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Nishimura, Katsuhiko*; Matsuda, Kenji*; Lee, S.*; Nunomura, Norio*; Shimano, Tomoki*; Bendo, A.*; Watanabe, Katsumi*; Tsuchiya, Taiki*; Namiki, Takahiro*; Toda, Hiroyuki*; et al.
Journal of Alloys and Compounds, 774, p.405 - 409, 2019/02
Times Cited Count:3 Percentile:17.96(Chemistry, Physical)Suzuki, Yohei*; Konno, Yuta*; Fukuda, Akari*; Komatsu, Daisuke*; Hirota, Akinari*; Watanabe, Katsuaki*; Togo, Yoko*; Morikawa, Noritoshi*; Hagiwara, Hiroki; Aosai, Daisuke*; et al.
PLOS ONE (Internet), 9(12), p.e113063_1 - e113063_20, 2014/12
Times Cited Count:12 Percentile:34.33(Multidisciplinary Sciences)We present multi-isotopic evidence of microbially mediated sulfate reduction in a granitic aquifer, a representative of the terrestrial crust habitat. Deep groundwater of meteoric origin was collected from underground boreholes drilled into the Cretaceous Toki granite, central Japan. A large sulfur isotopic fractionation of 20-60 permil diagnostic to microbial sulfate reduction is associated with the investigated groundwater containing sulfate below 0.2 mM. In contrast, a small carbon isotopic fractionation ( 30 permil) is not indicative of methanogenesis. Our results demonstrate that the deep biosphere in the terrestrial crust is metabolically active and playing a crucial role in the formation of reducing groundwater even under low energy fluxes.
Tonegawa, Sho*; Kasahara, Shigeru*; Fukuda, Tatsuo; Sugimoto, Kunihisa*; Yasuda, Nobuhiro*; Tsuruhara, Yugo*; Watanabe, Daiki*; Mizukami, Yuta*; Haga, Yoshinori; Matsuda, Tatsuma*; et al.
Nature Communications (Internet), 5, p.4188_1 - 4188_7, 2014/06
Times Cited Count:52 Percentile:89.07(Multidisciplinary Sciences)Horikawa, Daiki*; Yamaguchi, Ayami*; Sakashita, Tetsuya; Tanaka, Daisuke*; Hamada, Nobuyuki*; Yukuhiro, Fumiko*; Kuwahara, Hirokazu*; Kunieda, Takekazu*; Watanabe, Masahiko*; Nakahara, Yuichi*; et al.
Astrobiology, 12(4), p.283 - 289, 2012/04
Times Cited Count:23 Percentile:68.76(Astronomy & Astrophysics)We examined the hatchability of hydrated and anhydrobiotic eggs of the tardigrade to hatch after ionizing irradiation (helium ions), extremely low and high temperatures, and high vacuum. Anhydrobiotic eggs (50% lethal dose; 1690 Gy) were substantially more radioresistant than hydrated ones (50% lethal dose; 509 Gy). Anhydrobiotic eggs also have a broader temperature resistance compared with hydrated ones. Over 70% of the anhydrobiotic eggs treated at high and low temperatures, but all of the hydrated eggs failed to hatch. After exposure to high vacuum conditions, the hatchability of the anhydrobiotic eggs was comparable to that of untreated control eggs.
Horikawa, Daiki*; Kunieda, Takekazu*; Abe, Wataru*; Watanabe, Masahiko*; Nakahara, Yuichi*; Yukuhiro, Fumiko*; Sakashita, Tetsuya; Hamada, Nobuyuki*; Wada, Seiichi*; Funayama, Tomoo; et al.
Astrobiology, 8(3), p.549 - 556, 2008/06
Times Cited Count:94 Percentile:90.99(Astronomy & Astrophysics)We report the successful rearing of the herbivorous tardigrade, , by supplying the green alga as food. The life span was 35 d, deposited eggs required 5.7 d to hatch, and animals began to deposit eggs 9 d after hatching. The reared individuals of this species had an anhydrobiotic capacity throughout their life cycle in egg, juvenile, and adult stages. Furthermore, the reared adults in an anhydrobiotic state were tolerant of temperatures of 90C and -196C and exposure to 99.8% acetonitrile or irradiation with 4000 Gy He ions. Based on their life history traits and tolerance to extreme stresses, might be a suitable model for astrobiological studies of multicellular organisms.
Nakahara, Yuichi*; Watanabe, Masahiko*; Kikawada, Takahiro*; Fujita, Akihiko*; Horikawa, Daiki*; Okuda, Takashi*; Sakashita, Tetsuya; Funayama, Tomoo; Hamada, Nobuyuki*; Wada, Seiichi*; et al.
JAEA-Review 2007-060, JAEA Takasaki Annual Report 2006, P. 113, 2008/03
We have shown that anhydrobiotic larvae of have higher tolerance against both high linear energy transfer (LET) radiation than hydrated larvae. We therefore examined effects of high-LET radiation on four kinds of larvae: (1) normal hydrated (intact) larva, (2) intermediates between the anhydrobiotic and normal hydrated state, (3) almost completely dehydrated (anhydrobiotic) larvae, and (4) immediately rehydrated larvae that are assumed to have a similar molecular profile to anhydrobiotic larvae. The intermediates and immediately rehydrated larvae survived longer after high-LET radiation than intact larvae, indicating that radiation tolerance could be enhanced even in hydrated larvae. Physiological changes toward anhydrobiosis, e.g. accumulation of protectants or increasing damage repair capacity, correlate with improved radiation tolerance in hydrated larvae.
Watanabe, Takehito*; Arakawa, Hiroyuki*; Kajimoto, Tsuyoshi*; Iwamoto, Yosuke; Satoh, Daiki; Kunieda, Satoshi; Noda, Shusaku*; Shigyo, Nobuhiro*; Ishibashi, Kenji*; Nakamura, Takashi*; et al.
Nuclear Instruments and Methods in Physics Research A, 587(1), p.20 - 28, 2008/03
Times Cited Count:1 Percentile:13.75(Instruments & Instrumentation)We have developed a phoswich detector for neutron spectrometry, which adopts a reversed configuration of slow- and fast-decay-time scintillators in its inner and surrounding outer regions, respectively, in the detection of recoil protons from a hydrogenous radiator. The phoswich detector consists of an inner slow, NaI(Tl) scintillator, and an outer fast, plastic scintillator. The response functions of the phoswich detector were measured for neutron energies ranging from 100 to 350 MeV. The experiment used the recoil-proton method and pulse-shape discrimination with the two-gate integration technique using a spallation neutron source at the WNR facility of the LANSCE. To evaluate the effectiveness of the phoswich configuration, full energy deposition fraction was calculated. The calculation confirmed that the phoswich detector with a reversed configuration is useful for neutron measurements.
Watanabe, Masahiko*; Nakahara, Yuichi*; Sakashita, Tetsuya; Kikawada, Takahiro*; Fujita, Akihiko*; Hamada, Nobuyuki*; Horikawa, Daiki*; Wada, Seiichi*; Kobayashi, Yasuhiko; Okuda, Takashi*
Journal of Insect Physiology, 53(6), p.573 - 579, 2007/06
Times Cited Count:20 Percentile:65.12(Entomology)We examined effects of high-LET radiation on 4 kinds of larvae: (1) normal hydrated (intact) larva, (2) intermediates between the anhydrobiotic and normal hydrated state, (3) almost completely dehydrated (anhydrobiotic) larvae, and (4) immediately-rehydrated larvae that are assumed to have a similar molecular profile to anhydrobiotic larvae. The intermediates and immediately-rehydrated larvae survived longer after high-LET radiation than intact larvae, indicating that radiation tolerance could be enhanced even in hydrated larvae. Physiological changes toward anhydrobiosis, e.g. accumulation of protectants or increasing damage repair capacity, correlate with improved radiation tolerance in hydrated larvae. In addition, almost complete desiccation further enhanced radiation tolerance, possibly in a different way from the hydrated larvae.
Horikawa, Daiki*; Sakashita, Tetsuya; Katagiri, Chihiro*; Watanabe, Masahiko*; Kikawada, Takahiro*; Nakahara, Yuichi*; Hamada, Nobuyuki*; Wada, Seiichi*; Funayama, Tomoo; Higashi, Seigo*; et al.
JAEA-Review 2006-042, JAEA Takasaki Annual Report 2005, P. 116, 2007/02
no abstracts in English
Horikawa, Daiki*; Sakashita, Tetsuya; Katagiri, Chihiro*; Watanabe, Masahiko*; Kikawada, Takahiro*; Nakahara, Yuichi*; Hamada, Nobuyuki*; Wada, Seiichi*; Funayama, Tomoo; Higashi, Seigo*; et al.
International Journal of Radiation Biology, 82(12), p.843 - 848, 2006/12
Times Cited Count:130 Percentile:99.14(Biology)no abstracts in English
Watanabe, Masahiko*; Sakashita, Tetsuya; Fujita, Akihiko*; Kikawada, Takahiro*; Nakahara, Yuichi*; Hamada, Nobuyuki*; Horikawa, Daiki*; Wada, Seiichi*; Funayama, Tomoo; Kobayashi, Yasuhiko; et al.
International Journal of Radiation Biology, 82(12), p.835 - 842, 2006/12
Times Cited Count:19 Percentile:77.5(Biology)The aim of this study is to characterize the tolerance to high-LET radiations of. Larval survival and subsequent metamorphoses were compared between anhydrobiotic (dry) and non-anhydrobiotic (wet) samples after exposure to 1 to 7000 Gy of three types of heavy ions with LET values ranging from 16.2 to 321 keV/m. At all LET values measured, dry larvae consistently showed greater radiation tolerance than hydrated larvae, due to the disaccharide trehalose in anhydrobiotic animals. Relative biological effectiveness (RBE) values based on the median inhibitory doses reached a maximum at 116 keV/m (C). Anhydrobiosis potentiates radiation tolerance in terms of larval survival, pupation and adult emergence of exposed to high-LET radiations. larvae might have more efficient DNA damage repair after radiation than other chironomid species.
Watanabe, Masahiko*; Sakashita, Tetsuya; Fujita, Akihiko*; Kikawada, Takahiro*; Horikawa, Daiki*; Nakahara, Yuichi*; Wada, Seiichi*; Funayama, Tomoo; Hamada, Nobuyuki*; Kobayashi, Yasuhiko; et al.
International Journal of Radiation Biology, 82(8), p.587 - 592, 2006/08
Times Cited Count:35 Percentile:90.02(Biology)The present study aims to evaluate effects of anhydrobiosis on radiation tolerance in an anhydrobiotic insect, Polypedilum vanderplanki. Larval survival (48 h), anhydrobiotic ability, metamorphosis and reproduction after exposure to 1 to 9000 Gy of -rays at the larval stage were comparedbetween anhydrobiotic (dry) and normal (wet) phases. Wet larvae were killed in a dose-dependent manner at doses higher than 2000 Gy, and all died within 8 h after 4000 Gy exposure. In contrast, dry larvae survived even 5000 Gy, and some of them still tolerated 7000 Gy and were alive at 48 h after rehydration. Moreover, greater radiotolerance of dry larva, compared to wet ones, was demonstrated interms of metamorphoses. However, anhydrobiosis did not protect against radiation damage in terms of producing viable offspring. These results indicate that anhydrobiosis enhances radiotolerance, resulting in increases of successful metamorphoses.
Horikawa, Daiki*; Sakashita, Tetsuya; Katagiri, Chihiro*; Watanabe, Masahiko*; Nakahara, Yuichi*; Okuda, Takashi*; Hamada, Nobuyuki*; Wada, Seiichi*; Funayama, Tomoo; Kobayashi, Yasuhiko
no journal, ,
no abstracts in English
Horikawa, Daiki*; Watanabe, Masahiko*; Nakahara, Yuichi*; Kikawada, Takahiro*; Okuda, Takashi*; Sakashita, Tetsuya; Funayama, Tomoo; Hamada, Nobuyuki*; Wada, Seiichi*; Kobayashi, Yasuhiko; et al.
no journal, ,
no abstracts in English
Horikawa, Daiki*; Sakashita, Tetsuya; Katagiri, Chihiro*; Watanabe, Masahiko*; Nakahara, Yuichi*; Kikawada, Takahiro*; Hamada, Nobuyuki*; Wada, Seiichi*; Funayama, Tomoo; Higashi, Seigo*; et al.
no journal, ,
no abstracts in English
Wadachi, Hiroki*; Kunieda, Takekazu*; Abe, Wataru*; Nakahara, Yuichi*; Watanabe, Masahiko*; Sakashita, Tetsuya; Hamada, Nobuyuki*; Kobayashi, Yasuhiko; Higashi, Seigo*; Okuda, Takashi*
no journal, ,
We collected some kinds of tardigrade to develop multi-cellular model oraganism for extremotolerant. Among four kinds of collected tardigrade, we found that a tardigrade at Sapporo-city feeded and could breed. The life-time of in an artificial culture condition is about 35 days and 5.7 days for hatching. During the whole life-time, one animal laids 8 eggs. In addition, it was observed that could enter an ametabolic dry state called anhydrobiosis in all stages of life-time. Furthermore, we observed a high surviving-rate even if exposed in various kinds of extreme environments.
Nakahara, Yuichi*; Watanabe, Masahiko*; Sakashita, Tetsuya; Hamada, Nobuyuki*; Gusev, O.*; Fujita, Akihiko*; Kikawada, Takahiro*; Horikawa, Daiki*; Kobayashi, Yasuhiko; Okuda, Takashi*
no journal, ,
The present study aims to evaluate effects of anhydrobiosis on radiation tolerance in an anhydrobiotic insect, . Wet larvae were killed in a dose-dependent manner at doses higher than 2000 Gy, and all died within 8 h after 4000 Gy exposure. However, anhydrobiosis did not protect against radiation damage in terms of producing viable offspring. These results indicate that anhydrobiosis enhances radiotolerance in larvae, but not in the delayed effects of development.
Horikawa, Daiki*; Kunieda, Takekazu*; Abe, Wataru*; Koshikawa, Shigeyuki*; Nakahara, Yuichi*; Watanabe, Masahiko*; Iwata, Kenichi*; Sakashita, Tetsuya; Hamada, Nobuyuki*; Higashi, Seigo*; et al.
no journal, ,
We report the first successful rearing of the herbivorous tardigrade, , by supplying a green alga as a food. The reared individuals of this species had an anhydrobiotic capacity throughout their life cycle, from eggs, to juveniles, and to adults. Reared adults, while in an anhydrobiotic state, were tolerant to temperatures -196C and 100C. Furthermore, they were shown to be tolerant to the exposure to 99.8% acetonitrile, 1 GPa of hydrostatic pressure, or 5000 Gy of He ion radiation. We will report the details of these results, along with the description of their life history. Due to the observed tolerance to such extreme environmental conditions, we propose R. varieornatus to be included as a suitable model for astrobiological studies of multicellular organisms.
Matsukawa, Yoshitaka*; Watanabe, Daiki*; Tsurekawa, Sadahiro*; Abad, N. M.*; Muta, Hiroaki*; Yoshida, Kenta*; Kasada, Ryuta*; Yamaguchi, Masatake; Kumano, Hideki*; Endo, Minako*
no journal, ,
It is now generally believed that when a light water reactor is operated for nearly 80 years, Ni-Si-Mn ternary intermetallic compounds such as the G phase and the phase precipitate in the pressure vessel steel, which contribute to irradiation embrittlement. We have started a basic study focusing on the relationship between these compounds and diffusion coefficients. In order to investigate the characteristics of interdiffusion at the precipitate/matrix interface of pressure vessel steels, bulk materials of the compounds were prepared by arc melting and bonded to bulk materials of pure iron to produce so-called diffusion pairs. In this report, we describe our findings for the G phase.