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Antimutagenic Agents
In genetics, a mutagen is a physical or chemical agent that permanently changes genetic material, usually DNA, in an organism and thus increases the frequency of mutations above the natural background level. As many mutations can cause cancer in animals, such mutagens can therefore be carcinogens, although not all necessarily are. All mutagens have characteristic mutational signatures with some chemicals becoming mutagenic through cellular processes. The process of DNA becoming modified is called mutagenesis. Not all mutations are caused by mutagens: so-called "spontaneous mutations" occur due to spontaneous hydrolysis, errors in DNA replication, repair and recombination. Discovery The first mutagens to be identified were carcinogens, substances that were shown to be linked to cancer. Tumors were described more than 2,000 years before the discovery of chromosomes and DNA; in 500 B.C., the Greek physician Hippocrates named tumors resembling a crab ''karkinos'' (from which the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paracelsus
Paracelsus (; ; 1493 – 24 September 1541), born Theophrastus von Hohenheim (full name Philippus Aureolus Theophrastus Bombastus von Hohenheim), was a Swiss physician, alchemist, lay theologian, and philosopher of the German Renaissance. He was a pioneer in several aspects of the " medical revolution" of the Renaissance, emphasizing the value of observation in combination with received wisdom. He is credited as the "father of toxicology". Paracelsus also had a substantial influence as a prophet or diviner, his "Prognostications" being studied by Rosicrucians in the 1600s. Paracelsianism is the early modern medical movement inspired by the study of his works. Biography Paracelsus was born in Egg an der Sihl, a village close to the Etzel Pass in Einsiedeln, Schwyz. He was born in a house right next to a bridge across the Sihl river (known as ''Teufelsbrücke''). The historical house, dated to the 14th century, was destroyed in 1814. The ''Restaurant Krone'' now stands in its pl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ionizing Radiation
Ionizing radiation (or ionising radiation), including nuclear radiation, consists of subatomic particles or electromagnetic waves that have sufficient energy to ionize atoms or molecules by detaching electrons from them. Some particles can travel up to 99% of the speed of light, and the electromagnetic waves are on the high-energy portion of the electromagnetic spectrum. Gamma rays, X-rays, and the higher energy ultraviolet part of the electromagnetic spectrum are ionizing radiation, whereas the lower energy ultraviolet, visible light, nearly all types of laser light, infrared, microwaves, and radio waves are non-ionizing radiation. The boundary between ionizing and non-ionizing radiation in the ultraviolet area is not sharply defined, as different molecules and atoms ionize at different energies. The energy of ionizing radiation starts between 10 electronvolts (eV) and 33 eV. Typical ionizing subatomic particles include alpha particles, beta particles, and neutrons. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Georgii Nadson
Georgii Adamovich Nadson (, Kiev – April 15, 1939) was a Soviet biologist, "one of the pioneers of radioecology in Russia"D. I. NikitinSoil Microbiology at the Institute of Microbiology.Russian Academy of Sciences He became professor at St. Petersburg University in 1900. In 1930, he founded the Laboratory of Microbiology of the Russian Academy of Sciences (which in 1934 was transferred from Leningrad to Moscow and later transformed into the Institute of Microbiology). He was director of the institute until 1937, when he was "falsely accused of participating in so-called anti-Soviet sabotage and terrorism and arrested" On April 14, 1930, he was found guilty of participation in a terrorist organization, and on the next day he was shot and buried at the Kommunarka shooting ground. The real reason for his execution was his opposition to Lysenkoism. '' Ulvella nadsonii'', a species of algae Algae (; singular alga ) is an informal term for a large and diverse group of photosyntheti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Henri Becquerel
Antoine Henri Becquerel (; 15 December 1852 – 25 August 1908) was a French engineer, physicist, Nobel laureate, and the first person to discover evidence of radioactivity. For work in this field he, along with Marie Skłodowska-Curie and Pierre Curie, received the 1903 Nobel Prize in Physics. The SI unit for radioactivity, the becquerel (Bq), is named after him. Biography Early life Becquerel was born in Paris, France, into a wealthy family which produced four generations of physicists: Becquerel's grandfather (Antoine César Becquerel), father ( Alexandre-Edmond Becquerel), and son (Jean Becquerel). Henri started off his education by attending the Lycée Louis-le-Grand school, a prep school in Paris. He studied engineering at the École Polytechnique and the École des Ponts et Chaussées. In 1874, Henri married Lucie Zoé Marie Jamin, who would die while giving birth to their son, Jean. In 1890 he married Louise Désirée Lorieux. Career In Becquerel's early career, he ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wilhelm Röntgen
Wilhelm Conrad Röntgen (; ; 27 March 184510 February 1923) was a German mechanical engineer and physicist, who, on 8 November 1895, produced and detected electromagnetic radiation in a wavelength range known as X-rays or Röntgen rays, an achievement that earned him the inaugural Nobel Prize in Physics in 1901.Novelize, Robert. ''Squire's Fundamentals of Radiology''. Harvard University Press. 5th edition. 1997. p. 1. In honour of Röntgen's accomplishments, in 2004 the International Union of Pure and Applied Chemistry (IUPAC) named element 111, roentgenium, a radioactive element with multiple unstable isotopes, after him. The unit of measurement roentgen was also named after him. Biographical history Education He was born to Friedrich Conrad Röntgen, a German merchant and cloth manufacturer, and Charlotte Constanze Frowein. At age three his family moved to the Netherlands where his family lived. Röntgen attended high school at Utrecht Technical School in Utrecht, Netherland ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Journal Of The Chemical Society
The ''Journal of the Chemical Society'' was a scientific journal established by the Chemical Society in 1849 as the ''Quarterly Journal of the Chemical Society''. The first editor was Edmund Ronalds. The journal underwent several renamings, splits, and mergers throughout its history. In 1980, the Chemical Society merged with several other organizations into the Royal Society of Chemistry. The journal's continuity is found in ''Chemical Communications'', ''Dalton Transactions'', ''Faraday Transactions'', and ''Perkin Transactions'', all of which are published by the Royal Society of Chemistry. History ;'' Proceedings of the Chemical Society'' * ''Memoirs of the Chemical Society of London'' (1841) * ''Proceedings of the Chemical Society of London'' (1842–1843) * ''Memoirs and Proceedings of the Chemical Society'' (1843–1848) * ''Proceedings of the Chemical Society, London'' (1885–1914) * Published as a supplement to ''Journal of the Chemical Society'' from 1914 to 1956 * ''Proc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Benzo(a)pyrene
Benzo 'a''yrene (B''a''P or B ) is a polycyclic aromatic hydrocarbon and the result of incomplete combustion of organic matter at temperatures between and . The ubiquitous compound can be found in coal tar, tobacco smoke and many foods, especially grilled meats. The substance with the formula C20H12 is one of the benzopyrenes, formed by a benzene ring fused to pyrene. Its diol epoxide metabolites (more commonly known as BPDE) react with and bind to DNA, resulting in mutations and eventually cancer. It is listed as a Group 1 carcinogen by the IARC. In the 18th century a scrotal cancer of chimney sweepers, the chimney sweeps' carcinoma, was already known to be connected to soot. Description Benzo 'a''yrene (B''a''P) is a polycyclic aromatic hydrocarbon found in coal tar with the formula C20H12. The compound is one of the benzopyrenes, formed by a benzene ring fused to pyrene, and is the result of incomplete combustion at temperatures between and . Sources The main source ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polycyclic Aromatic Hydrocarbon
A polycyclic aromatic hydrocarbon (PAH) is a class of organic compounds that is composed of multiple aromatic rings. The simplest representative is naphthalene, having two aromatic rings and the three-ring compounds anthracene and phenanthrene. PAHs are uncharged, non-polar and planar. Many are colorless. Many of them are found in coal and in oil deposits, and are also produced by the combustion of organic matter—for example, in engines and incinerators or when biomass burns in forest fires. Polycyclic aromatic hydrocarbons are discussed as possible starting materials for abiotic syntheses of materials required by the earliest forms of life. Nomenclature and structure The terms polyaromatic hydrocarbon or polynuclear aromatic hydrocarbon are also used for this concept. By definition, polycyclic aromatic hydrocarbons have multiple rings, precluding benzene from being considered a PAH. Some sources, such as the US EPA and CDC, consider naphthalene to be the simplest PAH. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Soot
Soot ( ) is a mass of impure carbon particles resulting from the incomplete combustion of hydrocarbons. It is more properly restricted to the product of the gas-phase combustion process but is commonly extended to include the residual pyrolysed fuel particles such as coal, cenospheres, charred wood, and petroleum coke that may become airborne during pyrolysis and that are more properly identified as cokes or char. Soot causes various types of cancer and lung disease. Sources Soot as an airborne contaminant in the environment has many different sources, all of which are results of some form of pyrolysis. They include soot from coal burning, internal-combustion engines, power-plant boilers, hog-fuel boilers, ship boilers, central steam-heat boilers, waste incineration, local field burning, house fires, forest fires, fireplaces, and furnaces. These exterior sources also contribute to the indoor environment sources such as smoking of plant matter, cooking, oil lamps, candles, qu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chimney Sweep
A chimney sweep is a person who clears soot and creosote from chimneys. The chimney uses the pressure difference caused by a hot column of gas to create a draught and draw air over the hot coals or wood enabling continued combustion. Chimneys may be straight or contain many changes of direction. During normal operation, a layer of creosote builds up on the inside of the chimney, restricting the flow. The creosote can also catch fire, setting the chimney (and potentially the entire building) alight. The chimney must be swept to remove the soot. In Great Britain, master sweeps took apprentices, typically workhouse or orphan boys, and trained them to climb chimneys. In the German States, master sweeps belonged to trade guilds and did not use climbing boys. In Italy, Belgium, and France climbing boys were used. The occupation requires some dexterity, and carries health risks. History The Tudors in England had established the risk of chimneys and an ordnance was created in 1582 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Percivall Pott
Percivall Pott (6 January 1714, in London – 22 December 1788) was an English surgeon, one of the founders of orthopaedics, and the first scientist to demonstrate that a cancer may be caused by an environmental carcinogen. Career He was the son of Percivall Pott senior. His father died when he was a child, but Joseph Wilcocks, Bishop of Rochester, who was a relative of his mother, paid for his education. He served his apprenticeship with Edward Nourse, assistant surgeon to St Bartholomew's Hospital, and in 1736 was admitted to the Barbers' Company and licensed to practice. He became assistant surgeon to St Bartholomew's in 1744 and full surgeon from 1749 till 1787. As the first surgeon of his day in England, excelling even his pupil, John Hunter, on the practical side, Pott introduced various important innovations in procedure, doing much to abolish the extensive use of escharotics and the cautery that was prevalent when he began his career. In 1756, Pott sustained a bro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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