| point mutation | <molecular biology> Mutation that causes the replacement of a single base pair with another pair. (18 Nov 1997) |
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| point-of-care systems | Laboratory and other services provided to patients at the bedside. These include diagnostic and laboratory testing using automated information entry systems. (12 Dec 1998) |
| point of elbow | <anatomy> The large process at the proximal end of the ulna which projects behind the articulation with the humerus and forms the bony prominence of the elbow. Origin: NL, fr.Gr.; elbow + the head. Source: Websters Dictionary (01 Mar 1998) |
| point of fixation | The point on the retina at which the rays coming from an object regarded directly are focused. Synonym: point of regard. (05 Mar 2000) |
| point of maximal impulse | The point on the chest wall at which the maximal cardiac impulse is seen and/or felt. (05 Mar 2000) |
| point of ossification | The site of earliest bone formation via accumulation of osteoblasts within connective tissue (membranous ossification) or of earliest destruction of cartilage prior to onset of ossification (endochondral ossification). Synonym: punctum ossificationis, ossific centre, point of ossification. (05 Mar 2000) |
| point of proximal contact | That part of the proximal surface of a tooth which touches the adjacent tooth mesially or distally. Synonym: contact point, point of proximal contact. (05 Mar 2000) |
| point of regard | The point on the retina at which the rays coming from an object regarded directly are focused. Synonym: point of regard. (05 Mar 2000) |
| point projection | <microscopy> A method of producing enlarged images by means of X rays. The specimen is placed close to a point source of X rays and the magnification achieved is the ratio of source-image to source-object distance. Resolution depends primarily on the diameter of the source. (05 Aug 1998) |
| point source | In photometry, a very small source of light which is regarded as a geometrical point from which light emanates in straight lines in all directions. (05 Mar 2000) |
| point-spread function | <microscopy> The mathematical representation of the image of a point source. For a diffraction-limited optical system operating in the absence of aberrations, the point-spread function is the Airy disk. See: three-dimensional diffraction pattern. (05 Aug 1998) |
| point system test types | A near-vision test chart in which the various test types are multiples of a point (1/72 inch), lower-case letters being one-half the designated point size; reading 4-point at 16 inches is normal, and is designated N-4. (05 Mar 2000) |
| point tenderness | <clinical sign> A finding on physical examination that can indicate a localised inflammatory process due to injury or disease. Point tenderness will be discovered over fracture sites (in bone injury). (27 Sep 1997) |
| critical point | A point at which two phases become identical; thus, at a given critical temperature and critical pressure, the liquid and gaseous state of a particular substance can no longer be differentiated. (05 Mar 2000) |
| critical point drying | <procedure> A method for preparing specimens for the scanning electron microscope that avoids the problems of shrinkage caused by normal drying procedures. Water in the specimen is replaced by an intermediate fluid, for example liquid carbon dioxide, avoiding setting up a liquid/gas interface and then the second fluid is allowed to vaporise by raising the temperature above the critical point, the temperature at which the liquid state no longer occurs. (18 Nov 1997) |