| 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) |
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| 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) |
| free electron |
An electron not bound to an atom or molecule. In this sense a (negative) beta particle is a free electron.
출처: amsglossary.allenpress.com/glossary/browse
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| free radical |
A chemical species that possesses an unpaired electron. These compounds, such as chlorine monoxide (ClO), hydroxyl radical (OH), and nitric oxide (NO), are characterized by a high chemical reactivity. Free radicals are often generated in the atmosphere from the photodissociation of more stable species. Their subsequent chemistry is central to such environmental issues as stratospheric ozone depletion and tropospheric oxidant production.
출처: amsglossary.allenpress.com/glossary/browse
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| freeze |
To attempt to retain possession of the ball or puck for an extended period of time without making an effort to score.
출처: library.thinkquest.org/12590/dictionary.htm
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| freezing |
the point at which cold turns liquid into solid.
출처: library.thinkquest.org/J001539/glossary.html
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| free radical |
Atom which carries an unpaired electron; free radicals can potentially injure cells and may be responsible for numerous age-related diseases.
출처: www.peteducation.com/dict_alpha_listing.cfm
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| free | a morpheme that can occur alone |
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| free | microscopic sensory nerve endings in the skin that are not connected to any specific sensory receptor |
| free | not held in check or subject to control |
| free | without payment |
| free | the formal act of liberating someone |
| free | people who are free |
| free | a phagocyte that circulates in the blood |
| free | a port open on equal terms to all commercial vessels |
| free | an area adjoining a port where goods that are intended for reshipment can be received and stored without payment of duties |
| free | an atom or group of atoms with at least one unpaired electron |
| free | the removal of constraints |
| free | a former political party in the United States |