| EHF | epidemic hemorrhagic fever; exophthalmos-hyperthyroid factor; extreme high frequency |
|---|---|
| hf | half; high frequency |
| HFC | hard filled capsule; high-frequency current; histamine-forming capacity |
| HFJV | high-frequency jet ventilation |
| HFO-A | high-frequency oscillatory [ventilation]-active [expiratory phase] |
| frequency encoding | In magnetic resonance imaging, a method of varying the magnetic field strength with location to encode the location of each voxel uniquely in one direction. (05 Mar 2000) |
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| frequency of micturition | Micturition at short intervals; it may result from increased urine formation, decreased bladder capacity, or lower urinary tract irritation. (05 Mar 2000) |
| frequency of occurrence | The number of times a given event occurs at specified sample points during a defined period. (07 Apr 1998) |
| frequency spectrum | The range of frequencies in a signal, used to describe the resolving power of an imaging system in radiology. (05 Mar 2000) |
| frequency, urinary | Urinating too often, at too frequent intervals, not due to an unusually large volume of urine, but rather to a decrease in the capacity of the bladder to hold urine. (12 Dec 1998) |
| fundamental frequency | The principal component of a sound wave, which has the greatest wavelength, tone produced by the vibration of the vocal folds before the air reaches any cavities. (05 Mar 2000) |
| low frequency transduction | Specialised transduction in which only a small portion of the prophage particles, because of their defectiveness, are able to develop sufficiently to serve as effective transducing agents. (05 Mar 2000) |
| cardiac output, high | A state of elevated cardiac output. Conditions that lower peripheral vascular resistance, such as anaemia, arteriovenous fistulas, thyrotoxicosis, and pregnancy, are among the most important factors augmenting the venous return and therefore elevating cardiac output. Increased cardiac output also occurs in muscular exercise, fever, and severe anoxia. (12 Dec 1998) |
| radiotherapy, high-energy | Radiotherapy using high-energy (megavolt or higher) ionizing radiation. Types of radiation include gamma rays, produced by a radioisotope within a teletherapy unit; X-rays, electrons, protons, alpha particles (helium ions) and heavy charged ions, produced by particle acceleration; and neutrons and pi-mesons (pions), produced as secondary particles following bombardment of a target with a primary particle. (12 Dec 1998) |
| mean higher high water | <marine biology> The average height of the higher high water over a 19-year period. For shorter periods of observation, corrections are applied to eliminate known variations and reduce the result to the equivalent of a mean 19-year value. (09 Oct 1997) |
| mean high water | <marine biology> The average height of the high water over a 19-year period. For shorter periods of observation, corrections are applied to eliminate known variations and reduce the result to the equivalent of a mean 19-year value. All high-waters heights are included in the average where the type of tide is either semidiurnal or mixed. Only the higher high-water heights are included in the average where the type of tide is diurnal. So determined, mean high water in the latter case is the same as mean higher high water. (09 Oct 1997) |
| chromatography, high pressure liquid | Liquid chromatographic techniques which feature high inlet pressures, high sensitivity, and high speed. (12 Dec 1998) |
| pregnancy, high-risk | Pregnancy in which the mother and/or foetus are at greater than normal risk of morbidity or mortality. Causes include lack of adequate prenatal care, previous obstetrical history, pre-existing maternal disease or pregnancy-induced disease, and multiple gestation, as well as advanced maternal age. (12 Dec 1998) |
| high | 1. Elevated above any starting point of measurement, as a line, or surface; having altitude; lifted up; raised or extended in the direction of the zenith; lofty; tall; as, a high mountain, tower, tree; the sun is high. 2. Regarded as raised up or elevated; distinguished; remarkable; conspicuous; superior; used indefinitely or relatively, and often in figurative senses, which are understood from the connection. Elevated in character or quality, whether moral or intellectual; preeminent; honorable; as, high aims, or motives. "The highest faculty of the soul." Exalted in social standing or general estimation, or in rank, reputation, office, and the like; dignified; as, she was welcomed in the highest circles. "He was a wight of high renown." (Shak) Of noble birth; illustrious; as, of high family. Of great strength, force, importance, and the like; strong; mighty; powerful; violent; sometimes, triumphant; victorious; majestic, etc.; as, a high wind; high passions. "With rather a high manner." "Strong is thy hand, and high is thy right hand." (Ps. Lxxxix. 13) "Can heavenly minds such high resentment show?" (Dryden) Very abstract; difficult to comprehend or surmount; grand; noble. "Both meet to hear and answer such high things." (Shak) "Plain living and high thinking are no more." (Wordsworth) Costly; dear in price; extravagant; as, to hold goods at a high price. "If they must be good at so high a rate, they know they may be safe at a cheaper." (South) Arrogant; lofty; boastful; proud; ostentatious; used in a bad sense." "An high look and a proud heart . . . Is sin." (Prov. Xxi. 4) "His forces, after all the high discourses, amounted really but to eighteen hundred foot." (Clarendon) 3. Possessing a characteristic quality in a supreme or superior degree; as, high (i. E, intense) heat; high (i. E, full or quite) noon; high (i. E, rich or spicy) seasoning; high (i. E, complete) pleasure; high (i. E, deep or vivid) colour; high (i. E, extensive, thorough) scholarship, etc. "High time it is this war now ended were." (Spenser) "High sauces and spices are fetched from the Indies." (Baker) 4. Strong-scented; slightly tainted; as, epicures do not cook game before it is high. 5. Acute or sharp; opposed to grave or low; as, a high note. 6. Made with a high position of some part of the tongue in relation to the palate, as e (eve), oo (food). High admiral, the chief admiral. High altar, the principal altar in a church. High and dry, out of water; out of reach of the current or tide; said of a vessel, aground or beached. High and mighty arrogant; overbearing. High art, art which deals with lofty and dignified subjects and is characterised by an elevated style avoiding all meretricious display. High bailiff, the chief bailiff. High Church, and Low Church, two ecclesiastical parties in the Church of England and the Protestant Episcopal Church. The high-churchmen emphasize the doctrine of the apostolic succession, and hold, in general, to a sacramental presence in the Eucharist, to baptismal regeneration, and to the sole validity of Episcopal ordination. They attach much importance to ceremonies and symbols in worship. Low-churchmen lay less stress on these points, and, in many instances, reject altogether the peculiar tenets of the high-church school. See Broad Church. High constable, the open sea; the part of the ocean not in the territorial waters of any particular sovereignty, usually distant three miles or more from the coast line. High steam, steam having a high pressure. High steward, the chief steward. High tea, tea with meats and extra relishes. High tide, the greatest flow of the tide; high water. High time. Quite time; full time for the occasion. A time of great excitement or enjoyment; a carousal. High treason, treason against the sovereign or the state, the highest civil offense. See Treason. It is now sufficient to speak of high treason as treason simply, seeing that petty treason, as a distinct offense, has been abolished. High water, the utmost flow or greatest elevation of the tide; also, the time of such elevation. High-water mark. That line of the seashore to which the waters ordinarily reach at high water. A mark showing the highest level reached by water in a river or other body of fresh water, as in time of freshet. <botany> High-water shrub, a composite shrub (Iva frutescens), growing in salt marshes along the Atlantic coast of the United States. High wine, distilled spirits containing a high percentage of alcohol; usually in the plural. To be on a high horse, to be on one's dignity; to bear one's self loftily. With a high hand. With power; in force; triumphantly. "The children of Israel went out with a high hand." In an overbearing manner, arbitrarily. "They governed the city with a high hand." . Synonym: Tall, lofty, elevated, noble, exalted, supercilious, proud, violent, full, dear. See Tall. Origin: OE. High, hegh, hey, heh, AS. Heah, hh; akin to OS. Hh, OFries. Hag, hach, D. Hoog, OHG. Hh, G. Hoch, Icel. Hr, Sw. Hog, Dan. Hoi, Goth. Hauhs, and to Icel. Haugr mound, G. Hugel hill, Lith. Kaukaras. Source: Websters Dictionary (01 Mar 1998) |
| high altitude cerebral oedema | <physiology> A serious condition that results from the sudden increase in pressure within the brain due to swelling. This is thought to occur secondary to exposure to high altitudes, generally in excess of 12,000 feet. (12 Jan 1998) |