| Dp | pattern difference |
|---|---|
| EEGV1 | electroencephalographic variant pattern 1 |
| MCP | maximum closure pressure; maximum contraction pattern; malanocortin receptor; melphalan, cyclophosph... |
| MCPP | metacarpophalangeal pattern profile; metacarpophalangeal profile; meta-chlorophenylpiperazine |
| MCPPP | metacarpophalangeal pattern profile plot |
| three-dimensional diffraction pattern | <optics> The diffraction pattern (of a point source) that appears in the three-dimensional space in and near the focal plane. For an aberration-free, diffraction- limited system, the slice of the diffraction pattern in the focal plane is the Airy disk and its surrounding diffraction rings. Above and below focus, the pattern changes periodically along the axis of the light beam so that bright and dark Airy-disk-like patterns appear alternately. The axial period of repeat is spaced twice as far apart as the radial period of repeat in the Airy disk and its diffraction rings (05 Aug 1998) |
|---|---|
| juvenile pattern | A precordial T-wave inversion, sometimes with J-ST elevations in an electrocardiogram, resembling that seen in normal children, which occurs as a normal variant in some adults, especially blacks, and especially in leads V1, V2, and V3. (05 Mar 2000) |
| female pattern alopecia | Diffuse partial hair loss in the centroparietal area of the scalp, with preservation of the frontal and temporal hair lines; the most frequent type of androgenic alopecia in women. (05 Mar 2000) |
| female pattern baldness | <dermatology> Hair loss in women that may be associated with aging, hormones (androgens) or genetic predisposition. The pattern of baldness in women is different from that of men. In women there is thinning of the hair all over the scalp, but the frontal hairline is maintained. The hair loss is usually permanent. Treatment has been successful with topical minoxidil in some cases. (27 Sep 1997) |
| aperture for electron microscopy | <technique> Anode aperture: The opening in the accelerating voltage anode shield of the electron gun through which the electrons must pass to irradiate the specimen. Condenser aperture: An opening in the condenser lens controlling the number of electrons entering the lens and the angular aperture of the electron beam. The angular aperture can also be controlled by the condenser lens current. Physical objective aperture: A metallic diaphragm, with a small central hole, used to limit the cone of electrons accepted by the objective lens. This improves image-contrast since highly scattered electrons are prevented from arriving at the Gaussian image plane and therefore cannot contribute to background fog. Aplanatic. Free from spherical aberration and coma. (05 Aug 1998) |
| Auger electron | An electron ejected from a lower energy orbital after a photoelectric interaction of an X-ray photon with a K-shell electron by the characteristic radiation photon; the Auger electron recoils with energy equal to the characteristic radiation less the difference in shell binding energies. See: photoelectric effect. (05 Mar 2000) |
| backscattered electron | <microscopy> Produced by an incident electron colliding with the nucleus of an atom in the specimen. The incident electron is then scattered backward about 180 degrees with no appreciable loss of energy, an elastic collision. (05 Aug 1998) |
| backscattered electron imaging | <microscopy> The production of backscattered electrons from a sample varies directly with the specimen's average atomic number, higher atomic number elements produce more backscattered electrons than lower atomic number ones. Detection of Backscattered Electrons is achieved by using a donut shaped solid state saemiconductor device mounted on the bottom of the objective lens. When Backscattered Electrons strike the detector electron-hole pairs are created which are then counted. This quantity is translated into a pixel intensity and displayed on the CRT, forming the image. By splitting the detector into halves (or quadrants) differences in the signal level on the individual detector segments provide surface topography information. (05 Aug 1998) |
| valence electron | One of the electron's that take part in chemical reactions of an atom. (05 Mar 2000) |
| Parallel Electron Energy Loss Spectroscopy | <technique> Electron energy loss spectroscopy analyses the inelastically scattered electrons present in the beam after it has been transmitted through the sample. An electron energy loss spectrum typically consists of a monatomic decreasing background on which are superimposed a number of peaks. Each peak is characteristic of the scattering process that has occurred in the sample. The peaks can be used to obtain information about the chemical composition and electronic structure of the sample. Electron energy loss spectra are acquired typically in a magnetic sector spectrometer located under the camera chamber of the transmission electron microscope. Spatial resolution is typically limited by the minimum probe diameter of the microscope. Electron energy loss spectroscopy tends to be complimentary to EDS in that it can be used to analyse very thin samples of low Z materials. Acronym: PEELS (05 Aug 1998) |
| reverse electron transport | <chemistry> The energy-dependent movement of electrons against the thermodynamic gradient to form a strong reductant from a weaker electron donor. (11 Jan 1998) |
| microscope, electron | <microscopy> An electron-optical device which produces a magnified image of an object. Detail may be revealed by virtue of selective transmission, reflection, or emission of electrons by the object. (05 Aug 1998) |
| microscopy, electron | Visual and photographic microscopy in which electron beams with wavelengths thousands of times shorter than visible light are used in place of light, thereby allowing much greater magnification. (12 Dec 1998) |
| microscopy, electron, scanning | Microscopy in which the object is examined directly by an electron beam scanning the specimen point-by-point, giving the surface image a three-dimensional quality. (12 Dec 1998) |
| microscopy, electron, scanning transmission | A type of electron microscopy which scans with an extremely narrow beam that is transmitted through the sample. The detection apparatus produces an image whose brightness depends on the atomic number of the sample. It should not be confused with microscopy, electron scanning nor with microscopy, electron, transmission (see microscopy, electron). (12 Dec 1998) |