Authors:S. Watanabe, T. Katabuchi, N. Ishioka, S. Matsuhashi, and H. Muramatsu
Endohedral 133Xe-higher fullerenes (133Xe@C76 and 133Xe@C84) were produced by implantation of 133Xe ions using an isotope separator. A high performance liquid chromatography (HPLC) analysis showed that the peak of endohedral
133Xe-higher fullerenes shifted backward from that of empty fullerenes, suggesting a possibility of the separation of endohedral
133Xe-higher fullerenes from empty fullerenes. The yields of endohedral 133Xe-fullerenes were in the order of 133Xe@C76<133Xe@C84<133Xe@C60<133Xe@C70.
Authors:S. Amachi, Y. Muramatsu, H. Shinoyama, and T. Fujii
An efficient method for the isolation of iodine-accumulating bacteria was established. A total number of 138 bacterial strains
were grown on agar media containing 125I, and the strains having strong radioactivity were chosen by autoradiography. They were then grown in liquid media containing
125I, and the radioactivity of the cells and the supernatants was determined after centrifugation through silicone oil. Eight
strains were found to remove 78 to 90% of iodine from the media within 24 hours, and corresponding amount of iodine was detected
in their cells. The advantage of this method is in its simplicity and the low detection limit.
Authors:S. Yoshida, Y. Muramatsu, S. Katou, and H. Sekimoto
An online analytical system using ion chromatography (IC) followed by inductively coupled plasma mass spectrometry (ICP-MS)
was developed for the separate determination of I− and IO3− in aqueous solutions with a detection limit 0.1–1 μg 1/1. The total iodine concentration was also directly determined by
ICP-MS. Iodine in several environmental samples (i.e., rain, river water, brine, and soil solution) was successfully determined
with information on its chemical form. The release of I− into soil solution with decreasing Eh was observed in an incubation experiment with flooded soil. An iodine form other than
I− and IO3− was observed in several environmental samples.
Authors:S. Watanabe, N. S. Ishioka, T. Sekine, H. Kudo, H. Shimomura, H. Muramatsu, and T. Kume
Hydrophilic endohedral 133Xe-fullerenols, [133Xe@C60(OH)xand 133Xe@C70(OH)x], were synthesized from hydrophobic endohedral 133Xe-fullerenes. The yield of endohedral 133Xe-fullerenols extracted in water was about 40% and 23% for C60and C70, respectively. The products stored in 0.9% NaCl solution at 20 °C were stable enough to be used in nuclear medicine.
Authors:S. Watanabe, N. Ishioka, T. Sekine, A. Osa, M. Koizumi, H. Shimomura, K. Yoshikawa, and H. Muramatsu
Ion implantation was applied to the production of endohedral 133Xe-fullerene. Using an isotope separator, 133Xe ions were implanted into a fullerene target of C60 and C70 produced by vacuum evaporation on a Ni backing. An HPLC analysis following dissolution of the fullerene targets in o-dichlorobenzene corroborated the formation of 133Xe@C60 and 133Xe@C70, showing a strong correlation between C60/C70 and 133Xe. The observed tailing following 133Xe peaks in the elution curves suggests a possibility of the isolation of endohedral 133Xe-fullerene from empty fullerene.
Authors:H. Muramatsu, S. Yoshizawa, T. Abe, T. Ishii, M. Wada, Y. Horiuchi, and R. Kanekatsu
The concentration of 7Be in surface air at Nagano City has been measured during the period from August 2000 to March 2005. The average monthly concentrations
of 7Be in surface air were in the range of 3.3–14 mBq/m3 with pronounced two peaks in spring and autumn. It took 30–40 hours to recover the 7Be concentrations observed before, once 7Be was washed out by wet precipitations. For a pronounced increase in the concentrations of 7Be found in winter, a low-pressure trough coming close to the Japanese Islands with high concentrations of 7Be is responsible under the characteristic distribution of atmospheric pressure around the Japanese Islands.
Authors:A. Shinohara, T. Muroyama, T. Miura, A. Yokoyama, K. Takamiya, T. Kaneko, T. Saito, J. Sanada, H. Araki, S. Kojima, Y. Hamajima, H. Muramatsu, H. Baba, and M. Furukawa
Pionic X-rays and π0 decays were measured for gas mixtures of H2/D2/CH4+SF6/Ar and the individual pure gases. Chemical effects on the pion transfer process from pionic hydrogen to other atoms were
revealed by the pionic X-ray spectrum. The changes of the intensity patterns of pionic X-rays were compared with the predictions
by a cascade calculation taking the transfer process into account. The mechanism of pion transfer process was discussed based
on the results for gas phase and the previous ones for liquid phase.
Authors:H. Muramatsu, H. Ishii, E. Tanaka, M. Misawa, H. Ito, T. Miura, S. Muto, M. Koizumi, A. Osa, T. Sekine, and M. Yanaga
Mössbauer effect measurements for the 81 keV transition in133Cs have been performed with133Xe-implanted sources prepared by means of an electromagnetic isotope separator. The behavior of the isomer shift of133Cs impurities was studied in various metals. Some correlations were found between measured isomer shifts and electronic properties
of the host materials, and they show that the host conduction electrons have an important role in the determination of the
isomer shift in metals.
Authors:T. Muroyama, A. Shinohara, T. Saito, A. Yokoyama, K. Takamiya, S. Morimoto, K. Nakanishi, H. Baba, T. Miura, Y. Hamajima, T. Kaneko, H. Muramatsu, S. Kojima, and M. Furukawa
Annihilation γ-rays of π0 and pionic X-rays were measured in the gas mixtures of H2+Z and CH4+Z systems (Z=He, Ne, Ar and Kr). Pion capture probability of hydrogen atom was obtained from the annihilation γ-ray counts
and the capture probability of Z atom was obtained from the pionic X-ray intensities. Transfer rates were determined from
the data based on a combined large mesomolecular model. The transfer rates obtained were smaller than the systematics of the
Russian group. Difference in the transfer rate between the gas and the liquid phases was found by a comparison of the present
results with our previous ones.