625 results on '"Mitsuru Itoh"'
Search Results
2. Bortezomib-cyclophosphamide-dexamethasone induction/consolidation and bortezomib maintenance for transplant-eligible newly diagnosed multiple myeloma: phase 2 multicenter trial
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Hiroyuki Muranushi, Junya Kanda, Masayuki Kobayashi, Takeshi Maeda, Toshiyuki Kitano, Masaaki Tsuji, Yasunori Ueda, Takayuki Ishikawa, Masaharu Nohgawa, Mitsumasa Watanabe, Kazunori Imada, Toshinori Moriguchi, Mitsuru Itoh, Hitoshi Ohno, Akihito Yonezawa, Hirokazu Hirata, Nobuyoshi Arima, Kohsuke Asagoe, Naoyuki Anzai, Kayoko Nagata, Shinji Yasuno, Yoshihiro Kuwabara, Hiromi Kitao, Ihhwa Kim, Kiyomi Kawagishi, Kenji Ueshima, Shinjiro Tominari, Takeo Nakayama, Kouhei Yamashita, and Akifumi Takaori-Kondo
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multiple myeloma ,bortezomib ,cyclophosphamide ,autologous stem cell transplantation ,induction therapy ,consolidation therapy ,maintenance therapy ,japan ,Diseases of the blood and blood-forming organs ,RC633-647.5 - Abstract
Objectives: We conducted a phase II trial to prospectively evaluate the efficacy and safety of bortezomib-cyclophosphamide-dexamethasone (VCD) induction, autologous stem cell transplantation (ASCT), VCD consolidation, and bortezomib maintenance in transplant-eligible newly diagnosed multiple myeloma (NDMM) patients in Japan (UMIN000010542). Methods: From 2013 to 2016, 42 patients with a median age of 58 (range 42–65) years with NDMM were enrolled in 15 centers. The primary endpoint was the complete response (CR) /stringent CR (sCR) rate after transplantation, and overall/progression-free survival rates were also evaluated. Results: Following induction therapy, the overall response rate was obtained in 71% of patients, including a CR/sCR of 10% and a very good partial response (VGPR) of 26%. Twenty-six of the 42 patients completed ASCT following the protocol and CR/sCR and VGPR rate 100 days after ASCT was 26% and 17%, respectively. During consolidation therapy, 3 of the 24 patients achieved deeper responses. Eight of the 18 patients completed 2-year bortezomib maintenance without disease progression and grade 3/4 toxicities. Five patients were VGPR or partial response after ASCT but maintained response with 2-year bortezomib maintenance. Two-year overall and progression-free survival rates were 92.5% (95% confidence interval [CI]: 78.5%−97.5%) and 62.6% (95% CI: 45.8%−75.5%), respectively. Grade 3/4 toxicities (≥ 10%) included neutropenia (19%) and anemia (17%) in induction, and thrombocytopenia (29%) in consolidation. Conclusion: VCD induction/consolidation and bortezomib maintenance with ASCT for NDMM resulted in a high CR/sCR rate and provided good overall/progression-free survival in Japan.
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- 2022
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3. Mild Acute Graft-Versus-Host Disease Improves Outcomes After HLA-Haploidentical-Related Donor Transplantation Using Posttransplant Cyclophosphamide and Cord Blood Transplantation
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Fumiya Wada, Junya Kanda, Kimimori Kamijo, Masashi Nishikubo, Satoshi Yoshioka, Takayuki Ishikawa, Yasunori Ueda, Takashi Akasaka, Yasuyuki Arai, Kiyotaka Izumi, Hirokazu Hirata, Takashi Ikeda, Akihito Yonezawa, Naoyuki Anzai, Mitsumasa Watanabe, Kazunori Imada, Kazuhiro Yago, Naoki Tamura, Mitsuru Itoh, Yuki Masuo, Akane Kunitomi, Tomoharu Takeoka, Toshiyuki Kitano, Nobuyoshi Arima, Masakatsu Hishizawa, Kohsuke Asagoe, Tadakazu Kondo, and Akifumi Takaori-Kondo
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Medicine - Abstract
Haploidentical-related donor transplantation using posttransplant cyclophosphamide (PTCy-haplo) and cord blood transplantation (CBT) are valid alternatives for patients with hematological malignancies when HLA-matched donor transplantation (MDT) is unavailable. However, the effects of graft-versus-host disease (GVHD) on outcomes after these transplants have not been fully elucidated. Therefore, we evaluated the effects of acute and chronic GVHD on transplant outcomes after PTCy-haplo transplants and compared them with CBT and MDT. We included a total of 914 adult patients with hematological malignancies in the Kyoto Stem Cell Transplantation Group registry who received PTCy-haplo (N = 120), CBT (N = 402), and MDT (N = 392), and achieved neutrophil engraftment. A multivariate analysis revealed that grade I–II acute GVHD improved of overall survival (OS) after PTCy-haplo [hazard ratio (HR) = 0.39, P = 0.018] and CBT (HR = 0.48, P < 0.001), but not after MDT (HR = 0.80, P = 0.267) compared with patients without acute GVHD. Grade I–II acute GVHD had a trend toward reducing the risk of nonrelapse mortality (NRM) after PTCy-haplo (HR = 0.13, P = 0.060) and this positive effect was significant after CBT (HR = 0.39, P = 0.003). A negative impact of grade III–IV acute GVHD on NRM was observed after CBT and MDT, but not after PTCy-haplo. Limited chronic GVHD had a positive impact on OS after CBT and MDT, but not after PTCy-haplo. In conclusion, mild acute GVHD improved outcomes after PTCy-haplo and CBT, and limited chronic GVHD improved outcomes after CBT and MDT. These data indicated that the effects of GVHD on transplant outcomes depended on transplant platforms.
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- 2023
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4. A computational search for wurtzite-structured ferroelectrics with low coercive voltages
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Hiroki Moriwake, Rie Yokoi, Ayako Taguchi, Takafumi Ogawa, Craig A. J. Fisher, Akihide Kuwabara, Yukio Sato, Takao Shimizu, Yosuke Hamasaki, Hiroshi Takashima, and Mitsuru Itoh
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Biotechnology ,TP248.13-248.65 ,Physics ,QC1-999 - Abstract
Ferroelectricity has recently been observed in wurtzite-structured Sc-doped AlN thin films, five years after our initial prediction of ferroelectricity in wurtzite compounds based on first-principles calculations. The thin films exhibited a much higher coercive voltage (3 MV/cm) than that of conventional perovskite-structured ferroelectric material PbTiO3, however, making it difficult to switch the films’ polarity and limiting their practical application. To identify tetrahedral ferroelectric materials with low coercive voltages, we have carried out a wider exploration of candidate binary compounds, from halides to chalcogenides to pnictogenides, using first-principles methods. The overall trend is for polarization switching barriers to decrease with decreasing anion-to-cation radius ratio, with the lowest barriers found in monovalent compounds such as the copper and silver halides; e.g., CuCl is calculated to have a switching barrier of 0.17 eV/f.u. and that of AgI is 0.22 eV/f.u., values similar in magnitude to that of PbTiO3 (0.20 eV/f.u.). Applying an epitaxial tensile strain to the basal plane is also effective for lowering the potential barrier further, with barriers in both AgI and CuCl decreasing to 0.04 eV/f.u. when a 5% in-plane expansion is applied. The results suggest that tetrahedral ferroelectrics with moderate coercive voltages (below 100 kV/cm) should be achievable.
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- 2020
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5. The effects of BaTiO3 nanodots density support on epitaxial LiCoO2 thin-film for high-speed rechargeability
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Sou Yasuhara, Shintaro Yasui, Takashi Teranishi, Yumi Yoshikawa, Tomoyasu Taniyama, and Mitsuru Itoh
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Industrial electrochemistry ,TP250-261 ,Chemistry ,QD1-999 - Abstract
LiCoO2 (LCO) is one of the most promising cathode materials for Li ion batteries (LIBs). However, LCO shows a rate-limiting step of Li+ migration between electrode and electrolyte interfaces, requiring LIBs to be charged under low-current conditions. For next generation batteries, it will be necessary to meet the demand for a shorter charging-time. We investigated a support method for the LCO surface to improve high C-rate performance, and revealed that the Li+ intercalation/de-intercalation reaction into/from LCO was accelerated by the introduction of a BaTiO3-LCO-electrolyte interface (triple-phase interface; TPI), due to the electric field concentration near the TPI. In this report, we investigate the dependence of high C-rate performance on the density of surface BaTiO3 nanodots using epitaxial LiCoO2 thin films created via pulsed laser deposition (PLD). As the number of nanodots increased, so did discharge capacity at 50C, becoming saturated at surface coverage over 22%. However, at 100C, the discharge capacity decreased at surface coverage over 40%. These results indicate that coalescence of nanodots reduces not only the TPI length but also the electrochemically active range at quite high C-rate. Therefore, we infer that optimal surface coverage should be varied depending on the C-rate. Keywords: High speed chargeability, Nanodots, Density, Dielectrics, LiCoO2
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- 2019
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6. Strain-mediated magnetic response in La0.67Sr0.33MnO3/SrTiO3/La0.67Sr0.33MnO3/BaTiO3 structure
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Anupama Swain, Katsuyoshi Komatsu, Mitsuru Itoh, Tomoyasu Taniyama, and Venkataiah Gorige
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Physics ,QC1-999 - Abstract
Electric field controlled magnetism is an exciting area of condensed matter physics to explore the device applications at ultra-low power consumption compared to the conventional current controlled or magnetic field controlled devices. In this study, an attempt was made to demonstrate electric field controlled magnetoresistance (MR) in a tri-layer structure consisting of La0.67Sr0.33MnO3 (LSMO) (40 nm)/SrTiO3 (10 nm)/LSMO (10 nm) grown on a 500-μm-thick BaTiO3 (001) (BTO) single crystal substrate by pulsed laser deposition technique. Epitaxial growth of the trilayer structure was confirmed by x-ray diffraction measurements. Jumps observed in the temperature-dependent magnetization curve at around the structural phase transitions of BTO ensure the strain-mediated magnetoelectric coupling between LSMO and BTO layers. A significant change in MR of this structure in applied electric fields does not show any polarity dependence. The findings are related to the lattice strain-mediated magnetoelectric coupling in ferromagnetic LSMO/ferroelectric BTO heterostructures.
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- 2018
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7. Hierarchical dielectric orders in layered ferroelectrics Bi2SiO5
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Younghun Kim, Jungeun Kim, Akihiko Fujiwara, Hiroki Taniguchi, Sungwng Kim, Hiroshi Tanaka, Kunihisa Sugimoto, Kenichi Kato, Mitsuru Itoh, Hideo Hosono, and Masaki Takata
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electron charge density ,electrostatic potential ,visualization of local polarization ,hierarchical dielectric ordering ,Crystallography ,QD901-999 - Abstract
Electric dipole engineering is now an emerging technology for high electron-mobility transistors, ferroelectric random access memory and multiferroic devices etc. Although various studies to provide insight into dipole moment behaviour, such as phase transition, order and disorder states, have been reported, macroscopic spontaneous polarization has been mainly discussed so far. Here, visualization of the electric dipole arrangement in layered ferroelectrics Bi2SiO5 by means of combined analysis of maximum entropy charge density and electrostatic potential distribution analysis based on synchrotron radiation X-ray powder diffraction data is reported. It was found that the hierarchical dipole orders, the weak-ferroelectric and ferroelectric configurations, were observed in the Bi2O2 and the SiO3 layers, respectively, and the ferrielectric configuration was realised by the interlayer interaction. This discovery provides a new method to visualize the local polarization in ferroelectric materials.
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- 2014
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8. Phase diagram of (Na0.5K0.5)NbO3-(Bi0.5Na0.5)ZrO3 solid solution
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Ruiping Wang and Mitsuru Itoh
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Lead-free ,piezoelectric ,niobate ,phase transition ,Electricity ,QC501-721 - Abstract
Phase diagram of (1−x)Na0.5K0.5NbO3–x(Bi0.5Na0.5)ZrO3 solid solution has been established from dielectric constant measurements and structure analyses. It is found that with increasing x, the C–T phase transition temperature TC−T and the T–O phase transition temperature TT−O decrease, while the O−R phase transition temperature TO−R increases. TT−O of NKN–xBNZ is much different from that of NKN–xBZ solid solution. The result could be mainly elucidated by the hybridization between the A-site ion and oxygen.
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- 2016
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9. Focus on advanced inorganic materials science: non-traditional concepts and approaches
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Mitsuru Itoh, Takashi Akatsu, Masaki Azuma, Keigo Kamata, and Toshio Kamiya
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Materials of engineering and construction. Mechanics of materials ,TA401-492 ,Biotechnology ,TP248.13-248.65 - Published
- 2015
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10. Phase transition and random-field induced domain wall response in quantum ferroelectrics SrTi18O3: review and perspective
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Mitsuru Itoh, Toshirou Yagi, Yoshiaki Uesu, Wolfgang Kleemann and Robert Blinc
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Materials of engineering and construction. Mechanics of materials ,TA401-492 ,Biotechnology ,TP248.13-248.65 - Abstract
The oxygen isotope exchange of 16O by 18O in SrTiO3 causes a drastic change from paraelectric to ferroelectric, due to the suppression of quantum fluctuation. The phase transition and origin of the huge domain wall response were evaluated by dielectric, magnetic (NMR), and optical measurements (SHG, light scattering). The results obtained corroborate (1) smeared ferroelectric transition at Tc due to quenched random field, (2) a quite large dielectric contribution from domain walls, (3) incomplete softening of the transverse optic mode, and (4) a large contribution from the relaxational mode to the phase transition. Quantitative explanations, given to individual results, may give hints to grasp the mechanism for the evolution of ferroelectricity, in which quantum fluctuation and random fields are dominant perturbations. Finally, some of the news studies on the SrTiO3 were also introduced.
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- 2004
11. NMR Study of Magnetic Structure and Spin Dynamics in α-CoV2O6
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Yu Kawasaki, Hiro Mori, Yutaka Kishimoto, Koichi Magishi, Koichi Nakamura, Zhangzhen He, and Mitsuru Itoh
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- 2023
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12. Effects of combined test dose and therapeutic drug monitoring strategy in exposure-directed busulfan
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Tomoki Iemura, Tadakazu Kondo, Atsushi Ueda, Takeshi Maeda, Toshio Kitawaki, Yasuyuki Arai, Junya Kanda, Takashi Ikeda, Kazunori Imada, Takayuki Ishikawa, Naoyuki Anzai, Mitsuru Itoh, Tomoharu Takeoka, Takashi Akasaka, Kazuhiro Yago, Akihito Yonezawa, Nobuyoshi Arima, Toshiyuki Kitano, Masaharu Nohgawa, Mitsumasa Watanabe, Toshinori Moriguchi, Kouhei Yamashita, Yasunori Ueda, Kana Matsumoto, and Akifumi Takaori-Kondo
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Hematology ,General Medicine - Published
- 2023
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13. Short-range magnetic correlation, metamagnetism, and coincident dielectric anomaly in Na5Co15.5Te6O36
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Rafikul Ali Saha, Jhuma Sannigrahi, Ilaria Carlomagno, S. D. Kaushik, Carlo Meneghini, Mitsuru Itoh, Vasudeva Siruguri, and Sugata Ray
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- 2023
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14. Establishment of a Predictive Model for GvHD-free, Relapse-free Survival after Allogeneic HSCT using Ensemble Learning
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Makoto Iwasaki, Junya Kanda, Yasuyuki Arai, Tadakazu Kondo, Takayuki Ishikawa, Yasunori Ueda, Kazunori Imada, Takashi Akasaka, Akihito Yonezawa, Kazuhiro Yago, Masaharu Nohgawa, Naoyuki Anzai, Toshinori Moriguchi, Toshiyuki Kitano, Mitsuru Itoh, Nobuyoshi Arima, Tomoharu Takeoka, Mitsumasa Watanabe, Hirokazu Hirata, Kosuke Asagoe, Isao Miyatsuka, Le My An, Masanori Miyanishi, and Akifumi Takaori-Kondo
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Adult ,Machine Learning ,Transplantation ,Recurrence ,Risk Factors ,Chronic Disease ,Hematopoietic Stem Cell Transplantation ,Humans ,Hematology ,Middle Aged ,Disease-Free Survival ,Retrospective Studies - Abstract
Graft-versus-host-disease-free, relapse-free survival (GRFS) is a useful composite endpoint that measures survival without relapse or significant morbidity after allogeneic hematopoietic stem cell transplantation (allo-HSCT). We aimed to develop a novel analytical method that appropriately handles right-censored data and competing risks to understand the risk for GRFS and each component of GRFS. This study was a retrospective data-mining study on a cohort of 2207 adult patients who underwent their first allo-HSCT at the Kyoto Stem Cell Transplantation Group (KSCTG), a multi-institutional joint research group of 17 transplantation centers in Japan. The primary endpoint was GRFS. A stacked ensemble of Cox proportional hazard regression and seven machine learning algorithms was applied to develop a prediction model. The median age of patients was 48 years. For GRFS, the stacked ensemble model achieved better predictive accuracy evaluated by C-index than other top-of-the-art competing risk models (ensemble model: 0.670, Cox-PH: 0.668, Random Survival Forest: 0.660, Dynamic DeepHit: 0.646). The probability of GRFS after 2 years was 30.54% for the high-risk and 40.69% for the low-risk group, respectively (hazard ratio [HR] compared to the low-risk group: 2.127; 95% CI: 1.19-3.80). We developed a novel predictive model for survival analysis that showed superior risk stratification to existing methods using a stacked ensemble of multiple machine learning algorithms., アンサンブル学習を用いた造血幹細胞移植予後予測モデルの開発 --機械学習を用いた新規生存時間解析手法の実装--. 京都大学プレスリリース. 2021-12-28.
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- 2022
15. Impact of a WEB notifying system on the coordination process length in the Japan Marrow Donor Program
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Masayuki Hino, Yukari Umemoto, Yosuke Makuuchi, Hiroshi Okamura, Hideo Koh, Keiko Hagiyama, Katsumi Orihara, Takafumi Nakao, Masaya Okada, Nobuhiko Uoshima, Mitsuru Itoh, Kimikazu Yakushijin, Akinori Nishikawa, Jun Ishikawa, Ishikazu Mizuno, Takayuki Ishikawa, and Takahiro Fukuda
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- 2022
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16. Chemical design of a new displacive-type ferroelectric
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Mitsuru Itoh, Yosuke Hamasaki, Hiroshi Takashima, Rie Yokoi, Ayako Taguchi, and Hiroki Moriwake
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Inorganic Chemistry - Abstract
Since the discovery of the ferroelectric perovskite-type oxide BaTiO3 in 1943, numerous materials have been surveyed as candidates for new ferroelectrics. Perovskite-type materials have played a leading role in basic research and applications of ferroelectric materials since the last century. Experimentalists and theoreticians have developed a new materials design stream for post-perovskite materials. In this stream, we have mainly focused on the role of covalency in the evolution of ferroelectricity for displacive-type ferroelectrics in oxides. This perspective surveys the following topics: (1) crossover from quantum paraelectric to ferroelectric through a ferroelectric quantum critical point, (2) the role of cation–oxygen covalency in ferroelectricity and the crossover to quantum paraelectric in perovskite-type compounds, (3) off-centerinduced ferroelectricity in perovskites, (4) second-order Jahn–Teller effect enhancement of ferroelectricity in lithium-niobate-type oxides, (5) the presence of four ferroelectric phases and structural transitions of phases of AFeO3 with decreasing radius of A (A = La–Al), (6) tetrahedral ferroelectrics of perovskiterelated Bi2SiO5 and wurtzites, (7) a rare type of polarization switching system in which the coordination number of ions in κ-Al2O3 systems changes between 4 and 6, and (8) lone-pair-electron-induced ferroelectrics in langasite-type compounds.
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- 2022
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17. Fluorination-Induced Asymmetry in Vacancy-Ordered Brownmillerite: Route to Multiferroic Behavior
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Payel Aich, Shreya Das, Shuvajit Halder, Carlo Meneghini, Desheng Fu, Vasudeva Siruguri, Som Datta Kaushik, Mitsuru Itoh, Tanusri Saha-Dasgupta, Sugata Ray, Aich, P., Das, S., Halder, S., Meneghini, C., Fu, D., Siruguri, V., Kaushik, S. D., Itoh, M., Saha-Dasgupta, T., and Ray, S.
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General Chemical Engineering ,Materials Chemistry ,General Chemistry - Abstract
Four distinct classes of multiferroics are usually being discussed in the literature, in which ferroelectricity is respectively driven by electronic lone pairs, geometry, charge ordering, and magnetism. Each class has its own shortcomings for technological applications. Here, through a combined experimental and theoretical investigation, we propose a mechanism to achieve multiferroicity in a single phase by engineering the anionic network and creating local geometric distortions in fluorinated, vacancy-ordered brownmillerite Ca2Mn2O5−xFy. The system exhibits both ferroelectricity and an antiferromagnetic order above room temperature, pointing toward a novel route to multiferroicity by anion mixing.
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- 2023
18. Comprehensive Structural Descriptor for Electrocatalytic Oxygen Evolution Activities of Iron Oxides
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Yuuki Sugawara, Yosuke Hamasaki, Takeo Yamaguchi, Eri Hayashi, Mitsuru Itoh, and Keigo Kamata
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Materials science ,Chemical engineering ,Electrochemistry ,Oxygen evolution ,Energy transformation ,Water splitting ,Heterogeneous catalysis ,Catalysis - Published
- 2021
19. Single-Crystal Synthesis of ε-Fe2O3-Type Oxides Exhibiting Room-Temperature Ferrimagnetism and Ferroelectric Polarization
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Haifeng Li, Ling Wang, Jinghong Fang, Jianding Yu, Hui Wang, Qin Li, Yinghao Zhu, Shintaro Yasui, Tsukasa Katayama, Yang Zhang, Koki Tachiyama, Zhengqian Fu, Yun Shi, Mitsuru Itoh, Si Wu, and Fangfang Xu
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Materials science ,Condensed matter physics ,Ferrimagnetism ,General Materials Science ,General Chemistry ,Condensed Matter Physics ,Polarization (electrochemistry) ,Single crystal ,Ferroelectricity - Published
- 2021
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20. Surface-supporting method of micropad deposition onto LiCoO2 epitaxial thin films to improve high C-rate performance
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Shintaro Yasui, Mitsuru Itoh, Takuya Hoshina, Takashi Teranishi, Takaaki Tsurumi, and Sou Yasuhara
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Materials science ,business.industry ,Epitaxial thin film ,Materials Chemistry ,Ceramics and Composites ,Optoelectronics ,General Chemistry ,Condensed Matter Physics ,business ,Deposition (chemistry) - Published
- 2021
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21. Suppression Mechanisms of the Solid-Electrolyte Interface Formation at the Triple-Phase Interfaces in Thin-Film Li-Ion Batteries
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Takuya Hoshina, Takaaki Tsurumi, Mitsuru Itoh, Sou Yasuhara, Shintaro Yasui, Osami Sakata, Takashi Teranishi, and Yutaka Majima
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Materials science ,X-ray photoelectron spectroscopy ,Chemical engineering ,Scanning electron microscope ,Phase (matter) ,Electrode ,General Materials Science ,Electrolyte ,Thin film ,Electrochemistry ,Ion - Abstract
Side reactions of the charge/discharge in Li-ion batteries (LIBs) generate a solid-electrolyte interface (SEI) onto an electrode surface, resulting in the degradation of the lifetime of a cell. The suppression of SEI formations has attracted much attention for achieving longer cyclable LIBs. Our research group has previously reported that few SEI were observed at triple-phase interfaces (TPIs) consisting of BaTiO3, LiCoO2, and electrolyte interfaces in LIBs with excellent cyclability and ultrahigh-speed chargeability. An investigation on the suppression mechanisms of SEI formations at TPIs should yield important information on understanding the undesirable side reactions. Therefore, we have explored the suppression mechanisms of SEI formations by preparing epitaxial thin films and evaluating the surface of the samples after the electrochemical treatment. The results of X-ray photoelectron spectroscopy and scanning electron microscopy with energy-dispersive X-ray analysis measurements suggested that the decomposition of LiPF6 was suppressed at TPIs, implying that the generation of PF5 via the decomposition of LiPF6 contributed to SEI formation.
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- 2021
22. Epitope Mismatch at HLA-DRB1 Associates with Reduced Relapse Risk in Cord Blood Transplantation for Standard-Risk Hematologic Malignancy
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Mari Morita-Fujita, Takero Shindo, Tomoki Iemura, Yasuyuki Arai, Junya Kanda, Kazuya Okada, Yasunori Ueda, Onda Yoshiyuki, Naoyuki Anzai, Takuto Mori, Takayuki Ishikawa, Yasuyuki Otsuka, Akihito Yonezawa, Naoki Yuhi, Kazunori Imada, Akifumi Oba, Mitsuru Itoh, Yoshio Okamoto, Toshiyuki Kitano, Takashi Ikeda, Shinichi Kotani, Takashi Akasaka, Kazuhiro Yago, Mitsumasa Watanabe, Masaharu Nohgawa, Masaaki Tsuji, Tomoharu Takeoka, Ryusuke Yamamoto, Nobuyoshi Arima, Noriyoshi Yoshinaga, Masakatsu Hishizawa, Kouhei Yamashita, Tadakazu Kondo, and Akifumi Takaori-Kondo
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Transplantation ,Molecular Medicine ,Immunology and Allergy ,Cell Biology ,Hematology - Published
- 2023
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23. Advantages of Higher Busulfan Dose Intensity in Fludarabine-Combined Conditioning for Patients with Acute Myeloid Leukemia Undergoing Cord Blood Transplantation
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Sho Shibata, Yasuyuki Arai, Tadakazu Kondo, Shohei Mizuno, Kaito Harada, Shigesaburo Miyakoshi, Naoyuki Uchida, Yumiko Maruyama, Tetsuya Eto, Yuna Katsuoka, Kosei Matsue, Kaichi Nishiwaki, Satoru Takada, Noriko Doki, Mitsuru Itoh, Koji Nagafuji, Toshiro Kawakita, Junji Tanaka, Takahiro Fukuda, Yoshiko Atsuta, and Masamitsu Yanada
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Fludarabine ,Transplantation ,Acute myeloid leukemia ,Cord blood transplantation ,Conditioning regimen ,Molecular Medicine ,Immunology and Allergy ,Cell Biology ,Hematology ,Busulfan - Abstract
The alkylating agent busulfan is commonly used as conditioning in allogeneic hematopoietic stem cell transplantation for acute myeloid leukemia (AML). However, a consensus has not yet been reached regarding the optimal busulfan dose in cord blood transplantation (CBT). Therefore, we conducted this large nationwide cohort study to retrospectively analyze the outcomes of CBT in patients with AML receiving busulfan at intermediate (6.4 mg/kg i.v.; BU2) or higher (12.8 mg/kg i.v.; BU4) doses within a fludarabine/i.v. busulfan (FLU/BU) regimen. Among 475 patients who underwent their first CBT following FLU/BU conditioning between 2007 and 2018, 162 received BU2 and 313 received BU4. Multivariate analysis identified BU4 as a significant factor for longer disease-free survival (hazard ratio [HR], .85; 95% confidence interval [CI], .75 to .97; P = .014) and a lower relapse rate (HR, .84; 95% CI, .72 to .98; P = .030). No significant differences were observed in non-relapse mortality between BU4 and BU2 (HR, 1.05; 95% CI, .88-1.26; P = .57). Subgroup analyses showed that BU4 provided significant benefits for patients who underwent transplantation while not in complete remission (CR) and those age
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- 2023
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24. Room-Temperature Antiferroelectricity in Multiferroic Hexagonal Rare-Earth Ferrites
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Tetsuya Hasegawa, Shishin Mo, Tsukasa Katayama, Yosuke Hamasaki, Jun Younes Louhi Kasahara, Shintaro Yasui, Mitsuru Itoh, and Akira Chikamatsu
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010302 applied physics ,Materials science ,Condensed matter physics ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,Ferroelectricity ,Pulsed laser deposition ,Phase (matter) ,Electric field ,0103 physical sciences ,Antiferroelectricity ,Polar ,General Materials Science ,Multiferroics ,Thin film ,0210 nano-technology - Abstract
The antiferroelectric (AFE) phase, in which nonpolar and polar states are switchable by an electric field, is a recent discovery in promising multiferroics of hexagonal rareearth manganites (ferrites), h-RMn(Fe)O3. However, this phase has so far only been observed at 60−160 K, which restricts key investigations into the microstructures and magnetoelectric behaviors. Herein, we report the successful expansion of the AFE temperature range (10−300 K) by preparing h-DyFeO3 films through epitaxial stabilization. Room-temperature scanning transmission electron microscopy reveals that the AFE phase originates from a nanomosaic structure comprising AFE P3̅c1 and ferroelectric P63cm domains with small domain sizes of 1− 10 nm. The nanomosaic structure is stabilized by a low c/a ratio derived from the large ionic radius of Dy3+. Furthermore, weak ferromagnetism and magnetocapacitance behaviors are observed. Below 10 K, the film exhibits an M-shaped magnetocapacitance versus magnetic field curve, indicating unusual magnetoelectric coupling in the AFE phase.
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- 2021
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25. Impact of Donor Source on Allogeneic Hematopoietic Stem Cell Transplantation for Mature T Cell and Natural Killer Cell Neoplasms in the Kyoto Stem Cell Transplantation Group
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Masakatsu Hishizawa, Yasunori Ueda, Toshiyuki Kitano, Nobuyoshi Arima, Naoyuki Anzai, Mitsuru Itoh, Junya Kanda, Mizuki Watanabe, Akihito Yonezawa, Kazunori Imada, Mitsumasa Watanabe, Kazuhiro Yago, Momoko Nishikori, Masaharu Nohgawa, Toshinori Moriguchi, Tomoharu Takeoka, Takashi Akasaka, Tadakazu Kondo, Akifumi Takaori-Kondo, Takayuki Ishikawa, and Yasuyuki Arai
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Oncology ,medicine.medical_specialty ,T-Lymphocytes ,medicine.medical_treatment ,Graft vs Host Disease ,Hematopoietic stem cell transplantation ,Natural killer cell ,Neoplasms ,Internal medicine ,medicine ,Humans ,Bone Marrow Transplantation ,Retrospective Studies ,Transplantation ,business.industry ,Donor selection ,Hazard ratio ,Hematopoietic Stem Cell Transplantation ,Hematology ,medicine.disease ,Killer Cells, Natural ,Leukemia ,medicine.anatomical_structure ,Cord Blood Stem Cell Transplantation ,Bone marrow ,Stem cell ,business - Abstract
Although allogeneic hematopoietic stem cell transplantation (allo-HSCT) is the key strategy to cure patients with mature T and natural killer (NK) cell lymphomas/leukemia, especially those with relapsed/refractory diseases, there is no consensus strategy for donor selection. We retrospectively analyzed the outcomes of allo-HSCT in 111 patients in 15 Japanese institutions as a multi-institutional joint research project. Thirty-nine patients received bone marrow or peripheral blood stem cell transplantation from related donors (rBMT/rPBSCT), 37 received BMT/PBSCT from unrelated donors (uBMT/uPBSCT), and 35 received cord blood transplantation (CBT). Overall survival (OS) and progression-free survival (PFS) at 4 years were 42% and 34%, respectively. The cumulative incidences of relapse and nonrelapse mortality were 43% and 25%. In multivariate analysis, CBT showed comparable OS with rBMT/rPBSCT (rBMT/rPBSCT versus CBT: hazard ratio [HR], 1.63; P = .264) and better OS compared with uBMT/uPBSCT (HR, 2.99; P = .010), with a trend toward a lower relapse rate (rBMT/rPBSCT versus CBT: HR, 2.60; P = .010; uBMT/uPBSCT versus CBT: HR, 2.05; P = .082). This superiority of CBT was more definite in on-disease patients (OS: rBMT/rPBSCT versus CBT: HR, 5.52; P = .021; uBMT/uPBSCT versus CBT: HR, 6.80; P = .007). Better disease control was also strongly associated with better OS and PFS with lower relapse rate. In conclusion, allo-HSCT is beneficial for the survival of patients with mature T and NK cell lymphomas/leukemia if performed in a timely fashion. Since CBT showed favorable survival with a lower relapse risk, it could be a preferred alternative, especially in on-disease patients.
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- 2020
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26. Influence of Comorbid Psychiatric Disorders on the Risk of Development of Alcohol Dependence by Genetic Variations ofALDH2andADH1B
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Hitoshi Maesato, Mitsuru Kimura, Tomoko Yonemoto, Mitsuru Itoh, Sachio Matsushita, Hideki Nakayama, Yosuke Yumoto, Fumihiko Ueno, and Chie Iwahara
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Male ,medicine.medical_specialty ,030508 substance abuse ,Medicine (miscellaneous) ,Alcohol use disorder ,Toxicology ,03 medical and health sciences ,0302 clinical medicine ,Risk Factors ,mental disorders ,medicine ,Humans ,Genetic Predisposition to Disease ,Risk factor ,Psychiatry ,ALDH2 ,business.industry ,Aldehyde Dehydrogenase, Mitochondrial ,Mental Disorders ,Panic disorder ,Alcohol dependence ,Alcohol Dehydrogenase ,Genetic Variation ,ADH1B ,Middle Aged ,medicine.disease ,Personality disorders ,Alcoholism ,Psychiatry and Mental health ,Attention Deficit Disorder with Hyperactivity ,Case-Control Studies ,0305 other medical science ,business ,030217 neurology & neurosurgery ,Agoraphobia - Abstract
Background Inactive aldehyde dehydrogenase-2 (ALDH2) is a well-known deterrent to the development of alcohol use disorder (AUD), and however, some individuals with inactive ALDH2 do go on to develop AUD. These alcoholics are likely to have strong risk factors for the development of this disorder. Using a model of alcoholics with inactive ALDH2 (the AIA model), we investigated the unique characteristics of alcoholics with inactive ALDH2 in an attempt to identify the risk factors for AUD. In this study, we focused on comorbid psychiatric and personality disorders as potential risk factors for AUD. Methods The subjects were 103 male alcoholics with inactive ALDH2 (AIAs), 87 age- and ADH1B genotype-matched alcoholics with active ALDH2 (AAAs) and 200 age-matched healthy men. The alcoholics were divided into 4 subgroups according to their ALDH2 and ADH1B genotypes (inactive ALDH2 vs. active ALDH2, usual ADH1B vs. superactive ADH1B). To assess the participants' comorbid psychiatric disorders, we conducted semi-structured interviews using the Japanese translation of SSAGA version 2. We compared the prevalence of comorbid psychiatric and personality disorders among groups with different combinations of the ALDH2 and ADH1B genotypes. Results The prevalence of attention-deficit/hyperactivity disorder (ADHD) was significantly higher in the AIAs with usual ADH1B than in the other 3 subgroups of alcoholics. In contrast, the prevalence rates of agoraphobia and panic disorder were significantly lower in the AIAs with superactive ADH1B than in the other 3 subgroups of alcoholics. Conclusions This study suggested that (i) ADHD is a risk factor for AUD, consistent with previous reports; (ii) agoraphobia and panic disorder may have deterrent effects against the development of AUD in individuals with inactive ALDH2, probably attributable to the similarity between the symptoms of agoraphobia and panic disorder and the adverse reactions to consumption of alcohol in subjects with inactive ALDH2.
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- 2020
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27. Cation-Deficiency-Induced Crystal-Site Engineering for ZnGa2O4:Mn2+ Thin Film
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Tomoyasu Taniyama, Mitsuru Itoh, Shintaro Yasui, and Takuro Dazai
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Photoluminescence ,010405 organic chemistry ,Band gap ,Chemistry ,Analytical chemistry ,Phosphor ,010402 general chemistry ,01 natural sciences ,0104 chemical sciences ,Pulsed laser deposition ,Inorganic Chemistry ,Crystal ,Lattice constant ,Physical and Theoretical Chemistry ,Thin film ,Luminescence - Abstract
Zn-deficient spinel-type ZnGa2O4:Mn2+ phosphor thin films were prepared using pulsed laser deposition. With an increase (decrease) in the Zn deficiency (concentration) of the films, changes in lattice constant, optical band gap, and photoluminescence spectra were observed. All films without γ-Ga2O3:Mn showed green luminescence attributable to the transition from the 4T1 state to the 6A1 state. In addition, the spectral shape changed depending on the temperature. The luminescence spectra have two peaks resulting from the Mn2+ ions located in the tetrahedral and octahedral sites. These peaks had different thermal quenching temperatures, which were around 320 and 260 K, respectively. Therefore, the spectral shape changed with increasing temperature. The spectral shape also depended on the Zn concentration. With an increase (decrease) in the Zn concentration (deficiency) of the films, the intensity of emission from Td increased in comparison with that from Oh. Therefore, the position of Mn2+ was controlled by Zn deficiency similarly to the effect of crystal-site engineering.
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- 2020
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28. Redox-Based Multilevel Resistive Switching in AlFeO3 Thin-Film Heterostructures
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Badari Narayana Rao, Tsukasa Katayama, Takanori Kiguchi, Mitsuru Itoh, Shintaro Yasui, Takahisa Shiraishi, Yefei Han, and Yosuke Hamasaki
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Hardware_MEMORYSTRUCTURES ,Materials science ,business.industry ,Schottky barrier ,Iron oxide ,Heterojunction ,Redox ,Electronic, Optical and Magnetic Materials ,Non-volatile memory ,chemistry.chemical_compound ,chemistry ,Simple (abstract algebra) ,Resistive switching ,Materials Chemistry ,Electrochemistry ,Optoelectronics ,Thin film ,business - Abstract
Next-generation nonvolatile memory devices require many functionalities such as high-speed processing, low power consumption, lightweight, and a simple structure. The use of heterostructures with r...
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- 2020
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29. Switchable third ScFeO3 polar ferromagnet with YMnO3-type structure
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Akihiro Akama, Shintaro Yasui, Tsukasa Katayama, Takanori Kiguchi, Tomoyasu Taniyama, Mitsuru Itoh, Yosuke Hamasaki, and Takahisa Shiraishi
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Materials science ,Condensed matter physics ,Magnetism ,02 engineering and technology ,General Chemistry ,021001 nanoscience & nanotechnology ,Polarization (waves) ,01 natural sciences ,Ferroelectricity ,Condensed Matter::Materials Science ,Ferromagnetism ,Electric field ,Magnet ,0103 physical sciences ,Materials Chemistry ,Polar ,010306 general physics ,0210 nano-technology ,Perovskite (structure) - Abstract
Polar magnets are important materials in fundamental science and technology. However, the requirements for a polar nature are generally incompatible with those for magnetism, and thus there are few polar magnets. At the order and disorder boundaries of cations in ABO3 compounds, two polar ferromagnets of ScFeO3 with polar-corundum-type and LiNbO3-type structures were previously prepared by high-pressure synthesis. Here, we prepared a third ScFeO3 polar ferromagnet with an YMnO3-type structure using a heteroepitaxial film technique and characterized its physical properties. The YMnO3-type ScFeO3 film on a perovskite electrode showed a ferroelectric P–E hysteresis loop with Pr ∼ 4.9 μC cm−2. Only YMO-type ScFeO3 has switchable polarization by the external electric field among the three ScFeO3 polar magnets. Magnetic measurements confirmed weak ferromagnetism (TN = 195 K), which is the highest observed in the hexagonal family.
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- 2020
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30. Investigation of ferrimagnetism and ferroelectricity in AlxFe2−xO3 thin films
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Shintaro Yasui, Mitsuru Itoh, Badari Narayana Rao, Ayako Taguchi, Hiroki Moriwake, Yosuke Hamasaki, and Tsukasa Katayama
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Materials science ,Condensed matter physics ,02 engineering and technology ,General Chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Ferroelectricity ,Magnetization ,Ferrimagnetism ,Electrical resistivity and conductivity ,0103 physical sciences ,Materials Chemistry ,Curie temperature ,Magnetocapacitance ,Thin film ,010306 general physics ,0210 nano-technology ,Polarization (electrochemistry) - Abstract
AlxFe2−xO3 (x-AFO) thin films, belonging to the κ-Al2O3 family, are interesting because they show room temperature ferrimagnetism and have a polar crystal structure. These types of materials are being studied to observe simultaneous ferrimagnetism and ferroelectricity, and the possibility of coupling between the two. However, it is difficult to realise ferroelectric properties at room temperature, due to the low resistivity of the films. In this work, we have optimized the synthesis conditions to obtain x-AFO (0.5 ≤ x ≤ 1) thin films with high resistance. While magnetic measurements confirmed room temperature ferrimagnetism of the films, the maximum magnetization was observed for the composition x = 0.8. In addition, the Curie temperature was found to be influenced by oxygen pressure during deposition. Ferroelectric measurements on the films showed small remnant polarization (∼0.5–2 μC cm−2). In contrast, the predicted polarization from first principles calculations was calculated to be between 21 and 26 μC cm−2. The analysis also suggested that ferroelectric domain-switching occurs through shearing of in-plane oxygen layers. The presence of multiple in-plane domains, which oppose polarization switching of adjacent domains, is suggested to be the cause of the small observed polarization. The magnetocapacitance measurements showed weak magnetic coupling with the capacitance.
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- 2020
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31. Optical selection rules of the magnetic excitation in the S=12 one-dimensional Ising-like antiferromagnet BaCo2V2O8
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Shojiro Kimura, Hiroaki Onishi, Akira Okutani, Mitsuru Akaki, Yasuo Narumi, Masayuki Hagiwara, Kouichi Okunishi, Koichi Kindo, Zhangzhen He, Tomoyasu Taniyama, and Mitsuru Itoh
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- 2022
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32. Coexistence of HLA and KIR ligand mismatches as a risk factor for viral infection early after cord blood transplantation
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Tomoki, Iemura, Yasuyuki, Arai, Toshio, Kitawaki, Junya, Kanda, Tadakazu, Kondo, Yasunori, Ueda, Takuto, Mori, Kazunori, Imada, Akihito, Yonezawa, Kazuhiro, Yago, Naoyuki, Anzai, Shinichi, Kotani, Masaharu, Nohgawa, Toshiyuki, Kitano, Mitsuru, Itoh, Nobuyoshi, Arima, Toshinori, Moriguchi, Mitsumasa, Watanabe, Masaaki, Tsuji, Kouhei, Yamashita, and Akifumi, Takaori-Kondo
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Receptors, KIR ,HLA Antigens ,Risk Factors ,Virus Diseases ,Histocompatibility Antigens Class I ,Hematopoietic Stem Cell Transplantation ,Humans ,Cord Blood Stem Cell Transplantation ,Ligands - Abstract
Viral infection is one of the lethal adverse events after cord blood transplantation (CBT). Human leukocyte antigen (HLA) and killer immunoglobulin-like receptor (KIR) ligand divergences can increase the risk of viral infection due to conflicting interactions between virus-infected cells and immune cells. However, the relationship between these disparities and the frequency of viral infection after CBT remains to be evaluated. Herein, we have conducted a retrospective multicenter study to assess the effect of HLA and KIR ligand mismatches on viral infections after CBT. The study included 429 patients, among which 126 viral infections occurred before day 100. Viral infection was significantly associated with poorer overall survival (OS; hazard ratio [HR] 1.74, p 0.01). Patients harboring ≥3 mismatches in the HLA allele and inhibitory KIR ligand mismatches (HLAKIR mismatches) had a significantly greater prevalence of viral infection (HR 1.66, p = 0.04). Thus, patients with HLAKIR mismatches had poorer outcomes in terms of non-relapse mortality (HR 1.61, p = 0.05). Our study demonstrates the unfavorable impacts of HLAKIR mismatches on viral infections and non-relapse mortality after CBT. Evaluating the viral infection risk and performance of an appropriate and early intervention in high-risk patients and optimizing the graft selection algorithm could improve the outcome of CBTs.
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- 2021
33. Ferroelectric and magnetic properties in ε-Fe2O3 epitaxial film
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Shintaro Yasui, Shinya Sawai, Takanori Kiguchi, Yosuke Hamasaki, Mitsuru Itoh, and Tsukasa Katayama
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Condensed Matter::Materials Science ,Phase transition ,Materials science ,Physics and Astronomy (miscellaneous) ,Condensed matter physics ,Field (physics) ,Magnetism ,Electric field ,Coercivity ,Epitaxy ,Polarization (waves) ,Ferroelectricity - Abstract
The phase stability, ferroelectricity, and magnetism of highly crystalline epitaxial e-Fe2O3 films deposited on SrTiO3(111) substrates are reported. Temperature-dependent x-ray diffraction measurements revealed that α-Fe2O3 appeared as a secondary phase after samples were annealed up to 1000 °C. A clear saturated and opened polarization–electric field hysteresis loop with the remnant polarization ∼2.6 μC cm−2 and coercive electric field ∼100 kV cm−1 was obtained at room temperature using a conventional ferroelectric measurement technique. The magnetic phase transition was observed at 155 K. Magnetization–magnetic field measurements revealed that magnetic softening via the phase transition accompanied a reduction in the coercive field from 10 to 6.8 kOe, which is smaller than the coercive field reduction previously observed for e-Fe2O3 nanoparticles.
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- 2021
34. Crystal Structure-Controlled Electrocatalysis on Iron-Based Oxides Toward Oxygen Evolution in Alkaline Media: Trend and Mechanism
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Yuuki Sugawara, Keigo Kamata, Satomi Ueno, Atsushi Ishikawa, Eri Hayashi, Mitsuru Itoh, Yosuke Hamasaki, Yoshitaka Tateyama, and Takeo Yamaguchi
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Present energy issues have increasingly stimulated the demand for the development of clean and sustainable energy platforms which can achieve net zero carbon emissions. Renewable energy resources are quite promising candidates for the construction of sustainable decarbonized society. One of examples of harnessing renewable energy-derived electricity is the electrolysis of earth-abundant water into hydrogen, which is a prominent carbon-free chemical fuel with a high weight energy density. Compared with polymer electrolyte water electrolysis in acidic environment, electrochemical alkaline water splitting can employ inexpensive nonprecious metals as electrocatalysts, which can make this technology a large-scale and cost-effective process. However, the anodic oxygen evolution reaction (OER) in the water splitting has a large overpotential, and it is a great bottleneck for widespread use. Thus, highly active and inexpensive electrocatalysts for OER are desired to overcome this concern. Iron (Fe) is a very earth-abundant element that is a quite cheap and non-toxic metal, and thus it is a potential candidate as electrocatalyst for OER. Previous studies have reported several multimetal oxides with Fe and other metallic elements, such as perovskite and brownmillerite types, which have attracted great attentions due to their facile synthesis and easily tunable OER activities by element substitution and doping. However, most of these studies focused on the choice of elements. Contrarily, the effects of crystal structures on OER activity have not yet been sufficiently interpreted, and it can be a crucial aspect to understand the OER electrocatalysis on Fe-based oxides and for the rational design of outstanding OER catalysts. In this study, we aim to comprehensively understand the effects of crystal structures on electrocatalytic OER activities on Fe-based oxides. To obtain versatile insights into OER electrocatalysis, we collected OER performances of Fe-based simple and bimetal oxides from our experiments and literature, and their structural characteristics were obtained from databases for inorganic compounds. Thus, we found that OER efficiencies on the Fe-based oxides were correlated with Fe–O bond lengths in their crystals; i.e., a shorter Fe–O bond length led to a higher OER activity.[1] We then exploited databases to mine potential candidates based on the structure–activity relationship and selected unreported Fe-based bimetal and trimetal oxides with various structures, which can dramatically accelerate our catalyst research. We synthesized these Fe-based multimetal oxides and evaluated their OER activity in alkaline media; remarkably, the OER efficiency on the unreported Fe-based multimetal oxides also exhibited excellent correlation with Fe–O bond lengths, as plotted in Figure 1. It is notable that the trend in the Fe–O bond length and OER activity is applicable to a wide variety of Fe-based simple, bimetal, and trimetal oxides regardless of chemical compositions, crystal categories, and Fe valence states. Furthermore, machine learning analysis proved that Fe–O bond length is the most dominant structural descriptor for OER efficiency compared with other structural parameters.[2] However, it is required to overcome the abovementioned catalytic trend because theoretical Fe–O bond length in Fe-based oxides is limited, and superior OER catalysts cannot be achieved according to this design guideline. Hence, we attempted to switch the OER electrocatalytic mechanism on a Fe-based oxide by the arrangement of crystal structure because different mechanisms should be involved in different descriptors; i.e., the mechanism switch could surpass the abovementioned catalytic trend. Thus, we found post-spinel CaFe2O4 that comprises a large amount of edge-shared FeO6 connectivity in its crystal. DFT calculations unveiled that the structural characteristics induced an unprecedented OER mechanism, multi-iron-site mechanism, where OER process goes through a reaction intermediate with an O–O bridge on multiple Fe sites as depicted in upper side in Figure 1. Consequently, CaFe2O4 exhibited prominent OER activity despite long Fe–O bond length in its crystal.[3] These findings provide a novel insight into the OER electrocatalysis on Fe-based oxides and contribute to the innovation of electrochemical hydrogen production. The part of this paper is based on results obtained from a project, JPNP14021, commissioned by the New Energy and Industrial Technology Development Organization (NEDO). Authors acknowledge the PRESTO program (No. JPMJPR15S3) of the JST. The part of DFT calculations was carried out on the supercomputers at NIMS, Hokkaido Univ., Kyushu Univ., and the HPCI systems (project codes: hp180115, hp200131). The part of this work was supported by JSPS KAKENHI Grant Number 20H00314 and 20K15087. References [1] Y. Sugawara, K. Kamata, E. Hayashi, M. Itoh, Y. Hamasaki, T. Yamaguchi ChemElectroChem, 2021, 8, 4466. [2] Y. Sugawara. S. Ueno, K. Kamata, T. Yamaguchi, ChemElectroChem, 2022, 9, in press. [3] Y. Sugawara, K. Kamata, A. Ishikawa, Y. Tateyama, T Yamaguchi, ACS Appl. Energy Mater., 2021, 4, 3057. Figure 1
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- 2022
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35. A surface-supporting method for an anode material of Li4Ti5O12 via an epitaxial thin film approach
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Mitsuru Itoh, Takaaki Tsurumi, Shintaro Yasui, Sou Yasuhara, Takuya Hoshina, and Takashi Teranishi
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Materials science ,Physics and Astronomy (miscellaneous) ,Diffusion ,Epitaxial thin film ,General Engineering ,General Physics and Astronomy ,Relative permittivity ,Cathode ,Anode ,law.invention ,law ,Cathode material ,Electric field ,Composite material ,Deposition (law) - Abstract
High-speed rechargeability is essential for next-generation secondary batteries. We previously reported that a surface-supporting material deposited on a cathode material accelerates Li-ion motions between an electrode−electrolyte interface by an electric field concentration at a supporting material–cathode–electrolyte (triple-phase) interface (TPI). In addition, a high relative permittivity material was found to be a promising supporting material with which to reinforce the electric field concentration at TPIs. However, the TPI's effects on anode materials remains to be revealed. To demonstrate those effects, we prepared CeO2 or BaTiO3 micropads deposited on Li4Ti5O12 epitaxial thin films. Compared with the cathodes, CeO2 micropads deposited on Li4Ti5O12 film showed the best performance at a high C-rate. Because the rate-determining step of Li4Ti5O12 epitaxial thin films is inner diffusion, reinforcing the surface electric field by the deposition of a low relative permittivity materials could promote high C-rate performance even in anode materials.
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- 2021
36. Ferroelectric and ferrimagnetic properties of ε-RhxFe2−xO3 thin films
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Shintaro Yasui, Tsukasa Katayama, Mitsuru Itoh, Tomoyasu Taniyama, Takuya Osakabe, and Yosuke Hamasaki
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Crystallography ,Materials science ,Ferrimagnetism ,Materials Chemistry ,Ceramics and Composites ,General Chemistry ,Thin film ,Condensed Matter Physics ,Ferroelectricity - Published
- 2019
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37. Enhancement of Ultrahigh Rate Chargeability by Interfacial Nanodot BaTiO3 Treatment on LiCoO2 Cathode Thin Film Batteries
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Mitsuru Itoh, Shintaro Yasui, Sou Yasuhara, Tomoyasu Taniyama, Keisuke Chajima, Yutaka Majima, Takashi Teranishi, and Yumi Yoshikawa
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Fabrication ,Materials science ,business.industry ,Mechanical Engineering ,Bioengineering ,02 engineering and technology ,General Chemistry ,Dielectric ,Electrolyte ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Cathode ,law.invention ,Ion ,law ,Optoelectronics ,General Materials Science ,Nanodot ,Thin film ,0210 nano-technology ,business ,High-κ dielectric - Abstract
Nanodot BaTiO3 supported LiCoO2 cathode thin films can dramatically improve high-rate chargeability and cyclability. The prepared BaTiO3 nanodot is
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- 2019
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38. Fabrication and Characterization of Multiferroic Al0.5Fe1.5O3 Epitaxial Thin Films
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Badari Narayana Aroor Rao, Shintaro Yasui, Tsukasa Katayama, and Mitsuru Itoh
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Materials science ,Fabrication ,Mechanical Engineering ,02 engineering and technology ,Substrate (electronics) ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Ferroelectricity ,Engineering physics ,0104 chemical sciences ,Ferromagnetism ,Mechanics of Materials ,Ferrimagnetism ,Deposition (phase transition) ,General Materials Science ,Multiferroics ,Thin film ,0210 nano-technology - Abstract
Single-phase multiferroic materials have attracted considerable attention among scientists, due to the strong drive in industry towards device miniaturization, addition of new functionalities, etc. Currently, most of the discovered materials have at-least one ferroic order active only at low temperatures, thereby hindering their induction into practical devices. κ-Al2O3-type AlxFe2-xO3 (x-AFO) oxides belong to a new class of metastable multiferroic compounds (space group: Pna21), with relatively high Curie temperatures. The current work investigates the effect of thin film deposition conditions on the ferroelectric and ferrimagnetic properties of Al0.5Fe1.5O3 (0.5-AFO). Substrate temperature and oxygen partial pressure during deposition were found to be the critical parameters in obtaining high quality films. Optimizing the deposition conditions of 0.5-AFO enabled observation of both ferroelectricity and ferrimagnetism at room temperature.
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- 2019
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39. Magnetic properties of Single Crystal GaFeO3
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Shintaro Yasui, Badari Narayana Aroor Rao, Takuro Dazai, Mitsuru Itoh, Tomoyasu Taniyama, Koki Tachiyama, Tsukasa Katayama, Yosuke Hamasaki, Huan He, Hui Wang, Takamasa Usami, and Jianding Yu
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Materials science ,Mechanical Engineering ,Oxide ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Polarization (waves) ,01 natural sciences ,0104 chemical sciences ,Ion ,Crystallography ,chemistry.chemical_compound ,Octahedron ,chemistry ,Mechanics of Materials ,General Materials Science ,Multiferroics ,0210 nano-technology ,Spontaneous magnetization ,Single crystal ,Antiparallel (electronics) - Abstract
κ-Al2O3-type GaFeO3 is a promising multiferroic material due to the coexistence of a large spontaneous magnetization and polarization near room temperature. In the current study, we present the magnetic properties of single crystalline GaFeO3 and compare it with that of e-Fe2O3. Magnetic measurements revealed that spontaneous magnetization appears below 540 K in two steps, similar to that reported for e−Fe2O3. Partial magnetic ordering takes place at 540 K (TN1), with Fe3+ ions in two distorted octahedral sites ordering antiparallel to one another. Upon further cooling at 200 K (TN2), the remaining Fe3+ ions in regular octahedra and tetrahedra order antiparallel to one another. Substitution of Ga for Fe in e-Fe2O3 leads to a decrease in TN1 and TN2 from 850 to 540 K and from 480 to 200 K, respectively, caused by a dilution of magnetic Fe by nonmagnetic Ga and preferential site occupation of Ga.
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- 2019
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40. High-Rate Performance of LiCoO_2_ Epitaxial Thin Films with Various Surface Conditions
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Tomoyasu Taniyama, Shintaro Yasui, Mitsuru Itoh, and Sou Yasuhara
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Materials science ,Diffusion ,chemistry.chemical_element ,02 engineering and technology ,Electrolyte ,010402 general chemistry ,01 natural sciences ,Ion ,law.invention ,Pulsed laser deposition ,law ,General Materials Science ,Thin film ,business.industry ,Mechanical Engineering ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Cathode ,0104 chemical sciences ,chemistry ,Mechanics of Materials ,Electrode ,Optoelectronics ,Lithium ,0210 nano-technology ,business - Abstract
Lithium ion batteries with high-rate performance have been demanded since electric and hybrid vehicles are released. It is known that high interfacial resistance between electrode and electrolyte prevents intercalation of lithium ions. We investigated high-rate capability of typical LiCoO2 cathode with various surface morphologies using epitaxial thin films prepared by pulsed laser deposition. As a result, high-rate performance in (104)LiCoO2 thin films was enhanced by an increase of (110)LiCoO2 facet density because diffusion coefficient of (110)LiCoO2 was larger than that of (104)LiCoO2. Therefore, a control of crystal plane at the surface is a key point for high-rate performance.
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- 2019
41. Increasing trend in the prevalence of alcohol‐sensitive individuals with alcohol use disorder over the past 40 years
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Hiroyuki Uchida, Hideki Nakayama, Akira Yokoyama, Fumihiko Ueno, Mitsuru Itoh, Tomoko Yonemoto, Mitsuru Kimura, Sachio Matsushita, and Yosuke Yumoto
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medicine.medical_specialty ,Alcohol Drinking ,business.industry ,General Neuroscience ,MEDLINE ,Alcohol ,General Medicine ,Alcohol use disorder ,medicine.disease ,Alcoholism ,Psychiatry and Mental health ,chemistry.chemical_compound ,Neurology ,chemistry ,Prevalence ,Humans ,Medicine ,Neurology (clinical) ,business ,Psychiatry - Published
- 2021
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42. Large Polarization Switching and High-Temperature Magnetoelectric Coupling in Multiferroic GaFeO
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Hui, Wang, Yang, Zhang, Koki, Tachiyama, Zhaoyang, Xia, Jinghong, Fang, Qin, Li, Guofeng, Cheng, Yun, Shi, Jianding, Yu, Tsukasa, Katayama, Shintaro, Yasui, and Mitsuru, Itoh
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GaFeO
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- 2020
43. Large Polarization Switching and High-Temperature Magnetoelectric Coupling in Multiferroic GaFeO3 Systems
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Yun Shi, Shintaro Yasui, Koki Tachiyama, Guofeng Cheng, Jinghong Fang, Tsukasa Katayama, Haiyan Wang, Yang Zhang, Jianding Yu, Zhaoyang Xia, Mitsuru Itoh, and Qin Li
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Condensed matter physics ,010405 organic chemistry ,Chemistry ,Doping ,010402 general chemistry ,01 natural sciences ,Ferroelectricity ,0104 chemical sciences ,Inorganic Chemistry ,Crystal ,Magnetic anisotropy ,Ferrimagnetism ,Multiferroics ,Physical and Theoretical Chemistry ,Polarization (electrochemistry) ,Spontaneous magnetization - Abstract
GaFeO3-type iron oxides are promising multiferroics due to the coexistence of large spontaneous magnetization and polarization near room temperature. However, the high leakage current and difficulties associated with synthesizing single crystals make it difficult to achieve two important features in the system: a large ferroelectric polarization switching and magnetoelectric coupling at a high-temperature region. Herein, we report successful achievement of these features by preparing high-quality Sc-doped GaFeO3 single crystals (ScxGa1-x/2Fe1-x/2O3 with x = 0-0.3) using the floating zone method. The x ≥ 0.05 crystals exhibit a leakage current 104 times lower than the x = 0 crystals, highlighting the importance of Sc doping. Because of the reduced leakage current, the Sc-doped crystals exhibit large ferroelectric polarization switching along the c-axis with a remanent polarization of 22-25 μC/cm2, which is close to the theoretically predicted polarization value of 25-28 μC/cm2. In addition, the Sc-doped crystals exhibit ferrimagnetism with magnetic anisotropy along the a-axis. Furthermore, a magnetic-field-induced modulation of polarization is observed in the x = 0.15 crystal even at a relatively high temperature, i.e., 100 K.
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- 2020
44. Enhanced Spontaneous Polarization by V
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Masayuki, Fukuda, Takumi, Nishikubo, Zhao, Pan, Yuki, Sakai, Mao-Hua, Zhang, Shogo, Kawaguchi, Hongwu, Yu, Yoichi, Okimoto, Shin-Ya, Koshihara, Mitsuru, Itoh, Jürgen, Rödel, and Masaki, Azuma
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Spontaneous polarization (
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- 2020
45. Enhanced Spontaneous Polarization by V4+ Substitution in a Lead-Free Perovskite CaMnTi2O6
- Author
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Jürgen Rödel, Hongwu Yu, Yuki Sakai, Yoichi Okimoto, Shogo Kawaguchi, Masaki Azuma, Masayuki Fukuda, Mitsuru Itoh, Mao-Hua Zhang, Zhao Pan, Takumi Nishikubo, and Shin-ya Koshihara
- Subjects
Diffraction ,Chemistry ,Transition temperature ,Intermetallic ,Ferroelectricity ,Synchrotron ,law.invention ,Inorganic Chemistry ,Crystallography ,law ,Electron configuration ,Physical and Theoretical Chemistry ,Polarization (electrochemistry) ,Perovskite (structure) - Abstract
Spontaneous polarization (Ps) of novel order-disorder type lead-free ferroelectric CaMnTi2O6 was successfully enhanced by partial V4+ substitution for Ti4+. A synchrotron X-ray diffraction study revealed that the polar displacement of octahedrally coordinated (Ti, V) in CaMn(Ti1-xVx)2O6 (0 ≤ x ≤ 0.4) increases with V4+ substitution having Jahn-Teller activity owing to the d1 electronic configuration. Our magnetic study suggested the presence of antisite disorder between Ca2+ and square planar coordinated Mn2+ associated with Mn-V intermetallic charge transfer for x ≥ 0.4, resulting in decreases in spontaneous polarization and the ferroelectric-paraelectric transition temperature. This is the first report on the enhanced polarization owing to the Jahn-Teller distortion of V4+ without stereochemical Pb2+ or Bi3+.
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- 2020
46. Sizable Suppression of Thermal Hall Effect upon Isotopic Substitution in SrTiO_{3}
- Author
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Sangwoo, Sim, Heejun, Yang, Ha-Leem, Kim, Matthew J, Coak, Mitsuru, Itoh, Yukio, Noda, and Je-Geun, Park
- Abstract
We report measurements of the thermal Hall effect in single crystals of both pristine and isotopically substituted strontium titanate. We discovered a 2 orders of magnitude difference in the thermal Hall conductivity between SrTi^{16}O_{3} and ^{18}O-enriched SrTi^{18}O_{3} samples. In most temperature ranges, the magnitude of thermal Hall conductivity (κ_{xy}) in SrTi^{18}O_{3} is proportional to the magnitude of the longitudinal thermal conductivity (κ_{xx}), which suggests a phonon-mediated thermal Hall effect. However, they deviate in the temperature of their maxima, and the thermal Hall angle ratio (|κ_{xy}/κ_{xx}|) shows anomalously decreasing behavior below the ferroelectric Curie temperature T_{c}∼25 K. This observation suggests a new underlying mechanism, as the conventional scenario cannot explain such differences within the slight change in phonon spectrum. Notably, the difference in magnitude of thermal Hall conductivity and rapidly decreasing thermal Hall angle ratio in SrTi^{18}O_{3} is correlated with the strength of quantum critical fluctuations in this displacive ferroelectric. This relation points to a link between the quantum critical physics of strontium titanate and its thermal Hall effect, a possible clue to explain this example of an exotic phenomenon in nonmagnetic insulating systems.
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- 2020
47. Cation-Deficiency-Induced Crystal-Site Engineering for ZnGa
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Takuro, Dazai, Shintaro, Yasui, Tomoyasu, Taniyama, and Mitsuru, Itoh
- Abstract
Zn-deficient spinel-type ZnGa
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- 2020
48. Covalency driven modulation of paramagnetism and development of lone pair ferroelectricity in multiferroic Pb3TeMn3P2O14
- Author
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Sugata Ray, Mitsuru Itoh, Rafikul Ali Saha, Anita Halder, Tanusri Saha-Dasgupta, and Desheng Fu
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Condensed Matter::Materials Science ,Paramagnetism ,Crystallography ,Materials science ,Structural change ,Degree (graph theory) ,Charge (physics) ,Multiferroics ,Dielectric ,Lone pair ,Ferroelectricity - Abstract
We have investigated the structural, magnetic, and dielectric properties of the Pb-based langasite compound ${\mathrm{Pb}}_{3}{\mathrm{TeMn}}_{3}{\mathrm{P}}_{2}{\mathrm{O}}_{14}$ both experimentally and theoretically in light of metal-oxygen covalency, and the consequent generation of multiferroicity. It is known that the large covalency between Pb $6p$ and O $2p$ plays an instrumental role behind the stereochemical lone pair activity of Pb. The same happens here, but a subtle structural phase transition above room temperature changes the degree of such lone pair activity and the system becomes ferroelectric below 310 K. Interestingly, this structural change also modulates the charge densities on different constituent atoms and consequently the overall magnetic response of the system while maintaining the global paramagnetism behavior of the compound. This single origin of modulation in polarity and paramagnetism inherently connects both functionalities and the system exhibits mutiferroicity at room temperature.
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- 2020
- Full Text
- View/download PDF
49. Modulating the Structure and Magnetic Properties of ϵ-Fe2O3 Nanoparticles via Electrochemical Li+ Insertion
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Mitsuru Itoh, Shintaro Yasui, Maarit Karppinen, Anish Philip, Tsukasa Katayama, Yoshiyuki Inaguma, Hajime Hojo, Takahiro Ao, Yosuke Hamasaki, Sou Yasuhara, Tokyo Institute of Technology, National Defense Academy of Japan, The University of Tokyo, Gakushuin University, Kyushu University, Department of Chemistry and Materials Science, Aalto-yliopisto, and Aalto University
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Fe2o3 nanoparticles ,010405 organic chemistry ,Iron oxide ,Crystal structure ,010402 general chemistry ,Electrochemistry ,01 natural sciences ,0104 chemical sciences ,Inorganic Chemistry ,Crystallography ,chemistry.chemical_compound ,chemistry ,Magnet ,Phase (matter) ,Metastability ,Multiferroics ,Physical and Theoretical Chemistry - Abstract
ϵ-Fe2O3, a metastable phase of iron oxide, is widely known as a room-temperature multiferroic material or as a superhard magnet. Element substitution into ϵ-Fe2O3 has been reported in the literature; however, the substituted ions have a strong site preference depending on their ionic radii and valence. In this study, in order to characterize the crystal structure and magnetic properties of ϵ-Fe2O3 in the Fe2+/Fe3+ coexisting states, Li+ was electrochemically inserted into ϵ-Fe2O3 to reduce Fe3+. The discharge and charge of Li+ into/from ϵ-Fe2O3 revealed that Li+ insertion was successful. X-ray magnetic circular dichroism results indicated that the reduced Fe did not exhibit site preference. Increasing the Li+ content in ϵ-Fe2O3 resulted in decreased saturation magnetization and irregular variation of the coercive field. We present a comprehensive discussion of how magnetic properties are modified with increasing Li+ content using transmission electron microscopy images and considering the Li+ diffusion coefficient. The results suggest that inserting Li+ into crystalline ϵ-Fe2O3 is a useful tool for characterizing crystal structure, lithiation limit, and magnetic properties in the coexistence of Fe2+/Fe3+
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- 2020
50. Risk factors and appropriate therapeutic strategies for thrombotic microangiopathy after allogeneic HSCT
- Author
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Kazuyo Yamamoto, Kazuhiro Yago, Junya Kanda, Yasuyuki Arai, Takayuki Ishikawa, Hiroharu Imoto, Mitsuru Itoh, Akifumi Takaori-Kondo, Hiroko Tsunemine, Masaharu Nohgawa, Yasunori Ueda, Yusuke Toda, Akihito Yonezawa, Takaya Mitsuyoshi, Naoyuki Anzai, Naoki Tamura, Kazunori Imada, Masaaki Tsuji, Tadakazu Kondo, Toshinori Moriguchi, and Hiroyuki Matsui
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medicine.medical_specialty ,Transplantation ,Thrombotic microangiopathy ,Performance status ,business.industry ,Thrombotic Microangiopathies ,medicine.medical_treatment ,Hazard ratio ,Hematopoietic Stem Cell Transplantation ,Retrospective cohort study ,Hematology ,Hematopoietic stem cell transplantation ,medicine.disease ,Calcineurin ,Cohort Studies ,Risk Factors ,Internal medicine ,Cohort ,medicine ,Humans ,business ,Aged ,Retrospective Studies - Abstract
Transplant-associated thrombotic microangiopathy (TA-TMA) is a fatal complication of allogeneic hematopoietic stem cell transplantation (allo-HSCT). However, so far, no large cohort study determined the risk factors and the most effective therapeutic strategies for TA-TMA. Thus, the present study aimed to clarify these clinical aspects based on a large multicenter cohort. This retrospective cohort study was performed by the Kyoto Stem Cell Transplantation Group (KSCTG). A total of 2425 patients were enrolled from 14 institutions. All patients were aged ≥16 years, presented with hematological diseases, and received allo-HSCT after the year 2000. TA-TMA was observed in 121 patients (5.0%) on day 35 (median) and was clearly correlated with inferior overall survival (OS) (hazard ratio [HR], 4.93). Pre- and post-HSCT statistically significant risk factors identified by multivariate analyses included poorer performance status (HR, 1.69), HLA mismatch (HR, 2.17), acute graft-versus-host disease (aGVHD; grades 3-4) (HR, 4.02), Aspergillus infection (HR, 2.29), and veno-occlusive disease/sinusoidal obstruction syndrome (VOD/SOS; HR, 4.47). The response rate and OS significantly better with the continuation or careful reduction of calcineurin inhibitors (CNI) than the conventional treatment strategy of switching from CNI to corticosteroids (response rate, 64.7% vs 20.0%). In summary, we identified the risk factors and the most appropriate therapeutic strategies for TA-TMA. The described treatment strategy could improve the outcomes of patients with TA-TMA in the future.
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- 2020
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