| DPA | Dual Photon Absorptiometry |
|---|---|
| DPX | Dual Photon X-Ray |
| SPA | 1) Single Photon Absorptiometry 2) Sperm Penetration Assay |
| SPECT | Single Photon Emission Computed Tomography = SET |
| EEP | end-expiratory pressure; equivalent effective photon |
| DPA | Dual Photon Absorptiometry |
|---|---|
| PCS | Photon Correlation Spectroscopy |
| PPF | Photosynthetic photon flux |
| SPA | Single Photon Absorptiometry |
| SPECT | Single Photon Emission CT |
| absorptiometry, photon | A noninvasive method for quantitating bone mineral content. It is used especially in the diagnosis of osteoporosis and also in measuring bone mineralization in infants. (12 Dec 1998) |
|---|---|
| photon | <physics> A quantum unit of light energy. (09 Oct 1997) |
| photon density | The number of counted events recorded in scintigraphy per square centimeter or per square inch of imaged area. Synonym: count density. (05 Mar 2000) |
| single photon emission computed tomography | <radiology> Tomographic imaging of metabolic and physiological functions in tissues, the image being formed by computer synthesis of photons of a single energy emitted by radionuclides administered in suitable form to the patient. The method uses radionuclides which emit a single photon of a given energy. The camera is then rotated 180 or 360 degrees around the patient to capture images at multiple positions along the arc. The computer then reconstructs the transaxial, sagittal, and coronal images from the 3-dimensional distribution of radionuclides in the target area scanned. The advantages of SPECT are that it can be used to observe biochemical and physiological processes as well as the size and volume of the organ. The disadvantage is that, unlike positron emission tomography where the positron-electron annihilation results in the emission of 2 photons at 180 degrees from each other, SPECT requires physical collimation to line up the photons, which results in the loss of available photons and hence degrades the image. Acronym: SPECT (20 Jun 2000) |
| axis, optical | <microscopy> Usually refers to the axis on which several principal lens axes may lie. It also refers to the axis of the eye which extends through the centre of the eye lens. The line formed by the coinciding principal axes of a series of optical elements comprising an optical system. It is the line passing through the centres of curvature of the optical surfaces. (05 Aug 1998) |
| specific optical dispersion | <microscopy> The difference between the refractive indices of light of two different wavelengths, both indices measured at the same temperature, the difference being divided by the specific gravity also measured in the same medium at the test temperature. For convenience, the specific dispersion value is multiplied by ten. (05 Aug 1998) |
| optical | 1. Of or pertaining to vision or sight. "The moon, whose orb Through optic glass the Tuscan artist views." (Milton) 2. Of or pertaining to the eye; ocular; as, the optic nerves (the first pair of cranial nerves) which are distributed to the retina. 3. Relating to the science of optics; as, optical works. <optics> Optic angle, a graduated circle used for the measurement of angles in optical experiments. Optical square, a surveyor's instrument with reflectors for laying off right angles. Origin: F. Optique, Gr.; akin to sight, I have seen, I shall see, and to the two eyes, face, L. Oculus eye. See Ocular, Eye, and cf. Canopy, Ophthalmia. Source: Websters Dictionary (01 Mar 1998) |
| optical aberration | Failure of rays from a point source to form a perfect image after traversing an optical system. (05 Mar 2000) |
| optical activity | The ability of a material to rotate the plane of polarized light. (09 Oct 1997) |
| optical antipode | <chemistry> A pair of chiral isomers (stereoisomers) that are direct, nonsuperimposable mirror images of each other. (09 Jan 1998) |
| optical axis | <physics> The line passing through both the centres of curvature of the optical surfaces of a lens, the optical centreline for all the centres of a lens system. (09 Oct 1997) |
| optical density | 1. <chemistry, investigation> Absorbance is defined as a logarithmic function of the percent transmission of a wavelength of light through a liquid. 2. <microbiology> This can be used as a measure of the amount of light absorbed by a suspension of bacterial cells or a solution of an organic molecule, it is measured by a colourimeter or spectrophotometer. Absorbance values are used to plot the growth of bacteria in suspension cultures and to gauge the purity and concentration of molecules (such as proteins) in solution. See: absorption. (15 Jan 1998) |
| optical diffraction | A technique used to obtain information about repeating patterns. Diffraction of visible light can be used to calculate spacings in the object. (18 Nov 1997) |
| optical flat | <microscopy> Usually, a glass or quartz plate or disk, the thickness of which should be at least 1/10 of its diameter. It is ground until any remaining unevenness can be measured only by interferometric methods. Their maximum departure from flatness usually is less than 1/10 of the sodium doublet (589.3 nm). (05 Aug 1998) |
| optical illusions | An illusion of vision usually affecting spatial relations. (12 Dec 1998) |
제품명 |
판매사 |
보험코드 | 성분/함량 | 구분/보험급여 |
|---|
제품명 |
판매사 |
보험코드 | 성분/함량 | 구분/보험급여 |
|---|