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Physics in Medicine and Biology Apr 1959
Topics: Activation Analysis; Gold Colloid; Gold Radioisotopes; Kinetics; Liver Function Tests; Mononuclear Phagocyte System
PubMed: 13674897
DOI: 10.1088/0031-9155/3/4/305 -
The Medical Journal of Australia Oct 1986
Topics: Activation Analysis; Body Composition; Humans; Neutron Activation Analysis
PubMed: 3762456
DOI: 10.5694/j.1326-5377.1986.tb113832.x -
Lancet (London, England) Dec 1964
Topics: Activation Analysis; Chemistry Techniques, Analytical; Clinical Laboratory Techniques; Humans; Laboratories; Neutrons
PubMed: 14215559
DOI: 10.1016/s0140-6736(64)91041-4 -
Analytical Biochemistry Sep 1964
Topics: Acids; Activation Analysis; Amino Acids; Autoradiography; Carbohydrates; Chromatography; Fatty Acids; Keto Acids; Research
PubMed: 14246119
DOI: 10.1016/0003-2697(64)90080-6 -
The International Journal of Applied... 1958
Topics: Humans; Isotopes; Neutron Activation Analysis
PubMed: 13524978
DOI: 10.1016/0020-708x(58)90003-6 -
Radioisotopes Mar 1980Some effects of self-shielding of neutron flux in neutron activation analysis have been investigated. Induced specific activities in dilute samples were compared with...
Some effects of self-shielding of neutron flux in neutron activation analysis have been investigated. Induced specific activities in dilute samples were compared with those in solid elements irradiated under the same conditions. Two factors affecting the neutron flux were investigated: thermal neutron self-shielding and epithermal neutron self-shielding. The former effect can be computed reasonably accurately, using a well-known approximation. Self-shielding of epithermal neutrons cannot be calculated rigorously, so an empirical approach was used. The self-shielding effects of neutron flux were evaluated for uranium and a maximum permissible weight has been calculated by assuming that the product of the maximum permissible weight and the atom density is a function of the ratio of the resonance integral of the absorbing element to that of uranium.
Topics: Activation Analysis; Neutron Activation Analysis; Neutrons; Uranium
PubMed: 7455174
DOI: 10.3769/radioisotopes.29.3_119 -
Medical Physics Feb 1996The delayed-gamma neutron activation facility at Brookhaven National Laboratory was originally calibrated using an anthropomorphic hollow phantom filled with solutions... (Comparative Study)
Comparative Study
The delayed-gamma neutron activation facility at Brookhaven National Laboratory was originally calibrated using an anthropomorphic hollow phantom filled with solutions containing predetermined amounts of Ca. However, 99% of the total Ca in the human body is not homogeneously distributed but contained within the skeleton. Recently, an artificial skeleton was designed, constructed, and placed in a bottle phantom to better represent the Ca distribution in the human body. Neutron activation measurements of an anthropomorphic and a bottle (with no skeleton) phantom demonstrate that the difference in size and shape between the two phantoms changes the total body calcium results by less than 1%. To test the artificial skeleton, two small polyethylene jerry-can phantoms were made, one with a femur from a cadaver and one with an artificial bone in exactly the same geometry. The femur was ashed following the neutron activation measurements for chemical analysis of Ca. Results indicate that the artificial bone closely simulates the real bone in neutron activation analysis and provides accurate calibration for Ca measurements. Therefore, the calibration of the delayed-gamma neutron activation system is now based on the new bottle phantom containing an artificial skeleton. This change has improved the accuracy of measurement for total body calcium. Also, the simple geometry of this phantom and the artificial skeleton allows us to simulate the neutron activation process using a Monte Carlo code, which enables us to calibrate the system for human subjects larger and smaller than the phantoms used as standards.
Topics: Body Composition; Bone and Bones; Calcium; Gamma Rays; Humans; Models, Anatomic; Monte Carlo Method; Neutron Activation Analysis; Phantoms, Imaging
PubMed: 8668109
DOI: 10.1118/1.597718 -
Journal of Nuclear Medicine : Official... Jul 1963
Topics: Activation Analysis; Blood Chemical Analysis; Computers; Electronic Data Processing; Humans; Radiometry
PubMed: 14044112
DOI: No ID Found -
Journal of Animal Science Jul 1975
Topics: Activation Analysis; Animal Feed; Animals; Cattle; Dysprosium; Feces; Half-Life; Medicago sativa; Neutron Activation Analysis; Radioisotopes
PubMed: 1158793
DOI: 10.2527/jas1975.411178x -
Casopis Lekaru Ceskych 1969
Review
Topics: Activation Analysis; Biology; Humans; Medicine; Radioisotopes
PubMed: 4885861
DOI: No ID Found