| vat | 1. A large vessel, cistern, or tub, especially one used for holding in an immature state, chemical preparations for dyeing, or for tanning, or for tanning leather, or the like. "Let him produce his vase and tubs, in opposition to heaps of arms and standards." (Addison) 2. A measure for liquids, and also a dry measure; especially, a liquid measure in Belgium and Holland, corresponding to the hectoliter of the metric system, which contains 22.01 imperial gallons, or 26.4 standard gallons in the United States. The old Dutch grain vat averaged 0.762 Winchester bushel. The old London coal vat contained 9 bushels. The solid-measurement vat of Amsterdam contains 40 cubic feet; the wine vat.57 imperial gallons, and the vat for olive oil.45 imperial gallons. 3. <chemistry> A wooden tub for washing ores and mineral substances in. A square, hollow place on the back of a calcining furnace, where tin ore is laid to dry. 4. A vessel for holding holy water. Origin: A dialectic form for fat, OE. Fat, AS. Faet; akin to D.vat, OS. Fat, G. Fass, OHG. Faz, Icel. & Sw. Fat, Dan.fad, Lith. Pdas a pot, and probably to G. Fassen to seize, to contain, OHG. Fazzn, D. Vatten. Cf. Fat a vat. Source: Websters Dictionary (01 Mar 1998) |
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| VAT ATPase | <enzyme> A member of the cdc48/p97 family of atpases; isolated from thermoplasma acidophilum; genbank u78072; do confuse with vat protein Registry number: EC 3.6.1.- Synonym: vcp-like atpase, thermoplasma, vat gene product, thermoplasma (26 Jun 1999) |
| artificial pacemaker | Any device that substitutes for the normal pacemaker and controls the rhythm of the organ; especially an electronic cardiac pacemaker, which may be implanted in the chest, with electrodes attached to the external cardiac surface, or passed through the venous circulation into the right side of the heart (pervenous pacemaker). (05 Mar 2000) |
| cardiac pacemaker | An electrical device which delivers a small stimulant shock to the heart to effect cardiac contraction at a pre-determined rate. Many of today's pacemakers have two main components: the electrodes and the transducer (pulse generator). The electrodes are wires which are placed into the circulatory system and make physical contact with the heart muscle. A small electrical discharge from the pacemaker electrode stimulates the muscular wall of the heart to contract, thus pumping blood in an organised fashion. The transducer is a small device, usually implanted under the skin, that generates the electrical discharge at a pre-determined frequency. Transducers can monitor your heart's rate of contraction and deliver an electrical shock only when the heart is going too slow. (27 Sep 1997) |
| pacemaker | 1. <apparatus, physiology> An object or substance that influences the rate at which a certain phenomenon occurs, often used alone to indicate the natural cardiac pacemaker or an artificial cardiac pacemaker. 2. <biochemistry> A substance whose rate of reaction sets the pace for a series of interrelated reactions. (24 Mar 1998) |
| pacemaker, artificial | A device designed to stimulate, by electric impulses, contraction of the heart muscles. It may be temporary (external) or permanent (internal or internal-external). (12 Dec 1998) |
| pacemaker failure | Failure of an artificial pacemaker to generate or deliver effective stimuli to the myocardium. (05 Mar 2000) |
| pacemaker output | Electrical energy delivered into a standard load (500 ohms resistance). (05 Mar 2000) |
| pacemaker potential | The voltage inscribed by impulses from an artificial electronic pacemaker. (05 Mar 2000) |
| pacemaker sensitivity | The minimum cardiac activity required to consistently trigger a pulse generator. (05 Mar 2000) |
| pacemaker syndrome | <syndrome> The occurrence of symptoms relating to the loss of atrial-ventricular synchrony in ventricularly paced patients, or symptoms caused by inadequate timing of atrial and ventricular contractions in paced patients. (05 Mar 2000) |
| refractory period of electronic pacemaker | The time required to restore full sensitivity after detecting cardiac activity or delivering a pacing impulse. (05 Mar 2000) |
| pervenous pacemaker | An artificial pacemaker passed through the venous circulation into the right side of the heart. (05 Mar 2000) |
| runaway pacemaker | Rapid heart rates over 140/min caused by electronic circuit instability in an implanted pulse generator. (05 Mar 2000) |
| wandering pacemaker | A disturbance of the normal cardiac rhythm in which the site of the controlling pacemaker shifts from beat to beat, usually between the sinus and A-V nodes, often with gradual sequential changes in P waves between upright and inverted in a given ECG lead. Synonym: shifting pacemaker. (05 Mar 2000) |