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Arsanilic Acid
Arsanilic acid, also known as aminophenyl arsenic acid or aminophenyl arsonic acid, is an organoarsenic compound, an amino derivative of phenylarsonic acid whose amine group is in the 4-position. A crystalline powder introduced medically in the late 19th century as Atoxyl, its sodium salt was used by injection in the early 20th century as the first organic arsenical drug, but it was soon found prohibitively toxic for human use. Arsanilic acid saw long use as a veterinary feed additive promoting growth and to prevent or treat dysentery in poultry and swine. In 2013, its approval by US government as an animal drug was voluntarily withdrawn by its sponsors. Still sometimes used in laboratories, arsanilic acid's legacy is principally through its influence on Paul Ehrlich in launching the antimicrobial chemotherapy approach to treating infectious diseases of humans. Chemistry Synthesis was first reported in 1863 by Antoine Béchamp and became the basis of the Bechamp reaction. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zwitterion
In chemistry, a zwitterion ( ; ), also called an inner salt or dipolar ion, is a molecule that contains an equal number of positively- and negatively-charged functional groups. : With amino acids, for example, in solution a chemical equilibrium will be established between the "parent" molecule and the zwitterion. Betaines are zwitterions that cannot isomerize to an all-neutral form, such as when the positive charge is located on a quaternary ammonium group. Similarly, a molecule containing a phosphonium group and a carboxylate group cannot isomerize. Amino acids The equilibrium is established in two stages. In the first stage, a proton is transferred from the carboxyl group to a water molecule: :H2N(R)CO2H + H2O H2N(R)CO2- + H3O+ In the second stage, a proton is transferred from the hydronium ion to the amine group: :H2N(R)CO2- + H3O+ H3N+ (R)CO2- + H2O Overall, the reaction is an isomerization reaction :H2N(R)CO2H H3N+ (R)CO2- The ratio of the concentrations of the two spec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrophilic Aromatic Substitution
Electrophilic aromatic substitution is an organic reaction in which an atom that is attached to an aromatic system (usually hydrogen) is replaced by an electrophile. Some of the most important electrophilic aromatic substitutions are aromatic nitration, aromatic halogenation, aromatic sulfonation, and alkylation and acylation Friedel–Crafts reaction. Illustrative reactions The most widely practised example of this reaction is the ethylation of benzene. :: Approximately 24,700,000 tons were produced in 1999. (After dehydrogenation and polymerization, the commodity plastic polystyrene is produced.) In this process, acids are used as catalyst to generate the incipient carbocation. Many other electrophilic reactions of benzene are conducted, although on a much smaller scale; they are valuable routes to key intermediates. The nitration of benzene is achieved via the action of the nitronium ion as the electrophile. The sulfonation with fuming sulfuric acid gives benzenesulfonic ac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Robert Koch
Heinrich Hermann Robert Koch ( , ; 11 December 1843 – 27 May 1910) was a German physician and microbiologist. As the discoverer of the specific causative agents of deadly infectious diseases including tuberculosis, cholera (though the Vibrio cholerae, bacterium itself was discovered by Filippo Pacini in 1854), and anthrax, he is regarded as one of the main founders of modern bacteriology. As such he is popularly nicknamed the father of microbiology (with Louis Pasteur), and as the father of medical bacteriology. His discovery of the anthrax bacterium (''Bacillus anthracis'') in 1876 is considered as the birth of modern bacteriology. His discoveries directly provided proofs for the germ theory of diseases, and the scientific basis of public health. While working as a private physician, Koch developed many innovative techniques in microbiology. He was the first to use the oil immersion lens, Condenser (optics), condenser, and microphotography in microscopy. His invention of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
World War I
World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, the United States, and the Ottoman Empire, with fighting occurring throughout Europe, the Middle East, Africa, the Pacific, and parts of Asia. An estimated 9 million soldiers were killed in combat, plus another 23 million wounded, while 5 million civilians died as a result of military action, hunger, and disease. Millions more died in genocides within the Ottoman Empire and in the 1918 influenza pandemic, which was exacerbated by the movement of combatants during the war. Prior to 1914, the European great powers were divided between the Triple Entente (comprising France, Russia, and Britain) and the Triple Alliance (containing Germany, Austria-Hungary, and Italy). Tensions in the Balkans came to a head on 28 June 1914, following the assassination of Archduke Franz Ferdin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bayer
Bayer AG (, commonly pronounced ; ) is a German multinational corporation, multinational pharmaceutical and biotechnology company and one of the largest pharmaceutical companies in the world. Headquartered in Leverkusen, Bayer's areas of business include pharmaceuticals; consumer healthcare products, agricultural chemicals, seeds and biotechnology products. The company is a component of the Euro Stoxx 50 stock market index. Bayer was founded in 1863 in Barmen as a partnership between dye salesman Friedrich Bayer and dyer Friedrich Weskott. As was common in this era, the company was established as a dyestuffs producer. The versatility of aniline chemistry led Bayer to expand their business into other areas, and in 1899 Bayer launched the compound acetylsalicylic acid under the trademarked name Aspirin. In 1904 Bayer received a trademark for the "Bayer Cross" logo, which was subsequently stamped onto each aspirin tablet, creating an iconic product that is still sold by Bayer. Ot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stanford University Press
Stanford University Press (SUP) is the publishing house of Stanford University. It is one of the oldest academic presses in the United States and the first university press to be established on the West Coast. It was among the presses officially admitted to the Association of American University Presses (now the Association of University Presses) at the organization's founding, in 1937, and is one of twenty-two current member presses from that original group. The press publishes 130 books per year across the humanities, social sciences, and business, and has more than 3,500 titles in print. History David Starr Jordan, the first president of Stanford University, posited four propositions to Leland and Jane Stanford when accepting the post, the last of which stipulated, “That provision be made for the publication of the results of any important research on the part of professors, or advanced students. Such papers may be issued from time to time as ‘Memoirs of the Leland Stanf ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Colonial Medicine
Colonial or The Colonial may refer to: * Colonial, of, relating to, or characteristic of a colony or colony (biology) Architecture * American colonial architecture * French Colonial * Spanish Colonial architecture Automobiles * Colonial (1920 automobile), the first American automobile with four-wheel brakes * Colonial (Shaw automobile), a rebranded Shaw sold from 1921 until 1922 * Colonial (1921 automobile), a car from Boston which was sold from 1921 until 1922 Places * The Colonial (Indianapolis, Indiana) * The Colonial (Mansfield, Ohio), a National Register of Historic Places listing in Richland County, Ohio * Ciudad Colonial (Santo Domingo), a historic central neighborhood of Santo Domingo * Colonial Country Club (Memphis), a golf course in Tennessee * Colonial Country Club (Fort Worth), a golf course in Texas ** Fort Worth Invitational or The Colonial, a PGA golf tournament Trains * ''Colonial'' (PRR train), a Pennsylvania Railroad run between Washington, DC and New York C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Socioeconomic
Socioeconomics (also known as social economics) is the social science that studies how economic activity affects and is shaped by social processes. In general it analyzes how modern societies progress, stagnate, or regress because of their local or regional economy, or the global economy. Overview “Socioeconomics” is sometimes used as an umbrella term for various areas of inquiry. The term “social economics” may refer broadly to the "use of economics in the study of society". More narrowly, contemporary practice considers behavioral interactions of individuals and groups through social capital and social "markets" (not excluding, for example, sorting by marriage) and the formation of social norms. In the relation of economics to social values. A distinct supplemental usage describes social economics as "a discipline studying the reciprocal relationship between economic science on the one hand and social philosophy, ethics, and human dignity on the other" toward social ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
African Trypanosomiasis
African trypanosomiasis, also known as African sleeping sickness or simply sleeping sickness, is an insect-borne parasitic infection of humans and other animals. It is caused by the species ''Trypanosoma brucei''. Humans are infected by two types, ''Trypanosoma brucei gambiense'' (TbG) and '' Trypanosoma brucei rhodesiense'' (TbR). TbG causes over 98% of reported cases. Both are usually transmitted by the bite of an infected tsetse fly and are most common in rural areas. Initially, the first stage of the disease is characterized by fevers, headaches, itchiness, and joint pains, beginning one to three weeks after the bite. Weeks to months later, the second stage begins with confusion, poor coordination, numbness, and trouble sleeping. Diagnosis is by finding the parasite in a blood smear or in the fluid of a lymph node. A lumbar puncture is often needed to tell the difference between first- and second-stage disease. If the disease is not treated quickly it can lead to death. P ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trypanosomiasis
Trypanosomiasis or trypanosomosis is the name of several diseases in vertebrates caused by parasitic protozoan trypanosomes of the genus ''Trypanosoma''. In humans this includes African trypanosomiasis and Chagas disease. A number of other diseases occur in other animals. African trypanosomiasis, which is caused by either ''Trypanosoma brucei gambiense'' or ''Trypanosoma brucei rhodesiense'', threatens some 65 million people in sub-Saharan Africa, especially in rural areas and populations disrupted by war or poverty. The number of cases has been going down due to systematic eradication efforts: in 1998 almost 40,000 cases were reported but almost 300,000 cases were suspected to have occurred; in 2009, the number dropped below 10,000; and in 2018 it dropped below 1000. Chagas disease causes 21,000 deaths per year mainly in Latin America. Signs and symptoms The tsetse fly bite erupts into a red chancre sore and within a few weeks, the person can experience fever, swollen lymph gla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aniline Dye
Aniline is an organic compound with the formula C6 H5 NH2. Consisting of a phenyl group attached to an amino group, aniline is the simplest aromatic amine. It is an industrially significant commodity chemical, as well as a versatile starting material for fine chemical synthesis. Its main use is in the manufacture of precursors to polyurethane, dyes, and other industrial chemicals. Like most volatile amines, it has the odor of rotten fish. It ignites readily, burning with a smoky flame characteristic of aromatic compounds. It is toxic to humans. Relative to benzene, it is electron-rich. It thus participates more rapidly in electrophilic aromatic substitution reactions. Likewise, it is also prone to oxidation: while freshly purified aniline is an almost colorless oil, exposure to air results in gradual darkening to yellow or red, due to the formation of strongly colored, oxidized impurities. Aniline can be diazotized to give a diazonium salt, which can then undergo various n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fowler's Solution
Fowler's solution is a solution containing 1% potassium arsenite (KAsO2), and was once prescribed as a remedy or a tonic. Thomas Fowler (1736–1801) of Stafford, England, proposed the solution in 1786 as a substitute for a patent medicine, "tasteless ague drop". From 1865, Fowler's solution was a leukemia treatment. From 1905, inorganic arsenicals like Fowler's solution saw diminished use as attention turned to organic arsenicals, starting with Atoxyl. As arsenical compounds are notably toxic and carcinogenic—with side effects such as cirrhosis of the liver, idiopathic portal hypertension, urinary bladder cancer, and skin cancers—Fowler's solution fell from use. (In 2001, however, the U.S. Food and Drug Administration (FDA) approved a drug of arsenic trioxide to treat acute promyelocytic leukaemia Acute promyelocytic leukemia (APML, APL) is a subtype of acute myeloid leukemia (AML), a cancer of the white blood cells. In APL, there is an abnormal accumulation of imma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
