscopy or vibrational spectroscopy) is the measurement of the interaction of infrared radiation with matter by absorption, emission, or reflection. It is used to study and identify chemical substances or functional groups in solid, liquid, or gaseous forms. It can be used to characterize new materials or identify and verify known and unknown samples. The method or technique of infrared spectroscopy is conducted with an instrument called an infrared spectrometer (or spectrophotometer) which produces an infrared spectrum. An IR spectrum can be visualized in a graph of infrared light absorbance (or transmittance) on the vertical axis vs. frequency, wavenumber or wavelength on the horizontal axis. Typical units of wavenumber used in IR spectra are reciprocal centimeters, with the symbol cm−1. Units of IR wavelength are commonly given in micrometers (formerly called "microns"), symbol μm, which are related to the wavenumber in a reciprocal way ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
X-ray Crystallography
X-ray crystallography is the experimental science of determining the atomic and molecular structure of a crystal, in which the crystalline structure causes a beam of incident X-rays to Diffraction, diffract in specific directions. By measuring the angles and intensities of the X-ray diffraction, a crystallography, crystallographer can produce a three-dimensional picture of the density of electrons within the crystal and the positions of the atoms, as well as their chemical bonds, crystallographic disorder, and other information. X-ray crystallography has been fundamental in the development of many scientific fields. In its first decades of use, this method determined the size of atoms, the lengths and types of chemical bonds, and the atomic-scale differences between various materials, especially minerals and alloys. The method has also revealed the structure and function of many biological molecules, including vitamins, drugs, proteins and nucleic acids such as DNA. X-ray crystall ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Evergreening
Evergreening is any of various legal, business, and technological strategies by which producers (often pharmaceutical companies) extend the lifetime of their patents that are about to expire in order to retain revenues from them. Often the practice includes taking out new patents (for example over associated delivery systems or new pharmaceutical mixtures), or by buying out or frustrating competitors, for longer periods of time than would normally be permissible under the law. Robin Feldman, a law professor at UC Law SF and a leading researcher in intellectual property and patents, defines evergreening as "artificially extending the life of a patent or other exclusivity by obtaining additional protections to extend the monopoly period." Overview In the pharmaceutical industry, evergreening may be used by manufacturers of a particular drug to restrict or prevent competition from manufacturers of generic equivalents to that drug. Robin Feldman has documented several types of pat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Abbreviated New Drug Application
An Abbreviated New Drug Application (ANDA) is an application for a U.S. generic drug approval for an existing licensed medication or approved drug. The ANDA is submitted to FDA's Center for Drug Evaluation and Research, Office of Generic Drugs, which provides for the review and ultimate approval of a generic drug product. Once approved, an applicant may manufacture and market the generic drug product to provide a safe, effective, low cost alternative to the American public. Electronic submissions of ANDAs have grown by 70% since November 2008. The Section IV challenge has been credited with suppressing new drug innovation. A generic drug product is one that is comparable to a patented drug product in dosage form, strength, route of administration, quality, performance characteristics and intended use. All approved products, both innovator and generic, are listed in FDA's Approved Drug Products with Therapeutic Equivalence Evaluations (Orange Book). Generic drug applications are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Friedrich Wöhler
Friedrich Wöhler Royal Society of London, FRS(For) HonFRSE (; 31 July 180023 September 1882) was a German chemist known for his work in both organic chemistry, organic and inorganic chemistry, being the first to isolate the chemical elements beryllium and yttrium in pure metallic form. He was the first to prepare several inorganic compounds, including silane and silicon nitride. Wöhler is also known for seminal contributions in organic chemistry, in particular, the Wöhler synthesis of urea. His synthesis of the organic compound urea in the laboratory from inorganic substances contradicted the belief that organic compounds could only be produced by living organisms due to a "life force". However, the exact extent of Wöhler's role in diminishing the belief in vitalism is considered by some to be questionable. Biography Friedrich Wöhler was born in Eschersheim, Germany, and was the son of a veterinarian. As a boy, he showed interest in mineral collecting, drawing, and science. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Justus Von Liebig
Justus ''Freiherr'' von Liebig (12 May 1803 – 18 April 1873) was a Germans, German scientist who made major contributions to the theory, practice, and pedagogy of chemistry, as well as to agricultural and biology, biological chemistry; he is considered one of the principal founders of organic chemistry. As a professor at the University of Giessen, he devised the modern laboratory-oriented teaching method, and for such innovations, he is regarded as one of the most outstanding chemistry teachers of all time. He has been described as the "father of the fertilizer industry" for his emphasis on nitrogen and minerals as essential plant nutrients, and his popularization of the law of the minimum, which states that plant growth is limited by the scarcest nutrient resource, rather than the total amount of resources available. He also developed a manufacturing process for Meat extract, beef extracts, and with his consent a company, called Liebig Extract of Meat Company, was founded to e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Benzamide
Benzamide is an organic compound with the chemical formula of C7H7NO. It is the simplest amide derivative of benzoic acid. In powdered form, it appears as a white solid, while in crystalline form, it appears as colourless crystals. It is slightly soluble in water, and soluble in many organic solvents. It is a natural alkaloid Alkaloids are a broad class of natural product, naturally occurring organic compounds that contain at least one nitrogen atom. Some synthetic compounds of similar structure may also be termed alkaloids. Alkaloids are produced by a large varie ... found in the herbs of '' Berberis pruinosa''. Chemical derivatives A number of substituted benzamides are commercial drugs, including: See also * References External links Physical characteristics {{Authority control Phenyl compounds ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gibbs Free Energy Of Competing Polymorphs
Gibbs or GIBBS is a surname and acronym. It may refer to: People * Gibbs (surname) Places * Gibbs (crater), on the Moon * Gibbs, Missouri, US * Gibbs, Tennessee, US * Gibbs Island (South Shetland Islands), Antarctica * 2937 Gibbs, an asteroid * Mount Gibbs Science Mathematics and statistics * Gibbs phenomenon * Gibbs' inequality * Gibbs sampling Physics * Gibbs phase rule * Gibbs free energy * Gibbs entropy * Gibbs paradox * Gibbs–Helmholtz equation * Gibbs algorithm * Gibbs state * Gibbs-Marangoni effect * Gibbs phenomenon, an MRI artifact Organisations * Gibbs & Cox naval architecture firm * Gothenburg International Bioscience Business School * Gibbs College, several US locations * Gibbs Technologies, developer and manufacturer of amphibious vehicles * Gibbs High School (other), several schools of this name exist * Antony Gibbs & Sons, British trading company, established in London in 1802 Other uses * Gibbs SR, former name of the toothpaste Mentadent * Gibb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cloud Seeding
Cloud seeding is a type of weather modification that aims to change the amount or type of precipitation, mitigate hail, or disperse fog. The usual objective is to increase rain or snow, either for its own sake or to prevent precipitation from occurring in days afterward. Cloud seeding is undertaken by dispersing substances into the air that serve as Cloud condensation nuclei, cloud condensation or ice nucleus, ice nuclei. Common agents include silver iodide, potassium iodide, and dry ice, with hygroscopic materials like table salt gaining popularity due to their ability to attract moisture. Techniques vary from static seeding, which encourages ice particle formation in supercooled clouds to increase precipitation, to dynamic seeding, designed to enhance convective cloud development through the release of latent heat. Methods of dispersion include aircraft and ground-based generators, with newer approaches involving Unmanned aerial vehicle, drones delivering electric charges to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
