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Matsuya, Yusuke; McMahon, S. J.*; Butterworth, K. T.*; Naijo, Shingo*; Nara, Isshi*; Yachi, Yoshie*; Saga, Ryo*; Ishikawa, Masayori*; Sato, Tatsuhiko; Date, Hiroyuki*; et al.
Physics in Medicine & Biology, 66(7), p.075014_1 - 075014_11, 2021/04
Times Cited Count：6 Percentile：49.19(Engineering, Biomedical)Hypoxic cancer cells within solid tumours show radio-resistance, leading to malignant progression in fractionated radiotherapy. When prescribing dose to tumours under heterogeneous oxygen pressure with intensity-modulated radiation fields, intercellular signalling could have an impact on radiosensitivity between in-field and out-of-field cells. However, the impact of hypoxia on radio-sensitivity under modulated radiation intensity remains uncertain. In this study, we investigate the impact of hypoxia on in-field and out-of-field radio-sensitivities using two types of cancer cells. These in vitro measurements indicate that hypoxia apparently impacts out-of-field cells, although the OER values in out-of-field cells were smaller compared to those for in-field and uniformly irradiated cells. These decreased radio-sensitivities of out-of-field cells were shown as a consistent tendency for both DSB and cell death endpoints, suggesting that radiation-induced intercellular communication is of importance in treatment planning with intensity-modulated radiotherapy.
resonances in a boxOno, Akira*; Xu, J.*; Colonna, M.*; Danielewicz, P.*; Ko, C. M.*; Tsang, M. B.*; Wang, Y,-J.*; Wolter, H.*; Zhang, Y.-X.*; Chen, L.-W.*; et al.
Physical Review C, 100(4), p.044617_1 - 044617_35, 2019/10
Times Cited Count：71 Percentile：98.61(Physics, Nuclear)International comparison of heavy-ion induced reaction models were discussed in the international conference "Transport2017" held in April 2017. Owing to their importance for safety assessment of heavy-ion accelerators and dosimetry of astronauts, various models to simulate heavy-ion induced reaction models are developed. This study is intended to clarify the difference among them to pinpoint their problems. In the comparison study, 320 protons and neutrons were packed in a 20-fm-large cube to calculate the number and energies of collisions during the time evolution. The author contributed to this study by running calculation using JQMD (JAERI Quantum Molecular Dynamics). This study showed that time step in the calculation is one of the biggest causes of the discrepancies. For example, the calculation by JQMD comprises 1-fm/c time steps, each of which is composed of transport, scattering and decay phases. Therefore a sequence of scattering, and decay followed by another scattering in 1 fm/c cannot be considered. Moreover, in JQMD particles are labeled by sequential numbers and scattering reactions are simulated by the order. Therefore scattering between low ID numbers, that between high ID numbers and that between the first (low ID) pair is overlooked in JQMD. Above indications obtained in this study must be kept in our mind for future JQMD upgrades.
Zhang, Y.-X.*; Wang, Y,-J.*; Colonna, M.*; Danielewicz, P.*; Ono, Akira*; Tsang, M. B.*; Wolter, H.*; Xu, J.*; Chen, L.-W.*; Cozma, D.*; et al.
Physical Review C, 97(3), p.034625_1 - 034625_20, 2018/03
Times Cited Count：112 Percentile：99.01(Physics, Nuclear)International comparison of heavy-ion induced reaction models were discussed in the international conference "Transport2017" held in April 2017. Owing to their importance for safety assessment of heavy-ion accelerators and dosimetry of astronauts, various models to simulate heavy-ion induced reaction models are developed. This study is intended to clarify the difference among them to pinpoint their problems. In the comparison study, 320 protons and 320 neutrons were packed in a 20-fm-large cube to calculate the number of particle-particle collisions as well as the energies of collisions during the time evolution. In addition to the calculation, their algorithms were compared. The author contributed to this study by running calculation using JQMD (JAERI Quantum Molecular Dynamics). The results were compared with those calculated by the other 15 codes from over the world. Algorithm comparison showed that JQMD calculates collision probabilities from protons at first and collisions by neutrons are simulated later, which might be unreasonable. On the other hand, it was clarified that the calculation by JQMD agrees with those by the others. Despite the fact that some codes deviate from the average by a factor of 2, JQMD exhibited stable performance.
Okumura, Susumu; Arakawa, Kazuo; Fukuda, Mitsuhiro; Nakamura, Yoshiteru; Yokota, Wataru; Ishimoto, Takayuki*; Kurashima, Satoshi; Ishibori, Ikuo; Nara, Takayuki; Agematsu, Takashi; et al.
AIP Conference Proceedings 600, p.330 - 332, 2001/00
Frequent corrections of the magnetic field of the JAERI AVF cyclotron were required for keeping a beam current constant during long time operation. We observed correlation between the magnetic field and the temperature of the cyclotron magnet yoke by measuring the magnetic field with an NMR probe and the temperature with platinum resistance thermometers. The unstable phenomenon of a cyclotron beam was induced by temperature change in the magnet yoke caused mainly by thermal conduction from the main coil. To restrain the thermal conduction to the yoke, we have inserted temperature controlled copper plates between the yoke and the main coil. In addition, a temperature control system of the cooling water of the trim coils has been installed independent of the total cooling system for controlling the pole tip temperature. An optimum condition of the temperature control systems for stabilizing the magnetic field has been investigated.
Okumura, Susumu; Kurashima, Satoshi; Ishimoto, Takayuki*; Yokota, Wataru; Arakawa, Kazuo; Fukuda, Mitsuhiro; Nakamura, Yoshiteru; Ishibori, Ikuo; Nara, Takayuki; Agematsu, Takashi; et al.
Proceedings of 13th Symposium on Accelerator Science and Technology, p.283 - 285, 2001/00
no abstracts in English
Agematsu, Takashi; Arakawa, Kazuo; Okumura, Susumu; Nakamura, Yoshiteru; Yokota, Wataru; Nara, Takayuki; Fukuda, Mitsuhiro; Ishibori, Ikuo; ; Tachikawa, T.*
Proc. of the 9th Symp. on Accelerator Science and Technology, p.65 - 67, 1993/00
no abstracts in English
Yokota, Wataru; Nara, Takayuki; Arakawa, Kazuo; Nakamura, Yoshiteru; Fukuda, Mitsuhiro; Agematsu, Takashi; Okumura, Susumu; Ishibori, Ikuo; Tachikawa, T.*; ; et al.
Proceedings of 13th International Conference on Cyclotrons and Their Applications, p.336 - 339, 1993/00
no abstracts in English
Arakawa, Kazuo; Nakamura, Yoshiteru; Yokota, Wataru; Fukuda, Mitsuhiro; Nara, Takayuki; Agematsu, Takashi; Okumura, Susumu; Ishibori, Ikuo; ; Tanaka, Ryuichi; et al.
Proceedings of 13th International Conference on Cyclotrons and Their Applications, p.119 - 122, 1993/00
no abstracts in English
Yokota, Wataru; Fukuda, Mitsuhiro; Arakawa, Kazuo; Nakamura, Yoshiteru; Nara, Takayuki; Agematsu, Takashi; Okumura, Susumu; Ishibori, Ikuo; Tachikawa, T.*; ; et al.
Proceedings of 13th International Conference on Cyclotrons and Their Applications, p.581 - 584, 1993/00
no abstracts in English
Tachikawa, T.*; ; ; ; Nakamura, Yoshiteru; Yokota, Wataru; Fukuda, Mitsuhiro; Kamiya, Tomihiro; Agematsu, Takashi; Nara, Takayuki; et al.
Proceedings of the International Conference on Evolution in Beam Applications, p.270 - 274, 1992/00
no abstracts in English
Tanaka, Ryuichi; Arakawa, Kazuo; Yokota, Wataru; Nakamura, Yoshiteru; Kamiya, Tomihiro; Fukuda, Mitsuhiro; Agematsu, Takashi; Watanabe, H.; Akiyama, N.; Tanaka, S.; et al.
Proceedings of 12th International Conference on Cyclotrons and Their Applications (CYCLOTRONS 89), p.566 - 569, 1991/07
no abstracts in English
Arakawa, Kazuo; Nakamura, Yoshiteru; Yokota, Wataru; Fukuda, Mitsuhiro; Kamiya, Tomihiro; Nara, Takayuki; Agematsu, Takashi; Okumura, Susumu; Ishibori, Ikuo; Tanaka, Ryuichi; et al.
Proc. of the 8th Symp. on Accelerator Science and Technology, p.34 - 36, 1991/00
no abstracts in English
Yokota, Wataru; Ishibori, Ikuo; Okumura, Susumu; Agematsu, Takashi; Fukuda, Mitsuhiro; Nara, Takayuki; Kamiya, Tomihiro; Nakamura, Yoshiteru; Arakawa, Kazuo; Tachikawa, T.*; et al.
Proc. of the 8th Symp. on Accelerator Science and Technology, p.70 - 72, 1991/00
no abstracts in English
