| biological specimen banks | Centres for collecting, storing, and distributing human or other animal material or tissues for future use by other individuals, as blood banks, bone banks, eye banks, milk banks, skin banks, sperm banks, and tissue banks. (12 Dec 1998) |
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| biological standard unit | A specific quantity of biologically active reference material (antibiotic, antitoxin, enzyme, hormone, vitamin, etc.). (05 Mar 2000) |
| biological therapy | <oncology> Treatment with substances that can stimulate the immune system to fight disease more effectively. Synonym: immunotherapy. (16 Dec 1997) |
| biological transport | The movement of materials (including biochemical substances and drugs) across cell membranes and epithelial layers, usually by passive diffusion. (12 Dec 1998) |
| biological transport, active | The movement of materials across cell membranes and epithelial layers against an electrochemical gradient, requiring the expenditure of metabolic energy. (12 Dec 1998) |
| biological value | <nutrition> The nutritional value of a protein, usually measured in comparison to the nutritional value of egg protein, which is the highest possible (BV=0.9 - 1.00). (21 Mar 1998) |
| biological vector | A vector, such as the Anopheles mosquito for malarial agents or the tsetse fly for agents of African sleeping sickness, in which the agent multiplies prior to being transmitted to another host. (05 Mar 2000) |
| biological warfare | <microbiology> The military use of harmful biological agents such as pathogenic bacteria. (21 Mar 1998) |
| relative biological effectiveness | The ratio of radiation dosages required to produce identical change based on a formula comparing other types of radiation with that of gamma or roentgen rays. (12 Dec 1998) |
| pest control, biological | The use of biological mechanisms, usually involving living organisms such as bacteria, for the reduction or regulation of the population of noxious, destructive, or dangerous pests. Environmental concerns have focused attention on natural forms of disease control as potentially safe and effective alternatives to chemical pesticides. This has led to increased efforts to develop control strategies that rely on natural predators and parasites or that involve genetically engineered microbial pest control agents. (12 Dec 1998) |
| models, biological | Theoretical representations that simulate the behaviour or activity of biological processes or diseases. For disease models in living animals, disease models, animal is available. Biological models include the use of mathematical equations, computers, and other electronic equipment. (12 Dec 1998) |
| immunologic and biological factors | A collective grouping for biologically active substances that play a role in the functioning of the immune system and those that show biological or physiological activity. (12 Dec 1998) |
| integrated biological hazard potential | <radiobiology> Total biological hazard potential of a collection of radioactive materials summed over their decay lifetimes. One measure of the integrated biological hazard potential is the amount of water one would need to use to dilute the materials to the point where the water would be safe to drink. (09 Oct 1997) |
| 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) |