| post-steady state | Any period of time, particularly in an enzyme-catalyzed reaction, after the steady-state interval; e.g., when the rate of product formation is declining in an enzyme-catalyzed reaction. (05 Mar 2000) |
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| pre-steady state | Those conditions and the time interval prior to establishment of steady state. (05 Mar 2000) |
| steady state | A dynamic equilibrium. (13 Nov 1997) |
| steady-state rate | The velocity of an enzyme-catalyzed reaction in which, over the time course of the study, the concentration of any enzyme species is constant (i.e., for an enzyme-substrate binary complex, ES, d[ES]/dt&apprxeq;00; for this to hold true, the total enzyme concentration must be much less than the initial substrate concentration. Synonym: steady-state rate. (05 Mar 2000) |
| steady-state velocity | The velocity of an enzyme-catalyzed reaction in which, over the time course of the study, the concentration of any enzyme species is constant (i.e., for an enzyme-substrate binary complex, ES, d[ES]/dt&apprxeq;00; for this to hold true, the total enzyme concentration must be much less than the initial substrate concentration. Synonym: steady-state rate. (05 Mar 2000) |
| precession | The act of going before, or forward. Lunisolar precession. <astronomy> The slow backward motion of the equinoctial points along the ecliptic, at the rate of 50.2<sec/ annually, caused by the action of the sun, moon, and planets, upon the protuberant matter about the earth's equator, in connection with its diurnal rotation; so called because either equinox, owing to its westerly motion, comes to the meridian sooner each day than the point it would have occupied without the motion of precession, and thus precedes that point continually with reference to the time of transit and motion. Origin: L. Praecedere, praecessum, to go before: cf. F. Precession. See Precede. Source: Websters Dictionary (01 Mar 1998) |
| steady | 1. Firm in standing or position; not tottering or shaking; fixed; firm. "The softest, steadiest plume." "Their feet steady, their hands diligent, their eyes watchful, and their hearts resolute." (Sir P. Sidney) 2. Constant in feeling, purpose, or pursuit; not fickle, changeable, or wavering; not easily moved or persuaded to alter a purpose; resolute; as, a man steady in his principles, in his purpose, or in the pursuit of an object. 3. Regular; constant; undeviating; uniform; as, the steady course of the sun; a steady breeze of wind. Synonym: Fixed, regular, uniform, undeviating, invariable, unremitted, stable. <machinery> Steady rest, a rest in a turning lathe, to keep a long piece of work from trembling. Origin: Cf. AS. Stedig sterile, barren, staeig, steady (in gestaeig), D. Stedig, stadig, steeg, G. Statig, stetig. See Stead. Source: Websters Dictionary (01 Mar 1998) |
| acid-fast | <microbiology> A term used to denote bacteria that are not decolorised by acid-alcohol after having been stained with dyes such as basic fuchsin. The presence of acid fast organisms can be found in cultures that contain mycobacteria or some of the nocardiae. (12 Jul 2000) |
| acid-fast stain | <technique> A staining technique used to determine the cell wall property of a microorganism. After stained with dye such as hot carbolfuschin, an acid-fast organism, (for example Mycobacterium species) will retain the colour in its cell wall after being washed with acid-alcohol. (13 Nov 1997) |
| arsenic-fast | Resistant to the poisonous action of arsenic; denoting especially spirochetes and other protozoan parasites, which acquire resistance after repeated administration of the drug. (05 Mar 2000) |
| centrifugal fast analyzer | An automatic spectrophotometer that uses centrifugal force to mix samples and reagents, and propels the reactants at high speed about a detector that makes multiple absorbance readings. (05 Mar 2000) |
| Wassermann-fast | A term used to designate a case in which the Wassermann reaction remains positive despite all treatment. (05 Mar 2000) |
| histamine-fast | Indicating the absence of the normal response to histamine, especially in speaking of true gastric anacidity. (05 Mar 2000) |
| serum-fast | 1. Pertaining to a serum in which there is little or no change in the titre of antibody, even under conditions of treatment or immunologic stimulation. 2. Resistant to the destructive effect of sera. Synonym: serofast. (05 Mar 2000) |
| spectrometry, mass, fast atom bombardment | A mass spectrometric technique that is used for the analysis of a wide range of biomolecules, such as glycoalkaloids, glycoproteins, polysaccharides, and peptides. Positive and negative fast atom bombardment spectra are recorded on a mass spectrometer fitted with an atom gun with xenon as the customary beam. The mass spectra obtained contain molecular weight recognition as well as sequence information. (12 Dec 1998) |