Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Sato, Tatsuhiko; Furuta, Takuya; Sasaki, Hidetaka*; Watabe, Tadashi*
EJNMMI Physics (Internet), 12, p.28_1 - 28_16, 2025/03
Times Cited Count：0Shimizu, Shota*; Sato, Tatsuhiko; Endo, Akira; 5 of others*
Radiation Research, 203(3), p.155 - 162, 2025/03
Times Cited Count：0 Percentile：0.00(Biology)Schaar, K.*; Spiegl, T.*; Sato, Tatsuhiko; Langematz, U.*
Journal of Environmental Radioactivity, 282, p.107592_1 - 107592_14, 2025/02
Times Cited Count：0 Percentile：0.00(Environmental Sciences)Ulanowski, A.*; Sato, Tatsuhiko; Petoussi-Henss, N.*; Balonov, M.*
Radiation and Environmental Biophysics, 11 Pages, 2025/02
Times Cited Count：1 Percentile：0.00(Biology)Sato, Tatsuhiko; Hashimoto, Shintaro; M
rquez Damin, J. I.*; Niita, Koji*
Nuclear Instruments and Methods in Physics Research B, 557, p.165535_1 - 165535_8, 2024/12
Times Cited Count：0 Percentile：0.00(Instruments & Instrumentation)Ogawa, Tatsuhiko; Hirata, Yuho; Matsuya, Yusuke; Kai, Takeshi; Sato, Tatsuhiko; Iwamoto, Yosuke; Hashimoto, Shintaro; Furuta, Takuya; Abe, Shinichiro; Matsuda, Norihiro; et al.
EPJ Nuclear Sciences & Technologies (Internet), 10, p.13_1 - 13_8, 2024/11
The latest updates on PHITS, a versatile radiation transport code, focusing specifically on track-structure models are presented. Track structure calculations are methods used to simulate the movement of charged particles while explicitly considering each atomic reaction. Initially developed for radiation biology, these calculation methods aimed to analyze the radiation-induced damage to DNA and chromosomes. Several track-structure calculation models, including PHITS-ETS, PHITS-ETS for Si, PHITS-KURBUC, ETSART, and ITSART, have been developed and implemented to PHITS. These models allow users to study the behavior of various particles at the nano-scale across a wide range of materials. Furthermore, potential applications of track-structure calculations have also been proposed so far. This collection of track-structure calculation models, which encompasses diverse conditions, opens up new avenues for research in the field of radiation effects.
Matsuya, Yusuke; Kai, Takeshi; Sato, Tatsuhiko
Shototsu, 21(3), p.R008_1 - R008_8, 2024/11
Particle and Heavy Ion Transport code System PHITS is a Monte Carlo code that enables the simulation of the behavior of radiation using a computer. Since 2018, a track-structure mode has been developed that allows the simulation of each atomic interaction in liquid water, which is a main component of living organisms. This development has made it possible to perform high-spatial resolution radiation track-structure analysis on the DNA scale. Meanwhile, based on the spatial information of atomic interactions calculated in the track-structure mode, we have also succeeded in developing an analysis code that enables the estimate of the various types of DNA damage yields efficiently and with high accuracy. In this review, we introduce an overview of the track-structure mode and DNA damage estimation model implemented in the latest version of PHITS, and show examples of applications of PHITS in the field of life sciences.
Parisi, A.*; Furutani, K. M.*; Sato, Tatsuhiko; Beltran, C. J.*
Medical Physics, 51(10), p.7589 - 7605, 2024/10
Times Cited Count：1 Percentile：57.45(Radiology, Nuclear Medicine & Medical Imaging)In this study, we have developed an approximate MKM (microdosimetric kinetic model) based on LET (dose-averaged linear energy transfer) to address the challenges of biological relative effectiveness (RBE) models for proton therapy. This is an attempt to apply the mechanism-based approach used in carbon ion therapy to proton beams. This LET-based MKM establishes a correlation between dose-averaged LET and microbiological indices and successfully models survival rates for multiple cell lines. This has resulted in a mathematical description of RBE based on physical quantities that can be readily used in proton therapy planning systems.
H to 
UParisi, A.*; Furutani, K. M.*; Sato, Tatsuhiko; Beltran, C. J.*
Quantum Beam Science (Internet), 8(3), p.18_1 - 18_16, 2024/09
Sato, Tatsuhiko; Matsuya, Yusuke; Hamada, Nobuyuki*
Journal of Radiation Research (Internet), 65(4), p.500 - 506, 2024/07
Times Cited Count：2 Percentile：78.29(Biology)We therefore evaluated the mean and uncertainty of relative biological effectiveness (RBE) for diseases of the circulatory system (DCS) by applying a microdosimetric kinetic model specialized for RBE estimation of tissue reactions. For this purpose, we analyzed several RBE data for DCS determined by past animal experiments and evaluated the radius of the subnuclear domain best fit to each experiment as a single free parameter included in the model. Our analysis suggested that RBE for DCS tends to be lower than that for skin reactions, and their difference was borderline significant due to large variances of the evaluated parameters. These findings will help determine RBE by ICRP for preventing tissue reactions.
Matsuya, Yusuke; Sato, Tatsuhiko; Kusumoto, Tamon*; Yachi, Yoshie*; Seino, Ryosuke*; Miwa, Misako*; Ishikawa, Masayori*; Matsuyama, Shigeo*; Fukunaga, Hisanori*
Scientific Reports (Internet), 14, p.16696_1 - 16696_14, 2024/07
Times Cited Count：3 Percentile：78.29(Multidisciplinary Sciences)Boron neutron capture therapy (BNCT) is a unique radiotherapy to selectively eradicate tumor cells using boron compounds (e.g., 4-borono-L-phenylalanine [BPA]) that are heterogeneously taken up at the cellular level. However, the impacts of tempo-spatial heterogenicity on cell killing remain unclear. With the technical combination of radiation track detector, cell cycle analysis, and biophysical simulations, we demonstrated the cell cycle-dependent heterogenicity of BPA uptake and following biological impacts of 
B(n, 
)
Li reactions in HeLa cells expressing Fluorescent Ubiquitination-based Cell Cycle Indicators (FUCCI), as well as its modification effects of polyvinyl alcohol (PVA). As a result, we revealed that the intracellular BPA concentration in the S/G2/M phase was higher than that in the G1/S phase and that PVA modified the cell cycle dependence. Further, these findings lead to the development of the first BPA-PVA-based model for predicting BNCT treatment effects. These outcomes may contribute to more precision of therapeutic efficacy, when BNCT is combined with PVA and/or cell cycle-specific anticancer agents.
Be for the detectability of solar proton eventsSchaar, K.*; Spiegl, T.*; Langematz, U.*; Sato, Tatsuhiko; Mekhaldi, F.*; Kunze, M.*; Miyake, Fusa*; Yoden, Shigeo*
Journal of Geophysical Research; Atmospheres, 129(11), p.e2023JD040463_1 - e2023JD040463_28, 2024/06
Times Cited Count：1 Percentile：46.64(Meteorology & Atmospheric Sciences)Ishikawa, Akihisa; Koba, Yusuke*; Furuta, Takuya; Chang, W.*; Yonai, Shunsuke*; Matsumoto, Shinnosuke*; Hashimoto, Shintaro; Hirai, Yuta*; Sato, Tatsuhiko
Radiological Physics and Technology, 17(2), p.553 - 560, 2024/06
Be and 
Al under direct muon-induced spallation in granite quartz and its implications for past high-energy cosmic ray fluxesSakurai, Hirohisa*; Kurebayashi, Yutaka*; Suzuki, Soichiro*; Horiuchi, Kazuho*; Takahashi, Yui*; Doshita, Norihiro*; Kikuchi, Satoshi*; Tokanai, Fuyuki*; Iwata, Naoyoshi*; Tajima, Yasushi*; et al.
Physical Review D, 109(10), p.102005_1 - 102005_18, 2024/05
Times Cited Count：0 Percentile：0.00(Astronomy & Astrophysics)Secular variations of galactic cosmic rays (GCRs) are inseparably associated with the galactic activities and should reflect the environments of the local galactic magnetic field, interstellar clouds, and nearby supernova remnants. The high-energy muons produced in the atmosphere by high-energy GCRs can penetrate deep underground and generate radioisotopes in the rock. As long lived radionuclides such as Be and Al have been accumulating in these rocks, concentrations of Be and Al can be used to estimate the long-term variations in high-energy muon yields, corresponding to those in the high-energy GCRs over a few million years. This study measured the production cross sections for muon induced Be and Al by irradiating positive muons with the momentum of 160 GeV/c on the synthetic silica plates and the granite core at the COMPASS experiment line in CERN SPS. In addition, it the contributions of the direct muon spallation reaction and the nuclear reactions by muon-induced particles on the production of long lived radionuclides in the rocks were clarified.
Sato, Tatsuhiko; Kubo, Yuki*
Purazuma, Kaku Yugo Gakkai-Shi, 100(5), p.218 - 223, 2024/05
One of the space weather hazards is the sudden occurrence of cosmic radiation exposure due to high-energy protons associated with massive solar flares. This paper focuses on cosmic radiation exposure for airline crew members, explaining the mechanisms and current regulations. Additionally, it introduces an overview of the recently developed Aircraft Radiation Exposure Warning System (WASAVIES) in Japan.
Matsuya, Yusuke; Sato, Tatsuhiko; Yachi, Yoshie*; Date, Hiroyuki*; Hamada, Nobuyuki*
Scientific Reports (Internet), 14, p.12160_1 - 12160_14, 2024/05
Times Cited Count：2 Percentile：78.29(Multidisciplinary Sciences)Understand mechanisms of radiation cataracts that are of concern in the field of radiation protection and radiation therapy. However, biological effects in HLEC following protracted exposure have not yet fully been explored. Here, we investigated the temporal kinetics of DNA double-strand breaks (DSBs) and cell survival of HLEC after exposure to photon beams at various dose rates, compared to those of human lung fibroblasts (WI-38). In parallel, we quantified the recovery for DSB and cell survival using a biophysical model. The study revealed that HLEC cells have a lower repair rate than WI-38 cells. There is no significant impact of dose rate on cell survival in both cell lines in the dose-rate range of 0.033-1.82 Gy/min. On the other hand, the experimental residual DSBs showed inverse dose rate effects (IDREs) compared to the model prediction, highlighting the importance of the IDREs in evaluating radiation effects on the ocular lens.
Sato, Tatsuhiko
Nihon Genshiryoku Gakkai-Shi ATOMO
, 66(3), p.143 - 145, 2024/03
DNA damage calculation using the track-structure mode of PHITS will be summarized in this report.
C ions based on first-principles calculationsSekikawa, 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
Times Cited Count：1 Percentile：63.95(Instruments & Instrumentation)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
hm, W.*; Ban, Nobuhiko*; Chen, J.*; Li, C.*; Dobynde, M.*; Durante, M.*; El-Jaby, S.*; Komiyama, Tatsuto*; Ozasa, Kotaro*; Sato, Tatsuhiko; et al.
Journal of Medical Physics - Zeitschrift fr medizinische Physik -, 34(1), p.4 - 13, 2024/02
The International Commission on Radiological Protection (ICRP) provides independent recommendations on radiological protection for the public benefit. For more than 90 years, the ICRP System of Radiological Protection has been guiding the development and implementation of national and international standards and regulations on radiological protection. In 2019, ICRP established Task Group (TG) 115 to address a broader range of topics related to dose and risk assessment for radiological protection of astronauts. This paper gives an overview of the System of Radiological Protection and a brief summary of ICRP's work on radiological protection of astronauts.
