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Mutagenicity
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 Renaissance, 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 17th century. Paracelsianism is the early modern medical movement inspired by the study of his works. Biography Paracelsus was born in Einsiedeln, a village close to the Etzel Pass in Einsiedeln, canton of Schwyz, Schwyz. He was born in a house next to a bridge across the Sihl river. His father Wilhelm (d. 1534) was a chemist and physician, an illegitimate descendant of the Duchy of Swabia, S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ionizing Radiation
Ionizing (ionising) radiation, including Radioactive decay, nuclear radiation, consists of subatomic particles or electromagnetic waves that have enough energy per individual photon or particle to ionization, 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 vacuum ultraviolet, ultraviolet part of the electromagnetic spectrum are ionizing radiation; whereas the lower energy ultraviolet, visible light, infrared, microwaves, and radio waves are non-ionizing radiation. Nearly all types of laser light are non-ionizing radiation. The boundary between ionizing and non-ionizing radiation in the ultraviolet area cannot be sharply defined, as different molecules and atoms ionize at Ionization energies of the elements (data page), different energies. The energy of ionizing radiation starts ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Georgii Nadson
Georgii Adamovich Nadson ( – 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, 1939, 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 ( , ; : alga ) is an informal term for any organisms of a large and diverse group of ph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Henri Becquerel
Antoine Henri Becquerel ( ; ; 15 December 1852 – 25 August 1908) was a French nuclear physicist who shared the 1903 Nobel Prize in Physics with Marie and Pierre Curie for his discovery of radioactivity. Biography Family and education Becquerel was born in Paris, France, into a wealthy family which produced four generations of notable physicists, including Becquerel's grandfather ( Antoine César Becquerel), father ( 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. Career Becquerel's earliest works centered on the subject of his doctoral thesis: the plane polarization of light, with the phenomenon of phosphorescence and absorption of light by crystals. Becquerel was awarded a Doctor of Science in 1888. Early in his career, Becquerel also studied the Earth's magnetic field. Becqu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wilhelm Röntgen
Wilhelm Conrad Röntgen (; 27 March 1845 – 10 February 1923), sometimes Transliteration, transliterated as Roentgen ( ), was a German physicist who produced and detected electromagnetic radiation in a wavelength range known as X-rays. As a result of this discovery, he became the first recipient of the Nobel Prize in Physics in 1901.Novelize, Robert. ''Squire's Fundamentals of Radiology''. Harvard University Press. 5th ed. 1997. p. 1. Biographical history Education Röntgen was born in Lennep on 27 March 1845 to Friedrich Conrad Röntgen, a German merchant and cloth manufacturer, and Charlotte Constanze Frowein. When he was aged three, his family moved to the Netherlands, where his mother's family lived, rendering him Statelessness, stateless. He attended high school at Utrecht Technical School in Utrecht, Netherlands. He followed courses at the Technical School for almost two years. In 1865, he was unfairly expelled from high school when one of his teachers intercepted a ... [...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 * ' ... [...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 ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polycyclic Aromatic Hydrocarbon
A Polycyclic aromatic hydrocarbon (PAH) is any member of a class of organic compounds that is composed of multiple fused aromatic rings. Most are produced by the incomplete combustion of organic matter— by engine exhaust fumes, tobacco, incinerators, in roasted meats and cereals, or when biomass burns at lower temperatures as in forest fires. 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 also found in fossil fuel deposits such as coal and in petroleum. Exposure to PAHs can lead to different types of cancer, to fetal development complications, and to cardiovascular issues. 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 hydro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Soot
Soot ( ) is a mass of impure carbon particles resulting from the incomplete combustion of hydrocarbons. Soot is considered a hazardous substance with carcinogenic properties. Most broadly, the term includes all the particulate matter produced by this process, including black carbon and residual pyrolysed fuel particles such as coal, cenospheres, charred wood, and petroleum coke classified as cokes or char. It can include polycyclic aromatic hydrocarbons and heavy metals like mercury. Soot causes various types of cancer and lung disease. Terminology Definition Among scientists, exact definitions for soot vary, depending partly on their field. For example, atmospheric scientists may use a different definition compared to toxicologists. Soot's definition can also vary across time, and from paper to paper even among scientists in the same field. A common feature of the definitions is that soot is composed largely of carbon based particles resulting from the incomplete burni ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chimney Sweep
A chimney sweep is a person who inspects then 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 ordinance w ... [...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 cancer may be caused by an environmental carcinogen, namely chimney sweeps' carcinoma. Many diseases are his namesake including Pott's fracture, Pott's disease of the spine, and Pott's puffy tumour. It is believed that Pott's standard of living contributed to the rise of the surgeon within social standings. Early life and education Percivall Pott was born the son of Percivall Pott senior in London. 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. Career He became assistant surgeon to St Bartholomew's in 1744 and full surgeon from 1749 till 1787. As t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
