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Yoneda, Yasuhiro; Kobayashi, Toru; Tsuji, Takuya; Matsumura, Daiju; Saito, Yuji; Noguchi, Yuji*
Japanese Journal of Applied Physics, 62(SM), p.SM1006_1 - SM1006_8, 2023/11
In niobium-based perovskite oxides(NbO), the alkali metal occupying the site is considered to be highly ionic, and therefore, changes in ion size are generally thought to control the phase transition. Since the change in ion size alters the chemical bonding state, we considered it necessary to understand the electronic structure in conjunction with the structure. Therefore, we analyzed the local structure of Nb-based perovskite oxide ferroelectrics NaNbO, KNbO, and AgNbO and compared it with the electronic structure of oxygen using spectroscopic techniques to reveal the chemical bonding state, and observed the electronic structure as varied as the local structure.
Tsuji, Takuya; Matsumura, Daiju; Kobayashi, Toru
SPring-8/SACLA Riyo Kenkyu Seikashu (Internet), 11(4), p.214 - 217, 2023/08
no abstracts in English
Ouchi, Kazuki; Matsumura, Daiju; Tsuji, Takuya; Kobayashi, Toru; Otobe, Haruyoshi; Kitatsuji, Yoshihiro
RSC Advances (Internet), 13(24), p.16321 - 16326, 2023/05
Times Cited Count:0 Percentile:0.00(Chemistry, Multidisciplinary)We clarified the chemical state transformation of deposits following the reduction of uranyl ion (UO) from the results of electrochemical quartz crystal microbalance, impedance spectra and X-ray absorption fine structure measurements. We propose the following deposition mechanism: (1) U is formed by the disproportionation of U. (2) U forms U hydroxide deposits, and (3) finally, the hydroxide deposits transform into U oxide, generally having a larger electrical resistance than the former.
Tsuji, Takuya; Matsumura, Daiju; Kobayashi, Toru; Yaita, Tsuyoshi
SPring-8/SACLA Riyo Kenkyu Seikashu (Internet), 11(1), p.15 - 18, 2023/02
no abstracts in English
Yoshioka, Satoru*; Tsuruta, Konosuke*; Yamamoto, Tomokazu*; Yasuda, Kazuhiro*; Matsumura, Sho*; Sugiyama, Takeharu*; Oba, Yojiro; Ishikawa, Norito; Kobayashi, Eiichi*; Okudaira, Koji*
Journal of the American Ceramic Society, 103(8), p.4654 - 4663, 2020/08
Times Cited Count:4 Percentile:21.78(Materials Science, Ceramics)X-ray absorption near edge structure (XANES) and small-angle X-ray scattering (SAXS) reveal the damaged structures in MgAlO spinel induced by swift heavy ions. SAXS indicates the formation of ion tracks with cylindrical shape with a diameter of 5 nm. XANES indicates the cationic disordering between tetrahedral and octahedral sites by the irradiation. Quantitative analysis of XANES also reveals that cations preferably occupy the octahedral sites at high fluence.
Sugiura, Yuki; Tomura, Tsutomu*; Ishidera, Takamitsu; Doi, Reisuke; Francisco, P. C. M.; Shiwaku, Hideaki; Kobayashi, Toru; Matsumura, Daiju; Takahashi, Yoshio*; Tachi, Yukio
Journal of Radioanalytical and Nuclear Chemistry, 324(2), p.615 - 622, 2020/05
Times Cited Count:4 Percentile:43.68(Chemistry, Analytical)Suzuki, Tomoya*; Narita, Hirokazu*; Ogata, Takeshi*; Suzuki, Hideya; Matsumura, Tatsuro; Kobayashi, Toru; Shiwaku, Hideaki; Yaita, Tsuyoshi
Solvent Extraction Research and Development, Japan, 26(1), p.11 - 19, 2019/06
Times Cited Count:3 Percentile:13.55(Chemistry, Multidisciplinary)The ability of AMP03, a styrene-divinylbenzene copolymer functionalized with -trimethylglycine moieties, to adsorb Pd(II) from HNO solutions was investigated to elucidate the affinity of -trimethylglycine for Pd(II). In the present study, we investigated the mechanism of Pd(II) adsorption by AMP03 by means of adsorption experiments, Fourier Transform Infrared (FT-IR) spectroscopy, and Extended X-ray Absorption Fine Structure (EXAFS) spectroscopy.
Kato, Masaru*; Muto, Marika*; Matsubara, Naohiro*; Uemura, Yohei*; Wakisaka, Yuki*; Yoneuchi, Tsubasa*; Matsumura, Daiju; Ishibara, Tomoko*; Tokushima, Takashi*; Noro, Shinichiro*; et al.
ACS Applied Energy Materials (Internet), 1(5), p.2358 - 2364, 2018/05
Times Cited Count:13 Percentile:45.18(Chemistry, Physical)Yoshioka, Satoru*; Tsuruta, Konosuke*; Yamamoto, Tomokazu*; Yasuda, Kazuhiro*; Matsumura, Sho*; Ishikawa, Norito; Kobayashi, Eiichi*
Physical Chemistry Chemical Physics, 20(7), p.4962 - 4969, 2018/02
Times Cited Count:5 Percentile:22.57(Chemistry, Physical)Cationic disorder in the MgAlO spinel induced by swift heavy ions was investigated using the X-ray absorption near edge structure. With changes in the irradiation fluences of 200 MeV Xe ions, the Mg K-edge and Al K-edge spectra were synchronously changed. The calculated spectra based on density function theory indicate that the change in the experimental spectra was due to cationic disorder between Mg in tetrahedral sites and Al in octahedral sites. These results suggest a high inversion degree to an extent that the completely random configuration is achieved in MgAlO induced by the high density electronic excitation under swift heavy ion irradiation.
Yoshigoe, Akitaka; Shiwaku, Hideaki; Kobayashi, Toru; Shimoyama, Iwao; Matsumura, Daiju; Tsuji, Takuya; Nishihata, Yasuo; Kogure, Toshihiro*; Okochi, Takuo*; Yasui, Akira*; et al.
Applied Physics Letters, 112(2), p.021603_1 - 021603_5, 2018/01
Times Cited Count:6 Percentile:29.42(Physics, Applied)A synchrotron radiation photoemission electron microscope (SR-PEEM) was applied to demonstrate pinpoint analysis of micrometer-sized weathered biotite clay particles with artificially adsorbed cesium (Cs) atoms. Despite the insulating properties of the clay, we observed the spatial distributions of constituent elements (Si, Al, Cs, Mg, Fe) without charging issues. We found that Cs atoms were likely to be adsorbed evenly over the entire particle. Spatially-resolved X-ray absorption spectra (XAS) of the Cs M-edge region showed Cs to be present in a monocation state (Cs). Further pinpoint XAS measurements were also performed at the Fe L-edge to determine the chemical valence of the Fe atoms. Our results demonstrate the utility of SR-PEEM as a tool for spatially-resolved chemical analyses of various environmental substances, which is not limited by the poor conductivity of samples.
Tsuji, Takuya; Matsumura, Daiju; Kobayashi, Toru; Suzuki, Shinichi; Yoshii, Kenji; Nishihata, Yasuo; Yaita, Tsuyoshi
Clay Science, 18(4), p.93 - 97, 2014/12
Matsumura, Daiju; Kobayashi, Toru; Miyazaki, Yuji; Okajima, Yuka*; Nishihata, Yasuo; Yaita, Tsuyoshi
Clay Science, 18(4), p.99 - 105, 2014/12
Yaita, Tsuyoshi; Kobayashi, Toru; Ikeda, Takashi; Matsumura, Daiju; Machida, Masahiko; Okumura, Masahiko; Nakamura, Hiroki
Hoshako, 27(6), p.315 - 322, 2014/11
no abstracts in English
Matsumura, Takeshi*; Michimura, Shinji*; Inami, Toshiya; Otsubo, Toru*; Tanida, Hiroshi*; Iga, Fumitoshi*; Sera, Masafumi*
JPS Conference Proceedings (Internet), 3, p.014008_1 - 014008_6, 2014/06
We study the -type antiferro-octupole (AFO) ordered state of CeLaB below 1.5 K by resonant X-ray diffraction in magnetic fields. Multipole moments induced by the field in the AFO phase are identified. In a mean-field model for the AFO order within the quartet crystal-field ground state, the and antiferroquadrupoles (AFQ) are expected as mostly induced AFQ. However, in contrast to this expectation, the main induced moment is found to be the -type AFQ.
Matsumura, Takeshi*; Michimura, Shinji*; Inami, Toshiya; Otsubo, Toru*; Tanida, Hiroshi*; Iga, Fumitoshi*; Sera, Masafumi*
Physical Review B, 89(1), p.014422_1 - 014422_13, 2014/01
Times Cited Count:14 Percentile:51.90(Materials Science, Multidisciplinary)The multipole ordered phase in CeLaB (phase IV) has been studied by resonant X-ray diffraction in magnetic fields. By utilizing diamond X-ray phase plates to rotate the incident linear polarization and a conventional crystal analyzer system, full linear polarization analysis has been performed to identify the order parameters. The analysis shows that the quadrupoles are more induced by the field than the quadrupoles in phase IV, in disagreement with mean-field calculations, in which the quadrupole is the main induced moment. Hence, we consider that large fluctuations of the quadrupole is hidden behind the primary ordering of the octupole.
Shimizu, Noriko*; Sugiyama, Shigeru*; Maruyama, Mihoko*; Takahashi, Yoshinori*; Adachi, Motoyasu; Tamada, Taro; Hidaka, Koshi*; Hayashi, Yoshio*; Kimura, Toru*; Kiso, Yoshiaki*; et al.
Crystal Growth & Design, 10(7), p.2990 - 2994, 2010/06
Times Cited Count:11 Percentile:71.91(Chemistry, Multidisciplinary)We report crystal growth of human immunodeficiency virus 1 protease (HIV PR) in a complex with its inhibitor KNI-272 by six different methods. Comparative analysis indicates that top-seeded solution growth (TSSG) and TSSG combined with the floating and stirring technique (TSSG-FAST) are efficient strategies for rapidly obtaining large single crystals and effectively preventing polycrystallization of the seed crystal. Neutron diffraction analysis confirmed that the crystalobtained by TSSG is a high-quality single crystal. Furthermore, crystal shape was observed to be influenced by solution flow, suggesting that the degree of supersaturation significantly affects the crystal growth direction of HIV PR complex. This finding implies that the shape of the HIV PR complex crystal might be controlled by the solution flow rate.
Adachi, Motoyasu; Ohara, Takashi; Kurihara, Kazuo; Tamada, Taro; Honjo, Eijiro; Okazaki, Nobuo; Arai, Shigeki; Shoyama, Yoshinari; Kimura, Kaname*; Matsumura, Hiroyoshi*; et al.
Proceedings of the National Academy of Sciences of the United States of America, 106(12), p.4641 - 4646, 2009/03
Times Cited Count:111 Percentile:90.58(Multidisciplinary Sciences)To further understand the catalytic mechanism and inhibitor recognition of HIV-1 protease, we need to determine the locations of key hydrogen atoms in the catalytic aspartates Asp25 and Asp125. The structure of HIV-1 protease in complex with transition-state analog KNI-272 was determined by combined neutron crystallography at 1.9 resolution and X-ray crystallography at 1.4 resolution. The resulting structural data shows that the catalytic residue Asp25 is protonated and that Asp125 is deprotonated. The proton on Asp25 makes a hydrogen bond with the carbonyl group of the allophenylnorstatine group in KNI-272. The deprotonated Asp125 bonds to the hydroxyl proton of Apns. The results provide direct experimental evidence for proposed aspects of the catalytic mechanism of HIV-1 protease; and can therefore contribute substantially to the development of specific inhibitors for therapeutic application.
Matsumura, Hiroyoshi*; Adachi, Motoyasu; Sugiyama, Shigeru*; Okada, Shino*; Yamakami, Megumi*; Tamada, Taro; Hidaka, Koshi*; Hayashi, Yoshio*; Kimura, Toru*; Kiso, Yoshiaki*; et al.
Acta Crystallographica Section F, 64(11), p.1003 - 1006, 2008/11
Times Cited Count:17 Percentile:77.78(Biochemical Research Methods)This paper reports the crystallization and preliminary neutron diffraction measurements of HIV-1 protease, a potential target for anti-HIV therapy, complexed with an inhibitor (KNI-272). The aim of this neutron diffraction study is to obtain structural information about the H atoms and to determine the protonation states of the residues within the active site. The crystal was grown to a size of 1.4 mm by repeated macroseeding and a slow-cooling method using a two-liquid system. Neutron diffraction data were collected at room temperature using a BIX-4 diffractometer at the JRR-3 research reactor of the Japan Atomic Energy Agency (JAEA). The data set was integrated and scaled to 2.3 resolution in space group P2(1)2(1)2, with unit-cell parameters a = 59.5, b = 87.4, c = 46.8 .
Kobune, Masafumi*; Fukushima, Koji*; Yamaji, Toru*; Tada, Hideto*; Yazawa, Tetsuo*; Fujisawa, Hironori*; Shimizu, Masaru*; Nishihata, Yasuo; Matsumura, Daiju; Mizuki, Junichiro; et al.
Journal of Applied Physics, 101(7), p.074110_1 - 074110_6, 2007/04
Times Cited Count:8 Percentile:33.16(Physics, Applied)no abstracts in English
Ishikawa, Masayori*; Ono, Koji*; Matsumura, Akira*; Yamamoto, Tetsuya*; Hiratsuka, Junichi*; Miyatake, Shinichi*; Kato, Itsuro*; Sakurai, Yoshinori*; Kobayashi, Toru*; Kumada, Hiroaki; et al.
Proceedings of 12th International Congress on Neutron Capture Therapy (ICNCT-12), p.397 - 400, 2006/10
An ultraminiature thermal neutron monitor which was named SOF detector (Scintillator with Optical Fiber detector) had been developed for BNCT treatment. We had been experienced 15 clinical trials using SOF detector until the end of 2005, some measurements got good results, and some got unacceptable results. One reason of the unacceptable results was due to dislocation of the detector during treatment. This is because it is difficult to fix the SOF detector on patient's skin without strong sticker. To overcome this problem, a loop-type SOF probe was developed. By using the loop-type SOF detector, fixing on the patient's skin was much easier.