| thalline | <botany> Consisting of a thallus. <chemistry> An artificial alkaloid of the quinoline series, obtained as a white crystalline substance, C10H13NO, whose salts are valuable as antipyretics; so called from the green colour produced in its solution by certain oxidizing agents. Origin: Gr. A young shoot or branch. Source: Websters Dictionary (01 Mar 1998) |
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| thallious | <chemistry> See Thallous. Source: Websters Dictionary (01 Mar 1998) |
| thallium | <chemistry> A rare metallic element of the aluminium group found in some minerals, as certain pyrites, and also in the lead-chamber deposit in the manufacture of sulphuric acid. It is isolated as a heavy, soft, bluish white metal, easily oxidized in moist air, but preserved by keeping under water. Symbol Tl. Atomic weight 203.7. Origin: NL, fr. Gr. Young or green shoot or branch, twig. So called from a characteristic bright green line in its spectrum. Source: Websters Dictionary (01 Mar 1998) |
| thallium 201 | <radiology> Tl-201, half-life: 73 hours (ca. 3 days), radiation: 68-80 keV photons (mercury X-rays), 135 and 167 keV gamma rays, cyclotron produced see: myocardial perfusion imaging (12 Dec 1998) |
| thallium heart scan | <cardiology, investigation, radiology> A test which involves the introduction of a radioactive tracer into the bloodstream. The radioactive tracer is then measured with a special camera and a determination of coronary artery blood flow can be made. (27 Sep 1997) |
| thallium poisoning | A condition characterised by vomiting, diarrhoea, leg pains, and severe sensorimotor polyneuropathy; about three weeks after poisoning, temporary extensive loss of hair typically occurs; usually occurs after accidental ingestion of a rodenticide. (05 Mar 2000) |
| thallium radioisotopes | Unstable isotopes of thallium that decay or disintegrate emitting radiation. Tl atoms with atomic weights 198-202, 204, and 206-210 are thallium radioisotopes. (12 Dec 1998) |
| thallium stress test | <cardiology, investigation> This test is used to assess coronary blood flow before and after a period of strenuous exercise. Thallium testing involves the introduction of a radioactive tracer into the bloodstream. The radioactive tracer is then measured with a special camera and a determination of coronary artery blood flow can be made. (27 Sep 1997) |
| thallogen | <botany> One of a large class or division of the vegetable kingdom, which includes those flowerless plants, such as fungi, algae, and lichens, that consist of a thallus only, composed of cellular tissue, or of a congeries of cells, or even of separate cells, and never show a distinction into root, stem, and leaf. Origin: Gr. Young shoot or branch, frond + -gen. Source: Websters Dictionary (01 Mar 1998) |
| thalloid | <anatomy> Of or resembling a thallus. (09 Oct 1997) |
| thallophyta | <botany> A primary division of plant-like organisms including all forms consisting of one-celled and cell aggregates not clearly differentiated into root, stem, and leaf, includes algae, fungi, and lichens. (09 Oct 1997) |
| thallophyte | <botany> Same as Thallogen. Origin: Gr. Young shoot + plant. Source: Websters Dictionary (01 Mar 1998) |
| thallospore | An obsolete term for a reproductive asexual type of spore formed as an integral part of the thallus or mycelium, in contrast to a conidium formed on a specialised hypha. Origin: G. Thallos, a green twig, + sporos, seed (05 Mar 2000) |
| thallotoxicosis | Poisoning by thallium; marked by stomatitis, gastroenteritis, peripheral and retrobulbar neuritis, endocrine disorders, and alopecia. Origin: thallium + G. Toxikon, poison, + -osis, condition (05 Mar 2000) |
| thallous | <chemistry> Of or pertaining to thallium; derived from, or containing, thallium; specifically, designating those compounds in which the element has a lower valence as contrasted with the thallic compounds. Alternative forms: thallious. Source: Websters Dictionary (01 Mar 1998) |