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17P Holmes
17P or 17.P or 17-P may refer to: * 17P/Holmes, a comet * SpaceShipOne flight 17P, a commercial spaceflight * 17α-Hydroxyprogesterone, a steroid hormone and intermediate * 17p, the short arm of the 17th human chromosome that has the p53 tumour suppressor gene * 17-Phenylandrostenol * 17-pounder The Ordnance Quick-Firing 17-pounder (or just 17-pdr)Under the British standard ordnance weights and measurements the gun's approximate projectile weight is used to denote different guns of the same calibre. Hence this was a 3-inch gun, of which ... See also * P17 (other) {{Letter-NumberCombDisambig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
17P/Holmes
Comet Holmes (official designation: 17P/Holmes) is a periodic comet in the Solar System, discovered by the British amateur astronomer Edwin Holmes on November 6, 1892. Although normally a very faint object, Holmes became notable during its October 2007 return when it temporarily brightened by a factor of a million, in what was the largest known outburst by a comet, and became visible to the naked eye. It also briefly became the largest object in the Solar System, as its coma (the thin dissipating dust ball around the comet) expanded to a diameter greater than that of the Sun (although its mass remained minuscule). Discovery Comet Holmes was discovered by Edwin Holmes on November 6, 1892, while he was conducting regular observations of the Andromeda Galaxy (M31). Its discovery in 1892 was possible because of an increase in its magnitude similar to the 2007 outburst; it brightened to an approximate magnitude of 4 or 5 before fading from visibility over a period of several wee ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SpaceShipOne Flight 17P
Flight 17P of SpaceShipOne was a spaceflight in the Tier One program that took place on October 4, 2004. It was the second competitive flight in the Ansari X Prize competition to demonstrate a non-governmental reusable crewed spacecraft, and is hence also referred to as the X2 flight. It was a successful flight, winning the X PRIZE. Crew Scheduling To win the X PRIZE, a spacecraft needed to make two successful competitive flights within 14 days. SpaceShipOne made a successful competitive flight on September 29, 2004, and so needed to make a second by October 13, 2004 in order to win. Scaled Composites aimed to be able to fly three times within the two weeks in order to allow for a failed flight. The date of the flight, October 4, 2004, was the 47th anniversary of the launch of Sputnik 1, the first artificial satellite to orbit the Earth and the same day astronaut Gordon Cooper died. SpaceShipOne's first powered flight was, in a similar vein, on the 100th anniversary o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
17α-Hydroxyprogesterone
17α-Hydroxyprogesterone (17α-OHP), also known as 17-OH progesterone (17-OHP), or hydroxyprogesterone (OHP), is an endogenous progestogen steroid hormone related to progesterone. It is also a chemical intermediate in the biosynthesis of many other endogenous steroids, including androgens, estrogens, glucocorticoids, and mineralocorticoids, as well as neurosteroids. Biological activity 17α-OHP is an agonist of the progesterone receptor (PR) similarly to progesterone, albeit weakly in comparison. In addition, it is an antagonist of the mineralocorticoid receptor (MR) as well as a partial agonist of the glucocorticoid receptor (GR), albeit with very low potency ( EC50 >100-fold less relative to cortisol) at the latter site, also similarly to progesterone. Biochemistry Biosynthesis 17α-OHP is derived from progesterone via 17α-hydroxylase (encoded by CYP17A1) 17α-OHP increases in the third trimester of pregnancy primarily due to fetal adrenal production. This steroid is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chromosome 17 (human)
Chromosome 17 is one of the 23 pairs of chromosomes in humans. People normally have two copies of this chromosome. Chromosome 17 spans more than 83 million base pairs (the building material of DNA) and represents between 2.5 and 3% of the total DNA in cells. Chromosome 17 contains the Homeobox B gene cluster. Genes Number of genes The following are some of the gene count estimates of human chromosome 17. Because researchers use different approaches to genome annotation their predictions of the number of genes on each chromosome varies (for technical details, see gene prediction). Among various projects, the collaborative consensus coding sequence project ( CCDS) takes an extremely conservative strategy. So CCDS's gene number prediction represents a lower bound on the total number of human protein-coding genes. Gene list The following is a partial list of genes on human chromosome 17. For complete list, see the link in the infobox on the right. The following are some ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
17-Phenylandrostenol
17-Phenylandrostenol (17-PA), or (3α,5α)-17-phenylandrost-16-en-3-ol, is a steroid drug which binds to GABAA receptors. It acts as an antagonist against the sedative effects of neuroactive steroids, but has little effect when administered by itself, and does not block the effects of benzodiazepines or barbiturates. Chemistry See also * Androstenol Androstenol, also known as 5α-androst-16-en-3α-ol (shortened to 3α,5α-androstenol or 3α-androstenol), is a 16-androstene class steroidal pheromone and neurosteroid in humans and other mammals, notably pigs. It possesses a characteristic musk ... References Androstanes GABAA receptor negative allosteric modulators Neurosteroids {{steroid-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
17-pounder
The Ordnance Quick-Firing 17-pounder (or just 17-pdr)Under the British standard ordnance weights and measurements the gun's approximate projectile weight is used to denote different guns of the same calibre. Hence this was a 3-inch gun, of which there were several types in British service, which fired a projectile weighing approximately was a 76.2 mm (3 inch) gun developed by the United Kingdom during World War II. It was used as an anti-tank gun on its own carriage, as well as equipping a number of British tanks. Used with the Armour-piercing discarding sabot, APDS shot, it was capable of defeating all but the thickest vehicle armour, armour on German tanks. It was used to 'up-gun' some foreign-built vehicles in British service, notably to produce the Sherman Firefly variant of the US M4 Sherman tank, giving British tank units the ability to hold their own against their German counterparts. In the anti-tank role, it was replaced after the war by the 120 mm BAT recoilles ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
