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Journal Articles

Nanoscopic structural investigation of physically cross-linked nanogels formed from self-associating polymers

Sekine, Yurina; Endo, Hitoshi*; Iwase, Hiroki*; Takeda, Shigeo*; Mukai, Sadaatsu*; Fukazawa, Hiroshi; Littrell, K. C.*; Sasaki, Yoshihiro*; Akiyoshi, Kazunari*

Journal of Physical Chemistry B, 120(46), p.11996 - 12002, 2016/11

 Times Cited Count:9 Percentile:32.16(Chemistry, Physical)

The detailed structure of a nanogel formed by self-association of cholesterol-bearing pullulans (CHP) was determined by contrast variation small-angle neutron scattering. The decomposition of scattering intensities into partial scattering functions of each CHP nanogel component, i.e., pullulan, cholesterol, and the cross-term between the pullulan and the cholesterol allows us to investigate the internal structure of the nanogel. The effective spherical radius of the skeleton formed by pullulan chains was found to be about 8.1 nm. In the CHP nanogel, there are about 19 cross-linking points where a cross-linking point is formed by aggregation of trimer cholesterol molecules with the spatially inhomogeneous distribution of the mass fractal dimension of 2.6. The average radius of the partial chains can also be determined to be 1.7 nm. As the result, the complex structure of the nanogels is coherently revealed at the nanoscopical level.

Journal Articles

22A beam production of the uniform negative ions in the JT-60 negative ion source

Yoshida, Masafumi; Hanada, Masaya; Kojima, Atsushi; Kashiwagi, Mieko; Grisham, L. R.*; Hatayama, Akiyoshi*; Shibata, Takanori*; Yamamoto, Takashi*; Akino, Noboru; Endo, Yasuei; et al.

Fusion Engineering and Design, 96-97, p.616 - 619, 2015/10

 Times Cited Count:10 Percentile:73.32(Nuclear Science & Technology)

In JT-60 Super Advanced for the fusion experiment, 22A, 100s negative ions are designed to be extracted from the world largest ion extraction area of 450 mm $$times$$ 1100 mm. One of the key issues for producing such as high current beams is to improve non-uniform production of the negative ions. In order to improve the uniformity of the negative ions, a tent-shaped magnetic filter has newly been developed and tested for JT-60SA negative ion source. The original tent-shaped filter significantly improved the logitudunal uniformity of the extracted H$$^{-}$$ ion beams. The logitudinal uniform areas within a $$pm$$10 deviation of the beam intensity were improved from 45% to 70% of the ion extraction area. However, this improvement degrades a horizontal uniformity. For this, the uniform areas was no more than 55% of the total ion extraction area. In order to improve the horizontal uniformity, the filter strength has been reduced from 660 Gasus$$cdot$$cm to 400 Gasus$$cdot$$cm. This reduction improved the horizontal uniform area from 75% to 90% without degrading the logitudinal uniformity. This resulted in the improvement of the uniform area from 45% of the total ion extraction areas. This improvement of the uniform area leads to the production of a 22A H$$^{-}$$ ion beam from 450 mm $$times$$ 1100 mm with a small amount increase of electron current of 10%. The obtained beam current fulfills the requirement for JT-60SA.

Journal Articles

Mass production results of superconducting cables for CS and EF coils of JT-60SA

Sugimoto, Masahiro*; Kosugi, Keizo*; Katayama, Kota*; Ii, Hideki*; Takagi, Akira*; Endo, Sakaru*; Shimizu, Hitoshi*; Tsubouchi, Hirokazu*; Kizu, Kaname; Yoshida, Kiyoshi

Proceedings of 24th International Cryogenic Engineering Conference (ICEC 24) and International Cryogenic Materials Conference 2012 (ICMC 2012) (CD-ROM), p.799 - 802, 2012/05

We have successfully manufactured all superconducting cables for CS and EF coils of JT-60SA. The low temperature performance of superconducting wires satisfied the specifications under sufficiently low deviations and high production yields. Ni-plated strands of EF cables having the larger sliding friction between strands than that of Cr-plated strands of CS cable caused difficulties on the cabling without any defects. Consequently, the newly developed cabling techniques with the original inspection apparatus significantly enhanced the manufacturability and were effective for guarantee of the quality.

Journal Articles

The Analysis of boron micro-distribution in 9L gliosarmoma cells and HUVEC cells using PIXE and PIGE

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

JAEA Reports

Replacement technology for front acrylic panels of a large-sized glove box using bag-in / bag-out method

Sakuraba, Naotoshi; Numata, Masami; Komiya, Tomokazu; Ichise, Kenichi; Nishi, Masahiro; Tomita, Takeshi; Usami, Koji; Endo, Shinya; Miyata, Seiichi; Kurosawa, Tatsuya; et al.

JAEA-Technology 2009-071, 34 Pages, 2010/03

JAEA-Technology-2009-071.pdf:21.07MB

As a part of maintenance technology of a large-sized glove box for handling of TRU nuclides, we developed replacement technology for front acrylic panels using the bag-in/bag-out method and applied this technology to replace the deteriorated front acrylic panels at Waste Safety Testing Facility (WASTEF) in Nuclear Science Research Institute of Japan Atomic Energy Agency (JAEA). As a consequence, we could safely replace the front acrylic panels under the condition of continuous negative pressure only with partial decontamination of the glove box. We also demonstrated that the present technology is highly effective in points of safety, workability and cost as compared to the usual replacement technology for front acrylic panels of a glove box, where workers in an air-line suit replace directly the front acrylic panels in a green house.

Journal Articles

Proton irradiation effects on tensile and bend-fatigue properties of welded F82H specimens

Saito, Shigeru; Kikuchi, Kenji*; Hamaguchi, Dai; Usami, Koji; Ishikawa, Akiyoshi; Nishino, Yasuharu; Endo, Shinya; Kawai, Masayoshi*; Dai, Y.*

Journal of Nuclear Materials, 398(1-3), p.49 - 58, 2010/03

 Times Cited Count:6 Percentile:43.83(Materials Science, Multidisciplinary)

In several institutes, R&D for an ADS have been progressed. Ferritic / martensitic (F/M) steels are the candidate material for the beam window. To obtain the irradiation data, the PIE work of the SINQ target irradiation program (STIP) specimens was carried out at JAEA. In this study, the results of PIE on F/M steel F82H and its welded joint will be reported. The results of tensile tests indicate that the irradiation hardening occurred with increasing dpa up to 10.1 dpa below 320$$^{circ}$$C irradiation. At higher dose (- 11.8 dpa) and higher temperature (- 380$$^{circ}$$C), irradiation hardening and degradation of ductility relaxed. In this study, all specimens kept its ductility after irradiation and fractured in ductile manner. The fatigue life of F82H base metal is almost the same as that of unirradiated specimens. Though the number of specimen is limited, the fatigue life of F82H EB welded joints seems to increase after irradiation. The fracture surfaces of the specimens showed transgranular morphology. While F82H TIG welded specimens were not fractured by 10$$^{7}$$ cycles.

Journal Articles

Microdosimetric study for secondary neutrons in phantom produced by a 290 MeV/nucleon carbon beam

Endo, Satoru*; Tanaka, Kenichi*; Takada, Masashi*; Onizuka, Yoshihiko*; Miyahara, Nobuyuki*; Sato, Tatsuhiko; Ishikawa, Masayoshi*; Maeda, Naoko*; Hayabuchi, Naofumi*; Shizuma, Kiyoshi*; et al.

Medical Physics, 34(9), p.3571 - 3578, 2007/09

 Times Cited Count:7 Percentile:27.75(Radiology, Nuclear Medicine & Medical Imaging)

Absorbed doses from main charged particle beams and charged-particle fragments have been measured with high accuracy for particle therapy but there are few reports for doses from neutron components produced as fragments. This study describes measurements on neutron dose produced by carbon beam, microdosimetric distributions of secondary neutrons produced by 290 MeV/nucleon carbon beams have been measured by using a tissue equivalent proportional counter (TEPC) at the Heavy Ion Medical Accelerator in Chiba (HIMAC) at the National Institute of Radiological Sciences (NIRS). The ratios of neutrons to charged particle fragments dominated to be 11 to 89 % in the absorbed doses at the side and below the faces of the acrylic phantom (300 mm height $$times$$ 300 mm width $$times$$ 253 mm thickness).

JAEA Reports

Effect of neptunium ions on corrosion of stainless steel in nitric acid solution

Motooka, Takafumi; Ishikawa, Akiyoshi; Numata, Masami; Endo, Shinya; Itonaga, Fumio; Kiuchi, Kiyoshi; Kizaki, Minoru

JAEA-Research 2007-031, 20 Pages, 2007/03

JAEA-Research-2007-031.pdf:2.0MB

An effect of neptunium ions on corrosion of stainless steel in nitric acid solution was investigated by corrosion tests. Type SUS304L stainless steel was used for the tests. The corrosion tests were conducted in 9kmol/m$$^{3}$$ nitric acid solutions containing neptunium ions, where test specimens were immersed or heat-transferred. As a result, we found that neptunium ions promote corrosion of stainless steels in nitric acid solution. This finding would contribute to modifications of the materials for spent fuel reprocessing process.

Journal Articles

Failure patterns of high-grade glioma treated with BNCT

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.

Journal Articles

Combination of boron and gadolinium compounds for neutron capture therapy; An $$in Vitro$$ study

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

Journal Articles

Current clinical results of the Tsukuba BNCT trial

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:43 Percentile:93.25(Chemistry, Inorganic & Nuclear)

no abstracts in English

Journal Articles

Application of invasion mathematical model in dosimetry for boron neutron capture therapy for malignant glioma

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.

Journal Articles

Analysis of intracellular distribution of boron and gadolinium in 9L sarcoma cells using a single-ended accelerator (Micro PIXE)

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 $$mu$$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 37$$^{circ}$$C in medium until they form the mono-layer. After the Gd-BOPTA was added, it incubates for the 24-72 hour on 37$$^{circ}$$C. 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.

JAEA Reports

Production of a faithful realistic phantom to human head and thermal neutron flux measurement on the brain surface (Cooperative research)

Yamamoto, Kazuyoshi; Kumada, Hiroaki; Kishi, Toshiaki; Torii, Yoshiya; Endo, Kiyoshi*; Yamamoto, Tetsuya*; Matsumura, Akira*; Uchiyama, Junzo; Nose, Tadao*

JAERI-Tech 2002-092, 23 Pages, 2002/12

JAERI-Tech-2002-092.pdf:5.22MB

Thermal neutron flux is determined using the gold wires in current BNCT irradiation, so evaluation of arbitrary points after the irradiation is limited in the quantity of these detectors. In order to make up for the weakness, dose estimation of a patient is simulated by a computational dose calculation supporting system. In another way without computer simulation, a medical irradiation condition can be replicate experimentally using of realistic phantom which was produced from CT images by rapid prototyping technique. This phantom was irradiated at a same JRR-4 neutron beam as clinical irradiation condition of the patient and the thermal neutron distribution on the brain surface was measured in detail. This experimental evaluation technique using a realistic phantom is applicable to in vitro cell irradiation experiments for radiation biological effects as well as in-phantom experiments for dosimetry under the nearly medical irradiation condition of patient.

Journal Articles

Intraoperative boron neutron capture therapy using thermal/epithermal mixed beam

Matsumura, Akira*; Yamamoto, Tetsuya*; Shibata, Yasushi*; Nakai, Kei*; Zhang, T.*; Matsushita, Akira*; Takano, Shingo*; Endo, Kiyoshi*; Akutsu, Hiroyoshi*; Yamamoto, Kazuyoshi; et al.

Research and Development in Neutron Capture Therapy, p.1073 - 1078, 2002/09

Since 1998 to 2002, a new clinical trial of an intraoperative boron neutron capture therapy (IOBNCT) at JRR-4 of Japan Atomic Energy Institute (JAERI) using BSH with mixed thermal/epithermal neutron beam has been accomplished. There have been 9 patients included in this study. The median survival time (MST) in GBM was 19.8 months and 16.8 months in AA. IOBNCT with mixed thermal/epithermal neutron beam provide better primary radiation effect than conventional therapy in selected cases. Our phase I/II clinical trial was effective in local tumor control. Further clinical trial with new design should be performed to prove the efficacy of IOBNCT.

Journal Articles

Comparison of dosimetry by the realistic patient head phantom and by the patient's brain, and the JCDS calculation; A Clinical dosimetry study

Endo, Kiyoshi*; Matsumura, Akira*; Yamamoto, Tetsuya*; Nose, Tadao*; Yamamoto, Kazuyoshi; Kumada, Hiroaki; Kishi, Toshiaki; Torii, Yoshiya; Kashimura, Takanori*; Otake, Shinichi*

Research and Development in Neutron Capture Therapy, p.425 - 430, 2002/09

Using the Rapid Prototyping Technique, we produced a realistic phantom as a formative model of a patient head. This realistic phantom will contribute to verification of our planning system. However, cross-correlation among the calculations using the JAERI Computational Dosimetry System (JCDS), the realistic phantom, and the in vivo measurements were not fully completed because of the difficulty involved in modeling a post-surgical brain and a thermal neutron shield. The experimental simulation technique using the realistic phantom is a useful tool for more reliable dose planning for the intraoperative BNCT.

Journal Articles

Comparison of patient brain dose measurements and the JCDS calculation

Yamamoto, Tetsuya*; Matsumura, Akira*; Yamamoto, Kazuyoshi; Kumada, Hiroaki; Torii, Yoshiya; Endo, Kiyoshi*; Matsushita, Akira*; Shibata, Yasushi*; Nose, Tadao*

Research and Development in Neutron Capture Therapy, p.415 - 418, 2002/09

Dose measurements in a patient's brain undergoing intraoperative BNCT (IOBNCT) were compared with calculations by a JAERI computational dosimetry system (JCDS). The maximum thermal neutron flux on the brain surface from the postirradiation measurement averaged 2.33$$pm$$0.37($$times$$10$$^{9}$$cm$$^{-2}$$s$$^{-1}$$) and the vascular boron dose averaged 11.4$$pm$$1.2 (9.6-12.7) Gy. Using JCDS, the maximum thermal neutron flux in the irradiated volume averaged 2.21$$pm$$0.33($$times$$10$$^{9}$$cm$$^{-2}$$s$$^{-1}$$), while the target vascular dose averaged 5.7 Gy and varied from 3.5 to 7.8 Gy. As such, in the dose planning for intra-operative irradiation, practical use of JCDS is recommended for uniform volume-dose control of postsurgical brain in IOBNCT.

Journal Articles

In-air radiobiological dosimetry of JRR-4 neutron beams for boron neutron capture therapy

Yamamoto, Tetsuya*; Matsumura, Akira*; Yamamoto, Kazuyoshi; Kumada, Hiroaki; Hori, Naohiko; Torii, Yoshiya; Endo, Kiyoshi*; Matsushita, Akira*; Yoshida, Fumiyo*; Shibata, Yasushi*; et al.

Research and Development in Neutron Capture Therapy, p.697 - 700, 2002/09

The RBE of dose components generated in boron neutron capture therapy (BNCT) were separately determined in neutron beams at JRR-4. The cell killing effect of the neutron beam with or without the presence of 10B was highly dependent on the neutron beam used, according to the epithermal and fast neutron content in the beam. RBE (BARBEboron) values of the boron capture reaction for an epithermal (ENB), a mixed thermal-epithermal (TNB-1), and a thermal (TNB-2) neutron beams were 3.99$$pm$$0.24, 3.04$$pm$$0.19 and 1.43$$pm$$0.08, respectively.

JAEA Reports

Development of the fabrication technology for the superconducting coils in the ITER magnet system and its achievements

Hamada, Kazuya; Nakajima, Hideo; Okuno, Kiyoshi; Endo, Sakaru*; Kikuchi, Kenichi*; Kubo, Yoshio*; Aoki, Nobuo*; Yamada, Yuichi*; Osaki, Osamu*; Sasaki, Takashi*; et al.

JAERI-Tech 2002-027, 23 Pages, 2002/03

JAERI-Tech-2002-027.pdf:2.94MB

The Engineering Design Activities (EDA) for the International Thermonuclear Experimental Reactor (ITER) was performed under the collaboration of Japan, EU, Russia and the US. The EDA was successfully completed in July 2001, in which the development of fabrication technology for advanced components, such as superconducting coils, was conducted. The ITER magnet system consists of Toroidal Field coils, a Central Solenoid (CS), Poloidal Field coils and Correction coils. The construction of these coils requires advanced technologies that fairly exceeded those available at the start of the EDA. Therefore, CS Model Coil and TF Model Coil projects were implemented. To fabricate the CS Model Coil, the fabrication technologies for high performance strand, large cable, winding, heat treatment, joint and insulation are indispensable. This report describes the above detailed fabrication technologies successfully developed in the CS Model Coil Project.

Journal Articles

Development and mass production of bronze-processed Nb$$_{3}$$Sn strand with low AC loss and high critical-current density for the ITER

Endo, Sakaru*; *; *; *; *; *; *; Nishi, Masataka; Isono, Takaaki; Nunoya, Yoshihiko; et al.

Teion Kogaku, 32(4), p.158 - 166, 1997/00

no abstracts in English

30 (Records 1-20 displayed on this page)