| BaFBr:Eu | europium-activated barium fluorohalide |
|---|---|
| BaM | barium meal |
| BaS | barium swallow |
| BE | bacillary emulsion; bacterial endocarditis; barium enema; Barrett's esophagus; base excess; below-el... |
| BM | Bachelor of Medicine; barium meal; basal medium; basal metabolism; basement membrane; basilar membra... |
| unconsolidated parent material | <ecology> Material from which a soil develops. (09 Oct 1997) |
|---|---|
| fertile material | <physics> In nuclear physics, this refers to a nuclide which converts to fissile material upon neutron capture and subsequent radioactive decay. Examples include Uranium-238 and Thorium-232. (09 Oct 1997) |
| fill material | Any material used for the primary purpose of replacing an aquatic area with dry land or of changing the bottom elevation of a waterbody. The term does not include any pollutant discharged into the water primarily to dispose of waste. (09 Oct 1997) |
| fissile material | <radiobiology> Material containing a large number of easily fissionable nuclei which give off multiple neutrons in the fission process. Usual meaning is that if a sufficiently large amount of fissile material is put together, a fission chain reaction can occur. Sometimes used synonymously with fissionable material, i.e., material that can be fissioned (though often under restricted circumstances, such as only with thermal (slow) neutrons). A more restricted meaning use of fissile material limits the concept to those materials which can be fissioned by neutrons of all energies (fast & slow). Examples include Uranium-235 and Plutonium-239. (09 Oct 1997) |
| air contrast enema | A double contrast enema in which air is introduced after coating of the colon with a dense barium suspension for radiographic study. Synonym: air contrast barium enema. (05 Mar 2000) |
| Allen video enhanced contrast | <procedure> A method for enhancing microscopic images pioneered by R D Allen. The digitised image has the background (an out of focus image of the same microscopic field with comparable unevenness of illumination etc.) subtracted and the contrast expanded to utilise the potential contrast range. Interestingly, it is possible to produce images of objects that are below the theoretical limit of resolution microtubules for example. (18 Nov 1997) |
| radiopaque contrast | A radiopaque substance (for example metal) will be highlighted (appear white) on a plain X-ray. The use of iodine containing radiopaque contrast dyes allow enhancement of the anatomy demonstrable with conventional X-ray. (27 Sep 1997) |
| radiopaque contrast dye | A radiopaque substance (for example metal) will be highlighted (appear white) on a plain X-ray. The use of iodine containing radiopaque contrast dyes allow enhancement of the anatomy demonstrable with conventional X-ray. (27 Sep 1997) |
| phase-amplitude contrast | <microscopy> The separation and recombination of direct vs. Diffracted rays in a light microscope adjusted to Kohler illumination. at the lower focal plane of the condenser there is an annular diaphragm with an opaque central stop. Through this diaphragm rays are focused as a hollow cone onto the specimen. In the back focal plane of the objective there is a conjugate annular diaphragm (phase plate). If here the undiffracted rays are retarded (by a transparent film of proper thickness on the annulus of the phase plate), bright contrast results. If, instead, the phase-delay film is on the central spot, dark contrast results. With either a bright or a dark-contrast phase plate, the annulus is usually coated with a partially absorbing (very thin) film of silver (Zernike method) or carbon soot (Wilska method) to reduce the higher amplitude (intensity) of the undiffracted rays. (05 Aug 1998) |
| phase contrast | <microscopy> An optical method devised by F. Zernike for converting the focused image of a phase object (one with differences in refractive index or optical path but not in absorbance), which ordinarily is not visible in focus, into an image with good contrast. (05 Aug 1998) |
| phase-contrast microscope | <instrument> A specially constructed microscope that has a special condenser and objective containing a phase-shifting ring whereby small differences in index of refraction are made visible as intensity or contrast differences in the image; particularly useful for examining structural details in transparent specimens such as living or unstained cells and tissues. (05 Mar 2000) |
| phase contrast microscopy | <investigation> A simple nonquantitative form of interference micoscopy of great utility in visualising live cells. Small differences in optical path length due to differences in refractive index and thickness of structures are visualised as differences in light intensity. (18 Nov 1997) |
| 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) |
| colour-contrast microscope | <instrument> A type of microscope in which the condenser stop is of one colour and the annulus is a complement of it so that unstained objects are observed in one colour on a field of the other. (05 Mar 2000) |
| contrast | A dye injected intravenously during X-ray studies, for example CT, to enhance the image of a tumour. In MR studies, the contrast is called gadolinium. The use of contrast may rarely result in some adverse effects: it also increases the cost (but also accuracy in many cases) of the scan. (16 Dec 1997) |