| Cotton effect | The positive and negative displacement from zero of the rotation of plane polarised monochromatic light and the change of monochromatic circularly polarised light into elliptically polarised light in the immediate vicinity of the absorption band of the substance through which the light passes. See: optical rotatory dispersion, circular dichroism. (05 Mar 2000) |
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| cotton-fibre embolism | Embolism by cotton fibres from sterile gauze used in intravenous medication or transfusion; may form as foreign body granulomas in small pulmonary arteries. (05 Mar 2000) |
| Cotton, Frank | <person> U.S. Chemist, *1930. See: Cotton effect. (05 Mar 2000) |
| cotton-mill fever | <chest medicine> Exposures to cotton dust during the production of yarns, linen and rope can produce chronic obstructive lung disease (after 10 years). Early symptoms include chest tightness. Treatment includes bronchodilators and removal from work environment. (21 Mar 1998) |
| cotton-root bark | Dried root bark of Gossypium herbaceum and other species of Gossypium (family Malvaceae). Has been used as an abortifacient and oxytocic. (05 Mar 2000) |
| purified cotton | Absorbent cotton in which the hairs of the seed of varieties of Gossypium and other allied species are freed from adhering impurities, deprived of fatty matter, bleached, and sterilised; used for tampons, etc. (05 Mar 2000) |
| soluble gun cotton | <chemistry> A substance resembling gun cotton in composition and properties, but distinct in that it is more highly nitrified and is soluble in alcohol, ether, etc. Synonym: pyroxyle. Source: Websters Dictionary (01 Mar 1998) |
| styptic cotton | Absorbent cotton wet with a dilute solution of ferric chloride, and then dried; applied locally as a haemostatic. (05 Mar 2000) |
| blood patch, epidural | The injection of autologous blood into the epidural space either as a prophylactic treatment immediately following an epidural puncture or for treatment of headache as a result of an epidural puncture. (12 Dec 1998) |
| butterfly patch | Origin: Perh. From the colour of a yellow species. AS. Buter-flege, buttor-fleoge; cf. G. Butterfliege, D. Botervlieg. See Butter, and Fly. <zoology> A general name for the numerous species of diurnal Lepidoptera. See: Illust. Under Aphrodite] Asclepias butterfly. See Asclepias. Butterfly fish, a kind of double clack valve, consisting of two semicircular clappers or wings hinged to a cross rib in the pump bucket. When open it somewhat resembles a butterfly in shape. Source: Websters Dictionary (01 Mar 1998) |
| patch clamp | <physiology> A specialised and powerful variant of voltage clamping, in which a patch electrode of relatively large tip diameter (5m) is pressed tightly against the plasma membrane of a cell, forming an electrically tight, gigohm seal. The current flowing through individual ion channels can then be measured. Different variants on this technique allow different surfaces of the plasma membrane to be exposed to the bathing medium: the contact just described is a cell attached patch. If the electrode is pulled away, leaving just a small disc of plasma membrane occluding the tip of the electrode, it is called an inside out patch. If suction is applied to a cell attached patch, bursting the plasma membrane under the electrode, a whole cell patch (similar to an intracellular recording) is formed. If the electrode is withdrawn from the whole cell patch, the membrane fragments adhering to the electrode reform a seal across the tip, forming an outside out patch. (15 Mar 2000) |
| patch clamping | <physiology> A specialised and powerful variant of voltage clamping, in which a patch electrode of relatively large tip diameter (5m) is pressed tightly against the plasma membrane of a cell, forming an electrically tight, gigohm seal. The current flowing through individual ion channels can then be measured. Different variants on this technique allow different surfaces of the plasma membrane to be exposed to the bathing medium: the contact just described is a cell attached patch. If the electrode is pulled away, leaving just a small disc of plasma membrane occluding the tip of the electrode, it is called an inside out patch. If suction is applied to a cell attached patch, bursting the plasma membrane under the electrode, a whole cell patch (similar to an intracellular recording) is formed. If the electrode is withdrawn from the whole cell patch, the membrane fragments adhering to the electrode reform a seal across the tip, forming an outside out patch. (15 Mar 2000) |
| patch-clamp techniques | An electrophysiologic technique for studying cells, cell membranes, and occasionally isolated organelles. All patch-clamp methods rely on a very high-resistance seal between a micropipette and a membrane; the seal is usually attained by gentle suction. The four most common variants include on-cell patch, inside-out patch, outside-out patch, and whole-cell clamp. Patch-clamp methods are commonly used to voltage clamp, that is control the voltage across the membrane and measure current flow, but current-clamp methods, in which the current is controlled and the voltage is measured, are also used. (15 Mar 2000) |
| patch test | A test of skin sensitiveness: a small piece of paper, tape, or a cup, wet with CO non-irritating diluted test fluid, is applied to skin of the upper back or upper outer arm and after 48 hours the area previously covered is compared with the uncovered surface; an erythematous reaction with vesicles occurs if the substance causes contact allergy. See: photo-patch test. (05 Mar 2000) |
| patch tests | Skin tests in which the sensitiser is applied to a patch of cotton cloth or gauze held in place for approximately 48-72 hours. It is used for the elicitation of a contact hypersensitivity reaction. (12 Dec 1998) |