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Yokoyama, Tatsunori; Kimura, Junichi*; Mitsuguchi, Takehiro; Danhara, Toru*; Hirata, Takafumi*; Sakata, Shuhei*; Iwano, Hideki*; Maruyama, Seiji*; Chang, Q.*; Miyazaki, Takashi*; et al.
Geochemical Journal, 52(6), p.531 - 540, 2018/12
Times Cited Count：14 Percentile：71.17(Geochemistry & Geophysics)
, induced by ionizing radiation in 
Kimura, Takafumi*; Takanami, Takako*; Sakashita, Tetsuya; Wada, Seiichi*; Kobayashi, Yasuhiko; Higashitani, Atsushi*
Radiation Research, 178(4), p.313 - 320, 2012/10
Times Cited Count：8 Percentile：44.94(Biology)Here, we found that exposure to ionizing radiation (IR) induce certain innate immune response gene of in the intestine. Pre-treatment with IR before seeding on 
lawn plate, significantly increased survival rate in the nematode. IR induction of gene was highly dependent on the ELT-2 transcription factor and p38 MAPK. Moreover, the insulin/IGF-1 signal pathway works as an enhancer of induction of this gene. Silencing of the gene led to growth retardation after IR irradiation. Finally, we describe the cross-tolerance between the responses to radiation exposure and innate immune system.
Wakai, Eiichi; Kikuchi, Takayuki; Kogawara, Takafumi; Kimura, Haruyuki; Yokomine, Takehiko*; Kimura, Akihiko*; Nogami, Shuhei*; Kurishita, Hiroaki*; Saito, Masahiro*; Nishimura, Arata*; et al.
Proceedings of 23rd IAEA Fusion Energy Conference (FEC 2010) (CD-ROM), 6 Pages, 2011/03
Japanese activities of test facilities in IFMIF-EVEDA (International Fusion Materials Irradiation Facility-Engineering Validation and Engineering Design Activities) project have three subjects of engineering design of post irradiation examination (PIE) facilities, small specimen test technique (SSTT), and engineering design of high flux test module (HFTM), and this paper is summarized about present status. Functional analysis and design of 2-D and 3-D models of PIE facility were performed. In HFTM, as materials of heater, W-3Re alloy and/or SiC/SiC composite were selected in the points of high temperature materials, fabrication technology and some suitable properties such as resistance of thermal shock, high temperature re-crystallization, ductility, resistance of irradiation degradation, and low-activation. In SSTT, a test machine of fracture toughness was designed and developed for small specimens with 10 mm square, and it had high accuracy controllability for stress and displacement.
Kimura, Atsushi; Taguchi, Mitsumasa; Kondo, Takafumi*; Yang, J.*; Nagaishi, Ryuji; Yoshida, Yoichi*; Hirota, Koichi
Radiation Physics and Chemistry, 79(11), p.1159 - 1164, 2010/11
Times Cited Count：3 Percentile：25.53(Chemistry, Physical)Much of this past research has focused on finding more effective reactions between charged reactive species in room temperature ionic liquid (RTILs), which have a coulombic field. Reactions in RTILs involving the charged reactive species, particularly solvated electrons, have been studied by the techniques of radiation chemistry. The reaction behavior of halophenols in RTILs were investigated by 
ray and pulsed electron radiolysis. The yield of CP decomposition in the RTILs was almost the same as that of solvated electrons formation. The yield of CP decomposition and phenol formation in the RTILs was low in the presence of electron scavengers such as nitrous oxide, indicating that solvated electrons primarily contributed to the decomposition of CP. The type of halogen group with the exception of fluorine had a negligible effect on the decomposition of halophenols in the RTILs. Therefore, RTILs could be applied as an reaction media for the reduction by ionizing radiation.
; Germ cell response, aging and behaviorSakashita, Tetsuya; Takanami, Takako*; Yanase, Sumino*; Hamada, Nobuyuki*; Suzuki, Michiyo; Kimura, Takafumi*; Kobayashi, Yasuhiko; Ishii, Naoaki*; Higashitani, Atsushi*
Journal of Radiation Research, 51(2), p.107 - 121, 2010/03
Times Cited Count：31 Percentile：63.94(Biology)The study of radiation effect in 
have been carried out over three decades and now allow for understanding at the molecular, cellular and individual levels. This review describes the current knowledge of the biological effects of ionizing irradiation with a scope of the germ line, aging and behavior. 
may be a good 
model system in the field of radiation biology.
Kimura, Atsushi; Taguchi, Mitsumasa; Kondo, Takafumi*; Yang, J.*; Yoshida, Yoichi*; Hirota, Koichi
Radiation Physics and Chemistry, 77(10-12), p.1253 - 1257, 2008/10
Times Cited Count：10 Percentile：58.26(Chemistry, Physical)
Higashitani, Atsushi*; Mori, Chihiro*; Kimura, Takafumi*; Ikenaga, Takahiko*; Takanami, Takako*; Sakashita, Tetsuya; Wada, Seiichi*; Hamada, Nobuyuki*; Kobayashi, Yasuhiko
JAEA-Review 2007-060, JAEA Takasaki Annual Report 2006, P. 112, 2008/03
We investigated the gene expression of following carbon and irradiation using DNA microarray analysis. We observed the 187 and 297 upregulated genes after and carbon irradiation with 100 Gy, respectively, in which 51 genes were upregulated following both irradiations. On the other hand, the 358 and 388 genes were downregulated after and carbon irradiation, respectively.
Taguchi, Mitsumasa; Kimura, Atsushi; Kondo, Takafumi*; Yang, J.*; Yoshida, Yoichi*; Hirota, Koichi
no journal, ,
no abstracts in English
Kimura, Atsushi; Taguchi, Mitsumasa; Hirota, Koichi; Kondo, Takafumi*; Yang, J.*; Yoshida, Yoichi*
no journal, ,
no abstracts in English
Kimura, Atsushi; Taguchi, Mitsumasa; Kondo, Takafumi*; Yang, J.*; Yoshida, Yoichi*; Hirota, Koichi
no journal, ,
no abstracts in English
-ray and pulsed electron radiolysis studies on the reaction of solvated electrons in room temperature ionic liquids of alkylammonium saltsKimura, Atsushi; Taguchi, Mitsumasa; Kondo, Takafumi*; Yang, J.*; Yoshida, Yoichi*; Hirota, Koichi
no journal, ,
no abstracts in English
Kimura, Atsushi; Kondo, Takafumi*; Yang, J.*; Nagaishi, Ryuji; Yoshida, Yoichi*; Taguchi, Mitsumasa
no journal, ,
no abstracts in English
Kimura, Atsushi; Taguchi, Mitsumasa; Kondo, Takafumi*; Yang, J.*; Nagaishi, Ryuji; Yoshida, Yoichi*
no journal, ,
no abstracts in English
Kimura, Atsushi; Kondo, Takafumi*; Yang, J.*; Nagaishi, Ryuji; Yoshida, Yoichi*; Taguchi, Mitsumasa
no journal, ,
no abstracts in English
Wakai, Eiichi; Kogawara, Takafumi; Kikuchi, Takayuki; Yamamoto, Michiyoshi; Molla, J.*; Kimura, Akihiko*; Kasada, Ryuta*; Kim, B.*; Nogami, Shuhei*; Hasegawa, Akira*; et al.
no journal, ,
no abstracts in English
Motooka, Takafumi; Suzuki, Miho; Tomita, Takeshi; Kimura, Yasuhiko; Ueno, Fumiyoshi
no journal, ,
To investigate the migration of seawater components to a spent fuel cladding tube, cross-sectional observation for spent fuel cladding tube immersed in diluted artificial seawater at 80 for 300 hours was conducted with EPMA. Spent fuel cladding tube having crud layer and zirconium oxide layer showed the adhesion of seawater components (Mg, Cl) on the cladding and no penetration of seawater components into the cladding.
Motooka, Takafumi; Suzuki, Kazuhiro; Suzuki, Miho; Toyokawa, Takuya; Kimura, Yasuhiko
no journal, ,
Spent fuels were stored in the spent fuel pool (SFP) at the Fukushima Daiichi Nuclear Power Plant. Seawater was injected into SFP to cool spent fuels for emergency measure in the Fukushima Daiichi Nuclear Accident. Seawater can cause local corrosion. The purpose of this study is to investigate the effect of seawater on corrosion behavior and mechanical property of the spent fuel cladding. We immersed short spent fuel cladding tubes (
50 GWd/t) in artificial seawater at 353 K for 300 h and conducted visual, metallographic and strength examinations of the tubes after immersion. Visual and metallographic examination indicated that warm seawater little affected the corrosion behavior of the spent fuel cladding. Black oxides formed on the surface of the cladding during the reactor operation were observed. No local corrosion and crack were observed. Ultimate tensile strength (UTS) and 0.2% yield strength (0.2%YS) of tubes with and without immersion in artificial seawater at 353 K for 300 h were measured. The strength of immersed tube was comparable to that of non-immersed tube. The results suggest that the seawater injection little affects on corrosion behavior and mechanical property of the spent fuel cladding.
Yokoyama, Tatsunori; Kokubu, Yoko; Murakami, Hiroaki; Hirata, Takafumi*; Sakata, Shuhei*; Danhara, Toru*; Iwano, Hideki*; Chang, Q.*; Kimura, Junichi*
no journal, ,
The chronological information about carbonates is useful for modeling and enables forecast of geological and geochemical environmental changes by simulating. The U-Th-Pb dating method for carbonates which were formed at reducing environment remain to be established. The final goal of our study is to establish in situ U-Th-Pb dating method for carbonates which are filling cracks in pervious rock like fault rocks. In this study, the U-Th-Pb elemental and isotopic two-dimension distribution for an ammonite fossil were visualized by "Imaging" method using Laser-ablation ICP Mass Spectrometry. In U-Pb isotope analysis for carbonates in cracks of granites, we could not obtain significant U-Pb age data by the lack of uranium and influence of non-radiogenic common lead. When the concentration of lead is sufficiently high for the measurement, we obtained reliable isotopic data from carbonates and their lead isotopic composition reflected characteristic composition of their origin water.
Yokoyama, Tatsunori; Kokubu, Yoko; Murakami, Hiroaki; Watanabe, Takahiro; Hirata, Takafumi*; Sakata, Shuhei*; Danhara, Toru*; Iwano, Hideki*; Maruyama, Seiji*; Miyazaki, Takashi*; et al.
no journal, ,
Chronological and geochemical studies of carbonates, which are commonly found as fracture filling minerals in rocks, can provide information about geochemical conditions present during formation including in deep subsurface environments. A dating technique for the carbonates using laser ablation-multiple collector-inductively coupled plasma mass spectrometry (LA-MC-ICPMS) is still immature partly because of a lack of a consensus international carbonate standard for the in-situ dating technique. In this study, we performed a survey on the carbonate standard materials that may be suitable for high precision U-Th-Pb dating using LA-MC-ICPMS. We examined carbonate standard materials JCp-1 and JCt-1 issued by the Geological Survey of Japan (GSJ). Based on solution-based bulk analysis using MC-ICP-MS, heterogeneities in Pb isotope compositions were confirmed. Nevertheless, the 206Pb-based isotopic compositions were all within 1.2 per mill variations acceptable for a standard used for age determination using LA-MC-ICPMS. Additional tests on the heterogenities in U-Th-Pb compositions of the carbonate standards along with determinations of other trace elements using a 2D imaging LA-ICP-MS are ongoing. Examinations on both natural standards and synthetic standards are ongoing for further efforts in determination of the standard suitable for U-Th-Pb dating of carbonates.
Yokoyama, Tatsunori; Kokubu, Yoko; Mitsuguchi, Takehiro; Murakami, Hiroaki; Hirata, Takafumi*; Sakata, Shuhei*; Danhara, Toru*; Iwano, Hideki*; Maruyama, Seiji*; Chang, Q.*; et al.
no journal, ,
no abstracts in English
