| open reading frame | <molecular biology> A reading frame in a sequence of nucleotides in DNA that contains no termination codons and so can potentially translate as a polypeptide chain. (18 Nov 1997) |
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| open reading frames | Reading frames where successive nucleotide triplets can be read as codons specifying amino acids and where the sequence of these triplets is not interrupted by stop codons. (12 Dec 1998) |
| open reduction of fractures | Reduction by manipulation of bone, after incision in skin and muscle over the site of the fracture. (05 Mar 2000) |
| open skull fracture | A fracture with laceration of overlying scalp and/or mucous membrane. Synonym: compound skull fracture. (05 Mar 2000) |
| open system | A system that exchanges energy and materials with the outside environment. (09 Oct 1997) |
| open tuberculosis | Pulmonary tuberculosis, tuberculous ulceration, or other form in which the tubercle bacilli are present in the excretions or secretions; in the lung, usually the result of cavity formation. (05 Mar 2000) |
| open wound | A wound in which the tissues are exposed to the air. (05 Mar 2000) |
| fractures, open | Fractures in which there is an external wound communicating with the break of the bone. (12 Dec 1998) |
| Abbe test plate | <equipment> A long, wedge-shaped coverslip about 0.20 mm thick at one end and 0.10 to 0.12 mm at the other end coated chemically with a silver film on which are ruled horizontal lines. at each variation in thickness of 0.01 mm there are vertical lines. By means of oblique illumination and by focusing on different portions of the plate, it is possible to determine the optimum coverslip thickness for any objective and also, for microscopes with drawtubes, the tube length for best objective performance. The approximate freedom from spherical and chromatic aberrations can also be estimated. Small isolated bits of silver near the edges of the lines form good objects for the star test (05 Aug 1998) |
| acetone test | A test for ketonuria; the suspected urine is shaken up with a few drops of sodium nitroprusside, and strong ammonia water is then gently poured over the mixture; if acetone is present, a magenta ring forms at the line of contact; tablets containing sodium nitroprusside and alkali are now more commonly used. (05 Mar 2000) |
| achievement test | A standardised test used to measure acquired learning, e.g., competence in a specific subject area such as reading or arithmetic, in contrast to an intelligence test which is a useful index of potential ability or learning. (05 Mar 2000) |
| acidified serum test | Lysis of the patient's red cells in acidified fresh serum, specific for paroxysmal nocturnal haemoglobinuria. Synonym: Ham's test. (05 Mar 2000) |
| acid loading test | <nephrology> This is a test used in the diagnosis of renal tubular acidosis. The patient takes ammonium chloride capsules for 3 days to acidify the blood (lower blood pH). A sample of the urine and the blood is then collected and the results are interpreted. (27 Sep 1997) |
| acid perfusion test | <gastroenterology, investigation> A test used to diagnosis gastrooesophageal reflux disease. This investigation requires that the patient swallow 3 tiny tubes into the stomach. A mixture of hydrochloric acid (like stomach acid) and saline are alternatively injected into the tubes. The patient then reports any symptoms they may have. Some patients may vomit. (13 Nov 1997) |
| acid phosphatase test for semen | A screening test for semen by determining acid phosphatase content; because seminal fluid contains high concentrations of acid phosphatase, while other body fluids and extraneous foreign materials have very low concentrations, high values of acid phosphatase on vaginal aspirate or lavage, or on wash fluid from stains, render positive identification of semen, even if the male is aspermic. (05 Mar 2000) |