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Maeda, Masaki*; Tanabe, Tadao*; Nishiwaki, Tomoya*; Aoki, Takayuki*; Dozaki, Koji*; Nishimura, Koshiro*; Fujii, Sho*; Ueno, Fumiyoshi; Tanaka, Akio*; Suzuki, Yusuke*; et al.
Transactions of the 27th International Conference on Structural Mechanics in Reactor Technology (SMiRT 27) (Internet), 10 Pages, 2024/03
Nishinaka, Ichiro; Yokoyama, Akihiko*; Washiyama, Koshin*; Maeda, Eita*; Watanabe, Shigeki; Hashimoto, Kazuyuki; Ishioka, Noriko; Makii, Hiroyuki; Toyoshima, Atsushi; Yamada, Norihiro*; et al.
Journal of Radioanalytical and Nuclear Chemistry, 304(3), p.1077 - 1083, 2015/06
Times Cited Count:10 Percentile:61.82(Chemistry, Analytical)Production cross sections of astatine isotopes At in the 29-57 MeV
Li induced reaction with
Pb target have been measured by
- and
-ray spectrometry. Excitation functions of production cross sections have been compared with a statistical model calculation to study the reaction mechanism of
Li +
Pb. Considerably small experimental cross sections of
At and
At compared with the calculation were clearly observed at incident energies higher than 44 MeV, indicating that the effects of breakup reaction play a role. A chemical separation of astatine from an irradiated lead target has been studied with a dry-distillation method. A complementary way to produce astatine isotopes has been developed.
Maeda, Eita*; Yokoyama, Akihiko*; Taniguchi, Takumi*; Washiyama, Koshin*; Nishinaka, Ichiro
Journal of Radioanalytical and Nuclear Chemistry, 303(2), p.1465 - 1468, 2015/02
Times Cited Count:11 Percentile:64.94(Chemistry, Analytical)The At isotope has gathered attention as a promising
-emitter for radionuclide therapy. We report the dependence of the distribution ratio of astatine on the concentration of HCl, and on the polarity of the organic solvent. The results will be useful for development of the
Rn-
At generator.
Fukushi, Keisuke*; Hasegawa, Yusuke*; Maeda, Koshi*; Aoi, Yusuke*; Tamura, Akihiro*; Arai, Shoji*; Yamamoto, Yuhei*; Aosai, Daisuke*; Mizuno, Takashi
Environmental Science & Technology, 47(22), p.12811 - 12818, 2013/11
Times Cited Count:31 Percentile:62.18(Engineering, Environmental)Eu(III) sorption on granite was examined by the combined microscopic and macroscopic approaches. Polished thin sections of the granite were reacted with solutions containing 10 M of Eu(III) and analyzed using EPMA and LA-ICP-MS. The Eu enrichment up to 6 wt.% was observed on most of the biotite grains. The Eu-enriched parts commonly lose K, which is the interlayer cation of biotite, indicating that the sorption mode is cation exchange in the interlayer. Batch Eu(III) sorption experiments on granite and biotite powders were conducted. The macroscopic sorption behavior of biotite was consistent with that of granite. The obtained sorption edges can be reproduced reasonably by the modeling considering single-site cation exchange reactions. Granite is complex mineral assemblages. However, the combined microscopic and macroscopic approaches revealed that elementary reactions by single phase can be representative for the bulk sorption reaction in complex mineral assemblages.
Honjo, Eijiro; Tamada, Taro; Maeda, Yoshitake*; Koshiba, Takumi*; Matsukura, Yasuko*; Okamoto, Tomoyuki*; Ishibashi, Matsujiro*; Tokunaga, Masao*; Kuroki, Ryota
Acta Crystallographica Section F, 61(8), p.788 - 790, 2005/08
Times Cited Count:7 Percentile:54.82(Biochemical Research Methods)Granulocyte colony-stimulating factor (GCSF) receptor receives signals for regulating the proliferation and differentiation of the precursor cells of granulocytes. The complex composed of two GCSFs and two GCSF receptors was crystallized. The crystal of the complex was grown in 1.0 M sodium formate and 0.1 M sodium acetate (pH4.6). It belongs to the space group 4
2
2 (or its enantiomorph
4
2
2) with unit cell dimensions of
=
= 110.1
,
= 331.8
. However, the diffraction data from the crystal beyond 5
resolution could not be collected. Since the heterogeneity of GCSF receptor seems to interrupt growth of good quality crystals, the GCSF receptor was fractionated by achromatography. Crystals of GCSF/fractionated GCSF receptor complex were grown as a new crystal form in 0.2 M ammonium phosphate. The new crystal diffracts beyond 3.0
resolution and belongs to space group
3
21 (or its enantiomorph
3
21) with unit-cell parameters
=
= 134.8,
= 105.7
.
Terasaki, Hidenori*; Kato, Takumi*; Urakawa, Satoru*; Funakoshi, Kenichi*; Suzuki, Akio*; Okada, Taku; Maeda, Makoto*; Sato, Jin*; Kubo, Tomoaki*; Kasai, Shizu*
Earth and Planetary Science Letters, 190(1-2), p.93 - 101, 2001/07
Times Cited Count:54 Percentile:68.95(Geochemistry & Geophysics)The Fe-FeS melt is thought to be the major candidate of the outer core material. Its viscosity is one of the most important physical properties to study the dynamics of the convection in the outer core. We performed the in situ viscosity measurement of the Fe-FeS melt under high pressure using X-ray radiography falling sphere method with a novel sample assembly. Viscosity was measures in the temperature, pressure, and compositional conditions of 1233-1923 K, 1.5-6.9 GPa, and Fe-Fe S
(wt %), respectively. The viscosity coefficients obtained by 17 measurements change systematically in the range of 0.008-0.036 Pa s. An activation energy of the viscous flow, 30 kJ/mol, and the activation volume, 1.5 cm
/mol, are determined as the temperature and pressure dependence, and the viscosity of the Fe
S
melt is found to be smaller than that of the Fe melt by 15 %. These tendencies can be well correlated with the structural variation of the Fe-FeS melt.
Nishinaka, Ichiro; Yokoyama, Akihiko*; Washiyama, Koshin*; Amano, Ryohei*; Ri, Keiko*; Yamada, Norihiro*; Ishiguro, Rika*; Maeda, Eita*; Makii, Hiroyuki; Hashimoto, Kazuyuki; et al.
no journal, ,
We have started to study production and utilization of an radioactive nuclide
At which is a prospective candidate for targeted alpha radiotherapy. We determined production cross sections of astatine radioisotopes in the reaction of 29-48 MeV
Li+
Pb by
-ray and
-ray spectrometry at the tandem accelerator of JAEA-Tokai. Besides, we developed a simple dry-chemical method for separation of astatine.
Hasegawa, Yusuke*; Fukushi, Keisuke*; Maeda, Koshi*; Yamamoto, Yuhei; Aosai, Daisuke; Mizuno, Takashi
no journal, ,
Maeda, Koshi*; Fukushi, Keisuke*; Hasegawa, Yusuke*; Yamamoto, Yuhei; Aosai, Daisuke; Mizuno, Takashi
no journal, ,
Maeda, Koshi*; Fukushi, Keisuke*; Hasegawa, Yusuke*; Yamamoto, Yuhei; Aosai, Daisuke; Mizuno, Takashi
no journal, ,
no abstracts in English
Hasegawa, Yusuke*; Fukushi, Keisuke*; Maeda, Koshi*; Yamamoto, Yuhei; Aosai, Daisuke; Mizuno, Takashi
no journal, ,
no abstracts in English
Nishinaka, Ichiro; Yokoyama, Akihiko*; Washiyama, Koshin*; Amano, Ryohei*; Maeda, Eita*; Yamada, Norihiro*; Makii, Hiroyuki; Watanabe, Shigeki; Ishioka, Noriko; Hashimoto, Kazuyuki
no journal, ,
Nishinaka, Ichiro; Makii, Hiroyuki; Toyoshima, Atsushi; Yokoyama, Akihiko*; Washiyama, Koshin*; Amano, Ryohei*; Maeda, Eita*; Yamada, Norihiro*; Taniguchi, Takumi*; Watanabe, Shigeki; et al.
no journal, ,
no abstracts in English
Nishinaka, Ichiro; Yokoyama, Akihiko*; Washiyama, Koshin*; Amano, Ryohei*; Maeda, Eita*; Yamada, Norihiro*; Makii, Hiroyuki; Toyoshima, Atsushi; Watanabe, Shigeki; Ishioka, Noriko; et al.
no journal, ,
Production cross sections of astatine in 29-57 MeV Li +
Pb have been measured by
- and
-ray spectrometry. Excitation functions of production cross sections have been compared with a statistical model calculation to study the reaction mechanism of the
Li +
Pb reaction. It indicates that the breakup of
Li plays a rule in the
Li +
Pb reaction. Besides, we have developed a dry-distillation method which separates carrier-free astatine from an irradiated lead target.
Nishinaka, Ichiro; Yokoyama, Akihiko*; Washiyama, Koshin*; Amano, Ryohei*; Maeda, Eita*; Yamada, Norihiro*; Makii, Hiroyuki; Toyoshima, Atsushi; Watanabe, Shigeki; Ishioka, Noriko; et al.
no journal, ,
To promote utilization of a radioactive nuclide At which draws increasing attention as a promissing
-emitter for targeted alpha therapy, we have measured production cross sections of astatine isotopes in the 29-57 MeV
Li+
Pb reaction using the tandem accelerator of JAEA-Tokai, providing nuclear data for production. For pharmaceutical study and so on, beside, we have developed a new separation procedure based on a dry-distillation method which separates carrier free astatine isotopes from lead targets with high radiochemical and chemical purity and high yields.
Yamamoto, Yuhei; Aosai, Daisuke; Mizuno, Takashi; Fukushi, Keisuke*; Hasegawa, Yusuke*; Maeda, Koshi*
no journal, ,
no abstracts in English
Maeda, Koshi*; Hasegawa, Yusuke*; Fukushi, Keisuke*; Yamamoto, Yuhei; Aosai, Daisuke; Mizuno, Takashi
no journal, ,
no abstracts in English
Nishinaka, Ichiro; Yokoyama, Akihiko*; Washiyama, Koshin*; Amano, Ryohei*; Maeda, Eita*; Taniguchi, Takumi*; Murakami, Kento*; Watanabe, Shigeki; Suzuki, Hiroyuki; Ishioka, Noriko; et al.
no journal, ,
In general, an -emitter
At which is a prospective candidate for utilization in targeted alpha radiotherapy is produced through the
Bi(
He, 2n)
At reaction. In contrast, our project is focusing on the production in the
Bi(
Li, 5n)
Rn reaction. This enables us to supply
At in a
Rn/
At generator system. The daughter
At (7.2 h half-life) is extracted from the parent
Rn (14h), expanding time-frame for transportation and use of
At. To use astatine and iodine radioisotopes in our project, the excitation functions of
Bi(
Li, xn)
Rn,
Pb(
Li, xn)
At and
Sn(
Li, xn)
I reactions have been measured. In addition to that, separation techniques have been developed. We report not only on the production and separation of astatine and iodine radioisotopes in the reactions but also on the utilization of those radioisotopes.
Washiyama, Koshin*; Maeda, Eita*; Yokoyama, Akihiko*; Nishinaka, Ichiro; Taniguchi, Takumi*; Yamada, Norihiro*; Makii, Hiroyuki; Toyoshima, Atsushi; Amano, Ryohei*
no journal, ,
A Rn/
At generator for targeted alpha therapy has been developed.
Hasegawa, Yusuke*; Yamamoto, Yuhei; Aosai, Daisuke; Mizuno, Takashi; Maeda, Koshi*; Fukushi, Keisuke*
no journal, ,
no abstracts in English