The exchange reactions of thiourea derivatives having -NH-C=S group with sodium hydrosulfide-35S or with elementary sulfur-35S were investigated. In all systems the exchange reaction occurred under the more drastic condition than that on dithiocarbamates. Thiol form as tautomer of these thiourea derivatives appeared to inhibit the exchange reaction. 35S labeled thiourea derivatives were isolated from the reaction mixtures.
Cyclic activation analysis method using241Am-Be neutron source was studied to determine the fluorine content. In order to effectively accumulate the counting value of the induced nuclide, the time for neutron burst, for counting and for sample transport considering the half life of induced nuclide were discussed. See saw type and pneumatic tube type cyclic activation analysis systems were deviced to accumulate the activity of16N produced by (n, α) reaction. Applying the result, the fluorine content of several kinds of fluorine plastics containing various kind of fillers was determined. The result obtained by cyclic activation method agreed with that by chemical analysis.
It is well known that non-metallic inclusion in the steel such as oxide and sulfide has affected on the some mechanical property of the steel. At present, the content of oxide inclusion in the steel on the decrease with development of vacuum refining and casting. However, it seems to be difficult to the decrease sulfide inclusion in the steel even with method above mentioned. Up to this time, many study was reported as to the cause of the origination of the segregation of the sulphur and other elements in the steel. There was few report which researched relation between segregation and casting structure through the solidification process. We studied relation between segregation of the sulphur and casting structure through the solidification process to the sulphur content 0.025% to 0.060% in the steel by the aid of autoradiography. For the purpose above mentioned, we made trial the mold combined cooling box and heating box. Consequently, we found experimentally that the factor which influenced segregation of the sulphur was as solidification velocity and uniformly solidification process in all parts of the mold as casting structure.
In order to investigate the uptake into the tumor and the form of chemical bond in the tumor tissue, the uptake of169Yb, 67Ga and111In into the tumor and the various organs was assayed at 10, 30, 60 and 120 minutes after i.v. injection, using the rats subcutaneously transplanted with Yoshida sarcoma. In these experiments, the uptake rate of169Yb in the tumor was already reached to 70% of saturated value at ten minutes post-injection, that of67Ga was reached to 50% of this value, and that of111In was already saturated at this time. From these results, it became clear that169Yb, 67Ga and 111In were rapidly taken up into the tumor, and these elements taken up into the tumor were not excreted out of the tumor. And it is a well-known fact that169Yb, 67Ga and 111In are not sulfur coordinator and the weak nitrogen coordinator. Considering the above-described facts theoretically, it is presumed that the chemical bond of these elements (the elements of group III in the periodic table) was not chelate ring, but ionic bond. In the organs of the animals, there are large amounts of carboxyl radical, phosphoryl radical and sulfonic group and it might be reasonable to take them as the sites with which Yb+++, Ga+++and In+++could be combined.
The authors applied dual-radioisotope techniques (subtraction techniques) to lung cancer as tumor scanning, using197HgCl2and131I-RISA and some basic experiments were performed. They showed that detecting ability of the lesion was increased and clinically, good results were obtained. The advantage and disadvantage of this method were discussed.
Renal scintigraphy by197Hg-chlormerodrin was fundamentally and clinically studied. The effect of low energy of197Hg X-rays on scintigraphy was studied with phantom experiment, as compared with203Hg. There was almost no difference up to 5cm of absorption layer between them. Slight effect of scattering was observed in 10 cm of absorption layer. The degree of decrease of counting rate due to absorption did not almost change up to 5 cm. In 10cm, the counting rate of197Hg decreased to 30±5%, as compared with 55±5% of203Hg. Renal scintigraphy with197Hg-chlormerodrin was clinically done in 21 cases. The scan picture obtained with197Hg-chlormerodrin was almost similar to that with203Hg-chlormerodrin. It was emphasized that this radiopharmaceutical should be widely used to decrease exposure dose to the kidney.
Diagnostic approach was done in 92 cases with renal scintiscanning with197Hg-chlormerodrin. Especially, differential diagnosis in space occupying lesions such as renal tumor, renal cyst, renal tuberculosis, and metastatic retroperitoneal tumor was clinically analysed. These diseases might have no characteristic pattern on the scintigrams, but some characteristic pictures were obtained in many cases. In addition, the scintigrams of other renal diseases were mentioned. Diagnostic significance was observed in not only space occupying lesion, but also malformation, renal insufficiency and vascular diseases. As197Hg has low energy, it was safe in exposure dose, and there was no side effect. Scintigram is superior for resolution, and is applicable for side diagnostic method. However, over-estimation on diagnosis using this method should not be made.