The adsorption behaviors of niobium and zirconium on silica gel and some other adsorbents were investigated in various concentrations of nitric acid or hydrochloric acid. Niobium is strongly adsorbed on silica gel in a concentrated nitric acid solution, while zirconium is not. In a concentrated hydrochloric acid solution, niobium is weakly adsorbed. Based on the results, a new simple separation method of niobium from other radionuclides especially zirconium is developed. In this method, niobium can be recovered by 81%, and separation from zirconium is complete. The method was applied to separation of radioniobium from the neutron-irradiated zirconium wire and from the neutron-irradiated uranium with the results of complete elimination of other radionuclides present.
The elemental contents of tree rings can reflect annual variation in an environment. The radial distributions of Sb content in the stems were analysed for akamatsu (P, densiflora), konara (Q. serrata) and sugi (C. japonica) grown on the Sb-polluted soil. In the same way those of Cu content were also determined for akamatsu, ryoubu (C. barbinervis) and sugi grown on the Cu-polluted soil. It was found that among these woody plants a sugi stem was available for the Sb-indicator and an akamatsu stem for the Cu-indicator, respectively.
A simulation study to evaluate the errors in rate constants of in the three compartment model using the weighted integral method was performed. Ten combinations of 7 kinds of weight functions, the errors were tested in18F fluorodeoxyglucose (18FDG) study. The error factors arisen in PET measurement were statistical noise, cerebral blood volume, time shift and scanning time of PET measurement. Errors in each rate constant was within the range of 10 percent and those in k1k3/ (k2+k3) within 1 percent. The weighted integral method was confirmed to be faster method than the conventional least squares method within reasonable error range.
The suitability of individual MAb for application in vivo should be carefully confirmed. The monoclonal antibody GL-013, with specific binding reactivity in vitro to human tumors of the gastrointestinal tract, was radioiodinated and injected intraperitoneally into nude mice bearing human gastric carcinoma xenografts SY 86 B (moderately differentiated glandular adenocarcinoma) and SY 86 D (signet ring cell carcinoma) . Whole body scintigraphy indicated tumor localization with131I-labeled MAb GL-013, but not with131I-labeled normal mice immunoglobulin. The best tumor contrast was obtained between days 3 and 7 after injection. As confirmation of the imaging results, 131I-GL-013 preferentially localized in tumor tissue compared with normal tissue and131I-GL-013 gave a higher tumor uptake ratio than the control131I-NMIgG (at day 9 after injection), as determined by tissue counting of radioactivity. These results demonstrate that MAb GL-013 localizes in xenografts SY 86 B and SY 86 D and the possible clinical application of MAb GL-013 to radioimmunolocalization.
The instrumental neutron activation analysis has been applied to the multielemental analysis of eight samples of the Ko-Kutani ware including the Aote's that is one of semi-porcelain body. Each sample was compared with concentration of the useful index element, such as Ta, Sc, Ba, Hf, Th and rare earth, to discriminate the Arita group from the Kutani group. Eight samples were judged as products of the Arita, just as in previous paper.
Radioprotective effect has been observed in mice which have subcutaneously received a single dose of abundant inorganic zinc or manganese 24 hours before γ-ray irradiation with a sublethal dose. Mechanism of the radioprotection has been suggested to be an abundant production of metallothionein (MT) induced by the metals. But process of the protection might be more complicated because immunological and hematopoietic functions are remarkably inhibited by the irradiation and many zinc binding-compounds with biological functions are known at present. Furthermore, the effect of these metals has been observed by the administration only before the irradiation. Radioprotective effect was shown in mice which were administered with not only zinc and manganese, but also magnesium. It seems that mechanism of the radioprotection of magnesium is different from that of zinc or manganese since magnesium is not known to induce MT production. It was observed that the relative concentration ratio of radioactivity in tissues and organs at 7th day (after injection of65Zn) showed a marked difference between in irradiated and non-irradiated mice.
Twenty subjects inhaled C15O and its dynamics were monitored to determine when equi-librium between the aorta and kidney occurred. One minute after inhalation, the increase in radioactivity in the aorta paralleled that in the kidney, but thereafter, both declined slowly. The ratio of aorta/kidney radioactivity become constant 1 min after inhalation and remained unchanged for 4 min. Thus renal blood volume can be measured 1 min after inhalation of C15O its distribution in the aorta and kidney has attained equilibrium.
A method for evaluating 1 cm dose equivalent rates from a pulse height distribution obtained by a 76.2mmφ spherical NaI (Tl) scintillation spectrometer was described. Weak leakage radiation from nuclear facilities were also measured and dose equivalent conversion factor and effective energy of leakage radiation were evaluated from 1cm dose equivalent rate and exposure rate.