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Tobacco Mosaic Disease
''Tobacco mosaic virus'' (TMV) is a positive-sense single-stranded RNA virus species in the genus ''Tobamovirus'' that infects a wide range of plants, especially tobacco and other members of the family Solanaceae. The infection causes characteristic patterns, such as "mosaic"-like mottling and discoloration on the leaves (hence the name). TMV was the first virus to be discovered. Although it was known from the late 19th century that a non-bacterial infectious disease was damaging tobacco crops, it was not until 1930 that the infectious agent was determined to be a virus. It is the first pathogen identified as a virus. The virus was crystallised by W.M. Stanley. It has a similar size to the largest synthetic molecule, known as PG5 History In 1886, Adolf Mayer first described the tobacco mosaic disease that could be transferred between plants, similar to bacterial infections. In 1892, Dmitri Ivanovsky gave the first concrete evidence for the existence of a non-bacterial infecti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transmission Electron Micrograph
Transmission electron microscopy (TEM) is a microscopy technique in which a beam of electrons is transmitted through a specimen to form an image. The specimen is most often an ultrathin section less than 100 nm thick or a suspension on a grid. An image is formed from the interaction of the electrons with the sample as the beam is transmitted through the specimen. The image is then magnified and focused onto an imaging device, such as a fluorescent screen, a layer of photographic film, or a sensor such as a scintillator attached to a charge-coupled device. Transmission electron microscopes are capable of imaging at a significantly higher resolution than light microscopes, owing to the smaller de Broglie wavelength of electrons. This enables the instrument to capture fine detail—even as small as a single column of atoms, which is thousands of times smaller than a resolvable object seen in a light microscope. Transmission electron microscopy is a major analytical method i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dmitri Ivanovsky
Dmitri Iosifovich Ivanovsky (alternative spelling ''Dmitrii'' or ''Dmitry Iwanowski''; russian: Дми́трий Ио́сифович Ивано́вский; 28 October 1864 – 20 June 1920) was a Russian botanist, the co-discoverer of :viruses (1892) and one of the founders of virology. Life Ivanovsky was born in the village of Nizy, Gdov Uyezd. He studied at the University of Saint Petersburg under Andrei Famintsyn in 1887, when he was sent to Ukraine and Bessarabia to investigate a tobacco disease causing great damage to plantations located there at the time. Three years later, he was assigned to look into a similar disease occurrence of tobacco plants, this time raging in the Crimea region. He discovered that both incidents of disease were caused by an extremely minuscule infectious agent, capable of permeating porcelain Chamberland filters, something which bacteria could never do. He described his findings in an article (1892) and a dissertation (1902). Then he worked at t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
X-ray Crystallography
X-ray crystallography is the experimental science determining the atomic and molecular structure of a crystal, in which the crystalline structure causes a beam of incident X-rays to diffract into many specific directions. By measuring the angles and intensities of these diffracted beams, a crystallographer can produce a three-dimensional picture of the density of electrons within the crystal. From this electron density, the mean positions of the atoms in the crystal can be determined, as well as their chemical bonds, their crystallographic disorder, and various other information. Since many materials can form crystals—such as salts, metals, minerals, semiconductors, as well as various inorganic, organic, and biological molecules—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 among various mat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Capsid
A capsid is the protein shell of a virus, enclosing its genetic material. It consists of several oligomeric (repeating) structural subunits made of protein called protomers. The observable 3-dimensional morphological subunits, which may or may not correspond to individual proteins, are called capsomeres. The proteins making up the capsid are called capsid proteins or viral coat proteins (VCP). The capsid and inner genome is called the nucleocapsid. Capsids are broadly classified according to their structure. The majority of the viruses have capsids with either helical or icosahedral structure. Some viruses, such as bacteriophages, have developed more complicated structures due to constraints of elasticity and electrostatics. The icosahedral shape, which has 20 equilateral triangular faces, approximates a sphere, while the helical shape resembles the shape of a spring, taking the space of a cylinder but not being a cylinder itself. The capsid faces may consist of one or more ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Robley Williams
Robley Cook Williams (October 13, 1908 – January 3, 1995) was an early biophysicist and virologist. He served as the first president of the Biophysical Society. Career Williams attended Cornell University on an athletic scholarship, completing a B.S. in 1931 and a Ph.D. in physics in 1935. While at Cornell, he was selected for membership in the Telluride House and the Quill and Dagger society. Williams began his career as a researcher as an assistant professor of astronomy at the University of Michigan, and from 1945, associate professor of physics. A growing fascination with viruses led him to leave Michigan in 1950, when he was invited to the University of California, Berkeley by Wendell Stanley, to serve as a professor at the newly created Department of Virology. Research Together with Heinz Fraenkel-Conrat, Williams studied the Tobacco mosaic virus, and showed that a functional virus could be created out of purified RNA and a protein coat. That same year, he was elected t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heinz Fraenkel-Conrat
Heinz Ludwig Fraenkel-Conrat (July 29, 1910 – April 10, 1999) was a biochemist, famous for his research on viruses. Early life Fraenkel-Conrat was born in Breslau/Germany. He was the son of Lili Conrat and Professor Ludwig Fraenkel, director of the Women's Clinic of the University of Breslau, Germany. His father, Ludwig Fraenkel, was a prominent gynecologist and medical researcher who published regarding endocrine function, social gynecology, and sexology during the first decades of the 20th century, and was one of the legion of scientists summarily dismissed from their positions by the Nazis. Academic career He received an MD from the University of Breslau in 1933. Due to the rise of Nazism in Germany he left for Scotland in 1933 and finished his PhD at the University of Edinburgh (1936). After completing his doctorate, he emigrated to the United States, becoming a naturalized citizen in 1941. In the 1940s Fraenkel-Conrat visited his sister and brother-in-law, biochemist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ernst Ruska
Ernst August Friedrich Ruska (; 25 December 1906 – 27 May 1988) was a German physicist who won the Nobel Prize in Physics in 1986 for his work in electron optics, including the design of the first electron microscope. Life and career Ernst Ruska was born in Heidelberg, Germany. He was educated at the Technical University of Munich from 1925 to 1927 and then entered the Technical University of Berlin, where he posited that microscopes using electrons, with wavelengths 1000 times shorter than those of light, could provide a more detailed picture of an object than a microscope utilizing light, in which magnification is limited by the size of the wavelengths. In 1931, he demonstrated that a magnetic coil could act as an electron lens, and used several coils in a series to build the first electron microscope in 1933. After completing his PhD in 1933, Ruska continued to work in the field of electron optics, first at Fernseh AG in Berlin-Zehlendorf, and then from 1937 at Siemens ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Helmut Ruska
Helmut Ruska (June 7, 1908, Heidelberg - August 30, 1973) was a German physician and biologist from Heidelberg. After earning his medical degree, he spent several years working as a physician at hospitals in Heidelberg and Berlin. During this time, he also worked closely with his brother Ernst Ruska (1906-1988) and brother-in-law Bodo von Borries (1905-56), who were both research scientists at Siemens-Reiniger-Werke. Ernst Ruska was the inventor of the electron microscope, and later winner of a Nobel Prize. From 1948 to 1951, Helmut Ruska was a professor at the University of Berlin, in 1952 he moved to the United States where he was a micromorphologist for the New York State Department of Health in Albany. He returned to Germany in 1958 as director of biophysics at the University of Düsseldorf. Through close association with his brother, Helmut Ruska is remembered for developing the electron microscope for biological and medical applications. He was the first scientist to study " ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Edgar Pfankuch
Edgar is a commonly used English given name, from an Anglo-Saxon name ''Eadgar'' (composed of '' ead'' "rich, prosperous" and ''gar'' "spear"). Like most Anglo-Saxon names, it fell out of use by the later medieval period; it was, however, revived in the 18th century, and was popularised by its use for a character in Sir Walter Scott's ''The Bride of Lammermoor'' (1819). People with the given name * Edgar the Peaceful (942–975), king of England * Edgar the Ætheling (c. 1051 – c. 1126), last member of the Anglo-Saxon royal house of England * Edgar of Scotland (1074–1107), king of Scotland * Edgar Angara, Filipino lawyer * Edgar Barrier, American actor * Edgar Baumann, Paraguayan javelin thrower * Edgar Bergen, American actor, radio performer, ventriloquist * Edgar Berlanga, American boxer * Edgar H. Brown, American mathematician * Edgar Buchanan, American actor * Edgar Rice Burroughs, American author, creator of ''Tarzan'' * Edgar Cantero, Spanish author in Catalan, Spa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gustav Kausche
Gustav, Gustaf or Gustave may refer to: *Gustav (name), a male given name of Old Swedish origin Art, entertainment, and media * ''Primeval'' (film), a 2007 American horror film * ''Gustav'' (film series), a Hungarian series of animated short cartoons * Gustav (''Zoids''), a transportation mecha in the ''Zoids'' fictional universe *Gustav, a character in ''Sesamstraße'' *Monsieur Gustav H., a leading character in ''The Grand Budapest Hotel'' Weapons *Carl Gustav recoilless rifle, dubbed "the Gustav" by US soldiers *Schwerer Gustav, 800-mm German siege cannon used during World War II Other uses *Gustav (pigeon), a pigeon of the RAF pigeon service in WWII *Gustave (crocodile), a large male Nile crocodile in Burundi *Gustave, South Dakota *Hurricane Gustav (other), a name used for several tropical cyclones and storms *Gustav, a streetwear clothing brand See also *Gustav of Sweden (other) *Gustav Adolf (other) *Gustave Eiffel (other) * * *Gustavo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Autocatalysis
A single chemical reaction is said to be autocatalytic if one of the reaction products is also a catalyst for the same or a coupled reaction.Steinfeld J.I., Francisco J.S. and Hase W.L. ''Chemical Kinetics and Dynamics'' (2nd ed., Prentice-Hall 1999) p.151-2 Such a reaction is called an autocatalytic reaction. A ''set'' of chemical reactions can be said to be "collectively autocatalytic" if a number of those reactions produce, as reaction products, catalysts for enough of the other reactions that the entire set of chemical reactions is self-sustaining given an input of energy and food molecules (see autocatalytic set). Chemical reactions A chemical reaction of two reactants and two products can be written as : \alpha A + \beta B \rightleftharpoons \sigma S + \tau T where the Greek letters are stoichiometric coefficients and the capital Latin letters represent chemical species. The chemical reaction proceeds in both the forward and reverse direction. This equation is easily g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nobel Prize In Chemistry
) , image = Nobel Prize.png , alt = A golden medallion with an embossed image of a bearded man facing left in profile. To the left of the man is the text "ALFR•" then "NOBEL", and on the right, the text (smaller) "NAT•" then "MDCCCXXXIII" above, followed by (smaller) "OB•" then "MDCCCXCVI" below. , awarded_for = Outstanding contributions in chemistry , presenter = Royal Swedish Academy of Sciences , location = Stockholm, Sweden , reward = 9 million SEK (2017) , year = 1901 , holder = Carolyn R. Bertozzi, Morten P. Meldal and Karl Barry Sharpless (2022) , most_awards = Frederick Sanger and Karl Barry Sharpless (2) , website nobelprize.org, previous = 2021 , year2=2022, main=2022, next=2023 The Nobel Prize in Chemistry is awarded annually by the Royal Swedish Academy of Sciences to scientists in the various fields of chemistry. It is one of the five Nobel Prizes established by the will of Alfred Nobel in 1895, awarded for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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