| ECD | ectrodactyly; electrochemical detector; electron capture detector; endocardial cushion defect; enzym... |
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| ERM | electrochemical relaxation method; extended radical mastectomy |
| AEP | acute edematous pancreatitis; artificial endocrine pancreas; auditory evoked potential; average evok... |
| AP | accessory pathway; accounts payable; acid phosphatase; acinar parenchyma; action potential; active p... |
| ERP | early receptor potential; effective refractory period; elodoisin-related peptide; endoscopic retrogr... |
| concentration gradient | <chemistry> A column of liquid in which the density varies continually with position, usually as a consequence of variation of concentration of a solute. Such gradients may be established by progressive mixing of solutions of different density as for example: sucrose gradients) or by centrifuge induced redistribution of solute (as for caesium chloride gradients). Density gradients are widely used for centrifugal and gravity induced separations of cells, organelles and macromolecules. The separations may exploit density differences between particles or primarily differences in size, in which latter case the function of the gradient is chiefly to stabilise the liquid column against mixing. (12 Jan 1998) |
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| critical gradient | <botany> The maximum stable inclination of an unsupported slope under the most adverse conditions that it will likely experience, as determined by current engineering technology. (09 Oct 1997) |
| pseudospatial gradient sensing | <cell biology> Mechanism for sensing a gradient of a diffusible chemical in which the cell sends protrusions out at random, up gradient protrusions are stabilised by positive feedback (because receptor occupancy is rising with time) and others are transitory because of adaptation. Possibly the mechanism by which neutrophils sense chemotactic gradients. (18 Nov 1997) |
| density gradient | <chemistry> A column of liquid in which the density varies continually with position, usually as a consequence of variation of concentration of a solute. Such gradients may be established by progressive mixing of solutions of different density as for example: sucrose gradients) or by centrifuge induced redistribution of solute (as for caesium chloride gradients). Density gradients are widely used for centrifugal and gravity induced separations of cells, organelles and macromolecules. The separations may exploit density differences between particles or primarily differences in size, in which latter case the function of the gradient is chiefly to stabilise the liquid column against mixing. (12 Jan 1998) |
| density gradient centrifugation | <technique> High-speed centrifugation inwhich molecules float at a point wheretheir density equals that in a gradient of cesium chloride or sucrose. (12 Jan 1998) |
| systolic gradient | The difference in pressure during systole between two communicating cardiovascular chambers, e.g., between the left ventricle and aorta in aortic stenosis. (05 Mar 2000) |
| ficoll gradient | A density gradient of ficoll (synthetic sucrose polymer) in solution, where concentration of the ficoll varies continuously through the solution. It is often used to separate different types of cells from each other during the process of sedimentation. (09 Oct 1997) |
| 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) |
| action potential | <physiology> The sequential, electrochemical polarization and depolarisation that travels across the membrane of a nerve cell (neuron) in response to stimulation (touch, pain, cold, etc.) (09 Oct 1997) |
| bioelectric potential | Electrical potential's occurring in living organisms. (05 Mar 2000) |
| biological hazard potential | <radiobiology> Measure of the hazard posed by a given quantity of radioactive material in which the variation in biological effects of the various elements are accounted for. See: integrated biological hazard potential. (21 Mar 1998) |
| biotic potential | <biology, ecology> The potential growth a population of living things can expect if it were living under ideal environmental circumstances. (19 Jan 1998) |
| body surface potential mapping | Recording of regional electrophysiological information by analysis of surface potentials to give a complete picture of the effects of the currents from the heart on the body surface. It has been applied to the diagnosis of old inferior myocardial infarction, localization of the bypass pathway in wolff-parkinson-white syndrome, recognition of ventricular hypertrophy, estimation of the size of a myocardial infarct, and the effects of different interventions designed to reduce infarct size. The limiting factor at present is the complexity of the recording and analysis, which requires 100 or more electrodes, sophisticated instrumentation, and dedicated personnel. (12 Dec 1998) |
| brain potential | <physiology> The electrical charge of the brain as compared to a point on the body; the potential may be steady (DC potential) or may fluctuate at specific frequencies when recorded against time, giving rise to the electroencephalogram. (05 Mar 2000) |
| pacemaker potential | The voltage inscribed by impulses from an artificial electronic pacemaker. (05 Mar 2000) |