| shoad | <chemical> A train of vein material mixed with rubbish; fragments of ore which have become separated by the action of water or the weather, and serve to direct in the discovery of mines. Alternative forms: shode. Origin: Cf. G. Schutt rubbish. Source: Websters Dictionary (01 Mar 1998) |
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| shoading | <chemical> The tracing of veins of metal by shoads. Alternative forms: shoding. Source: Websters Dictionary (01 Mar 1998) |
| shoal | A great multitude assembled; a crowd; a throng; said especially of fish; as, a shoal of bass. "Great shoals of people." "Beneath, a shoal of silver fishes glides." (Waller) Origin: AS. Scolu, sceolu, a company, multitude, crowd, akin to OS. Skola; probably originally, a division, and akin to Icel. Skilja to part, divide. See Skill, and cf. School. Of fishes. To assemble in a multitude; to throng; as, the fishes shoaled about the place. Origin: Shoaled; Shoaling. 1. A place where the water of a sea, lake, river, pond, etc, is shallow; a shallow. "The depth of your pond should be six feet; and on the sides some shoals for the fish to lay their span." (Mortimer) "Wolsey, that once trod the ways of glory, And sounded all the depths and shoals of honor." (Shak) 2. A sandbank or bar which makes the water shoal. "The god himself with ready trident stands, And opes the deep, and spreads the moving sands, Then heaves them off the shoals." (Dryden) Source: Websters Dictionary (01 Mar 1998) |
| shoaly | Full of shoals, or shallow places. "The tossing vessel sailed on shoaly ground." (Dryden) Source: Websters Dictionary (01 Mar 1998) |
| shoat | A young hog. Synonym: shote. Origin: M.E. Shote (05 Mar 2000) |
| shock | 1. <psychiatry> A sudden disturbance of mental equilibrium. 2. <cardiology> A condition of profound haemodynamic and metabolic disturbance characterised by failure of the circulatory system to maintain adequate perfusion of vital organs, it may result from inadequate blood volume (hypovolaemic shock), inadequate cardiac function (cardiogenic shock) or inadequate vasomotor tone (neurogenic shock, septic shock). (18 Nov 1997) |
| shock antigen | An antigen capable of producing anaphylactic shock in an animal that has been sensitised to it. (05 Mar 2000) |
| shock index | The quotient of the cardiac rate divided by the systolic blood pressure; normally approximately 0.5, but in shock (e.g., rising pulse rate with falling blood pressure), the index may reach 1.0. (05 Mar 2000) |
| shock lung | In shock, the development of oedema, impaired perfusion, and reduction in alveolar space so that the alveoli collapse. Synonym: pump lung, wet lung, white lung. (05 Mar 2000) |
| shock therapy | See: electroshock therapy. (05 Mar 2000) |
| shock treatment | See: electroshock therapy. (05 Mar 2000) |
| shock tube | <radiobiology> A gas-filled tube used in plasma physics to quickly ionize a gas. A capacitor bank charged to a high voltage is discharged into the gas at one tube end to ionize and heat the gas, producing a shock wave that may be studied as it travels down the tube. (09 Oct 1997) |
| shock wave | <radiobiology> Wave produced (for example, in a gas or plasma) as a result of a sudden violent disturbance. To produce a shock wave in a given region, the disturbance must take place in a shorter time than the time required for sound waves to traverse the region. (09 Oct 1997) |
| shock wave lithotripsy | A method of fragmenting calculi. (05 Mar 2000) |
| shock, cardiogenic | Shock caused by heart failure. The heart fails to pump blood effectively. For example, a heart attack (a myocardial infarction) can cause an abnormal ineffectual heart beat (an arhythmia) with very slow, rapid, or irregular contractions of the heart, impairing the heart's ability to pump blood, lowering the volume of blood going to vital organs. Cardiogenic shock can also be due to drugs that reduce heart function or an abnormally low level oxygen in the blood (hypoxaemia) caused, for instance, by lung disease. Whatever be the cause, blood vessels constrict and adrenalin-like substances are secreted into the bloodstream, increasing the heart rate. Treatment of cardiogenic shock is aimed at improving the heart's function. Shock after a heat attack is extremely serious. The mortality rate is over 80%. (12 Dec 1998) |