Adsorption of uranium from carbonate solution onto organo-clay complex allowed to react with montmorillonite and dodecylammonium chloride, has been investigated by using various amines as a collector. Comparison of primary, secondary, tertiary and quarternary amines showed that the adsorption amount of uranium was greatest for the quarternary amine and least for the primary amine. Among quarternary amines, zephyramine is the best collector. It was found that the adsorption occurs remarkably at the narrow region of pH 6-8, and the pH dependence resulted from the uranyl species such as UO2+2, UO2 (CO3) 2-2, UO2 (CO3) 4-3, UO2 (OH) -3and so on. Little adsorption occurs at pH<5 and pH>9, because less zephyramine-uranil carbonato complex was formed in both pH ranges. On the other hand in the pH 6-8, uranium is adsorbed largely through hydrophobic interaction between the alkyl-chain of zephyramine-UO2 (CO3) n complex (n=2 or 3) and the organo-clay complex. Thus, hydrated alkylammonium-clay complex shows a useful absorbent for alkylamine-tricarbonate complex.
The spleen is the largest lymphoid organ. The uptake of14C-putrescine in spleen increased 5 to 8 days after inoculation of sarcoma-180 tumor cells. This phenomenon is in accord with the increase of spleen weight, and its uptake by teatment with DFMO increased about 2 times that of nontreatment with DFMO. A correlation between the spleen weight and14C-putrescine uptake in spleen is obtained. By i.p. administration of lentinan; immunopotentiator, the uptake of14C-putrescine in spleen was significantly increased. Putrescine would be useful for a splenic immunofunctional imaging agent.
Commercially available zener diodes have been tested as “high-temperature” dosimeters. They were heated above 50°C, and irradiated with 10-Me V electron beams and60Co γ-rays. For both radiations, the radiation-induced change in breakdown voltage of the zener diode when it is kept around 100°C have shown good linearity as a function of irradiated dose. It can be concluded from the present experiment that the zener diodes are promising candidates for dosimetry at temperatures above 50°C.
Germinating seeds of Glycine max (L.) cultivar. L-65 (Dr. W.G, variety) were treated with3H-thymidine at various times after seed soaking began at 25°C and the shoot apical meristem was squashed on slides. Then, microf luorography was carried out. The tritiumlabeled nuclei and mitoses were examined through the microscope. Consequently, it was suggested that most shoot apical meristem cells begin the DNA synthesis at 22-24 h after soaking of seed and lasts for 5 h, while mitosis starts at 26-28 h and the period is about 2.5 h. It was further supposed that shoot apical meristem cells stays at G0orG1period in the dormant seed.
Experiments were made to determine the energy dependence of CO3-3signal intensity in ESR dosimetry of tooth enamel. Packages containing 100 mg of mixed tooth enamel of particle size of 500-850μm were irradiated by X- or gamma-rays of various effective energies up to an exposure of about 1290×10-4 C/kg (500 R) . The irradiated tooth enamel samples were then subject to the ESR dosimetry and the relative response was determined as a function of effective photon energy. The response curve has a maximum at about 35 keV and is almost flat above 200 keV.