| 释义 |
tracer
trac·er T0299000 (trā′sər)n.1. a. One who is employed to locate missing goods or persons.b. An investigation or inquiry organized to trace missing goods or persons.2. Any of several instruments used in making tracings or in imprinting designs by tracing.3. A tracer bullet.4. An identifiable substance, such as a dye or a radioactive isotope, that is introduced into a biological or mechanical system and can be followed through the course of a process, providing information on the pattern of events in the process or on the redistribution of the parts or elements involved. Also called label.tracer (ˈtreɪsə) n1. a person or thing that traces2. (Firearms, Gunnery, Ordnance & Artillery) a. a projectile that can be observed when in flight by the burning of chemical substances in its baseb. ammunition consisting of such projectilesc. (as modifier): tracer fire. 3. (Medicine) med any radioactive isotope introduced into the body to study metabolic processes, absorption, etc, by following its progress through the body with a gamma camera or other detector4. an investigation to trace missing cargo, mail, etctrac•er (ˈtreɪ sər)
n. 1. a person or thing that traces. 2. a person whose business or work is the tracing of missing property, parcels, persons, etc. 3. an inquiry sent from point to point to trace a missing shipment, parcel, or the like. 4. a projectile, as a bullet, containing a chemical substance that leaves a trail of fire or smoke. 5. a substance, esp. a radioactive one, traced through a biological, chemical, or physical system in order to study the system. [1535–45] trac·er (trā′sər) An identifiable substance, such as a dye or radioactive isotope, that can be followed through the course of a mechanical, chemical, or biological process. Tracers are used to provide information about details of the process or about the distribution of the substances involved in it.Thesaurus| Noun | 1. |  tracer - an investigator who is employed to find missing persons or missing goodsdetective, police detective, tec, investigator - a police officer who investigates crimes | | 2. |  tracer - an instrument used to make tracingsinstrument - a device that requires skill for proper use | | 3. | tracer - (radiology) any radioactive isotope introduced into the body to study metabolism or other biological processesradiology - the branch of medical science dealing with the medical use of X-rays or other penetrating radiationradioisotope - a radioactive isotope of an element; produced either naturally or artificially | | 4. |  tracer - ammunition whose flight can be observed by a trail of smoketracer bulletammo, ammunition - projectiles to be fired from a gun |
Translationstracer
tracer, an identifiable substance used to follow the course of a physical, chemical, or biological process. In chemistry the ideal tracer has the same chemical properties as the molecule it replaces and undergoes the same reactions but can at all times be detectible and quantitatively assessed. In biochemistry tracers have been in use since the beginning of the 20th cent. Using synthetic methods, Franz Knoop in 1904 made various derivatives of fatty acids, the degradation of which he studied by feeding the derivatives to dogs and by monitoring the appearance of unusual products in the dogs' urine. From these studies were obtained the first descriptions of the metabolic pathway for fatty acid catabolism. About these sorts of experiments, however, the argument could always be made that the derivatives were "unphysiological," that is, did not occur naturally and might be handled by the enzymes of the body differently than "physiological" compounds. This difficulty was overcome in 1935 when Rudolf Schoenheimer and David Rittenberg described the use of the isotope deuterium (identical to the hydrogen atom except that it contains an extra neutron) in following biochemical reactions. They argued persuasively that deuterium-labeled compounds (those having a deuterium atom substituted for a hydrogen) were essentially indistinguishable from nonlabeled compounds as far as metabolic processes were concerned but that the amount of deuterium in any given sample could be quantitatively determined by the properties of the water produced upon combustion of the sample. Although this was the first declaration of the general usefulness of the approach, George Hevesy in 1923 was the first investigator to use an isotope in metabolic studies; he explored lead transport in the bean plant using radioactive thorium. Radioactive isotopes are more easily detected than nonradioactive ones, such as deuterium; therefore, when the radioactive isotopes of various atoms commonly occurring in organic molecules became widely available after World War II, metabolic studies proliferated. Isotopes in common use today include carbon-14, iodine-131, nitrogen-15, oxygen-17, phosphorus-32, sulfur-35, tritium (hydrogen-3), iron-59, and sodium-24.tracer[′trā·sər] (chemistry) A foreign substance, usually radioactive, that is mixed with or attached to a given substance so the distribution or location of the latter can later be determined; used to trace chemical behavior of a natural element in an organism. Also known as tracer element. (engineering) A thread of contrasting color woven into the insulation of a wire for identification purposes. tracer Med any radioactive isotope introduced into the body to study metabolic processes, absorption, etc., by following its progress through the body with a gamma camera or other detector tracer
tracer [trās´er] 1. a means or agent by which certain substances or structures can be identified or followed, as a radioactive tracer.2. a mechanical device by which the outline of an object or the direction and extent of movement of a part may be graphically recorded; see also tracing.3. a dissecting instrument for isolating vessels and nerves.radioactive tracer a radioactive isotope replacing a stable chemical element in a compound (said to be radiolabeled) and so able to be followed or tracked through one or more reactions or systems by means of a radiation detector; used especially for such a compound that is introduced into the body for study of the compound's metabolism, distribution, and passage through the body.trac·er (trās'ĕr), 1. An element or compound containing atoms that can be distinguished from their normal counterparts by physical means (for example, radioactivity assay or mass spectrography) and can thus be used to follow (trace) the metabolism of the normal substances.
See also: tracing (2). 2. A colored or radioactive substance that can be injected in the region of a tumor (for example, melanoma, breast) to map the flow of lymph from the tumor to its nearest nodal basin; used in sentinel node detection.
See also: tracing (2). 3. A colored substance (for example, a dye) used as a tracer to follow the flow of water.
See also: tracing (2). 4. An instrument used in dissecting out nerves and blood vessels.
See also: tracing (2). 5. A mechanical device with a marking point attached to one jaw and a graph plate or tracing plate attached to the other jaw; used to record the direction and extent of movements of the mandible.
See also: tracing (2). [M.E. track, fr. O. Fr. tracier, to make one's way, fr. L. traho, pp. tractum, to draw, + -er, agent suffix] tracer (trā′sər)n. An identifiable substance, such as a dye or a radioactive isotope, that is introduced into a biological or mechanical system and can be followed through the course of a process, providing information on the pattern of events in the process or on the redistribution of the parts or elements involved. Also called label.tracer Imaging A substance, such as a radioisotope, used in imaging procedurestrac·er (trā'sĕr) 1. An element or compound containing atoms that can be distinguished from their normal counterparts by physical means (e.g., radioactivity assay or mass spectrography) and can thus be used to follow (trace) the metabolism of the normal substances. 2. A colored substance (e.g., a dye) used as a tracer to follow the flow of water. 3. An instrument used in dissecting out nerves and blood vessels. 4. A mechanical device with a marking point attached to one jaw and a graph plate or tracing plate attached to the other jaw; used to record the direction and extent of movements of the mandible.
See also: tracing (2) tracer 1. A biochemical that has been tagged with a radioactive atom so that its destination can be determined. 2. A length of nucleic acid tagged with a radioactive atom that can be used to find and identify samples of its complementary strand. tracer any rare ISOTOPE, for example radioactive forms such as 14C, which is administered in some way to organisms so that its fate may be subsequently followed within the organism or in the products of its METABOLISM.trac·er (trā'sĕr) 1. A mechanical device with a marking point attached to one jaw and a graph plate or tracing plate attached to the other jaw; used to record direction and extent of mandibular movements. 2. An element or compound containing atoms that can be distinguished from their normal counterparts by physical means (e.g., radioactivity assay or mass spectrography) and can thus be used to follow (trace) metabolism of normal substances. 3. Colored or radioactive substance that can be injected in region of a tumor (e.g., melanoma, breast) to map lymph flow from tumor to its nearest nodal basin; used in sentinel node detection. FinancialSeeTracersTRACER
| Acronym | Definition |
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| TRACER➣Transition Radiation Array for Cosmic Energetic Radiation (balloon-borne instrument) | | TRACER➣Tactical Reconnaissance Armoured Combat Equipment Requirement | | TRACER➣Teacher Relief and Contract Employment Register (Australia) | | TRACER➣Transportation Cost Estimator | | TRACER➣Transportable Remote Analyzer for Characterization and Environmental Remediation | | TRACER➣Tropospheric Radiometer for Atmospheric Chemistry and Environmental Research |
See TRACtracer
Related to tracer: traces, trackerSynonyms for tracernoun an investigator who is employed to find missing persons or missing goodsRelated Words- detective
- police detective
- tec
- investigator
noun an instrument used to make tracingsRelated Wordsnoun (radiology) any radioactive isotope introduced into the body to study metabolism or other biological processesRelated Wordsnoun ammunition whose flight can be observed by a trail of smokeSynonymsRelated Words |