| echocardiography, three-dimensional | Echocardiography amplified by the addition of depth to the conventional two-dimensional echocardiography visualizing only the length and width of the heart. Three-dimensional ultrasound imaging was first described in 1961 but its application to echocardiography did not take place until 1974. (mayo clin proc 1993;68:221-40) (12 Dec 1998) |
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| bufadienolides (two double bonds) | Bufatrienolides (three double bonds), etc; they have varying numbers of hydroxyl groups at positions 3, 5, 14, and 16, and these may be further substituted. For structure, see steroids. (05 Mar 2000) |
| gel diffusion precipitin tests in two dimensions | Precipitin test's made in a layer of agar that permits radial diffusion, in both of the horizontal dimensions, of one or both reactants. Double (gel) diffusion in two dimensions (Ouchterlony test, technique, or method) incorporates antigen and antibody solutions placed in separate wells in a sheet of plain agar, permitting radial diffusion of both reactants; this method is widely used to determine antigenic relationships; the bands of precipitate that form where the reactants meet in optimal concentration are of three patterns, referred to as reaction of identity, reaction of partial identity (cross-reaction), and reaction of nonidentity. (05 Mar 2000) |
| Master's two-step exercise test | An early and long-used exercise challenge to identify ischemic heart disease using a pair of nine inch steps with a platform on top, the number of trips by the patient arbitrarily chosen and related to age and body weight. See: two-step exercise test. Synonym: Master's two-step exercise test. (05 Mar 2000) |
| two | One and one; twice one. "Two great lights." . "Two black clouds." Two is often joined with other words, forming compounds signifying divided into, consisting of, or having, two parts, divisions, organs, or the like; as two-bladed, two-celled, two-eared, two-flowered, twohand, two-headed, two-horse, two-leafed or two-leaved, two-legged, two-lobed, two-masted, two-named, two-part, two-petaled, two-pronged, two-seeded, two-sided, two-story, two-stringed, two-foothed, two-valved, two-winged, and the like. One or two, a phrase often used indefinitely for a small number. Source: Websters Dictionary (01 Mar 1998) |
| two-bellied muscle | <anatomy> One of the suprahyoid group of muscles consisting of two bellies united by a central tendon which is connected to the body of the hyoid bone; origin, by posterior belly from the digastric groove medial to the mastoid process; insertion, by anterior belly into lower border of mandible near midline; action, elevates the hyoid when mandible is fixed; depresses the mandible when hyoid is fixed; nerve supply, posterior belly from facial, anterior belly by nerve to the mylohyoid from the mandibular division of trigeminal, a muscle with two fleshy bellies separated by a fibrous insertion. Synonym: musculus digastricus, biventer mandibulae, musculus biventer mandibulae, two-bellied muscle. (05 Mar 2000) |
| two-capsuled | <botany> Having two distinct capsules; bicapsular. Source: Websters Dictionary (01 Mar 1998) |
| two-carbon fragment | The acetyl group (CH3CO-) that takes part in transacetylation reactions with coenzyme A as carrier; commonly referred to as acetate or acetic acid, from which it is derived. (05 Mar 2000) |
| two-cleft | <botany> Divided about half way from the border to the base into two segments; bifid. Source: Websters Dictionary (01 Mar 1998) |
| two-component plasma | <radiobiology> Refers to a plasma containing a cool thermal component and a population of high energy particles (such as from neutral beam injection) which are in the process of thermalising (slowing down). (09 Oct 1997) |
| two-glass test | The urine, in a case of gonorrhoea, is passed into two glasses; if the gonococci and gonorrhoeal threads are found only in the first glass the probability is that the process is limited to the anterior urethra. Synonym: two-glass test. (05 Mar 2000) |
| two-hand | Employing two hangs; as, the two-hand alphabet. See Dactylology. Source: Websters Dictionary (01 Mar 1998) |
| two-handed | 1. Having two hands; often used as an epithet equivalent to large, stout, strong, or powerful. "Two-handed sway." 2. Used with both hands; as, a two-nanded sword. "That two-handed engine [the sword]" (Milton) 3. Using either hand equally well; ambidextrous. Source: Websters Dictionary (01 Mar 1998) |
| two-lipped | 1. Having two lips. 2. <botany> Divided in such a manner as to resemble the two lips when the mouth is more or less open; bilabiate. Source: Websters Dictionary (01 Mar 1998) |
| two-parted | <biology> Divided from the border to the base into two distinct parts; bipartite. <botany> Divided from the border to the base into two distinct parts; bipartite. Source: Websters Dictionary (01 Mar 1998) |