Changes in molecular conformation and electronic structure of DNA under C ions based on first-principles calculations

Sekikawa, Takuya; Matsuya, Yusuke; Hwang, B.*; Ishizaka, Masato*; Kawai, Hiroyuki*; Ono, Yoshiaki*; Sato, Tatsuhiko; Kai, Takeshi

Nuclear Instruments and Methods in Physics Research B, 548, p.165231_1 - 165231_6, 2024/03

https://doi.org/10.1016/j.nimb.2023.165231

One of the main causes of radiation effects on the human body is thought to be damage to DNA, which carries genetic information. However, it is not fully understood what kind of molecular structural changes DNA undergoes upon radiation damage. Since it has been reported that various types of DNA damage are formed when DNA is irradiated, our group has investigated the relationship between DNA damage and various patterns of radiation-induced ionization induced by radiation. Although we have so far analyzed DNA damage in a simple system using a rigid body model of DNA, more detailed calculations are required to analyze the molecular structural changes in DNA, which are considered to be important in considering the effects on the human body. In this study, we attempted to clarify the molecular conformational changes of DNA using OpenMX, a first-principles calculation software that can discuss electronic states based on molecular structures. Specifically, we calculated the most stable structure, band dispersion, and wave function of DNA under the assumption that one and two electrons are ionized by various radiation. In the presentation, we will discuss the relationship between the energy dependence of each incident radiation type and the molecular conformational change of DNA. In addition, the radiation-induced changes in the basic physical properties of DNA (corresponding to the initial stage of DNA damage) will be discussed from the viewpoints of both radiation physics and solid state physics.

R&D of digital technology on inverse estimation of radioactive source distributions and related source countermeasures; R&D status of digital platform including 3D-ADRES-indoor

Machida, Masahiko; Yamada, Susumu; Kim, M.; Okumura, Masahiko; Miyamura, Hiroko; Shikaze, Yoshiaki; Sato, Tomoki*; Numata, Yoshiaki*; Tobita, Yasuhiro*; Yamaguchi, Takashi; et al.

RIST News, (69), p.2 - 18, 2023/09

https://www.rist.or.jp/rnews/69/69s2.pdf

The contamination of radioactive materials leaked from the reactor has resulted in numerous hot spots in the Fukushima Daiichi Nuclear Power Station (1F) building, posing obstacles to its decommissioning. In order to solve this problem, JAEA has conducted research and development of the digital technique for inverse estimation of radiation source distribution and countermeasures against the estimated source in virtual space for two years from 2021 based on the subsidy program "Project of Decommissioning and Contaminated Water Management" performed by the funds from the Ministry of Economy, Trade and Industry. In this article, we introduce the results of the project and the plan of the renewal project started in April 2023. For the former project, we report the derivative method for LASSO method considering the complex structure inside the building and the character of the source and show the result of the inverse estimation using the method in the real reactor building. Moreover, we explain the platform software "3D-ADRES-Indoor" which integrates these achievements. Finally, we introduce the plan of the latter project.

The Energy-resolved neutron imaging system, RADEN

Shinohara, Takenao; Kai, Tetsuya; Oikawa, Kenichi; Nakatani, Takeshi; Segawa, Mariko; Hiroi, Kosuke; Su, Y. H.; Oi, Motoki; Harada, Masahide; Iikura, Hiroshi; et al.

Review of Scientific Instruments, 91(4), p.043302_1 - 043302_20, 2020/04

https://doi.org/10.1063/1.5136034

Characteristics of the 2012 model lithium-6 time-analyzer neutron detector (LiTA12) system as a high efficiency detector for resonance absorption imaging

Kai, Tetsuya; Sato, Setsuo*; Hiroi, Kosuke; Su, Y. H.; Segawa, Mariko; Parker, J. D.*; Matsumoto, Yoshihiro*; Hayashida, Hirotoshi*; Shinohara, Takenao; Oikawa, Kenichi; et al.

Physica B; Condensed Matter, 551, p.496 - 500, 2018/12

https://doi.org/10.1016/j.physb.2017.11.086

Inverse pole figure mapping of bulk crystalline grains in a polycrystalline steel plate by pulsed neutron Bragg-dip transmission imaging

Sato, Hirotaka*; Shiota, Yoshinori*; Morooka, Satoshi; Todaka, Yoshikazu*; Adachi, Nozomu*; Sadamatsu, Sunao*; Oikawa, Kenichi; Harada, Masahide; Zhang, S.*; Su, Y. H.; et al.

Journal of Applied Crystallography, 50(6), p.1601 - 1610, 2017/12

https://doi.org/10.1107/S1600576717012900

Study on engineering technologies in the Mizunami Underground Research Laboratory (FY 2015); Development of design and construction planning and countermeasure technologies (Contract research)

Toguri, Satohito*; Kobayashi, Shinji*; Tsuji, Masakuni*; Yahagi, Ryoji*; Yamada, Toshiko*; Matsui, Hiroya; Sato, Toshinori; Mikake, Shinichiro; Aoyagi, Yoshiaki

JAEA-Technology 2017-005, 43 Pages, 2017/03

JAEA-Technology-2017-005.pdf:4.4MB

The study on engineering technology in the Mizunami Underground Research Laboratory (MIU) project roughly consists of (1) development of design and construction planning technologies, (2) development of construction technology, (3) development of countermeasure technology, (4) development of technology for security, and (5) development of technologies regarding restoration and mitigating of the excavation effect. In FY2015, as a part of the important issues on the research program, water-tight grouting method has been developed. Grouting methods utilized in the MIU were evaluated and the post-excavation grouting at the -500m Access/Research Gallery-South was planned based on these evaluation results. Also, technology development from the viewpoint of geological disposal was summarized, and information on the alternative method to the grouting method was collected and organized.

A Comparative study of the crystallite size and the dislocation density of bent steel plates using Bragg-edge transmission imaging, TOF neutron diffraction and EBSD

Oikawa, Kenichi; Su, Y. H.; Tomota, Yo*; Kawasaki, Takuro; Shinohara, Takenao; Kai, Tetsuya; Hiroi, Kosuke; Zhang, S.*; Parker, J. D.*; Sato, Hirotaka*; et al.

Physics Procedia, 88, p.34 - 41, 2017/00

https://doi.org/10.1016/j.phpro.2017.06.004

Time of flight Bragg edge transmission (BET) imaging was adopted to the plastically bent plates of a ferritic steel and a duplex stainless steel, and the obtained results were validated using neutron diffraction method and electron backscatter diffraction (EBSD) observations. The BET imaging results of texture distribution and phase volume fractions showed good agreements with those obtained by neutron diffraction and EBSD. The crystallite size evaluation using extinction correction was succeeded by the RITS code where Sabine's primary extinction function was applied, however, the crystallite size was not obtained by the Rietveld refinement where the same function was used for the evaluation. In this study, we comparatively reinvestigate the crystallite size and the dislocation density of the plastically bent steel plates by the use of Pawley analysis on the diffraction data and grain analysis on EBSD data.

Time-of-flight neutron Bragg-edge transmission imaging of microstructures in bent steel plates

Su, Y. H.; Oikawa, Kenichi; Harjo, S.; Shinohara, Takenao; Kai, Tetsuya; Harada, Masahide; Hiroi, Kosuke; Zhang, S.*; Parker, J. D.*; Sato, Hirotaka*; et al.

Materials Science & Engineering A, 675, p.19 - 31, 2016/10

https://doi.org/10.1016/j.msea.2016.08.037

Study on engineering technologies in the Mizunami Underground Research Laboratory (FY 2014); Development of recovery and mitigation technology on excavation damage (Contract research)

Fukaya, Masaaki*; Hata, Koji*; Akiyoshi, Kenji*; Sato, Shin*; Takeda, Nobufumi*; Miura, Norihiko*; Uyama, Masao*; Kaneda, Tsutomu*; Ueda, Tadashi*; Hara, Akira*; et al.

JAEA-Technology 2016-002, 195 Pages, 2016/03

JAEA-Technology-2016-002.pdf:46.3MB
JAEA-Technology-2016-002-appendix(CD-ROM).zip:16.11MB

The researches on examination of the plug applied to the future reflood test was conducted as a part of (5) development of technologies for restoration and/on reduction of the excavation damage relating to the engineering technology in the MIU (2014), specifically focused on (1) plug examination (e.g. functions, structure and material) and the quality control methods and (2) analytical evaluation of rock mass behavior around the plug through the reflood test. As the result, specifications of the plug were determined. These specifications should be able to meet requirements for the safety structure and surrounding rock mass against predicted maximum water pressure, temperature stress and seismic force, and for controlling the groundwater inflow, ensuring the access into the reflood gallery and the penetration performance of measurement cable. Also preliminary knowledge regarding the rock mass behavior around the plug after flooding the reflood gallery by installed plug was obtained.

Final design of the energy-resolved neutron imaging system "RADEN" at J-PARC

Shinohara, Takenao; Kai, Tetsuya; Oikawa, Kenichi; Segawa, Mariko; Harada, Masahide; Nakatani, Takeshi; Oi, Motoki; Aizawa, Kazuya; Sato, Hirotaka*; Kamiyama, Takashi*; et al.

Journal of Physics; Conference Series, 746, p.012007_1 - 012007_6, 2016/00

https://doi.org/10.1088/1742-6596/746/1/012007

no abstracts in English