| controlled thermonuclear fusion | <radiobiology> The process in which light nuclei, heated to a high temperature in a confined region, undergo fusion reactions under controlled conditions, with associated release of energy which may be harnessed for useful purposes. (09 Oct 1997) |
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| controlled thermonuclear research | General label for research on controlled thermonuclear fusion reactions. (09 Oct 1997) |
| controlled ventilation | Intermittent application of mechanically or manually generated positive pressure to gas(es) in or about the airway as a means of forcing gases into the lungs in the absence of spontaneous ventilatory efforts. Synonym: controlled respiration. (05 Mar 2000) |
| pressure-controlled respirator | A respirator that provides a predetermined pressure to gases during inhalation, the volume of gas moved being variable, depending upon resistance. (05 Mar 2000) |
| noncondensing, controlled extraction turbine | A turbine that bleeds part of the main steam flow at one (single extraction) or two (double extraction) points. (05 Dec 1998) |
| environment, controlled | A state in which the environs of hospitals, laboratories, domestic and animal housing, work places, spacecraft, and other surroundings are under technological control with regard to air conditioning, heating, lighting, humidity, ventilation, and other ambient features. The concept includes control of atmospheric composition. (12 Dec 1998) |
| Bernoulli trial | A single random event for which there are two and only two possible outcomes that are mutually exclusive and have a priori fixed (and complementary) probabilities of resulting. The trial is the realization of this process. Conventionally one outcome is termed a success and is assigned the score 1, the other is a failure and has the score zero. Thus the outcome might be 0 (no heads, one tail) or 1 (1 head, no tails). (05 Mar 2000) |
| randomised trial | <statistics> A clinical trial in which patients have been randomly assigned to receive either the study drug or alternative treatment, in which neither the patient nor the physician conducting the study know which treatment is being given the patient, and in which the alternative to the study drug is a placebo, the study is conducted at several centres. (09 Oct 1997) |
| phase I clinical trial | <pharmacology> The earliest stage clinical trial for studying an experimental drug in humans. Phase I trials are generally comparatively small and are used to determine toxicity and maximum dose. They provide an initial evaluation of a drug's safety and pharmacokinetics-how the drug is absorbed, what tissues it reaches and how long it takes to leave the body. Such studies also usually test various doses of the drug (dose-ranging) to obtain an indication of the appropriate dose to use in later studies. The patients in these trials usually have advanced disease and have already received best available chemotherapy, therefore, seeing a repose is significant partially because this means there is a lack of cross-resistance between two anti-cancer drugs. (31 Dec 1997) |
| phase II clinical trial | <pharmacology> Usually focus on the activity of the new product as a single agent in a noncomparative, open study. (31 Dec 1997) |
| phase III clinical trial | <pharmacology> An advanced stage clinical trial that should conclusively show how well a drug works as compared to other treatments. Phase III trials are large, frequently multi-institution tests. They generally compare the relative value of the new drug compared with the current standard treatment and measure whether a new drug extends survival or otherwise improves the health of patients on treatment (clinical improvement) rather than just provide surrogate marker data. These studies generally last longer and are larger than phase II trials. (31 Dec 1997) |
| clinical trial | <pharmacology> Research study conducted with patients, usually to evaluate a new treatment or drug. Each trial is designed to answer scientific questions and to find better ways to treat individuals with a specific disease. (12 May 1997) |
| clinical trial, phase I | A pre-planned, usually controlled, clinical study of the safety and efficacy of diagnostic, therapeutic, or prophylactic drugs, devices, or techniques based on a small number of healthy persons and conducted over the period of about a year in either the united states or a foreign country. (12 Dec 1998) |
| clinical trial, phase II | A pre-planned, usually controlled, clinical study of the safety and efficacy of diagnostic, therapeutic, or prophylactic drugs, devices, or techniques based on several hundred volunteers, including a limited number of patients, and conducted over a period of about two years in either the united states or a foreign country. (12 Dec 1998) |
| clinical trial, phase III | A pre-planned, usually controlled, clinical study of the safety and efficacy of diagnostic, therapeutic, or prophylactic drugs, devices, or techniques after phase II trials. A large enough group of patients is studied and closely monitored by physicians for adverse response to long-term exposure, over a period of about three years in either the united states or a foreign country. (12 Dec 1998) |