308 results on '"R. Arita"'
Search Results
2. Observation of anomalous Hall resonance of massive Dirac fermions in topological kagome-lattice magnet
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Y. Okamura, K. Shoriki, Y. Nomura, Y. Fujishiro, A. Kitaori, N. Kanazawa, R. Arita, Y. Tokura, and Y. Takahashi
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Materials of engineering and construction. Mechanics of materials ,TA401-492 ,Atomic physics. Constitution and properties of matter ,QC170-197 - Abstract
Abstract The kagome-lattice materials promise emergence of Dirac fermions thanks to the special lattice geometry, which potentially realizes intriguing quantum topological states through various many-body interactions. The low-energy electromagnetic phenomena arising from such the Dirac fermions are expected to show the remarkable enhancement and, in certain conditions, to approach the universal responses, which, however, have remained elusive experimentally. Here, we show the resonantly enhanced magneto-optical response of massive Dirac fermions in kagome-lattice magnet TbMn6Sn6. The infrared magneto-optical spectroscopy reveals that the interband transition on massive Dirac bands significantly contributes to the observed resonance in the optical Hall conductivity. The analytical model expressed by a few band parameters reproduces the spectral characteristics of the resonance, which robustly produces almost 20 % of the quantized Hall conductance per one kagome layer even at room temperature. Our findings establish the general optical response of massive Dirac fermions, which is closely related to the universal electrodynamics in quantum anomalous Hall state.
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- 2023
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3. Field-induced multiple metal-insulator crossovers of correlated Dirac electrons of perovskite CaIrO3
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R. Yamada, J. Fujioka, M. Kawamura, S. Sakai, M. Hirayama, R. Arita, T. Okawa, D. Hashizume, T. Sato, F. Kagawa, R. Kurihara, M. Tokunaga, and Y. Tokura
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Materials of engineering and construction. Mechanics of materials ,TA401-492 ,Atomic physics. Constitution and properties of matter ,QC170-197 - Abstract
Abstract The interplay between electron correlation and topology of relativistic electrons may lead to a fascinating stage of the research on quantum materials and emergent functions. The emergence of various collective electronic orderings/liquids, which are tunable by external stimuli, is a remarkable feature of correlated electron systems, but has rarely been realized in the topological semimetals with high-mobility relativistic electrons. Here, we report that the correlated Dirac electrons in perovskite CaIrO3 show unconventional field-induced successive metal–insulator–metal crossovers in the quantum limit accompanying a giant magnetoresistance (MR) with MR ratio of 3500 % (18 T and 1.4 K). In conjunction with the numerical calculation, we propose that the insulating state originates from the collective electronic ordering such as charge/spin density wave promoted by electron correlation, whereas it turns into the quasi-one-dimensional metal at higher fields due to the field-induced reduction of chemical potential, highlighting the highly field-tunable character of correlated Dirac electrons.
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- 2022
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4. Magneto-optical spectroscopy on Weyl nodes for anomalous and topological Hall effects in chiral MnGe
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Y. Hayashi, Y. Okamura, N. Kanazawa, T. Yu, T. Koretsune, R. Arita, A. Tsukazaki, M. Ichikawa, M. Kawasaki, Y. Tokura, and Y. Takahashi
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Science - Abstract
Previous work has proposed that the anomalous and topological Hall effects, associated with Weyl nodes, should have a signature in optical conductivity. Here, using THz optical spectroscopy, the authors assign these two effects to optical conductivity resonances, arising near band anti-crossings, in thin films of MnGe.
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- 2021
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5. Giant magneto-optical responses in magnetic Weyl semimetal Co3Sn2S2
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Y. Okamura, S. Minami, Y. Kato, Y. Fujishiro, Y. Kaneko, J. Ikeda, J. Muramoto, R. Kaneko, K. Ueda, V. Kocsis, N. Kanazawa, Y. Taguchi, T. Koretsune, K. Fujiwara, A. Tsukazaki, R. Arita, Y. Tokura, and Y. Takahashi
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Science - Abstract
The evidence of topological origin for the recently observed anomalous Hall effect remains elusive. Here, the authors report that the resonance of the optical Hall conductivity resulted from topological electronic structure gives rise to the large intrinsic anomalous Hall effect in the magnetic Weyl semimetal Co3Sn2S2.
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- 2020
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6. Devil's staircase transition of the electronic structures in CeSb
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Kenta Kuroda, Y. Arai, N. Rezaei, S. Kunisada, S. Sakuragi, M. Alaei, Y. Kinoshita, C. Bareille, R. Noguchi, M. Nakayama, S. Akebi, M. Sakano, K. Kawaguchi, M. Arita, S. Ideta, K. Tanaka, H. Kitazawa, K. Okazaki, M. Tokunaga, Y. Haga, S. Shin, H. S. Suzuki, R. Arita, and Takeshi Kondo
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Science - Abstract
CeSb undergoes a devil’s staircase sequence of extremely long-period modulations of the magnetically ordered 4f states. Here, the authors visualize how the devil’s staircase ordering impacts mobile electrons and collapses the well-defined band picture at the Fermi energy.
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- 2020
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7. Topological transitions among skyrmion- and hedgehog-lattice states in cubic chiral magnets
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Y. Fujishiro, N. Kanazawa, T. Nakajima, X. Z. Yu, K. Ohishi, Y. Kawamura, K. Kakurai, T. Arima, H. Mitamura, A. Miyake, K. Akiba, M. Tokunaga, A. Matsuo, K. Kindo, T. Koretsune, R. Arita, and Y. Tokura
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Science - Abstract
Manipulating topological spin textures are demanded for future spintronic devices, but knowledge about phase transitions among different spin textures remain limited. Here, Fujishiro and Kanazawa et al. report chemical-pressure-controlled phase transitions between different topological spin textures in chiral magnets MnSi1−x Ge x .
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- 2019
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8. Strong-correlation induced high-mobility electrons in Dirac semimetal of perovskite oxide
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J. Fujioka, R. Yamada, M. Kawamura, S. Sakai, M. Hirayama, R. Arita, T. Okawa, D. Hashizume, M. Hoshino, and Y. Tokura
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Science - Abstract
Electron correlation normally makes electrons less mobile, but it is still not clear when correlation becomes very strong in Dirac semimetals. Here, Fujioka et al. report a very high electron mobility exceeding 60,000 cm2V−1s−1 in correlated Dirac semimetal of perovskite CaIrO3, due to the enhanced electron correlation nearby the Mott transition.
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- 2019
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9. Large magneto-thermopower in MnGe with topological spin texture
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Y. Fujishiro, N. Kanazawa, T. Shimojima, A. Nakamura, K. Ishizaka, T. Koretsune, R. Arita, A. Miyake, H. Mitamura, K. Akiba, M. Tokunaga, J. Shiogai, S. Kimura, S. Awaji, A. Tsukazaki, A. Kikkawa, Y. Taguchi, and Y. Tokura
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Science - Abstract
Topological spin textures produce versatile electronic functionalities, but are scarcely exploited for achieving heat to electricity conversion. Here, Fujishiro et al. attribute an enhanced magneto-thermopower in MnGe with topological spin hedgehogs, to electron scattering via the dynamics of an emergent magnetic field.
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- 2018
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10. Tuning the Parity Mixing of Singlet-Septet Pairing in a Half-Heusler Superconductor
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K. Ishihara, T. Takenaka, Y. Miao, Y. Mizukami, K. Hashimoto, M. Yamashita, M. Konczykowski, R. Masuki, M. Hirayama, T. Nomoto, R. Arita, O. Pavlosiuk, P. Wiśniewski, D. Kaczorowski, and T. Shibauchi
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Physics ,QC1-999 - Abstract
In superconductors, electrons with spin s=1/2 form Cooper pairs whose spin structure is usually singlet (S=0) or triplet (S=1). When the electronic structure near the Fermi level is characterized by fermions with angular momentum j=3/2 due to strong spin-orbit interactions, novel pairing states such as even-parity quintet (J=2) and odd-parity septet (J=3) states are allowed. Prime candidates for such exotic states are half-Heusler superconductors, which exhibit unconventional superconducting properties, but their pairing nature remains unsettled. Here, we show that the superconductivity in the noncentrosymmetric half-Heusler LuPdBi can be consistently described by the admixture of isotropic even-parity singlet and anisotropic odd-parity septet pairing, whose ratio can be tuned by electron irradiation. From magnetotransport and penetration depth measurements, we find that carrier concentrations and impurity scattering both increase with irradiation, resulting in a nonmonotonic change of the superconducting gap structure. Our findings shed new light on our fundamental understanding of unconventional superconducting states in topological materials.
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- 2021
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11. Benchmark for Ab Initio Prediction of Magnetic Structures Based on Cluster-Multipole Theory
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M.-T. Huebsch, T. Nomoto, M.-T. Suzuki, and R. Arita
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Physics ,QC1-999 - Abstract
The cluster-multipole (CMP) expansion for magnetic structures provides a scheme to systematically generate candidate magnetic structures specifically including noncollinear magnetic configurations adapted to the crystal symmetry of a given material. A comparison with the experimental data collected on MAGNDATA shows that the most stable magnetic configurations in nature are linear combinations of only few CMPs. Furthermore, a high-throughput calculation for all candidate magnetic structures is performed in the framework of spin-density functional theory (SDFT). We benchmark the predictive power of CMP+SDFT with 2935 calculations, which show that (i) the CMP expansion administers an exhaustive list of candidate magnetic structures, (ii) CMP+SDFT can narrow down the possible magnetic configurations to a handful of computed configurations, and (iii) SDFT reproduces the experimental magnetic configurations with an accuracy of ±0.5μ_{B}. For a subset the impact of on-site Coulomb repulsion U is investigated by means of 1545 CMP+SDFT+U calculations revealing no further improvement on the predictive power.
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- 2021
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12. Quantum oscillations in the centrosymmetric skyrmion-hosting magnet GdRu2Si2
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N. Matsuyama, T. Nomura, S. Imajo, T. Nomoto, R. Arita, K. Sudo, M. Kimata, N. D. Khanh, R. Takagi, Y. Tokura, S. Seki, K. Kindo, and Y. Kohama
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- 2023
13. Spontaneous topological Hall effect induced by non-coplanar antiferromagnetic order in intercalated van der Waals materials
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H. Takagi, R. Takagi, S. Minami, T. Nomoto, K. Ohishi, M.-T. Suzuki, Y. Yanagi, M. Hirayama, N. D. Khanh, K. Karube, H. Saito, D. Hashizume, R. Kiyanagi, Y. Tokura, R. Arita, T. Nakajima, and S. Seki
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Condensed Matter - Materials Science ,Condensed Matter - Strongly Correlated Electrons ,Strongly Correlated Electrons (cond-mat.str-el) ,General Physics and Astronomy ,Materials Science (cond-mat.mtrl-sci) ,FOS: Physical sciences - Abstract
In ferromagnets, electric current generally induces transverse Hall voltage in proportion to magnetization (anomalous Hall effect), and it is frequently used for electrical readout of the up and down spin states. While these properties are usually not expected in antiferromagnets, recent theoretical studies predicted that non-coplanar antiferromagnetic order with finite scalar spin chirality (i.e. solid angle spanned by neighboring spins) can often induce large spontaneous Hall effect even without net magnetization or external magnetic field. This phenomenon, i.e. spontaneous topological Hall effect, can potentially be used for the efficient electrical readout of the antiferromagnetic states, but its experimental verification has long been elusive due to the lack of appropriate materials hosting such exotic magnetism. Here, we report the discovery of all-in-all-out type non-coplanar antiferromagnetic order in triangular lattice compounds CoTa3S6 and CoNb3S6, by performing the detailed magnetic structure analysis based on polarized neutron scattering experiments as well as systematic first-principles calculations. These compounds are reported to host unconventionally large spontaneous Hall effect despite their vanishingly small net magnetization, and our analysis revealed that it can be well explained in terms of topological Hall effect, which originates from the fictitious magnetic field associated with scalar spin chirality in non-coplanar antiferromagnetic orders. The present results indicate that the scalar spin chirality mechanism can offer a promising route to realize giant spontaneous Hall response even in compensated antiferromagnets, and highlight intercalated van der Waals magnets as an unique quasi-two-dimensional material platform to enable various nontrivial manner of electrical reading and possible writing of non-coplanar antiferromagnetic domains., Comment: to appear in Nature Physics
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- 2023
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14. Magnetic structures and electronic properties of cubic-pyrochlore ruthenates from first principles
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M-T Huebsch, Y Nomura, S Sakai, and R Arita
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Condensed Matter - Strongly Correlated Electrons ,Condensed Matter - Materials Science ,Strongly Correlated Electrons (cond-mat.str-el) ,Materials Science (cond-mat.mtrl-sci) ,FOS: Physical sciences ,General Materials Science ,Condensed Matter Physics - Abstract
The magnetic ground states of $R_2$Ru$_2$O$_7$ and $A_2$Ru$_2$O$_7$ with $R=$ Pr, Gd, Ho, and Er, as well as $A=$ Ca, Cd are predicted devising a combination of the cluster-multipole (CMP) theory and spin-density-functional theory (SDFT). The strong electronic correlation effects are estimated by the constrained-random-phase approximation (cRPA) and taken into account within the dynamical-mean-field theory (DMFT). The target compounds feature $d$-orbital magnetism on Ru$^{4+}$ and Ru$^{5+}$ ions for $R$ and $A$, respectively, as well as $f$-orbital magnetism on the $R$ site, which leads to an intriguing interplay of magnetic interactions in a strongly correlated system. We find CMP+SDFT is capable of describing the magnetic ground states in these compounds. The cRPA captures a difference in the screening strength between $R_2$Ru$_2$O$_7$ and $A_2$Ru$_2$O$_7$ compounds, which leads to a qualitative and quantitative understanding of the electronic properties within DMFT., Comment: 15 pages, 5 figures, 5 tables
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- 2021
15. Multipole polaron in the devil's staircase of CeSb
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Y. Arai, Kenta Kuroda, T. Nomoto, Z. H. Tin, S. Sakuragi, C. Bareille, S. Akebi, K. Kurokawa, Y. Kinoshita, W.-L. Zhang, S. Shin, M. Tokunaga, H. Kitazawa, Y. Haga, H. S. Suzuki, S. Miyasaka, S. Tajima, K. Iwasa, R. Arita, and Takeshi Kondo
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Condensed Matter - Materials Science ,Mechanics of Materials ,Mechanical Engineering ,Materials Science (cond-mat.mtrl-sci) ,FOS: Physical sciences ,General Materials Science ,General Chemistry ,Condensed Matter Physics - Abstract
Rare-earth intermetallic compounds exhibit rich phenomena induced by the interplay between localized $f$ orbitals and conduction electrons. However, since the energy scale of the crystal-electric-field splitting is only a few millielectronvolts, the nature of the mobile electrons accompanied by collective crystal-electric-field excitations has not been unveiled. Here, we examine the low-energy electronic structures of CeSb through the anomalous magnetostructural transitions below the N$\'{e}$el temperature, $\sim$17 K, termed the 'devil's staircase', using laser angle-resolved photoemission, Raman and neutron scattering spectroscopies. We report another type of electron-boson coupling between mobile electrons and quadrupole crystal-electric-field excitations of the 4$f$ orbitals, which renormalizes the Sb 5$p$ band prominently, yielding a kink at a very low energy ($\sim$7 meV). This coupling strength is strong and exhibits anomalous step-like enhancement during the devil's staircase transition, unveiling a new type of quasiparticle, named the 'multipole polaron', comprising a mobile electron dressed with a cloud of the quadrupole crystal-electric-field polarization., Comment: 21 pages, 4 figures
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- 2021
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16. Topological Kagome Magnet Co
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M, Tanaka, Y, Fujishiro, M, Mogi, Y, Kaneko, T, Yokosawa, N, Kanazawa, S, Minami, T, Koretsune, R, Arita, S, Tarucha, M, Yamamoto, and Y, Tokura
- Abstract
Magnetic Weyl semimetals attract considerable interest not only for their topological quantum phenomena but also as an emerging materials class for realizing quantum anomalous Hall effect in the two-dimensional limit. A shandite compound Co
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- 2020
17. Multipole polaron in the devil's staircase of CeSb
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Y, Arai, Kenta, Kuroda, T, Nomoto, Z H, Tin, S, Sakuragi, C, Bareille, S, Akebi, K, Kurokawa, Y, Kinoshita, W-L, Zhang, S, Shin, M, Tokunaga, H, Kitazawa, Y, Haga, H S, Suzuki, S, Miyasaka, S, Tajima, K, Iwasa, R, Arita, and Takeshi, Kondo
- Abstract
Rare-earth intermetallic compounds exhibit rich phenomena induced by the interplay between localized f orbitals and conduction electrons. However, since the energy scale of the crystal-electric-field splitting is only a few millielectronvolts, the nature of the mobile electrons accompanied by collective crystal-electric-field excitations has not been unveiled. Here, we examine the low-energy electronic structures of CeSb through the anomalous magnetostructural transitions below the Néel temperature, ~17 K, termed the 'devil's staircase', using laser angle-resolved photoemission, Raman and neutron scattering spectroscopies. We report another type of electron-boson coupling between mobile electrons and quadrupole crystal-electric-field excitations of the 4f orbitals, which renormalizes the Sb 5p band prominently, yielding a kink at a very low energy (~7 meV). This coupling strength is strong and exhibits anomalous step-like enhancement during the devil's staircase transition, unveiling a new type of quasiparticle, named the 'multipole polaron', comprising a mobile electron dressed with a cloud of the quadrupole crystal-electric-field polarization.
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- 2020
18. Multiple
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R, Takagi, J S, White, S, Hayami, R, Arita, D, Honecker, H M, Rønnow, Y, Tokura, and S, Seki
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Physics::Atomic and Molecular Clusters ,Physics::Optics ,SciAdv r-articles ,Condensed Matter::Strongly Correlated Electrons ,Condensed Matter Physics ,Research Articles ,Research Article - Abstract
Neutron-scattering experiments reveal a hexagonally crystallized form of noncollinear magnetic order in an itinerant magnet., Multiple-q spin order, i.e., a spin texture characterized by a multiple number of coexisting magnetic modulation vectors q, has recently attracted attention as a source of nontrivial magnetic topology and associated emergent phenomena. One typical example is the triple-q skyrmion lattice state stabilized by Dzyaloshinskii-Moriya interactions in noncentrosymmetric magnets, while the emergence of various multiple-q states of different origins is expected according to the latest theories. Here, we investigated the magnetic structure of the itinerant polar hexagonal magnet Y3Co8Sn4, in which several distinctive mechanisms favoring multiple-q states are allowed to become active. Small-angle neutron-scattering experiments suggest the formation of incommensurate triple-q magnetic order with an in-plane vortex-like spin texture, which can be most consistently explained in terms of the novel four-spin interaction mechanism inherent to itinerant magnets. The present results suggest a new route to realizing exotic multiple-q orders and that itinerant hexagonal magnets, including the R3M8Sn4 family with wide chemical tunability, can be a unique material platform to explore their rich phase diagrams.
- Published
- 2018
19. Orbital-Dependent Band Narrowing Revealed in an Extremely Correlated Hund's Metal Emerging on the Topmost Layer of Sr_{2}RuO_{4}
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Takeshi, Kondo, M, Ochi, M, Nakayama, H, Taniguchi, S, Akebi, K, Kuroda, M, Arita, S, Sakai, H, Namatame, M, Taniguchi, Y, Maeno, R, Arita, and S, Shin
- Abstract
We use a surface-selective angle-resolved photoemission spectroscopy and unveil the electronic nature on the topmost layer of Sr_{2}RuO_{4} crystal, consisting of slightly rotated RuO_{6} octahedrons. The γ band derived from the 4d_{xy} orbital is found to be about three times narrower than that for the bulk. This strongly contrasts with a subtle variation seen in the α and β bands derived from the one-dimensional 4d_{xz/yz}. This anomaly is reproduced by the dynamical mean-field theory calculations, introducing not only the on-site Hubbard interaction but also the significant Hund's coupling. We detect a coherence-to-incoherence crossover theoretically predicted for Hund's metals, which has been recognized only recently. The crossover temperature in the surface is about half that of the bulk, indicating that the naturally generated monolayer of reconstructed Sr_{2}RuO_{4} is extremely correlated and well isolated from the underlying crystal.
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- 2016
20. Valley-dependent spin polarization in bulk MoS 2 with broken inversion symmetry
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R Suzuki, M Sakano, Y J Zhang, R Akashi, D Morikawa, A Harasawa, K Yaji, K Kuroda, K Miyamoto, T Okuda, K Ishizaka, R Arita, and Y Iwasa
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- 2014
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21. Ab initio studies on the interplay between spin-orbit interaction and Coulomb correlation in Sr2IrO4 and Ba2IrO4
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R, Arita, J, Kuneš, A V, Kozhevnikov, A G, Eguiluz, and M, Imada
- Abstract
Ab initio analyses of A(2)IrO(4) (A=Sr,Ba) are presented. Effective Hubbard-type models for Ir 5d t(2g) manifolds downfolded from the global band structure are solved based on the dynamical mean-field theory. The results for A=Sr and Ba correctly reproduce paramagnetic metals undergoing continuous transitions to insulators below the Néel temperature T(N). These compounds are classified not into Mott insulators but into Slater insulators. However, the insulating gap opens by a synergy of the Néel order and significant band renormalization, which is also manifested by a 2D bad metallic behavior in the paramagnetic phase near the quantum criticality.
- Published
- 2011
22. Two-dimensional and three-dimensional Fermi surfaces of superconducting BaFe2(As(1-x)P(x))2 and their nesting properties revealed by angle-resolved photoemission spectroscopy
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T, Yoshida, I, Nishi, S, Ideta, A, Fujimori, M, Kubota, K, Ono, S, Kasahara, T, Shibauchi, T, Terashima, Y, Matsuda, H, Ikeda, and R, Arita
- Abstract
We have studied the three-dimensional shapes of the Fermi surfaces (FSs) of BaFe(2)(As(1-x)P(x))(2) (x=0.38), where superconductivity is induced by isovalent P substitution and by angle-resolved photoemission spectroscopy. Moderately strong electron mass enhancement has been identified for both the electron and hole FSs. Among two observed hole FSs, the nearly two-dimensional one shows good nesting with the outer two-dimensional electron FS, but its orbital character is different from the outer electron FS. The three-dimensional hole FS shows poor nesting with the electron FSs. The present results suggest that the three dimensionality and the difference in the orbital character weaken FS nesting while partial nesting among the outer electron FSs of d(xy) character and/or that within the three-dimensional hole FS becomes dominant, which may lead to the nodal superconductivity.
- Published
- 2010
23. Pseudogap of metallic layered nickelate R(2-x)Sr(x)NiO4 (R = Nd, Eu) crystals measured using angle-resolved photoemission spectroscopy
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M, Uchida, K, Ishizaka, P, Hansmann, Y, Kaneko, Y, Ishida, X, Yang, R, Kumai, A, Toschi, Y, Onose, R, Arita, K, Held, O K, Andersen, S, Shin, and Y, Tokura
- Abstract
We have investigated charge dynamics and electronic structures for single crystals of metallic layered nickelates, R(2-x)Sr(x)NiO4 (R = Nd, Eu), isostructural to La(2-x)Sr(x)CuO4. Angle-resolved photoemission spectroscopy on the barely metallic Eu(0.9)Sr(1.1)NiO4 (R = Eu, x = 1.1) has revealed a large hole surface of x2-y2 character with a high-energy pseudogap of the same symmetry and comparable magnitude with those of underdoped (x0.1) cuprates, although the antiferromagnetic interactions are 1 order of magnitude smaller. This finding strongly indicates that the momentum-dependent pseudogap feature in the layered nickelate arises from the real-space charge correlation.
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- 2010
24. Doped Mott insulator as the origin of heavy-fermion behavior in LiV2O4
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R, Arita, K, Held, A V, Lukoyanov, and V I, Anisimov
- Abstract
We investigate the electronic structure of LiV2O4, for which heavy-fermion behavior has been observed in various experiments, by the combination of the local density approximation and dynamical mean field theory. To obtain results at zero temperature, we employ the projective quantum Monte Carlo method as an impurity solver. Our results show that the strongly correlated a 1g band is a lightly doped Mott insulator which, at low temperatures, shows a sharp (heavy) quasiparticle peak just above the Fermi level, which is consistent with recent photoemission experiments by Shimoyamada et al. [Phys. Rev. Lett. 96, 026403 (2006)10.1103/PhysRevLett.96.026403].
- Published
- 2007
25. Eyes dry? Try a cup of Joe
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R., Arita, Y., Yanagi, and N., Honda
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Dry eye syndromes -- Care and treatment ,Caffeine -- Health aspects ,Health - Abstract
Caffeine could offer some relief for those who suffer with dry eye syndrome--in particular a subset of people with genetic variations in two genes, Japanese researchers say. Apart from knowing [...]
- Published
- 2012
26. [The role of nurses at the open-system hospital and coordination with regional facilities]
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R, Arita and H, Miyazaki
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Male ,Humans ,Middle Aged ,Community Health Nursing ,Tokyo ,Home Care Services ,Community-Institutional Relations - Published
- 1985
27. [Absorption of drugs in digestive system and dynamics of drugs in the body]
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R, Arita
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Intestinal Absorption ,Humans ,Digestive System ,Anti-Bacterial Agents - Published
- 1982
28. [Pain: a case report]
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R, Arita
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Humans ,Antineoplastic Agents ,Middle Aged ,Pain, Intractable ,Plasmacytoma - Published
- 1980
29. Magnetic order of Nd5Pb3 single crystals.
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J-Q Yan, M Ochi, H B Cao, B Saparov, J-G Cheng, Y Uwatoko, R Arita, B C Sales, and D G Mandrus
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- 2018
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30. Superconductivity in CuxIrTe2 driven by interlayer hybridization.
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M. Kamitani, M. S. Bahramy, R. Arita, S. Seki, T. Arima, Y. Tokura, and S. Ishiwata
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SUPERCONDUCTIVITY , *ELECTRONIC structure , *HYBRID materials , *THERMOELECTRIC power , *CLATHRATE compounds , *ELECTRONS - Abstract
The change in the electronic structure of layered CuxIrTe2 has been characterized by transport and spectroscopic measurements, combined with first-principles calculations. The Cu intercalation suppresses the monoclinic distortion, giving rise to the stabilization of the trigonal phase with superconductivity. Thermopower and Hall resistivity measurements suggest the multiband nature with hole and electron carriers for this system, which is masked by the predominance of the hole carriers enhanced by the interlayer hybridization in the trigonal phase. Rather than the instability of the Ir d band, a subtle balance between the interlayer and intralayer Te-Te hybridizations is proposed as a main factor dominating the structural transition and the superconductivity. [ABSTRACT FROM AUTHOR]
- Published
- 2013
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31. Meibomian Gland Alterations With Antiglaucoma Eye Drops.
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R, Arita, I, Kouzo, S, Maeda, and K, Maeda
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MEIBOMIAN glands , *EYE drops , *GLAUCOMA treatment - Abstract
The article discusses a research paper in Japan which found that meibomian gland morphology and function are altered by the long-term use of antiglaucoma eye drops.
- Published
- 2012
32. Sequential Sampling of the Gastrointestinal Tract to Characterize the Entire Digestive Microbiome in Japanese Subjects.
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Ishizawa K, Tamahara T, Suzuki S, Hatayama Y, Li B, Abe M, Aoki Y, Arita R, Saito N, Ohsawa M, Kaneko S, Ono R, Takayama S, Shimada M, Kumada K, Koike T, Masamune A, Onodera K, Ishii T, Shimizu R, and Kanno T
- Abstract
The gastrointestinal (GI) tract harbors trillions of microorganisms known to influence human health and disease, and next-generation sequencing (NGS) now enables the in-depth analysis of their diversity and functions. Although a significant amount of research has been conducted on the GI microbiome, comprehensive metagenomic datasets covering the entire tract are scarce due to cost and technical challenges. Despite the widespread use of fecal samples, integrated datasets encompassing the entire digestive process, beginning at the mouth and ending with feces, are lacking. With this study, we aimed to fill this gap by analyzing the complete metagenome of the GI tract, providing insights into the dynamics of the microbiota and potential therapeutic avenues. In this study, we delved into the complex world of the GI microbiota, which we examined in five healthy Japanese subjects. While samples from the whole GI flora and fecal samples provided sufficient bacteria, samples obtained from the stomach and duodenum posed a challenge. Using a principal coordinate analysis (PCoA), clear clustering patterns were identified; these revealed significant diversity in the duodenum. Although this study was limited by its small sample size, the flora in the overall GI tract showed unwavering consistency, while the duodenum exhibited unprecedented phylogenetic diversity. A visual heat map illustrates the discrepancy in abundance, with Fusobacteria and Bacilli dominating the upper GI tract and Clostridia and Bacteroidia dominating the fecal samples. Negativicutes and Actinobacteria were found throughout the digestive tract. This study demonstrates that it is possible to continuously collect microbiome samples throughout the human digestive tract. These findings not only shed light on the complexity of GI microbiota but also provide a basis for future research.
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- 2024
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33. Safety and Efficacy of Photocatalytic Micro-Mist Desktop Humidifier for Dry Eye Caused by Digital Environment: A Randomized Controlled Trial.
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Arita R and Fukuoka S
- Abstract
Background/Objectives : Modern life is inconceivable without visual display terminal (VDT) work, including smartphones, computers, and games for both children and adults. VDT work under air conditioning and low humidity poses a high risk of dry eye and digital eye strain. Methods : Thirty-one participants were randomly divided into two groups using a desktop humidifier with photocatalytic technology, namely the "with mist" (humidifier) group and "without mist" (control) group. Participants performed VDT tasks using the humidifier with or without mist for 1 h. Ocular subjective symptoms and objective tear film parameters were assessed before, immediately after, and 1.5 h after the VDT task with or without mist. (Registry ID: UMIN000054379) Results : Ocular symptom scores improved significantly in the humidifier group immediately after the VDT task and up to 1.5 h later compared to before the task ( p < 0.001, =0.006, respectively). Immediately after the VDT task, tear meniscus height was significantly higher and non-invasive breakup time was significantly longer in the humidifier group than in the control group ( p < 0.001, =0.040, respectively). Plugging of the meibomian gland orifices was significantly reduced only in the humidifier group immediately after the VDT task compared to before the VDT task and remained significantly reduced up to 1.5 h later ( p = 0.004, 0.016, respectively). Conclusions : The use of the photocatalytic desktop humidifier during VDT task resulted in significant improvements in the tear film parameters and subjective symptoms. The photocatalytic desktop humidifier could be effective in alleviating dry eye and eye strain in computer users in a modern office environment.
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- 2024
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34. Comparison of Intense Pulsed Light Treatments including Upper Lid or Lateral Canthus in Patients of Meibomian Gland Dysfunction.
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Min JS, Jun I, Kim TI, Arita R, and Seo KY
- Abstract
Background: To determine the differences in the effects of intense pulsed light (IPL) treatment when including the upper and lower lid or lateral canthus area in patients with meibomian gland dysfunction (MGD). Methods: Patients who underwent three IPL treatment sessions at 3-week intervals were divided into three groups according to the treatment sites: group A, lower lid; group B, upper and lower lids; and group C, lower lid and lateral canthal area. Before and after the IPL treatment sessions, we obtained the lid abnormality score (LAS), meibum expressibility (ME), meibum quality (MQ), lipid layer thickness (LLT), type I Schirmer test (ST), tear break-up time (TBUT) test, corneal fluorescein staining scores (CFSs), and Ocular Surface Disease Index (OSDI). Results: IPL treatment significantly improved LASs, ME, MQ, TBUT, CFS, and OSDI values in all groups. Differences in LAS values before and after IPL treatment were significantly greater in groups B and C than those in group A. Conclusions: IPL treatment encompassing the upper lid and lateral canthus together with the lower lid elicited additional improvement in patients with MGD. The additional effect on treating the lateral canthus was similar to the effect observed on the additional treatment of the upper lid.
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- 2024
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35. Oral alkalinizing supplementation suppressed intrarenal reactive oxidative stress in mild-stage chronic kidney disease: a randomized cohort study.
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Abe M, Yamaguchi T, Koshiba S, Takayama S, Nakai T, Nishioka K, Yamasaki S, Kawaguchi K, Umeyama M, Masaura A, Ishizawa K, Arita R, Kanno T, Akaishi T, Miyazaki M, Abe T, Tanaka T, and Ishii T
- Abstract
Background: The beneficial effects of oral supplements with alkalinizing agents in patients with chronic kidney disease (CKD) have been limited to the severe stages. We investigated whether two types of supplements, sodium bicarbonate (SB) and potassium citrate/sodium citrate (PCSC), could maintain renal function in patients with mild-stage CKD., Methods: This was a single-center, open-labeled, randomized cohort trial. Study participants with CKD stages G2, G3a, and G3b were enrolled between March 2013 and January 2019 and randomly assigned by stratification according to age, sex, estimated glomerular filtration rate (eGFR), and diabetes. They were followed up for 6 months (short-term study) for the primary endpoints and extended to 2 years (long-term study) for the secondary endpoints. Supplementary doses were adjusted to achieve an early morning urinary pH of 6.8-7.2. We observed renal dysfunction or new-onset cerebrovascular disease and evaluated urinary surrogate markers for renal injury., Results: Overall, 101 participants were registered and allocated to three groups: standard (n = 32), SB (n = 34), and PCSC (n = 35). Two patients in the standard group attained the primary endpoints (renal stones and overt proteinuria) but were not statistically significant. There was one patient in the standard reduced eGFR during the long-term study (p = 0.042 by ANOVA). SB increased proteinuria (p = 0.0139, baseline vs. 6 months), whereas PCSC significantly reduced proteinuria (p = 0.0061, baseline vs. 1 year, or p = 0.0186, vs. 2 years) and urinary excretion of 8-hydroxy-2'-deoxyguanosine (p = 0.0481, baseline vs. 6 months)., Conclusion: This study is the first to report supplementation of PCSC reduced intrarenal oxidative stress in patients with mild-stage CKD., (© 2024. The Author(s).)
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- 2024
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36. Current-driven fast magnetic octupole domain-wall motion in noncollinear antiferromagnets.
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Wu M, Chen T, Nomoto T, Tserkovnyak Y, Isshiki H, Nakatani Y, Higo T, Tomita T, Kondou K, Arita R, Nakatsuji S, and Otani Y
- Abstract
Antiferromagnets (AFMs) have the natural advantages of terahertz spin dynamics and negligible stray fields, thus appealing for use in domain-wall applications. However, their insensitive magneto-electric responses make controlling them in domain-wall devices challenging. Recent research on noncollinear chiral AFMs Mn
3 X (X = Sn, Ge) enabled us to detect and manipulate their magnetic octupole domain states. Here, we demonstrate a current-driven fast magnetic octupole domain-wall (MODW) motion in Mn3 X. The magneto-optical Kerr observation reveals the Néel-like MODW of Mn3 Ge can be accelerated up to 750 m s-1 with a current density of only 7.56 × 1010 A m-2 without external magnetic fields. The MODWs show extremely high mobility with a small critical current density. We theoretically extend the spin-torque phenomenology for domain-wall dynamics from collinear to noncollinear magnetic systems. Our study opens a new route for antiferromagnetic domain-wall-based applications., (© 2024. The Author(s).)- Published
- 2024
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37. Effects of a Long-Acting Diquafosol Ophthalmic Solution on the Ocular Surface, Tolerability, and Usability in Dry Eye Disease.
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Kaido M and Arita R
- Subjects
- Humans, Male, Female, Middle Aged, Retrospective Studies, Aged, Tears drug effects, Adult, Delayed-Action Preparations, Treatment Outcome, Surveys and Questionnaires, Dry Eye Syndromes drug therapy, Uracil Nucleotides therapeutic use, Uracil Nucleotides administration & dosage, Ophthalmic Solutions therapeutic use, Polyphosphates therapeutic use, Polyphosphates administration & dosage
- Abstract
Introduction: This study aimed to investigate the tolerability of high-viscosity diquafosol tetrasodium (DQS) ophthalmic solution (DIQUAS LX; DQSLX) and examine its usability and effect on clinical findings in patients with dry eye disease (DED)., Methods: This interventional retrospective study included 66 eyes of 66 patients with DED who switched from conventional DQS to DQSLX ophthalmic solution. Tear function assessments (tear film breakup time [BUT], keratoconjunctival vital staining [VS] score), evaluations of DED symptom relief, and a four-item usability questionnaire ("comfort upon instillation," "irritation upon instillation," "eye mucus discharge," "convenience of instillation frequency") assessed using a visual analog scale from 0 (worst) to 10 (best) were administered 4 weeks after switching to DQSLX. Factors associated with drug tolerability were assessed using multiple regression analysis., Results: The symptoms improved by 64.2% after switching to DQSLX. The BUT value, VS score, and the questionnaire items "comfort upon instillation" and "convenience of instillation frequency" were significantly improved after switching to DQSLX. DQSLX tolerability was reported as acceptable in 56 (84.8%) and unacceptable in 10 (15.2%) patients. Overall, DQSLX tolerability was significantly associated with "comfort upon instillation" and "convenience of instillation frequency" and tended to be associated with a VS score ≥ 1. DQSLX tolerability depended on symptom and VS score improvements and absence of excessive "eye mucus discharge" in patients with a VS score ≥ 1 (39 patients), but on "comfort upon instillation" and absence of excessive "eye mucus discharge" in patients with a VS score = 0 (27 patients)., Conclusion: The high-viscosity DQSLX ophthalmic solution was generally considered acceptable in the study population. However, drug tolerability seemingly differed between patients with DED with and without epithelial damage. The former were affected by improvements in symptoms and clinical findings, whereas the latter were affected by comfort upon instillation., Trial Registration: University Hospital Medical Information Network identifier, UMIN000051390., (© 2024. The Author(s), under exclusive licence to Springer Healthcare Ltd., part of Springer Nature.)
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- 2024
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38. Risk of Major Congenital Malformations Associated with the Use of Japanese Traditional (Kampo) Medicine Containing Ephedra During the First Trimester of Pregnancy.
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Noda A, Obara T, Matsuzaki F, Suzuki S, Arita R, Ohsawa M, Obara R, Morishita K, Ueno F, Shinoda G, Orui M, Murakami K, Ishikuro M, Kikuchi A, Takayama S, Ishii T, Kawame H, Kure S, and Kuriyama S
- Abstract
Background: Japanese traditional (Kampo) medicines containing ephedra may be used to treat colds during pregnancy. There are reports that ephedrine, a component of ephedra, has a risk of teratogenicity; however, the evidence remains equivocal., Objective: This study aimed to evaluate the risk of major congenital malformations (MCMs) associated with exposure to Kampo medicines containing ephedra during the first trimester of pregnancy using the Tohoku Medical Megabank Project Birth and Three-Generation Cohort Study (TMM BirThree Cohort Study)., Methods: To 23,730 mother-infant pairs who participated in the TMM BirThree Cohort Study from July 2013 to March 2017, questionnaires in early and middle pregnancy were distributed approximately at weeks 12 and 26 of pregnancy, respectively. Infants' risk of MCMs in women who used Kampo medicines containing ephedra or acetaminophen during the first trimester was assessed, and the odds ratios (ORs) were estimated with unadjusted and adjusted analyses., Results: Among 20,879 women, acetaminophen and Kampo medicines containing ephedra were used in 665 (3.19%) and 376 (1.80%) women, respectively, in the first trimester. Among the infants born to the mothers who used acetaminophen or Kampo medicine containing ephedra during the first trimester, 11 (1.65%) and 8 (2.13%), respectively, had overall MCMs. OR of overall MCMs was higher in women who used Kampo medicines containing ephedra than in those who used acetaminophen in the first trimester (adjusted OR, 1.45; 95% confidence interval (CIs), 0.57-3.71); however, the difference was not statistically significant., Conclusions: In this study, there was no statistically significant association between the use of Kampo medicines containing ephedra during the first trimester of pregnancy and the risk of MCMs. Although some point estimates of ORs exceeded 1.00, the absolute magnitude of any increased risks would be low., (© 2024. The Author(s).)
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- 2024
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39. Growth Differentiation Factor-15 Is Considered a Predictive Biomarker of Long COVID in Non-hospitalized Patients.
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Ono R, Takayama S, Abe M, Arita R, Abe T, and Ishii T
- Abstract
Mitochondrial dysfunction is associated with various diseases. Mitochondria plays a regulatory role during infection. The association between mitokines and subsequent COVID progression has not been previously studied. The retrospective cohort study aimed to investigate the potential of serum mitokines as long COVID biomarkers in non-hospitalized patients. Patients with confirmed SARS-CoV-2 infection and blood test reports between January 2021 and April 2023 were included. Patients were categorized into two groups, the recovered and long COVID groups, based on fatigue, decline in focus, and pain. Serum levels of growth differentiation factor 15 (GDF-15) and fibroblast growth factor-21 (FGF-21), which are affected by mitochondrial function, along with inflammatory and vascular endothelium markers, were measured using enzyme-linked immunosorbent assays (ELISA). A receiver operating characteristic curve was used to screen the biomarkers. The threshold value of GDF-15 in the acute phase was 965 pg/mL (sensitivity: 71.4%, specificity: 83.3%), indicating that GDF-15 may be associated with the presence of symptoms three months post onset. No association with inflammatory markers and vascular structures was observed. Therefore, elevated GDF-15 levels in the acute phase may act as a predictive biomarker of long COVID., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2024, Ono et al.)
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- 2024
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40. Band-driven switching of magnetism in a van der Waals magnetic semimetal.
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Matsuoka H, Kajihara S, Nomoto T, Wang Y, Hirayama M, Arita R, Iwasa Y, and Nakano M
- Abstract
Magnetic semimetals form an attractive class of materials because of the nontrivial contributions of itinerant electrons to magnetism. Because of their relatively low-carrier-density nature, a doping level of those materials could be largely tuned by a gating technique. Here, we demonstrate gate-tunable ferromagnetism in an emergent van der Waals magnetic semimetal Cr
3 Te4 based on an ion-gating technique. Upon doping electrons into the system, the Curie temperature ( TC ) sharply increases, approaching near to room temperature, and then decreases to some extent. This non-monotonous variation of TC accompanies the switching of the magnetic anisotropy, synchronously followed by the sign changes of the ordinary and anomalous Hall effects. Those results clearly elucidate that the magnetism in Cr3 Te4 should be governed by its semimetallic band nature.- Published
- 2024
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41. Topological band inversion and chiral Majorana mode in hcp thallium.
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Hirayama M, Nomoto T, and Arita R
- Abstract
The chiral Majorana fermion is an exotic particle that is its own antiparticle. It can arise in a one-dimensional edge of topological materials, and especially that in a topological superconductor can be exploited in non-Abelian quantum computation. While the chiral Majorana mode (CMM) remains elusive, a promising situation is realized when superconductivity coexists with a topologically non-trivial surface state. Here, we perform fully non-empirical calculation for the CMM considering superconductivity and surface relaxation, and show that hexagonal close-packed thallium (Tl) has an ideal electronic state that harbors the CMM. Thekz=0plane of Tl is a mirror plane, realizing a full-gap band inversion corresponding to a topological crystalline insulating phase. Its surface and hinge are stable and easy to make various structures. Another notable feature is that the surface Dirac point is very close to the Fermi level, so that a small Zeeman field can induce a topological transition. Our calculation indicates that Tl will provide a new platform of the Majorana fermion., (Creative Commons Attribution license.)
- Published
- 2024
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42. Electroencephalogram-detected stress levels in the frontal lobe region of patients with dry eye.
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Kaido M, Arita R, Mitsukura Y, and Tsubota K
- Subjects
- Humans, Male, Female, Prospective Studies, Cross-Sectional Studies, Middle Aged, Surveys and Questionnaires, Adult, Aged, Stress, Psychological physiopathology, Dry Eye Syndromes physiopathology, Dry Eye Syndromes metabolism, Electroencephalography methods, Tears metabolism, Frontal Lobe physiopathology
- Abstract
Purpose: To evaluate stress levels extracted from prefrontal electroencephalogram (EEG) signals and investigate their relationship with dry eye symptoms., Methods: This prospective, cross-sectional, comparative study included 25 eyes of 25 patients with aqueous tear-deficient dry eye (low Schirmer group), 25 eyes of 25 patients with short tear breakup time dry eye (short breakup time group), and 24 eyes of 24 individuals without dry eye. An EEG test, the Japanese version of the Ocular Surface Disease Index (OSDI), and a stress questionnaire were administered. EEG-detected stress levels were assessed under three conditions: eyes closed, eyes open, and eyes open under ocular surface anesthesia., Results: Stress levels were significantly lower when the eyes were closed than when they were open in all groups (all P < 0.05). Stress levels during eyes open under ocular surface anesthesia were significantly lower than those during eyes open without anesthesia only in the low Schirmer group; no differences were found between the short breakup time and control groups. OSDI scores were associated with EEG-detected stress levels (P = 0.06) and vital staining score (P < 0.05) in the low Schirmer group; they were not associated with EEG-detected stress (P > 0.05), but with subjective stress questionnaire scores and breakup time values in the short breakup time group (P < 0.05)., Conclusions: In the low Schirmer group, peripheral nerve stimulation caused by ocular surface damage induced stress reactions in the frontal lobe, resulting in dry eye symptoms. Conversely, in the short breakup time group, the stress response in the frontal lobe was not related to symptom development., Competing Interests: Declaration of competing interest Outside the submitted work, Kazuo Tsubota reports his position as the CEO of Tsubota Laboratory, Inc., Tokyo, Japan, a company developing treatment, prevention, and medical devices for dry eye. All other authors declare no conflicts of interests., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)
- Published
- 2024
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43. Quantification of caffeine in coffee cans using electrochemical measurements, machine learning, and boron-doped diamond electrodes.
- Author
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Honda T, Takemura K, Matsumae S, Morita N, Iwasaki W, Arita R, Ueda S, Liang YW, Fukuda O, Kikunaga K, and Ohmagari S
- Subjects
- Boron chemistry, Electrodes, Machine Learning, Electrolytes, Caffeine analysis, Coffee
- Abstract
Electrochemical measurements, which exhibit high accuracy and sensitivity under low contamination, controlled electrolyte concentration, and pH conditions, have been used in determining various compounds. The electrochemical quantification capability decreases with an increase in the complexity of the measurement object. Therefore, solvent pretreatment and electrolyte addition are crucial in performing electrochemical measurements of specific compounds directly from beverages owing to the poor measurement quality caused by unspecified noise signals from foreign substances and unstable electrolyte concentrations. To prevent such signal disturbances from affecting quantitative analysis, spectral data of voltage-current values from electrochemical measurements must be used for principal component analysis (PCA). Moreover, this method enables highly accurate quantification even though numerical data alone are challenging to analyze. This study utilized boron-doped diamond (BDD) single-chip electrochemical detection to quantify caffeine content in commercial beverages without dilution. By applying PCA, we integrated electrochemical signals with known caffeine contents and subsequently utilized principal component regression to predict the caffeine content in unknown beverages. Consequently, we addressed existing research problems, such as the high quantification cost and the long measurement time required to obtain results after quantification. The average prediction accuracy was 93.8% compared to the actual content values. Electrochemical measurements are helpful in medical care and indirectly support our lives., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Honda et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)
- Published
- 2024
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44. Algorithm for spin symmetry operation search.
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Shinohara K, Togo A, Watanabe H, Nomoto T, Tanaka I, and Arita R
- Abstract
A spin space group provides a suitable way of fully exploiting the symmetry of a spin arrangement with a negligible spin-orbit coupling. There has been a growing interest in applying spin symmetry analysis with the spin space group in the field of magnetism. However, there is no established algorithm to search for spin symmetry operations of the spin space group. This paper presents an exhaustive algorithm for determining the spin symmetry operations of commensurate spin arrangements. The present algorithm searches for spin symmetry operations from the symmetry operations of a corresponding nonmagnetic crystal structure and determines their spin-rotation parts by solving a Procrustes problem. An implementation is distributed under a permissive free software license in spinspg Version 0.1.1, available at https://github.com/spglib/spinspg.
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- 2024
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45. A microscopic Kondo lattice model for the heavy fermion antiferromagnet CeIn 3 .
- Author
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Simeth W, Wang Z, Ghioldi EA, Fobes DM, Podlesnyak A, Sung NH, Bauer ED, Lass J, Flury S, Vonka J, Mazzone DG, Niedermayer C, Nomura Y, Arita R, Batista CD, Ronning F, and Janoschek M
- Abstract
Electrons at the border of localization generate exotic states of matter across all classes of strongly correlated electron materials and many other quantum materials with emergent functionality. Heavy electron metals are a model example, in which magnetic interactions arise from the opposing limits of localized and itinerant electrons. This remarkable duality is intimately related to the emergence of a plethora of novel quantum matter states such as unconventional superconductivity, electronic-nematic states, hidden order and most recently topological states of matter such as topological Kondo insulators and Kondo semimetals and putative chiral superconductors. The outstanding challenge is that the archetypal Kondo lattice model that captures the underlying electronic dichotomy is notoriously difficult to solve for real materials. Here we show, using the prototypical strongly-correlated antiferromagnet CeIn
3 , that a multi-orbital periodic Anderson model embedded with input from ab initio bandstructure calculations can be reduced to a simple Kondo-Heisenberg model, which captures the magnetic interactions quantitatively. We validate this tractable Hamiltonian via high-resolution neutron spectroscopy that reproduces accurately the magnetic soft modes in CeIn3 , which are believed to mediate unconventional superconductivity. Our study paves the way for a quantitative understanding of metallic quantum states such as unconventional superconductivity., (© 2023. The Author(s).)- Published
- 2023
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46. Emergent zero-field anomalous Hall effect in a reconstructed rutile antiferromagnetic metal.
- Author
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Wang M, Tanaka K, Sakai S, Wang Z, Deng K, Lyu Y, Li C, Tian D, Shen S, Ogawa N, Kanazawa N, Yu P, Arita R, and Kagawa F
- Abstract
The anomalous Hall effect (AHE) that emerges in antiferromagnetic metals shows intriguing physics and offers numerous potential applications. Magnets with a rutile crystal structure have recently received attention as a possible platform for a collinear-antiferromagnetism-induced AHE. RuO
2 is a prototypical candidate material, however the AHE is prohibited at zero field by symmetry because of the high-symmetry [001] direction of the Néel vector at the ground state. Here, we show AHE at zero field in Cr-doped rutile, Ru0.8 Cr0.2 O2 . The magnetization, transport and density functional theory calculations indicate that appropriate doping of Cr at Ru sites reconstructs the collinear antiferromagnetism in RuO2 , resulting in a rotation of the Néel vector from [001] to [110] while maintaining a collinear antiferromagnetic state. The AHE with vanishing net moment in the Ru0.8 Cr0.2 O2 exhibits an orientation dependence consistent with the [110]-oriented Hall vector. These results demonstrate that material engineering by doping is a useful approach to manipulate AHE in antiferromagnetic metals., (© 2023. The Author(s).)- Published
- 2023
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47. Transition between distinct hybrid skyrmion textures through their hexagonal-to-square crystal transformation in a polar magnet.
- Author
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Singh D, Fujishiro Y, Hayami S, Moody SH, Nomoto T, Baral PR, Ukleev V, Cubitt R, Steinke NJ, Gawryluk DJ, Pomjakushina E, Ōnuki Y, Arita R, Tokura Y, Kanazawa N, and White JS
- Abstract
Magnetic skyrmions, topological vortex-like spin textures, garner significant interest due to their unique properties and potential applications in nanotechnology. While they typically form a hexagonal crystal with distinct internal magnetisation textures known as Bloch- or Néel-type, recent theories suggest the possibility for direct transitions between skyrmion crystals of different lattice structures and internal textures. To date however, experimental evidence for these potentially useful phenomena have remained scarce. Here, we discover the polar tetragonal magnet EuNiGe
3 to host two hybrid skyrmion phases, each with distinct internal textures characterised by anisotropic combinations of Bloch- and Néel-type windings. Variation of the magnetic field drives a direct transition between the two phases, with the modification of the hybrid texture concomitant with a hexagonal-to-square skyrmion crystal transformation. We explain these observations with a theory that includes the key ingredients of momentum-resolved Ruderman-Kittel-Kasuya-Yosida and Dzyaloshinskii-Moriya interactions that compete at the observed low symmetry magnetic skyrmion crystal wavevectors. Our findings underscore the potential of polar magnets with rich interaction schemes as promising for discovering new topological magnetic phases., (© 2023. The Author(s).)- Published
- 2023
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48. Contribution of traditional Japanese Kampo medicines, kakkonto with shosaikotokakikyosekko, in treating patients with mild-to-moderate coronavirus disease 2019: Further analysis of a multicenter, randomized controlled trial.
- Author
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Takayama S, Namiki T, Arita R, Ono R, Kikuchi A, Ohsawa M, Saito N, Suzuki S, Nakae H, Kobayashi S, Yoshino T, Ishigami T, Tanaka K, Takagi A, Yamaguchi T, Ishii T, Hisanaga A, Mitani K, and Ito T
- Subjects
- Humans, East Asian People, Japan, COVID-19 therapy, Medicine, Kampo methods, Drugs, Chinese Herbal therapeutic use, COVID-19 Drug Treatment methods
- Abstract
We previously reported the finding of symptom relief in a randomized controlled trial with the combined use of kakkonto and shosaikotokakikyosekko added to conventional treatment in patients with coronavirus disease 2019 (COVID-19). For further evaluation, we performed post hoc analysis focused on symptom disappearance without recurrence, to determine a clearer effect of Kampo medicine. Patients with mild and moderate COVID-19 were randomly allocated to a control group receiving symptomatic therapy or a Kampo group receiving kakkonto (2.5 g) with shosaikotokakikyosekko (2.5 g) three times daily in addition to symptomatic therapy. The data of 161 patients (Kampo group, n = 81; control group, n = 80) were analyzed post hoc for the time to symptom disappearance. Kaplan-Meier and Cox proportional hazard estimates of disappearance of symptoms showed that all and each symptom targeted in this study disappeared faster in the Kampo group than in the control group, although not statistically significant (all symptomatic cases; hazard ratio [HR] 3.73, 95% confidence interval [CI] 0.46-29.98, log-rank p = 0.1763). In a supplemental assessment using covariate adjustment and competing risk analysis, fever disappeared faster in the Kampo group than in the control group (all symptomatic cases, HR 1.62, 95% CI 0.99-2.64, p = 0.0557; unvaccinated cases, HR 1.68, 95% CI 1.00-2.83, p = 0.0498) and shortness of breath disappeared significantly faster in Kampo group than in control group (all symptomatic cases, HR 1.92, 95% CI 1.07-3.42, p = 0.0278; unvaccinated cases, HR 2.15, 95% CI 1.17-3.96, p = 0.0141). These results demonstrate the advantages of Kampo treatment for acute COVID-19., Competing Interests: Declaration of competing interest ST, RA, AK, MO, and TI belong to the Department of Kampo and Integrative Medicine, Tohoku University Graduate School of Medicine, which is a joint research course with TSUMURA and Co. TSUMURA and Co. is a pharmaceutical company that produces Kampo medicine in Japan. ST and MO received lecture fees from TSUMURA and Co. TY was employed in the joint research program at Keio University. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as potential conflicts of interest., (Copyright © 2023 Japanese Society of Chemotherapy, Japanese Association for Infectious Diseases, and Japanese Society for Infection Prevention and Control. Published by Elsevier Ltd. All rights reserved.)
- Published
- 2023
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49. Bulk Photovoltaic Effect Along the Nonpolar Axis in Organic-Inorganic Hybrid Perovskites.
- Author
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Noma T, Chen HY, Dhara B, Sotome M, Nomoto T, Arita R, Nakamura M, and Miyajima D
- Abstract
The origin of the bulk photovoltaic effect (BPVE) was considered as a built-in electric field formed by the macroscopic polarization of materials. Alternatively, the "shift current mechanism" has been gradually accepted as the more appropriate description of the BPVE. This mechanism implies that the photocurrent generated by the BPVE is a topological current featuring an ultrafast response and dissipation-less nature, which is very attractive for photodetector applications. Meanwhile, the origin of the BPVE in organic-inorganic hybrid perovskites (OIHPs) has not been discussed and is still widely accepted as the classical mechanism without any experimental evidence. Herein, we observed the BPVE along the nonpolar axis in OIHPs, which is inconsistent with the classical explanation. Furthermore, based on the nonlinear optical tensor correlation, we substantiated that the BPVE in OIHPs is originated in the shift current mechanism., (© 2023 Wiley-VCH GmbH.)
- Published
- 2023
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50. Health assessment of rice cultivated and harvested from plasma-irradiated seeds.
- Author
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Okumura T, Tanaka H, Nakao T, Anan T, Arita R, Shiraki M, Shiraki K, Miyabe T, Yamashita D, Matsuo K, Attri P, Kamataki K, Yamashita N, Itagaki N, Shiratani M, Hosoda S, Tanaka A, Ishibashi Y, and Koga K
- Subjects
- Mice, Animals, Seeds, Plasma, Oryza
- Abstract
This study provides the health effects assessment of rice cultivated from plasma-irradiated seeds. The rice (Oryza sativa L.) cultivated from seeds with plasma irradiation showed a growth improvement (slope-ratios of with plasma to without plasma were 1.066, 1.042, and 1.255 for tiller, and earing, and ripening periods, respectively) and an 4% increase in yield. The cultivated rice was used for repeated oral administrations to mice for 4-week period. Distilled water and rice cultivated from seeds without plasma irradiation were also used as control. The weights of the lung, kidney, liver, and spleen, with corresponding average values of 0.22 g, 0.72 g, 2.1 g, and 0.17 g for w/ plasma group and 0.22 g, 0.68 g, 2.16 g, and 0.14 g for w/o plasma group, respectively, showing no effect due to the administration of rice cultivated from plasma-irradiated seeds. Nutritional status, liver function, kidney function, and lipid, neutral fat profiles, and glucose metabolism have no significant difference between with and without plasma groups. These results show no obvious subacute effects were observed on rice grains cultivated and harvested from the mother plant that experienced growth improvement by plasma irradiation. This study provides a new finding that there is no apparent adverse health effect on the grains harvested from the plasma-irradiated seeds., (© 2023. Springer Nature Limited.)
- Published
- 2023
- Full Text
- View/download PDF
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