concentration
1. A preparation made by extracting a crude drug, precipitating from the solution, and drying. 2. Increasing the amount of solute in a given volume of solution by evaporation of the solvent. 3. The quantity of a substance per unit volume or weight. In renal physiology, symbol U for urinary c., P for plasma c.; in respiratory physiology, symbol C for amount per unit volume in blood, F for fractional c. (mole fraction or volume per volume) in dried gas; subscripts indicate location and chemical species. [L. con-, together, + centrum, center]
- Baermann c. preparation that relies on the principle that active nematode larvae will migrate from a fresh fecal specimen through several layers of gauze into tap water, from which the larvae can be recovered by centrifugation.
- buffy coat c. centrifugation of whole blood containing anticoagulant to obtain a buffy coat layer containing white blood cells; blood films for staining can be prepared from this layer of cells and examined for the presence of parasites (trypanosomes and intracellular leishmaniae).
- critical micelle c. (cmc) the c. at which an amphipathic molecule ( E.G., a phospholipid) will form a micelle.
- fecal c. preparation using centrifugation and either flotation or sedimentation methods to separate parasitic elements from fecal debris.
- formalin-ether sedimentation c. a sedimentation method to separate parasitic elements from fecal debris through centrifugation and the use of ether to trap debris in a separate layer from the parasites.
- formalin-ethyl acetate sedimentation c. a sedimentation method to separate parasitic elements from fecal debris through centrifugation and the use of ethyl acetate (substitute for ether) to trap debris in a separate layer from the parasites.
- gravity c. a method of separating parasites from debris through gravity sedimentation of fecal suspensions.
- M c. the maximum number of bacterial cells which can be produced in a unit volume of growth medium.
- mean corpuscular hemoglobin c. (MCHC) Hgb/Hct; the average hemoglobin c. in a given volume of packed red cells, calculated from the hemoglobin therein and the hematocrit, in erythrocyte indices.
- microhematocrit c. the centrifugation of whole, anticoagulated blood, using microhematocrit tubes, to obtain a buffy coat layer containing white blood cells; blood films for staining can be prepared from this layer of cells and examined for the presence of parasites (trypanosomes and intracellular leishmaniae).
- minimal alveolar c. the end-alveolar c. of an inhalation anesthetic that prevents somatic response to a painful stimulus in 50% of individuals; an index of relative potency of inhalation anesthetics. SYN: minimal anesthetic c..
- minimal anesthetic c. (MAC) SYN: minimal alveolar c..
- minimal inhibitory c. (MIC) the lowest c. of antibiotic sufficient to inhibit bacterial growth when tested in vitro.
- molar c. molar (4).
- normal c. (n) normal (3).
- zinc sulfate flotation c. a method using saturated zinc sulfate to separate parasitic elements from fecal debris through differences in specific gravity; most parasite cysts, oocysts, spores, eggs, and larvae can be found in the surface film after centrifugation.

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con·cen·tra·tion .kän(t)-sən-'trā-shən, -.sen- n
1) the act or action of concentrating: as
a) a directing of the attention or of the mental faculties toward a single object
b) an increasing of strength (as of a solute or a gas in a mixture) or a purifying by partial or total removal of diluents, solvents, admixed gases, extraneous material, or waste (as by evaporation or diffusion)
2) a crude active principle of a vegetable esp. for pharmaceutical use in the form of a powder or resin
3) the relative content of a component (as dissolved or dispersed material) of a solution, mixture, or dispersion that may be expressed in percentage by weight or by volume, in parts per million, or in grams per liter

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con·cen·tra·tion (kon″sən-traґshən) [L. concentratio] 1. increase in strength by evaporation. 2. the ratio of the mass or volume of a solute to the mass or volume of the solution or solvent. Cf. molarity, molality, normality, and mole fraction.

Medical dictionary. 2011.

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  • concentration — [ kɔ̃sɑ̃trasjɔ̃ ] n. f. • 1732; de concentrer, d apr. l angl. 1 ♦ Action de concentrer, de réunir en un centre. ⇒ accumulation, assemblage, réunion. La concentration des rayons lumineux au foyer d une lentille. ⇒ convergence. Milit. La… …   Encyclopédie Universelle

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  • concentration — con‧cen‧tra‧tion [ˌkɒnsnˈtreɪʆn ǁ ˌkɑːn ] noun [uncountable] ECONOMICS when companies combine to form larger companies, resulting in fewer businesses in an industry; = CONSOLIDATION: • Continental, in a move that underlines the growing… …   Financial and business terms

  • Concentration — Con cen*tra tion, n. [Cf. F. concentration.] 1. The act or process of concentrating; the process of becoming concentrated, or the state of being concentrated; concentration. [1913 Webster] Concentration of the lunar beams. Boyle. [1913 Webster]… …   The Collaborative International Dictionary of English

  • Concentration 20 — Album par Namie Amuro Sortie 24 juillet 1997 Enregistrement Complex Studio, Larrabee West, Record Plant Studios, Sony Music Studio, tk sequence 1105st Durée 56:17 Genre …   Wikipédia en Français

  • concentration — CONCENTRATION. s. f. Terme didactique. L action de concentrer, ou l effet de ce qui est concentré. La concentration de la chaleur.Concentration, en termes de Chimie, se dit d Une opération, par laquelle on rapproche sous un moindre volume les… …   Dictionnaire de l'Académie Française 1798

  • concentration — I (centralization) noun agglomeration, aggregation, assemblage, collection, combination, compilation, confluence, contemplation, cumulation, density, horde, immersion II (compression) noun absorption, accumulation, agglomeration, amassment,… …   Law dictionary

  • concentration — [n1] consolidation of effort absorption, amassing, application, assembly, bringing to bear, centering, centralization, close attention, clustering, coalescing, combination, compacting, compression, concern, congregation, consolidation,… …   New thesaurus

  • Concentration — Concentration. См. Концентрация. (Источник: «Металлы и сплавы. Справочник.» Под редакцией Ю.П. Солнцева; НПО Профессионал , НПО Мир и семья ; Санкт Петербург, 2003 г.) …   Словарь металлургических терминов

  • Concentration — (v. lat.), 1) das Zusammendrängen nach einer gemeinschaftlichen Mitte hin; 2) (Phys.), das Zusammendrängen von Lichtstrahlen auf einem Punkte od. engem Raum, vgl. Brennpunkt; 3) die Vereinigung wirksamer Theile einer Flüssigkeit in einem… …   Pierer's Universal-Lexikon

  • concentration — 1630s, action of bringing to a center, noun of action from verb CONCENTRATE (Cf. concentrate) (q.v.). Meaning a mass so collected is from 1670s; continuous focus of mental activity is from 1846 …   Etymology dictionary

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