Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
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 
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 .
Kanai, Akihiko*; Park, C.*; Noborio, Kazuyuki*; Kasada, Ryuta*; Konishi, Satoshi*; Hirose, Takanori; Nozawa, Takashi; Tanigawa, Hiroyasu
Fusion Engineering and Design, 89(7-8), p.1653 - 1657, 2014/10
Times Cited Count：4 Percentile：30.92(Nuclear Science & Technology)Takahashi, Akihisa*; Kubo, Makoto*; Ma, H.*; Nakagawa, Akiko*; Yoshida, Yukari*; Isono, Mayu*; Kanai, Tatsuaki*; Ono, Tatsuya*; Furusawa, Yoshiya*; Funayama, Tomoo; et al.
Radiation Research, 182(3), p.338 - 344, 2014/09
Times Cited Count：57 Percentile：90.66(Biology)To clarify whether high-LET radiation inhibits all repair pathways or specifically one repair pathway, studies were designed to examine the effects of radiation with different LET values on DNA DSB repair and radiosensitivity. Embryonic fibroblasts bearing repair gene KO were exposed to X rays, carbon-, iron-, neon- and argon-ion beams. Cell survival was measured with colony-forming assays. The sensitization enhancement ratio (SER) values were calculated using the 10% survival dose of wild-type cells and repair-deficient cells. Cellular radiosensitivity was listed in descending order: double-KO cells 
NHEJ-KO cells HR-KO cells wild-type cells. Although HR-KO cells had an almost constant SER value, NHEJ-KO cells showed a high-SER value when compared to HR-KO cells, even with increasing LET values. These results suggest that with carbon-ion therapy, targeting NHEJ repair yields higher radiosensitivity than targeting homologous recombination repair.
Agematsu, Takashi; Uno, Sadanori; Chiba, Atsuya; Yamada, Keisuke; Yokoyama, Akihito; Saito, Yuichi; Ishii, Yasuyuki; Sato, Takahiro; Okubo, Takeru; Yokota, Wataru; et al.
JAEA-Review 2011-043, JAEA Takasaki Annual Report 2010, P. 173, 2012/01
Three electrostatic accelerators of TIARA were operated smoothly in FY 2010, and all the planned experiments were carried out except those canceled by users or the impact of Great East Japan Earthquake on March 11, 2011. On the other hand, Saturday operation for experiments was carried out after October on the Global Nuclear-Human Resource Development Initiative. The yearly operation time of the tandem accelerator, the single-ended accelerator and the ion implanter amounted to 2116, 2367 and 1800 hours, respectively, which were similar to those of usual years. Regarding the single-ended accelerator, the generator in the high-voltage terminal failed and was replaced with new one. A switching magnet was installed for a new branch beam line of the ion implanter. As to the tandem accelerator, In ion was generated and accelerated at intensity of 500 nA.
Uno, Sadanori; Chiba, Atsuya; Yamada, Keisuke; Yokoyama, Akihito; Agematsu, Takashi; Kitano, Toshihiko*; Takayama, Terumitsu*; Orimo, Takao*; Kanai, Shinji*; Aoki, Yuki*; et al.
Dai-24-Kai Tandemu Kasokuki Oyobi Sono Shuhen Gijutsu No Kenkyukai Hokokushu, p.125 - 128, 2011/07
The yearly operation time of three electrostatic accelerators at TIARA of Japan Atomic Energy Agency is keeping the same level since 2000, the tandem accelerator, the ion implanter and the single-ended accelerator amounted to about 2000, 1900 and 2500 hours, respectively. Three electrostatic accelerators did not have damage when the Tohoku Earthquake occurred on March 11, 2011. However, these accelerators were not able to operate during the planned power outage by Tokyo Electric Power Company (TEPCO). The tandem accelerator accelerated ion beam of In, which gave intensity of 500nA with stability. Additionally, the ion implanter generated maximum 400nA at ion beam of Gd, which was used in experiments for the users.
Agematsu, Takashi; Uno, Sadanori; Chiba, Atsuya; Yamada, Keisuke; Yokoyama, Akihito; Saito, Yuichi; Ishii, Yasuyuki; Sato, Takahiro; Okubo, Takeru; Yokota, Wataru; et al.
JAEA-Review 2010-065, JAEA Takasaki Annual Report 2009, P. 181, 2011/01
Three electrostatic accelerators of TIARA were operated smoothly in FY 2009, and all the planned experiments were carried out except those canceled by users. The yearly operation time of the tandem accelerator, the single-ended accelerator and the ion implanter amounted to 2100, 2416 and 1866 hours, respectively. Regarding the single-ended accelerator, the radio frequency oscillator of the ion source mounted in high-voltage terminal and the sequencer for control of the SB beam line failed, and they were replaced. The oven controller of Freeman ion source of the ion implanter was renewed. As to the tandem accelerator, Mn ion was successfully generated and accelerated with intensity of 150 nA.
Chiba, Atsuya; Uno, Sadanori; Yamada, Keisuke; Yokoyama, Akihito; Agematsu, Takashi; Yokota, Wataru; Kitano, Toshihiko*; Takayama, Terumitsu*; Kanai, Shinji*; Orimo, Takao*; et al.
Dai-23-Kai Tandemu Kasokuki Oyobi Sono Shuhen Gijutsu No Kenkyukai Hokokushu, p.119 - 122, 2010/11
Operation times of each accelerator are keeping the same level as in recent 10 years, Tandem accelerator, Single-ended and Ion implanter amounted to about 2,000, 2,500 and 1,900 hours, respectively. In the last fiscal year, we succeeded in maintaining the terminal voltage of the tandem accelerator to high stability for long periods by exchanging the material of a corona-probe needle to the tungsten (NPS Co.). In the ion-implanter, the oven control system equipped with the Freeman ion source was renewed. There was no trouble to affect on the machine-time in the last fiscal year, so the all planned experiments were carried out.
Fujishita, Hideshi*; Hayashi, Makoto*; Kanai, Takashi*; Yamada, Takahiro*; Igawa, Naoki; Kihara, Kuniaki*
Journal of Physics and Chemistry of Solids, 71(9), p.1285 - 1289, 2010/09
Times Cited Count：3 Percentile：17.17(Chemistry, Multidisciplinary)Atomic displacements are order parameters for displacive structural phase transitions. The temperature evolution of Si atomic displacement in quartz was analyzed by studying the quantum expansion of the Landau potential. The expansion was found to accurately describe the evolution of the atomic displacement over the entire temperature interval. A proportional relationship between spontaneous strain and the square of the atomic displacement was observed over the entire temperature interval.
Hayashi, Makoto*; Kanai, Takashi*; Yamada, Takahiro*; Fujishita, Hideshi*; Igawa, Naoki; Kihara, Kuniaki*
no journal, ,
While the temperature change of the static order paramaters, such as an atom displacement and lattice destortion around the phase transition temperature is exlained by the classical Landau theory, the tempereture dependence of those parameters below the transition temperature was predicted by Salje. In this report, temperature dependence of strucural parameters of quartz was measured using the nuetron powder diffraction and analyzed by the Rietveld method to confirm the theory predicted by Salje. The quantitative analysis of present works gave a good agreement with the theory.
Hayashi, Makoto*; Fujishita, Hideshi*; Kanai, Takashi*; Yamada, Takahiro*; Igawa, Naoki; Kihara, Kuniaki*
no journal, ,
A phenomenological theory describes the temperature dependence of the order parameter Q, which is atomic shift in displacement structural phase transition and of strain e, which is coupled to Q, near a phase transition. Recently, Romero and Salje showed the strain obeys the quantum phenomenological theory below the temperature of the displacement structural phase transition. However, direct evaluation of the quantum phenomenological theory by measuring the order parameters in entire temperature is required to verify the effectiveness of the theory. We carried out the structural analysis of quartz by neutron powder diffraction in the temperature range of 10-250K. We found that the strain was in proportion to the squares of the displacement of the Si atom along the a-axis in the present temperature range. The effectiveness of the theory was directly verified by the atomic displacement.
Agematsu, Takashi; Uno, Sadanori; Chiba, Atsuya; Yamada, Keisuke; Yokoyama, Akihito; Saito, Yuichi; Ishii, Yasuyuki; Sato, Takahiro; Okubo, Takeru; Yokota, Wataru; et al.
no journal, ,
Three electrostatic accelerators of TIARA were operated smoothly in FY 2009, and all the planned experiments were carried out except those canceled by users. The yearly operation time of the tandem accelerator, the single-ended accelerator and the ion implanter amounted to 2100, 2416 and 1866 hours, respectively. Regarding the tandem accelerator, the voltage probe needle made of tungsten was replaced with that of nickel-plating metal, and a initial stability of high voltage was maintained for 500 hours as a result. The radio frequency oscillator of the ion source mounted in high-voltage terminal of the single-ended accelerator and the sequencer for control of one of beam line failed and renewed. The superannuated oven controller of Freeman ion source of the ion implanter was replaced with new one. An ion beam of Mn was newly developed with intensity of 150 nA in order to expand ion species for the tandem accelerator.
Uno, Sadanori; Chiba, Atsuya; Yamada, Keisuke; Yokoyama, Akihito; Agematsu, Takashi; Saito, Yuichi; Ishii, Yasuyuki; Sato, Takahiro; Okubo, Takeru; Yokota, Wataru; et al.
no journal, ,
The yearly operation time of three electrostatic accelerators at TIARA of Japan Atomic Energy Agency in 2010 was the tandem accelerator, the ion implanter and the single-ended accelerator amounted to 2,116, 1,800 and 2,367 hours, respectively. The tandem accelerator operated smoothly in this year, but stop times by trouble of the ion implanter and the single-ended accelerator was 1 and 2 times, respectively. Three electrostatic accelerators did not have damage when the Tohoku Earthquake occurred on March 11, 2011. However, these accelerators were not able to operate during the planned power outage by Tokyo Electric Power Company (TEPCO). The tandem accelerator accelerated ion beam of In, which gave intensity of 500 nA with stability. Additionally, the ion implanter generated maximum 400 nA at ion beam of Gd, which was used in experiments for the users.
Nakagawa, Takahiro; Takada, Chie; Kanai, Katsuta; Murayama, Takashi; Miyauchi, Hideaki; Suzuki, Takehiko; Sato, Yoshitaka; Ezaki, Hiroko; Imahashi, Atsushi; Isozaki, Kohei; et al.
no journal, ,
no abstracts in English
Ikeda, Hiroko; Yokota, Yuichiro; Funayama, Tomoo; Kanai, Tatsuaki*; Nakano, Takashi*; Kobayashi, Yasuhiko
no journal, ,
Human lung normal fibroblasts WI-38 and human lung cancer cells H1299/wt
were used. Cells were irradiated with carbon-ion broad beams (LET=108 keV/ 
m), then survival rates of bystander cells after co-culture with irradiated cells were measured using colony formation assay. The survival rates of non-irradiated H1299/wt cells co-cultured with 0.13 Gy irradiated WI-38 increased after 6 and 24 h of co-culture. On the other hand, the bystander cells co-cultured with 0.5 Gy irradiated WI-38 showed decreased survival rates. The survival rates of bystander H1299/wt cells showed a tendency to increase by the addition of Carboxy-PTIO to the co-culture medium, when co-cultured with 0.5 Gy irradiated WI-38. From these results, reduction of survival rates is likely to be caused by NO radical as a mediator in bystander effects between lung normal and cancer cells. However, it is suggested that there might be other signals participated in an increase of survival rates.
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.
Ikeda, Hiroko; Yokota, Yuichiro; Funayama, Tomoo; Kanai, Tatsuaki*; Nakano, Takashi*; Kobayashi, Yasuhiko
no journal, ,
In this study, human lung normal fibroblasts WI-38 and human lung cancer cells H1299/wt were used. Cells were irradiated with carbon-ion broad beams, then survival rates of bystander cells after co-culture with irradiated cells were measured using colony assay. The survival rates of non-irradiated bystander cancer cells co-cultured with 0.13 Gy irradiated normal cells increased after 6-hours co-culture. On the other hand, the bystander cells co-cultured with 0.5 Gy irradiated normal cells showed decreased survival rates. These results indicated that the bystander responses of the cancer cells changes according to the irradiation dose on the normal cells. In addition, the survival rates of bystander cancer cells showed a tendency to increase by the addition of Carboxy-PTIO to the co-culture medium, when co-cultured with 0.5 Gy irradiated normal cells. From these results, reduction of survival rates is likely to be caused by NO radical as a mediator in bystander effects.
Ikeda, Hiroko; Yokota, Yuichiro; Funayama, Tomoo; Kanai, Tatsuaki*; Nakano, Takashi*; Kobayashi, Yasuhiko
no journal, ,
There have been some reports on bystander effects induced by proton microbeam in contact co-cultured different type cells, but there are few reports using heavy-ion microbeam. So, we have established a new contact co-culture system between human lung normal fibroblast cell line WI-38 and human lung cancer cell line H1299/wt in the same dish. We have also adapted patterning irradiation systems which automatically irradiated to cancer cells (or normal cells) in a certain range by making use of the target cell irradiation technique at JAEA-Takasaki. Thereby, we were able to successively irradiate to 250 sites of confluent cancer area (lengthwise: 5 mm) so as not to overlap the irradiated range, using carbon-ion microbeam collimated by aperture of 
20 m. Now, we are analyzing DNA damage and repair of patterning irradiation samples by evaluating focus numbers of immunostained 53BP1 and 
-H2AX. The details of the method and findings will be reported in the talk.
