We present the preparation of 28Mg to study Mg uptake manner by rice root. Since there is no convenient Mg tracer, we prepared 28Mg from a pure Al target irradiated by an α-particle beam. As a result, approximately 1MBq of carrier-free and salt-free 28Mg was purified. Mg uptake velocity of rice was analyzed using seedlings at the third-, fourth- and seventh-leaf stages. Prepared 28Mg was applied to the rice root for a short term (15 to 30min) with low (0.1mM) or high (5.0mM) concentration of Mg in a solution. After sample was washed with cold water, 28Mg distribution was detected by an imaging plate. From the analysis, the Mg uptake rate of the root in the 5.0mM Mg was approximately 6 to 7-fold higher than that in the 0.1mM. To confirm the result more in detail, the uptake analysis was also performed with various concentrations of Mg. The results indicate that Mg uptake systems concentrate Mg when the Mg concentration in the external solution is low, which suggests the high contribution of active Mg transport system in root.
The objective was to obtain data for the improvement of procedures of 18F-FDG PET/CT examination by performing questionnaire survey just before PET/CT examination with regard to explanation of the examination. One hundred cancer patients without an experience of PET/CT examination were enrolled in this study. The questionnaire survey suggested that the facility, amenities, and PET/CT study procedures should be improved in some aspects. It is effective for removal of patients'uneasiness to explain the PET/CT examination in more detail just before the examination.
After 36days of Fukushima Daiici nuclear power plant accident, the surface of paddy soil and soils where rapeseed and wheat were grown was collected and the extraction of 131I, 134Cs and 137Cs was tried. About 20% of radioactive nuclides were extracted by the first treatment of water but the rest of the nuclides were not extracted by further extraction. In the case of paddy soil, the water containing KI, CsI, fertilizer, calcium hydroxide and cement was tried to extract the radioactive nuclide. The extraction rate was about the same as that by water alone.
Radioactivity imaging and radioactivity measurement of 134Cs and 137Cs were performed for a wheat plant grown in Fukushima, after about 2 months of Fukushima Daiichi nuclear accident. The radioactivity was about 100 times higher in the withered leaves (about 300kBq/kg) than new leaves(about 3kBq/kg). The radioactivity was the lowest in panicles. The images by an imaging plate showed that the high radioactivity was found as many spots in the old leaves, suggesting that the radionuclides are strongly adhered to the leaves.
Concentration profiles of 134Cs and 137Cs were obtained in an undisturbed paddy field before plowing in Fukushima prefecture on May 24th, 2011, about two month after explosions of Fukushima Daiichi nuclear power plant. Top soil of 0 - 15cm was sampled, by separating it into 6 layers of 1 - 5cm thick. Resulting concentration profile indicates that 88% of 134Cs+137Cs existed within 0 - 3cm and 96% within 0 - 5cm layer. However, although most of radioactive Cs stays within a few cm surface layer, a part of it already reached 10 - 15cm layer. Mean travel distance of 134Cs and 137Cs were calculated from the profile to be 1.74cm;on the other hand, mean travel distance of water molecules during the 70days was also estimated as [precipitation - evaporation]/[volumetric water content] to be about 20cm. Therefore, convective velocity of Cs was 1/10 of water due to sorption of Cs on soil. However, this ratio of Cs velocity is 2 - 3 order greater than that calculated from soil-soil solution distribution coefficients(Kd) for soils of Japanese paddy field shown in a literature, indicating that the movement of Cs in the field occurs in condition far from sorption equilibrium.
After the accident of Fukushima nuclear power plant, vegetables were grown at an experimental farm of Nishi-Tokyo City in Tokyo, which was located about 230km away from the power plant. The outer leaves of cabbages and leaves of potatoes were taken after 47 and 40 days, respectively, and the radioactivity of 134Cs and 137Cs was measured. The total radioactivity of 134Cs and 137Cs in both plants was less than 9Bq/kg, which was far lower than that of the regulated value, 500Bq/kg, for human to intake. The radioactivity of soil was about 130Bq/kg, less than that of the natural activity of 40K, about 290Bq/kg. The difference of the radioactivity image of cabbage outer leaves, washed and without washing, was not observed using an imaging plate.
The radioactivity of 131I, 134Cs and 137Cs in soil, milk as well as pasture (Italian ryegrass) and well water supplied to the cows was measured. The samples were collected from Animal resource science center located at Ibaraki-prefecture, about 130km south of Fukushima nuclear power plant, 3 and 12 weeks after the accident. It was found that the radioactive nuclides included in meadow grass were promptly transferred to the milk. But the radioactivity of these nuclides were lower than the provisional government regulated value, 300 and 200Bq/kg for radioactive I and Cs, respectively.
A questionnaire survey on safety of nuclear medicine studies was conducted under the subcommittee for radionuclide imaging and nuclear medicine technology of Japan Radioisotope Association to promote patient safety. Questionnaires sheets were sent to 1288 hospitals and 14 clinical laboratories in Japan with valid responses from 1016 facilities (78.0%). The number of accidents and incidents decreased to 53.3% of those of 2001, due mainly to the decrease in the number of incidents. Incidents due to errors in handling of the imaging apparatus was markedly decreased compared with the last survey. Accidents and incidents due to bump/contact by cameras decreased markedly. About a half of the accidents was attributable to incorrect handling of the patients. The number of system malfunction and break of cameras decreased to 39.2% of those in 2004. The results may indicate that 70% of incidents and accidents is prevented by concise explanation, meticulous care of patients and re-education of safety precautions to workers in nuclear medicine facilities. Improvement in the fixation device of patients and preparation of safety manual were regarded as important for promoting safety in nuclear medicine practice.