| freemartin | <veterinary, zoology> A condition occurring in dizygotic twins of different sexes in cattle, where an imperfect masculinised sterile female twin calf is born with a male. This results from twin foetuses of opposite sexes in which the chorionic blood vessels become fused at an early stage of embryonic development, with the result that the hormones of the male twin are conveyed in the circulation to the female twin and influence its sexual development. Both calves are blood cell chimeras with immune tolerance, due to interchange of cells in utero. Freemartins are a type of hermaphrodite with underdeveloped uterus, enlarged penis-like clitoris, and, sometimes, structures resembling the ductus deferens and seminal vesicles. (21 Jun 2000) |
|---|---|
| freemartinism | <veterinary, zoology> A condition occurring in dizygotic twins of different sexes in cattle, where an imperfect masculinised sterile female twin calf is born with a male. This results from twin foetuses of opposite sexes in which the chorionic blood vessels become fused at an early stage of embryonic development, with the result that the hormones of the male twin are conveyed in the circulation to the female twin and influence its sexual development. Both calves are blood cell chimeras with immune tolerance, due to interchange of cells in utero. Freemartins are a type of hermaphrodite with underdeveloped uterus, enlarged penis-like clitoris, and, sometimes, structures resembling the ductus deferens and seminal vesicles. (21 Jun 2000) |
| freeway space | The space between the occluding surfaces of the maxillary and mandibular teeth when the mandible is in physiologic resting position. Synonym: interocclusal clearance, interocclusal distance, interocclusal gap, interocclusal rest space. (05 Mar 2000) |
| freeze | 1. To become congealed by cold; to be changed from a liquid to a solid state by the abstraction of heat; to be hardened into ice or a like solid body. Water freezes at 32 deg above zero by Fahrenheit's thermometer; mercury freezes at 40 deg below zero. 2. To become chilled with cold, or as with cold; to suffer loss of animation or life by lack of heat; as, the blood freezes in the veins. To freeze up ( Origin: OE. Fresen, freosen, AS. Freosan; akin to D. Vriezen, OHG. Iosan, G. Frieren, Icel. Frjsa, Sw. Frysa, Dan. Fryse, Goth. Frius cold, frost, and prob. To L. Prurire to itch, E. Prurient, cf. L. Prna a burning coal, pruina hoarfrost, Skr. Prushva ice, prush to spirt. 18. Cf. Frost. Source: Websters Dictionary (01 Mar 1998) |
| freeze cleavage | Method of specimen preparation for the electron microscope in which rapidly frozen tissue is cracked so as to produce a fracture plane through the specimen. The surface of the fracture plane is then shadowed by heavy metal vapour, strengthened by a carbon film and the underlying specimen is digested away, leaving a replica that can be picked up on a grid and examined in the transmission electron microscope. The great advantage of the method is that the fracture plane tends to pass along the centre of lipid bilayers and it is therefore possible to get en face views of membranes that reveal the pattern of Integral membrane proteins. The E face is the outer lamella of the plasma membrane viewed as if from within the cell, the P face the inner lamella viewed from outside the cell. Fracture planes also often pass along lines of weakness such as the interface between cytoplasm and membrane, so that outer and inner membrane surfaces can be viewed. Further information about the structure can be revealed by freeze etching. Extremely rapid freezing followed by deep etching has allowed the structure of the cytoplasm to be studied without the artefacts that might be introduced by fixation. (18 Nov 1997) |
| freeze etch | <microscopy, technique> A method of preparing a cell for study by freezing it, cracking it open to reveal the organelles, freeze drying it, then examining it under the electron microscope. (09 Oct 1997) |
| freeze etching | If a freeze fractured specimen is left for any length of time before shadowing, then water will sublime off from the specimen etching (lowering) those surfaces that are not protected by a lipid bilayer. Some etching will take place following any freeze cleavage process, in deep etching the ice surface is substantially lowered to reveal considerable detail of, for example: cytoplasmic filament systems. (18 Nov 1997) |
| freeze fracture | Method of specimen preparation for the electron microscope in which rapidly frozen tissue is cracked so as to produce a fracture plane through the specimen. The surface of the fracture plane is then shadowed by heavy metal vapour, strengthened by a carbon film and the underlying specimen is digested away, leaving a replica that can be picked up on a grid and examined in the transmission electron microscope. The great advantage of the method is that the fracture plane tends to pass along the centre of lipid bilayers and it is therefore possible to get en face views of membranes that reveal the pattern of Integral membrane proteins. The E face is the outer lamella of the plasma membrane viewed as if from within the cell, the P face the inner lamella viewed from outside the cell. Fracture planes also often pass along lines of weakness such as the interface between cytoplasm and membrane, so that outer and inner membrane surfaces can be viewed. Further information about the structure can be revealed by freeze etching. Extremely rapid freezing followed by deep etching has allowed the structure of the cytoplasm to be studied without the artefacts that might be introduced by fixation. (18 Nov 1997) |
| freeze fracturing | Preparation for electron microscopy of minute replicas of exposed surfaces of the cell which have been ruptured in the frozen state. The specimen is frozen, then cleaved under high vacuum at the same temperature. The exposed surface is shadowed with carbon and platinum and coated with carbon to obtain a carbon replica. (12 Dec 1998) |
| freeze substitution | A modification of the freeze-drying method in which the ice within the frozen tissue is replaced by alcohol or other solvent at a very low temperature. (12 Dec 1998) |
| freeze-drying | <technique> Method commonly adopted to produce a dry and stable form of biological material that has not been seriously denatured. By freezing the specimen, often with liquid nitrogen and then subliming water from the specimen under vacuum, proteins are left in reasonably native form and can usually be rehydrated to an active state. Since the freeze dried material will store without refrigeration for long periods, it is a convenient method for holding back up or reference material or for the distribution of antibiotics, vaccines etc. Synonym: lyophilization. (18 Sep 2002) |
| freezing | Tending to freeze; for freezing; hence, cold or distant in manner. Freezing machine. See Ice machine, under Ice. Freezing mixture, a mixture (of salt and snow or of chemical salts) for producing intense cold. Freezing point, that degree of a thermometer at which a fluid begins to freeze; applied particularly to water, whose freezing point is at 32 deg Fahr, and at 0 deg Centigrade. Source: Websters Dictionary (01 Mar 1998) |
| freezing point | <physics> The temperature at which a liquid solidifies. (05 Mar 2000) |
| Frei test | <investigation> A clinical test where dead disease-causing microbes are injected into the skin to see if this causes a skin reaction. It indicates whether the patient is infected with the the injected microbe and is not used commonly. (07 Apr 1998) |
| Frei, Wilhelm | <person> German dermatologist, 1885-1943. See: Frei test, Frei-Hoffmann reaction. (05 Mar 2000) |
Synonyms : D-Isoglucosamine, D Isoglucosamine
Synonyms : Apir Levulosa, Baxter Brand of Fructose, Bieffe Brand of Fructose, Braun Brand of Fructose, Ern Brand of Fructose, Fleboplast Levulosa, Fresenius Kabi Brand of Fructose, Grifols Brand of Fructose, Instituto Farmacologico Brand of Fructose, Levulosa, Levulosa Ife
Synonyms : Fructose Intolerances, Intolerance, Fructose, Intolerances, Fructose
Synonyms :
Synonyms : Deficiency, Hexosediphosphatase, Fructose 1, 6 Diphosphatase Deficiency, Fructosediphosphatase Deficiency, Deficiencies, Fructose-1, 6-Bisphosphatase, Deficiencies, Fructose-1, 6-Diphosphatase, Deficiencies, Fructose-Biphosphatase
| free association |
a thought process in which ideas (words or images) suggest other ideas in a sequence
출처: wordnet.princeton.edu/perl/webwn
|
|---|---|
| frostbite |
destruction of tissue by freezing and characterized by tingling, blistering and possibly gangrene
출처: wordnet.princeton.edu/perl/webwn
|
| frottage |
masturbation by rubbing against another person (as in a crowd)
출처: wordnet.princeton.edu/perl/webwn
|
| free radical |
an atom or group of atoms with at least one unpaired electron; in the body it is usually an oxygen molecule than has lost an electron and will stabilize itself by stealing an electron from a nearby molecule; "in the body free radicals are high-energy particles that ricochet wildly and damage cells"
출처: wordnet.princeton.edu/perl/webwn
|
| freeze-drying |
a method of drying food or blood plasma or pharmaceuticals or tissue without destroying their physical structure; material is frozen and then warmed in a vacuum so that the ice sublimes
출처: wordnet.princeton.edu/perl/webwn
|
| FR | Spanish explorer who discovered Yucatan (1475-1526) |
|---|---|
| FR | Spanish general whose armies took control of Spain in 1939 and who ruled as a dictator until his death (1892-1975) |
| FR | Spanish painter well known for his portraits and for his satires (1746-1828) |
| FR | prelate who was the confessor of Isabella I and who was later appointed Grand Inquisitor (1436-1517) |
| FR | Spanish painter well known for his portraits and for his satires (1746-1828) |
| FR | Spanish painter well known for his portraits and for his satires (1746-1828) |
| FR | Spanish explorer who conquered the Inca Empire in Peru and founded Lima (1475-1541) |
| FR | Mexican revolutionary leader (1877-1923) |
| FR | a radioactive element of the alkali-metal group discovered as a disintegration product of actinium |
| FR | United States physicist (born in Germany) who with Gustav Hertz performed an electron scattering experiment that proved the existence of the stationary energy states postulated by Niels Bohr (1882-1964) |
| FR | French composer and teacher who influenced a generation of composers (1822-1890) |
| FR | Spanish general whose armies took control of Spain in 1939 and who ruled as a dictator until his death (1892-1975) |