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Yamashita, Takuma*; Iwami, Satone*; Mitsuyasu, Yusuke*; Ono, Kenta*; Oka, Toshitaka; Takahashi, Atsushi*; Kino, Yasushi*; Sekine, Tsutomu*; Shimizu, Yoshinaka*; Chiba, Mirei*; et al.
KEK Proceedings 2024-6, p.85 - 90, 2024/12
To clarify the radiation effects of the accident at the TEPCO's Fukushima Daiichi NPP on living organisms, it is important to accurately estimate the dose to each individual. We have developed a multi-component analysis program using random number optimization to extract only the components derived from carbonate radicals from the ESR spectra.
Iwami, Satone*; Yamashita, Takuma*; Mitsuyasu, Yusuke*; Ono, Kenta*; Oka, Toshitaka; Takahashi, Atsushi*; Kino, Yasushi*; Sekine, Tsutomu*; Shimizu, Yoshinaka*; Chiba, Mirei*; et al.
KEK Proceedings 2024-6, p.91 - 95, 2024/12
We aim to improve the detection limit of the ESR dosimetry method. In this study, the saturation behavior of each radical was investigated by varying the microwave power during ESR measurement. Based on the difference in spin relaxation time between carbonate radicals and native radicals, it is expected that the signal-to-noise ratio improves and the detection limit can be lowered when the microwave power is increased to 4.0 mW.
Mitsuyasu, Yusuke*; Oka, Toshitaka; Takahashi, Atsushi*; Kino, Yasushi*; Okutsu, Kenichi*; Sekine, Tsutomu*; Yamashita, Takuma*; Shimizu, Yoshinaka*; Chiba, Mirei*; Suzuki, Toshihiko*; et al.
Radiation Protection Dosimetry, 199(14), p.1620 - 1625, 2023/09
Times Cited Count:1 Percentile:34.39(Environmental Sciences)We have been conducting dose assessments for Japanese macaques captured in Fukushima to reveal radiobiological effects on the low-dose expose animals. To accurately determine the external exposure dose, it is desirable to examine the analysis of the CO radical intensity. We examined ESR spectra of teeth of 10 macaques captured in Fukushima by two spectrum-decomposition algorithms.
Mitsuyasu, Yusuke*; Oka, Toshitaka; Takahashi, Atsushi*; Kino, Yasushi*; Okutsu, Kenichi*; Sekine, Tsutomu*; Yamashita, Takuma*; Shimizu, Yoshinaka*; Chiba, Mirei*; Suzuki, Toshihiko*; et al.
KEK Proceedings 2022-2, p.120 - 125, 2022/11
We investigate the effect of sample's anisotropy and measurement condition to obtain the higher reproducibility for the shape of the ESR spectrum and the intensity of CO radical.
Oka, Toshitaka; Takahashi, Atsushi*; Koarai, Kazuma; Kino, Yasushi*; Sekine, Tsutomu*; Shimizu, Yoshinaka*; Chiba, Mirei*; Suzuki, Toshihiko*; Osaka, Ken*; Sasaki, Keiichi*; et al.
Journal of Radiation Research (Internet), 63(4), p.609 - 614, 2022/07
Times Cited Count:3 Percentile:41.23(Biology)Electron spin resonance (ESR) dosimetry is one of the most powerful tools for radiation dose reconstruction. The detection limit of this technique using human teeth is reported to be 56 mGy or 67 mGy; however, the absorbed dose of Fukushima residents after the Fukushima Daiichi Nuclear Power Plant (FNPP) accident was estimated to be lower than this detection limit. Our aim is to assess the absorbed radiation dose of children in Fukushima Prefecture after the accident; therefore, it is important to estimate the detection limit for their teeth. The detection limit for enamel of deciduous teeth of Japanese children separated by the mechanical method is estimated to be 115.0 mGy. The density separation method can effectively separate enamel from third molars of Japanese people. As we have collected thousands of teeth from children in Fukushima, the present technique may be useful to examine their external absorbed dose after the FNPP accident.
Mitsuyasu, Yusuke*; Oka, Toshitaka; Takahashi, Atsushi*; Koarai, Kazuma; Kino, Yasushi*; Okutsu, Kenichi*; Sekine, Tsutomu*; Yamashita, Takuma*; Shimizu, Yoshinaka*; Chiba, Mirei*; et al.
KEK Proceedings 2021-2, p.91 - 96, 2021/12
We examined whether the ESR dose estimation method could be applied to wild Japanese macaque. In this work, we investigated the enamel preparation protocol and the analytical method of the ESR spectra.
Koarai, Kazuma; Matsueda, Makoto; Aoki, Jo; Yanagisawa, Kayo*; Terashima, Motoki; Fujiwara, Kenso; Kino, Yasushi*; Oka, Toshitaka; Takahashi, Atsushi*; Suzuki, Toshihiko*; et al.
Journal of Analytical Atomic Spectrometry, 36(8), p.1678 - 1682, 2021/08
Times Cited Count:7 Percentile:57.15(Chemistry, Analytical)Rapid analysis of Sr in bone and tooth samples of cattle were achieved by an inductively coupled plasma mass spectrometry (ICP-MS) coupled with mass shift and solid phase extraction techniques. Limit of detection (LOD) in the ICP-MS measurement of 0.1 g samples was lower than that of the radioactivity measurement. Analytical time of the ICP-MS method was reduced from 20 days to 11 hours, compared with the radiometric method. Therefore, the ICP-MS method can be rapid and useful procedure of
Sr in small bone and tooth samples derived from terrestrial animals.
Kawasaki, Riku*; Sasaki, Yoshihiro*; Nishimura, Tomoki*; Katagiri, Kiyofumi*; Morita, Keiichi*; Sekine, Yurina; Sawada, Shinichi*; Mukai, Sadaatsu*; Akiyoshi, Kazunari*
Advanced Healthcare Materials, 10(9), p.2001988_1 - 2001988_8, 2021/05
Times Cited Count:11 Percentile:59.49(Engineering, Biomedical)Systems for "protein transduction", the intracellular delivery of functional proteins, are needed to address the deliverability challenges of protein therapy, but protein transfer in vivo remains difficult. In this study, we have developed a magnetically induced in vivo protein transfection system using a magnetic nanogel chaperone (MC) composed of iron oxide nanoparticles and polysaccharide nanogels. Experiments using an oral cancer model have shown that this MC system is useful for cancer treatment.
Takahashi, Atsushi*; Chiba, Mirei*; Tanahara, Akira*; Aida, Jun*; Shimizu, Yoshinaka*; Suzuki, Toshihiko*; Murakami, Shinobu*; Koarai, Kazuma; Ono, Takumi*; Oka, Toshitaka; et al.
Scientific Reports (Internet), 11(1), p.10355_1 - 10355_11, 2021/05
Times Cited Count:9 Percentile:44.37(Multidisciplinary Sciences)Oka, Toshitaka; Takahashi, Atsushi*; Koarai, Kazuma; Mitsuyasu, Yusuke*; Kino, Yasushi*; Sekine, Tsutomu*; Shimizu, Yoshinaka*; Chiba, Mirei*; Suzuki, Toshihiko*; Osaka, Ken*; et al.
Radiation Measurements, 134, p.106315_1 - 106315_4, 2020/06
Times Cited Count:9 Percentile:67.98(Nuclear Science & Technology)The relationship between the CO radical intensity and the absorbed dose (dose response curve) of tooth enamel of Japanese macaque was observed by electron spin resonance and the detection limit of our system was estimated to be 33.5 mGy, which is comparable to the detection limit for human molar teeth. Using the dose response curve, external exposure dose for seven wild Japanese macaques captured in Fukushima prefecture were examined. The results suggest that the external exposure dose for the wild Japanese macaques were ranged between 45 mGy to 300 mGy.
; Onuki, Toshihiko; Isobe, Hiroshi; Yanase, Nobuyuki; Sekine, Keiichi; ;
Journal of Contaminant Hydrology, 35, p.191 - 199, 1998/00
Times Cited Count:4 Percentile:18.57(Environmental Sciences)no abstracts in English
Yanase, Nobuyuki; Sato, Tsutomu; ; Sekine, Keiichi
Radiochimica Acta, 82, p.319 - 325, 1998/00
no abstracts in English
Onuki, Toshihiko; Yanase, Nobuyuki; Sekine, Keiichi; Isobe, Hiroshi; Nagano, Tetsushi; Sakamoto, Yoshiaki
Journal of Nuclear Science and Technology, 34(12), p.1153 - 1158, 1997/12
Times Cited Count:27 Percentile:86.43(Nuclear Science & Technology)no abstracts in English
Sekine, Keiichi; Muraoka, Susumu; Bamba, Tsunetaka
JAERI-Review 97-007, 61 Pages, 1997/03
no abstracts in English
Sekine, Keiichi; Muraoka, Susumu; Bamba, Tsunetaka
JAERI-Review 96-005, 97 Pages, 1996/03
no abstracts in English
Yanase, Nobuyuki; Sato, Tsutomu; Isobe, Hiroshi; Sekine, Keiichi
Hoshasei Haikibutsu Kenkyu, 2(1-2), p.121 - 135, 1996/02
no abstracts in English
Nakayama, Shinichi; Yamaguchi, Tetsuji; Sekine, Keiichi
Radiochimica Acta, 74(1), p.15 - 19, 1996/01
no abstracts in English
H.M.Garnett*; P.L.Airey*; Sekine, Keiichi; P.-S.Hahn*; W.R.Ott*; C.Pescatore*
10th Pacific Basin Nuclear Conf. (10-PBNC), 2, p.1335 - 1342, 1996/00
no abstracts in English
; Sato, Tsutomu; Nagano, Tetsushi; Yanase, Nobuyuki; Yamaguchi, Tetsuji; Isobe, Hiroshi; Onuki, Toshihiko; Sekine, Keiichi
JAERI-Review 95-011, 94 Pages, 1995/07
no abstracts in English
Yanase, Nobuyuki; T.E.Payne*; Sekine, Keiichi
Geochemical Journal, 29, p.1 - 29, 1995/00
Times Cited Count:25 Percentile:48.62(Geochemistry & Geophysics)no abstracts in English