| IPD | idiopathic Parkinson disease; idiopathic protracted diarrhea; immediate pigment darkening; increase ... |
|---|---|
| IPG | impedance plethysmography; inspiration-phase gas |
| LEP | lethal effective phase; lipoprotein electrophoresis; low egg passage; lower esophagus |
| LLP | late luteal phase; long-lasting potentiation |
| LPD | low-protein diet; luteal phase defect |
| phase encoding | In magnetic resonance imaging, the technique of inducing a gradient in the magnetic field in the Y-axis to induce phase differences with location. Synonym: gradient encoding. (05 Mar 2000) |
|---|---|
| phase I block | Inhibition of nerve impulse transmission across the myoneural junction associated with depolarisation of the motor endplate, as in the muscle paralysis produced by succinylcholine. (05 Mar 2000) |
| phase II block | Inhibition of nerve impulse transmission across the myoneural junction unaccompanied by depolarisation of the motor endplate, as in the muscle paralysis produced by tubocurarine. (05 Mar 2000) |
| phase image | A magnetic resonance image showing only phase shift information, to detect motion. (05 Mar 2000) |
| phase plate | <microscopy> The plate used near the back focal plane of a microscope objective lens (in conjunction with an annulus at the front focal plane of the condenser lens) to achieve phase contrast. The phase plate selectively shifts the phase of the waves diffracted by the specimen by a quarter wave and reduces the amplitude of the undeviated, direct beam. (05 Aug 1998) |
| phase, resting | More appropriately called interphase. The interval in the cell cycle between two cell divisions when the individual chromosomes cannot be distinguished, interphase was once thought to be the resting phase but it is far from a time of rest for the cell. It is the time when DNA is replicated in the cell nucleus. (12 Dec 1998) |
| phase rule | An expression of the relationships existing between systems in equilibrium: P + V = C + 2, where P is the number of phases, V the variance or degrees of freedom, and C the number of components; it also follows that the variance is, V = C + 2 -P. For H2O at its triple point, V = 1 + 2 -3 = 0, i.e., both temperature and pressure are fixed. Synonym: Gibb's phase rule. (05 Mar 2000) |
| phase separation | <chemistry> The separation of fluid phases that contain different concentrations of common components. Occurs with partially miscible solvents used in many biochemical separation methods. Also temperature dependent phase separation occurs with some detergent solutions. With reference to membranes means the segregation of lipid components into domains that have different chemical composition. (31 Dec 1997) |
| phase shift | <microscopy> A change in the phase relationship between two alternating quantities of the same frequency. (05 Aug 1998) |
| phase variation | <microbiology> Alteration in the expression of surface antigens by bacteria. For example: Salmonella can express either of two forms of flagellin, H1 and H2, that are coded by different genes. Control of which form is expressed is brought about by inversion of the promoter for the H2 gene, which if functional (noninverted) is associated with the expression of H2 and the production of a repressor of the H1 gene. Inversion occurs about every 1000 bacterial divisions and is under the control of another gene, hin, that is within the invertable sequence. (31 Dec 1997) |
| chronic phase | Refers to the early stages of chronic myelogenous leukaemia. The number of immature, abnormal white blood cells in the bone marrow and blood is higher than normal, but lower than in the accelerated or blast phase. (12 Dec 1998) |
| microscopy, phase-contrast | A form of interference microscopy in which variations of the refracting index in the object are converted into variations of intensity in the image. This is achieved by the action of a phase plate. (12 Dec 1998) |
| M phase | Mitotic phase of cell cycle of eukaryotic cells, as distinct from the remainder, which is known as interphase (and that can be further subdivided as G1, s and G2). Beginning of M is signalled by separation of centrioles, where present and by the condensation of chromatin into chromosomes. M phase ends with the establishment of nuclear membranes around the two daughter nuclei, normally followed immediately by cell division (cytokinesis). (18 Nov 1997) |
| M phase promoting factor | Protein whose levels rise rapidly just before and fall away just after, mitosis. Thought to be a trigger for mitosis. (18 Nov 1997) |
| plateau phase | <oncology> Stable stage of disease in multiple myeloma following good response to anti-cancer treatment. (31 Dec 1997) |