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Gramicidin S
Gramicidin S or Gramicidin Soviet is an antibiotic that is effective against some gram-positive and gram-negative bacteria as well as some fungi. It is a derivative of gramicidin, produced by the gram-positive bacterium ''Brevibacillus brevis''. Gramicidin S is a cyclodecapeptide, constructed as two identical pentapeptides joined head to tail, formally written as ''cyclo''(- Val- Orn- Leu-D- Phe- Pro-)2. That is to say, it forms a ring structure composed of five different amino acids, each one used twice within the structure. Another interesting point is that it utilizes two amino acids uncommon in peptides: ornithine as well as the atypical stereoisomer of phenylalanine. It is synthesized by gramicidin S synthetase. Biosynthesis Gramicidin S biosynthetic pathway consists of two-enzyme of nonribosomal peptide synthases ( NRPSs), gramicidin S synthetase I (GrsA) and gramicidin S synthetase II (GrsB), to give a product as a cyclic decapeptide. Within the biosynthetic pat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Nature (journal)
''Nature'' is a British weekly scientific journal founded and based in London, England. As a multidisciplinary publication, ''Nature'' features Peer review, peer-reviewed research from a variety of academic disciplines, mainly in science and technology. It has core editorial offices across the United States, continental Europe, and Asia under the international scientific publishing company Springer Nature. ''Nature'' was one of the world's most cited scientific journals by the Science Edition of the 2022 ''Journal Citation Reports'' (with an ascribed impact factor of 50.5), making it one of the world's most-read and most prestigious academic journals. , it claimed an online readership of about three million unique readers per month. Founded in the autumn of 1869, ''Nature'' was first circulated by Norman Lockyer and Alexander MacMillan (publisher), Alexander MacMillan as a public forum for scientific innovations. The mid-20th century facilitated an editorial expansion for the j ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Gramicidin S Biosynthetic Pathway
Gramicidin, also called gramicidin D, is a mix of ionophoric antibiotics, gramicidin A, B and C, which make up about 80%, 5%, and 15% of the mix, respectively. Each has 2 isoforms, so the mix has 6 different types of gramicidin molecules. They can be extracted from ''Brevibacillus brevis'' soil bacteria. Gramicidins are linear peptides with 15 amino acids. This is in contrast to unrelated gramicidin S, which is a cyclic peptide. Medical uses Gramicidins work as antibiotics against gram-positive bacteria like ''Bacillus subtilis'' and ''Staphylococcus aureus'', but not well against gram-negative ones like ''E. coli''. Gramicidins are used in medicinal lozenges for sore throat and in topical medicines to treat infected wounds. Gramicidins are often mixed with other antibiotics like tyrocidine and antiseptics. Gramicidins are also used in eye drops for bacterial eye infections. In drops, they are often mixed with other antibiotics like polymyxin B or neomycin. Multiple antibioti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Crystal Structure Of Modified Gramicidin S
A crystal or crystalline solid is a solid material whose constituents (such as atoms, molecules, or ions) are arranged in a highly ordered microscopic structure, forming a crystal lattice that extends in all directions. In addition, macroscopic single crystals are usually identifiable by their geometrical shape, consisting of flat faces with specific, characteristic orientations. The scientific study of crystals and crystal formation is known as crystallography. The process of crystal formation via mechanisms of crystal growth is called crystallization or solidification. The word ''crystal'' derives from the Ancient Greek word (), meaning both "ice" and "rock crystal", from (), "icy cold, frost". Examples of large crystals include snowflakes, diamonds, and table salt. Most inorganic solids are not crystals but polycrystals, i.e. many microscopic crystals fused together into a single solid. Polycrystals include most metals, rocks, ceramics, and ice. A third category of sol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Geneticist
A geneticist is a biologist or physician who studies genetics, the science of genes, heredity, and variation of organisms. A geneticist can be employed as a scientist or a lecturer. Geneticists may perform general research on genetic processes or develop genetic technologies to aid in the pharmaceutical or and agriculture industries. Some geneticists perform experiments in model organisms such as '' Drosophila'', '' C. elegans'', zebrafish, rodents or humans and analyze data to interpret the inheritance of biological traits. A basic science geneticist is a scientist who usually has earned a PhD in genetics and undertakes research and/or lectures in the field. A medical geneticist is a physician who has been trained in medical genetics as a specialization and evaluates, diagnoses, and manages patients with hereditary conditions or congenital malformations; and provides genetic risk calculations and mutation analysis. Education Geneticists participate in courses from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Lysenkoism
Lysenkoism ( ; ) was a political campaign led by the Soviet biologist Trofim Lysenko against genetics and science-based agriculture in the mid-20th century, rejecting natural selection in favour of a form of Lamarckism, as well as expanding upon the techniques of vernalization and grafting. More than 3,000 mainstream biologists were dismissed or imprisoned, and numerous scientists were executed in the Soviet campaign to Suppressed research in the Soviet Union, suppress scientific opponents. The president of the Soviet Agriculture Academy, Nikolai Vavilov, who had been Lysenko's mentor, but later denounced him, was sent to prison and died there, while Soviet genetics research was effectively destroyed. Research and teaching in the fields of neurophysiology, cell biology, and many other biological disciplines were harmed or banned. The government of the Soviet Union (USSR) supported the campaign, and Joseph Stalin personally edited a speech by Lysenko in a way that reflected his s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Margaret Thatcher
Margaret Hilda Thatcher, Baroness Thatcher (; 13 October 19258 April 2013), was a British stateswoman who served as Prime Minister of the United Kingdom from 1979 to 1990 and Leader of the Conservative Party (UK), Leader of the Conservative Party from 1975 to 1990. She was the List of prime ministers of the United Kingdom by length of tenure, longest-serving British prime minister of the 20th century and the first woman to hold the position. As prime minister, she implemented policies that came to be known as Thatcherism. A Soviet journalist dubbed her the "Iron Lady", a nickname that became associated with her uncompromising politics and leadership style. Thatcher studied chemistry at Somerville College, Oxford, and worked briefly as a research chemist before becoming a Barristers in England and Wales, barrister. She was List of MPs elected in the 1959 United Kingdom general election, elected Member of Parliament for Finchley (UK Parliament constituency), Finc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Gerhard Schmidt (crystallographer)
Gerhard Martin Julius Schmidt (; 21 August 1919 in Berlin – 12 July 1971, in Zurich, buried in Rehovot), was an organic chemist and chemical crystallographer, dean of the chemistry faculty of the Weizmann Institute of Science, and its scientific director in 1969. Schmidt was the founder of X-ray crystallography at the Weizmann Institute and in Israel – a field in which Weizmann Institute's Professor Ada Yonath was awarded the Nobel Prize in Chemistry for 2009. Early years Schmidt was born in Berlin in 1919 and went to high school in Munich, where his father was a professor of chemistry. Being the son of a Jewish mother, Gerhard was forced to leave Germany at the age of 16, after the Nazis came to power; he spent a year in Switzerland, then moved to England, where he finished high school in 1938. He then won a scholarship to study at the University of Oxford (Oriel College). He earned a master's degree in organic chemistry in 1942 under the guidance of Robert Robinson, and a d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Dorothy Hodgkin
Dorothy Mary Crowfoot Hodgkin (née Crowfoot; 12 May 1910 – 29 July 1994) was a Nobel Prize-winning English chemist who advanced the technique of X-ray crystallography to determine the structure of biomolecules, which became essential for structural biology. Among her most influential discoveries are the confirmation of the structure of penicillin as previously surmised by Edward Abraham and Ernst Boris Chain; and mapping the structure of vitamin B12, vitamin B12, for which in 1964 she became the third woman to win the Nobel Prize in Chemistry. Hodgkin also elucidated the structure of insulin in 1969 after 35 years of work. Hodgkin used the name "Dorothy Crowfoot" until twelve years after marrying Thomas Lionel Hodgkin, when she began using "Dorothy Crowfoot Hodgkin". Hodgkin is referred to as "Dorothy Hodgkin" by the Royal Society (when referring to its sponsorship of the Dorothy Hodgkin fellowship), and by Somerville College. The National Archives (United Kingdom), The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Nobel Prize
The Nobel Prizes ( ; ; ) are awards administered by the Nobel Foundation and granted in accordance with the principle of "for the greatest benefit to humankind". The prizes were first awarded in 1901, marking the fifth anniversary of Alfred Nobel, Alfred Nobel's death. The original Nobel Prizes covered five fields: Nobel Prize in Physics, physics, Nobel Prize in Chemistry, chemistry, Nobel Prize in Physiology or Medicine, physiology or medicine, Nobel Prize in Literature, literature, and Nobel Peace Prize, peace, specified in Nobel's will. A sixth prize, the Nobel Memorial Prize in Economic Sciences, Prize in Economic Sciences, was established in 1968 by Sveriges Riksbank (Sweden's central bank) in memory of Alfred Nobel. The Nobel Prizes are widely regarded as the most prestigious awards available in their respective fields.Nobel Prize#Shalev69, Shalev, p. 8. Except in extraordinary circumstances, such as war, all six prizes are given annually. Each recipient, known as a laur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Richard Synge
Richard Laurence Millington Synge (28 October 1914 – 18 August 1994) was a British biochemist, and shared the 1952 Nobel Prize in Chemistry for the invention of partition chromatography with Archer Martin. Life Richard Laurence Millington Synge was born in West Kirby on 28 October 1914, the son of Lawrence Millington Synge, a Liverpool stock-broker, and his wife, Katherine C. Swan. Synge was educated at the Old Hall in Wellington, Shropshire and at Winchester College. He then studied Chemistry at Trinity College, Cambridge. He spent his entire career in research, at the Wool Industries Research Association, Leeds (1941–1943), Lister Institute for Preventive Medicine, London (1943–1948), Rowett Research Institute, Aberdeen (1948–1967), and Food Research Institute, Norwich (1967–1976). It was during his time in Leeds that he worked with Archer Martin, developing partition chromatography, a technique used in the separation mixtures of similar chemicals, that revolutio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
International Red Cross
The International Committee of the Red Cross (ICRC) is a aid agency, humanitarian organization based in Geneva, Switzerland, and is a three-time Nobel Prize laureate. The organization has played an instrumental role in the development of Law of war, rules of war and promoting Humanitarianism, humanitarian norms. State parties (signatories) to the Geneva Convention of 1949 and its Additional Protocols of 1977 (Protocol I, Protocol II) and Protocol III, 2005 have given the ICRC a mandate to protect victims of international and internal war, armed conflicts. Such victims include war wounded persons, prisoners, refugees, civilians, and other non-combatants. The ICRC is part of the International Red Cross and Red Crescent Movement, along with the International Federation of Red Cross and Red Crescent Societies (IFRC) and 191 List of Red Cross and Red Crescent Societies, National Societies. It is the oldest and most honoured organization within the movement and one of the most widely ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Great Britain
Great Britain is an island in the North Atlantic Ocean off the north-west coast of continental Europe, consisting of the countries England, Scotland, and Wales. With an area of , it is the largest of the British Isles, the List of European islands by area, largest European island, and the List of islands by area, ninth-largest island in the world. It is dominated by a maritime climate with narrow temperature differences between seasons. The island of Ireland, with an area 40 per cent that of Great Britain, is to the west – these islands, along with over List of islands of the British Isles, 1,000 smaller surrounding islands and named substantial rocks, comprise the British Isles archipelago. Connected to mainland Europe until 9,000 years ago by a land bridge now known as Doggerland, Great Britain has been inhabited by modern humans for around 30,000 years. In 2011, it had a population of about , making it the world's List of islands by population, third-most-populous islan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
