| QF | quality factor; query fever; quick freeze; relative biological effectiveness |
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| OCP | octacalcium phosphate; ocular cicatricial pemphigoid; oral case presentation; oral contraceptive pil... |
| OET | oral endotracheal tube; oral esophageal tube |
| OHI | Occupational Health Institute; operative hypertension indicator; oral hygiene index; Oral Hygiene In... |
| OC | 1) Osteo-Calcin 2) Oral Contraceptive |
| 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) |
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| 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) |
| administration, oral | The giving of drugs, chemicals, or other substances by mouth. (12 Dec 1998) |
| cancer, oral | Cancer of the mouth area. A sore in the mouth that does not heal can be a warning sign of oral cancer. A biopsy is the only to know whether as abnormal area in the oral cavity is cancer. Oral cancer is caused by tobacco (smoking and chewing) and alcohol use. Surgery to remove the tumour in the mouth is the usual treatment for patients with oral cancer. (12 Dec 1998) |
| candidiasis, oral | Infection of the mucous membranes of the mouth by a fungus of the genus candida. (12 Dec 1998) |
| canine oral papilloma | Warts affecting mucous membranes of young dogs; caused by a papillomavirus. (05 Mar 2000) |
| magnesia and alumina oral suspension | A mixture of magnesium hydroxide and variable amounts of aluminum oxide; used as an antacid. (05 Mar 2000) |
| pathology, oral | A dental specialty concerned with pathology of the oral cavity. (12 Dec 1998) |
| pharyngo-oral | Relating to the pharynx and the mouth; oropharyngeal. Origin: pharyngo-+ L. Os (or-), mouth (05 Mar 2000) |
| combination oral contraceptive | A mixture of a steroid having progestational activity and an oestrogen. (05 Mar 2000) |
| contraceptives, oral | Compounds, usually hormonal, taken orally in order to block ovulation and prevent the occurrence of pregnancy. The hormones are generally oestrogen or progesterone or both. (12 Dec 1998) |
| contraceptives, oral, combined | Fixed drug combinations administered orally for contraceptive purposes. (12 Dec 1998) |
| contraceptives, oral, hormonal | Oral contraceptives which owe their effectiveness to hormonal preparations. (12 Dec 1998) |