The Possible interplanetary transfer of microbes; Assessing the viability of spp. under the ISS environmental conditions for performing exposure experiments of microbes in the Tanpopo mission

Kawaguchi, Yuko*; Yang, Y.*; Kawashiri, Narutoshi*; Shiraishi, Keisuke*; Takasu, Masako*; Narumi, Issey*; Sato, Katsuya; Hashimoto, Hirofumi*; Nakagawa, Kazumichi*; Tanigawa, Yoshiaki*; et al.

Origins of Life and Evolution of Biospheres, 43(4-5), p.411 - 428, 2013/10

https://doi.org/10.1007/s11084-013-9346-1

The Effect of temperature on the response of alanine dosimeters under low dose and long time irradiation

Nagao, Yuto; Seito, Hajime; Momoki, Yohei*; Kaneko, Hirohisa; Nakagawa, Kazumichi*; Kojima, Takuji

Radioisotopes, 61(4), p.173 - 177, 2012/04

https://doi.org/10.3769/radioisotopes.61.173

Applications of alanine dosimeter are widen to dosimetry in space environment and so on. The effect of temperature during and after irradiation between 20C and 80C on the dose response of alanine dosimeters was investigated under low dose of about 10 - 20 Gy and long time of about 100 hours irradiations. When a stable component of the dose response under high irradiation temperature is estimated on the basis of the effect of storage temperature after irradiation taking into account the known irradiation temperature coefficient, dose evaluation using alanine dosimeter should be more accurate even suffering from combined temperature effects during and after irradiation.

Soft X-ray natural circular dichroism spectra of amino acids measured by a transmission method

Izumi, Yudai*; Momoki, Yohei*; Tanigawa, Yoshiaki*; Tanaka, Masahito*; Agui, Akane; Nakagawa, Kazumichi*

no journal, , 

no abstracts in English

Nitrogen K-edge soft X-ray natural circular dichroism of histidine thin film

Izumi, Yudai; Tanaka, Masahito*; Tanigawa, Yoshiaki*; Momoki, Yohei*; Iwai, Miki*; Takenaka, Shun*; Ishiyama, Kimihiro*; Kuroki, Misa*; Muro, Takayuki*; Nakagawa, Kazumichi*

no journal, , 

It is unclear whether natural circular dichroism (NCD) originating from core-absorption of atoms located at various sites, as well as next to the asymmetric carbon, in the molecules can be observed selectively. In this study, we measured NCD spectra of an amino acid, histidine (His) which has three nitrogen atoms, thin film in the nitrogen K-edge energy region and confirmed whether we can pick up the NCD signals originating from each nitrogen atom throughout the molecules. NCD peaks assigned to the 1s of the nitrogen atoms in imidazole ring and the 1s transition of the nitrogen atoms in imidazole ring and amino group. Imidazole ring and amino group are positioned at the side chain distant from and next to the asymmetric carbon, respectively. This result suggests that NCD spectroscopy in the soft X-ray region can selectively pick up the information on local structure around specific atoms, regardless of the position of atoms in molecules.

Investigation of the survivability of spp. under space

Kawaguchi, Yuko*; Yang, Y.*; Murano, Yuka*; Harada, Miyu*; Kawashiri, Narutoshi*; Shiraishi, Keisuke*; Takasu, Masako*; Narumi, Issey*; Sato, Katsuya; Hashimoto, Hirofumi*; et al.

no journal, , 

no abstracts in English