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1922 In Science
The year 1922 in science and technology involved some significant events, listed below. Archaeology * November 4 – British archaeologist Howard Carter (archaeologist), Howard Carter and his men find the entrance to King Tutankhamen's tomb in the Valley of the Kings of Egypt. Biology * August – The California grizzly bear is hunted to extinction. * Last known wild Barbary lion (''P. l. leo'') shot in the Atlas Mountains of Morocco. * The Amur tiger becomes extinct in South Korea. * H. J. Muller sets out the basic properties of Genetics, genetic heredity. Chemistry * June 20 – Degesch applies to patent the cyanide-based insecticide Zyklon B (credited to Walter Heerdt) in Germany. * Vitamin E is discovered by Herbert McLean Evans and Katharine Scott Bishop at the University of California, Berkeley and Vitamin D by Elmer McCollum and others. * Czech people, Czech chemist Jaroslav Heyrovský invents polarography, polarographic methods of chemical analysis. * German chemist He ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyanide
In chemistry, cyanide () is an inorganic chemical compound that contains a functional group. This group, known as the cyano group, consists of a carbon atom triple-bonded to a nitrogen atom. Ionic cyanides contain the cyanide anion . This anion is extremely poisonous. Soluble cyanide salts such as sodium cyanide (NaCN), potassium cyanide (KCN) and tetraethylammonium cyanide () are highly toxic. Covalent cyanides contain the group, and are usually called nitriles if the group is linked by a single covalent bond to carbon atom. For example, in acetonitrile , the cyanide group is bonded to methyl . In tetracyanomethane , four cyano groups are bonded to carbon. Although nitriles generally do not release cyanide ions, the cyanohydrins do and are thus toxic. The cyano group may be covalently bonded to atoms different than carbon, e.g., in cyanogen azide , phosphorus tricyanide and trimethylsilyl cyanide . Hydrogen cyanide, or , is a highly volatile toxic liquid tha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Macromolecule
A macromolecule is a "molecule of high relative molecular mass, the structure of which essentially comprises the multiple repetition of units derived, actually or conceptually, from molecules of low relative molecular mass." Polymers are physical examples of macromolecules. Common macromolecules are biopolymers (nucleic acids, proteins, and carbohydrates). and polyolefins (polyethylene) and polyamides (nylon). Synthetic macromolecules Many macromolecules are synthetic polymers (plastics, synthetic fibers, and synthetic rubber. Polyethylene is produced on a particularly large scale such that ethylene is the primary product in the chemical industry. Macromolecules in nature * Proteins are polymers of amino acids joined by peptide bonds. * DNA and RNA are polymers of nucleotides joined by phosphodiester bonds. These nucleotides consist of a phosphate group, a sugar ( ribose in the case of RNA, deoxyribose in the case of DNA), and a nucleotide base (either adenine, guan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hermann Staudinger
Hermann Staudinger (; 23 March 1881 – 8 September 1965) was a German organic chemist who demonstrated the existence of macromolecules, which he characterized as polymers. For this work he received the 1953 Nobel Prize in Chemistry. He is also known for his discovery of ketenes and of the Staudinger reaction. Staudinger, together with Leopold Ružička, also elucidated the molecular structures of pyrethrin I and II in the 1920s, enabling the development of pyrethroid insecticides in the 1960s and 1970s. Early work Staudinger was born in 1881 in Worms. Staudinger, who initially wanted to become a botanist, studied chemistry at the University of Halle, at the TH Darmstadt and at the LMU Munich. He received his "Verbandsexamen" (comparable to Master's degree) from TH Darmstadt. After receiving his Ph.D. from the University of Halle in 1903, Staudinger qualified as an academic lecturer at the University of Strasbourg in 1907. He was supported in his work by his new wife Dora ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polarography
Polarography is a type of voltammetry where the working electrode is a dropping mercury electrode (DME) or a static mercury drop electrode (SMDE), which are useful for their wide cathodic ranges and renewable surfaces. It was invented in 1922 by Czechoslovakia, Czechoslovak chemist Jaroslav Heyrovský, for which he won the Nobel prize in 1959. The main advantages of mercury as electrode material are as follows: 1) a large voltage window: ca. from +0.2 V to -1.8 V vs reversible hydrogen electrode (RHE). Hg electrode is particularly well-suited for studying electroreduction reactions. 2) very reproducible electrode surface, since mercury is liquid. 3) very easy cleaning of the electrode surface by making a new drop of mercury from a large Hg pool connected by a glass capillary. Polarography played a major role as an experimental tool in the advancement of both Analytical Chemistry and Electrochemistry until the 1990s (see figure below), when it was supplanted by other methods that d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jaroslav Heyrovský
Jaroslav Heyrovský (; 20 December 1890 – 27 March 1967) was a Czech chemist and inventor who received the Nobel Prize in Chemistry in 1959 for his invention of polarography. Life and work Jaroslav Heyrovský was born in Prague on December 20, 1890, the fifth child of Leopold Heyrovský, Professor of Roman Law at the Charles University in Prague, and his wife Clara, née Hanl von Kirchtreu. He obtained his early education at secondary school until 1909 when he began his study of chemistry, physics, and mathematics at the Charles University in Prague. From 1910 to 1914 he continued his studies at University College London, under Professors Sir William Ramsay, W. C. McC. Lewis, and F. G. Donnan, taking his B.Sc. degree in 1913. He was particularly interested in working with Professor Donnan, on electrochemistry. During the First World War Heyrovský worked in a military hospital as a dispensing chemist and radiologist, which enabled him to continue his studies and to take hi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Czech People
The Czechs (, ; singular Czech, masculine: ''Čech'' , singular feminine: ''Češka'' ), or the Czech people (), are a West Slavic ethnic group and a nation native to the Czech Republic in Central Europe, who share a common ancestry, culture, history, and the Czech language. Ethnic Czechs were called Bohemians in English until the early 20th century, referring to the former name of their country, Bohemia, which in turn was adapted from the late Iron Age tribe of Celtic Boii. During the Migration Period, West Slavic tribes settled in the area, "assimilated the remaining Celtic and Germanic populations", and formed a principality in the 9th century, which was initially part of Great Moravia, in form of Duchy of Bohemia and later Kingdom of Bohemia, the predecessors of the modern republic. The Czech diaspora is found in notable numbers in the United States, Germany, Canada, Slovakia, Austria, the United Kingdom, Argentina, Australia, Switzerland, France, Russia, Italy, Is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elmer McCollum
Elmer Verner McCollum (March 3, 1879 – November 15, 1967) was an American biochemist known for his work on the influence of diet on health.Kruse, 1961. McCollum is also remembered for starting the first rat colony in the United States to be used for nutrition research. His reputation has suffered from posthumous controversy. ''Time'' magazine called him Dr.Vitamin. His rule was, "Eat what you want after you have eaten what you should." Living at a time when vitamins were unknown, he asked and tried to answer the questions, "How many dietary essentials are there, and what are they?" He and Marguerite Davis discovered the first vitamin, named A, in 1913. McCollum also helped to discover vitaminB and vitaminD and worked out the effect of trace elements in the diet. As a worker in Wisconsin and later at Johns Hopkins, McCollum acted partly at the request of the dairy industry. When he said that milk was "the greatest of all protective foods", milk consumption in the United Stat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vitamin D
Vitamin D is a group of structurally related, fat-soluble compounds responsible for increasing intestinal absorption of calcium, magnesium, and phosphate, along with numerous other biological functions. In humans, the most important compounds within this group are vitamin D3 ( cholecalciferol) and vitamin D2 ( ergocalciferol). Unlike the other twelve vitamins, vitamin D is only conditionally essential, as with adequate skin exposure to the ultraviolet B (UVB) radiation component of sunlight there is synthesis of cholecalciferol in the lower layers of the skin's epidermis. For most people, skin synthesis contributes more than diet sources. Vitamin D can also be obtained through diet, food fortification and dietary supplements. In the U.S., cow's milk and plant-based milk substitutes are fortified with vitamin D3, as are many breakfast cereals. Government dietary recommendations typically assume that all of a person's vitamin D is taken by mouth, given the potential for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Science (journal)
''Science'' is the peer review, peer-reviewed academic journal of the American Association for the Advancement of Science (AAAS) and one of the world's top academic journals. It was first published in 1880, is currently circulated weekly and has a subscriber base of around 130,000. Because institutional subscriptions and online access serve a larger audience, its estimated readership is over 400,000 people. ''Science'' is based in Washington, D.C., United States, with a second office in Cambridge, UK. Contents The major focus of the journal is publishing important original scientific research and research reviews, but ''Science'' also publishes science-related news, opinions on science policy and other matters of interest to scientists and others who are concerned with the wide implications of science and technology. Unlike most scientific journals, which focus on a specific field, ''Science'' and its rival ''Nature (journal), Nature'' cover the full range of List of academ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of California, Berkeley
The University of California, Berkeley (UC Berkeley, Berkeley, Cal, or California), is a Public university, public Land-grant university, land-grant research university in Berkeley, California, United States. Founded in 1868 and named after the Anglo-Irish philosopher George Berkeley, it is the state's first land-grant university and is the founding campus of the University of California system. Berkeley has an enrollment of more than 45,000 students. The university is organized around fifteen schools of study on the same campus, including the UC Berkeley College of Chemistry, College of Chemistry, the UC Berkeley College of Engineering, College of Engineering, UC Berkeley College of Letters and Science, College of Letters and Science, and the Haas School of Business. It is Carnegie Classification of Institutions of Higher Education, classified among "R1: Doctoral Universities – Very high research activity". Lawrence Berkeley National Laboratory was originally founded as par ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Herbert McLean Evans
Herbert McLean Evans (September 23, 1882 – March 6, 1971) was an American anatomist and embryologist best known for co-discovering Vitamin E. Education He was born in Modesto, California. In 1908, he obtained his medical degree from Johns Hopkins University. Career Evans became associate professor of anatomy at Johns Hopkins University. Evans moved back to California in 1915 and was made professor of anatomy at the University of California, Berkeley, and held that position until his death. His medical research at Berkeley addressed problems relating to human nutrition, endocrinology, embryology, and histology. In 1918, his research into the number of human chromosomes led him to believe the number to be 48, when most people assumed the number to be much higher. It was only later discovered that the correct figure was 46. Evans had much greater success however with hormones extracted from the anterior lobe of the pituitary gland. He isolated Human Growth Hormone, which is esse ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
