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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.
a molecule containing a radioactive atom, which can be followed through a physiological system with radiation detectors.
n a molecule to which a radioactive atom has been attached so that it can be followed through a physiologic system with radiation detectors.
characterized by radioactivity.
spontaneous decomposition of the nuclei of the atoms of radioactive substances. Measured as the proportion of the atoms in a radionuclide that decompose per unit of time, usually stated as the half-life of that particular isotope.
dissemination of radioactive substances through the atmosphere and deposition on the environment generally; causes radiation injury.
radionuclide. A radioactive nuclide, e.g. radioactive iodine or strontium.
see radioactive tracer.
a means by which something may be followed, as (1) a mechanical device by which the outline or movements of an object can be graphically recorded, or (2) a material by which the progress of a compound through the body may be observed.
a radioactive isotope replacing a stable chemical element in a compound introduced into the body, enabling its metabolism, distribution and elimination to be followed in the living animal.