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Journal Articles

Present status of JAEA-Tokai tandem accelerator and booster

Matsuda, Makoto; Osa, Akihiko; Ishizaki, Nobuhiro; Tayama, Hidekazu; Nakanoya, Takamitsu; Kabumoto, Hiroshi; Nakamura, Masahiko; Kutsukake, Kenichi; Otokawa, Yoshinori; Asozu, Takuhiro

Proceedings of 13th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.1413 - 1417, 2016/11

The tandem accelerator was operated over a total of 140 days and delivered 22 different ions to the experiments in the fields of nuclear physics, nuclear chemistry, atomic physics, solid state physics and radiation effects in material. Maximum accelerating voltage is keeping up 18 MV and there was used for ten days on this voltage. However, electric discharge was occurred frequently in December and accelerating voltage fell to 12 MV. The damaged acceleration tubes were replaced with the spare tube at the regular maintenance period in March. The superconducting booster was not operated. This paper describes the operational status of the accelerators and the major technical developments.

JAEA Reports

Study on small-sized tailless beam formation using multipole magnetic field (Joint research)

Yokota, Wataru; Yuri, Yosuke; Watanabe, Shinichi*; Oshiro, Yukimitsu*; Kubono, Shigeru*

JAEA-Technology 2016-005, 21 Pages, 2016/03

JAEA-Technology-2016-005.pdf:2.24MB

The Center of Nuclear Science (CNS) of Tokyo University conducts the research on nuclear physics using CNS Radio-Isotope Beam Separator (CRIB) installed at the RIKEN AVF cyclotron. Takasaki Advanced Radiation Research Institute, JAEA has an AVF cyclotron of similar scale and is developing a technology to form a large-area uniform beam by an octupole magnetic field for the research on materials science. They carried out an R&D to increase the cyclotron beam intensity at a target under joint research. The nonlinear beam optics was designed to form a usual cyclotron beam having a large transverse tail into a small-sized tailless distribution so that the beam passes the gas target orifice (6 mm in diameter) of CRIB without a loss. As a result of particle tracking simulations based on the measured beam emittance, it has been found that an octupole magnetic field is effective in tail-folding and a 10-mm-diameter beam can be formed with two octupole magnets added in the present beam line. It has been also found that additional magnets need to be installed and the beam emittance should be reduced for the objective beam size of 6 mm. Moreover, the objective may be attained if the beam path length and configuration of the magnetic lens system are freely chosen.

Journal Articles

The Role of nitric oxide in radiation-induced bystander cell-killing effect

Yokota, Yuichiro; Funayama, Tomoo; Ikeda, Hiroko; Sakashita, Tetsuya; Suzuki, Michiyo; Kobayashi, Yasuhiko

JAEA-Review 2015-022, JAEA Takasaki Annual Report 2014, P. 67, 2016/02

The role of nitric oxide (NO) in bystander effect was investigated. Human fibroblasts were irradiated with $$gamma$$-rays (LET: 0.2 keV/$$mu$$m) or carbon-ion beam (108 keV/$$mu$$m), and then, co-cultured with the non-irradiated cells. After 24 h culture, the survival rates of non-irradiated cells and the concentrations of nitrate, an oxide of NO, in the medium were measured. The survival rates of non-irradiated cells decreased in dose-dependent and radiation quality-independent manners. Negative relationships between survival rates and nitrite concentrations existed, indicating the amounts of produced NO are an important determinant of bystander effects. Next, a reagent producing two molecules of NO in a half-life of 100 min was added in the culture medium. After incubation of 24 h the survival rates of treated cells did not decrease, suggesting NO produced intracellularly has an important role to lead the bystander effect but is not the signal molecule for intercellular communication.

Journal Articles

The Bystander cell-killing effect mediated by nitric oxide in normal human fibroblasts varies with irradiation dose but not with radiation quality

Yokota, Yuichiro; Funayama, Tomoo; Muto, Yasuko*; Ikeda, Hiroko; Kobayashi, Yasuhiko

International Journal of Radiation Biology, 91(5), p.383 - 388, 2015/05

 Times Cited Count:5 Percentile:34.97(Biology)

We investigated the dependence of the bystander cell-killing effect on radiation dose and quality, and related molecular mechanisms. Human fibroblasts were irradiated with $$gamma$$-rays or carbon ions and co-cultured with non-irradiated cells. Survival rates of non-irradiated cells decreased and nitrite concentrations in culture medium increased with increasing doses. Their dose responses were similar between $$gamma$$-rays and carbon ions. Treatment of the specific nitric oxide (NO) radical scavenger prevented reductions in survival rates of non-irradiated cells. Negative relationships were observed between survival rates and nitrite concentrations. From these results, it was concluded that the bystander cell-killing effect mediated by NO radicals in human fibroblasts depends on irradiation doses, but not on radiation quality. NO radical production appears to be an important determinant of $$gamma$$-ray- and carbon-ion-induced bystander effects.

Journal Articles

Analysis of bystander effect induced by cell membrane response in glioma cells

Wada, Seiichi*; Ando, Tatsuhiko*; Watanabe, Aya*; Kakizaki, Takehiko*; Natsuhori, Masahiro*; Funayama, Tomoo; Sakashita, Tetsuya; Yokota, Yuichiro; Kobayashi, Yasuhiko

JAEA-Review 2014-050, JAEA Takasaki Annual Report 2013, P. 79, 2015/03

So far, we clarified that X-ray irradiation induced cell killing by bystander effect mediated-secreted factor. This phenomenon was related with sphingomyelinase (SMase). In this study we analyzed mechanism of secreted SMase from irradiated cells after irradiation. SMase was detected in the culture medium after irradiation by SDS-PAGE. Then, SMase was detected in the exosome of culture medium, but not out of exosome after irradiation. This result indicates that SMase was secreted as exosome from the irradiated cells.

Journal Articles

Effect of heavy ion irradiation to the silkworm eggs at before fertilization and at nuclear cleavage stage

Ueda, Daisuke*; Shirai, Koji*; Funayama, Tomoo; Sakashita, Tetsuya; Yokota, Yuichiro; Kobayashi, Yasuhiko

JAEA-Review 2014-050, JAEA Takasaki Annual Report 2013, P. 84, 2015/03

In this study, we investigated the effects of irradiation to the silkworm eggs at various developmental stages. First, we tried the irradiation to the unfertilized eggs (at 1.5 hour after oviposition). At this stage, the female pronucleus and the sperm nucleus are observed in the eggs, but not fertilized. After irradiation, the irradiated eggs stopped the development after fertilization. About 2 hours after, the egg restarted the nuclear cleavage. This result indicates the DNA damage on pronuleus cannot prevent the fertilization. We also investigated the effects of irradiation to the egg at the nuclear cleavage stage (at 6 hour after oviposition). The egg also stopped the development after irradiation, but the duration time of the developmental arrest was almost two times longer (about 4 hours) than that of the egg irradiated at fertilization.

Journal Articles

LET dependency of human normal dermal cells survival in carbon ion irradiation

Yoshida, Yukari*; Mizohata, Kensuke*; Matsumura, Akihiko*; Isono, Mayu*; Yako, Tomoko*; Nakano, Takashi*; Funayama, Tomoo; Kobayashi, Yasuhiko; Kanai, Tatsuaki*

JAEA-Review 2014-050, JAEA Takasaki Annual Report 2013, P. 81, 2015/03

In the clinical application of carbon-ion (C-ion) radiation therapy in Japan, different RBE values of carbons have been used for clinical and biological endpoints. The biological RBE (bRBE) was estimated by a method that is based on the linear-quadratic (LQ) model, and was defined ${it in vitro}$ at the 10% surviving fraction of human salivary gland (HSG) tumor cells. However, many of biological parameters, that is, type of tissues, different sort of cells, oxygenation levels, and all, could affect radiosensitivity. Thus, normal human dermal fibroblasts (NHDF) cells were exposed to C-ion beams at Gunma University (10-80 keV/micrometer) and TIARA (108 and 158 keV/micrometer). The surviving fractions were analyzed with colony formation assays. The experimental RBE (eRBE) values were estimated from the radiation dose survival curve fitted by LQ model, and defined ${it in vitro}$.

Journal Articles

NHEJ repair rather than HR repair is the primary function to target to enhance radiosensitization at high LET values

Takahashi, Akihisa*; Kubo, Makoto*; Igarashi, Chie*; Yoshida, Yukari*; Funayama, Tomoo; Kobayashi, Yasuhiko; Nakano, Takashi*

JAEA-Review 2014-050, JAEA Takasaki Annual Report 2013, P. 82, 2015/03

DNA double-strand breaks (DSBs) induced by ionizing radiation pose a major threat to cell survival. The cell can respond to the presence of DSBs, through two major repair pathways: Homologous recombination (HR) and non-homologous end-joining (NHEJ). Higher levels of cell death are induced by high-LET radiation when compared to low-LET radiation, even at the same doses because of less effective or more inefficient DNA repair. In this study, we examine the effects of radiation with different LET values on DNA DSB repair and radiosensitivity. Wild-type cells and HR deficient (but NHEJ proficient) cells exhibited the high RBE values at LET values of 108 keV/$$mu$$ m. The RBE value for each cell type decreased with increasing LET values over 200 keV/$$mu$$m. Although NHEJ proficient cells had an almost constant SER value, NHEJ deficient cells showed a high SER value when compared to NHEJ proficient cells, even with increasing LET values.

Journal Articles

Increase in cell motility by carbon ion irradiation via the Rho signaling pathway and its inhibition by the ROCK inhibitor Y-27632 in lung adenocarcinoma A549 cells

Murata, Kazutoshi*; Noda, Shinei*; Oike, Takahiro*; Takahashi, Akihisa*; Yoshida, Yukari*; Suzuki, Yoshiyuki*; Ono, Tatsuya*; Funayama, Tomoo; Kobayashi, Yasuhiko; Takahashi, Takeo*; et al.

Journal of Radiation Research, 55(4), p.658 - 664, 2014/07

 Times Cited Count:9 Percentile:39.32(Biology)

The effect of carbon ion irradiation on cell motility through the Rho signaling pathway in the human lung adenocarcinoma cell line A549 was studied. At 48 h after irradiation, the cell motility of A549 cells became significantly greater, and the formation of protrusions significantly increased in cells irradiated with carbon ion. The observed increase in cell motility due to carbon ion irradiation was similar to that observed due to X-ray irradiation. Western-blot analysis showed that carbon ion irradiation increased P-MLC2-S19 expression compared with in unirradiated controls, while total MLC2 expression was unchanged. Exposure to a non-toxic concentration of Y-27632, a specific inhibitor of ROCK, reduced the expression of P-MLC2-S19 after C-ion irradiation, resulting in a significant reduction in migration. These data suggest that carbon irradiation increases cell motility in A549 cells via the Rho signaling pathway and that ROCK inhibition reduces that effect.

Journal Articles

Heavy-ion microbeam cell irradiation system at JAERI-Takasaki

Kobayashi, Yasuhiko; Funayama, Tomoo; Wada, Seiichi; Sakashita, Tetsuya; Kakizaki, Takehiko; Hamada, Nobuyuki*; Yokota, Yuichiro; Furusawa, Yoshiya*

KEK Proceedings 2005-5, p.6 - 8, 2005/10

no abstracts in English

Journal Articles

Effects of heavy-ion radiosurgery on the hemopoietic function of the silkworm ${it bombyx mori}$

Tu, Z.; Kobayashi, Yasuhiko; Kiguchi, Kenji*; Watanabe, Hiroshi; Yamamoto, Kazuo*

Journal of Radiation Research, 43(3), p.269 - 275, 2002/11

 Times Cited Count:10 Percentile:65.4(Biology)

no abstracts in English

Journal Articles

A New diagnostic method for electromagnetic field patterns of fast waves during FWCD experiments in JFT-2M

Saigusa, Mikio*; Kanazawa, Sadayoshi*; Ogawa, Toshihide; Kawashima, Hisato; Kikuchi, Kazuo; Ido, Takeshi*; Fukuyama, Atsushi*

Nuclear Fusion, 42(4), p.412 - 417, 2002/04

 Times Cited Count:1 Percentile:96.27(Physics, Fluids & Plasmas)

A new diagnostic method is proposed for direct measurements of electromagnetic field patterns of fast waves in toroidal plasmas. The fluctuation of ponderomotive potential at a beat wave frequency between the two frequency fast waves produces the actual potential fluctuation via electron and ion motions. A heavy ion beam probe (HIBP) detected the potential fluctuation patterns at a beat wave frequency during the fast wave pulse. The amplitude of potential fluctuations decreases with increasing an electron temperature in fast wave current drive (FWCD) experiments of JFT-2M, due to the improvement of wave absorption via electron Landau damping. The measured potential fluctuation does not contradict with the prediction using a full wave code calculations.

Journal Articles

Radiofrequency experiments in JFT-2M; Demonstration of innovative applications of a travelling wave antenna

Ogawa, Toshihide; Hoshino, Katsumichi; Kanazawa, Sadayoshi*; Saigusa, Mikio*; Ido, Takeshi*; Kawashima, Hisato; Kasuya, N.*; Takase, Yuichi*; Kimura, Haruyuki; Miura, Yukitoshi; et al.

Nuclear Fusion, 41(12), p.1767 - 1775, 2001/12

 Times Cited Count:21 Percentile:39.35(Physics, Fluids & Plasmas)

no abstracts in English

Journal Articles

Direct measurement of electromagnetic field pattern of fast wave in FWCD experiments using ponderomotive potential produced by beat wave in JFT-2M

Saigusa, Mikio*; Kanazawa, Sadayoshi; Ogawa, Toshihide; Ido, Takeshi*; Kawashima, Hisato; Kikuchi, Kazuo; Fukuyama, Atsushi*; Kamiya, Kensaku; JFT-2M Team

Proceedings of 2000 International Congress on Plasma Physics (ICPP 2000), Vol.3, p.844 - 847, 2000/00

no abstracts in English

Journal Articles

Effects of general and local irradiation of heavy ion beams on the development and morphogenesis of the silkworm, Bombyx mori

Tu, Z. L.*; Yamasaki, Shuhei*; Shirai, Koji*; Kanekatsu, Rensuke*; Kiguchi, Kenji*; Kobayashi, Yasuhiko; Taguchi, Mitsumasa; Watanabe, Hiroshi

Nippon Sanshigaku Zasshi, 68(6), p.443 - 453, 1999/00

no abstracts in English

Journal Articles

JAERI recoil mass separator

Ikezoe, Hiroshi; Nagame, Yuichiro; *; ; ; Otsuki, Tsutomu*

Nuclear Instruments and Methods in Physics Research A, 376, p.420 - 427, 1996/00

 Times Cited Count:36 Percentile:6.03

no abstracts in English

Journal Articles

Heavy ion beam microdosimetry

Namba, Hideki; Aoki, Yasushi; Furukawa, Katsutoshi; Ono, Shinichi; Komaki, Yoshihide

Dai-4-Kai Tandemu Kasokuki Oyobi Sono Shuhen Gijutsu No Kenkyukai Hokokushu, p.131 - 134, 1991/07

no abstracts in English

Journal Articles

JAERI tandem superconducting booster

Proc. of the 2nd Int. Symp. on Advanced Nuclear Energy Research; Evolution by Accelerators, p.357 - 361, 1990/00

no abstracts in English

Journal Articles

Preriminary operation results of JAERI ECR ion source octopus

Yokota, Wataru; Arakawa, Kazuo; Tachikawa, T.*; *; C.Dupont*; Y.Jongen*

Proc. of the 7th Symp. on Accelerator Science and Technology, p.68 - 70, 1989/00

no abstracts in English

Oral presentation

LET dependency of relative biological effectiveness in normal human dermal fibroblasts irradiated with carbon ion beam

Mizohata, Kensuke*; Yoshida, Yukari*; Matsumura, Akihiko*; Isono, Mayu*; Yako, Tomoko*; Ando, Koichi*; Funayama, Tomoo; Ono, Tatsuya*; Nakano, Takashi*; Kanai, Tatsuaki*

no journal, , 

Clinical RBE (cRBE), which was used to decide a clinical dose of carbon ion radiotherapy, is calculated by multiply experimental RBE (eRBE) by scaling factor. A value of eRBE was measured by colony formation assay of HSG cells in past, and adopted to the therapy of all patients and organ. However, there are question whether it was proper to use conventional eRBE in a different organization, different cell type. Therefore, we irradiated X-rays or a carbon line to NHDF cell and performed a colony assay to determine RBE of different cell type. The value of RBE was calculated from the cell survival rate fit in LQ model. As a result, the value of RBE was increased in LET-dependent manner, and the RBE obtained from the NHDF cell exhibited higher value than that of HSG cells. Thus, we concluded that it might be necessary to change scaling factor when evaluate different organ.

29 (Records 1-20 displayed on this page)