| PE tube | Polyethylene Ventilating tube placed in the eardrum |
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| SB tube | Sengstaken-Blakemore tube |
| ET | educational therapy; effective temperature; ejection time; embryo transfer; endothelin; endotoxin; e... |
| OET | oral endotracheal tube; oral esophageal tube |
| TT | tablet triturate; tactile tension; tendon transfer; test tube; testicular torsion; tetanus toxin; te... |
| emission | 1. The act of sending or throwing out; the act of sending forth or putting into circulation; issue; as, the emission of light from the sun; the emission of heat from a fire; the emission of bank notes. 2. That which is sent out, issued, or put in circulation at one time; issue; as, the emission was mostly blood. 3. <physics> Emission theory, the theory of Newton, regarding light as consisting of emitted particles or corpuscles. See Corpuscular theory. Origin: L. Emissio: cf. F. Emission. Source: Websters Dictionary (01 Mar 1998) |
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| emission-computed tomography | <radiology> Tomography using emissions from radionuclides and a computer algorithm to reconstruct the image. (20 Jun 2000) |
| emission electron | <physics>? A beta particle resulting from radioactive decay. (05 Mar 2000) |
| emission offset | <chest medicine> A reduction in the air pollution emissions of existing sources to compensate for emissions from new sources. (05 Dec 1998) |
| emission standard | This regulatory value is a quantitative limit on the emission or discharge of a potentially toxic substance from a source. The simplest form for regulatory purposes is a uniform emission standard (UES) where the same limit is placed on all emissions of a particular contaminant. (09 Oct 1997) |
| flame emission spectrophotometry | Determination of the concentration of an element by measurement of light emitted when the element is excited by energy in the form of heat. (05 Mar 2000) |
| auditory field | The space included within the limits of hearing of a definite sound, as of a tuning fork. (05 Mar 2000) |
| bright field illumination | <microscopy> The method of lighting the specimen with a solid cone of rays. Transmitted bright field illumination is performed by a substage condenser. Reflected bright field illumination is performed by a vertical illuminator. Compare: dark field illumination (05 Aug 1998) |
| bright field imaging | <microscopy> An imaging mode in a transmission electron microscopy that uses only unscattered Electrons to form the image. Contrast in such an image is due entirely to mass-thickness variations in amorphous samples, and may include diffraction contrast in crystalline samples. (05 Aug 1998) |
| bright field microscopy | <technique> Optical microscopy, in which absorption to a great extent and diffraction to a minor extent give rise to the image, as opposed to phase contrast or interference methods of microscopy. (18 Nov 1997) |
| Broca's field | The posterior part of the inferior frontal gyrus of the left or dominant hemisphere, corresponding approximately to Brodmann's area 44; Broca identified this region as an essential component of the motor mechanisms governing articulated speech. Synonym: Broca's area, Broca's field, motor speech centre. (05 Mar 2000) |
| cardioid dark field condenser | <microscopy> A condenser designed with two reflecting surfaces, the first, a spherical surface which reflects the rays to a second, cardioid (heart-shaped) surface. The virtue in such an arrangement is that, if the cardioid surface is of true figure, the lens is both achromatic and aplanatic. It has a limiting numerical aperture of about 1.0. Thus objectives of a greater numerical aperture cannot be used successfully with it. A true cardioid figure is the trace of a point on the circumference of a circle rolling around an equal, fixed circle. (05 Aug 1998) |
| magnetic field | The sphere of influence of a magnet. (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) |
| paraboloid dark field condenser | <microscopy> A lens of parabolic shape. The vertex end is ground back so that its focus can be brought into coincidence with the specimen on the slide. A central stop is provided to block the central rays. It is used chiefly for medium- power work. (05 Aug 1998) |