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Vibration Theory
The vibration theory of smell proposes that a molecule's smell character is due to its vibrational frequency in the infrared range. This controversial theory is an alternative to the more widely accepted docking theory of olfaction (formerly termed the shape theory of olfaction), which proposes that a molecule's smell character is due to a range of weak non-covalent interactions between its protein odorant receptor (found in the nasal epithelium), such as electrostatic and Van der Waals interactions as well as H-bonding, dipole attraction, pi-stacking, metal ion, Cation–pi interaction, and hydrophobic effects, in addition to the molecule's conformation. Introduction The current vibration theory has recently been called the "swipe card" model, in contrast with "lock and key" models based on shape theory. As proposed by Luca Turin, the odorant molecule must first fit in the receptor's binding site. Then it must have a vibrational energy mode compatible with the difference i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Olfaction
The sense of smell, or olfaction, is the special sense through which smells (or odors) are perceived. The sense of smell has many functions, including detecting desirable foods, hazards, and pheromones, and plays a role in taste. In humans, it occurs when an odor binds to a receptor within the nasal cavity, transmitting a signal through the olfactory system. Glomeruli aggregate signals from these receptors and transmit them to the olfactory bulb, where the sensory input will start to interact with parts of the brain responsible for smell identification, memory, and emotion. There are many different things which can interfere with a normal sense of smell, including damage to the nose or smell receptors, anosmia, upper respiratory infections, traumatic brain injury, and neurodegenerative disease. History of study Early scientific study of the sense of smell includes the extensive doctoral dissertation of Eleanor Gamble, published in 1898, which compared olfactory to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Signal Transduction
Signal transduction is the process by which a chemical or physical signal is transmitted through a cell as a biochemical cascade, series of molecular events. Proteins responsible for detecting stimuli are generally termed receptor (biology), receptors, although in some cases the term sensor is used. The changes elicited by ligand (biochemistry), ligand binding (or signal sensing) in a receptor give rise to a biochemical cascade, which is a chain of biochemical events known as a Cell signaling#Signaling pathways, signaling pathway. When signaling pathways interact with one another they form networks, which allow cellular responses to be coordinated, often by combinatorial signaling events. At the molecular level, such responses include changes in the transcription (biology), transcription or translation (biology), translation of genes, and post-translational modification, post-translational and conformational changes in proteins, as well as changes in their location. These molecula ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deuterium
Deuterium (hydrogen-2, symbol H or D, also known as heavy hydrogen) is one of two stable isotopes of hydrogen; the other is protium, or hydrogen-1, H. The deuterium nucleus (deuteron) contains one proton and one neutron, whereas the far more common H has no neutrons. The name ''deuterium'' comes from Greek '' deuteros'', meaning "second". American chemist Harold Urey discovered deuterium in 1931. Urey and others produced samples of heavy water in which the H had been highly concentrated. The discovery of deuterium won Urey a Nobel Prize in 1934. Nearly all deuterium found in nature was synthesized in the Big Bang 13.8 billion years ago, forming the primordial ratio of H to H (~26 deuterium nuclei per 10 hydrogen nuclei). Deuterium is subsequently produced by the slow stellar proton–proton chain, but rapidly destroyed by exothermic fusion reactions. The deuterium–deuterium reaction has the second-lowest energy threshold, and is the most astrophysically acce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isotope
Isotopes are distinct nuclear species (or ''nuclides'') of the same chemical element. They have the same atomic number (number of protons in their Atomic nucleus, nuclei) and position in the periodic table (and hence belong to the same chemical element), but different nucleon numbers (mass numbers) due to different numbers of neutrons in their nuclei. While all isotopes of a given element have similar chemical properties, they have different atomic masses and physical properties. The term isotope is derived from the Greek roots isos (wikt:ἴσος, ἴσος "equal") and topos (wikt:τόπος, τόπος "place"), meaning "the same place"; thus, the meaning behind the name is that different isotopes of a single element occupy the same position on the periodic table. It was coined by Scottish doctor and writer Margaret Todd (doctor), Margaret Todd in a 1913 suggestion to the British chemist Frederick Soddy, who popularized the term. The number of protons within the atomic nuc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alexander Fleming Biomedical Sciences Research Center
The Biomedical Sciences Research Center "Alexander Fleming" (BSRC Al. Fleming, Greek: Ερευνητικό Κέντρο Βιοϊατρικών Επιστημών "Αλέξανδρος Φλέμινγκ") is a governmental, non-profit research organisation based in Vari, Athens, Greece. The Center is named after the scientist Alexander Fleming and his widow, Amalia Fleming "created the conditions to set up" this Center. History In 1965, microbiologist Amalia Fleming established the Hellenic Foundation for Basic Biological Research "Alexander Fleming", which she named in memory of her husband and fellow scientist Alexander Fleming. The next year in 1966, the Church granted to the foundation 128000 square meters of land in Vari, a suburb of Athens. Construction started in 1968, however it was interrupted in 1971 after the arrest of Amalia Fleming for actions against the military junta. Construction then resumed in 1975 and ended in 1993, thirteen years after Amalia's death. A 6000 sq ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PNAS
''Proceedings of the National Academy of Sciences of the United States of America'' (often abbreviated ''PNAS'' or ''PNAS USA'') is a peer-reviewed multidisciplinary scientific journal. It is the official journal of the National Academy of Sciences, published since 1915, and publishes original research, scientific reviews, commentaries, and letters. According to '' Journal Citation Reports'', the journal has a 2022 impact factor of 9.4. ''PNAS'' is the second most cited scientific journal, with more than 1.9 million cumulative citations from 2008 to 2018. In the past, ''PNAS'' has been described variously as "prestigious", "sedate", "renowned" and "high impact". ''PNAS'' is a delayed open-access journal, with an embargo period of six months that can be bypassed for an author fee ( hybrid open access). Since September 2017, open access articles are published under a Creative Commons license. Since January 2019, ''PNAS'' has been online-only, although print issues are avail ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Imperial College London
Imperial College London, also known as Imperial, is a Public university, public research university in London, England. Its history began with Prince Albert of Saxe-Coburg and Gotha, Prince Albert, husband of Queen Victoria, who envisioned a Albertopolis, cultural district in South Kensington that included museums, colleges, and the Royal Albert Hall. In 1907, these colleges – the Royal College of Science, the Royal School of Mines, and the City and Guilds of London Institute – merged to form the Imperial College of Science and Technology. In 1988, Imperial merged with St Mary's Hospital, London, St Mary's Hospital Medical School and then with Charing Cross and Westminster Medical School to form the Imperial College School of Medicine. The Imperial Business School was established in 2003 and officially opened by Elizabeth II, Queen Elizabeth II. Formerly a constituent college of the University of London, Imperial became an independent university in 2007. Imperial is o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University College London
University College London (Trade name, branded as UCL) is a Public university, public research university in London, England. It is a Member institutions of the University of London, member institution of the Federal university, federal University of London, and is the second-largest list of universities in the United Kingdom by enrolment, university in the United Kingdom by total enrolment and the largest by postgraduate enrolment. Established in 1826 as London University (though without university degree-awarding powers) by founders who were inspired by the radical ideas of Jeremy Bentham, UCL was the first university institution to be established in London, and the first in England to be entirely secular and to admit students regardless of their religion. It was also, in 1878, among the first university colleges to admit women alongside men, two years after University College, Bristol, had done so. Intended by its founders to be Third-oldest university in England debate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marshall Stoneham
Arthur Marshall Stoneham, FRS (18 May 1940 – 18 February 2011), known as Marshall Stoneham, was a British physicist who worked for the United Kingdom Atomic Energy Authority, and from 1995 was Massey professor of physics at University College London. Biography Stoneham was born in Barrow-in-Furness on 18 May 1940, son of Garth Rivers Stoneham, consultant obstetrician and gynaecologist, and fellow New Zealander Nancy Wooler (née Leslie). He was educated at Barrow Grammar School for Boys. He then read physics at the University of Bristol, where he graduated with a BSc in 1961, and a PhD, supervised by Maurice Pryce, in 1964. In 1964 he joined AERE Harwell, where he spent more than 30 years. After successive promotions he was made chief scientist of AEA Technology, an offshoot of AERE. But as the ability to conduct basic research diminished at Harwell in the 1990s Stoneham was drawn to UCL, where he was appointed Professor of Physics and Director of the Centre for Material ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Physical Review Letters
''Physical Review Letters'' (''PRL''), established in 1958, is a peer-reviewed, scientific journal that is published 52 times per year by the American Physical Society. The journal is considered one of the most prestigious in the field of physics. Over a quarter of Physics Nobel Prize-winning papers between 1995 and 2017 were published in it. ''PRL'' is published both online and as a print journal. Its focus is on short articles ("letters") intended for quick publication. The Lead Editor is Hugues Chaté. The Managing Editor is Robert Garisto. History The journal was created in 1958. Samuel Goudsmit, who was then the editor of '' Physical Review'', the American Physical Society's flagship journal, organized and published ''Letters to the Editor of Physical Review'' into a new standalone journal'','' which became ''Physical Review Letters''. It was the first journal intended for the rapid publication of short articles, a format that eventually became popular in many other fiel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Richard Axel
Richard Axel (born July 2, 1946) is an American molecular biologist and university professor in the Department of Neuroscience at Columbia University and investigator at the Howard Hughes Medical Institute. His work on the olfactory system won him and Linda Buck, a former postdoctoral research scientist in his group, the Nobel Prize in Physiology or Medicine in 2004. Education and early life Born in New York City to Polish Jewish immigrants, Axel grew up in Brooklyn. He graduated from Stuyvesant High School in 1963, (along with Bruce Bueno de Mesquita, Allan Lichtman, Ron Silver, and Alexander Rosenberg), received his B.A. in 1967 from Columbia University, and his M.D. in 1971 from Johns Hopkins University. However, he was poorly suited to medicine and graduated on the promise to his department chairman that he would not practice clinically. He found his calling in research and returned to Columbia later that year, eventually becoming a full professor in 1978. Research and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Linda Buck
Linda Brown Buck (born January 29, 1947) is an American biologist best known for her work on the olfactory system. She was awarded the 2004 Nobel Prize in Physiology or Medicine, along with Richard Axel, for their work on olfactory receptors. She is currently on the faculty of the Fred Hutchinson Cancer Research Center in Seattle. Personal life Linda B. Buck was born in Seattle, Washington on January 29, 1947. Her father was an electrical engineer who spent his time inventing and building different items in his spare time, while her mother was a homemaker who spent a majority of her free time solving word puzzles. Buck was the second of three children, all of them girls. Her father has Irish ancestry as well as ancestors dating back to the American revolution. Her mother is of Swedish ancestry. In 1994 Buck met Roger Brent, also a biologist. The two married in 2006. Education Buck received her B.S. in psychology and microbiology in 1975 from the University of Washington, Seatt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
