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Matsuo M, Ohnuma Y, Kato T, Maekawa S. Spin Current Noise of the Spin Seebeck Effect and Spin Pumping. PHYSICAL REVIEW LETTERS 2018; 120:037201. [PMID: 29400496 DOI: 10.1103/physrevlett.120.037201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Indexed: 06/07/2023]
Abstract
We theoretically investigate the fluctuation of a pure spin current induced by the spin Seebeck effect and spin pumping in a normal-metal-(NM-)ferromagnet(FM) bilayer system. Starting with a simple ferromagnet-insulator-(FI-)NM interface model with both spin-conserving and non-spin-conserving processes, we derive general expressions of the spin current and the spin-current noise at the interface within second-order perturbation of the FI-NM coupling strength, and estimate them for a yttrium-iron-garnet-platinum interface. We show that the spin-current noise can be used to determine the effective spin carried by a magnon modified by the non-spin-conserving process at the interface. In addition, we show that it provides information on the effective spin of a magnon, heating at the interface under spin pumping, and spin Hall angle of the NM.
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Nakamura O, Moritoh S, Sato K, Maekawa S, Murayama N, Himori N, Omodaka K, Sogon T, Nakazawa T. Bilberry extract administration prevents retinal ganglion cell death in mice via the regulation of chaperone molecules under conditions of endoplasmic reticulum stress. Clin Ophthalmol 2017; 11:1825-1834. [PMID: 29066860 PMCID: PMC5644593 DOI: 10.2147/opth.s145159] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Purpose To investigate the effect of bilberry extract anthocyanins on retinal ganglion cell (RGC) survival after optic nerve crush. Additionally, to determine details of the mechanism of the neuroprotective effect of bilberry extract anthocyanins and the involvement of endoplasmic reticulum stress suppression in the mouse retina. Materials and methods Anthocyanins in bilberry extract (100 mg/kg/day or 500 mg/kg/day) were administrated orally to C57BL/6J mice. The expression levels of various molecular chaperones were assessed with quantitative reverse-transcription polymerase chain reaction, Western blotting, and immunohistochemistry. RGC survival was evaluated by measuring the gene expression of RGC markers and counting retrogradely labeled RGCs after optic nerve crush. Results The protein levels of Grp78 and Grp94 increased significantly in mice after bilberry extract administration. Increased Grp78 and Grp94 levels were detected in the inner nuclear layer and ganglion cell layer of the retina, surrounding the RGCs. Gene expression of Chop, Bax, and Atf4 increased in mice after optic nerve crush and decreased significantly after oral bilberry extract administration. RGC survival after nerve crush also increased with bilberry extract administration. Conclusion These results indicate that oral bilberry extract administration suppresses RGC death. Bilberry extract administration increased Grp78 and Grp94 protein levels, an effect which may underlie the neuroprotective effect of bilberry extract after optic nerve crush. Thus, bilberry extract has a potential role in neuroprotective treatments for retinal injuries, such as those which occur in glaucoma.
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Kobayashi D, Yoshikawa T, Matsuo M, Iguchi R, Maekawa S, Saitoh E, Nozaki Y. Spin Current Generation Using a Surface Acoustic Wave Generated via Spin-Rotation Coupling. PHYSICAL REVIEW LETTERS 2017; 119:077202. [PMID: 28949686 DOI: 10.1103/physrevlett.119.077202] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2017] [Indexed: 06/07/2023]
Abstract
We demonstrate the generation of alternating spin current (SC) via spin-rotation coupling (SRC) using a surface acoustic wave (SAW) in a Cu film. Ferromagnetic resonance caused by injecting SAWs was observed in a Ni-Fe film attached to a Cu film, with the resonance further found to be suppressed through the insertion of a SiO_{2} film into the interface. The intensity of the resonance depended on the angle between the wave vector of the SAW and the magnetization of the Ni-Fe film. This angular dependence is explicable in terms of the presence of spin transfer torque from a SC generated via SRC.
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Maekawa S, Sato K, Fujita K, Daigaku R, Tawarayama H, Murayama N, Moritoh S, Yabana T, Shiga Y, Omodaka K, Maruyama K, Nishiguchi KM, Nakazawa T. The neuroprotective effect of hesperidin in NMDA-induced retinal injury acts by suppressing oxidative stress and excessive calpain activation. Sci Rep 2017; 7:6885. [PMID: 28761134 PMCID: PMC5537259 DOI: 10.1038/s41598-017-06969-4] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Accepted: 06/22/2017] [Indexed: 12/21/2022] Open
Abstract
We found that hesperidin, a plant-derived bioflavonoid, may be a candidate agent for neuroprotective treatment in the retina, after screening 41 materials for anti-oxidative properties in a primary retinal cell culture under oxidative stress. We found that the intravitreal injection of hesperidin in mice prevented reductions in markers of the retinal ganglion cells (RGCs) and RGC death after N-methyl-D-aspartate (NMDA)-induced excitotoxicity. Hesperidin treatment also reduced calpain activation, reactive oxygen species generation and TNF-α gene expression. Finally, hesperidin treatment improved electrophysiological function, measured with visual evoked potential, and visual function, measured with optomotry. Thus, we found that hesperidin suppressed a number of cytotoxic factors associated with NMDA-induced cell death signaling, such as oxidative stress, over-activation of calpain, and inflammation, thereby protecting the RGCs in mice. Therefore, hesperidin may have potential as a therapeutic supplement for protecting the retina against the damage associated with excitotoxic injury, such as occurs in glaucoma and diabetic retinopathy.
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Kikuchi A, Shiga Y, Takayama S, Arita R, Maekawa S, Kaneko S, Himori N, Ishii T, Nakazawa T. Traditional medicine as a potential treatment for Flammer syndrome. EPMA J 2017; 8:171-175. [PMID: 28725293 PMCID: PMC5486530 DOI: 10.1007/s13167-017-0091-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Accepted: 03/30/2017] [Indexed: 11/30/2022]
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Kiyota N, Shiga Y, Suzuki S, Sato M, Takada N, Maekawa S, Omodaka K, Maruyama K, Kunikata H, Nakazawa T. The Effect of Systemic Hyperoxia on Optic Nerve Head Blood Flow in Primary Open-Angle Glaucoma Patients. Invest Ophthalmol Vis Sci 2017; 58:3181-3188. [PMID: 28654983 DOI: 10.1167/iovs.17-21648] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose To assess the optic nerve head blood flow (ONH BF) response to hyperoxia in glaucoma patients using laser speckle flowgraphy (LSFG), and determine factors influencing vasoreactivity within the ONH. Methods We performed oxygen provocation testing in 15 eyes of 15 primary open-angle glaucoma (POAG) patients and 15 eyes of 15 age-matched control subjects. During the test, LSFG-derived tissue mean blur rate (MBRT) and clinical variables, including blood pressure, were recorded. We evaluated differences in MBRT alteration during systemic hyperoxia between the groups. Additionally, we calculated the mean % change in MBRT against baseline and determined contributing factors. Results Despite similar clinical variables during systemic hyperoxia in both groups, the mean % change in MBRT against baseline was significantly lower in the POAG than control subjects (P < 0.0001). Multiple regression analysis revealed that baseline MBRT and systolic blood pressure (SBP) were contributing factors to mean % change in MBRT (β = 0.44, β = -0.32, respectively). Additionally, baseline MBRT and SBP were strongly correlated to mean % change in MBRT only in the POAG group (r = 0.83, P < 0.0001; r = -0.60, P = 0.02, respectively). Conclusions POAG patients had a weaker vasoreactive response to hyperoxia than controls, and this impaired response was associated with lower basal ONH BF and higher SBP. These findings suggest that pre-existing vasoconstriction in the ONH of eyes with glaucoma might reduce the capacity of the vasoconstrictive response to hyperoxia. Alternatively, the pathways that mediate hyperoxia-induced vasoconstriction could be altered in POAG.
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Ikeda M, Kobayashi T, Suzuki T, Wakabayashi Y, Ohama Y, Maekawa S, Takahashi S, Homma Y, Tatsuno K, Sato T, Okugawa S, Moriya K, Yotsuyanagi H. Propionimicrobium lymphophilum and Actinotignum schaalii bacteraemia: a case report. New Microbes New Infect 2017; 18:18-21. [PMID: 28491325 PMCID: PMC5412094 DOI: 10.1016/j.nmni.2017.03.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2016] [Revised: 03/25/2017] [Accepted: 03/28/2017] [Indexed: 11/26/2022] Open
Abstract
Propionimicrobium lymphophilum is an anaerobic Gram-positive bacillus that exists in human skin and urinary tract. The pathogenicity is, however, not well known. Only two cases of urinary tract infection have been described recently. In the case presented here, the bacterium was isolated, concomitant with Actinotignum schaalii, from blood culture of a patient with fever and difficulty of urination. The bacteria were identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and 16S rRNA sequencing. The case was successfully treated with ampicillin/sulbactam.
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Aono N, Obata R, Maekawa S, Oka N, Takeuchi T, Igarashi H, Kyono K. The morphokinetic characteristics of embryos derived from pcos patients. Fertil Steril 2016. [DOI: 10.1016/j.fertnstert.2016.07.107] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Maekawa S, Katagiri S, Takeuchi Y, Komazaki R, Ohtsu A, Udagawa S, Izumi Y. Bone metabolic microarray analysis of ligature-induced periodontitis in streptozotocin-induced diabetic mice. J Periodontal Res 2016; 52:233-245. [PMID: 27108916 DOI: 10.1111/jre.12387] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/13/2016] [Indexed: 12/27/2022]
Abstract
BACKGROUND AND OBJECTIVE Periodontal disease is a chronic infectious disease that results in bone loss. Many epidemiological studies have reported the progression of periodontal tissue destruction in patients with diabetes; however, the associated mechanism remains unclear. In this study, we comprehensively investigated how diabetes affects the periodontal tissue and alveolar bone loss using a ligature-induced periodontitis model in streptozotocin-induced diabetic (STZ) mice. MATERIAL AND METHODS Diabetes was induced by intraperitoneal injection with streptozotocin in 6-wk-old C57/BL6J male mice. A silk ligature was tied around the maxillary left second molar in 9-wk-old wild-type (WT) and STZ mice. Bone loss was evaluated at 3 and 7 d after ligation. mRNA expression levels in the gingiva between the two groups were examined by DNA microarray and quantitative polymerase chain reaction at 1, 3 and 7 d post-ligation. Tartrate-resistant acid phosphatase and alkaline phosphatase staining of the periodontal tissue was performed for evaluation of osteoclasts and osteoblasts in histological analysis. RESULTS In the gingiva, hyperglycemia upregulated the osteoprotegerin (Opg) mRNA expression and downregulated Osteocalcin mRNA expression. In the ligated gingiva, tumor necrosis factor-α (Tnf-α) mRNA expression was upregulated at 1 d post-ligation in STZ mice but not in WT mice. At 3 d post-ligation, alveolar bone loss was observed in STZ mice, but not in WT mice. Significantly severe alveolar bone loss was observed in STZ mice compared to WT mice at 7 d post-ligation. Bone metabolic analysis using DNA microarray showed significant downregulation in the mRNA expression of glioma-associated oncogene homologue 1 (Gli1) and collagen type VI alpha 1 (Col6a1) at the gingiva of the ligated site in STZ mice compared to that in WT mice. Quantitative polymerase chain reaction showed that Gli1 and Col6a1 mRNA expression levels were significantly downregulated in the gingiva of the ligated site in STZ mice compared to WT mice. Histological analysis showed lower alkaline phosphatase activity in STZ mice. In addition, an increased number of tartrate-resistant acid phosphatase-positive multinucleated cells were observed at the ligated sites in STZ mice. CONCLUSIONS These results suggest that an imbalance of bone metabolism causes osteoclastosis in insulin-deficient diabetes, and that alveolar bone loss could occur at an early phase under this condition.
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Omodaka K, Takahashi S, Matsumoto A, Maekawa S, Kikawa T, Himori N, Takahashi H, Maruyama K, Kunikata H, Akiba M, Nakazawa T. Clinical Factors Associated with Lamina Cribrosa Thickness in Patients with Glaucoma, as Measured with Swept Source Optical Coherence Tomography. PLoS One 2016; 11:e0153707. [PMID: 27100404 PMCID: PMC4839731 DOI: 10.1371/journal.pone.0153707] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2016] [Accepted: 04/03/2016] [Indexed: 11/19/2022] Open
Abstract
Purpose To investigate the influence of various risk factors on thinning of the lamina cribrosa (LC), as measured with swept-source optical coherence tomography (SS-OCT; Topcon). Methods This retrospective study comprised 150 eyes of 150 patients: 22 normal subjects, 28 preperimetric glaucoma (PPG) patients, and 100 open-angle glaucoma patients. Average LC thickness was determined in a 3 x 3 mm cube scan of the optic disc, over which a 4 x 4 grid of 16 points was superimposed (interpoint distance: 175 μm), centered on the circular Bruch’s membrane opening. The borders of the LC were defined as the visible limits of the LC pores. The correlation of LC thickness with Humphrey field analyzer-measured mean deviation (MD; SITA standard 24–2), circumpapillary retinal nerve fiber layer thickness (cpRNFLT), the vertical cup-to-disc (C/D) ratio, and tissue mean blur rate (MBR) was determined with Spearman's rank correlation coefficient. The relationship of LC thickness with age, axial length, intraocular pressure (IOP), MD, the vertical C/D ratio, central corneal thickness (CCT), and tissue MBR was determined with multiple regression analysis. Average LC thickness and the correlation between LC thickness and MD were compared in patients with the glaucomatous enlargement (GE) optic disc type and those with non-GE disc types, as classified with Nicolela’s method. Results We found that average LC thickness in the 16 grid points was significantly associated with overall LC thickness (r = 0.77, P < 0.001). The measurement time for this area was 12.4 ± 2.4 minutes. Average LC thickness in this area had a correlation coefficient of 0.57 with cpRNFLT (P < 0.001) and 0.46 (P < 0.001) with MD. Average LC thickness differed significantly between the groups (normal: 268 ± 23 μm, PPG: 248 ± 13 μm, OAG: 233 ± 20 μm). Multiple regression analysis showed that MD (β = 0.29, P = 0.013), vertical C/D ratio (β = -0.25, P = 0.020) and tissue MBR (β = 0.20, P = 0.034) were independent variables significantly affecting LC thickness, but age, axial length, IOP, and CCT were not. LC thickness was significantly lower in the GE patients (233.9 ± 17.3 μm) than the non-GE patients (243.6 ± 19.5 μm, P = 0.040). The correlation coefficient between MD and LC thickness was 0.58 (P < 0.001) in the GE patients and 0.39 (P = 0.013) in the non-GE patients. Conclusion Cupping formation and tissue blood flow were independently correlated to LC thinning. Glaucoma patients with the GE disc type, who predominantly have large cupping, had lower LC thickness even with similar glaucoma severity.
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Niimi Y, Kimata M, Omori Y, Gu B, Ziman T, Maekawa S, Fert A, Otani Y. Strong Suppression of the Spin Hall Effect in the Spin Glass State. PHYSICAL REVIEW LETTERS 2015; 115:196602. [PMID: 26588404 DOI: 10.1103/physrevlett.115.196602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Indexed: 06/05/2023]
Abstract
We have measured spin Hall effects in spin glass metals, CuMnBi alloys, with the spin absorption method in the lateral spin valve structure. Far above the spin glass temperature T(g) where the magnetic moments of Mn impurities are randomly frozen, the spin Hall angle of a CuMnBi ternary alloy is as large as that of a CuBi binary alloy. Surprisingly, however, it starts to decrease at about 4T(g) and becomes as little as 7 times smaller at 0.5T(g). A similar tendency was also observed in anomalous Hall effects in the ternary alloys. We propose an explanation in terms of a simple model considering the relative dynamics between the localized moment and the conduction electron spin.
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Miyakoshi N, Aizawa T, Sasaki S, Ando S, Maekawa S, Aonuma H, Tsuchie H, Sasaki H, Kasukawa Y, Shimada Y. Healing of bisphosphonate-associated atypical femoral fractures in patients with osteoporosis: a comparison between treatment with and without teriparatide. J Bone Miner Metab 2015; 33:553-9. [PMID: 25227287 DOI: 10.1007/s00774-014-0617-3] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Accepted: 07/07/2014] [Indexed: 11/30/2022]
Abstract
Atypical femoral fracture (AFF) often appears with bisphosphonate use. Teriparatide (TPTD) treatment may promote AFF healing, but few controlled or comparative studies have examined the effects of TPTD on healing of bisphosphonate-associated AFF. We retrospectively reviewed the medical records of 45 consecutive AFFs in 34 Japanese patients who had received oral bisphosphonates (alendronate or risedronate) for osteoporosis before AFF and had been followed for ≥12 months (range, 12-90 months). Thirty-seven complete or incomplete AFFs (82 %) were treated surgically and eight incomplete AFFs (18 %) were treated conservatively. Bisphosphonates were stopped at diagnosis. Based on TPTD use after fracture, AFFs were divided into non-TPTD (n = 24) and TPTD (n = 21) groups. Time to fracture-healing and frequency of delayed healing or non-union were compared between groups. Because fracture type (complete or incomplete) differed significantly between groups, only subanalyses for all surgically treated AFFs (complete and incomplete), surgically treated complete AFFs, and conservatively treated incomplete AFFs were performed. In subanalyses for all AFFs treated surgically, mean (± standard deviation) time to fracture healing was significantly better in the TPTD group (5.4 ± 1.5 months) than in the non-TPTD group (8.6 ± 4.7 months; P = 0.012), and the frequency of delayed healing or non-union was significantly lower in the TPTD group than in the non-TPTD group (P = 0.014). Subanalyses for surgically treated complete AFFs yielded similar results, but subanalyses for incomplete AFFs treated conservatively showed no significant differences between groups. TPTD treatment appears to significantly shorten the postoperative time to fracture healing and reduce rates of delayed healing or non-union after bisphosphonate-associated AFF.
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Wakamura T, Akaike H, Omori Y, Niimi Y, Takahashi S, Fujimaki A, Maekawa S, Otani Y. Quasiparticle-mediated spin Hall effect in a superconductor. NATURE MATERIALS 2015; 14:675-678. [PMID: 25985459 DOI: 10.1038/nmat4276] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Accepted: 03/26/2015] [Indexed: 06/04/2023]
Abstract
In some materials the competition between superconductivity and magnetism brings about a variety of unique phenomena such as the coexistence of superconductivity and magnetism in heavy-fermion superconductors or spin-triplet supercurrent in ferromagnetic Josephson junctions. Recent observations of spin-charge separation in a lateral spin valve with a superconductor evidence that these remarkable properties are applicable to spintronics, although there are still few works exploring this possibility. Here, we report the experimental observation of the quasiparticle-mediated spin Hall effect in a superconductor, NbN. This compound exhibits the inverse spin Hall (ISH) effect even below the superconducting transition temperature. Surprisingly, the ISH signal increases by more than 2,000 times compared with that in the normal state with a decrease of the injected spin current. The effect disappears when the distance between the voltage probes becomes larger than the charge imbalance length, corroborating that the huge ISH signals measured are mediated by quasiparticles.
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Satake H, Tsuji A, Emi Y, Shimokawa M, Miyamoto Y, Saeki H, Oki E, Maekawa S, Tanioka H, Akagi Y, Baba H, Ogata Y, Maehara Y. P-244 Prospective study of S-1 + Irinotecan plus bevacizumab as second-line therapy in Japanese patients with metastatic colorectal cancer (KSCC1102). Ann Oncol 2015. [DOI: 10.1093/annonc/mdv233.241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Uchida K, Adachi H, Kikuchi D, Ito S, Qiu Z, Maekawa S, Saitoh E. Generation of spin currents by surface plasmon resonance. Nat Commun 2015; 6:5910. [PMID: 25569821 PMCID: PMC4354158 DOI: 10.1038/ncomms6910] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Accepted: 11/20/2014] [Indexed: 11/17/2022] Open
Abstract
Surface plasmons, free-electron collective oscillations in metallic nanostructures, provide abundant routes to manipulate light–electron interactions that can localize light energy and alter electromagnetic field distributions at subwavelength scales. The research field of plasmonics thus integrates nano-photonics with electronics. In contrast, electronics is also entering a new era of spintronics, where spin currents play a central role in driving devices. However, plasmonics and spin-current physics have so far been developed independently. Here we report the generation of spin currents by surface plasmon resonance. Using Au nanoparticles embedded in Pt/BiY2Fe5O12 bilayer films, we show that, when the Au nanoparticles fulfill the surface-plasmon-resonance conditions, spin currents are generated across the Pt/BiY2Fe5O12 interface. This spin-current generation cannot be explained by conventional heating effects, requiring us to introduce nonequilibrium magnons excited by surface-plasmon-induced evanescent electromagnetic fields in BiY2Fe5O12. This plasmonic spin pumping integrates surface plasmons with spin-current physics, opening the door to plasmonic spintronics. Optical methods allow for the excitation of diverse magnetic phenomena in nanostructured materials. Here, Uchida et al. demonstrate how pure spin current may be generated across a Pt/BiY2Fe5O12 thin film interface by optically exciting surface plasmon resonance in embedded gold nanoparticles.
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Maekawa S, Shiga Y, Kawasaki R, Nakazawa T. Usefulness of novel laser speckle flowgraphy-derived variables of the large vessel area in the optic nerve head in normal tension glaucoma. Clin Exp Ophthalmol 2014; 42:887-9. [DOI: 10.1111/ceo.12354] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2014] [Accepted: 04/14/2014] [Indexed: 11/30/2022]
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Annadi A, Zhang Q, Renshaw Wang X, Tuzla N, Gopinadhan K, Lü WM, Roy Barman A, Liu ZQ, Srivastava A, Saha S, Zhao YL, Zeng SW, Dhar S, Olsson E, Gu B, Yunoki S, Maekawa S, Hilgenkamp H, Venkatesan T, Ariando. Anisotropic two-dimensional electron gas at the LaAlO₃/SrTiO₃ (110) interface. Nat Commun 2013; 4:1838. [PMID: 23673623 PMCID: PMC3674248 DOI: 10.1038/ncomms2804] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2012] [Accepted: 03/25/2013] [Indexed: 11/15/2022] Open
Abstract
The observation of a high-mobility two-dimensional electron gas between two insulating complex oxides, especially LaAlO3/SrTiO3, has enhanced the potential of oxides for electronics. The occurrence of this conductivity is believed to be driven by polarization discontinuity, leading to an electronic reconstruction. In this scenario, the crystal orientation has an important role and no conductivity would be expected, for example, for the interface between LaAlO3 and (110)-oriented SrTiO3, which should not have a polarization discontinuity. Here we report the observation of unexpected conductivity at the LaAlO3/SrTiO3 interface prepared on (110)-oriented SrTiO3, with a LaAlO3-layer thickness-dependent metal-insulator transition. Density functional theory calculation reveals that electronic reconstruction, and thus conductivity, is still possible at this (110) interface by considering the energetically favourable (110) interface structure, that is, buckled TiO2/LaO, in which the polarization discontinuity is still present. The conductivity was further found to be strongly anisotropic along the different crystallographic directions with potential for anisotropic superconductivity and magnetism, leading to possible new physics and applications. Although LaAlO3 and SrTiO3 are both insulators, when they are brought together at a (100) interface, a highly conducting two-dimensional electron gas forms between them. Annandi et al. show that this also happens at a (110) interface, counter to expectations that it should not.
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D'andrea A, Riegler L, Di Palma E, Martone F, Cocchie R, Padalino R, Calabro' R, Caso P, Russo M, Bossone E, Buera Surribas I, Mutuberria Urdaniz M, Rodriguez Palomares J, Pineda Sanchez V, Otaegui Irurueta I, Gutierrez Garcia-Moreno L, Evangelista Masip A, Garcia Dorado D, Hristova K, Katova T, Kostova V, Simova I, Okino S, Sugioka J, Ikeda A, Maekawa J, Maekawa S, Ichikawa S, Kuroiwa N, Okamoto S, Fukuzawa S, Inagaki M, Spinelli L, Morisco C, Giudice K, Castaldo D, Trimarco B. Oral Abstract session * Role of imaging to predict left ventricular remodeling after acute myocardial infarction: 12/12/2013, 16:30-18:00 * Location: Bursa. Eur Heart J Cardiovasc Imaging 2013. [DOI: 10.1093/ehjci/jet221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Shiga Y, Omodaka K, Kunikata H, Ryu M, Yokoyama Y, Tsuda S, Asano T, Maekawa S, Maruyama K, Nakazawa T. Waveform analysis of ocular blood flow and the early detection of normal tension glaucoma. Invest Ophthalmol Vis Sci 2013; 54:7699-706. [PMID: 24130177 DOI: 10.1167/iovs.13-12930] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE To investigate waveform changes in blood flow (BF) in the optic nerve head (ONH) and to evaluate their usefulness in identifying normal tension glaucoma (NTG). METHODS Sixty-one eyes of 61 patients with NTG and 21 eyes of age-matched healthy control subjects were included in this study. The NTG eyes were divided into the following three groups based on the progression of their visual field defects: mild (mean deviation [MD] greater than -6.0 decibels [dB]), moderate (MD between -6.0 and -12.0 dB), and severe (MD less than -12.0 dB). The ONH BF analysis was performed with laser speckle flowgraphy (LSFG) and included waveform variables such as skew, acceleration time index (ATI), and blowout time. RESULTS In the ONH, LSFG skew variables were significantly lower in the NTG eyes than in the control eyes (P < 0.001), and ATI was significantly higher (P < 0.01), despite similar systemic characteristics in the four groups. The differences were most marked in the mild NTG group. Multiple linear regression analysis showed that MD, average thickness of the circumpapillary retinal nerve fiber layer, and pulse rate were predictive factors for both skew and ATI. A receiver operating characteristic (ROC) curve analysis also revealed that skew (area under the ROC curve, 0.89) and ATI (area under the ROC curve, 0.80) had the greatest power to differentiate normal eyes from eyes with mild NTG. CONCLUSIONS These results suggest that LSFG measurements of waveform changes in ONH BF can differentiate healthy eyes from eyes with NTG, particularly those with mild NTG.
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An T, Vasyuchka VI, Uchida K, Chumak AV, Yamaguchi K, Harii K, Ohe J, Jungfleisch MB, Kajiwara Y, Adachi H, Hillebrands B, Maekawa S, Saitoh E. Unidirectional spin-wave heat conveyer. NATURE MATERIALS 2013; 12:549-553. [PMID: 23603850 DOI: 10.1038/nmat3628] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2012] [Accepted: 03/12/2013] [Indexed: 06/02/2023]
Abstract
When energy is introduced into a region of matter, it heats up and the local temperature increases. This energy spontaneously diffuses away from the heated region. In general, heat should flow from warmer to cooler regions and it is not possible to externally change the direction of heat conduction. Here we show a magnetically controllable heat flow caused by a spin-wave current. The direction of the flow can be switched by applying a magnetic field. When microwave energy is applied to a region of ferrimagnetic Y3Fe5O12, an end of the magnet far from this region is found to be heated in a controlled manner and a negative temperature gradient towards it is formed. This is due to unidirectional energy transfer by the excitation of spin-wave modes without time-reversal symmetry and to the conversion of spin waves into heat. When a Y3Fe5O12 film with low damping coefficients is used, spin waves are observed to emit heat at the sample end up to 10 mm away from the excitation source. The magnetically controlled remote heating we observe is directly applicable to the fabrication of a heat-flow controller.
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Shindo H, Maekawa S, Komase K, Miura M, Kadokura M, Sueki R, Komatsu N, Shindo K, Amemiya F, Nakayama Y, Inoue T, Sakamoto M, Yamashita A, Moriishi K, Enomoto N. IL-28B (IFN-λ3) and IFN-α synergistically inhibit HCV replication. J Viral Hepat 2013; 20:281-9. [PMID: 23490373 DOI: 10.1111/j.1365-2893.2012.01649.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2012] [Accepted: 06/07/2012] [Indexed: 01/09/2023]
Abstract
Genetic variation in the IL-28B (interleukin-28B; interferon lambda 3) region has been associated with sustained virological response (SVR) rates in patients with chronic hepatitis C treated with peginterferon-α and ribavirin. However, the mechanisms by which polymorphisms in the IL-28B gene region affect host antiviral responses are not well understood. Using the HCV 1b and 2a replicon system, we compared the effects of IFN-λs and IFN-α on HCV RNA replication. The anti-HCV effect of IFN-λ3 and IFN-α in combination was also assessed. Changes in gene expression induced by IFN-λ3 and IFN-α were compared using cDNA microarray analysis. IFN-λs at concentrations of 1 ng/mL or more exhibited concentration- and time-dependent HCV inhibition. In combination, IFN-λ3 and IFN-α had a synergistic anti-HCV effect; however, no synergistic enhancement was observed for interferon-stimulated response element (ISRE) activity or upregulation of interferon-stimulated genes (ISGs). With respect to the time course of ISG upregulation, the peak of IFN-λ3-induced gene expression occurred later and lasted longer than that induced by IFN-α. In addition, although the genes upregulated by IFN-α and IFN-λ3 were similar to microarray analysis, interferon-stimulated gene expression appeared early and was prolonged by combined administration of these two IFNs. In conclusion, IFN-α and IFN-λ3 in combination showed synergistic anti-HCV activity in vitro. Differences in time-dependent upregulation of these genes might contribute to the synergistic antiviral activity.
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Wei D, Niimi Y, Gu B, Ziman T, Maekawa S, Otani Y. The spin Hall effect as a probe of nonlinear spin fluctuations. Nat Commun 2012; 3:1058. [DOI: 10.1038/ncomms2063] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2012] [Accepted: 08/14/2012] [Indexed: 11/09/2022] Open
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Vidmar L, Bonča J, Tohyama T, Maekawa S. Quantum dynamics of a driven correlated system coupled to phonons. PHYSICAL REVIEW LETTERS 2011; 107:246404. [PMID: 22243016 DOI: 10.1103/physrevlett.107.246404] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2011] [Indexed: 05/31/2023]
Abstract
Nonequilibrium interplay between charge, spin, and lattice degrees of freedom on a square lattice is studied for a single charge carrier doped in the t-J-Holstein model. In the presence of a static electric field we calculate the quasistationary state. With increasing electron-phonon (e-ph) coupling the carrier mobility decreases; however, we find increased steady state current due to e-ph coupling in the regime of negative differential resistance. We explore the distribution of absorbed energy between the spin and the phonon subsystem. For model parameters as relevant for cuprates, the majority of the gained energy flows into the spin subsystem.
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Yamane Y, Sasage K, An T, Harii K, Ohe J, Ieda J, Barnes SE, Saitoh E, Maekawa S. Continuous generation of spinmotive force in a patterned ferromagnetic film. PHYSICAL REVIEW LETTERS 2011; 107:236602. [PMID: 22182112 DOI: 10.1103/physrevlett.107.236602] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2011] [Indexed: 05/31/2023]
Abstract
We study, both experimentally and theoretically, the generation of a dc spinmotive force. By exciting a ferromagnetic resonance of a comb-shaped ferromagnetic thin film, a continuous spinmotive force is generated. Experimental results are well reproduced by theoretical calculations, offering a quantitative and microscopic understanding of this spinmotive force.
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Tsuchie H, Nishi T, Tani T, Maekawa S, Shimada Y. Lumbar diskal cyst containing intervertebral disk materials. Orthopedics 2011; 34:e784-7. [PMID: 22049966 DOI: 10.3928/01477447-20110922-29] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The diskal cyst is a relatively new clinical entity and develops clinical symptoms of a unilateral single nerve root lesion. Although many cases of diskal cyst have been reported, the pathogenesis of diskal cyst remains unclear, and several theories regarding the pathogenesis have been proposed. This article presents 2 cases of diskal cyst communicating with an adjacent herniated disk. Magnetic resonance imaging findings showed diskal cysts in the epidural space of the lumbar spine. Surgical resection was performed, and apparent connections between the corresponding disk and cysts were found. Histopathologic examinations of the cyst wall demonstrated cartilaginous tissue including nucleus pulposus and annulus fibrosis. These patient's symptoms improved remarkably postoperatively, and there was no recurrence of diskal cyst.The hypothesis supported by many authors is hemorrhage from the epidural venous plexus. Diskal cysts arise first from an underlying intervertebral disk injury that causes an annulus fibrosis fissure in the posterior intervertebral disk. Hemorrhage from the epidural venous plexus with a rich blood flow then occurs in the space between the peridural membrane and vertebral body. However, in our cases, we confirmed that the diskal cyst could have developed from the resorption process of an intervertebral disk herniation. Only 5 cases of diskal cyst demonstrating the presence of cartilaginous tissue in the cyst have been reported. Our 2 cases are rare and support the hypothesis of resorption of intervertebral disk herniation.
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