Chemical forms of radioactive iodine and its effects upon marine organisms were studied by the tracer experiments. Seaweeds or fish were held in the aquarium in which the125I tracer in either iodide or iodate form was inoculated. Iodide form of125I was taken by Dorome (Chasmichthys gulosus) with the concentration factor of about 10 and excreted with the biological half-life of 15 days, while iodate form of125I was not taken up appreciably and the concentration factor did not greatly exceed unity. Uptake and loss of125I were studied as well for 3 species of seaweeds, Hi jiki (Hizikia fusiforme), Nejimoku (Sargassum sagamianum) and Tsunomata (Chondrus ocellatus) . Iodate form of125I was accumulated less than iodide form by these seaweeds but the concentration factor of Iodate by these seaweeds was very high compared to those by fish.
Several methods to obtain the body contour which is necessary to reconstruct the quantitative images with single photon radionuclide computed tomography (SPRCT) are described in this paper. A multipurpose gamma camera system which is composed of 2 detectors, data pocessor and others were used to collect the data of SPRCT and body contour. An iterative reconstruction technique was implemented to reconstruct the image. Three methods for obtaining the body countour were tested. The first method utilizes X-ray CT data. The data which are obtained by GE CT/T are transfered to the data processor of SPRCT through the off-line magnetic tape and delineate the body contour. The second method uses a transmission source which was attached on the opposite side to detector. The third method uses 7-rays which are generated by Compton scatter in the tissue of patient. The first and the second methods were able to use to obtain the body contour, but the contour obtained by third method was not accurate.
The13C and15N abundances of the tissues of rats fed with a constant diet were measured by mass spectrometry. Isotopic discrimination was larger in15N than in13C compared to diet. The extents of discrimination of13C and15N differed depending on tissues, but highly correlated each other.
After γ-irradiating the nuclei isolated from dry seed-embryo of barley in the presence of varying concentrations of ethylene glycol, macromolecular DNA (deoxyribonucleic acid) was extracted from them. The yields of DNA was determined by the 2 methods. The both method of determination on DNA showed a similar tendency; the higher the exposed dose and the concentration of ethylene glycol, the better the yields.