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Iwata T, Kousa T, Nishioka Y, Ohwada K, Sumida K, Annese E, Kakoki M, Kuroda K, Iwasawa H, Arita M, Kumar S, Kimura A, Miyamoto K, Okuda T. Laser-based angle-resolved photoemission spectroscopy with micrometer spatial resolution and detection of three-dimensional spin vector. Sci Rep 2024; 14:127. [PMID: 38177136 PMCID: PMC10766951 DOI: 10.1038/s41598-023-47719-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Accepted: 11/17/2023] [Indexed: 01/06/2024] Open
Abstract
We have developed a state-of-the-art apparatus for laser-based spin- and angle-resolved photoemission spectroscopy with micrometer spatial resolution (µ-SARPES). This equipment is realized by the combination of a high-resolution photoelectron spectrometer, a 6 eV laser with high photon flux that is focused down to a few micrometers, a high-precision sample stage control system, and a double very-low-energy-electron-diffraction spin detector. The setup achieves an energy resolution of 1.5 (5.5) meV without (with) the spin detection mode, compatible with a spatial resolution better than 10 µm. This enables us to probe both spatially-resolved electronic structures and vector information of spin polarization in three dimensions. The performance of µ-SARPES apparatus is demonstrated by presenting ARPES and SARPES results from topological insulators and Au photolithography patterns on a Si (001) substrate.
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Affiliation(s)
- Takuma Iwata
- Graduate School of Advanced Science and Engineering, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, 739-8526, Japan
- International Institute for Sustainability with Knotted Chiral Meta Matter (WPI-SKCM2), Hiroshima University, Higashi-hiroshima, 739-8526, Japan
| | - T Kousa
- Graduate School of Advanced Science and Engineering, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, 739-8526, Japan
| | - Y Nishioka
- Graduate School of Advanced Science and Engineering, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, 739-8526, Japan
| | - K Ohwada
- Graduate School of Advanced Science and Engineering, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, 739-8526, Japan
| | - K Sumida
- Materials Sciences Research Center, Japan Atomic Energy Agency, Sayo-gun, Hyogo, 679-5148, Japan
- Hiroshima Synchrotron Radiation Center, Hiroshima University, 2-313 Kagamiyama, Higashi-Hiroshima, 739-0046, Japan
| | - E Annese
- Brazilian Center for Research in Physics, Rua Dr. Xavier Sigaud 150, Rio de Janeiro, RJ, 22290-180, Brazil
| | - M Kakoki
- Graduate School of Advanced Science and Engineering, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, 739-8526, Japan
| | - Kenta Kuroda
- Graduate School of Advanced Science and Engineering, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, 739-8526, Japan.
- International Institute for Sustainability with Knotted Chiral Meta Matter (WPI-SKCM2), Hiroshima University, Higashi-hiroshima, 739-8526, Japan.
| | - H Iwasawa
- Institute for Advanced Synchrotron Light Source, National Institutes for Quantum Science and Technology, Sendai, 980-8579, Japan
- Synchrotron Radiation Research Center, National Institutes for Quantum Science and Technology, Hyogo, 679-5148, Japan
- Hiroshima Synchrotron Radiation Center, Hiroshima University, 2-313 Kagamiyama, Higashi-Hiroshima, 739-0046, Japan
| | - M Arita
- Hiroshima Synchrotron Radiation Center, Hiroshima University, 2-313 Kagamiyama, Higashi-Hiroshima, 739-0046, Japan
| | - S Kumar
- Hiroshima Synchrotron Radiation Center, Hiroshima University, 2-313 Kagamiyama, Higashi-Hiroshima, 739-0046, Japan
| | - A Kimura
- Graduate School of Advanced Science and Engineering, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, 739-8526, Japan
- International Institute for Sustainability with Knotted Chiral Meta Matter (WPI-SKCM2), Hiroshima University, Higashi-hiroshima, 739-8526, Japan
| | - K Miyamoto
- Hiroshima Synchrotron Radiation Center, Hiroshima University, 2-313 Kagamiyama, Higashi-Hiroshima, 739-0046, Japan
| | - T Okuda
- Hiroshima Synchrotron Radiation Center, Hiroshima University, 2-313 Kagamiyama, Higashi-Hiroshima, 739-0046, Japan
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2
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Suzuki N, Ikeda Y, Oomori G, Yamada S, Okuda T, Minami S. Gastrointestinal: Type 2 autoimmune pancreatitis diagnosed with endoscopic ultrasound-guided fine needle biopsy. J Gastroenterol Hepatol 2023. [PMID: 38159080 DOI: 10.1111/jgh.16459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Accepted: 12/11/2023] [Indexed: 01/03/2024]
Affiliation(s)
- N Suzuki
- Department of Gastroenterology, Oji General Hospital, Tomakomai, Hokkaido, Japan
| | - Y Ikeda
- Department of Gastroenterology, Oji General Hospital, Tomakomai, Hokkaido, Japan
| | - G Oomori
- Department of Gastroenterology, Oji General Hospital, Tomakomai, Hokkaido, Japan
| | - S Yamada
- Department of Gastroenterology, Oji General Hospital, Tomakomai, Hokkaido, Japan
| | - T Okuda
- Department of Gastroenterology, Oji General Hospital, Tomakomai, Hokkaido, Japan
| | - S Minami
- Department of Gastroenterology, Oji General Hospital, Tomakomai, Hokkaido, Japan
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Abstract
During the COVID-19 pandemic, it has been important to both minimize the risk of infection and restore daily life. As a typical example, mass gathering events, such as sporting events, are gradually becoming more common, thanks to the measures taken to contain COVID-19. Some pilot studies have been launched at governments' initiative to investigate the risk of infection without measures such as face masks and physical distancing at mass gathering events, but the ethics of these studies should be carefully considered. On the other hand, it is still beneficial to implement infection control measures at mass gathering events and, in parallel, to estimate the risk of infection with measures in place, especially under a lack of vaccination progress or the spread of mutant strains possibly resistant to vaccines. To help improve compliance with measures taken by spectators and organizers and to ensure their effectiveness, we have conducted quantitative evaluations of the implementation of such measures by monitoring CO2 concentrations, assessing the proportion of people wearing face masks and analysing human flow at the event. This approach allows us to share our observations with stakeholders and participants, enabling us to protect the culture of mass gathering events, minimize the risk of infection and restore a sense of well-being in daily life.
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Affiliation(s)
- M Murakami
- Department of Health Risk Communication, Fukushima Medical University School of Medicine, 1 Hikarigaoka, Fukushima, Fukushima 960-1295, Japan
| | - T Yasutaka
- Institute for Geo-Resources and Environment, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1, Higashi, Tsukuba, Ibaraki 305-8567, Japan
| | - M Onishi
- Artificial Intelligence Research Center, National Institute of Advanced Industrial Science and Technology (AIST), 2-4-7 Aomi, Koto-ku, Tokyo 135-0064, Japan
| | - W Naito
- Research Institute of Science for Safety and Sustainability, National Institute of Advanced Industrial Science and Technology (AIST), 16-1, Onogawa, Tsukuba, Ibaraki 305-8569, Japan
| | - N Shinohara
- Research Institute of Science for Safety and Sustainability, National Institute of Advanced Industrial Science and Technology (AIST), 16-1, Onogawa, Tsukuba, Ibaraki 305-8569, Japan
| | - T Okuda
- Department of Applied Chemistry, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku, Yokohama, Kanagawa 223-8522, Japan
| | - K Fujii
- R&D-Hygiene Science Research Center, Kao Corporation, 2-1-3, Bunka, Sumida-ku, Tokyo 131-8501, Japan
| | - K Katayama
- Laboratory of Sequence Analysis, Human Genome Center, The Institute of Medical Science, The University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639, Japan
| | - S Imoto
- Division of Health Medical Intelligence, Human Genome Center, The Institute of Medical Science, The University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639, Japan
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Okuda T, Nishimura Y, Nishioka K, Kishimoto S, Kikuchi Y, Nakamura T. A 5-kV pulse generator with a 100-kV/µs slew rate based on series-connected 1700-V SiC MOSFETs for electrical insulation tests. Rev Sci Instrum 2021; 92:114705. [PMID: 34852512 DOI: 10.1063/5.0058083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Accepted: 10/20/2021] [Indexed: 06/13/2023]
Abstract
This study demonstrates a high-slew-rate 5-kV pulse generator for electrical insulation tests. Electrical equipment, such as electrical actuators and traction drive motors, are exposed to severe electrical stress because recent switching inverters have high-frequency outputs with high supply voltages using wide-bandgap power devices. For an advanced electrical insulation test, a high-voltage pulse generator is required with a high slew rate; however, such generators suffer from large switching noise, followed by measurement noise, such as ground voltage fluctuations and radiation noise, hindering the detection of partial discharge (PD) phenomena. In this study, we propose a 5-kV pulse generator based on series-connected 1700-V silicon carbide (SiC) metal-oxide-semiconductor field-effect transistors (MOSFETs). Four 1700-V SiC MOSFETs are connected in series as a 5-kV SiC switching module, constituting a half-bridge configuration for the pulse generator. The obtained switching waveforms exhibit fast rise times of 48 ns under 5 kV and 6.2 ns under 400 V with a low voltage overshoot and ringing owing to superior device characteristics and reduced parasitic inductances. Because of the low switching noise, we detect a clear PD signal with a 1500-V pulse when using the fabricated pulse generator for a PD test of a twisted pair. The proposed pulse generator uses a hard switching configuration such that the pulse generator can vary the pulse width from 150 ns to DC and increase the switching pulse cycle beyond 1 MHz by changing the control signals of the SiC MOSFETs.
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Affiliation(s)
- T Okuda
- Graduate School of Engineering, Osaka University, Osaka 565-0871, Japan
| | - Y Nishimura
- Graduate School of Engineering, Osaka University, Osaka 565-0871, Japan
| | - K Nishioka
- Graduate School of Engineering, Osaka University, Osaka 565-0871, Japan
| | - S Kishimoto
- Graduate School of Engineering, University of Hyogo, Hyogo 671-2280, Japan
| | - Y Kikuchi
- Graduate School of Engineering, University of Hyogo, Hyogo 671-2280, Japan
| | - T Nakamura
- Graduate School of Engineering, Osaka University, Osaka 565-0871, Japan
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Grenz PJ, Thonig D, Holtmann M, Miyamoto K, Kumar S, Schwier E, Okuda T, Henk J, Donath M. Adlayer influence on Dirac-type surface state at W(110). J Phys Condens Matter 2021; 33:285504. [PMID: 33946058 DOI: 10.1088/1361-648x/abfdf3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Accepted: 05/04/2021] [Indexed: 06/12/2023]
Abstract
In a combined experimental and theoretical study, we investigated how Fe and Co adlayers on W(110) affect the Dirac-type surface state (DSS). Angle-resolved photoelectron spectroscopy data show an increase in binding energy of 75 meV and 107 meV for Fe and Co, respectively. In order to identify the origin of the energy shift we performed first-principles calculations of the surface electronic structure. The inward surface relaxation of the uncovered W(110) surface is lifted by the adlayers. This structural change is one reason of the energy shift of the DSS. Furthermore, the Fe and Co adlayers change the surface potential, which results in an additional energy shift of the DSS.
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Affiliation(s)
- P J Grenz
- Physikalisches Institut, Westfälische Wilhelms-Universität Münster, Wilhelm-Klemm-Straße 10, 48149 Münster, Germany
| | - D Thonig
- Department of Physics and Astronomy, Material Theory, University Uppsala, Box 516, 75120 Uppsala, Sweden
- School of Science and Technology, Örebro University, 701 82 Örebro, Sweden
| | - M Holtmann
- Physikalisches Institut, Westfälische Wilhelms-Universität Münster, Wilhelm-Klemm-Straße 10, 48149 Münster, Germany
| | - K Miyamoto
- Hiroshima Synchrotron Radiation Center, Hiroshima University, 2-313 Kagamiyama, Higashi-Hiroshima 739-0046, Japan
| | - S Kumar
- Hiroshima Synchrotron Radiation Center, Hiroshima University, 2-313 Kagamiyama, Higashi-Hiroshima 739-0046, Japan
| | - E Schwier
- Hiroshima Synchrotron Radiation Center, Hiroshima University, 2-313 Kagamiyama, Higashi-Hiroshima 739-0046, Japan
| | - T Okuda
- Hiroshima Synchrotron Radiation Center, Hiroshima University, 2-313 Kagamiyama, Higashi-Hiroshima 739-0046, Japan
| | - J Henk
- Institute of Physics, Martin Luther University Halle-Wittenberg, 06099 Halle, Saale, Germany
| | - M Donath
- Physikalisches Institut, Westfälische Wilhelms-Universität Münster, Wilhelm-Klemm-Straße 10, 48149 Münster, Germany
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Dai J, Frantzeskakis E, Aryal N, Chen KW, Fortuna F, Rault JE, Le Fèvre P, Balicas L, Miyamoto K, Okuda T, Manousakis E, Baumbach RE, Santander-Syro AF. Experimental Observation and Spin Texture of Dirac Node Arcs in Tetradymite Topological Metals. Phys Rev Lett 2021; 126:196407. [PMID: 34047592 DOI: 10.1103/physrevlett.126.196407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Revised: 03/08/2021] [Accepted: 04/15/2021] [Indexed: 06/12/2023]
Abstract
We report the observation of a nontrivial spin texture in Dirac node arcs, i.e., novel topological objects formed when Dirac cones of massless particles extend along an open one-dimensional line in momentum space. We find that such states are present in all the compounds of the tetradymite M_{2}Te_{2}X family (M=Ti, Zr, or Hf and X=P or As) regardless of the weak or strong character of the topological invariant. The Dirac node arcs in tetradymites are thus the simplest possible textbook example of a type-I Dirac system with a single spin-polarized node arc.
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Affiliation(s)
- J Dai
- Université Paris-Saclay, CNRS, Institut des Sciences Moléculaires d'Orsay, 91405 Orsay, France
| | - E Frantzeskakis
- Université Paris-Saclay, CNRS, Institut des Sciences Moléculaires d'Orsay, 91405 Orsay, France
| | - N Aryal
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32306, USA
- Department of Physics, Florida State University, Tallahassee, Florida 32306, USA
| | - K-W Chen
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32306, USA
- Department of Physics, Florida State University, Tallahassee, Florida 32306, USA
| | - F Fortuna
- Université Paris-Saclay, CNRS, Institut des Sciences Moléculaires d'Orsay, 91405 Orsay, France
| | - J E Rault
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint-Aubin-BP48, 91192 Gif-sur-Yvette, France
| | - P Le Fèvre
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint-Aubin-BP48, 91192 Gif-sur-Yvette, France
| | - L Balicas
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32306, USA
- Department of Physics, Florida State University, Tallahassee, Florida 32306, USA
| | - K Miyamoto
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32306, USA
- Department of Physics, Florida State University, Tallahassee, Florida 32306, USA
| | - T Okuda
- Hiroshima Synchrotron Radiation Center (HSRC), Hiroshima University, 2-313 Kagamiyama, Higashi-Hiroshima 739-0046, Japan
| | - E Manousakis
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32306, USA
- Department of Physics, Florida State University, Tallahassee, Florida 32306, USA
- Department of Physics, National and Kapodistrian University of Athens, Panepistimioupolis, Zografos, 157 84 Athens, Greece
| | - R E Baumbach
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32306, USA
- Department of Physics, Florida State University, Tallahassee, Florida 32306, USA
| | - A F Santander-Syro
- Université Paris-Saclay, CNRS, Institut des Sciences Moléculaires d'Orsay, 91405 Orsay, France
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Ito M, Takase Y, Sasamura K, Kotsuma T, Ooshima Y, Minami Y, Suzuki J, Tanaka E, Oguchi M, Okuda T, Suzuki K, Yoshioka Y. Comparison of Physician-Recorded Toxicities and Patient-Reported Outcomes Among 5 Different Radiotherapy Methods for Prostate Cancer. Int J Radiat Oncol Biol Phys 2020. [DOI: 10.1016/j.ijrobp.2020.07.543] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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8
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Shikin AM, Estyunin DA, Klimovskikh II, Filnov SO, Schwier EF, Kumar S, Miyamoto K, Okuda T, Kimura A, Kuroda K, Yaji K, Shin S, Takeda Y, Saitoh Y, Aliev ZS, Mamedov NT, Amiraslanov IR, Babanly MB, Otrokov MM, Eremeev SV, Chulkov EV. Nature of the Dirac gap modulation and surface magnetic interaction in axion antiferromagnetic topological insulator [Formula: see text]. Sci Rep 2020; 10:13226. [PMID: 32764583 PMCID: PMC7413556 DOI: 10.1038/s41598-020-70089-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Accepted: 07/22/2020] [Indexed: 11/09/2022] Open
Abstract
Modification of the gap at the Dirac point (DP) in axion antiferromagnetic topological insulator [Formula: see text] and its electronic and spin structure have been studied by angle- and spin-resolved photoemission spectroscopy (ARPES) under laser excitation at various temperatures (9-35 K), light polarizations and photon energies. We have distinguished both large (60-70 meV) and reduced ([Formula: see text]) gaps at the DP in the ARPES dispersions, which remain open above the Neél temperature ([Formula: see text]). We propose that the gap above [Formula: see text] remains open due to a short-range magnetic field generated by chiral spin fluctuations. Spin-resolved ARPES, XMCD and circular dichroism ARPES measurements show a surface ferromagnetic ordering for the "large gap" sample and apparently significantly reduced effective magnetic moment for the "reduced gap" sample. These observations can be explained by a shift of the Dirac cone (DC) state localization towards the second Mn layer due to structural disturbance and surface relaxation effects, where DC state is influenced by compensated opposite magnetic moments. As we have shown by means of ab-initio calculations surface structural modification can result in a significant modulation of the DP gap.
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Affiliation(s)
- A. M. Shikin
- Saint Petersburg State University, 198504 Saint Petersburg, Russia
| | - D. A. Estyunin
- Saint Petersburg State University, 198504 Saint Petersburg, Russia
| | | | - S. O. Filnov
- Saint Petersburg State University, 198504 Saint Petersburg, Russia
| | - E. F. Schwier
- Hiroshima Synchrotron Radiation Center, Hiroshima University, Hiroshima, Japan
| | - S. Kumar
- Hiroshima Synchrotron Radiation Center, Hiroshima University, Hiroshima, Japan
| | - K. Miyamoto
- Hiroshima Synchrotron Radiation Center, Hiroshima University, Hiroshima, Japan
| | - T. Okuda
- Hiroshima Synchrotron Radiation Center, Hiroshima University, Hiroshima, Japan
| | - A. Kimura
- Department of Physical Sciences, Graduate School of Science, Hiroshima University, Hiroshima, Japan
| | - K. Kuroda
- ISSP, University of Tokyo, Kashiwa, Chiba 277-8581 Japan
| | - K. Yaji
- ISSP, University of Tokyo, Kashiwa, Chiba 277-8581 Japan
| | - S. Shin
- ISSP, University of Tokyo, Kashiwa, Chiba 277-8581 Japan
| | - Y. Takeda
- Materials Sciences Research Center, Japan Atomic Energy Agency, Sayo, Hyogo 679-5148 Japan
| | - Y. Saitoh
- Materials Sciences Research Center, Japan Atomic Energy Agency, Sayo, Hyogo 679-5148 Japan
| | - Z. S. Aliev
- Azerbaijan State Oil and Industry University, AZ1010 Baku, Azerbaijan
- Institute of Physics, ANAS, AZ1143 Baku, Azerbaijan
| | | | - I. R. Amiraslanov
- Institute of Physics, ANAS, AZ1143 Baku, Azerbaijan
- Baku State University, AZ1148 Baku, Azerbaijan
| | - M. B. Babanly
- Baku State University, AZ1148 Baku, Azerbaijan
- Institute of Catalysis and Inorganic Chemistry, ANAS, AZ1143 Baku, Azerbaijan
| | - M. M. Otrokov
- Centro de Física de Materiales (CFM-MPC), Centro Mixto CSIC-UPV/EHU, 20018 Donostia-San Sebastián, Basque Country Spain
- IKERBASQUE, Basque Foundation for Science, 48011 Bilbao, Basque Country Spain
| | - S. V. Eremeev
- Saint Petersburg State University, 198504 Saint Petersburg, Russia
- Institute of Strength Physics and Materials Science, 634055 Tomsk, Russia
- Tomsk State University, 634050 Tomsk, Russia
| | - E. V. Chulkov
- Saint Petersburg State University, 198504 Saint Petersburg, Russia
- Tomsk State University, 634050 Tomsk, Russia
- Donostia International Physics Center (DIPC), 20018 Donostia-San Sebastián, Basque Country Spain
- Departamento de Física de Materiales, Facultad de Ciencias Químicas, UPV/EHU, Apdo. 1072, 20080 San Sebastián, Spain
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9
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Usachov DY, Nechaev IA, Poelchen G, Güttler M, Krasovskii EE, Schulz S, Generalov A, Kliemt K, Kraiker A, Krellner C, Kummer K, Danzenbächer S, Laubschat C, Weber AP, Sánchez-Barriga J, Chulkov EV, Santander-Syro AF, Imai T, Miyamoto K, Okuda T, Vyalikh DV. Cubic Rashba Effect in the Surface Spin Structure of Rare-Earth Ternary Materials. Phys Rev Lett 2020; 124:237202. [PMID: 32603174 DOI: 10.1103/physrevlett.124.237202] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Revised: 04/13/2020] [Accepted: 05/19/2020] [Indexed: 06/11/2023]
Abstract
Spin-orbit interaction and structure inversion asymmetry in combination with magnetic ordering is a promising route to novel materials with highly mobile spin-polarized carriers at the surface. Spin-resolved measurements of the photoemission current from the Si-terminated surface of the antiferromagnet TbRh_{2}Si_{2} and their analysis within an ab initio one-step theory unveil an unusual triple winding of the electron spin along the fourfold-symmetric constant energy contours of the surface states. A two-band k·p model is presented that yields the triple winding as a cubic Rashba effect. The curious in-plane spin-momentum locking is remarkably robust and remains intact across a paramagnetic-antiferromagnetic transition in spite of spin-orbit interaction on Rh atoms being considerably weaker than the out-of-plane exchange field due to the Tb 4f moments.
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Affiliation(s)
- D Yu Usachov
- St. Petersburg State University, 7/9 Universitetskaya Naberezhnaya, St. Petersburg, 199034, Russia
| | - I A Nechaev
- Department of Electricity and Electronics, FCT-ZTF, UPV-EHU, 48080 Bilbao, Spain
| | - G Poelchen
- Institut für Festkörperphysik und Materialphysik, Technische Universität Dresden, D-01062 Dresden, Germany
| | - M Güttler
- Institut für Festkörperphysik und Materialphysik, Technische Universität Dresden, D-01062 Dresden, Germany
| | - E E Krasovskii
- Donostia International Physics Center (DIPC), 20018 Donostia/San Sebastián, Basque Country, Spain
- Departamento de Física de Materiales UPV/EHU, 20080 Donostia/San Sebastián, Basque Country, Spain
- IKERBASQUE, Basque Foundation for Science, 48013, Bilbao, Spain
| | - S Schulz
- Institut für Festkörperphysik und Materialphysik, Technische Universität Dresden, D-01062 Dresden, Germany
| | - A Generalov
- Max IV Laboratory, Lund University, Box 118, 22100 Lund, Sweden
| | - K Kliemt
- Kristall- und Materiallabor, Physikalisches Institut, Goethe-Universität Frankfurt, Max-von-Laue Strasse 1, D-60438 Frankfurt am Main, Germany
| | - A Kraiker
- Kristall- und Materiallabor, Physikalisches Institut, Goethe-Universität Frankfurt, Max-von-Laue Strasse 1, D-60438 Frankfurt am Main, Germany
| | - C Krellner
- Kristall- und Materiallabor, Physikalisches Institut, Goethe-Universität Frankfurt, Max-von-Laue Strasse 1, D-60438 Frankfurt am Main, Germany
| | - K Kummer
- European Synchrotron Radiation Facility, 71 Avenue des Martyrs, Grenoble, France
| | - S Danzenbächer
- Institut für Festkörperphysik und Materialphysik, Technische Universität Dresden, D-01062 Dresden, Germany
| | - C Laubschat
- Institut für Festkörperphysik und Materialphysik, Technische Universität Dresden, D-01062 Dresden, Germany
| | - A P Weber
- Donostia International Physics Center (DIPC), 20018 Donostia/San Sebastián, Basque Country, Spain
| | - J Sánchez-Barriga
- Helmholtz-Zentrum Berlin für Materialien und Energie, Elektronenspeicherring BESSY II, Albert-Einstein-Strasse 15, D-12489 Berlin, Germany
| | - E V Chulkov
- St. Petersburg State University, 7/9 Universitetskaya Naberezhnaya, St. Petersburg, 199034, Russia
- Donostia International Physics Center (DIPC), 20018 Donostia/San Sebastián, Basque Country, Spain
- Departamento de Física de Materiales UPV/EHU, 20080 Donostia/San Sebastián, Basque Country, Spain
- Centro de Física de Materiales CFM-MPC and Centro Mixto CSIC-UPV/EHU, 20018 Donostia/San Sebastián, Basque Country, Spain
- Tomsk State University, Lenina Avenue 36, 634050, Tomsk, Russia
| | - A F Santander-Syro
- Université Paris-Saclay, CNRS, Institut des Sciences Moléculaires d'Orsay, 91405, Orsay, France
| | - T Imai
- Graduate School of Science, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8526, Japan
| | - K Miyamoto
- Hiroshima Synchrotron Radiation Center, Hiroshima University, 2-313 Kagamiyama, Higashi-Hiroshima 739-0046, Japan
| | - T Okuda
- Hiroshima Synchrotron Radiation Center, Hiroshima University, 2-313 Kagamiyama, Higashi-Hiroshima 739-0046, Japan
| | - D V Vyalikh
- Donostia International Physics Center (DIPC), 20018 Donostia/San Sebastián, Basque Country, Spain
- IKERBASQUE, Basque Foundation for Science, 48013, Bilbao, Spain
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10
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Mitsuishi N, Sugita Y, Bahramy MS, Kamitani M, Sonobe T, Sakano M, Shimojima T, Takahashi H, Sakai H, Horiba K, Kumigashira H, Taguchi K, Miyamoto K, Okuda T, Ishiwata S, Motome Y, Ishizaka K. Switching of band inversion and topological surface states by charge density wave. Nat Commun 2020; 11:2466. [PMID: 32424170 PMCID: PMC7235022 DOI: 10.1038/s41467-020-16290-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Accepted: 04/25/2020] [Indexed: 11/10/2022] Open
Abstract
Topologically nontrivial materials host protected edge states associated with the bulk band inversion through the bulk-edge correspondence. Manipulating such edge states is highly desired for developing new functions and devices practically using their dissipation-less nature and spin-momentum locking. Here we introduce a transition-metal dichalcogenide VTe2, that hosts a charge density wave (CDW) coupled with the band inversion involving V3d and Te5p orbitals. Spin- and angle-resolved photoemission spectroscopy with first-principles calculations reveal the huge anisotropic modification of the bulk electronic structure by the CDW formation, accompanying the selective disappearance of Dirac-type spin-polarized topological surface states that exist in the normal state. Thorough three dimensional investigation of bulk states indicates that the corresponding band inversion at the Brillouin zone boundary dissolves upon the CDW formation, by transforming into anomalous flat bands. Our finding provides a new insight to the topological manipulation of matters by utilizing CDWs' flexible characters to external stimuli.
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Affiliation(s)
- N Mitsuishi
- Department of Applied Physics, The University of Tokyo, Tokyo, 113-8656, Japan
- Quantum-Phase Electronics Center (QPEC), The University of Tokyo, Wako, 113-8656, Japan
| | - Y Sugita
- Department of Applied Physics, The University of Tokyo, Tokyo, 113-8656, Japan
| | - M S Bahramy
- Department of Applied Physics, The University of Tokyo, Tokyo, 113-8656, Japan
- Quantum-Phase Electronics Center (QPEC), The University of Tokyo, Wako, 113-8656, Japan
- RIKEN Center for Emergent Matter Science (CEMS), Wako, 351-0198, Japan
| | - M Kamitani
- Department of Applied Physics, The University of Tokyo, Tokyo, 113-8656, Japan
- Quantum-Phase Electronics Center (QPEC), The University of Tokyo, Wako, 113-8656, Japan
| | - T Sonobe
- Department of Applied Physics, The University of Tokyo, Tokyo, 113-8656, Japan
- Quantum-Phase Electronics Center (QPEC), The University of Tokyo, Wako, 113-8656, Japan
| | - M Sakano
- Department of Applied Physics, The University of Tokyo, Tokyo, 113-8656, Japan
- Quantum-Phase Electronics Center (QPEC), The University of Tokyo, Wako, 113-8656, Japan
| | - T Shimojima
- RIKEN Center for Emergent Matter Science (CEMS), Wako, 351-0198, Japan
| | - H Takahashi
- Division of Materials Physics, Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka, 560-8531, Japan
| | - H Sakai
- Department of Physics, Osaka University, Toyonaka, Osaka, 560-0043, Japan
| | - K Horiba
- Condensed Matter Research Center and Photon Factory, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), Tsukuba, 305-0801, Japan
| | - H Kumigashira
- Condensed Matter Research Center and Photon Factory, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), Tsukuba, 305-0801, Japan
| | - K Taguchi
- Hiroshima Synchrotron Radiation Center (HSRC), Hiroshima University, 2-313 Kagamiyama, Higashi-Hiroshima, 739-0046, Japan
| | - K Miyamoto
- Hiroshima Synchrotron Radiation Center (HSRC), Hiroshima University, 2-313 Kagamiyama, Higashi-Hiroshima, 739-0046, Japan
| | - T Okuda
- Hiroshima Synchrotron Radiation Center (HSRC), Hiroshima University, 2-313 Kagamiyama, Higashi-Hiroshima, 739-0046, Japan
| | - S Ishiwata
- Division of Materials Physics, Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka, 560-8531, Japan
| | - Y Motome
- Department of Applied Physics, The University of Tokyo, Tokyo, 113-8656, Japan
| | - K Ishizaka
- Department of Applied Physics, The University of Tokyo, Tokyo, 113-8656, Japan.
- Quantum-Phase Electronics Center (QPEC), The University of Tokyo, Wako, 113-8656, Japan.
- RIKEN Center for Emergent Matter Science (CEMS), Wako, 351-0198, Japan.
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11
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Sakano M, Hirayama M, Takahashi T, Akebi S, Nakayama M, Kuroda K, Taguchi K, Yoshikawa T, Miyamoto K, Okuda T, Ono K, Kumigashira H, Ideue T, Iwasa Y, Mitsuishi N, Ishizaka K, Shin S, Miyake T, Murakami S, Sasagawa T, Kondo T. Radial Spin Texture in Elemental Tellurium with Chiral Crystal Structure. Phys Rev Lett 2020; 124:136404. [PMID: 32302163 DOI: 10.1103/physrevlett.124.136404] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Accepted: 02/10/2020] [Indexed: 06/11/2023]
Abstract
The chiral crystal is characterized by a lack of mirror symmetry and inversion center, resulting in the inequivalent right- and left-handed structures. In the noncentrosymmetric crystal structure, the spin and momentum of electrons are expected to be locked in the reciprocal space with the help of the spin-orbit interaction. To reveal the spin textures of chiral crystals, we investigate the spin and electronic structure in a p-type semiconductor, elemental tellurium, with the simplest chiral structure by using spin- and angle-resolved photoemission spectroscopy. Our data demonstrate that the highest valence band crossing the Fermi level has a spin component parallel to the electron momentum around the Brillouin zone corners. Significantly, we have also confirmed that the spin polarization is reversed in the crystal with the opposite chirality. The results indicate that the spin textures of the right- and left-handed chiral crystals are hedgehoglike, leading to unconventional magnetoelectric effects and nonreciprocal phenomena.
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Affiliation(s)
- M Sakano
- Institute for Solid State Physics (ISSP), The University of Tokyo, Kashiwa 277-8581, Japan
- Quantum-Phase Electronics Center (QPEC) and Department of Applied Physics, The University of Tokyo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - M Hirayama
- Department of Physics, Tokyo Institute of Technology, Meguro-ku, Tokyo 152-8551, Japan
- Tokodai Institute for Element Strategy (TIES), Tokyo Institute of Technology, Meguro-ku, Tokyo 152-8551, Japan
- RIKEN Center for Emergent Matter Science (CEMS), Wako, Saitama 351-0198, Japan
| | - T Takahashi
- Materials and Structures Laboratory (MSL), Tokyo Institute of Technology, Yokohama, Kanagawa 226-8503, Japan
| | - S Akebi
- Institute for Solid State Physics (ISSP), The University of Tokyo, Kashiwa 277-8581, Japan
| | - M Nakayama
- Institute for Solid State Physics (ISSP), The University of Tokyo, Kashiwa 277-8581, Japan
| | - K Kuroda
- Institute for Solid State Physics (ISSP), The University of Tokyo, Kashiwa 277-8581, Japan
| | - K Taguchi
- Graduate School of Science, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8526, Japan
| | - T Yoshikawa
- Graduate School of Science, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8526, Japan
| | - K Miyamoto
- Hiroshima Synchrotron Radiation Center (HiSOR), Hiroshima University, Higashi-Hiroshima, Hiroshima 739-0046, Japan
| | - T Okuda
- Hiroshima Synchrotron Radiation Center (HiSOR), Hiroshima University, Higashi-Hiroshima, Hiroshima 739-0046, Japan
| | - K Ono
- Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan
| | - H Kumigashira
- Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan
- Institute of Multidisciplinary Research for Advanced Materials (IMRAM), Tohoku University, Sendai 980-8577, Japan
| | - T Ideue
- Quantum-Phase Electronics Center (QPEC) and Department of Applied Physics, The University of Tokyo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Y Iwasa
- Quantum-Phase Electronics Center (QPEC) and Department of Applied Physics, The University of Tokyo, Bunkyo-ku, Tokyo 113-8656, Japan
- RIKEN Center for Emergent Matter Science (CEMS), Wako, Saitama 351-0198, Japan
| | - N Mitsuishi
- Quantum-Phase Electronics Center (QPEC) and Department of Applied Physics, The University of Tokyo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - K Ishizaka
- Quantum-Phase Electronics Center (QPEC) and Department of Applied Physics, The University of Tokyo, Bunkyo-ku, Tokyo 113-8656, Japan
- RIKEN Center for Emergent Matter Science (CEMS), Wako, Saitama 351-0198, Japan
| | - S Shin
- Institute for Solid State Physics (ISSP), The University of Tokyo, Kashiwa 277-8581, Japan
| | - T Miyake
- Research Center for Computational Design of Advanced Functional Materials (CD-FMat), AIST, Tsukuba, Ibaraki 305-8568, Japan
| | - S Murakami
- Department of Physics, Tokyo Institute of Technology, Meguro-ku, Tokyo 152-8551, Japan
- Tokodai Institute for Element Strategy (TIES), Tokyo Institute of Technology, Meguro-ku, Tokyo 152-8551, Japan
| | - T Sasagawa
- Materials and Structures Laboratory (MSL), Tokyo Institute of Technology, Yokohama, Kanagawa 226-8503, Japan
| | - Takeshi Kondo
- Institute for Solid State Physics (ISSP), The University of Tokyo, Kashiwa 277-8581, Japan
- AIST-UTokyo Advanced Operando-Measurement Technology Open Innovation Laboratory (OPERANDO-OIL), Kashiwa, Chiba 277-8581, Japan
- Trans-scale Quantum Science Institute, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
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12
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Iwai N, Okuda T, Kagawa K. Gastrointestinal: Natural progression of early gastric cancer causing pyloric stenosis. J Gastroenterol Hepatol 2020; 35:9. [PMID: 31273829 DOI: 10.1111/jgh.14733] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Accepted: 05/17/2019] [Indexed: 12/09/2022]
Affiliation(s)
- N Iwai
- Department of Gastroenterology and Hepatology, Fukuchiyama City Hospital, Fukuchiyama, Japan
| | - T Okuda
- Department of Gastroenterology and Hepatology, Fukuchiyama City Hospital, Fukuchiyama, Japan
| | - K Kagawa
- Department of Gastroenterology and Hepatology, Fukuchiyama City Hospital, Fukuchiyama, Japan
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Marković I, Hooley CA, Clark OJ, Mazzola F, Watson MD, Riley JM, Volckaert K, Underwood K, Dyer MS, Murgatroyd PAE, Murphy KJ, Fèvre PL, Bertran F, Fujii J, Vobornik I, Wu S, Okuda T, Alaria J, King PDC. Weyl-like points from band inversions of spin-polarised surface states in NbGeSb. Nat Commun 2019; 10:5485. [PMID: 31792208 PMCID: PMC6888910 DOI: 10.1038/s41467-019-13464-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Accepted: 11/08/2019] [Indexed: 11/09/2022] Open
Abstract
Band inversions are key to stabilising a variety of novel electronic states in solids, from topological surface states to the formation of symmetry-protected three-dimensional Dirac and Weyl points and nodal-line semimetals. Here, we create a band inversion not of bulk states, but rather between manifolds of surface states. We realise this by aliovalent substitution of Nb for Zr and Sb for S in the ZrSiS family of nonsymmorphic semimetals. Using angle-resolved photoemission and density-functional theory, we show how two pairs of surface states, known from ZrSiS, are driven to intersect each other near the Fermi level in NbGeSb, and to develop pronounced spin splittings. We demonstrate how mirror symmetry leads to protected crossing points in the resulting spin-orbital entangled surface band structure, thereby stabilising surface state analogues of three-dimensional Weyl points. More generally, our observations suggest new opportunities for engineering topologically and symmetry-protected states via band inversions of surface states.
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Affiliation(s)
- I Marković
- SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews, KY16 9SS, United Kingdom.,Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Strasse 40, 01187, Dresden, Germany
| | - C A Hooley
- SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews, KY16 9SS, United Kingdom
| | - O J Clark
- SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews, KY16 9SS, United Kingdom
| | - F Mazzola
- SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews, KY16 9SS, United Kingdom
| | - M D Watson
- SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews, KY16 9SS, United Kingdom
| | - J M Riley
- SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews, KY16 9SS, United Kingdom
| | - K Volckaert
- SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews, KY16 9SS, United Kingdom
| | - K Underwood
- SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews, KY16 9SS, United Kingdom
| | - M S Dyer
- Department of Chemistry, University of Liverpool, Liverpool, L69 7ZD, United Kingdom
| | - P A E Murgatroyd
- Department of Physics, University of Liverpool, Liverpool, L69 7ZE, United Kingdom
| | - K J Murphy
- Department of Physics, University of Liverpool, Liverpool, L69 7ZE, United Kingdom
| | - P Le Fèvre
- Synchrotron SOLEIL, CNRS-CEA, L'Orme des Merisiers, Saint-Aubin-BP48, 91192, Gif-sur-Yvette, France
| | - F Bertran
- Synchrotron SOLEIL, CNRS-CEA, L'Orme des Merisiers, Saint-Aubin-BP48, 91192, Gif-sur-Yvette, France
| | - J Fujii
- Istituto Officina dei Materiali (IOM)-CNR, Laboratorio TASC, Area Science Park, S.S.14, Km 163.5, 34149, Trieste, Italy
| | - I Vobornik
- Istituto Officina dei Materiali (IOM)-CNR, Laboratorio TASC, Area Science Park, S.S.14, Km 163.5, 34149, Trieste, Italy
| | - S Wu
- Graduate School of Science, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, 739-8526, Japan
| | - T Okuda
- Hiroshima Synchrotron Radiation Center, Hiroshima University, 2-313 Kagamiyama, Higashi-Hiroshima, 739-0046, Japan
| | - J Alaria
- Department of Physics, University of Liverpool, Liverpool, L69 7ZE, United Kingdom
| | - P D C King
- SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews, KY16 9SS, United Kingdom.
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Harada T, Futamura S, Inoue Y, Sawada R, Okuda T, Kagawa K. P2.03-13 Acquired Resistance to Afatinib in Non-Small Cell Lung Cancer with EGFR G719X Mutation. J Thorac Oncol 2019. [DOI: 10.1016/j.jtho.2019.08.1460] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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15
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Daikoku T, Okuda T, Kawai M, Morita N, Tanaka T, Takemoto M, Fukuda Y, Takahashi K, Nomura N, Shiraki K. Growth activation of influenza virus by trypsin and effect of T-705 (favipiravir) on trypsin-optimized growth condition. Acta Virol 2019; 63:309-315. [PMID: 31507197 DOI: 10.4149/av_2019_311] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Influenza virus is activated by proteolytic cleavage of hemagglutinin by trypsin. After determining the optimal trypsin concentration, intracellular and extracellular influenza A/PR/8/34 (H1N1) and A/Victoria/361/2011 (H3N2) virus productions were compared in cultures treated with T-705 (favipiravir) and GS 4071 (an active form of oseltamivir). Although both drugs efficiently inhibited extracellular viral RNA release in a dose-dependent manner, T-705 inhibited it to the level of the inoculum without trypsin treatment, while GS 4071 inhibited it to a final level 10 times higher than that without trypsin. T-705 inhibited intracellular viral RNA production to the level of input virus in both trypsin-treated and untreated cells. In contrast, GS 4071 dose-dependently inhibited intracellular viral RNA production in cells treated with trypsin but allowed viral RNA synthesis. The level of maximum inhibition by GS 4071was 10 times higher than that of cells without trypsin and 1,000 times greater than the inoculum titer in cells without trypsin. T-705 inhibited both intracellular and extracellular virus production 1,000 and 10 times more strongly, respectively, than GS 4071. T-705 has powerful anti-influenza activity in the absence of trypsin and even in the trypsin-optimized growth condition, suggesting the therapeutic advantage in treatment of influenza complicated with bacterial pneumonia. Keywords: influenza; T-705; Tamiflu; trypsin; bacterial trypsin-like protease.
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16
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17
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Miyamoto K, Wortelen H, Okuda T, Henk J, Donath M. Circular-polarized-light-induced spin polarization characterized for the Dirac-cone surface state at W(110) with C 2v symmetry. Sci Rep 2018; 8:10440. [PMID: 29993001 PMCID: PMC6041308 DOI: 10.1038/s41598-018-28693-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Accepted: 06/26/2018] [Indexed: 11/15/2022] Open
Abstract
The C2v surface symmetry of W(110) strongly influences a spin-orbit-induced Dirac-cone-like surface state and its characterization by spin- and angle-resolved photoelectron spectroscopy. In particular, using circular polarized light, a distinctive k-dependent spin texture is observed along the \documentclass[12pt]{minimal}
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\begin{document}$$\overline{{\boldsymbol{\Gamma }}{\boldsymbol{H}}}$$\end{document}ΓH¯ direction of the surface Brillouin zone. For all spin components Px, Py, and Pz, non-zero values are detected, while the initial-state spin polarization has only a Py component due to mirror symmetry. The observed complex spin texture of the surface state is controlled by transition matrix element effects, which include orbital symmetries of the involved electron states as well as the geometry of the experimental set-up.
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Affiliation(s)
- K Miyamoto
- Hiroshima Synchrotron Radiation Center, Hiroshima University, 2-313 Kagamiyama, Higashi-Hiroshima, 739-0046, Japan. .,Westfälische Wilhelms-Universität Münster, Physikalisches Institut, Wilhelm-Klemm-Straße 10, 48149, Münster, Germany.
| | - H Wortelen
- Westfälische Wilhelms-Universität Münster, Physikalisches Institut, Wilhelm-Klemm-Straße 10, 48149, Münster, Germany
| | - T Okuda
- Hiroshima Synchrotron Radiation Center, Hiroshima University, 2-313 Kagamiyama, Higashi-Hiroshima, 739-0046, Japan
| | - J Henk
- Martin-Luther-Universität Halle-Wittenberg, Institut für Physik, Von-Seckendorff-Platz 1, 06120, Halle, Germany
| | - M Donath
- Westfälische Wilhelms-Universität Münster, Physikalisches Institut, Wilhelm-Klemm-Straße 10, 48149, Münster, Germany
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18
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Takada M, Takeuchi M, Suzuki E, Sato F, Matsumoto Y, Torii M, Sakita-Kawaguchi N, Nakayama Y, Okuda T, Nishino H, Seo S, Hatano E, Toi M. Abstract PD2-07: Real-time navigation for sentinel lymph node biopsy in breast cancer patients using projection mapping with indocyanine green fluorescence. Cancer Res 2018. [DOI: 10.1158/1538-7445.sabcs17-pd2-07] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Background)
Sentinel lymph node (SLN) biopsy using indocyanine green fluorescence (fICG) method showed equal or better identification rate compared with blue dye or radioisotope (RI) method. In the fICG method, lymphatic vessels which drain into the SLNs can be seen through skin or subcutaneous tissue using near infrared camera (Photodynamic Eye®: PDE), and we can easily find the SLNs. However, whenever we observe the fluorescence images, we have to hold the PDE, turn off the operating light, and look at a monitor because fluorescence images cannot be seen directly. Medical imaging projection system (MIPS) is a new device which detects fluorescent emission from the organ and projects their images on the location of the fluorescence emission (Panasonic Connected Solutions Company, Japan). Projected images can be adjusted following the body movement or deformation of the organ. Therefore, MIPS could provide an option for real-time navigation for the SLN biopsy. The aim of this study was to evaluate the clinical utility of the MIPS.
Patients and methods)
Patients with clinically node-negative primary breast cancer underwent the fICG SLN biopsy using MIPS. Primary endpoint was identification rate of the fICG method using MIPS. At first, the study was conducted as an interventional study because the MIPS was the unapproved medical device. After approval of the MIPS, this study was conducted as an observational study. The study protocol was approved by the institutional review board at Kyoto University Hospital. All patients provided informed consent to participate in this study.
Results)
Between March 2016 and May 2017, 39 patients (40 procedures) underwent the fICG method SLN biopsy using MIPS. The median age was 55 years (range 32–74 years), and the median body mass index was 20.4 kg/m2 (range 17.7–27.7 kg/m2). About half had tumor stage T1 (58%) and 8 (20.0%) had DCIS. 8 procedures (20%) were performed after preoperative systemic therapy (PST). As MIPS itself can illuminate the operating field, SLN biopsy using MIPS was successfully performed without operating light in all procedures. At least one SLN was detected using MIPS for all procedures and the identification rate was 100% (95% CI: 91–100%). Median number of SLNs detected by MIPS was 3 (range 1–9) for all procedures, and 3 (range 2–8) for procedures after PST. Two pathologically positive SLNs and one SLN which included isolated tumor cells were detected by MIPS. In 25 procedures, RI was also used. 62 of 97 SLNs detected by MIPS (64%) were also detected by RI. However, no SLNs were detected only by RI.
Conclusions)
Although we still may not be able to avoid RI method because 25/40 (62.5%) procedures required the combined use of RI method, the fICG methods SLN biopsy using MIPS, which showed comparable identification rate of SLN with the conventional methods, could be useful tool with a view of allowing us to perform a real-time navigation surgery.
Acknowledgements)
This study was supported by Acceleration Transformative research for Medical innovation, Japan Agency for Medical Research and Development (AMED).
Citation Format: Takada M, Takeuchi M, Suzuki E, Sato F, Matsumoto Y, Torii M, Sakita-Kawaguchi N, Nakayama Y, Okuda T, Nishino H, Seo S, Hatano E, Toi M. Real-time navigation for sentinel lymph node biopsy in breast cancer patients using projection mapping with indocyanine green fluorescence [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr PD2-07.
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Affiliation(s)
- M Takada
- Kyoto University Hospital, Kyoto, Japan; Hyogo College of Medicine, Hyogo, Japan
| | - M Takeuchi
- Kyoto University Hospital, Kyoto, Japan; Hyogo College of Medicine, Hyogo, Japan
| | - E Suzuki
- Kyoto University Hospital, Kyoto, Japan; Hyogo College of Medicine, Hyogo, Japan
| | - F Sato
- Kyoto University Hospital, Kyoto, Japan; Hyogo College of Medicine, Hyogo, Japan
| | - Y Matsumoto
- Kyoto University Hospital, Kyoto, Japan; Hyogo College of Medicine, Hyogo, Japan
| | - M Torii
- Kyoto University Hospital, Kyoto, Japan; Hyogo College of Medicine, Hyogo, Japan
| | - N Sakita-Kawaguchi
- Kyoto University Hospital, Kyoto, Japan; Hyogo College of Medicine, Hyogo, Japan
| | - Y Nakayama
- Kyoto University Hospital, Kyoto, Japan; Hyogo College of Medicine, Hyogo, Japan
| | - T Okuda
- Kyoto University Hospital, Kyoto, Japan; Hyogo College of Medicine, Hyogo, Japan
| | - H Nishino
- Kyoto University Hospital, Kyoto, Japan; Hyogo College of Medicine, Hyogo, Japan
| | - S Seo
- Kyoto University Hospital, Kyoto, Japan; Hyogo College of Medicine, Hyogo, Japan
| | - E Hatano
- Kyoto University Hospital, Kyoto, Japan; Hyogo College of Medicine, Hyogo, Japan
| | - M Toi
- Kyoto University Hospital, Kyoto, Japan; Hyogo College of Medicine, Hyogo, Japan
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Abe H, Jitsuki S, Nakajima W, Murata Y, Higo N, Masuyama H, Mochizuki N, Komori T, Okuda T, Takahashi T. CRMP2 binding compound, T-817-maleic-acid, accelerates motor function recovery from brain damage. J Neurol Sci 2017. [DOI: 10.1016/j.jns.2017.08.1678] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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20
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Sato Y, Ohnuma H, Okamoto K, Miyamoto H, Hirakawa M, Uemura N, Kikuchi S, Sagawa T, Fujikawa K, Takahashi Y, Minami S, Okuda T, Takahashi M, Kato J, Takayama T. Phase II study of modified docetaxel, cisplatin and S-1 (mDCS) combination chemotherapy in patients with unresectable metastatic gastric cancer. Ann Oncol 2017. [DOI: 10.1093/annonc/mdx369.064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Abstract
CT, MR and angiographic findings of 6 patients with 9 skull metastases from hepatocellular carcinoma (HCC) were reviewed. In 3 of 6 patients, local pain or neurologic deficit was the initial main manifestation of the disease, although all had been treated for chronic liver disease. In the remaining 3 patients, skull metastases were detected following treatment of HCC. The metastatic lesions appeared as expansile osteolytic masses on CT and as hypervascular masses on angiography. All lesions were demonstrated on MR imaging. Compared with the brain parenchyma, the lesions were iso- or hypointense on T1-weighted and T2-weighted MR images. The lesions were moderately to markedly enhanced by Gd-DTPA. Flow voids were shown in the tumors in 5 lesions. HCC should be included in the differential diagnosis of an osteolytic hypervascular lesion of the skull, especially in Oriental patients. The relatively hypointense tumor on T2-weighted MR images associated with flow void, different from primary skull tumors or directly invasive tumors, may support the diagnosis of HCC metastasis.
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Affiliation(s)
- R. Murakami
- Department of Radiology, Kumamoto University School of Medicine, Kumamoto, Japan
| | - Y. Korogi
- Department of Radiology, Kumamoto University School of Medicine, Kumamoto, Japan
| | - Y. Sakamoto
- Department of Radiology, Kumamoto University School of Medicine, Kumamoto, Japan
| | - M. Takahashi
- Department of Radiology, Kumamoto University School of Medicine, Kumamoto, Japan
| | - T. Okuda
- Department of Radiology, Kumamoto City Hospital, Kumamoto, Japan
| | - T. Yasunaga
- Department of Radiology, Kumamoto City Hospital, Kumamoto, Japan
| | - R. Nishimura
- Department of Radiology, National Saishunso Hospital, Kumamoto, Japan
| | - S. Yoshimatsu
- Department of Radiology, Kumamoto Regional Medical Center, Kumamoto, Japan
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Ikushima I, Korogi Y, Hirai T, Sugahara T, Shigematsu Y, Okuda T, Takahashi M, Ushio Y. Evaluation of dural sinus invasion and extension of extra-axial intracranial tumors: The advantages of a high-resolution postcontrast 3-D gradient-echo technique. Acta Radiol 2016. [DOI: 10.1258/rsmacta.41.1.8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Objective: To assess the usefulness of a postcontrast 3-D Fourier transform (3DFT) gradient-echo (GRE) technique in dural sinus invasion and extension of extraaxial intracranial tumors in comparison with a conventional spin-echo (SE) technique. Material and Methods: Fourteen consecutive patients with 15 extra-axial tumors in contiguity with the dural sinus, including 14 meningiomas and 1 adenoid cystic carcinoma, underwent postcontrast T1-weighted SE and GRE MR studies. Detectability of dural sinus invasion and extension was evaluated using two sequences by two neuroradiologists in a blinded manner and compared with surgical results. Quantitative analysis was also performed to calculate the contrast-to-noise ratio (CNR) between lesion and dural sinus on SE and GRE images. The data were analyzed statistically using a matched paired t-test. Results: In the qualitative evaluation, the detectability of dural sinus invasion in 3DFT-GRE images was superior to that using SE images. The mean CNR for all lesions was 3.86 on SE images and 5.63 on 3DFT-GRE images ( p = 0.03). Conclusion: For evaluation of dural sinus invasion and the extension of extra-axial tumors, postcontrast 3DFT-GRE MR images were superior to conventional SE images.
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Affiliation(s)
- I. Ikushima
- Department of Radiology, Kumamoto University School of Medicine, Kumamoto, Japan
| | - Y. Korogi
- Department of Radiology, Kumamoto University School of Medicine, Kumamoto, Japan
| | - T. Hirai
- Department of Radiology, Kumamoto University School of Medicine, Kumamoto, Japan
| | - T. Sugahara
- Department of Radiology, Kumamoto University School of Medicine, Kumamoto, Japan
| | - Y. Shigematsu
- Department of Radiology, Kumamoto University School of Medicine, Kumamoto, Japan
| | - T. Okuda
- Department of Radiology, Kumamoto University School of Medicine, Kumamoto, Japan
| | - M. Takahashi
- Department of Radiology, Kumamoto University School of Medicine, Kumamoto, Japan
| | - Y. Ushio
- Department of Neurosurgery, Kumamoto University School of Medicine, Kumamoto, Japan
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23
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Suzuki J, Takahashi H, Tomida M, Hamajima K, Ohhashi Y, Okuda T. EP-1541: Effects of leaf position accuracy of robotic radiotherapy system on dose distribution. Radiother Oncol 2016. [DOI: 10.1016/s0167-8140(16)32791-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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24
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Sakano M, Okawa K, Kanou M, Sanjo H, Okuda T, Sasagawa T, Ishizaka K. Topologically protected surface states in a centrosymmetric superconductor β-PdBi2. Nat Commun 2015; 6:8595. [PMID: 26460338 PMCID: PMC4633943 DOI: 10.1038/ncomms9595] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Accepted: 09/08/2015] [Indexed: 11/22/2022] Open
Abstract
The topological aspects of electrons in solids can emerge in real materials, as represented by topological insulators. In theory, they show a variety of new magneto-electric phenomena, and especially the ones hosting superconductivity are strongly desired as candidates for topological superconductors. While efforts have been made to develop possible topological superconductors by introducing carriers into topological insulators, those exhibiting indisputable superconductivity free from inhomogeneity are very few. Here we report on the observation of topologically protected surface states in a centrosymmetric layered superconductor, β-PdBi2, by utilizing spin- and angle-resolved photoemission spectroscopy. Besides the bulk bands, several surface bands are clearly observed with symmetrically allowed in-plane spin polarizations, some of which crossing the Fermi level. These surface states are precisely evaluated to be topological, based on the Z2 invariant analysis in analogy to three-dimensional strong topological insulators. β-PdBi2 may offer a solid stage to investigate the topological aspect in the superconducting condensate. Materials possessing topologically non-trivial electronic surface states are predicted to host exotic Majorana fermion excitations in the superconducting state. Here, the authors demonstrate the existence of topologically-protected surface states in the centrosymmetric layered superconductor β-PdBi2.
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Affiliation(s)
- M Sakano
- Department of Applied Physics and Quantum-Phase Electronics Center (QPEC), The University of Tokyo, Tokyo 113-8656, Japan
| | - K Okawa
- Materials and Structures Laboratory, Tokyo Institute of Technology, Kanagawa 226-8503, Japan
| | - M Kanou
- Materials and Structures Laboratory, Tokyo Institute of Technology, Kanagawa 226-8503, Japan
| | - H Sanjo
- Department of Applied Physics and Quantum-Phase Electronics Center (QPEC), The University of Tokyo, Tokyo 113-8656, Japan
| | - T Okuda
- Hiroshima Synchrotron Radiation Center, Hiroshima University, Higashi-Hiroshima 739-0046, Japan
| | - T Sasagawa
- Materials and Structures Laboratory, Tokyo Institute of Technology, Kanagawa 226-8503, Japan
| | - K Ishizaka
- Department of Applied Physics and Quantum-Phase Electronics Center (QPEC), The University of Tokyo, Tokyo 113-8656, Japan
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25
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Okuyama N, Takeuchi T, Aono N, Oka N, Obata R, Yanagihori S, Okuda T, Kyono K. Impact of assisted oocyte activation on morphokinetics of early human embryos. Fertil Steril 2015. [DOI: 10.1016/j.fertnstert.2015.07.949] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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26
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Abbasi R, Abe M, Abu-Zayyad T, Allen M, Azuma R, Barcikowski E, Belz J, Bergman D, Blake S, Cady R, Chae M, Cheon B, Chiba J, Chikawa M, Cho W, Fujii T, Fukushima M, Goto T, Hanlon W, Hayashi Y, Hayashida N, Hibino K, Honda K, Ikeda D, Inoue N, Ishii T, Ishimori R, Ito H, Ivanov D, Jui C, Kadota K, Kakimoto F, Kalashev O, Kasahara K, Kawai H, Kawakami S, Kawana S, Kawata K, Kido E, Kim H, Kim J, Kim J, Kitamura S, Kitamura Y, Kuzmin V, Kwon Y, Lan J, Lim S, Lundquist J, Machida K, Martens K, Matsuda T, Matsuyama T, Matthews J, Minamino M, Mukai Y, Myers I, Nagasawa K, Nagataki S, Nakamura T, Nonaka T, Nozato A, Ogio S, Ogura J, Ohnishi M, Ohoka H, Oki K, Okuda T, Ono M, Oshima A, Ozawa S, Park I, Pshirkov M, Rodriguez D, Rubtsov G, Ryu D, Sagawa H, Sakurai N, Scott L, Shah P, Shibata F, Shibata T, Shimodaira H, Shin B, Shin H, Smith J, Sokolsky P, Springer R, Stokes B, Stratton S, Stroman T, Suzawa T, Takamura M, Takeda M, Takeishi R, Taketa A, Takita M, Tameda Y, Tanaka H, Tanaka K, Tanaka M, Thomas S, Thomson G, Tinyakov P, Tkachev I, Tokuno H, Tomida T, Troitsky S, Tsunesada Y, Tsutsumi K, Uchihori Y, Udo S, Urban F, Vasiloff G, Wong T, Yamane R, Yamaoka H, Yamazaki K, Yang J, Yashiro K, Yoneda Y, Yoshida S, Yoshii H, Zollinger R, Zundel Z. Measurement of the proton-air cross section with Telescope Array’s Middle Drum detector and surface array in hybrid mode. Int J Clin Exp Med 2015. [DOI: 10.1103/physrevd.92.032007] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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27
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Suzuki J, Okuda T, Sakaino S, Yokota N. SU-E-J-159: Analysis of Total Imaging Uncertainty in Respiratory-Gated Radiotherapy. Med Phys 2015. [DOI: 10.1118/1.4924244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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28
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Takimoto K, Chikamori T, Takebayashi H, Okuda T, Miyamoto S, Takuma Y, Inoue Y, Okabe T, Miyamoto K. Usefulness of the Walking Stroop Carpet in evaluating fall risks among the community-dwelling elderly. Physiotherapy 2015. [DOI: 10.1016/j.physio.2015.03.1455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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29
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Kikukawa H, Sakuradani E, Nishibaba Y, Okuda T, Ando A, Shima J, Shimizu S, Ogawa J. Production of cis-11-eicosenoic acid by Mortierella fungi. J Appl Microbiol 2015; 118:641-7. [PMID: 25495454 DOI: 10.1111/jam.12725] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2014] [Revised: 12/06/2014] [Accepted: 12/10/2014] [Indexed: 11/29/2022]
Abstract
AIM To find cis-11-eicosenoic acid (20:1ω9, EA)-producing micro-organisms. METHODS AND RESULTS We found EA-producing fungi by screening about 300 fungal strains and identified a major fatty acid accumulated in the Mortierella fungi as EA by means of GC-MS analysis. In particular, Mortierella chlamydospora CBS 529.75 produced a high amount of EA (36.3 mg g(-1) of dried cells) on cultivation at 28°C for 4 days and then at 12°C for 3 days. In the result of lipid analysis, most of the EA was a component of triacylglycerols, not phospholipids. CONCLUSION We found that M. chlamydospora CBS 529.75 was the best producer for the microbial production of EA. SIGNIFICANCE AND IMPACT OF THE STUDY EA is beneficial as a raw material for medical supplies and a moisturizing component of cosmetic creams. This is the first report of microbial production of EA.
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Affiliation(s)
- H Kikukawa
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
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30
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Okuda T, Ijichil S, Yamashita S, Yoshioka T, Nishigaki H, Kitawaki J. Diagnostic usefulness of FDG-PET/CT in advanced malignant lymphoma of the uterus: report of two cases. EUR J GYNAECOL ONCOL 2015; 36:737-741. [PMID: 26775364] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Summary Malignant lymphoma of the uterus is difficult to diagnose because of its rarity and nonspecific symptoms. However, recently, 18F-fluoro-2-deoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) has become an important non-invasive diagnostic tool for the management of lymphoma patients. The authors report two cases of malignant lymphoma of the uterus, in which FDG-PET/CT was useful for diagnosis. Examination using ultrasonography or magnetic resonance imaging (MRI) demonstrated a normal-sized uterus and normal endometrium, but FDG-PET/CT showed FDG accumulation in the uterine body in both cases. Endometrial biopsy revealed diffuse large B-cell lymphoma, and chemotherapy with rituximab, cyclophosphamide, adriamycin, vincristine, and prednisone (R-CHOP) was initiated immediately. Primary malignant lymphoma of the female genitalia is reported to be rare. The present authors' experience with FDG-PET/CT suggests that malignant lymphoma of the female genitalia (including metastasis) may not be as rare as previously reported. Uterine malignant lymphoma may be overlooked by the examination of ultrasound, CT, or MRI.
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31
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Muroga T, Nagasaka T, Li Y, Abe H, Ukai S, Kimura A, Okuda T. Fabrication and characterization of reference 9Cr and 12Cr-ODS low activation ferritic/martensitic steels. Fusion Engineering and Design 2014. [DOI: 10.1016/j.fusengdes.2014.01.010] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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32
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Takeuchi T, Nagao K, Aono N, Mori Y, Nakajo Y, Okuda T, Kyono K. Beneficial effect of microsurgical varicocelectomy on semen parameters and clinical outcome in severe male factor infertility. Fertil Steril 2014. [DOI: 10.1016/j.fertnstert.2014.07.644] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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33
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Suzuki R, Sakano M, Zhang YJ, Akashi R, Morikawa D, Harasawa A, Yaji K, Kuroda K, Miyamoto K, Okuda T, Ishizaka K, Arita R, Iwasa Y. Valley-dependent spin polarization in bulk MoS2 with broken inversion symmetry. Nat Nanotechnol 2014; 9:611-7. [PMID: 25064393 DOI: 10.1038/nnano.2014.148] [Citation(s) in RCA: 165] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2013] [Accepted: 06/24/2014] [Indexed: 05/04/2023]
Abstract
The valley degree of freedom of electrons is attracting growing interest as a carrier of information in various materials, including graphene, diamond and monolayer transition-metal dichalcogenides. The monolayer transition-metal dichalcogenides are semiconducting and are unique due to the coupling between the spin and valley degrees of freedom originating from the relativistic spin-orbit interaction. Here, we report the direct observation of valley-dependent out-of-plane spin polarization in an archetypal transition-metal dichalcogenide--MoS2--using spin- and angle-resolved photoemission spectroscopy. The result is in fair agreement with a first-principles theoretical prediction. This was made possible by choosing a 3R polytype crystal, which has a non-centrosymmetric structure, rather than the conventional centrosymmetric 2H form. We also confirm robust valley polarization in the 3R form by means of circularly polarized photoluminescence spectroscopy. Non-centrosymmetric transition-metal dichalcogenide crystals may provide a firm basis for the development of magnetic and electric manipulation of spin/valley degrees of freedom.
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Affiliation(s)
- R Suzuki
- 1] Quantum-Phase Electronics Centre (QPEC) and Department of Applied Physics, University of Tokyo, Tokyo 113-8656, Japan [2]
| | - M Sakano
- 1] Quantum-Phase Electronics Centre (QPEC) and Department of Applied Physics, University of Tokyo, Tokyo 113-8656, Japan [2]
| | - Y J Zhang
- Quantum-Phase Electronics Centre (QPEC) and Department of Applied Physics, University of Tokyo, Tokyo 113-8656, Japan
| | - R Akashi
- Quantum-Phase Electronics Centre (QPEC) and Department of Applied Physics, University of Tokyo, Tokyo 113-8656, Japan
| | - D Morikawa
- RIKEN Centre for Emergent Matter Science, Wako 351-0198, Japan
| | - A Harasawa
- Institute for Solid State Physics, University of Tokyo, Kashiwa, 277-8581, Japan
| | - K Yaji
- Institute for Solid State Physics, University of Tokyo, Kashiwa, 277-8581, Japan
| | - K Kuroda
- Graduate School of Science, Hiroshima University, Higashi-Hiroshima 739-8526, Japan
| | - K Miyamoto
- Hiroshima Synchrotron Radiation Centre, Hiroshima University, Higashi-Hiroshima 739-0046, Japan
| | - T Okuda
- Hiroshima Synchrotron Radiation Centre, Hiroshima University, Higashi-Hiroshima 739-0046, Japan
| | - K Ishizaka
- Quantum-Phase Electronics Centre (QPEC) and Department of Applied Physics, University of Tokyo, Tokyo 113-8656, Japan
| | - R Arita
- 1] Quantum-Phase Electronics Centre (QPEC) and Department of Applied Physics, University of Tokyo, Tokyo 113-8656, Japan [2] RIKEN Centre for Emergent Matter Science, Wako 351-0198, Japan
| | - Y Iwasa
- 1] Quantum-Phase Electronics Centre (QPEC) and Department of Applied Physics, University of Tokyo, Tokyo 113-8656, Japan [2] RIKEN Centre for Emergent Matter Science, Wako 351-0198, Japan
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Yamada K, Isobe K, Okuda T, Furukawa Y. Successive Phase Transitions and High Ionic Conductivity of Trichlorogermanate (II) Salts as Studied by 35C1 NQR and Powder X-Ray Diffraction. ACTA ACUST UNITED AC 2014. [DOI: 10.1515/zna-1994-1-238] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
A series of trichlorogermanate(II) salts (AGeCl3, A = Rb, Cs, CH3N H3, and (CH3)4N) have been synthesized and characterized by 35Cl NQR , 35Cl NMR , AC conductivity, DTA, and X-ray diffraction techniques. In the temperature range studied two, two, five, and four phases were confirmed for the Rb, Cs, CH3NH3, and (CH3)4N salts, respectively. From the 35Cl NQR and structural data, isolated pyramidal GeCl3 anions were recognized in the low temperature phases. With increasing temperature the relaxation times of the 35Cl NQR decreased exponentially and the signals disappeared far below the melting point. This suggests that the reorientation of the anion about the pseudo three-fold axis is excited. With further increase in temperature, the ionic conductivity of CH3NH3GeCl3 and (CH3)4NGeCl3 increased drastically at the phase transitions to their cubic perovskite phases (CH3NH3GeCl3:σ= 10-1 Sm-1 at 400 K, (CH3)4NGeCl3: σ = 5 x 10-2 Sm-1 at 420 K). The mobile ion was confirmed to be the chloride ion by means of 35Cl NMR and X-ray diffraction.
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Affiliation(s)
- K. Yamada
- Department of Chemistry, Faculty of Science, Hiroshima University, Kagamiyama 1-3, Higashi-Hiroshima 724, Japan
| | - K. Isobe
- Department of Chemistry, Faculty of Science, Hiroshima University, Kagamiyama 1-3, Higashi-Hiroshima 724, Japan
| | - T. Okuda
- Department of Chemistry, Faculty of Science, Hiroshima University, Kagamiyama 1-3, Higashi-Hiroshima 724, Japan
| | - Y. Furukawa
- Faculty of School Education, Hiroshima University, Shinonome 3-1-33, Minami-ku, Hiroshima 734, Japan
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Zhu ZH, Veenstra CN, Zhdanovich S, Schneider MP, Okuda T, Miyamoto K, Zhu SY, Namatame H, Taniguchi M, Haverkort MW, Elfimov IS, Damascelli A. Photoelectron spin-polarization control in the topological insulator Bi2Se3. Phys Rev Lett 2014; 112:076802. [PMID: 24579623 DOI: 10.1103/physrevlett.112.076802] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2013] [Indexed: 06/03/2023]
Abstract
We study the manipulation of the spin polarization of photoemitted electrons in Bi2Se3 by spin- and angle-resolved photoemission spectroscopy. General rules are established that enable controlling the photoelectron spin-polarization. We demonstrate the ± 100% reversal of a single component of the measured spin-polarization vector upon the rotation of light polarization, as well as full three-dimensional manipulation by varying experimental configuration and photon energy. While a material-specific density-functional theory analysis is needed for the quantitative description, a minimal yet fully generalized two-atomic-layer model qualitatively accounts for the spin response based on the interplay of optical selection rules, photoelectron interference, and topological surface-state complex structure. It follows that photoelectron spin-polarization control is generically achievable in systems with a layer-dependent, entangled spin-orbital texture.
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Affiliation(s)
- Z-H Zhu
- Department of Physics & Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - C N Veenstra
- Department of Physics & Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - S Zhdanovich
- Department of Physics & Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - M P Schneider
- Department of Physics & Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - T Okuda
- Hiroshima Synchrotron Radiation Center, Hiroshima University, 2-313 Kagamiyama, Higashi-Hiroshima 739-0046, Japan
| | - K Miyamoto
- Hiroshima Synchrotron Radiation Center, Hiroshima University, 2-313 Kagamiyama, Higashi-Hiroshima 739-0046, Japan
| | - S-Y Zhu
- Graduate School of Science, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8526, Japan
| | - H Namatame
- Hiroshima Synchrotron Radiation Center, Hiroshima University, 2-313 Kagamiyama, Higashi-Hiroshima 739-0046, Japan
| | - M Taniguchi
- Hiroshima Synchrotron Radiation Center, Hiroshima University, 2-313 Kagamiyama, Higashi-Hiroshima 739-0046, Japan and Graduate School of Science, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8526, Japan
| | - M W Haverkort
- Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany and Quantum Matter Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - I S Elfimov
- Department of Physics & Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada and Quantum Matter Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - A Damascelli
- Department of Physics & Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada and Quantum Matter Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
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Okuda T, Ogino Y, Yamashita S, Ishii H, Kin S, Nagata A, Otsubo M, Kataoka H, Kitawaki J. Diagnostic laparoscopy identifies a peritoneal adenomatoid-like mesothelioma masquerading as ovarian cancer: a case report. EUR J GYNAECOL ONCOL 2014; 35:91-94. [PMID: 24654472] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The authors report a rare case of peritoneal adenomatoid mesothelioma in a woman with no history of asbestos exposure. A 61-year-old woman was originally suspected of having a bilateral ovarian tumor based on chest radiography and magnetic resonance imaging (MRI). Upon referral to our hospital, the presence of two solid masses was confirmed by enhanced MRI and 18F-fluorodeoxyglucose positron-emission tomography/computed tomography (18F-FDG-PET/CT). Physical examination was normal, as were serum concentrations of the tumor markers CA 19-9, CA 125, and CEA. Laparoscopic surgery showed a right ovarian tumor and laparoscopic right salpingo-oophorectomy and adhesiotomy were performed. Two months later, the patient underwent laparoscopic segmental resection of the sigmoid colon, with histological analysis identifying an adenomatoid-like tumor. The final diagnosis was peritoneal adenomatoid-like mesothelioma with invasion of the right ovary. This case report demonstrates that imaging techniques must be coupled with laparoscopic surgery for an accurate diagnosis of peritoneal mesothelioma.
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Abu-Zayyad T, Aida R, Allen M, Anderson R, Azuma R, Barcikowski E, Belz JW, Bergman DR, Blake SA, Cady R, Cheon BG, Chiba J, Chikawa M, Cho EJ, Cho WR, Fujii H, Fujii T, Fukuda T, Fukushima M, Gorbunov D, Hanlon W, Hayashi K, Hayashi Y, Hayashida N, Hibino K, Hiyama K, Honda K, Iguchi T, Ikeda D, Ikuta K, Inoue N, Ishii T, Ishimori R, Ivanov D, Iwamoto S, Jui CCH, Kadota K, Kakimoto F, Kalashev O, Kanbe T, Kasahara K, Kawai H, Kawakami S, Kawana S, Kido E, Kim HB, Kim HK, Kim JH, Kim JH, Kitamoto K, Kitamura S, Kitamura Y, Kobayashi K, Kobayashi Y, Kondo Y, Kuramoto K, Kuzmin V, Kwon YJ, Lan J, Lim SI, Machida S, Martens K, Matsuda T, Matsuura T, Matsuyama T, Matthews JN, Minamino M, Miyata K, Murano Y, Myers I, Nagasawa K, Nagataki S, Nakamura T, Nam SW, Nonaka T, Ogio S, Ohnishi M, Ohoka H, Oki K, Oku D, Okuda T, Oshima A, Ozawa S, Park IH, Pshirkov MS, Rodriguez DC, Roh SY, Rubtsov GI, Ryu D, Sagawa H, Sakurai N, Sampson AL, Scott LM, Shah PD, Shibata F, Shibata T, Shimodaira H, Shin BK, Shin JI, Shirahama T, Smith JD, Sokolsky P, Stokes BT, Stratton SR, Stroman T, Suzuki S, Takahashi Y, Takeda M, Taketa A, Takita M, Tameda Y, Tanaka H, Tanaka K, Tanaka M, Thomas SB, Thomson GB, Tinyakov P, Tkachev I, Tokuno H, Tomida T, Troitsky S, Tsunesada Y, Tsutsumi K, Tsuyuguchi Y, Uchihori Y, Udo S, Ukai H, Vasiloff G, Wada Y, Wong T, Wood M, Yamakawa Y, Yamane R, Yamaoka H, Yamazaki K, Yang J, Yoneda Y, Yoshida S, Yoshii H, Zhou X, Zollinger R, Zundel Z. Upper limit on the flux of photons with energies above1019 eVusing the Telescope Array surface detector. Int J Clin Exp Med 2013. [DOI: 10.1103/physrevd.88.112005] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Kamihara Y, Fujimi A, Kanisawa Y, Okuda T, Uemura N, Minami S, Doi T, Hashimoto A, Ishikawa K, Matsuno T. Diffuse Intrasinusoidal Liver Metastasis of Pancreatic Carcinoma Causing Fulminant Hepatic Failure. Ann Oncol 2013. [DOI: 10.1093/annonc/mdt460.161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Miyamoto K, Kimura A, Okuda T, Miyahara H, Kuroda K, Namatame H, Taniguchi M, Eremeev SV, Menshchikova TV, Chulkov EV, Kokh KA, Tereshchenko OE. Topological surface states with persistent high spin polarization across the Dirac point in Bi2Te2Se and Bi2Se2Te. Phys Rev Lett 2012; 109:166802. [PMID: 23215110 DOI: 10.1103/physrevlett.109.166802] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2012] [Indexed: 06/01/2023]
Abstract
Helical spin textures with marked spin polarizations of topological surface states have been unveiled for the first time by state-of-the-art spin- and angle-resolved photoemission spectroscopy for two promising topological insulators, Bi(2)Te(2)Se and Bi(2)Se(2)Te. Their highly spin-polarized natures are found to be persistent across the Dirac point in both compounds. This novel finding paves a pathway to extending the utilization of topological surface states of these compounds for future spintronic applications.
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Affiliation(s)
- K Miyamoto
- Hiroshima Synchrotron Radiation Center, Hiroshima University, 2-313 Kagamiyama, Higashi-Hiroshima 739-0046, Japan.
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Kuroda K, Miyahara H, Ye M, Eremeev SV, Koroteev YM, Krasovskii EE, Chulkov EV, Hiramoto S, Moriyoshi C, Kuroiwa Y, Miyamoto K, Okuda T, Arita M, Shimada K, Namatame H, Taniguchi M, Ueda Y, Kimura A. Experimental verification of PbBi2Te4 as a 3D topological insulator. Phys Rev Lett 2012; 108:206803. [PMID: 23003165 DOI: 10.1103/physrevlett.108.206803] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2011] [Indexed: 06/01/2023]
Abstract
The experimental evidence is presented of the topological insulator state in PbBi2Te4. A single surface Dirac cone is observed by angle-resolved photoemission spectroscopy with synchrotron radiation. Topological invariants Z2 are calculated from the ab initio band structure to be 1;(111). The observed two-dimensional isoenergy contours in the bulk energy gap are found to be the largest among the known three-dimensional topological insulators. This opens a pathway to achieving a sufficiently large spin current density in future spintronic devices.
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Affiliation(s)
- K Kuroda
- Graduate School of Science, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8526, Japan
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Miyamoto K, Kimura A, Kuroda K, Okuda T, Shimada K, Namatame H, Taniguchi M, Donath M. Spin-polarized Dirac-cone-like surface state with d character at W(110). Phys Rev Lett 2012; 108:066808. [PMID: 22401107 DOI: 10.1103/physrevlett.108.066808] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2011] [Indexed: 05/31/2023]
Abstract
The surface of W(110) exhibits a Dirac-cone-like state with d character within a spin-orbit-induced symmetry gap. As a function of the wave vector parallel to the surface, it shows a nearly massless energy dispersion and a pronounced spin polarization, which is antisymmetric with respect to the Brillouin zone center. In addition, the observed constant energy contours are strongly anisotropic for all energies. This discovery opens new pathways to the study of surface spin-density waves arising from a strong Fermi surface nesting as well as d-electron-based topological properties.
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Affiliation(s)
- K Miyamoto
- Hiroshima Synchrotron Radiation Center, Hiroshima University, Higashi-Hiroshima, Japan
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Nakai S, Zou G, Okuda T, Nishijima W, Hosomi M, Okada M. Polyphenols and fatty acids responsible for anti-cyanobacterial allelopathic effects of submerged macrophyte Myriophyllum spicatum. Water Sci Technol 2012; 66:993-999. [PMID: 22797226 DOI: 10.2166/wst.2012.272] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Myriophyllum spicatum is known to inhibit the growth of cyanobacteria such as Microcystis aeruginosa by releasing anti-cyanobacterial allelochemicals. The allelochemicals possibly responsible for the inhibition include five polyphenols and three fatty acids, but the extent to which these are indeed responsible for the anti-cyanobacterial effects is unclear. The goal of this research was to determine the contribution of these compounds to the allelopathic effect of M. spicatum on M. aeruginosa. We first collected information on the release rates of these compounds and then added the compounds to a cyanobacterial medium on the basis of their release rates so as to simulate their excretion by M. spicatum. Addition of the polyphenols and fatty acids inhibited the growth of M. aeruginosa, and the interaction of the polyphenols and fatty acids was additive. The EC50 of a polyphenol and fatty acid mixture was compared with that of M. spicatum itself as previously determined in a mixed culture system in which M. spicatum and M. aeruginosa were incubated. The former was about 1.9 times higher than that of the latter, the implication being that the inhibitory effect of the polyphenols and fatty acids contributed about 53% of the allelopathic effect of M. spicatum. This paper is the first to describe allelochemicals that account for a half of the anti-cyanobacterial allelopathic effect of a macrophyte.
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Affiliation(s)
- S Nakai
- Graduate School of Engineering, Hiroshima University, Higashi-hiroshima 739-8527, Japan.
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Hirai T, Kitajima M, Nakamura H, Okuda T, Sasao A, Shigematsu Y, Utsunomiya D, Oda S, Uetani H, Morioka M, Yamashita Y. Quantitative blood flow measurements in gliomas using arterial spin-labeling at 3T: intermodality agreement and inter- and intraobserver reproducibility study. AJNR Am J Neuroradiol 2011; 32:2073-9. [PMID: 21960503 DOI: 10.3174/ajnr.a2725] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE QUASAR is a particular application of the ASL method and facilitates the user-independent quantification of brain perfusion. The purpose of this study was to assess the intermodality agreement of TBF measurements obtained with ASL and DSC MR imaging and the inter- and intraobserver reproducibility of glioma TBF measurements acquired by ASL at 3T. MATERIALS AND METHODS Two observers independently measured TBF in 24 patients with histologically proved glioma. ASL MR imaging with QUASAR and DSC MR imaging were performed on 3T scanners. The observers placed 5 regions of interest in the solid tumor on rCBF maps derived from ASL and DSC MR images and 1 region of interest in the contralateral brain and recorded the measured values. Maximum and average sTBF values were calculated. Intermodality and intra- and interobsever agreement were determined by using 95% Bland-Altman limits of agreement and ICCs. RESULTS The intermodality agreement for maximum sTBF was good to excellent on DSC and ASL images; ICCs ranged from 0.718 to 0.884. The 95% limits of agreement ranged from 59.2% to 65.4% of the mean. ICCs for intra- and interobserver agreement for maximum sTBF ranged from 0.843 to 0.850 and from 0.626 to 0.665, respectively. The reproducibility of maximum sTBF measurements obtained by methods was similar. CONCLUSIONS In the evaluation of sTBF in gliomas, ASL with QUASAR at 3T yielded measurements and reproducibility similar to those of DSC perfusion MR imaging.
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Affiliation(s)
- T Hirai
- Department of Diagnostic Radiology, Kumamoto University, KumamotoJapan.
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Ohno S, Shudo K, Nakayama F, Yamazaki K, Ichikawa Y, Tanaka M, Okuda T, Harasawa A, Matsuda I, Kakizaki A. Enhanced silicon oxidation on titanium-covered Si(001). J Phys Condens Matter 2011; 23:305001. [PMID: 21709355 DOI: 10.1088/0953-8984/23/30/305001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We report on a core level photoemission study of the formation of an ultrathin SiO(x) layer grown at the interface of a titanium-covered Si(001) surface. Oxygen exposure at room temperature induces a large chemical shift of the Si 2p state, predominantly assigned to Si(4+). The results indicate that a SiO(2 - δ) layer, close to the stoichiometry of SiO(2), is formed below the TiO(x) film. The thickness of the SiO(2 - δ) layer is estimated to be ∼ 0.9 nm, corresponding to three to four oxide layers. Further chemical shift caused by annealing is attributed to the formation of titanium silicate (TiSi(x)O(y)).
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Affiliation(s)
- S Ohno
- Faculty of Engineering, Yokohama National University, 79-5 Tokiwadai, Hodogaya-ku, Yokohama 240-8501, Japan.
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Kim S, Ye M, Kuroda K, Yamada Y, Krasovskii EE, Chulkov EV, Miyamoto K, Nakatake M, Okuda T, Ueda Y, Shimada K, Namatame H, Taniguchi M, Kimura A. Surface scattering via bulk continuum states in the 3D topological insulator Bi2Se3. Phys Rev Lett 2011; 107:056803. [PMID: 21867088 DOI: 10.1103/physrevlett.107.056803] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2010] [Revised: 06/14/2011] [Indexed: 05/31/2023]
Abstract
We have performed scanning tunneling microscopy and differential tunneling conductance (dI/dV) mapping for the surface of the three-dimensional topological insulator Bi(2)Se(3). The fast Fourier transformation applied to the dI/dV image shows an electron interference pattern near Dirac node despite the general belief that the backscattering is well suppressed in the bulk energy gap region. The comparison of the present experimental result with theoretical surface and bulk band structures shows that the electron interference occurs through the scattering between the surface states near the Dirac node and the bulk continuum states.
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Affiliation(s)
- Sunghun Kim
- Graduate School of Science, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8526, Japan
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Ishizaka K, Bahramy MS, Murakawa H, Sakano M, Shimojima T, Sonobe T, Koizumi K, Shin S, Miyahara H, Kimura A, Miyamoto K, Okuda T, Namatame H, Taniguchi M, Arita R, Nagaosa N, Kobayashi K, Murakami Y, Kumai R, Kaneko Y, Onose Y, Tokura Y. Giant Rashba-type spin splitting in bulk BiTeI. Nat Mater 2011; 10:521-526. [PMID: 21685900 DOI: 10.1038/nmat3051] [Citation(s) in RCA: 225] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2011] [Accepted: 05/19/2011] [Indexed: 05/30/2023]
Abstract
There has been increasing interest in phenomena emerging from relativistic electrons in a solid, which have a potential impact on spintronics and magnetoelectrics. One example is the Rashba effect, which lifts the electron-spin degeneracy as a consequence of spin-orbit interaction under broken inversion symmetry. A high-energy-scale Rashba spin splitting is highly desirable for enhancing the coupling between electron spins and electricity relevant for spintronic functions. Here we describe the finding of a huge spin-orbit interaction effect in a polar semiconductor composed of heavy elements, BiTeI, where the bulk carriers are ruled by large Rashba-like spin splitting. The band splitting and its spin polarization obtained by spin- and angle-resolved photoemission spectroscopy are well in accord with relativistic first-principles calculations, confirming that the spin splitting is indeed derived from bulk atomic configurations. Together with the feasibility of carrier-doping control, the giant-Rashba semiconductor BiTeI possesses excellent potential for application to various spin-dependent electronic functions.
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Affiliation(s)
- K Ishizaka
- Department of Applied Physics, University of Tokyo, Tokyo 113-8656, Japan.
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Kuwahara H, Okuda T, Tomioka Y, Kimura T, Asamitsu A, Tokura Y. Phase Diagram and Anisotropic Transport Properties of Nd1-xSrxMnO3 Crystals. ACTA ACUST UNITED AC 2011. [DOI: 10.1557/proc-494-83] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
ABSTRACTWe have investigated electronic transport and magnetic properties of perovskite-type Nd1-xSrxMnO3 crystals with change of controlled hole-doping level (0.30≤x≤0.80). The electronic phase diagram of Nd1-xSrxMnO3 was obtained by systematic measurements of magnetization (magnetic structure), resistivity, and lattice parameter. We have also studied the anisotropie transport properties of x=0.50 and 0.55 crystals with different magnetic structures: CE-type antiferromagnetic (AF) structure for x=0.50 and A-type layered AF one for x=0.55. In the case of the x=0.55 crystal, the metallic behavior was observed within the ferromagnetic (F) layers, while along the AF-coupling direction the crystal remains insulating over the whole temperature region. The observed large anisotropy is due to the magnetic as well as orbital-ordering induced confinement of the spin-polarized carriers within the F sheets. The nearly isotropie transport behavior has been confirmed for the CE-type AF charge-ordered state in the x=0.50 crystal.
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Kuroda K, Ye M, Kimura A, Eremeev SV, Krasovskii EE, Chulkov EV, Ueda Y, Miyamoto K, Okuda T, Shimada K, Namatame H, Taniguchi M. Experimental realization of a three-dimensional topological insulator phase in ternary chalcogenide TlBiSe₂. Phys Rev Lett 2010; 105:146801. [PMID: 21230855 DOI: 10.1103/physrevlett.105.146801] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2010] [Indexed: 05/30/2023]
Abstract
We report the first observation of a topological surface state on the (111) surface of the ternary chalcogenide TlBiSe₂ by angle-resolved photoemission spectroscopy. By tuning the synchrotron radiation energy we reveal that it features an almost ideal Dirac cone with the Dirac point well isolated from bulk continuum states. This suggests that TlBiSe₂ is a promising material for realizing quantum topological transport.
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Affiliation(s)
- K Kuroda
- Graduate School of Science, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8526, Japan
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Kuroda K, Arita M, Miyamoto K, Ye M, Jiang J, Kimura A, Krasovskii EE, Chulkov EV, Iwasawa H, Okuda T, Shimada K, Ueda Y, Namatame H, Taniguchi M. Hexagonally deformed Fermi surface of the 3D topological insulator Bi2Se3. Phys Rev Lett 2010; 105:076802. [PMID: 20868066 DOI: 10.1103/physrevlett.105.076802] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2010] [Indexed: 05/29/2023]
Abstract
A hexagonal deformation of the Fermi surface of Bi2Se3 has been for the first time observed by angle-resolved photoemission spectroscopy. This is in contrast to the general belief that Bi2Se3 possesses an ideal Dirac cone. The hexagonal shape is found to disappear near the Dirac node, which would protect the surface state electrons from backscattering. It is also demonstrated that the Fermi energy of naturally electron-doped Bi2Se3 can be tuned by 1% Mg doping in order to realize the quantum topological transport.
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Affiliation(s)
- K Kuroda
- Graduate School of Science, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8526, Japan
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Fukuoka H, Hirai T, Okuda T, Shigematsu Y, Sasao A, Kimura E, Hirano T, Yano S, Murakami R, Yamashita Y. Comparison of the added value of contrast-enhanced 3D fluid-attenuated inversion recovery and magnetization-prepared rapid acquisition of gradient echo sequences in relation to conventional postcontrast T1-weighted images for the evaluation of leptomeningeal diseases at 3T. AJNR Am J Neuroradiol 2010; 31:868-73. [PMID: 20037130 DOI: 10.3174/ajnr.a1937] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE The usefulness of contrast-enhanced 3D T2-FLAIR MR imaging for the evaluation of leptomeningeal diseases has not been systematically investigated. The purpose of this study was to assess the value added by contrast-enhanced 3D T2-FLAIR and MPRAGE sequences to conventional postcontrast T1-weighted images in the evaluation of leptomeningeal diseases. We also undertook in vitro studies in attempts to understand the consequences of our patient study. MATERIALS AND METHODS Twelve patients with confirmed leptomeningeal diseases underwent postcontrast T1-weighted, MPRAGE, and 3D T2-FLAIR imaging at 3T. Two radiologists independently assessed the presence of additional information on postcontrast 3D MR images compared with postcontrast T1-weighted images. The effect of different Gd concentrations and flow velocities on the signal intensity on 3D T2-FLAIR images was investigated in vitro. RESULTS According to both reviewers, 3D T2-FLAIR images yielded significantly more information than did MPRAGE images (P < .05 and P < .01, respectively). In the in vitro study, 3D T2-FLAIR was more highly sensitive to low Gd concentrations and less sensitive to high Gd concentrations than were T1-weighted or MPRAGE sequences. On 3D T2-FLAIR sequences, at a flow velocity exceeding 1.0 cm/s, the signal intensity of blood-mimicking fluids at concentrations of 0 and 0.1 mmol/L was as low as at 1.3 mmol/L. CONCLUSIONS For the depiction of leptomeningeal diseases, postcontrast 3D T2-FLAIR provides more additional information than postcontrast MPRAGE imaging. The superiority of the 3D T2-FLAIR sequence is associated with its high sensitivity to flow.
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Affiliation(s)
- H Fukuoka
- Department of Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan
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