specific activity


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spe·cif·ic ac·tiv·i·ty

1. radioactivity per unit mass of the stated element or compound;
2. for an enzyme, the amount of substrate consumed (or product formed) in a given time under given conditions per milligram of protein;
3. activity per unit mass of the stated radionuclide.

specific activity

1 the radioactivity of a radioisotope per unit mass of the element or compound, expressed in microcuries per millimole or disintegrations per second per milligram.
2 the relative radioactivity per unit mass, expressed as counts per minute per milligram. For example, the specific activity of potassium in the human body is the same as that in the environment or diet. Because potassium is associated chiefly with muscle tissue, a whole-body count of 40K, after administration of radioactive potassium, can be used to distinguish lean body mass from total body mass.

spe·cif·ic ac·tiv·i·ty

(spĕ-sif'ik ak-tiv'i-tē)
1. Radioactivity per unit mass of the stated element or compound.
2. For an enzyme, the amount of substrate consumed (or product formed) in a given time under given conditions per milligram of protein.
3. Activity per unit mass of the stated radionuclide.
References in periodicals archive ?
The absolute error of specific activity shall be calculated according to a formula (Dimaviciene, Butkus 2007):
where: A--radionuclide specific activity in a sample, determined according to formula (2), Bq/kg; p--measurement relative error, determined by a spectrometer, %; [DELTA]t--measurement time error, s; [DELTA]m--sample weight determination error, kg.
10 presents a variation in the specific activity of [sup.
It is seen from the Figure that the highest specific activity was established in Bores 5 and 6.
226]Ra specific activity was determined in Bores 3 and 4.
227]Ac specific activity in the silt of Lake Didziulis is provided in Fig.
The study shows that Alferon N(R), inhibits SARS-CoV at a high specific activity in Vero 76 cells (African green monkey) in culture.
The concentration methods increase the specific activity of the technetium produced in generators, making the radioisotope strong enough to be useful for brain, bone and heart scans and numerous other medical tests.
NNL has pioneered several new technologies that allow for rapid screening of compounds for specific activity at glutamate transporters.
Currently the company has compassionate use trials underway for its compound PN 27, 1, which has been found to have safe and effective activity against prostate and breast cancers and non-Hodgkin's lymphomas, as well as initial clinical trials at the Bastyr University in Seattle for its PN 355 compound, which has been found to have specific activity against HIV.
TravelGAM is an orally administered, hyperimmune, milk-derived antibody concentrate which has specific activity against enterotoxigenic Escherichia coli ("ETEC"), the most common cause of travelers' diarrhea worldwide.
Log Auditor scans DB2 logs for specific activity and then summarizes the selected activity; Deadlock

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