| prian | <chemical> A fine, white, somewhat friable clay; also, the ore contained in a mixture of clay and pebbles. Alternative forms: pryan. Origin: Cornish, clayey ground, from pri clay. Source: Websters Dictionary (01 Mar 1998) |
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| priapism | <urology> Persistent abnormal erection of the penis, usually without sexual desire and accompanied by pain and tenderness. It is seen in diseases and injuries of the spinal cord and may be caused by vesical calculus and certain injuries to the penis. Origin: L. Priapismus, Gr. Priapismos (13 Nov 1997) |
| priapulacea | <zoology> A suborder of Gephyraea, having a cylindrical body with a terminal anal opening, and usually with one or two caudal gills. See: priapism. (05 Mar 1998) |
| priapus | Synonym: penis. Origin: L. Fr. Priapus (G. Priapos), god of procreation (05 Mar 2000) |
| Pribnow | David, 20th-century U.S. Molecular biologist. See: Pribnow box. (05 Mar 2000) |
| Pribnow box | <molecular biology> A region of DNA to which RNA polymerase binds before initiating the transcription of DNA into RNA. The nucleotide at which transcription starts is designated +1 and nucleotides are numbered from this with negative numbers indicating upstream nucleotides and positive downstream nucleotides. most bacterial promoters contain two consensus sequences that seem to be essential for the binding of the polymerase. The first, the Pribnow box, is at about 10 and has the consensus sequence 5' TATAAT 3'. The second, the 35 sequence, is centred about 35 and has the consensus sequence 5' TTGACA 3'. most factors that regulate gene transcription do so by binding at or near the promoter and affecting the initiation of transcription. Much less is known about eukaryote promoters, each of the three RNA polymerases has a different promoter. RNA polymerase I recognises a single promoter for the precursor of rRNA. RNA polymerase II, that transcribes all genes coding for polypeptides, recognises many thousands of promoters. most have the Goldberg Hogness or TATA box that is centred around position 25 and has the consensus sequence 5' TATAAAA 3'. Several promoters have a CAAT box around 90 with the consensus sequence 5' GGCCAATCT 3'. There is increasing evidence that all promoters for housekeeping genes contain multiple copies of a GC rich element that includes the sequence 5' GGGCGG 3'. Transcription by polymerase II is also affected by more distant elements known as enhancers. RNA polymerase III synthesises 5s ribosomal RNA, all tRNAs and a number of small RNAs. The promoter for RNA polymerase III is located within the gene either as a single sequence, as in the 5s RNA gene or as two blocks, as in all tRNA genes. (13 Nov 1997) |
| Price | Ernest Arthur, English biochemist, *1882. See: Carr-Price reaction. (05 Mar 2000) |
| price lists | Lists giving the prices of items for sale, including drugs, equipment, books, etc. Price lists are less detailed than catalogs and not as long. (12 Dec 1998) |
| Price-Jones | Cecil, English haematologist, 1863-1943. See: Price-Jones curve. (05 Mar 2000) |
| Price-Jones curve | A distribution curve of the measured diameters of red blood cells; it is to the right of the normal curve (i.e., indicating larger diameters) in instances of pernicious anaemia and other forms in which macrocytes are present, and to the left (i.e., indicating smaller diameters) in iron deficiency and other forms of microcytic anaemia. (05 Mar 2000) |
| priceite | <alchemy> A hydrous borate of lime, from Oregon. Origin: From Thomas Price of San Francisco. Source: Websters Dictionary (01 Mar 1998) |
| prick | 1. To be punctured; to suffer or feel a sharp pain, as by puncture; as, a sore finger pricks. 2. To spur onward; to ride on horseback. "A gentle knight was pricking on the plain." (Spenser) 3. To become sharp or acid; to turn sour, as wine. 4. To aim at a point or mark. 1. That which pricks, penetrates, or punctures; a sharp and slender thing; a pointed instrument; a goad; a spur, etc.; a point; a skewer. "Pins, wooden pricks, nails, sprigs of rosemary." (Shak) "It is hard for thee to kick against the pricks." (Acts ix. 5) 2. The act of pricking, or the sensation of being pricked; a sharp, stinging pain; figuratively, remorse. "The pricks of conscience." 3. A mark made by a pointed instrument; a puncture; a point. Hence: A point or mark on the dial, noting the hour. "The prick of noon." The point on a target at which an archer aims; the mark; the pin. "They that shooten nearest the prick." . A mark denoting degree; degree; pitch. "To prick of highest praise forth to advance." Spenser. A mathematical point; regularly used in old English translations of Euclid. The footprint of a hare. 4. A small roll; as, a prick of spun yarn; a prick of tobacco. Origin: AS. Prica, pricca, pricu; akin to LG. Prick, pricke, D. Prik, Dan. Prik, prikke, Sw. Prick. Cf. Prick. 1. To pierce slightly with a sharp-pointed instrument or substance; to make a puncture in, or to make by puncturing; to drive a fine point into; as, to prick one with a pin, needle, etc.; to prick a card; to prick holes in paper. 2. To fix by the point; to attach or hang by puncturing; as, to prick a knife into a board. "The cooks prick it [a slice] on a prong of iron." (Sandys) 3. To mark or denote by a puncture; to designate by pricking; to choose; to mark; sometimes with off. "Some who are pricked for sheriffs." (Bacon) "Let the soldiers for duty be carefully pricked off." (Sir W. Scott) "Those many, then, shall die: their names are pricked." (Shak) 4. To mark the outline of by puncturing; to trace or form by pricking; to mark by punctured dots; as, to prick a pattern for embroidery; to prick the notes of a musical composition. 5. To ride or guide with spurs; to spur; to goad; to incite; to urge on; sometimes with on, or off. "Who pricketh his blind horse over the fallows." (Chaucer) "The season pricketh every gentle heart." (Chaucer) "My duty pricks me on to utter that." (Shak) 6. To affect with sharp pain; to sting, as with remorse. "I was pricked with some reproof." "Now when they heard this, they were pricked in their heart." (Acts II. 37) 7. To make sharp; to erect into a point; to raise, as something pointed; said especially of the ears of an animal, as a horse or dog; and usually followed by up; hence, to prick up the ears, to listen sharply; to have the attention and interest strongly engaged. "The courser . . . Pricks up his ears." 8. To render acid or pungent. 9. To dress; to prink; usually with up. 10. To run a middle seam through, as the cloth of a sail. To trace on a chart, as a ship's course. 11. <veterinary> To drive a nail into (a horse's foot), so as to cause lameness. To nick. Origin: AS. Prician; akin to LG. Pricken, D. Prikken, Dan. Prikke, Sw. Pricka. See Prick, and cf. Prink, Prig. Source: Websters Dictionary (01 Mar 1998) |
| prick-eared | <zoology> Having erect, pointed ears; said of certain dogs. "Thou prick-eared cur of Iceland." (Shak) Source: Websters Dictionary (01 Mar 1998) |
| pricker | 1. One who, or that which, pricks; a pointed instrument; a sharp point; a prickle. 2. One who spurs forward; a light horseman. "The prickers, who rode foremost, . . . Halted." (Sir W. Scott) 3. A priming wire; a priming needle, used in blasting and gunnery. 4. A small marline spike having generally a wooden handle, used in sailmaking. Source: Websters Dictionary (01 Mar 1998) |
| pricket | <zoology> A buck in his second year. Origin: Perhaps so called from the state of his horns. Source: Websters Dictionary (01 Mar 1998) |