| pivalate | USAN-approved contraction for trimethylacetate, (CH3)3C-CO2-. (05 Mar 2000) |
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| pivampicillin | <chemical> 6-((aminophenylacetyl)amino)-3,3-dimethyl-7-oxo-4-thia-1- azabicyclo(3.2.0)heptane-2-carboxylic acid (2,2-dimethyl- 1-oxopropoxy)methyl ester. Pivalate ester analog of ampicillin. Pharmacological action: penicillins. Chemical name: 4-Thia-1-azabicyclo(3.2.0)heptane-2-carboxylic acid, 6-((aminophenylacetyl)amino)-3,3-dimethyl-7-oxo-, (2,2-dimethyl-1-oxopropoxy)methyl ester, (2S-(2alpha,5alpha,6beta(S*)))- (12 Dec 1998) |
| pivot | 1. A fixed pin or short axis, on the end of which a wheel or other body turns. 2. The end of a shaft or arbor which rests and turns in a support; as, the pivot of an arbor in a watch. 3. Hence, figuratively: A turning point or condition; that on which important results depend; as, the pivot of an enterprise. 4. The officer or soldier who simply turns in his place whike the company or line moves around him in wheeling; called also pivot man. Pivot bridge, a form of drawbridge in which one span, called the pivot span, turns about a central vertical axis. Pivot gun, a gun mounted on a pivot or revolving carriage, so as to turn in any direction. <dentistry> Pivot tooth, an artificial crown attached to the root of a natural tooth by a pin or peg. Origin: F.; prob. Akin to It. Piva pipe, F. Pipe. See Pipe. Source: Websters Dictionary (01 Mar 1998) |
| pivot joint | A synovial joint in which a section of a cylinder of one bone fits into a corresponding cavity on the other, as in the proximal radioulnar joint. Synonym: articulatio trochoidea, helicoid ginglymus, lateral ginglymus, rotary joint, rotatory joint, trochoid articulation, trochoid joint. (05 Mar 2000) |
| pivot shift test | A manoeuvre to detect a deficiency of the anterior cruciate ligament of the knee; when the knee is extended, a sudden subluxation of the lateral tibial condyle upon the distal femur is positive. (05 Mar 2000) |