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Satou, Yukihiko; Sueki, Keisuke*; Sasa, Kimikazu*; Yoshikawa, Hideki; Nakama, Shigeo; Minowa, Haruka*; Abe, Yoshinari*; Nakai, Izumi*; Ono, Takahiro*; Adachi, Koji*; et al.
Geochemical Journal, 52(2), p.137 - 143, 2018/00
Times Cited Count:65 Percentile:97.21(Geochemistry & Geophysics)Ono, Takahiro*; Iizawa, Yushin*; Abe, Yoshinari*; Nakai, Izumi*; Terada, Yasuko*; Satou, Yukihiko; Sueki, Keisuke*; Adachi, Koji*; Igarashi, Yasuhito*
Bunseki Kagaku, 66(4), p.251 - 261, 2017/04
Times Cited Count:32 Percentile:79.36(Chemistry, Analytical)no abstracts in English
Endo, Kiyoshi*; Shibata, Yasushi*; Yamamoto, Tetsuya*; Nakai, Kei*; Matsumura, Akira*; Sato, Takahiro; Yokoyama, Akihito; Koka, Masashi; Okubo, Takeru; Yamazaki, Akiyoshi; et al.
JAEA-Review 2011-043, JAEA Takasaki Annual Report 2010, P. 86, 2012/01
Kotaki, Hideyuki; Kando, Masaki; Daito, Izuru; Kameshima, Takashi*; Kawase, Keigo*; Chen, L. M.*; Fukuda, Yuji; Koga, J. K.; Kiriyama, Hiromitsu; Kondo, Shuji; et al.
Japanese Journal of Applied Physics, 50(6), p.066401_1 - 066401_3, 2011/06
Times Cited Count:1 Percentile:4.8(Physics, Applied)Kotaki, Hideyuki; Daito, Izuru; Kando, Masaki; Hayashi, Yukio; Kawase, Keigo; Kameshima, Takashi*; Fukuda, Yuji; Homma, Takayuki; Ma, J.*; Chen, L. M.*; et al.
Physical Review Letters, 103(19), p.194803_1 - 194803_4, 2009/11
Times Cited Count:55 Percentile:88.11(Physics, Multidisciplinary)Kotaki, Hideyuki; Kando, Masaki; Daito, Izuru; Homma, Takayuki; Kameshima, Takashi; Kawase, Keigo; Chen, L.-M.*; Fukuda, Yuji; Kiriyama, Hiromitsu; Kondo, Shuji; et al.
AIP Conference Proceedings 1153, p.176 - 181, 2009/07
Kiriyama, Hiromitsu; Mori, Michiaki; Nakai, Yoshiki; Shimomura, Takuya*; Tanoue, Manabu*; Akutsu, Atsushi; Okada, Hajime; Motomura, Tomohiro*; Kondo, Shuji; Kanazawa, Shuhei; et al.
JAEA-Conf 2008-007, p.13 - 16, 2008/08
One of the main bottlenecks for the applications of ultrashort and ultrahigh-peak power lasers in high-field physics is a temporal contrast of the pulses. In ultrahigh-peak power lasers, a nanosecond background of the amplified spontaneous emission (ASE) is generated at the same time as the femtosecond pulse. This background is mostly generated in the preamplifier (regenerative, multipass amplifier). Even though the contrast level is usually in the range from 10 to 10, this level is not sufficiently low at relativistic intensities greater than 10W/cm to avoid unwanted pre-plasmas generation. We demonstrated a high-contrast, high-peak power laser with optical parametric chirped-pulse amplification (OPCPA). With the use of OPCPA, contrast is enhanced to better than 710 in a few picoseconds before the main pulse, which corresponds to an improvement of three to four orders in magnitude compared with conventional systems.
Matsuda, Masahide*; Yamamoto, Tetsuya*; Nakai, Kei*; Endo, Kiyoshi*; Kumada, Hiroaki; Kageji, Teruyoshi*; Matsumura, Akira*
Proceedings of 12th International Congress on Neutron Capture Therapy (ICNCT-12), p.40 - 42, 2006/10
To describe the failure patterns and survival seen with high-grade glioma treated with BNCT, the dose distribution and the clinical responses were retrospectively analyzed. BSH-based BNCT was performed in 12 patients with high-grade glioma (grade IV 7, grade III 5). The post-diagnosis median survival time of 12 patients was 19.8 months (range 3.3-47.2). Four cases of local control, 3 of local recurrence, 3 of distant intraparenchymal recurrence and 2 of subarachnoid dissemination were recorded. According to the analysis of the failure patterns, minimum GTV dose of 26 GyEq or more is necessary for local control.
Fujioka, Shinsuke*; Nishimura, Hiroaki*; Nishihara, Katsunobu*; Sasaki, Akira; Sunahara, Atsushi*; Okuno, Tomoharu*; Ueda, Nobuyoshi*; Ando, Tsuyoshi*; Tao, Y.*; Shimada, Yoshinori*; et al.
Physical Review Letters, 95(23), p.235004_1 - 235004_4, 2005/12
Times Cited Count:144 Percentile:95.59(Physics, Multidisciplinary)no abstracts in English
Shibata, Yasushi*; Yamamoto, Kazuyoshi; Matsumura, Akira*; Yamamoto, Tetsuya*; Hori, Naohiko; Kishi, Toshiaki; Kumada, Hiroaki; Akutsu, Hiroyoshi*; Yasuda, Susumu*; Nakai, Kei*; et al.
JAERI-Research 2005-009, 41 Pages, 2005/03
The measurement of neutron flux and boron concentration in the blood during medical irradiation is indispensable in order to evaluate the radiation in boron neutron capture therapy. It is, however, difficult to measure the blood boron concentration during neutron irradiation because access to the patient is limited. Therefore we prospectively investigated the predictability of blood boron concentrations using the data obtained at the first craniotomy after infusion of a low dosage of BSH. When the test could not be carried out, the blood boron concentration during irradiation was also predicted by using the 2-compartment model. If the final boron concentration after the end of the infusion is within 95% confidence interval of the prediction, direct prediction from biexponential fit will reduce the error of blood boron concentrations during irradiation to around 6%. If the final boron concentration at 6 or 9 hours after the end of infusion is out of 95% confidence interval of the prediction, proportional adjustment will reduce error and expected error after adjustment to around 12%.
Matsumura, Akira*; Zhang, T.*; Nakai, Kei*; Endo, Kiyoshi*; Kumada, Hiroaki; Yamamoto, Tetsuya*; Yoshida, Fumiyo*; Sakurai, Yoshinori*; Yamamoto, Kazuyoshi; Nose, Tadao*
Journal of Experimental and Clinical Cancer Research, 24(1), p.93 - 98, 2005/03
no abstracts in English
Shimada, Yoshinori*; Nishimura, Hiroaki*; Nakai, Mitsuo*; Hashimoto, Kazuhisa*; Yamaura, Michiteru*; Tao, Y.*; Shigemori, Keisuke*; Okuno, Tomoharu*; Nishihara, Katsunobu*; Kawamura, Toru*; et al.
Applied Physics Letters, 86(5), p.051501_1 - 051501_3, 2005/01
Times Cited Count:111 Percentile:94.28(Physics, Applied)no abstracts in English
Kumada, Hiroaki; Yamamoto, Kazuyoshi; Yamamoto, Tetsuya*; Nakai, Kei*; Nakagawa, Yoshinobu*; Kageji, Teruyoshi*; Matsumura, Akira*
Applied Radiation and Isotopes, 61(5), p.1045 - 1050, 2004/11
Times Cited Count:11 Percentile:58.63(Chemistry, Inorganic & Nuclear)To carry out the BNCT clinical trials based on accurate dosimetry of several absorbed doses given to a patient, we have developed JCDS which can determine the absorbed doses by numerical simulation. The aim of this study is to improve the accuracy of the BNCT dosimetry efficiently. We have developed the multi-voxel calculation method reconstructing the original voxel model by combining of several voxel cell sizes such as in 5mm, 10mm and 20mm voxel cell. To verify the accuracy of the multi-voxel method, the calculation results were compared with the phantom experimental data. These results proved that the multi-voxel calculation enables JCDS to more accurately estimate the absorbed doses to a patient by efficient calculations.
Yamamoto, Tetsuya*; Matsumura, Akira*; Nakai, Kei*; Shibata, Yasushi*; Endo, Kiyoshi*; Sakurai, Fumio; Kishi, Toshiaki; Kumada, Hiroaki; Yamamoto, Kazuyoshi; Torii, Yoshiya
Applied Radiation and Isotopes, 61(5), p.1089 - 1093, 2004/11
Times Cited Count:53 Percentile:94.47(Chemistry, Inorganic & Nuclear)no abstracts in English
Yoshida, Fumiyo*; Matsumura, Akira*; Yamamoto, Tetsuya*; Kumada, Hiroaki; Nakai, Kei*
Cancer Letters, 215(1), p.61 - 67, 2004/11
Times Cited Count:13 Percentile:22.52(Oncology)Sodium borocaptate (BSH) is widely used for Boron Neutron Capture Therapy (BNCT) of brain tumors. However, the mechanism of uptake by the tumor remains unclear. We investigated the sulfhydryl moiety of this compound. Down regulation of glutathione (GSH) by buthionine sulfoximine (BSO) in cultured cells resulted in increase of BSH uptake (7.9 %-36.5 %) compared to control group and subsequently cytocidal effect of neutron irradiation also increased. The radiation damage by -ray irradiation was suppressed by enhancement of BSH uptake. These findings suggested that modulation of GSH induce enhancement effect of B(n,) reaction and protective effect of secondary -ray in BNCT.
Yamamoto, Kazuyoshi; Kumada, Hiroaki; Nakai, Kei*; Endo, Kiyoshi*; Yamamoto, Tetsuya*; Matsumura, Akira*
Proceedings of 11th World Congress on Neutron Capture Therapy (ISNCT-11) (CD-ROM), 14 Pages, 2004/10
A dose distribution considered the tumor cell density distribution is required on the radiation therapy. We propose a novel method of determining target region considering the tumor cell concentration as a new function for the next generation Boron Neutron Capture Therapy (BNCT) dosimetry system. It has not been able to sufficiently define the degree of microscopic diffuse invasion of the tumor cells peripheral to a tumor bulk in malignant glioma using current medical imaging. Referring to treatment protocol of BNCT, the target region surrounding the tumor bulk has been set as the region which expands at the optional distance with usual 2cm margin from the region enhanced on T1 weighted gadolinium Magnetic Resonance Imaging (MRI). In this research, the cell concentration of the region boundary of the target was discussed by using tumor cell diffusion model in the sphere spatio-temporal system. The survival tumor cell density distribution after the BNCT irradiation was predicted by the two regions diffusion model for a virtual brain phantom.
Endo, Kiyoshi*; Shibata, Yasushi*; Yoshida, Fumiyo*; Nakai, Kei*; Yamamoto, Tetsuya*; Matsumura, Akira*; Ishii, Keizo*; Sakai, Takuro; Sato, Takahiro; Oikawa, Masakazu*; et al.
Proceedings of 11th World Congress on Neutron Capture Therapy (ISNCT-11) (CD-ROM), 2 Pages, 2004/10
Micro PIXE, which is installed in a single end accelerator in JAERI, was used for quantitative analysis of boron and gadolinium distribution in a cell level. The micro beam of 1 m diameter is possible to observe the distribution. In the adjustment procedure of the sample, first is a fix of mylar film by using a glass ring and a bite ring of 2cm diameter. Next the 9L cells were scattered on the washed film, and is cultivated on 37C in medium until they form the mono-layer. After the Gd-BOPTA was added, it incubates for the 24-72 hour on 37C. The film is washed in the THAM liquid, and is directly put on liquid nitrogen. A vacuum drying for 24 hours is conducted in order to fix a film on holder. It is important to uniformly fix the cell in distribution analysis in the cell using Micro PIXE. In recent result, it became possible that the distribution of P, S, Gd, etc. was analyzed. But we could not distinguish whether K and Gd exist in the cell or whether it exists around the cell. It was indicated that these elements was leaked by the reason of cell breaking or other on the cytoplasm.
Shibata, Yasushi*; Matsumura, Akira*; Yamamoto, Tetsuya*; Akutsu, Hiroyoshi*; Yasuda, Susumu*; Nakai, Kei*; Nose, Tadao*; Yamamoto, Kazuyoshi; Kumada, Hiroaki; Hori, Naohiko; et al.
Research and Development in Neutron Capture Therapy, p.1055 - 1060, 2002/09
We prospectively investigated the predictability of blood boron concentrations using the data obtained at the first craniotomy after infusion of a low dose of sodium undecahydroclosododecaborate (BSH). Nine patients with malignant glial tumors underwent Boron neutron capture therapy (BNCT) at the Japan Atomic Energy Research Institute (JAERI) between 1995 and 2001. In 7 patients, 1g of BSH was infused before the first tumor removal and boron concentrations were determined using prompt gamma ray analysis (PGA). Then, 12 hours before BNCT, patients were infused at a dose of 100mg/kg BSH, and the boron concentrations were determined again. The boron biodistribution data showed a biexponential pharmacokinetic profile. If the final boron concentration at 6 or 9 hours after the end of the infusion is within the 95% confidence interval of the prediction, direct prediction from biexponential fit will reduce the error of blood boron concentrations during irradiation to around 6%.
Matsumura, Akira*; Yamamoto, Tetsuya*; Shibata, Yasushi*; Nakai, Kei*; Zhang, T.*; Akutsu, Hiroyoshi*; Matsushita, Akira*; Yasuda, Susumu*; Takano, Shingo*; Nose, Tadao*; et al.
Posuto Shikuensu Jidai Ni Okeru Noshuyo No Kenkyu To Chiryo, p.427 - 435, 2002/07
no abstracts in English
Nose, Tadao*; Matsumura, Akira*; Yamamoto, Tetsuya*; Shibata, Yasushi*; Yoshida, Fumiyo*; Akutsu, Hiroyoshi*; Yasuda, Susumu*; Matsushita, Akira*; Nakai, Kei*; Yamada, Takashi*; et al.
UTRCN-G-29, p.114 - 123, 2001/00
no abstracts in English