| FPM | filter paper microscopic [test]; full passive movements |
|---|---|
| HEPA | high-efficiency particulate air [filter] |
| HPF | heparin-precipitable fraction; hepatic plasma flow; high-pass filter; high-power field [microscope];... |
| QMF | quadrature mirror filter |
| ULPA | ultra low penetration air filter |
| slow pyrolysis | Thermal conversion of biomass to fuel by slow heating to less than 450>C in the absence of oxygen. (05 Dec 1998) |
|---|---|
| slow ray | <microscopy> The slower of the two rays created by a crystal or fibre and the one that travels the path of higher refractive index. (05 Aug 1998) |
| slow-reacting factor of anaphylaxis | Slow-reacting substance of anaphylaxis (SRS-A), a leukotriene of low molecular weight which is released in anaphylactic shock and produces slower and more prolonged contraction of muscle than does histamine; it is active in the presence of antihistamines (but not epinephrine) and seems not to occur preformed in mast cells, but as a result of an antigen-antibody reaction on the granules. Compare: peptidyl leukotrienes. Synonym: slow-reacting factor of anaphylaxis. (05 Mar 2000) |
| slow-reacting substance | Slow-reacting substance of anaphylaxis (SRS-A), a leukotriene of low molecular weight which is released in anaphylactic shock and produces slower and more prolonged contraction of muscle than does histamine; it is active in the presence of antihistamines (but not epinephrine) and seems not to occur preformed in mast cells, but as a result of an antigen-antibody reaction on the granules. Compare: peptidyl leukotrienes. Synonym: slow-reacting factor of anaphylaxis. (05 Mar 2000) |
| slow reacting substance of anaphylaxis | <immunology> Potent bronchoconstrictor and inflammatory agent released by mast cells, an important mediator of allergic bronchial asthma. A mixture of three leukotrienes (LTC4 mainly, LTD4 and LTE4) (18 Nov 1997) |
| slow scan | <microscopy> A system of video scanning in which the time used to read each line has been increased in comparison to standard video. The bandwidth needed to faithfully transmit or record the signal is reduced in inverse ratio to the scanning time. Slow scan allows the video signal to be transmitted over a telephone line, or line scans to be registered on a chart recorder. (19 Jan 1998) |
| slow virus | 1. <virology> Specifically one of the Lentivirinae 2. Any virus causing a disease that has a very slow onset. Diseases such as sub acute spongiform encephalopathy, Aleutian disease of mink, scrapie, kuru and Creutzfeldt Jacob disease may be caused by slow viruses. See: prion. (18 Nov 1997) |
| slow virus disease | A disease that follows a slow, progressive course spanning months to years, frequently involving the central nervous system, and ultimately leading to death, such as visna and maedi of sheep, caused by viruses of the subfamily Lentivirinae (family Retroviridae), and subacute sclerosing panencephalitis, seemingly caused by the measles virus; spongiform encephalopathies including kuru of man, scrapie of sheep, and transmissible encephalopathy of mink may also be classified under slow virus disease but their respective aetiologic agents have not been adequately characterised. (05 Mar 2000) |
| slow virus diseases | Diseases of viral origin, characterised by incubation periods of months to years, insidious onset of clinical manifestations, and protracted clinical course. Though the disease process is protracted, viral multiplication may not be unusually slow. Conventional viruses produce slow virus diseases such as subacute sclerosing panencephalitis, progressive multifocal leukoencephalopathy (leukoencephalopathy, progressive multifocal), and aids. Diseases produced by unconventional agents were originally considered part of this group. They are now called prion diseases. (12 Dec 1998) |
| absolute filter | <apparatus> A fine-pored, steam-sterilisable filter that is used to trap airborne microorganisms. The filter's pores are about 2 micrometres in diameter, smaller than the particles it is designed to remove. (06 May 1997) |
| bandpass filter | A device that allows a limited range of frequencies to pass. (05 Mar 2000) |
| Berkefeld filter | A bacterial filter used in 1891, made of earth known as Kieselguhr taken from the name of the mine in Hanover, Germany, from which the earth was found. Ground water at this mine had a clear blue colour suggesting the use of the earth as a filter. Origin: Berkefield, name of owner of the mine from which the material to make the filter was taken (05 Mar 2000) |
| bird's nest filter | A wire mesh vena cava filter. (05 Mar 2000) |
| bird's nest ivc filter | <radiology> Introduced 1982; Cook Inc., Bloomington, IN advantages, low profile: 14.5 Fr introducer sheath, low recurrent PE rates (1.1 - 2.7% by clinical history), low IVC thrombosis rates (2.9 - 5.0% by clinical history), placement in large diameter IVCs (not greater than40mm), free-form configuration does not require centreing in IVC disadvantages: stainless steel: ferromagnetic = magnetic susceptibility artifact, more operator dependent, difficult to place in short IVCs (need about 7cm for proper placement), prolapse of filter wires (? clinical significance) see also: indications (12 Dec 1998) |
| vena cava filter | A filter used for interruption of IVC to prevent pulmonary embolism; e.g., Greenfield filter. Synonym: venocaval filter. (05 Mar 2000) |