| GA | Gamblers Anonymous; gastric analysis; gastric antrum; general anesthesia; general angiography; gener... |
|---|---|
| IAA | imidazoleacetic acid; indoleacetic acid; infectious agent, arthritis; insulin autoantibody; Internat... |
| NA | Avogadro constant or number; nalidixic acid; Narcotics Anonymous; network administrator; neuraminida... |
| NAA | N-acetyl aspartate; naphthaleneacetic acid; neutral amino acid; neutron activation analysis; neutrop... |
| TCA | T-cell A locus; terminal cancer; tetracyclic antidepressant; total cholic acid; total circulating al... |
| feedback regulation | <physiology> Control mechanism that uses the consequences of a process to regulate the rate at which the process occurs: if, for example: the products of a reaction inhibit the reaction from proceeding (or slow down the rate of the reaction), then there is negative feedback, something that is very common in metabolic pathways. Positive feedback is liable to lead to exponential increase and may be explosively dangerous in some cases. Other examples are the action of voltage dependent sodium channels in generating action potentials and the activation of blood clotting factors V and VIII by thrombin. Without damping, feedback can lead to resonance (hunting) and oscillation in the system. (18 Nov 1997) |
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| up-regulation | Opposite of down-regulation. (05 Mar 2000) |
| up-regulation (physiology) | Process that increases ligand/receptor interactions due to an increase in the number of available receptors. (12 Dec 1998) |
| acrylic resin base | A form made of acrylic resin molded to conform to the tissues of the alveolar process and used to support the teeth of a prosthesis. (05 Mar 2000) |
| aldehyde base | An obsolete term for an imide. (05 Mar 2000) |
| anterior cranial base | The portion of the internal base of the skull, anterior to the sphenoidal ridges and limbus, in which the frontal lobes of the brain rest. Synonym: fossa cranii anterior, anterior cranial base. (05 Mar 2000) |
| Bandrowski's base | <chemical> Reported cause of anaphylactic reaction. Synonym: n',n'-bis(4-aminophenyl)-2,5-diamino-1,4-quinonediimine (26 Jun 1999) |
| base | <chemistry> The nonacid part of a salt, a substance that combines with acids to form salts, a substance that dissociates to give hydroxide ions in aqueous solutions, a substance whose molecule or ion can combine with a proton (hydrogen ion), a substance capable of donating a pair of electrons (to an acid) for the formation of a coordinate covalent bond. (13 Nov 1997) |
| base analogue | <biochemistry> A chemical which resembles a nucleotide base. They can substitute the Purine and pyrimidine bases that normally appear in DNA, despite minor differences in structure. May be used for inducing mutations, including point mutations. For example: 5 bromouracil can replace thymine or 2 aminopurine replace adenine. (13 Nov 1997) |
| base composition | <biochemistry> In reference to nucleic acid, the proportion of the total bases consisting of guanine plus cytosine or thymine plus adenine base pairs. Usually expressed as a guanine + cytosine (G+C) value, for example 60% G+C. (09 Oct 1997) |
| base deficit | A decrease in the total concentration of blood buffer base, indicative of metabolic acidosis or compensated respiratory alkalosis. (05 Mar 2000) |
| base dissociation constant | <chemistry> This is the equilibrium constant for the reaction in which a weak base breaks apart in water to form its conjugate acid and hydroxide ion. (09 Oct 1997) |
| base excess | A measure of metabolic alkalosis, usually predicted from the Siggaard-Andersen nomogram; the amount of strong acid that would have to be added per unit volume of whole blood to titrate it to pH 7.4 while at 37캜 and at a carbon dioxide pressure of 40 mm Hg. (05 Mar 2000) |
| base hospital | A hospital unit located in a military or recreational encampment; usually of small size and limited facilities, for immediate care of illnesses and injuries. Synonym: camp hospital. (05 Mar 2000) |
| base in DNA | A unit of the DNA. There are 4 bases: adenine (A), guanine (G), thymine (T), and cytosine (C). The sequence of bases (for example, CAG) is the genetic code. (12 Dec 1998) |