| flow | 1. To move with a continual change of place among the particles or parts, as a fluid; to change place or circulate, as a liquid; as, rivers flow from springs and lakes; tears flow from the eyes. 2. To become liquid; to melt. "The mountains flowed down at thy presence." (Is. Lxiv. 3) 3. To pproceed; to issue forth; as, wealth flows from industry and economy. "Those thousand decencies that daily flow From all her words and actions." (Milton) 4. To glide along smoothly, without harshness or asperties; as, a flowing period; flowing numbers; to sound smoothly to the ear; to be uttered easily. "Virgil is sweet and flowingin his hexameters." (Dryden) 5. To have or be in abundance; to abound; to full, so as to run or flow over; to be copious. "In that day . . . The hills shall flow with milk." (Joel III. 18) "The exhilaration of a night that needed not the influence of the flowing bowl." (Prof. Wilson) 6. To hang loose and waving; as, a flowing mantle; flowing locks. "The imperial purple flowing in his train." (A. Hamilton) 7. To rise, as the tide; opposed to ebb; as, the tide flows twice in twenty-four hours. "The river hath thrice flowed, no ebb between." (Shak) 8. To discharge blood in excess from the uterus. Origin: AS. Flowan; akin to D. Vloeijen, OHG. Flawen to wash, Icel. Floa to deluge, Gr. To float, sail, and prob. Ultimately to E. Float, fleet. 80. Cf. Flood. 1. A stream of water or other fluid; a current; as, a flow of water; a flow of blood. 2. A continuous movement of something abundant; as, a flow of words. 3. Any gentle, gradual movement or procedure of thought, diction, music, or the like, resembling the quiet, steady movement of a river; a stream. "The feast of reason and the flow of soul." (Pope) 4. The tidal setting in of the water from the ocean to the shore. See Ebb and flow, under Ebb. 5. A low-lying piece of watery land; called also flow moss and flow bog. Source: Websters Dictionary (01 Mar 1998) |
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| flow cytoenzymology | A technique for for separating and sorting cells based on the presence ofspecific enzymes that create acoloured material when they bind to a substrate. (09 Oct 1997) |
| flow cytometry | <technique> Flow cytometry is an emerging technique which holds great promise for the separation, classification and quantitation of blood cells and antibodies which affect blood cells. Complex computerised instruments are used to pass a monocellular stream of cells, platelets or other microscopic particulate elements through a beam of laser light. The cells are categorised first by size and then computer analysed to sort the mixture of cellular elements into cell type by size. Cells are labelled with fluorescent dye and then passed, in suspending medium, through a narrow dropping nozzle so that each cell is in a small droplet. A laser based detector system is used to excite fluorescence and droplets with positively fluorescent cells are given an electric charge. Charged and uncharged droplets are separated as they fall between charged plates and so collect in different tubes. The machine can be used either as an analytical tool, counting the number of labelled cells in a population or to separate the cells for subsequent growth of the selected population. Further sophistication can be built into the system by using a second laser system at right angles to the first to look at a second fluorescent label or to gauge cell size on the basis of light scatter. The great strength of the system is that it looks at large numbers of individual cells and makes possible the separation of populations with, for example: particular surface properties. Tabulation of counted data in conjunction with size analysis enables determination of relative percentages of each specific cellular subset for which monoclonal antibody conjugates are utilised, even when the size of the cell is identical to other subset species. Flow cytometry is a slightly imprecise but common term for the use of the Fluorescence-activated Cell Sorter (FACS). (01 Dec 1998) |
| flow cytophotometry | <technique> Flow cytometry is an emerging technique which holds great promise for the separation, classification and quantitation of blood cells and antibodies which affect blood cells. Complex computerised instruments are used to pass a monocellular stream of cells, platelets or other microscopic particulate elements through a beam of laser light. The cells are categorised first by size and then computer analysed to sort the mixture of cellular elements into cell type by size. Cells are labelled with fluorescent dye and then passed, in suspending medium, through a narrow dropping nozzle so that each cell is in a small droplet. A laser based detector system is used to excite fluorescence and droplets with positively fluorescent cells are given an electric charge. Charged and uncharged droplets are separated as they fall between charged plates and so collect in different tubes. The machine can be used either as an analytical tool, counting the number of labelled cells in a population or to separate the cells for subsequent growth of the selected population. Further sophistication can be built into the system by using a second laser system at right angles to the first to look at a second fluorescent label or to gauge cell size on the basis of light scatter. The great strength of the system is that it looks at large numbers of individual cells and makes possible the separation of populations with, for example: particular surface properties. Tabulation of counted data in conjunction with size analysis enables determination of relative percentages of each specific cellular subset for which monoclonal antibody conjugates are utilised, even when the size of the cell is identical to other subset species. Flow cytometry is a slightly imprecise but common term for the use of the Fluorescence-activated Cell Sorter (FACS). (01 Dec 1998) |
| flow injection analysis | The analysis of a chemical substance by inserting a sample into a carrier stream of reagent using a sample injection valve that propels the sample downstream where mixing occurs in a coiled tube, then passes into a flow-through detector and a recorder or other data handling device. (12 Dec 1998) |
| flow karyotyping | Use of flow cytometry toanalyse and/orseparate chromosomes on the basis of their DNA content. (09 Oct 1997) |
| flow rate | The amount of water that moves through an area (usually pipe) in a given period of time. (05 Dec 1998) |
| flow void | In magnetic resonance imaging, the absence of signal from blood whose activated protons leave a region before their magnetization is measured. See: signal void. (05 Mar 2000) |
| flow-over vaporiser | A device for vaporization of a liquid anaesthetic by causing gases to pass over the anaesthetic or over material saturated with the anaesthetic. (05 Mar 2000) |
| flow-volume curve | The graph produced by plotting the instantaneous flow of respiratory gas against the simultaneous lung volume, usually during maximal forced expiration. (05 Mar 2000) |
| flower | The sexual reproductive structure of the angiosperms, typically consisting of gynoecium, androecium and perianth and the main stem bearing these parts. (09 Oct 1997) |
| flower basket of Bochdalek | Part of the choroid plexus of the fourth ventricle protruding through Luschka's foramen and resting on the dorsal surface of the glossopharyngeal nerve. (05 Mar 2000) |
| Flower's bone | A sutural bone occasionally present at the pterion or junction of the parietal, frontal, greater wing of the sphenoid, and squamous portion of the temporal bone's. Synonym: Flower's bone. (05 Mar 2000) |
| Flower's dental index | Relation of the dental length (distance from the mesial surface of the first premolar to the distal surface of the third molar) to the basinasal (basion to nasion) length: (dental length ×100)/basinasal length, a system of numbers for indicating comparative size of the teeth. Synonym: Flower's dental index. (05 Mar 2000) |
| flower-de-luce | <botany> A genus of perennial herbs (Iris) with swordlike leaves and large three-petaled flowers often of very gay colours, but probably white in the plant first chosen for the royal French emblem. There are nearly one hundred species, natives of the north temperate zone. Some of the best known are Iris Germanica, I. Florentina, I. Persica, I. Sambucina, and the American I. Versicolour, I. Prismatica, etc. Origin: Corrupted fr. Fleur-de-lis. Source: Websters Dictionary (01 Mar 1998) |
| average flow rate | <physiology> The flow rate determined by dividing the total volume passed in a time period divided by the time period, usually quoted in mls per minute. (05 Mar 2000) |
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| Bingham flow | The flow characteristics exhibited by a Bingham plastic. (05 Mar 2000) |
| blood flow velocity | A value equal to the total volume flow divided by the cross-sectional area of the vascular bed. (12 Dec 1998) |
| gene flow | The movement of genes from one population to another viainterbreeding. (09 Oct 1997) |
| maximal expiratory flow rate | <chest medicine, physiology> Measurement of rate of airflow during the first liter expired after the first 200 ml have been exhausted during a forced vital capacity determination. Common abbreviations are MEFR, FEF 202-1200, and fef 0.2-1.2. Acronym: MEFR (21 Jun 2000) |
| maximal expiratory flow-volume curve | <chest medicine> Curves depicting maximal expiratory flow in liters/second at each point of lung inflation (expressed in liters or percentage of forced vital capacity) during a forced vital capacity determination. Common abbreviation is mefv. (12 Dec 1998) |
| maximal midexpiratory flow rate | Measurement of rate of airflow over the middle half of a forced vital capacity determination (from the 25 percent level to the 75 percent level). Common abbreviations are mmfr and fef 25%-75%. (12 Dec 1998) |
| renal blood flow, effective | The amount of blood flowing to the parts of the kidney that are involved with the production of constituents of urine. It is that portion of the total renal blood flow that perfuses functional renal tissue (e.g., the glomeruli). It should be differentiated from renal plasma flow, effective which is based on the amount of plasma rather than on total renal blood. (12 Dec 1998) |
| renal plasma flow | <physiology> The amount of plasma that perfuses the kidneys per unit time, approximately 10% greater than effective renal plasma flow. It should be differentiated from the renal blood flow which refers to the total volume of blood flowing through the renal vasculature, while the renal plasma flow refers to the rate of plasma flow. (12 Dec 1998) |
| peak expiratory flow | The maximum flow at the outset of forced expiration, which is reduced in proportion to the severity of airway obstruction, as in asthma. (05 Mar 2000) |
| peak expiratory flow rate | Measurement of the maximum rate of airflow attained during a forced vital capacity determination. Common abbreviations are pefr and pfr. (12 Dec 1998) |
| peak flow | <chest medicine, physiology> The maximum flow rate of air breathed out during forced expiration. (15 Nov 1997) |
| peak flow rate | Maximum urinary flow rate during voiding as measured by a uroflowmeter. (05 Mar 2000) |
| voiding flow rate | Urinary flow as a function of time during micturition, as graphically recorded by a flow meter. (05 Mar 2000) |
| cytometry, flow | Analysis of biological material by detection of the light-absorbing or fluorescing properties of cells or subcellular fractions such as chromosomes passing in a narrow stream through a laser beam. Flow cytometry is used with automated sorting devices to sort successive droplets of the stream into different fractions depending on the fluorescence emitted by each droplet. (12 Dec 1998) |