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Shimizu M, Ohwada W, Kouzu H, Sato T, Osanami A, Ogawa T, Ino S, Toda Y, Kuno A, Tanno M, Yano T. Nuclear accumulation of MLKL induces necroptosis in cardiomyocytes: potential implication in Doxorubicin-induced cardiotoxicity. Eur Heart J 2022. [DOI: 10.1093/eurheartj/ehac544.2926] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Background
The treatment with doxorubicin, a powerful chemotherapeutic agent, has been shown to be associated with an increased risk of lethal heart failure. Although various types of cell death pathway such as apoptosis and ferroptosis have been shown to be involved in the development of doxorubicin-induced cardiotoxicity, DIC, the involvement of necroptosis, a novel programmed necrosis induced by translocation of activated mixed lineage kinase domain-like protein, MLKL, to plasma membrane, remains unclear.
Purpose
The aim of this study was to determine whether necroptosis is involved in the development of DIC.
Methods and results
DIC was induced in C57BL/6J mice by intraperitoneal injection of doxorubicin at a dose of 10 mg/kg 3 times for a week. Eight days after the commencement of injection, echocardiographic analyses showed that left ventricular ejection fraction assessed by echocardiography was significantly lower in the doxorubicin-treated mice than in the vehicle-treated mice (44.0±13.7 vs. 70.5±3.7%), indicating the development of DIC. Immunoblot analysis showed that MLKL protein level was higher by 1.6 fold in the doxorubicin-treated mice than in the vehicle-treated mice. Interestingly, immunohistochemical analysis showed that signals of phospho-Ser345-MLKL, an activated form of MLKL, was found in the nuclei in addition to cytosol and intercalated discs of cardiomyocytes in the doxorubicin-treated mice. To get novel insight into significance of nuclear MLKL accumulation, a leucine-rich nuclear export signal (NES) spanning amino acids 280–284 of rat MLKL was identified by site-directed mutation analyses, and H9c2 cells, cultured rat cardiomyoblasts, were transfected with expression constructs for nucleus-directed MLKL (FLAG-mtNES-MLKL) or its wild type (FLAG-WT-MLKL). Percentage of FLAG-positive cells stained with Zombie Red, a fluorescent dye that is non-permeant to live cells, was higher in FLAG-mtNES-MLKL-transfected cells than in FLAG-WT-MLKL-transfected cells (80.0±3.5% vs. 6.3±1.3%, p<0.05), whereas percentage of cells immunostained with cleaved caspase-3 to FLAG-positive cells was similar in the two groups. The effect of the MLKL mutant on necroptosis was attenuated by treatment with GppNHp, an inhibitor of Ran-mediated nuclear protein import.
Conclusion
Nuclear accumulation of MLKL induces necroptosis in cardiomyocytes, which may contribute to progression of DIC.
Funding Acknowledgement
Type of funding sources: None.
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Affiliation(s)
- M Shimizu
- Sapporo Medical University, Department of Cardiovascular, Renal and Metabolic Medicine , Sapporo , Japan
| | - W Ohwada
- Sapporo Medical University, Department of Cardiovascular, Renal and Metabolic Medicine , Sapporo , Japan
| | - H Kouzu
- Sapporo Medical University, Department of Cardiovascular, Renal and Metabolic Medicine , Sapporo , Japan
| | - T Sato
- Sapporo Medical University, Department of Cellular Physiology and Signal Transduction , Sapporo , Japan
| | - A Osanami
- Sapporo Medical University, Department of Cardiovascular, Renal and Metabolic Medicine , Sapporo , Japan
| | - T Ogawa
- Sapporo Medical University, Department of Cardiovascular, Renal and Metabolic Medicine , Sapporo , Japan
| | - S Ino
- Sapporo Medical University, Department of Cardiovascular, Renal and Metabolic Medicine , Sapporo , Japan
| | - Y Toda
- Sapporo Medical University, Department of Cardiovascular, Renal and Metabolic Medicine , Sapporo , Japan
| | - A Kuno
- Sapporo Medical University, Department of Pharmacology , Sapporo , Japan
| | - M Tanno
- Sapporo Medical University, Department of Cardiovascular, Renal and Metabolic Medicine , Sapporo , Japan
| | - T Yano
- Sapporo Medical University, Department of Cardiovascular, Renal and Metabolic Medicine , Sapporo , Japan
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Fukuoka T, Yamamoto Y, Usami E, Hayashi H, Utsunomiya J, Kimura M, Nakamura M, Yoshimura T, Toda Y. Expression of Vincristin-induced Peripheral Neuropathy Related to Different Administration Methods. Pharmazie 2022; 77:162-164. [PMID: 35655379 DOI: 10.1691/ph.2022.2329] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Vincristine (VCR) is an important drug used in R-CHOP regimens for the treatment of non-Hodgkin's lymphoma. The purpose of this study was to examine whether the administration method affects the incidence of VCR-induced peripheral neuropathy. We investigated the ratio of VCR-induced peripheral neuropathy during rapid intravenous infusion and intravenous drip infusion. A total of 71 patients who had received six or more courses of R-CHOP from January, 2015 to December, 2016 at Komaki City Hospital and Ogaki Municipal Hospital were retrospectively investigated. Peripheral neuropathy was observed in 27/39 patients (69 %) and 24/32 (75 %) in rapid intravenous infusion and intravenous drip infusion of VCR, respectively (P = 0.79). Peripheral neuropathy was observed at a high frequency in this study. Additionally, there was no difference in frequency of peripheral neuropathy due to the difference in administration method. In both groups, the degree of peripheral neuropathy was grade 1 and grade 2 in most patients. However, in rapid intravenous infusion, grade 3 peripheral neuropathy was observed. Some cases required dose reduction and discontinuation in rapid intravenous infusion. In contrast, there were no discontinuing patients in the intravenous drip infusion. Therefore, it was suggested that intravenous drip infusion of VCR reduced serious peripheral neuropathy because the ratio requiring dose reduction and discontinuation was less than that in the rapid group. In conclusion, this study is informative as there are few reports focusing on the administration method of vincristine.
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Affiliation(s)
- T Fukuoka
- Department of Pharmacy, Komaki City Hospital, 1-20 Jyobushi, Komaki-shi, Aichi 485-8520, Japan; ; Department of Pharmacy, Komaki City Hospital, Aichi;,
| | - Y Yamamoto
- Department of Pharmacy, Komaki City Hospital, Aichi
| | - E Usami
- Department of Pharmacy, Ogaki Municipal Hospital
| | - H Hayashi
- Department of Pharmacy, Komaki City Hospital, Aichi
| | - J Utsunomiya
- Department of Pharmacy, Komaki City Hospital, Aichi
| | - M Kimura
- Department of Pharmacy, Ogaki Municipal Hospital
| | - M Nakamura
- Laboratory of Drug Informatics, Gifu Pharmaceutical University, Gifu, Japan
| | - T Yoshimura
- Department of Pharmacy, Ogaki Municipal Hospital
| | - Y Toda
- Department of Pharmacy, Komaki City Hospital, Aichi
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Jiang G, Matsui N, Mezaki T, Toda Y, Suzuki K, Hirayama M, Saito T, Kamiyama T, Kanno R. Synthesis, structure, and electrical conductivity of Sr2LiH2N nitride hydride. J SOLID STATE CHEM 2022. [DOI: 10.1016/j.jssc.2022.123051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Noguchi Y, Toda Y, Esaki H, Matsuyama T, Tachi T, Tsuchiya T, Teramachi H. Association between dipeptidyl peptidase-4 inhibitors and autoimmune disorders: Data mining of the spontaneous reporting system in Japan. Pharmazie 2020; 74:305-309. [PMID: 31109402 DOI: 10.1691/ph.2019.8972] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The main objective of this study is to conduct a disproportionality analysis of adverse events in the Japan Adverse Event Report (JADER) database and evaluate the risk of the DPP-4 inhibitor induced autoimmune disorder, the secondary objective is risk assessment of sex difference and age difference. The proportional reporting ratio (PRR) of frequency-based statistics and Bayesian estimates of the information components (IC) were calculated as a measure of signal detection. Sex difference and age difference were evaluated using signal score calculated from the PRR and the Chi-square. In patients taking DPP-4 inhibitors, 94 reports of autoimmune disorders were detected with both signals; PRR: 4.09, chi-square: 158.26 and IC: 1.66, 95 % confidence interval: 1.32-2.00). For other antidiabetic drugs, no signals were detected. The signal of males was PRR: 4.53, chi-square: 110.91 and signal score: 6.22, the signal of female was PRR: 3.53, chi-square: 47.65 and signal score: 5.12. About age difference, the signal scores were 6.71 for patients over 60 years and 0.56 for patients under 60 years old. This study suggests that the DPP-4 inhibitors, unlike other antidiabetic drugs, were associated with autoimmune disorders. Signals of the DPP-4 inhibitors induced autoimmune disorders were detected in both male and female, but no sex difference was observed, but age difference was observed. Especially attention should be paid to patients over 60 years old.
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Ogai N, Nonaka I, Toda Y, Ono T, Minegishi S, Inou A, Hachiya M, Fukamizu H. Enhanced immunity in intradermal vaccination by novel hollow microneedles. Skin Res Technol 2018; 24:630-635. [PMID: 29707828 DOI: 10.1111/srt.12576] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/02/2018] [Indexed: 12/11/2022]
Abstract
BACKGROUND The intradermal (ID) route for vaccination represents an effective alternative to subcutaneous (SC)/intramuscular administration to induce protective immunity. However, a critical issue associated with ID vaccination is the precise delivery of solution in the upper dermis, which ensures enhanced immunity. METHODS We fabricated a hollow microneedle unit made of poly-glycolic acid by injection molding and bonding, and created a dedicated prototype injector. To ensure ID delivery of solution, the injected site was macroscopically and microscopically examined. Serum immunoglobulin G antibody production was measured by enzyme immunoassay and compared in groups of rats following either ID delivery with microneedles or SC administration with a 27-G stainless needle of graded vaccine doses. RESULTS The unit used a tandem array of six microneedles, each with a side delivery hole, and a conduit inside for solution. Microneedles installed in the injector punctured the skin with the aid of a spring. Injection of solution formed a wheal due to ID distribution. Histologically, a wedge-shaped skin defect in the upper skin corresponded to each puncture site. Antibody titers following vaccinations on days 1 and 8 were significantly higher with ID injection than with SC delivery on day 15 and every 7 days thereafter until day 36 with mumps vaccination, and until day 36 with varicella vaccination. CONCLUSIONS The microneedle unit presented here delivered solution intradermally without any difficulty and evoked antibody responses against viruses even with the reduced vaccine volume. Our findings confirm promising results of ID delivery as an immunogenic option to enhance vaccination efficacy.
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Affiliation(s)
- N Ogai
- ASTI Corporation, Hamamatsu, Japan
| | - I Nonaka
- ASTI Corporation, Hamamatsu, Japan
| | - Y Toda
- ASTI Corporation, Hamamatsu, Japan
| | - T Ono
- ASTI Corporation, Hamamatsu, Japan
| | | | - A Inou
- ASTI Corporation, Hamamatsu, Japan
| | | | - H Fukamizu
- Department of Plastic and Reconstructive Surgery, Hamamatsu University School of Medicine, Hamamatsu, Japan
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Tanooka M, Tarutani K, Doi H, Suzuki H, Takada Y, Fujiwara M, Toda Y, Fujimoto H, Miyashita M, Okumura A, Kagawa K, Kamikonya N, Yamakado K. EP-1753: Sensing ability of EPID-based in vivo dosimetry for VMAT. Radiother Oncol 2018. [DOI: 10.1016/s0167-8140(18)32062-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Toda Y, Ishiyama S, Khutoryan E, Idehara T, Matsuishi S, Sushko PV, Hosono H. Rattling of Oxygen Ions in a Sub-Nanometer-Sized Cage Converts Terahertz Radiation to Visible Light. ACS Nano 2017; 11:12358-12364. [PMID: 29099586 DOI: 10.1021/acsnano.7b06277] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
A simple and robust approach to visualization of continuous wave terahertz (CW-THz) light would open up opportunities to couple physical phenomena that occur at fundamentally different energy scales. Here we demonstrate how nanoscale cages of Ca12Al14O33 crystal enable conversion of CW-THz radiation to visible light. These crystallographic cages are partially occupied with weakly bonded oxygen ions and give rise to a narrow conduction band that can be populated with localized, yet mobile electrons. CW-THz light excites a nearly stand-alone rattling motion of the encaged oxygen species, which promotes electron transfer from them to the neighboring vacant cages. When the power of CW-THz light reaches tens of watts, the coupling between forced rattling in the confined space, electronic excitation and ionization of oxygen species, and corresponding recombination processes result in emission of bright visible light.
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Affiliation(s)
- Yoshitake Toda
- Materials Research Center for Element Strategy, Tokyo Institute of Technology , 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8503, Japan
| | - Shintaro Ishiyama
- Graduate School of Science and Technology, Hirosaki University , 1 Bunkyo-cho, Hirosaki-shi, Aomori-ken 036-8560, Japan
- Research Center for Development of Far-Infrared Region, University of Fukui , Bunkyo 3-9-1, Fukui 910-8507, Japan
| | - Eduard Khutoryan
- Institute of Radio Physics and Electronics, National Academy of Science of Ukraine , Volodymyrska 54, Kyiv, 01030, Ukraine
| | - Toshitaka Idehara
- Research Center for Development of Far-Infrared Region, University of Fukui , Bunkyo 3-9-1, Fukui 910-8507, Japan
| | - Satoru Matsuishi
- Materials Research Center for Element Strategy, Tokyo Institute of Technology , 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8503, Japan
| | - Peter V Sushko
- Physical Sciences Division, Physical & Computational Sciences Directorate, Pacific Northwest National Laboratory , 902 Battelle Boulevard, Richland, Washington 99352, United States
| | - Hideo Hosono
- Materials Research Center for Element Strategy, Tokyo Institute of Technology , 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8503, Japan
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Abstract
Transparent bipolar semiconductors (TBSCs) are in demand for transparent electronics to serve as the basis for next generation optoelectronic devices. However, the poor carrier controllability in wide-bandgap materials makes the realization of a bipolar nature difficult. Only two materials, CuInO2 and SnO, have been reported as TBSCs. To satisfy demand for the coexistence of transparency and bipolarity, we propose a design concept with three strategies; choice of early transition metals (eTM) such as Y3+ and Zr4+ for improving controllability of carrier doping, design of chemical bonds to obtain an appropriate band structure for bipolar doping, and use of a forbidden band-edge transition to retain transparency. This approach is verified through a practical examination of a candidate material, tetragonal ZrOS, which is chosen by following the criteria. ZrOS exhibits an excellent controllability of the electrical conductivity (10-7-10-2 S cm-1), p- or n-type nature with ∼10-2 S cm-1 by Y or F doping, respectively, and optically wide gap (below 10-4 cm-1 up to ∼2.5 eV). This concept provides a new kind of TBSC based on eTM ionic compounds.
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Affiliation(s)
- Takeshi Arai
- Laboratory for Materials and Structures, Tokyo Institute of Technology , Yokohama 226-8503, Japan
| | - Soshi Iimura
- Laboratory for Materials and Structures, Tokyo Institute of Technology , Yokohama 226-8503, Japan
| | - Junghwan Kim
- Research Center for Element Strategy, Tokyo Institute of Technology , Yokohama 226-8503, Japan
| | - Yoshitake Toda
- Research Center for Element Strategy, Tokyo Institute of Technology , Yokohama 226-8503, Japan
| | - Shigenori Ueda
- Synchrotron X-ray Station at SPring-8, National Institute for Materials Science , Sayoto 679-5148, Japan.,Research Center for Advanced Measurement and Characterization, National Institute for Materials Science , Tsukuba 305-0047, Japan
| | - Hideo Hosono
- Laboratory for Materials and Structures, Tokyo Institute of Technology , Yokohama 226-8503, Japan.,Research Center for Element Strategy, Tokyo Institute of Technology , Yokohama 226-8503, Japan
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Takashima H, Sakurai S, Kurita A, Ando H, Suzuki A, So T, Toda Y, Waseda K, Amano T. P6495Impact of hemodialysis on long-term clinical outcomes in deferral patients. Eur Heart J 2017. [DOI: 10.1093/eurheartj/ehx493.p6495] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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11
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Lu Y, Li J, Tada T, Toda Y, Ueda S, Yokoyama T, Kitano M, Hosono H. Water Durable Electride Y5Si3: Electronic Structure and Catalytic Activity for Ammonia Synthesis. J Am Chem Soc 2016; 138:3970-3. [DOI: 10.1021/jacs.6b00124] [Citation(s) in RCA: 173] [Impact Index Per Article: 21.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Yangfan Lu
- Materials Research Center for Element Strategy, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan
- ACCEL, Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan
| | - Jiang Li
- Materials Research Center for Element Strategy, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan
- ACCEL, Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan
| | - Tomofumi Tada
- Materials Research Center for Element Strategy, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan
| | - Yoshitake Toda
- Materials Research Center for Element Strategy, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan
- ACCEL, Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan
| | - Shigenori Ueda
- Synchrotron X-ray Station at SPring-8, National Institute for Material Science (NIMS), 1-1-1 Kouto, Sayo, Hyogo 679-5148, Japan
- Quantum Beam Unit, NIMS, 1-2-1 Sengen, Tsukuba 305-0047, Japan
| | - Toshiharu Yokoyama
- Materials Research Center for Element Strategy, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan
- ACCEL, Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan
| | - Masaaki Kitano
- Materials Research Center for Element Strategy, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan
| | - Hideo Hosono
- Materials Research Center for Element Strategy, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan
- ACCEL, Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan
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Kim J, Watanabe S, Matsuzaki E, Nakamura N, Miyakawa N, Toda Y, Kamiya T, Hosono H. P-177L: Late-News Poster
: Highly Efficient Inverted OLEDs using A New Transparent Amorphous Oxide Semiconductor. ACTA ACUST UNITED AC 2015. [DOI: 10.1002/sdtp.10190] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Junghwan Kim
- Tokyo Institute of Technology, Nagatsuta, Midori-ku, Yokohama 226-8503, Japan
| | - Satoru Watanabe
- Research Center, Asahi Glass Co. Ltd, Hazawa, Kanagawa-ku, Yokohama 221-8755, Japan
- ACEEL Program, Japan Science and Technology Agency, Kawaguchi 332-0012, Japan
| | - Eiji Matsuzaki
- Tokyo Institute of Technology, Nagatsuta, Midori-ku, Yokohama 226-8503, Japan
- ACEEL Program, Japan Science and Technology Agency, Kawaguchi 332-0012, Japan
| | - Nobuhiro Nakamura
- Tokyo Institute of Technology, Nagatsuta, Midori-ku, Yokohama 226-8503, Japan
- Research Center, Asahi Glass Co. Ltd, Hazawa, Kanagawa-ku, Yokohama 221-8755, Japan
| | - Naomichi Miyakawa
- Research Center, Asahi Glass Co. Ltd, Hazawa, Kanagawa-ku, Yokohama 221-8755, Japan
| | - Yoshitake Toda
- Tokyo Institute of Technology, Nagatsuta, Midori-ku, Yokohama 226-8503, Japan
- ACEEL Program, Japan Science and Technology Agency, Kawaguchi 332-0012, Japan
| | - Toshio Kamiya
- Tokyo Institute of Technology, Nagatsuta, Midori-ku, Yokohama 226-8503, Japan
| | - Hideo Hosono
- Tokyo Institute of Technology, Nagatsuta, Midori-ku, Yokohama 226-8503, Japan
- ACEEL Program, Japan Science and Technology Agency, Kawaguchi 332-0012, Japan
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Ran FY, Xiao Z, Toda Y, Hiramatsu H, Hosono H, Kamiya T. n-type conversion of SnS by isovalent ion substitution: Geometrical doping as a new doping route. Sci Rep 2015; 5:10428. [PMID: 26020855 PMCID: PMC4446993 DOI: 10.1038/srep10428] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Accepted: 04/13/2015] [Indexed: 11/21/2022] Open
Abstract
Tin monosulfide (SnS) is a naturally p-type semiconductor with a layered crystal structure, but no reliable n-type SnS has been obtained by conventional aliovalent ion substitution. In this work, carrier polarity conversion to n-type was achieved by isovalent ion substitution for polycrystalline SnS thin films on glass substrates. Substituting Pb2+ for Sn2+ converted the majority carrier from hole to electron, and the free electron density ranged from 1012 to 1015 cm−3 with the largest electron mobility of 7.0 cm2/(Vs). The n-type conduction was confirmed further by the position of the Fermi level (EF) based on photoemission spectroscopy and electrical characteristics of pn heterojunctions. Density functional theory calculations reveal that the Pb substitution invokes a geometrical size effect that enlarges the interlayer distance and subsequently reduces the formation energies of Sn and Pb interstitials, which results in the electron doping.
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Affiliation(s)
- Fan-Yong Ran
- 1] Materials and Structures Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan [2] Materials Research Center for Element Strategy, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan
| | - Zewen Xiao
- 1] Materials and Structures Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan [2] Materials Research Center for Element Strategy, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan
| | - Yoshitake Toda
- 1] Materials Research Center for Element Strategy, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan [2] Frontier Research Center, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan
| | - Hidenori Hiramatsu
- 1] Materials and Structures Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan [2] Materials Research Center for Element Strategy, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan
| | - Hideo Hosono
- 1] Materials and Structures Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan [2] Materials Research Center for Element Strategy, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan [3] Frontier Research Center, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan
| | - Toshio Kamiya
- 1] Materials and Structures Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan [2] Materials Research Center for Element Strategy, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan
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Madan I, Kurosawa T, Toda Y, Oda M, Mertelj T, Mihailovic D. Evidence for carrier localization in the pseudogap state of cuprate superconductors from coherent quench experiments. Nat Commun 2015; 6:6958. [PMID: 25891310 PMCID: PMC4411302 DOI: 10.1038/ncomms7958] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Accepted: 03/19/2015] [Indexed: 11/09/2022] Open
Abstract
A 'pseudogap' was introduced by Mott to describe a state of matter that has a minimum in the density of states at the Fermi level, deep enough for states to become localized. It can arise either from Coulomb repulsion between electrons, and/or incipient charge or spin order. Here we employ ultrafast spectroscopy to study dynamical properties of the normal to pseudogap state transition in the prototype high-temperature superconductor Bi2Sr2CaCu2O8+δ. We perform a systematic temperature and doping dependence study of the pseudogap photodestruction and recovery in coherent quench experiments, revealing marked absence of critical behaviour of the elementary excitations, which implies an absence of collective electronic ordering beyond a few coherence lengths on short timescales. The data imply ultrafast carrier localization into a textured polaronic state arising from a competing Coulomb interaction and lattice strain, enhanced by a Fermi surface instability.
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Affiliation(s)
- I Madan
- Jozef Stefan Institute and International Postgraduate School, Jamova 39, SI-1000 Ljubljana, Slovenia
| | - T Kurosawa
- Department of Physics, Hokkaido University, Sapporo 060-0810, Japan
| | - Y Toda
- Department of Applied Physics, Hokkaido University, Sapporo 060-8628, Japan
| | - M Oda
- Department of Physics, Hokkaido University, Sapporo 060-0810, Japan
| | - T Mertelj
- Jozef Stefan Institute and International Postgraduate School, Jamova 39, SI-1000 Ljubljana, Slovenia
| | - D Mihailovic
- Jozef Stefan Institute and International Postgraduate School, Jamova 39, SI-1000 Ljubljana, Slovenia
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Xiao Z, Hiramatsu H, Ueda S, Toda Y, Ran FY, Guo J, Lei H, Matsuishi S, Hosono H, Kamiya T. Narrow bandgap in β-BaZn₂As₂ and its chemical origins. J Am Chem Soc 2014; 136:14959-65. [PMID: 25255380 DOI: 10.1021/ja507890u] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
β-BaZn2As2 is known to be a p-type semiconductor with the layered crystal structure similar to that of LaZnAsO, leading to the expectation that β-BaZn2As2 and LaZnAsO have similar bandgaps; however, the bandgap of β-BaZn2As2 (previously reported value ~0.2 eV) is 1 order of magnitude smaller than that of LaZnAsO (1.5 eV). In this paper, the reliable bandgap value of β-BaZn2As2 is determined to be 0.23 eV from the intrinsic region of the temperature dependence of electrical conductivity. The origins of this narrow bandgap are discussed based on the chemical bonding nature probed by 6 keV hard X-ray photoemission spectroscopy, hybrid density functional calculations, and the ligand theory. One origin is the direct As-As hybridization between adjacent [ZnAs] layers, which leads to a secondary splitting of As 4p levels and raises the valence band maximum. The other is that the nonbonding Ba 5d(x(2)-y(2)) orbitals form an unexpectedly deep conduction band minimum (CBM) in β-BaZn2As2 although the CBM of LaZnAsO is formed mainly of Zn 4s. These two origins provide a quantitative explanation for the bandgap difference between β-BaZn2As2 and LaZnAsO.
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Affiliation(s)
- Zewen Xiao
- Materials and Structures Laboratory, ‡Materials Research Center for Element Strategy, and #Frontier Research Center, Tokyo Institute of Technology , Yokohama 226-8503, Japan
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16
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Hayashi F, Tomota Y, Kitano M, Toda Y, Yokoyama T, Hosono H. NH2– Dianion Entrapped in a Nanoporous 12CaO·7Al2O3 Crystal by Ammonothermal Treatment: Reaction Pathways, Dynamics, and Chemical Stability. J Am Chem Soc 2014; 136:11698-706. [DOI: 10.1021/ja504185m] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- Fumitaka Hayashi
- Frontier
Research Center, Tokyo Institute of Technology, 4259-S2-13 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan
| | - Yudai Tomota
- Materials
and Structures Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan
| | - Masaaki Kitano
- Materials
Research Center for Element Strategy, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan
| | - Yoshitake Toda
- Frontier
Research Center, Tokyo Institute of Technology, 4259-S2-13 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan
- Accel
Program, Japan Science and Technology Agency (JST), 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan
| | - Toshiharu Yokoyama
- Accel
Program, Japan Science and Technology Agency (JST), 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan
| | - Hideo Hosono
- Frontier
Research Center, Tokyo Institute of Technology, 4259-S2-13 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan
- Materials
and Structures Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan
- Materials
Research Center for Element Strategy, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan
- Accel
Program, Japan Science and Technology Agency (JST), 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan
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17
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Lei H, Yamaura JI, Guo J, Qi Y, Toda Y, Hosono H. Layered compounds BaM2Ge4Ch6 (M = Rh, Ir and Ch = S, Se) with pyrite-type building blocks and Ge-Ch heteromolecule-like anions. Inorg Chem 2014; 53:5684-91. [PMID: 24816074 DOI: 10.1021/ic500437k] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The structures and chemical features of layered compounds BaM2Ge4Ch6 (M = Rh, Ir; Ch = S, Se) synthesized by high-pressure and high-temperature methods have been systematically studied. These compounds crystallize in an orthorhombic phase with space group Pbca (No. 61). These compounds have the remarkable structural feature of M-Ge-Ch pyrite-type building units, stacking with Ba-Ch layers alternatively along the c axis. It is very rare and novel that pyrite-type subunits are the building blocks in layered compounds. Theoretical calculations and experimental results indicate that there are strongly polarized covalent bonds between Ge and Ch atoms, forming heteromolecule-like anions in these compounds. Moreover, Ge atoms in this structure exhibit an unusual valence state (∼+1) due to the tetrahedral coordination environment of Ge atoms along with M and Ch atoms simultaneously.
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Affiliation(s)
- Hechang Lei
- Frontier Research Center, Tokyo Institute of Technology , Yokohama 226-8503, Japan
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18
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Takashima H, Kurita A, Toda Y, Watanabe A, Waseda K, Kosaka T, Ando H, Sakurai S, Kato D, Amano T. Impact of right atrial pressure as venous pressure on fractional flow reserve calculation in patients with hemodialysis. Eur Heart J 2013. [DOI: 10.1093/eurheartj/eht309.p3970] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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19
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Mori T, Kajihara K, Kanamura K, Toda Y, Hiramatsu H, Hosono H. Indium-Based Ultraviolet-Transparent Electroconductive Oxyfluoride InOF: Ambient-Pressure Synthesis and Unique Electronic Properties in Comparison with In2O3. J Am Chem Soc 2013; 135:13080-8. [DOI: 10.1021/ja405889m] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Tatsuya Mori
- Department of Applied Chemistry,
Graduate School of Urban Environmental Sciences, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji
192-0397, Japan
| | - Koichi Kajihara
- Department of Applied Chemistry,
Graduate School of Urban Environmental Sciences, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji
192-0397, Japan
| | - Kiyoshi Kanamura
- Department of Applied Chemistry,
Graduate School of Urban Environmental Sciences, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji
192-0397, Japan
| | - Yoshitake Toda
- Materials and Structures Laboratory & Frontier Research Center, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan
| | - Hidenori Hiramatsu
- Materials and Structures Laboratory & Frontier Research Center, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan
| | - Hideo Hosono
- Materials and Structures Laboratory & Frontier Research Center, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan
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20
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Lee K, Kim SW, Toda Y, Matsuishi S, Hosono H. Dicalcium nitride as a two-dimensional electride with an anionic electron layer. Nature 2013; 494:336-40. [DOI: 10.1038/nature11812] [Citation(s) in RCA: 314] [Impact Index Per Article: 28.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2012] [Accepted: 11/20/2012] [Indexed: 11/09/2022]
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21
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Kimura K, Sawada K, Kushima H, Toda Y. Influence of Chemical Composition and Heat Treatment on Long-term Creep Strength of Grade 91 Steel. ACTA ACUST UNITED AC 2013. [DOI: 10.1016/j.proeng.2013.03.211] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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22
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Hayashi F, Toda Y, Kanie Y, Kitano M, Inoue Y, Yokoyama T, Hara M, Hosono H. Ammonia decomposition by ruthenium nanoparticles loaded on inorganic electride C12A7:e−. Chem Sci 2013. [DOI: 10.1039/c3sc50794g] [Citation(s) in RCA: 108] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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23
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Toda Y, Hirayama H, Kuganathan N, Torrisi A, Sushko PV, Hosono H. Activation and splitting of carbon dioxide on the surface of an inorganic electride material. Nat Commun 2013; 4:2378. [PMID: 23986101 PMCID: PMC3763491 DOI: 10.1038/ncomms3378] [Citation(s) in RCA: 130] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2013] [Accepted: 07/31/2013] [Indexed: 11/29/2022] Open
Abstract
Activation of carbon dioxide is the most important step in its conversion into valuable chemicals. Surfaces of stable oxide with a low work function may be promising for this purpose. Here we report that the surfaces of the inorganic electride [Ca24Al28O64](4+)(e(-))4 activate and split carbon dioxide at room temperature. This behaviour is attributed to a high concentration of localized electrons in the near-surface region and a corrugation of the surface that can trap oxygen atoms and strained carbon monoxide and carbon dioxide molecules. The [Ca24Al28O64](4+)(e(-))4 surface exposed to carbon dioxide is studied using temperature-programmed desorption, and spectroscopic methods. The results of these measurements, corroborated with ab initio simulations, show that both carbon monoxide and carbon dioxide adsorb on the [Ca24Al28O64](4+)(e(-))4 surface at RT and above and adopt unusual configurations that result in desorption of molecular carbon monoxide and atomic oxygen upon heating.
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Affiliation(s)
- Yoshitake Toda
- Frontier Research Center, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan
| | - Hiroyuki Hirayama
- Department of Materials Science and Engineering, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan
| | - Navaratnarajah Kuganathan
- Department of Physics and Astronomy and the London Centre for Nanotechnology, University College London, Gower Street, London WC1E 6BT, UK
| | - Antonio Torrisi
- Department of Physics and Astronomy and the London Centre for Nanotechnology, University College London, Gower Street, London WC1E 6BT, UK
| | - Peter V. Sushko
- Department of Physics and Astronomy and the London Centre for Nanotechnology, University College London, Gower Street, London WC1E 6BT, UK
| | - Hideo Hosono
- Frontier Research Center, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan
- Materials Research Center for Element Strategy, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan
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24
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Yanagi H, Kuroda T, Kim KB, Toda Y, Kamiya T, Hosono H. Electron injection barriers between air-stable electride with low work function, C12A7:e−, and pentacene, C60 and copper phthalocyanine. ACTA ACUST UNITED AC 2012. [DOI: 10.1039/c2jm14966d] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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25
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Mori T, Mori K, Fujii E, Toda Y, Miyazaki M, Harada M, Kagami S. Neuroradiological and neurofunctional examinations for patients with 22q11.2 deletion. Neuropediatrics 2011; 42:215-21. [PMID: 22131192 DOI: 10.1055/s-0031-1295479] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
Abstract
Since the neuroradiological features of patients with 22q11.2 deletion syndrome are not well-understood, examinations using functional imaging were performed in this study. Brain magnetic resonance imaging (MRI) and 1H-magnetic resonance spectroscopy (MRS) were performed using a clinical 3-Tesla MR imager in 4 patients with 22q11.2 deletion syndrome (2 boys and 2 girls; aged 2-6 years.) and 20 age- and sex-matched healthy control subjects. Furthermore, interictal 123I-iomazenil (IMZ) single photon emission computed tomography (SPECT) was examined in 2 of the 4 patients. Among the 4 patients with 22q11.2 deletion syndrome, 2 patients showed polymicrogyria and 1 patient showed agyria. Those patients with brain malformations also showed abnormal brain artery patterns and decreased accumulation of IMZ in 123I-IMZ SPECT. Although all 4 patients showed epileptic discharges in their electroencephalograms (EEG), one patient with polymicrogyria had no seizure episodes. Decreases in γ-aminobutyric acid (GABA) corresponding to the areas of polymicrogyria and/or epileptic discharges in EEG were shown in all patients except for the patient with agyria. Although consistent evidence was not seen in patients with 22q11.2 deletion syndrome in this study, brain malformations and disturbances of the GABAergic nervous system would be underlying mechanisms of the neurodevelopmental abnormalities in this syndrome.
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Affiliation(s)
- T Mori
- Department of Pediatrics, Institute of Health Bioscience, The University of Tokushima Graduate School, Japan.
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26
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Toda Y, Mertelj T, Naito T, Mihailovic D. Femtosecond carrier relaxation dynamics and photoinduced phase separation in κ-(BEDT-TTF)2Cu[N(CN)2]X (X=Br,Cl). Phys Rev Lett 2011; 107:227002. [PMID: 22182038 DOI: 10.1103/physrevlett.107.227002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2011] [Indexed: 05/31/2023]
Abstract
We investigate the relaxation dynamics of nonequilibrium carriers in organic conductors κ-(BEDT-TTF)(2)Cu[N(CN)(2)]X (X=Br and Cl) using ultrafast time-resolved optical spectroscopy. The dynamics for both salts show similar temperature dependences, which is well characterized by the carrier relaxation across the pseudogap (PG) of the magnitude Δ(PG) ≈ 16 meV for Br salt and 7.0 meV for Cl salt. On the other hand, only the Br salt shows an abrupt increase of the decay time at low temperature, indicating an additional decay component associated with the superconducting (SC) gap below T(c). The fluence dependent dynamics at low temperature evidences the superposition of the SC component onto the PG component. These results indicate a metallic-insulating phase separation in the Br salt triggered by photoexcited nonequilibrium carriers.
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Affiliation(s)
- Y Toda
- Complex Matter Department, Jozef Stefan Institute, Jamova 39, Ljubljana, SI-1000, Slovenia
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27
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Toda Y, Kubota Y, Hirano M, Hirayama H, Hosono H. Surface of room-temperature-stable electride [Ca24Al28O64]4+(e-)4: preparation and its characterization by atomic-resolution scanning tunneling microscopy. ACS Nano 2011; 5:1907-1914. [PMID: 21361301 DOI: 10.1021/nn102839k] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The nanocage compound crystal [Ca24Al28O64]4+(e-)4 (C12A7:e-) is a room-temperature-stable electride. Although bulk C12A7:e- exhibits metallic conduction, the surface of an as-prepared sample or one prepared by mechanical fracture in ultrahigh vacuum is almost insulating and exhibits distinct non-ohmic contact. We studied whether the intrinsic surface of this electride exhibits metallic conduction or not by examining various conditions for preparing the intrinsic surface. A combination of sputtering with thermal annealing led to the emergence of metallic conductivity in a specific condition. Suitably prepared surfaces revealed ohmic contact even in an ambient atmosphere. Atomic-resolution scanning tunneling microscopy (STM) images of the surfaces were consistent with a structural model in which the cage structure in the bulk C12A7:e- electride is conserved at the surface.
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Affiliation(s)
- Yoshitake Toda
- Frontier Research Center and Material and Structure Laboratory, Department of Materials Science and Engineering, Tokyo Institute of Technology, Yokohama, Japan
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28
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Sushko PV, Shluger AL, Toda Y, Hirano M, Hosono H. Models of stoichiometric and oxygen-deficient surfaces of subnanoporous 12CaO·7Al
2
O
3. Proc Math Phys Eng Sci 2011. [DOI: 10.1098/rspa.2010.0560] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Surface structures of stoichiometric and oxygen-deficient complex subnanoporous oxide 12CaO·7Al
2
O
3
(C12A7) are generated by simulating lattice rupture under the influence of an external strain. Extra-framework anions are found to serve as buffers, maintaining stability of the lattice cages in both elastic and inelastic stretching regimes. Modification of the local atomic structure in the near-surface region reduces the band gap in stoichiometric insulating C12A7. On the contrary, the band gap appears in the oxygen-deficient form of C12A7, which is metallic in the bulk. This is due to formation of the surface electron traps, which differ both in the type of the local atomic structure and stability of the electronic states. The implications of this electronic structure for the surface chemical and electron emission properties are discussed.
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Affiliation(s)
- Peter V. Sushko
- Department of Physics and Astronomy and London Centre for Nanotechnology, University College London, Gower Street, London WC1E 6BT, UK
- WPI Advanced Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba, Sendai 980-8577, Japan
| | - Alexander L. Shluger
- Department of Physics and Astronomy and London Centre for Nanotechnology, University College London, Gower Street, London WC1E 6BT, UK
- WPI Advanced Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba, Sendai 980-8577, Japan
| | - Yoshitake Toda
- Frontier Research Center, Tokyo Institute of Technology, Yokohama 226-8503, Japan
| | - Masahiro Hirano
- Frontier Research Center, Tokyo Institute of Technology, Yokohama 226-8503, Japan
| | - Hideo Hosono
- Frontier Research Center, Tokyo Institute of Technology, Yokohama 226-8503, Japan
- Materials and Structures Laboratory, Tokyo Institute of Technology, Yokohama 226-8503, Japan
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29
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Ishioka J, Liu YH, Shimatake K, Kurosawa T, Ichimura K, Toda Y, Oda M, Tanda S. Chiral charge-density waves. Phys Rev Lett 2010; 105:176401. [PMID: 21231061 DOI: 10.1103/physrevlett.105.176401] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2010] [Indexed: 05/02/2023]
Abstract
We discovered the chirality of charge-density waves (CDW) in 1T-TiSe₂ by using STM and time-domain optical polarimetry. We found that the CDW intensity becomes Ia₁∶Ia₂∶Ia₃ = 1∶0.7 ± 0.1∶0.5 ± 0.1, where Ia(i) (i=1,2,3) is the amplitude of the tunneling current contributed by the CDWs. There were two states, in which the three intensity peaks of the CDW decrease clockwise and anticlockwise. The chirality in CDW results in the threefold symmetry breaking. Macroscopically, twofold symmetry was indeed observed in optical measurement. We propose the new generalized CDW chirality H(CDW) ≡ q₁·(q₂×q₃), where q(i) are the CDW q vectors, which is independent of the symmetry of components. The nonzero H(CDW)-the triple-q vectors do not exist in an identical plane in the reciprocal space-should induce a real-space chirality in CDW system.
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Affiliation(s)
- J Ishioka
- Department of Applied Physics, Hokkaido University, Sapporo, Japan
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30
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Abstract
We study the dynamics of a paired optical vortex (OV) generated by second-harmonic generation (SHG) using sub-picosecond pulses. By changing the position of a thin nonlinear crystal along the propagation direction, we observe a rotation of two vortices with changing separation distance. The dynamics is well explained by SHG with a beam walk-off, which introduces a contamination of zero-order Laguerre-Gaussian beam (LG(0)) together with topological charge doubling. The quantitative analysis indicates that the rotation angle of the OVs manifests the Gouy phase while the splitting provides the walk-off angle of the crystal. We also show that the subtraction of LG(0) is realized by the superposition of LG(0) with an anti-balanced phase in the pump.
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Affiliation(s)
- Y Toda
- Department of Applied Physics, Hokkaido University, N13W8 Kita-ku, Sapporo, Japan.
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31
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Naito T, Matsuo S, Inabe T, Toda Y. Carrier dynamics in an organic magnetic superconductor and related salts κ, λ-(BETS)(2)MCl(4) (M = Fe, Ga). J Phys Condens Matter 2010; 22:185701. [PMID: 21393688 DOI: 10.1088/0953-8984/22/18/185701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
In order to compare the carrier dynamics and reveal the origin of differences in their electrical behaviour, time-resolved reflectivity changes were measured on single crystals of the title compounds. The observed relaxation behaviour explained well their electrical behaviour, and indicated that different conduction mechanisms dominated κ- and λ-type BETS salts, irrespective of local spins, at about 8-100 K; the electrical behaviour of the κ-type salts is governed by relaxation times of carriers and/or density of states at the Fermi levels, while that of the λ-type salts is dominated by the latter.
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Affiliation(s)
- T Naito
- Graduate School of Science, Hokkaido University, Kita 10, Nishi 8, Kita-ku, Sapporo 060-0810, Japan.
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32
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Ueno Y, Toda Y, Adachi S, Morita R, Tawara T. Coherent transfer of orbital angular momentum to excitons by optical four-wave mixing. Opt Express 2009; 17:20567-20574. [PMID: 19997285 DOI: 10.1364/oe.17.020567] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We demonstrate the coherent transfer of optical orbital angular momentum (OAM) to the center of mass momentum of excitons in semiconductor GaN using a four-wave mixing (FWM) process. When we apply the optical vortex (OV) as an excitation pulse, the diffracted FWM signal exhibits phase singularities that satisfy the OAM conservation law, which remain clear within the exciton dephasing time (approximately 1ps). We also demonstrate the arbitrary control of the topological charge in the output signal by changing the OAM of the input pulse. The results provide a way of controlling the optical OAM through carriers in solids. Moreover, the time evolution of the FWM with OAM leads to the study of the closed-loop carrier coherence in materials.
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Affiliation(s)
- Y Ueno
- 1Department of Applied Physics, Hokkaido University, N13W8 Kita-ku, Sapporo, Japan
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33
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Matsumoto N, Sato K, Yoshida K, Hashimoto K, Toda Y. Preparation and characterization of beta-tricalcium phosphate co-doped with monovalent and divalent antibacterial metal ions. Acta Biomater 2009; 5:3157-64. [PMID: 19435618 DOI: 10.1016/j.actbio.2009.04.010] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2008] [Revised: 03/24/2009] [Accepted: 04/17/2009] [Indexed: 11/26/2022]
Abstract
Ag(+) and Zn(2+) or Cu(2+) ions were co-doped with beta-tricalcium phosphate (AgZn-TCP and AgCu-TCP), and their substitution models, antimicrobial activities, mechanisms and cytotoxicities were investigated. The lattice constants (a-axis and c-axis) of AgZn-TCP and AgCu-TCP decreased linearly with the amount of Zn(2+) or Cu(2+) ions up to 9.09 mol.%, which indicated that Ag(+) ions were doped at the Ca(4) site and a vacancy in the beta-TCP structure, and Zn(2+) or Cu(2+) ions were doped at the Ca(5) site. Antibacterial activities of AgZn-TCP and AgCu-TCP on Escherichia coli and Staphylococcus aureus were higher than those of Ag(+) ions-doped beta-TCP (Ag-TCP) and pure beta-TCP. These antimicrobial activities suggested that an interaction occurred between bacteria and Ag(+), Zn(2+) and Cu(2+) ions eluted from AgZn-TCP and AgCu-TCP and between bacteria and the free radicals generated by antibacterial agents or in bacterial cells. AgZn-TCP and AgCu-TCP can be used over long periods of time with high antimicrobial activity, because the rate at which Ag(+) ions are released from AgZn-TCP and AgCu-TCP is slower than that at which Ag(+) ions are released from Ag-TCP. However, it is necessary to determine the suitable amounts of Ag(+), Zn(2+) and Cu(2+) ions in AgZn-TCP and AgCu-TCP by considering both their antimicrobial activities and cytotoxicities, because beta-TCP doped with a large amount of these metal ions exhibits cytotoxicity. Furthermore, AgZn-TCP and AgCu-TCP are considered to be promising materials for use in various fields.
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34
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Dhar SK, Kulkarni R, Hidaka H, Toda Y, Kotegawa H, Kobayashi TC, Manfrinetti P, Provino A. Pressure and magnetic field tuned quantum critical point in the Kondo antiferromagnet CePtZn. J Phys Condens Matter 2009; 21:156001. [PMID: 21825376 DOI: 10.1088/0953-8984/21/15/156001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We report magnetization, heat capacity and electrical resistivity measurements on CePtZn, which crystallizes in the orthorhombic TiNiSi type structure. Magnetization and electrical resistivity on the iso-structural series of compounds Ce(1-x)La(x)PtZn (x = 0.1, 0.2 0.5 and 1) were also carried out. The electrical resistivity of CePtZn was also measured in external magnetic fields up to 12 T and under pressures up to 2.66 GPa. We find that CePtZn is a dense Kondo lattice, ordering antiferromagnetically at T(N) = 1.7 K, with a comparable Kondo temperature. The magnetic transition temperature, T(N), is continuously suppressed both by the magnetic field and pressure and [Formula: see text] around 5-6 T and at 1.2 GPa, respectively. Non-Fermi liquid behavior of resistivity at 4 T and 1.2 GPa and logarithmic divergence of the heat capacity, C(4f)/T, at 6 T in a limited temperature region strongly suggest the emergence of a quantum critical point as [Formula: see text].
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Affiliation(s)
- S K Dhar
- CMP&MS, TIFR, Homi Bhabha Road, Colaba, Mumbai 400 005, India
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Liu YH, Toda Y, Shimatake K, Momono N, Oda M, Ido M. Direct observation of the coexistence of the pseudogap and superconducting quasiparticles in Bi2Sr2CaCu2O8 + y by time-resolved optical spectroscopy. Phys Rev Lett 2008; 101:137003. [PMID: 18851484 DOI: 10.1103/physrevlett.101.137003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2008] [Indexed: 05/26/2023]
Abstract
We report the ultrafast optical response of quasiparticles (QPs) in both the pseudogap (PG) and superconducting (SC) states of an underdoped Bi2Sr2CaCu2O8 + y (Bi2212) single crystal measured with the time-resolved pump-probe technique. At a probe energy variant planck's over omegapr = 1.55 eV, it is found that the reflectivity change DeltaR/R changes its sign at exactly Tc, which allows the direct separation of the charge dynamics of PG and SC QPs. Further systematic investigations indicate that the transient signals associated with PG and SC QPs depend on the probe beam energy and polarization. By tuning them below Tc, two distinct components can be detected simultaneously, providing evidence for the coexistence of PG and SC QPs.
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Affiliation(s)
- Y H Liu
- Department of Physics, Hokkaido University, Sapporo 060-0810, Japan.
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Egi M, Morimatsu H, Toda Y, Matsusaki T, Suzuki S, Shimizu K, Iwasaki T, Takeuchi M, Bellomo R, Morita K. Hyperglycemia and the outcome of pediatric cardiac surgery patients requiring peritoneal dialysis. Int J Artif Organs 2008; 31:309-16. [PMID: 18432586 DOI: 10.1177/039139880803100406] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
OBJECTIVE To study the nature of the association between glycemia and ICU mortality in pediatric cardiac surgery patients treated with peritoneal dialysis (PD). MATERIALS AND METHODS Retrospective observational study in the ICU of a tertiary hospital involving forty pediatric cardiac surgery patients treated with PD. We selected patients requiring PD, extracted glucose measurements and nutritional intake data during ICU stay and calculated mean and maximum blood glucose values i) during ICU stay; ii) during dependence on PD; and iii) during independence from PD. We statistically assessed the relationship between glycemia-related variables and ICU mortality. MEASUREMENTS AND RESULTS Twenty-two patients treated with PD died (mortality 55%). In the PD cohort, 9725 blood glucose measurements were performed (every 3.3 hours on average). The mean glycemia during dependence on PD was significantly higher in non-survivors than survivors (p<0.0001), but not during independence from PD (p=0.49). The area under the receiver operator characteristic curve for the mean glycemia during dependence on PD was significantly greater than that obtained during independence from PD. Even after adjustment for severity of illness using multivariate logistic analysis, the mean glycemia and calorie intake during PD were significant and independent predictors of ICU mortality. CONCLUSIONS A higher mean blood glucose concentration during PD, but not during PD-free periods was associated with greater ICU mortality. Mean glycemia and calorie intake during PD were significant and independent predictors of ICU mortality.
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Affiliation(s)
- M Egi
- Department of Anesthesiology and Resuscitology, Okayama University Medical School, Okayama, Japan.
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Toda Y, Tsukimura N. A comparison of intra-articular hyaluronan injection accuracy rates between three approaches based on radiographic severity of knee osteoarthritis. Osteoarthritis Cartilage 2008; 16:980-5. [PMID: 18339561 DOI: 10.1016/j.joca.2008.01.003] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2007] [Accepted: 01/06/2008] [Indexed: 02/02/2023]
Abstract
OBJECTIVE To compare the accuracy rates of intra-articular hyaluronic acid (HA) injections for osteoarthritis (OA) of the knee between the modified Waddell approach (an anteromedial approach with manipulative ankle traction at 30 degrees of knee flexion), an anteromedial approach with the subjects seated (hereinafter the seated anteromedial approach) and a lateral patellar approach based on the Kellgren-Lawrence (K-L) radiographic grade (II, III and IV). DESIGNS Fifty patients with knee OA received HA injections through the three approaches. The accuracy rates were confirmed with a single radiograph after injections of a mixture of radiographic contrast medium. RESULTS In the K-L grade IV cases (n=11), the accuracy rates through the modified Waddell approach (11 out of 11, 100%) were significantly higher than those through the seated anteromedial approach (six out of 11, 55%) and the lateral patellar approach (six out of 11, 55%) (P=0.035). No significant differences were detected in the accuracy rates of the participants classified as grade II (n=21) or III (n=18) cases between the modified Waddell approach (86% and 78%, respectively), the seated anteromedial approach (71% and 56%, respectively) and the lateral patellar approach (86% and 61%, respectively) (P>0.05). CONCLUSION Although previous studies have been conducted on the accuracy of needle placement into the intra-articular space of the knee, no evaluations were performed with the results categorized by radiographic severity. This study highlighted the need for clinicians to change the approach employed for HA injections, according to the severity of knee OA.
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Affiliation(s)
- Y Toda
- Toda Orthopedic Rheumatology Clinic, Suita, Osaka, Japan.
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38
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Toda Y, Tsukimura N. Influence of concomitant heeled footwear when wearing a lateral wedged insole for medial compartment osteoarthritis of the knee. Osteoarthritis Cartilage 2008; 16:244-53. [PMID: 17693101 DOI: 10.1016/j.joca.2007.06.010] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2007] [Accepted: 06/13/2007] [Indexed: 02/02/2023]
Abstract
OBJECTIVE To compare the influence of concomitant heeled footwear when wearing a lateral wedged insole for medial compartment of osteoarthritis (OA) of the knee, between everyday walking shoes for outdoor use and socks or flat footwear without a heel for indoor use. DESIGN A total of 227 outpatients were prospectively randomized and treated with a neutral wedged insole inserted into shoes (placebo with shoes; n=45), a wedged insole inserted into shoes (inserted insole with shoes; n=45), a sock-type ankle supporter with a wedged insole when wearing socks or flat footwear (inserted insole without shoes; n=46), a subtalar strapped insole when wearing shoes (strapped insole with shoes; n=45), and the strapped insole with socks or flat footwear (strapped insole without shoes; n=46). The Lequesne index of knee OA at week 12 was compared with the baseline in each treatment group. RESULTS Twenty patients withdrew from the study, and the 207 patients who completed the 12-week study were evaluated. At the final assessment, participants wearing the inserted insole without shoes (P=0.003), the strapped insole with shoes (P<0.0001), and the strapped insole without shoes (P<0.0001) demonstrated significantly improved Lequesne index scores in comparison with their baseline assessments. No significant differences were found in the placebo (P=0.16) or the inserted insole with shoes (P=0.2) groups. CONCLUSION Concomitant heeled footwear may decrease the efficacy of an inserted lateral wedged insole. The optimal usage of a lateral wedged insole for knee OA would be the combination with socks or flat footwear without heels.
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Affiliation(s)
- Y Toda
- Toda Orthopedic Rheumatology Clinic, Suita, Osaka, Japan.
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39
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Buchammagari H, Toda Y, Hirano M, Hosono H, Takeuchi D, Osakada K. Room Temperature-Stable Electride as a Synthetic Organic Reagent: Application to Pinacol Coupling Reaction in Aqueous Media. Org Lett 2007; 9:4287-9. [PMID: 17854199 DOI: 10.1021/ol701885p] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Room temperature-stable inorganic electride [Ca(24)Al(28)O(68)](4+)4e(-) was employed for a pinacol coupling reaction in aqueous media. Ca-Al-O gel formed by the destruction of the crystal structure of an electride by water media played a key role in transferring the electron to electrophilic aldehydes. Aromatic aldehydes reacted smoothly with moderate to high yields.
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Affiliation(s)
- Haritha Buchammagari
- Frontier Collaborative Research Center and Chemical Resources Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta, Yokohama 226-8503, Japan
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40
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Toda Y, Matsuki N, Shibuya M, Fujioka I, Tamahara S, Ono K. Glial fibrillary acidic protein (gfap
) and anti-gfap
autoantibody in canine necrotising meningoencephalitis. Vet Rec 2007; 161:261-4. [PMID: 17720962 DOI: 10.1136/vr.161.8.261] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
To establish clinical markers for canine necrotising meningoencephalitis (NME) and to elucidate its pathogenesis, glial fibrillary acidic protein (GFAP) and anti-GFAP autoantibodies were measured in the cerebrospinal fluid (CSF) of 32 dogs with NME, 23 dogs with other inflammatory central nervous system (CNS) diseases, 27 dogs with miscellaneous CNS diseases and 25 healthy dogs, including five pugs. The dogs with NME had the highest levels of anti-GFAP autoantibodies. The diagnostic sensitivity and specificity of anti-GFAP autoantibodies for NME were 91 per cent and 73 per cent, respectively. Some of the dogs with NME and the healthy pugs, had high CSF concentrations of GFAP, suggesting a breed-specific fragility of astrocytes. The leakage of GFAP and the development of autoimmunity may be key to understanding the pathogenesis of NME.
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Affiliation(s)
- Y Toda
- Laboratory of Veterinary Clinical Pathobiology, Department of Veterinary Medical Sciences, Graduate School of Agricultural and Life Sciences, University of Tokyo, 1-1-1 Yayoi, Tokyo 113-8657, Japan
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Abstract
Interspersed repetitive sequences are major components of eukaryotic genomes. They comprise about 50% of the mammalian genome. They interact with the whole genome and influence its evolution. They do this in many ways, e.g. by serving as recombination hotspots, providing a mechanism for genomic shuffling and a source of 'ready-to-use' motifs for new transcriptional regulatory elements, polyadenylation signals, and protein-coding sequences. In this review we discuss the consequences of exaptation of sequences originated in tansposable elements with focus on events that influence protein coding genes.
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Affiliation(s)
- W Maka Owski
- Institute of Molecular Evolutionary Genetics and Department of Biology, The Pennsylvania State University, University Park, Ill. USA
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42
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Kobayashi M, Ohira T, Toda Y, Akiyama T, Orii M, Kawase T. TP1.1 Correlation between intracortical inhibition and clinical symptoms in Parkinson’s disease: TMS study of patients with deep brain stimulation. Clin Neurophysiol 2006. [DOI: 10.1016/j.clinph.2006.06.156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Sasaki T, Takahashi T, Maeshima K, Shimizu H, Toda Y, Morimatsu H, Takeuchi M, Yokoyama M, Akagi R, Morita K. Heme Arginate Pretreatment Attenuates Pulmonary NF-κB and AP-1 Activation Induced by Hemorrhagic Shock via Heme Oxygenase-1 Induction. Med Chem 2006; 2:271-4. [PMID: 16948473 DOI: 10.2174/157340606776930781] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Hemorrhagic shock followed by resuscitation (HSR) induces oxidative stress that leads to acute lung injury. Heme oxygenase-1 (HO-1), the rate-limiting enzyme in heme catabolism, is induced by oxidative stress and is thought to play an important role in the protection from oxidative tissue injuries. We previously demonstrated that HO-1 induction by heme arginate (HA), a strong inducer of HO-1, ameliorated HSR-induced lung injury and inflammation. Cellular redox state is known to modulate the DNA biding activity of the transcription factors; nuclear factor-kappaB (NF-kappaB) and activator protein-1 (AP-1). In the present study, we treated rats with HA (30 mg/kg of hemin) 18 h prior to HSR and examined its effect on the DNA binding activity of NF-kappaB and AP-1 at 1.5 h after HSR. HSR significantly increased the DNA binding activity of NF-kappaB as well as AP-1, while HA pretreatment markedly attenuated the activities of these transcription factors. In contrast, administration of tin mesoporphyrin, a specific competitive inhibitor of HO activity, to HA-pretreated animals abolished the suppressive effect of HA on the activities of NF-kappaB and AP-1, and increased these activities to almost the same level as those in HSR animals. Our findings indicate that HA pretreatment can significantly suppress the increased activity of NF-kappaB and AP-1 induced by HSR by virtue of its ability to induce HO-1. Our findings also suggest that HO-1 induced by HA pretreatment ameliorates HSR-induced lung injury at least in part mediated through the suppression of the activities of these transcription factors.
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Affiliation(s)
- T Sasaki
- Department of Anesthesiology and Resuscitology, Okayama University Graduate School of Medicine and Dentistry, Japan
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Kogure S, Toda Y, Tsukahara S. Prediction of future scotoma on conventional automated static perimetry using frequency doubling technology perimetry. Br J Ophthalmol 2006; 90:347-52. [PMID: 16488960 PMCID: PMC1856953 DOI: 10.1136/bjo.2005.077065] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
AIM To see if scotoma detected with frequency doubling technology (FDT) is confirmed by Humphrey field analyser (HFA) 3 years later. METHODS Subjects were first examined with the screening C-20-1 program of FDT. The visual field was examined annually for 4 years using HFA program C30-2. The central 58 test points in HFA were assigned to one of the 17 clusters corresponding to FDT test points. Each cluster was represented as the lowest probability symbol of total deviation (TD) of the HFA test points included in the cluster. Clusters were graded normal, suspected scotoma, and scotoma depending on probability of TD-5% or more, 5%-1%, less than 1%, respectively. Relative risk (RR) of abnormality on FDT for future scotoma on HFA was estimated. RESULTS 80 eyes of 42 patients were followed up for 4 years. While 4.0% of normal clusters of HFA with normal FDT results developed into scotoma cluster, 20.8% of normal clusters with abnormal FDT results developed into scotoma cluster with HFA at the third year. RR for future scotoma was 5.24 (95% CI, 2.75 to 10.0, p<0.05). CONCLUSION An abnormal result in FDT shows a high risk of future scotoma on HFA after 3 years even if the original HFA perimetry showed normal results.
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Affiliation(s)
- S Kogure
- Department of Ophthalmology, University of Yamanashi, Tamaho, Yamanashi 409-3898, Japan.
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45
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Toda Y, Tsukimura N. A 2-year follow-up of a study to compare the efficacy of lateral wedged insoles with subtalar strapping and in-shoe lateral wedged insoles in patients with varus deformity osteoarthritis of the knee. Osteoarthritis Cartilage 2006; 14:231-7. [PMID: 16271485 DOI: 10.1016/j.joca.2005.09.006] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2005] [Accepted: 09/21/2005] [Indexed: 02/02/2023]
Abstract
OBJECTIVE This study was conducted in order to assess the effect of wearing a lateral wedged insole with a subtalar strap for 2 years in patients with osteoarthritis varus deformity of the knee (knee OA). DESIGN The setting was an outpatient clinic. The efficacies of the strapped insole and a traditional shoe insert wedged insole (the inserted insole), as a positive control, were compared at the baseline and after 2 years of treatment. Randomization was performed according to birth date. The 61 female outpatients with knee OA who completed a prior 6-month study were asked to wear their respective insoles continuously as treatment during the course of the 2-year study. The femorotibial angle (FTA) was assessed by standing radiographs obtained while the subjects were barefoot and the Lequesne index of the knee OA at 2 years was compared with those at baseline in each insole group. RESULTS There were 61 patients in the original study, but 13 patients (21.3%) did not want to wear the insole continuously and five (8.2%) withdrew for other reasons. The 42 patients who completed the 2-year study were evaluated. At the 2-year assessment, participants wearing the subtalar strapped insole (n=21) demonstrated significantly decreased FTA (P=0.015), and significantly improved Lequesne index (P=0.031) in comparison with their baseline assessments. These significant differences were not found in the group with the traditional shoe inserted wedged insole (n=21). CONCLUSION Only those participants using the subtalar strapped insole demonstrated significant change in the FTA in comparison with the baseline assessments. If the insole with a subtalar strap maintains FTA for more than 2 years, it may restrict the progression of degenerative articular cartilage lesions of knee OA.
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Affiliation(s)
- Y Toda
- Toda Orthopedic Rheumatology Clinic, Suita, Osaka, Japan.
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Nabae K, Ichihara T, Hagiwara A, Hirota T, Toda Y, Tamano S, Nishino M, Ogasawara T, Sasaki Y, Nakamura M, Shirai T. A 90-day oral toxicity study of beta-carotene derived from Blakeslea trispora, a natural food colorant, in F344 rats. Food Chem Toxicol 2005; 43:1127-33. [PMID: 15833388 DOI: 10.1016/j.fct.2005.03.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2004] [Revised: 02/21/2005] [Accepted: 03/01/2005] [Indexed: 10/25/2022]
Abstract
A subchronic oral toxicity study of beta-carotene derived from Blakeslea trispora, a natural food colorant, was performed with groups of 10 male and 10 female F344 rats fed the agent at dietary levels of 0%, 0.2%, 1.0% and 5.0% for 90 days. There were no treatment-related adverse effects with regard to body weight, food and water consumption, urinalysis, ophthalmology, hematology, serum biochemistry, and organ weight data. On clinical observation, red coloring of fur was noted in both sexes of the 1.0% and 5.0% group rats, with red feces observed in all treated group animals, and necropsy revealed all rats of the treated groups to have reddish coloration of the contents of the gastro-intestinal tract, due to the pigmentation and thus lacking toxicological significance. On histopathological examination, sporadic spontaneous lesions known to occur in this strain of rats were the only findings, with no specific relation to the test substance. Thus, the no-observed-adverse-effect-level (NOAEL) was judged to be a dietary level of at least 5.0% (3127 mg/kg body weight/day for males, 3362 mg/kg body weight/day for females) for beta-carotene derived from B. trispora under the present experimental conditions.
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Affiliation(s)
- K Nabae
- DIMS Institute of Medical Science, Inc., 64 Goura, Nishiazai, Ichinomiya 491-0113, Japan
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Toda Y, Duke T, Shekerdemian LS. Influences on lactate levels in children early after cardiac surgery: prime solution and age. CRIT CARE RESUSC 2005; 7:87-91. [PMID: 16548798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2004] [Accepted: 02/28/2005] [Indexed: 05/07/2023]
Abstract
OBJECTIVE Hyperlactataemia is often seen after cardiac surgery in children and is associated with an increased risk of adverse outcome, especially in infants and young children. However, we noticed that many older children after cardiac surgery had elevated lactate levels in the absence of other markers of oxygen debt or cardiovascular instability and had an uncomplicated postoperative course. Many older children undergo surgery without blood products being used in the cardiopulmonary bypass (CPB) circuit prime. The aim of this study was to determine whether lactate levels in children after CBP are influenced by age and/or pump prime solutions. METHODS We studied 100 children undergoing open heart surgery in a tertiary paediatric cardiac surgical unit. Fifty children were aged 2 months to 4 years (Group 1) and 50 were aged 4 years or older (Group 2). Blood samples were obtained from an arterial catheter and serum lactate levels were collected at the time of admission to the paediatric intensive care unit (PICU) and 4 hours later. The following data were collected from the medical records or laboratory databases: weight, age, lowest haemoglobin during CPB, total bypass time, aortic cross clamp time, priming solution used, length of postoperative ventilation and PICU stay, type of surgery and occurrence of adverse perioperative events, including cardiac arrest, need for extracorporeal support or death. RESULTS All children in Group 1 had a blood prime. All children in Group 2 had a bloodless prime. Although there were differences in the types of anomalies and surgical procedures performed, there were no significant differences between the two groups in terms of surgical complexity, CBP time, aortic cross clamp time and haemoglobin during CPB. Lactate levels in children in Group 2 were higher than in Group 1. Sixteen children (32%) in Group 2 had a lactate level of > 4 mmol/L, whereas only 3 children (6%) in Group 1 had a lactate level of > 4 mmol/L (Fisher's exact test p = 0.0002). Using multivariate analysis the pump prime solution was independently associated with high lactate levels after CPB. CONCLUSIONS Lactate levels after cardiac surgery in older children who have a bloodless prime may not have the same physiological or prognostic implications as in infants who have a blood prime.
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Affiliation(s)
- Y Toda
- Dept of Anesthesiology and Resuscitology, Okayama University Graduate School of Medicine and Dentistry, Japan
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Toda Y, Tsukimura N, Segal N. An optimal duration of daily wear for an insole with subtalar strapping in patients with varus deformity osteoarthritis of the knee. Osteoarthritis Cartilage 2005; 13:353-60. [PMID: 15780649 DOI: 10.1016/j.joca.2004.12.012] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/28/2004] [Accepted: 12/20/2004] [Indexed: 02/02/2023]
Abstract
OBJECTIVE To assess the optimal duration of daily wear for a laterally wedged insole with subtalar strapping in subjects with medial compartment osteoarthritis of the knee (knee OA). DESIGN The setting was an outpatient clinic. Eighty-one patients with knee OA were prospectively randomized according to birth date and to either 2 weeks of treatment with a lateral wedge with subtalar strapping for less than 5 h (the short group), 5-10 h (the medium group) or greater than 10 h (the long group) each day, or to treatment with a subtalar strapping band without lateral wedge (the placebo group). Standing radiographs were used to analyze the femorotibial angle for each subject, both with and without their respective orthotic device. The remission scores of Lequesne index were compared among the four groups at the conclusion. RESULTS The short (n=21), medium (n=20) and long (n=18) groups demonstrated a significant greater valgus correction of the femorotibial angle than the placebo group (n=22) (P<0.0001). The remission score was significantly improved in the medium group compared to the placebo (P=0.001) and long (P=0.001) groups. CONCLUSIONS An optimal duration of insole with subtalar strapping wear for patients with varus deformity knee OA may be between 5 and 10 h each day.
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Affiliation(s)
- Y Toda
- Toda Orthopedic Rheumatology Clinic, Suita, Osaka, Japan.
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Kashiwagi K, Kashiwagi F, Toda Y, Osada K, Tsumura T, Tsukahara S. A newly developed peripheral anterior chamber depth analysis system: principle, accuracy, and reproducibility. Br J Ophthalmol 2004; 88:1030-5. [PMID: 15258020 PMCID: PMC1772280 DOI: 10.1136/bjo.2003.036699] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
AIM To develop a new, non-contact system for measuring anterior chamber depth (ACD) quantitatively, and to investigate its accuracy as well as interobserver and intraobserver reproducibility. METHODS The system scanned the ACD from the optical axis to the limbus in approximately 0.5 second and took 21 consecutive slit lamp images at 0.4 mm intervals. A computer installed program automatically evaluated the ACD, central corneal thickness (CT), and corneal radius of curvature (CRC) instantly. A dummy eye was used for investigating measurement accuracy. The effects of CT and CRC on the measurement results were examined using a computer simulation model to minimise measurement errors. Three examiners measured the ACD in 10 normal eyes, and interobserver and intraobserver reproducibility was analysed. RESULTS The ACD values measured by this system were very similar to theoretical values. Increase of CRC and decrease in CT decreased ACD and vice versa. Data calibration using evaluated CT and CRC successfully reduced measurement errors. Intraobserver and interobserver variations were small. Their coefficient variation values were 7.4% (SD 2.3%) and 6.7% (0.7%), and these values tended to increase along the distance from the optical axis. CONCLUSION The current system can measure ACD with high accuracy as well as high intraobserver and interobserver reproducibility. It has potential use in measuring ACD quantitatively and screening subjects with narrow angle.
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Affiliation(s)
- K Kashiwagi
- Department of Ophthalmology, University of Yamanashi Faculty of Medicine, 1110 Shimokato, Tamaho, Yamanashi 409-3898, Japan.
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Abstract
A layer-doubling method developed in LEED calculation is applied to the ADF-STEM image simulation. This approach makes it possible to simulate image intensities of systems having a repeated slab structure, such as embedded precipitates or defects, with a much higher efficiency because it does not require the diagonalization of repeated slabs. As a simple example of this method, channeling effects are calculated for a system with embedded crystalline displaced slabs for various different slab thicknesses.
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Affiliation(s)
- K Mitsuishi
- National Institute for Materials Science, 3-13 Sakura, Tsukuba 305-0003, Ibaraki, Japan.
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