| time-varied gain | In ultrasonography, an increase in receiver gain with time to compensate for loss in echo amplitude with depth, usually due to attenuation. Synonym: attenuation compensation, depth compensation, time compensation gain, time-compensated gain, time-varied gain control, time-varied gain. (05 Mar 2000) |
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| time-varied gain control | In ultrasonography, an increase in receiver gain with time to compensate for loss in echo amplitude with depth, usually due to attenuation. Synonym: attenuation compensation, depth compensation, time compensation gain, time-compensated gain, time-varied gain control, time-varied gain. (05 Mar 2000) |
| timeless | <molecular biology> Drosophila gene essential for the production of circadian rhythms. The protein product, TIM, may be necessary for the accumulation of the PER protein, the product of the per gene. TIM and PER associate with one another and the regulated interaction seems to determine the entry of PER into the nucleus: both TIM and PER are produced in a circadian cycle. (28 May 1998) |
| TIMI | Acronym for thrombolysis in myocardial infarction; a large multicenter controlled clinical trial. (05 Mar 2000) |
| timid | Wanting courage to meet danger; easily frightened; timorous; not bold; fearful; shy. "Poor is the triumph o'er the timid hare." (Thomson) Synonym: Fearful, timorous, afraid, cowardly, pusillanimous, faint-hearted, shrinking, retiring. Tim"idly, Tim"idness. Origin: L. Timidus, fr. Timere to fear; cf. Skr. Tam to become breathless, to become stupefief: cf. F. Timide. Source: Websters Dictionary (01 Mar 1998) |
| timnodonic acid | A 20-carbon fatty acid with five cis double bonds located on carbons 5, 8, 11, 14, and 17; an important component of fish oils; a precursor to the 3-series prostaglandins e.g., PGE3. (05 Mar 2000) |
| timolol | <chemical> A beta-adrenergic antagonist similar in action to propranolol. The levo-isomer is the more active. Timolol has been proposed as an antihypertensive, antiarrhythmic, antiangina, and antiglaucoma agent. It is also used in the treatment of migraine and tremor. Pharmacological action: adrenergic beta-antagonists, anti-arrhythmia agents, antihypertensive agents, sympatholytics. Chemical name: 2-Propanol, 1-((1,1-dimethylethyl)amino)-3-((4-(4-morpholinyl)-1,2,5-thiadiazol-3-yl)oxy)-, (S)- (12 Dec 1998) |
| timolol maleate | (-)-1-(tert-Butylamino)-3-[(4-morpholino-1,2,5-thiadiazol-3-yl)oxy]-2-propanol maleate;a beta-adrenergic blocking agent used in the treatment of hypertension and used in eyedrops in the treatment of chronic open-angle glaucoma. (05 Mar 2000) |
| timothy grass | <botany> A kind of grass (Phleum pratense) with long cylindrical spikes; called also herd's grass, in England, cat's-tail grass, and meadow cat's-tail grass. It is much prized for fodder. Origin: From Timothy Hanson, who carried the seed from New England to Maryland about 1720. Source: Websters Dictionary (01 Mar 1998) |
| timothy-hay bacillus | A saprophytic bacterium widely distributed in soil and dust and on plants. (12 Dec 1998) |
| tin | 1. <chemistry> An elementary substance found as an oxide in the mineral cassiterite, and reduced as a soft white crystalline metal, malleable at ordinary temperatures, but brittle when heated. It is not easily oxidized in the air, and is used chiefly to coat iron to protect it from rusting, in the form of tin foil with mercury to form the reflective surface of mirrors, and in solder, bronze, speculum metal, and other alloys. Its compounds are designated as stannous, or stannic. Symbol Sn (Stannum). Atomic weight 117.4. 2. Thin plates of iron covered with tin; tin plate. 3. Money. <chemistry> Block tin, stannous chloride, used as a mordant in dyeing and calico printing. Tin penny, a customary duty in England, formerly paid to tithingmen for liberty to dig in tin mines. Tin plate, thin sheet iron coated with tin. Tin pyrites. See Stannite. Origin: As. Tin; akin to D. Tin, G. Zinn, OHG. Zin, Icel. & Dan. Tin, Sw. Tenn; of unknown origin. Source: Websters Dictionary (01 Mar 1998) |
| tin compounds | Inorganic compounds that contain tin as an integral part of the molecule. (12 Dec 1998) |
| tin fluorides | <chemical> Inorganic fluorides of tin. They include both stannic fluoride (tin tetrafluoride) and stannous fluoride (tin difluoride). The latter is used in the prevention of dental caries. Pharmacological action: fluorides, topical. (12 Dec 1998) |
| tin oxide | SnO2;used in industry; it is a cause of pneumoconiosis. Synonym: tin oxide. (05 Mar 2000) |
| tin polyphosphates | Poly or pyrophosphates of tin. In conjunction with radioactive technetium these compounds are used as bone-scanning agents and in scintigraphy to diagnose myocardial and cerebral infarction. (12 Dec 1998) |