| TPG | transmembrane potential gradient; transplacental gradient; tryptophan peptone glucose [broth] |
|---|---|
| PSG | peak systolic gradient; phosphate, saline, and glucose; polysomnogram; presystolic gallop; pregnancy... |
| PIP | paralytic infantile paralysis; peak inflation pressure, peak inspiratory pressure; periodic interim ... |
| PPT | parietal pleural tissue; partial prothrombin time; peak-to-peak threshold; Pfeiffer-Palm-Teller [syn... |
| BS | Bachelor of Science; Bachelor of Surgery; Bacillus subtilis; Bartter syndrome; base strap; bedside; ... |
| strength-duration curve | A graph relating the intensity of an electrical stimulus to the length of time it must flow to be effective. See: chronaxie, rheobase. (05 Mar 2000) |
|---|---|
| ionic strength | Symbolised as g/2 or I and set equal to 0.5σmizi2, where mi equals the molar concentration and zi the charge of each ion present in solution; if molar concentrations (ci) are used instead of molality (and the solution is dilute), then I == 0.5(1/ρo)σcizi2 where ρo is the density of the solvent; a number of biochemically important events (e.g., protein solubility and rates of enzyme action) vary with the ionic strength of a solution. (05 Mar 2000) |
| tensile strength | The maximum stress a material subjected to a stretching load can withstand without tearing. (12 Dec 1998) |
| juxtaphrenic peak | On chest radiograph, a triangular density on top of the right diaphragmatic shadow, probably caused by tension of the phrenic nerve on the pleura over the diaphragm. (05 Mar 2000) |
| yield strength | The amount of stress at which a permanent (plastic) deformation in a component becomes measurable (usually taken as 0.2% permanent strain). (05 Mar 2000) |
| ultimate strength | The maximum stress achieved prior to failure of a component on a single application of the load. (05 Mar 2000) |
| fatigue strength | The stress level below which a particular component will survive an indefinite number of load cycles (typically about 50% of the ultimate strength of the component). (05 Mar 2000) |
| atrioventricular gradient | The diastolic pressure difference between the atrium and ventricle. (05 Mar 2000) |
| magnetic field gradient | In magnetic resonance imaging, a magnetic field that varies with location, superimposed on the uniform field of the magnet, to alter the resonant frequency of nuclei and allow recovery of their spatial position. Synonym: field gradient. (05 Mar 2000) |
| ventricular gradient | The algebraic sum of (i.e., the net electrical difference between) the area enclosed within the QRS complex and that within the T wave in the electrocardiogram. (05 Mar 2000) |
| voltage gradient | <physiology> Literally, the electric field in a region, defined as the potential difference between two points divided by the distance between them. Used more loosely, the potential difference across a plasma membrane. (18 Nov 1997) |
| centrifugation, density gradient | Separation of particles according to density by employing a gradient of varying densities. at equilibrium each particle settles in the gradient at a point equal to its density. (12 Dec 1998) |
| cesium chloride gradient centrifugation | A type of density gradient centrifugation, a lab technique used to separate or purify nucleic acids. It involves putting cesium chloride and the nucleic acids into a centrifuge to be spun for hours or days. The cesium chloride forms a density gradient (highly dense at the bottom, thinnest at the top), and the different nucleic acids separate along the gradient according to their buoyancies in different densities. (09 Oct 1997) |
| gradient | <physics> Mathematical term for the operator which determines the magnitude and direction of the greatest rate-of-change of a given function with position. Similarly used to describe such a rate-of-change. For instance, at a given point on a hill, the slope of the hill in the steepest uphill direction is the gradient of the altitude function for the hill. (09 Oct 1997) |
| gradient elution | Elution in column chromatography in which a changing pH or ionic strength is used to separate substances. (05 Mar 2000) |