| activated clotting time | The most common test used for coagulation time in cardiovascular surgery. (05 Mar 2000) |
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| activated complex | <chemistry> State of highest energy during a reaction. When reactants form the activated complex, bond breaking and bond formation is occurring. Synonym: transition state. (09 Jan 1998) |
| activated fatty acid | A fatty acyl-coenzyme A thiol ester. (05 Mar 2000) |
| activated glucose | A nucleoside diphosphoglucose such as UDP glucose. (05 Mar 2000) |
| activated macrophage | A mature macrophage, in an active metabolic state, that is cytotoxic to tumour/target cells, usually following exposure to certain cytokines. Synonym: armed macrophage. (05 Mar 2000) |
| activated partial thromboplastin time | The time needed for plasma to form a fibrin clot following the addition of calcium and a phospholipid reagent; used to evaluate the intrinsic clotting system. (05 Mar 2000) |
| activated resin | Autopolymerizing resin, any resin that can be polymerised by chemical catalysis rather than by the application of heat; used in dentistry for dental restoration, denture repair, and impression trays. Synonym: activated resin, cold cure resin, cold-curing resin, quick cure resin, self-curing resin. (05 Mar 2000) |
| activated sludge | See: activated sludge method. (05 Mar 2000) |
| activated sludge method | A method of sewage disposal in which the sewage is treated with 15% bacterially active, liquid sludge, which is produced by repeated vigorous aeration of fresh sewage to form floccules or sediment; when this flocculation process is complete, the resulting activated sludge contains large numbers of bacteria, together with yeasts, molds, and protozoa, which actively effect the oxidation of organic compounds; this mixture is piped to a sedimentation tank, the effluent from which is completely treated sewage. (05 Mar 2000) |
| activated sludge process | <procedure> A method of treating sewage and wastewater through microbial oxidation. Sewage previously treated in settling tanks is aerated to encourage the growth of nonpathogenic aerobic microorganisms (bacteria, yeasts, moulds and protozoans) which break the organic matter down into carbon dioxide, water and simple salts. After this activated sludge is produced, the wastewater undergoes further processing through anaerobic digestion, filtering and chlorination. (29 Dec 1997) |
| activated state | <chemistry, radiobiology> An atom or nucleus which possesses more energy than its ground state energy. (16 Dec 1997) |
| activation | <radiobiology> Activation occurs when a particle interacts with an atomic nucleus, shifting the nucleus into an unstable state, and causing it to become radioactive. In fusion research, where deuterium-tritium is a common fuel mixture, the neutron released when (D + T) combine to form (4He + n) can activate the reactor structure. In this case the 4He is inert, the neutron sticks to another nucleus, and the neutron + nucleus reaction creates an actvation product. Sometimes called radioactivation. See: activation product, activation analysis. (09 Oct 1997) |
| activation analysis | <radiobiology> Method for identifying and measuring chemical elements in a sample of material. Sample is first made radioactive by bombardment with neutrons, charged particles, or gamma rays. Newly formed radioactive atoms in the sample then give off characteristic radiations (such as gamma rays) that tell what kinds of atoms are present, and how many. (09 Oct 1997) |
| activation energy | <chemistry> The amount of energy (expressed in joules) that is needed to convert all the molecules in one mole of a reacting substance from a ground state to the transition state. (06 May 1997) |
| activation product | <radiobiology> The unstable nucleus formed when activation occurs. (See activation above.) (09 Oct 1997) |