79 results on '"Miyamoto, Yoshinari"'
Search Results
2. Strategic outsourcing and quality choice: Is a vertical integration model sustainable?
- Author
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Miyamoto, Yoshinari
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VERTICAL integration ,CONTRACTING out ,RECESSIONS ,PRODUCT differentiation - Abstract
This paper uses two versions of a vertical product differentiation model with price competition to investigate how strategic behavior between rival firms influences which organizational production mode each firm adopts: that is, either vertical integration or outsourcing. We show that not only a symmetric configuration, where both high‐ and low‐quality firms outsource, but also an asymmetric configuration, where the high‐quality firm produces in‐house whereas the low‐quality firm outsources, are acceptable as a subgame‐perfect equilibrium outcome. We explore the implications of these results in light of the recent slump in business of Japanese electronics enterprises in the flat‐panel television industry. [ABSTRACT FROM AUTHOR]
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- 2021
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3. Outcomes and component-positioning in total knee arthroplasty may be comparable between supervised trained surgeons and their supervisor.
- Author
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Goto, Kazumi, Katsuragawa, Yozo, and Miyamoto, Yoshinari
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TOTAL knee replacement ,SURGEONS ,SUPERVISORS ,PATIENT positioning - Abstract
Purpose: There are concerns that malalignment in total knee arthroplasty (TKA) occurs with less experienced surgeons. This study investigates the influence of surgical experience on TKA outcomes. Materials and methods: Nineteen patients (38 knees) who underwent bilateral TKA between 2011 and 2015 were included. A supervisor performed knee replacements associated with lower Knee Society Scores (KSS); trainee surgeons operated on the other knee. Knees were categorized into two groups: operations by the supervisor (group S) versus operations by trainee surgeons (group T). Range of motion (ROM), KSS, operative time, hip–knee–ankle angle, and femoral and tibial component angle were evaluated. Results: The mean operative time was 92.5 min in group S and 124.2 min in group T (p < 0.01). The mean postoperative maximal flexion was 113.2° in group S and 114.2° in group T (not significant). The mean postoperative KSS was 92.9 in group S and 93.9 in group T (not significant). No significant differences between groups in terms of proportion of inliers for the hip–knee–ankle angle, femoral component angle, or tibial component angle were observed. Conclusions: Although operative time was significantly longer for trainee surgeons versus the supervisor, no significant differences in ROM, KSS, or component positioning between supervisor and trainee surgeons were observed. Level of evidence: IV (retrospective case series design). [ABSTRACT FROM AUTHOR]
- Published
- 2020
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4. Terahertz wave localization at a three-dimensional ceramic fractal cavity in photonic crystals.
- Author
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Miyamoto, Yoshinari, Kanaoka, Hideaki, and Kirihara, Soshu
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INDUSTRIAL chemistry ,ELECTROMAGNETIC fields ,ELECTRIC fields ,ALUMINUM oxide ,RESONANCE - Abstract
A three-dimensional microphotonic crystal with diamond structure, in which a cube cavity of the stage 2 Menger sponge fractal is embedded, was designed in order to localize effectively terahertz waves. The crystal was fabricated from alumina ceramics by a computer aided design/computar aided manufacturing microstereolithography and sintering process. The localization frequency was in good agreement with both the simulated frequency determined by the transmission line modeling method and the calculated frequency by using the empirical equation. The simulated amplitude distribution of electric field oscillations showed that three different resonance modes exist in substructures of the sponge with each half wavelength oscillation. The wave leakage from the single sponge fractal was effectively blocked by the outer diamond structure. [ABSTRACT FROM AUTHOR]
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- 2008
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5. Synthesis of Ceramic Bonded Carbon Using SiC-Coated Carbon Particles and Spark Plasma Sintering.
- Author
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Nakamura, Masaharu, Tojo, Tetsuro, Naito, Makio, and Miyamoto, Yoshinari
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CERAMIC materials synthesis ,SINTERING ,MICROSTRUCTURE ,PARTICLE size determination ,SILICON carbide ,CHEMICAL reactions ,SURFACE coatings ,PLASMA gases - Abstract
A dense SiC coating on carbon particles has been developed using SiO powders as the Si source and a chemical vapor reaction method. The coating process was controlled by atmosphere, coating temperature, time, and weight ratio of SiO/C. The SiC-coated carbon particles, with a mean particle size of 20 μm, were sintered at 2000°C under 40 MPa for 20 min by spark plasma sintering ( SPS). The product, called ceramic bonded carbon ( CBC), had a unique microstructure, with a 3D micro-network structure consisting of carbon particles covered with 1~5 μm thick SiC boundary layers. The sintering behavior of SiC/ CBCs was analyzed in terms of the network formation of SiC boundary layers at over 1800°C and the grain growth of SiC at 2000°C. SiC/ CBCs showed a bending strength of 150 MPa and a low shore hardness of 40. These materials could also be easily joined to SiC ceramics using SPS. [ABSTRACT FROM AUTHOR]
- Published
- 2012
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6. Joining of AlN to Ceramic Bonded Carbon for Heat Dissipating Substrates.
- Author
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Chen, Weiwu, Tojo, Tetsuro, and Miyamoto, Yoshinari
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CERAMIC materials ,ENERGY dissipation ,SUBSTRATES (Materials science) ,CARBON composites ,THERMAL expansion ,THERMAL conductivity ,STRENGTH of materials - Abstract
Ceramic bonded carbon ( CBC) is a new composite consisting of carbon particles bonded with thin ceramic boundaries. It can not only reinforce carbon but also provide joining capability with other materials. To obtain light-weight heat dissipating substrates with matched low coefficients of thermal expansion, a top layer of AlN and a bottom layer of AlN/ CBC (20 vol% AlN) were sintered and joined in one step by hot-pressing at 1950°C. Both AlN and AlN/ CBC were densified and bonded tightly. AlN/ CBC has a density of 2.30 g/cm
3 , bending strength of 112 MPa, and thermal conductivity of 170 W/mK. The obtained AlN-AlN/ CBC plates showed a high strength as a result of the direct AlN-AlN sintering at the AlN and AlN/ CBC interface. [ABSTRACT FROM AUTHOR]- Published
- 2012
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7. SiC Ceramic-Bonded Carbon Fabricated With Si3N4 and Carbon Powders.
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Chen, Weiwu, Tojo, Tetsuro, and Miyamoto, Yoshinari
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CERAMICS ,SINTERING ,TEMPERATURE ,THERMAL conductivity ,BENDING (Metalwork) ,CARBON ,SILICON carbide ,POWDERS - Abstract
New composites called ceramic-bonded carbon ( CBCs), consisting of a three-dimensional structure of carbon particles bonded with thin ceramic boundaries, were developed. To fabricate light and tough CBCs and to understand their reinforcing mechanism, Si
3 N4 and carbon powders (25:75 in volume ratio) were gelcasted and then sintered by spark plasma sintering at temperatures of 1700-1900°C. The ceramic boundary of SiC was formed in situ at above 1700°C by the reaction of Si3 N4 and C. The sintered CBCs showed a unique microstructure consisting of carbon particles and ceramic boundaries of 15 μm in size and 0.5-3 μm in thickness, respectively. With an increase in sintering temperature, physical bonding of ceramic grains to the carbon particles was enhanced as the grain growth of SiC increased. The SiC/ CBCs sintered at 1900°C were highly dense (97% theoretical density), lightweight (2.36 mg/m3 ), and had both relatively high bending strength and thermal conductivity (135 MPa and 140 W/mK, respectively). [ABSTRACT FROM AUTHOR]- Published
- 2012
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8. Identification of a quantitative trait locus for spontaneous osteoarthritis in STR/ort mice.
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Watanabe, Ken, Oue, Yasuhiro, Miyamoto, Yoshinari, Matsuura, Makiko, Mizuno, Yusuke, and Ikegawa, Shiro
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OSTEOARTHRITIS ,GENETICS ,LABORATORY mice ,CARTILAGE ,SCANNING electron microscopy ,GENOMES - Abstract
Osteoarthritis (OA) is the most common joint disorder in humans. Most of the animal models of OA were developed by surgical destabilization of joints or through transgenic approaches, and information from naturally occurring models of OA is very limited. The mouse strain STR/ort is recognized as a spontaneous model of OA. This mouse is unique in that it develops late onset cartilage degeneration of the tibio-femoral joint, similar to human OA. The purpose of this study was to identify quantitative trait loci (QTL) for the OA phenotype in STR/ort. Whereas the trait had been reported to be recessive, a significant population of the F1 generation exhibited OA phenotype. Thus, backcrossed (BC) mice generated by crossing F1 male to C57BL/6N female mice were used for genetic analysis. Degeneration of articular cartilage in BC mice was evaluated by scanning electron microscopy. Linkage analysis was carried out using microsatellite markers covering the entire genome. Cartilage degeneration in STR/ort mice was a polygenic trait. A QTL for the OA phenotype was mapped to a region 20 centimorgans proximal to the centromere of chromosome 4 (LOD = 3.37, p = 0.0065). A QTL associated with the onset of cartilage degeneration in C57BL/6N mice was also identified on chromosome 5 (LOD = 3.04, p = 0.0147). These results suggest that multiple loci are involved in the OA phenotype in mice. © 2011 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 30:15-20, 2012 [ABSTRACT FROM AUTHOR]
- Published
- 2012
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9. αvβ5 Integrin promotes dedifferentiation of monolayer-cultured articular chondrocytes.
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Fukui, Naoshi, Ikeda, Yasuko, Tanaka, Nobuho, Wake, Masahiro, Yamaguchi, Tetsuo, Mitomi, Hiroyuki, Ishida, Satoru, Furukawa, Hiroshi, Hamada, Yoshiki, Miyamoto, Yoshinari, Sawabe, Motoji, Tashiro, Toshiyuki, Katsuragawa, Yozo, and Tohma, Shigeto
- Abstract
Objective When cultured in monolayers, articular chondrocytes undergo an obvious phenotypic change. Although the involvement of integrins has been suggested, the exact mechanisms of the change have not been determined. This study was undertaken to clarify the mechanisms underlying the loss of chondrocyte phenotype early after plating. Methods Primary cultured human articular chondrocytes were used for the experiments. Involvement of respective integrins in the phenotypic change was investigated in RNA interference (RNAi) experiments. A signaling pathway involved in the change was identified in experiments using specific inhibitors and adenoviruses encoding mutated genes involved in the pathway. Adenoviruses carrying mutated GTPases were used to determine the involvement of small GTPases in the process. Results In monolayer-cultured chondrocytes, suppression of αv or β5 integrin expression by RNAi inhibited morphologic changes in the cells and increased (or prevented a reduction in) the expression of various cartilage matrix genes. Consistent results were obtained in experiments using a blocking antibody and a synthetic inhibitor of αvβ5 integrin. The decrease in cartilage matrix gene expression in chondrocytes after plating was mediated by ERK signaling, which was promoted primarily by αvβ5 integrin. In articular chondrocytes, the affinity of αvβ5 integrin for ligands was regulated by the small GTPase R-Ras. R-Ras was gradually activated in monolayer-cultured chondrocytes after plating, which caused a gradual decline in cartilage matrix gene expression through enhanced αvβ5 integrin activation and the subsequent increase in ERK signaling. Conclusion Our findings indicate that αvβ5 integrin may be involved in the change that occurs in monolayer-cultured chondrocytes after plating. [ABSTRACT FROM AUTHOR]
- Published
- 2011
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10. αvβ5 Integrin promotes dedifferentiation of monolayer-cultured articular chondrocytes.
- Author
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Fukui, Naoshi, Ikeda, Yasuko, Tanaka, Nobuho, Wake, Masahiro, Yamaguchi, Tetsuo, Mitomi, Hiroyuki, Ishida, Satoru, Furukawa, Hiroshi, Hamada, Yoshiki, Miyamoto, Yoshinari, Sawabe, Motoji, Tashiro, Toshiyuki, Katsuragawa, Yozo, and Tohma, Shigeto
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CARTILAGE physiology ,ANALYSIS of variance ,BIOPHYSICS ,FISHER exact test ,RESEARCH methodology ,OSTEOARTHRITIS ,RESEARCH funding ,T-test (Statistics) ,WESTERN immunoblotting ,EQUIPMENT & supplies - Abstract
Objective When cultured in monolayers, articular chondrocytes undergo an obvious phenotypic change. Although the involvement of integrins has been suggested, the exact mechanisms of the change have not been determined. This study was undertaken to clarify the mechanisms underlying the loss of chondrocyte phenotype early after plating. Methods Primary cultured human articular chondrocytes were used for the experiments. Involvement of respective integrins in the phenotypic change was investigated in RNA interference (RNAi) experiments. A signaling pathway involved in the change was identified in experiments using specific inhibitors and adenoviruses encoding mutated genes involved in the pathway. Adenoviruses carrying mutated GTPases were used to determine the involvement of small GTPases in the process. Results In monolayer-cultured chondrocytes, suppression of αv or β5 integrin expression by RNAi inhibited morphologic changes in the cells and increased (or prevented a reduction in) the expression of various cartilage matrix genes. Consistent results were obtained in experiments using a blocking antibody and a synthetic inhibitor of αvβ5 integrin. The decrease in cartilage matrix gene expression in chondrocytes after plating was mediated by ERK signaling, which was promoted primarily by αvβ5 integrin. In articular chondrocytes, the affinity of αvβ5 integrin for ligands was regulated by the small GTPase R-Ras. R-Ras was gradually activated in monolayer-cultured chondrocytes after plating, which caused a gradual decline in cartilage matrix gene expression through enhanced αvβ5 integrin activation and the subsequent increase in ERK signaling. Conclusion Our findings indicate that αvβ5 integrin may be involved in the change that occurs in monolayer-cultured chondrocytes after plating. [ABSTRACT FROM AUTHOR]
- Published
- 2011
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11. Cloning and characterization of the osteoarthritis-associated gene DVWA.
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Nakajima, Masahiro, Miyamoto, Yoshinari, and Ikegawa, Shiro
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OSTEOARTHRITIS ,ARTICULAR cartilage ,CLONING ,HUMAN chromosomes ,ARTHRITIS ,PROTEIN metabolism ,AMINO acids ,ANIMAL experimentation ,ANIMALS ,BIOCHEMISTRY ,BIOLOGICAL transport ,CARTILAGE cells ,CELL lines ,COLLAGEN ,DOCUMENTATION ,EXTRACELLULAR space ,GENES ,GENETIC techniques ,HUMAN genome ,IMMUNITY ,PHENOMENOLOGY ,MICE ,PROTEINS ,RNA ,GENE expression profiling ,METABOLISM - Abstract
Osteoarthritis (OA) is one of the most prevalent skeletal diseases. Recently, we identified a novel gene on chromosome 3p24.3, named DVWA (double von Willebrand factor A domains), and its functional variants, which are associated with susceptibility to knee OA. Here we report the cloning and characterization of the DVWA gene. DVWA consisted of seven exons and had four alternative splicing variants, which encoded long (385 amino acid) and short (276 amino acid) proteins (L-DVWA and S-DVWA, respectively). S-DVWA was an N-terminal truncated form of L-DVWA and lacked a signal peptide and a part of a VWA domain. L-DVWA and S-DVWA transcripts were mainly expressed in articular cartilage. Immunoblot analysis using epitope-tagged proteins showed L-DVWA in the conditioned media and S-DVWA only in the cell, consistent with the in silico prediction. We also cloned the murine counterpart of DVWA, which was found to be identical to Col6a4, which has recently been reported. L-DVWA had 73% identity to the N-terminal sequence of the 2,309-amino acid Col6a4 protein. The mouse Dvwa/Col6a4 mRNA was present mainly in the small intestine in embryos and adults, but not in cartilage. The amino acid sequence of L-DVWA was conserved in higher species than chicken, but that of S-DVWA was unique in human. Knockdown of DVWA by siRNAs increased expression of chondrocyte matrix genes. Our study indicates that DVWA is evolutionally very unique, which, together with its specific expression in articular cartilage, suggests its specific role in human cartilage metabolism. [ABSTRACT FROM AUTHOR]
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- 2011
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12. STRATEGIC INVESTMENT IN A LABOUR-MANAGED DUOPOLY.
- Author
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Miyamoto, Yoshinari
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DUOPOLIES ,BUSINESS models ,LABOR-management committees ,CAPITAL investments ,LABOR economics ,ECONOMIC equilibrium ,INDUSTRIAL relations ,PRODUCTION (Economic theory) - Abstract
Developing a Cournot two-stage game model with strategic capital interaction, we compare two different kinds of equilibrium in a labour-managed (LM) duopoly. An LM firm's reaction function is negatively sloped when capital and output are simultaneously determined, while the slope of its reaction function in the second stage changes in sign depending on the magnitude of its labour-expansion elasticity. Hence, whether the LM firms employ more capital and produce greater output at the equilibria in the two-stage game model than at the equilibria resulting from the simultaneous selection of capital and output depends on the magnitude of their labour-expansion elasticity. [ABSTRACT FROM AUTHOR]
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- 2010
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13. SNPs in BRAP associated with risk of myocardial infarction in Asian populations.
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Ozaki, Kouichi, Sato, Hiroshi, Inoue, Katsumi, Tsunoda, Tatsuhiko, Sakata, Yasuhiko, Mizuno, Hiroya, Tsung-Hsien Lin, Miyamoto, Yoshinari, Aoki, Asako, Onouchi, Yoshihiro, Sheng-Hsiung Sheu, Ikegawa, Shiro, Odashiro, Keita, Nobuyoshi, Masakiyo, Suh-Hang H Juo, Hori, Masatsugu, Nakamura, Yusuke, and Tanaka, Toshihiro
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MYOCARDIAL infarction ,GENETICS of disease susceptibility ,ATHEROSCLEROSIS ,GENETIC polymorphisms ,ASIANS ,GENETIC research ,DISEASES - Abstract
Myocardial infarction is a common disease and among the leading causes of death in the world. We previously reported association of variants in LGALS2, encoding galectin-2, with myocardial infarction susceptibility in a case-control association study in a Japanese population. Here we identify BRAP (BRCA1-associated protein) as a galectin-2–binding protein. We report an association of SNPs in BRAP with myocardial infarction risk in a large Japanese cohort (P = 3.0 × 10
−18 , OR = 1.48, 2,475 cases and 2,778 controls), with replication in additional Japanese and Taiwanese cohorts (P = 4.4 × 10−6 , 862 cases and 1,113 controls and P = 4.7 × 10−3 , 349 cases and 994 controls, respectively). BRAP expression was observed in smooth muscle cells (SMCs) and macrophages in human atherosclerotic lesions. BRAP knockdown by siRNA using cultured coronary endothelial cells suppressed activation of NF-κB, a central mediator of inflammation. [ABSTRACT FROM AUTHOR]- Published
- 2009
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14. Zonal Gene Expression of Chondrocytes in Osteoarthritic Cartilage.
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Fukui, Naoshi, Miyamoto, Yoshinari, Nakajima, Masahiro, Ikeda, Yasuko, Hikita, Atsuhiko, Furukawa, Hiroshi, Mitomi, Hiroyuki, Tanaka, Nobuho, Katsuragawa, Yozo, Yamamoto, Seizo, Sawabe, Motoji, Juji, Takuo, Mori, Toshihito, Suzuki, Ryuji, and Ikegawa, Shiro
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CARTILAGE cells ,GENE expression ,OSTEOARTHRITIS ,PROTEIN microarrays ,METABOLISM - Abstract
The article discusses a study which determined the chondrocyte metabolism in osteoarthritic cartilage. The cartilage was divided into three zones and gene expression profiles were determined by custom-designed microarray focused on chondrocyte-related genes. The metabolic activity of chondrocytes differed among zones.
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- 2008
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15. FREEFORM FABRICATION OF ALUMINA DENTAL-CROWN MODELS BY USING STEREOLITHOGRAPHY.
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Ishikawa, Masahito, Kirihara, Soshu, Miyamoto, Yoshinari, and Sohmura, Taiji
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RAPID prototyping ,ALUMINUM oxide ,DENTAL crowns ,BIOCERAMICS ,DENTAL ceramics ,DENTAL fillings - Abstract
The article discusses a study which described a technique that may be used in the freeform fabrication of alumina dental-crown models through stereolithography. Due to their desirable aesthetics and biocompatibility, ceramic materials have been popular in the area of dental restoration for dentures and crowns. Glass infiltration has been used to improve the flexural strength of sintered specimens used in the study.
- Published
- 2008
16. Common variants in DVWA on chromosome 3p24.3 are associated with susceptibility to knee osteoarthritis.
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Miyamoto, Yoshinari, Dongquan Shi, Nakajima, Masahiro, Ozaki, Kouichi, Sudo, Akihiro, Kotani, Akihiro, Uchida, Atsumasa, Tanaka, Toshihiro, Fukui, Naoshi, Tsunoda, Tatsuhiko, Takahashi, Atsushi, Nakamura, Yusuke, Qing Jiang, and Ikegawa, Shiro
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GENETIC research ,OSTEOARTHRITIS ,CHROMOSOMES ,ETIOLOGY of diseases ,VON Willebrand factor ,PROTEIN binding ,GENETICS - Abstract
Susceptibility to osteoarthritis, the most common human arthritis, is known to be influenced by genetic factors. Through a genome-wide association study using ∼100,000 SNPs, we have identified a previously unknown gene on chromosome 3p24.3, DVWA, which is associated with susceptibility to knee osteoarthritis. Expressed specifically in cartilage, DVWA encodes a 276-amino-acid protein with two regions corresponding to the von Willebrand factor type A domain (VWA domain). Several DVWA SNPs are significantly associated with knee osteoarthritis in two independent Japanese case-control cohorts. This association was replicated in a Japanese population cohort and a Han Chinese case-control cohort (combined P = 7.3 × 10
−11 ). DVWA protein binds to β-tubulin, and the binding is influenced by two highly associated missense SNPs (rs11718863 and rs7639618) located in the VWA domain. The Tyr169-Cys260 isoform of DVWA, which is overrepresented in knee osteoarthritis, showed weaker interaction. Our findings reveal a new paradigm for study of osteoarthritis etiology and pathogenesis. [ABSTRACT FROM AUTHOR]- Published
- 2008
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17. Fabrication and Characterization of Three-Dimensional ZrO2-Toughened Al2O3 Ceramic Microdevices.
- Author
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Chen, Weiwu, Kirihara, Soshu, and Miyamoto, Yoshinari
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SINTERING ,CERAMICS ,DEFORMATIONS (Mechanics) ,HARDNESS ,PROPERTIES of matter - Abstract
Dense three-dimensional (3D) microdevices of ZrO
2 -toughened Al2 O3 (ZTA) were fabricated using microstereolithography and a subsequent sintering process. Using microstereolithography, 3D green bodies could be formed from a 40 vol% ZTA ceramic–resin paste. After sintering, the fabricated 3D devices are converted into dense ceramic devices without deformation. In this study, a gear (with a tooth edge of 25 μm) and a photonic crystal (with a lattice constant of 500 μm) were designed and fabricated. The dimensional accuracy of the fabrication process is within 20 μm and the sintering shrinkage is around 26% for these microdevices. The relative density of the sintered ZTA ceramics reached 96.5% of theoretical value. The measured hardness and toughness were about 14 GPa and 11 MPa m1/2 , respectively, in both the top and side surfaces. A band gap between 320 and 420 GHz was observed in the ZTA photonic crystal. The microstereolithography process can be easily applied to other ceramic materials and devices. [ABSTRACT FROM AUTHOR]- Published
- 2008
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18. Stereolithographic Fabrication and Microwave Properties of 1D Tunable Photonic Crystals Composed of YIG and Alumina Plates in Resin.
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Nakagawa, Takuji, Kageyama, Keisuke, Takagi, Hiroshi, Sakabe, Yukio, Kirihara, Soshu, and Miyamoto, Yoshinari
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CERAMICS ,YTTRIUM iron garnet ,POLYCRYSTALS ,ALUMINUM oxide ,MAGNETIC fields ,ELECTROMAGNETIC waves ,CRYSTALS ,RESONANCE ,FERRITES - Abstract
One-dimensional (1D) photonic crystals composed of a center polycrystalline yttrium iron garnet (YIG) plate sandwiched with alternate alumina and resin plates were fabricated using stereolithography. The formed crystals showed a transmission mode of microwave in band gap as a result of resonance at the YIG plate. The transmission frequency and intensity were controlled by applying an external magnetic field. These phenomena can be explained by Faraday and Voigt effects of YIG in magnetic field. The propagation characteristics of microwaves agreed well with the calculated results using the finite element method. [ABSTRACT FROM AUTHOR]
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- 2008
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19. A functional SNP in EDG2 increases susceptibility to knee osteoarthritis in Japanese.
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Mototani, Hideyuki, Iida, Aritoshi, Nakajima, Masahiro, Furuichi, Tatsuya, Miyamoto, Yoshinari, Tsunoda, Tatsuhiko, Sudo, Akihiro, Kotani, Akihiro, Uchida, Atsumasa, Ozaki, Kouichi, Tanaka, Yoshiya, Nakamura, Yusuke, Tanaka, Toshihiro, Notoya, Kohei, and Ikegawa, Shiro
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- 2008
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20. Microfabrication of Three-Dimensional Photonic Crystals of SiO2–Al2O3 Ceramics and Their Terahertz Wave Properties.
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Chen, Weiwu, Kirihara, Soshu, and Miyamoto, Yoshinari
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CRYSTALS ,CERAMICS ,MICROLITHOGRAPHY ,MICROFABRICATION ,TERAHERTZ technology - Abstract
Dense three-dimensional microphotonic crystals of SiO
2 –Al2 O3 ceramics were fabricated using microstereolithography and successive sintering process. The forming dimensional tolerance for a 50 vol% ceramic paste is 10 μm and sintering shrinkage is around 12%. Diamond-type photonic crystals with lattice constants of 500 and 125 μm were formed and sintered successfully. The band gaps of the samples were measured and compared with the theoretically calculated band diagram. [ABSTRACT FROM AUTHOR]- Published
- 2008
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21. Association of the MSX2 gene polymorphisms with ankylosing spondylitis in Japanese.
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Furuichi, Tatsuya, Maeda, Koichi, Chung-Tei Chou, Yu-Fen Liu, Ting-Chun Liu, Miyamoto, Yoshinari, Takahashi, Atsushi, Mori, Kanji, Ikari, Katsunori, Kamatani, Naoyuki, Kurosawa, Hisashi, Inoue, Hisashi, Tsai, Shih-Feng, and Ikegawa, Shiro
- Subjects
GENES ,GENETIC polymorphisms ,ANKYLOSING spondylitis ,PATIENTS ,POPULATION genetics ,MSX genes - Abstract
Several genes have been implicated in the etiology of ankylosing spondylitis (AS); however, the significance of these genes except HLA-B27 remains to be elucidated. In this study, we examined the association of AS with novel candidate genes and previously reported genes other than HLA-B27. We examined a total of 45 single nucleotide polymorphisms (SNPs) in 15 genes by a sequential screening. We first genotyped 170 Japanese AS patients and 896 controls for the SNPs (first screen). Then, we genotyped eight SNPs with P < 0.05 in the first screen for 108 additional Japanese patients (second screen). We checked the replication of the association of the most significant SNP by genotyping 219 Taiwanese AS patients and 185 controls. When the first and second screens were combined, four SNPs showed nominal significance of P < 0.05. An intronic SNP (IVS1 + 996G > A) in MSX2, a novel candidate gene, showed the most significant association ( P = 0.0030). The association was not replicated in our Taiwanese population; however, there was the same trend with the Japanese population in the allelic frequency distribution of the SNP. In the genes previously reported to have association with AS, only one synonymous SNP, c.963T > G in ANKH, showed a marginal association in the Japanese population ( P = 0.045). [ABSTRACT FROM AUTHOR]
- Published
- 2008
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22. Fabrication of Metallodielectric Photonic Crystals with a Diamond Structure and their Microwave Properties.
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Wen Wang, Kirihara, Soshu, Miyamoto, Yoshinari, and Zhihao Jin
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ALLOYS ,METAL crystals ,CRYSTALS ,FIBER optics ,POLYESTERS ,SPECTRUM analysis ,CERAMIC materials ,SOLIDIFICATION ,METALLOGRAPHY - Abstract
Three-dimensional (3D) metallodielectric photonic crystals with a diamond structure were fabricated in order to investigate the formation of stop bands and the absorption ability for microwaves with the dielectric absorbing media embedded into the 3D metal lattice. First, the metallic photonic crystals were prepared by filling the epoxy molds formed by stereolithography with a metal alloy having a low melting point of 70°C, followed by removal of the molds. The metallodielectric photonic crystals were then fabricated by infiltrating the porous metal crystal with a SiC/polyester mixture. The lattice constant of photonic crystals was 15 mm. The effects of different aspect ratios of diamond lattice rods, number of metallic lattice units along Γ-L 〈1 1 1〉, Γ-X 〈1 0 0〉, and Γ-K 〈1 1 0〉 directions, and metallodielectric samples along the Γ-X 〈1 0 0〉 direction on the formation of stop band and microwave absorption ability were investigated in the frequency range from 3 to 30 GHz. Metallodielectric photonic crystals formed showed good absorption ability. The measured transmission spectra of the metallic and metallodielectric crystals agreed well with the simulation of the transmission line modeling method. [ABSTRACT FROM AUTHOR]
- Published
- 2008
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23. Lack of association of single nucleotide polymorphism in LRCH1 with knee osteoarthritis susceptibility.
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Qing Jiang, Dongquan Shi, Nakajima, Masahiro, Jin Dai, Jia Wei, Malizos, Konstantinos N., Jianghui Qin, Miyamoto, Yoshinari, Kamatani, Naoyuki, Baorui Liu, Tsezou, Aspasia, Nakamura, Takahiro, and Ikegawa, Shiro
- Subjects
OSTEOARTHRITIS ,GENETIC polymorphisms ,NUCLEOTIDES ,INTRONS ,KNEE diseases - Abstract
A genetic association of knee osteoarthritis (OA) and a C/T transition single nucleotide polymorphism (SNP) (rs912428) located in intron 1 of the LRCH1 gene has recently been reported in European Caucasians; however, the results are inconsistent. Our objective was to evaluate the association in different knee OA populations. Three case-control association studies were conducted in Han Chinese, Japanese, and Greek Caucasian populations. The LRCH1 SNP was genotyped in patients who had primary symptomatic knee OA with radiographic confirmation and in matched controls, and the association was examined. We performed a meta-analysis for the studies together with results of two previous papers using the DerSimonian–Laird procedure and calculated the power of the pooled studies by the software R. A total of 1,145 OA patients and 1,266 controls were genotyped. No significant difference was detected in genotype or allele frequencies between knee OA and control groups in the three populations (all P > 0.05). Association was not observed even after stratification by gender and Kellgren/Lawrence (K/L) scores. Meta-analysis also supported the lack of association between LRCH1 and knee OA. The strong heterogeneity between original and replication studies was detected in Caucasian populations. However, a tendency for the increase of TT genotype was observed in the European populations (OR = 1.46, P = 0.06). The powers for European and Asian replication studies were less than 0.8. Our results suggest that there is no association between LRCH1 and knee OA. However, lack of association should be concluded by further replication studies. [ABSTRACT FROM AUTHOR]
- Published
- 2008
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24. Growth of Quasi-Aligned AlN Nanofibers by Nitriding Combustion Synthesis.
- Author
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Radwan, Mohamed and Miyamoto, Yoshinari
- Subjects
NANOPARTICLES ,PARTICLES ,NANOCRYSTALS ,NITRIDES ,ALUMINUM compounds ,ALUMINUM nitride - Abstract
Quasi-aligned AlN nanofibers were formed by the nitriding combustion synthesis according to a unique micro-reactor model. A charge composed of aluminum and aluminum nitride diluent powders (40/60 mol%) with a mixture of yttria and ammonium chloride as additives (5 wt% each) was combusted at low nitrogen gas pressures of 0.25 MPa. The FE-SEM images of as-synthesized AlN product showed the formation of ball-like grains (same shape and size as the original Al reactant) that consisted of a thin surface nitride layer or crust cover quasi-aligned AlN nanofibers grown in the interior. The cross-sectional view is sea anemone like. Formation of this novel morphology is believed to occur through a two-stage process. The first one occurs at the preliminary stage of the combustion outside Al particles. After the ignition, the heat generated causes the sublimation and dissociation of ammonium chloride into various gaseous species. This effectively interrupts the combustion and slows down the increase of reaction temperature. In addition, yttria interacts with the native oxide layer present on the surface of Al particles and forms a stable Al–N–Y–O crust. The second stage begins by the infiltration of various gaseous species such as HCl
(g) , NH3(g) , and N2(g) through the crust into the molten Al cores. The “crust–core” systems function as “micro-reactors” where both the nitridation and growth processes occur inside. The molten Al cores are spontaneously halogenated to AlCl3 vapors and the nitridation proceeds by the gas–gas reaction of AlCl3 and NH3 /N2 vapors. The AlN nanofibers are then grown from the vapor phase quasi-aligned inside the micro-reactors by VLS and VS mechanisms. [ABSTRACT FROM AUTHOR]- Published
- 2007
- Full Text
- View/download PDF
25. Meta-analysis of association between the ASPN D-repeat and osteoarthritis.
- Author
-
Nakamura, Takahiro, Shi, Dongquan, Tzetis, Maria, Rodriguez-Lopez, Julio, Miyamoto, Yoshinari, Tsezou, Aspasia, Gonzalez, Antonio, Jiang, Qing, Kamatani, Naoyuki, Loughlin, John, and Ikegawa, Shiro
- Published
- 2007
- Full Text
- View/download PDF
26. Fabrication of carbon nanofiber(CNF)-dispersed Al2O3 composites by pulsed electric-current pressure sintering and their mechanical and electrical properties.
- Author
-
Hirota, Ken, Takaura, Yuichi, Kato, Masaki, and Miyamoto, Yoshinari
- Subjects
CARBON ,ELECTRIC currents ,MICROSTRUCTURE ,IRON metallurgy ,SINTERING - Abstract
Dense Al
2 O3 -based composites (≥99.0% of theoretical) dispersed with carbon nanofibers (CNFs) were fabricated using the pulsed electric-current pressure sintering (PECPS) for 5 min at 1300°C and 30 MPa in a vacuum. The dispersion of CNFs into the matrix depended much on the particle size of the starting Al2 O3 powders. Mechanical properties of the composites were evaluated in relation with their microstructures; high values of three-point bending strength σb (∼800 MPa) and fracture toughness KIC (∼5 MPa·m1/2 ) were attained at the composition of CNF/Al2 O3 = 5:95 vol%, which σb and KIC values were ∼25% and ∼5%, respectively, higher than those of monolithic Al2 O3 . This might be due to the small Al2 O3 grains (1.6 μm) of dense sintered compacts compared with that (4.4 μm) for the pure Al2 O3 ceramics, resulting from the suppression of grain growth during sintering induced by uniformly dispersed CNFs in the matrix. Electrical resistivity of CNF/Al2 O3 composites decreased rapidly from >1015 to ∼2.1 × 10−2 Ωm (5vol%CNF addition), suggesting the machinability of Al2 O3 -based composites by electrical discharge machining. [ABSTRACT FROM AUTHOR]- Published
- 2007
- Full Text
- View/download PDF
27. Fabrication and Measurement of Micro Three-Dimensional Photonic Crystals of SiO2 Ceramic for Terahertz Wave Applications.
- Author
-
Weiwu Chen, Kirihara, Soshu, and Miyamoto, Yoshinari
- Subjects
CERAMICS ,CRYSTALS ,SINTERING ,CAD/CAM systems ,ELECTROMAGNETIC waves ,SPECTRUM analysis - Abstract
Three-dimensional (3D) photonic crystals with a diamond structure made of a dense SiO
2 ceramic were successfully fabricated using a CAD/CAM micro-stereolithography and sintering process. The designed lattice constant of the diamond unit cell was 500 μm and the forming tolerance from 50 vol% SiO2 paste (before sintering) was around 15 μm. After the SiO2 -resin photonic crystals were formed via micro-stereolithography, they were converted to pure SiO2 ceramic photonic crystals of 99% theoretical density by sintering at 1400°C. The electromagnetic wave propagation in these dense SiO2 photonic crystals was measured by terahertz-time-domain spectroscopy. The results showed that the band gap appeared between 470 and 580 GHz in the Γ– X〈100〉 direction, between 490 and 630 GHz in the Γ– K〈110〉 direction, and between 400 and 510 GHz in the Γ– L〈111〉 direction, resulting in the formation of a common band gap in all directions between 490 and 510 GHz. These results agreed well with the band gaps calculated by the plane wave expansion method. [ABSTRACT FROM AUTHOR]- Published
- 2007
- Full Text
- View/download PDF
28. Analysis of Electromagnetic Response of 3-D Dielectric Fractals of Menger Sponge Type.
- Author
-
Semouchkina, Elena, Miyamoto, Yoshinari, Kirihara, Soshu, Semouchkin, George, and Lanagan, Michael
- Subjects
FINITE differences ,NUMERICAL analysis ,DIELECTRICS ,ELECTRICAL engineering materials ,ELECTROMAGNETISM ,FRACTALS - Abstract
Experimental studies and finite-difference time-domain simulations of electromagnetic (EM) response of the second-stage Menger sponge dielectric structures have been performed with different types of excitation in order to gain deeper insight into the phenomenon of EM wave localization in these fractals. Analysis of simulated amplitude distributions of electric field oscillations in the Menger sponges has revealed bandgap-like effects caused by resonances in the front part of the structures, as well as formation of the full-wave resonance mode in the central cavity at the localization frequency. It is demonstrated that penetration of the waves inside the structure at the localization frequency leads to equalizing of the EM response from different parts of the 3-D fractal, however, no high-Q eigenmode is formed in the second-stage Menger sponge. Simulations of the modified fractal structures have been used to show the potential of formation of a bandgap with defect-related localized photon states by 3-D fractals. [ABSTRACT FROM AUTHOR]
- Published
- 2007
- Full Text
- View/download PDF
29. A recurrent mutation in type II collagen gene causes Legg-Calvé-Perthes disease in a Japanese family.
- Author
-
Miyamoto, Yoshinari, Matsuda, Tatsuo, Kitoh, Hiroshi, Haga, Nobuhiko, Ohashi, Hirofumi, Nishimura, Gen, and Ikegawa, Shiro
- Subjects
LEGG-Calve-Perthes disease ,GENETIC mutation ,COLLAGEN diseases ,CONNECTIVE tissue diseases ,HIP joint diseases ,JAPANESE people ,FAMILIAL diseases ,HEALTH - Abstract
Legg-Calvé-Perthes disease (LCPD) is a common childhood hip disorder characterized by sequential stages of involvement of the capital femoral epiphyses, including subchondral fracture, fragmentation, re-ossification and healing with residual deformity. Most cases are sporadic, but familial cases have been described, with some families having multiple affected members. Genetic factors have been implicated in the etiology of LCPD, but the causal gene has not been identified. We have located a missense mutation (p.G1170S) in the type II collagen gene ( COL2A1) in a Japanese family with an autosomal dominant hip disorder manifesting as LCPD and showing considerable intra-familial phenotypic variation. This is the first report of a mutation in hereditary LCPD. COL2A1 mutations may be more common in LCPD patients than currently thought, particularly in familial and/or bilateral cases. [ABSTRACT FROM AUTHOR]
- Published
- 2007
- Full Text
- View/download PDF
30. A functional polymorphism in the 5′ UTR of GDF5 is associated with susceptibility to osteoarthritis.
- Author
-
Miyamoto, Yoshinari, Mabuchi, Akihiko, Shi, Dongquan, Kubo, Toshikazu, Takatori, Yoshio, Saito, Susumu, Fujioka, Mikihiro, Sudo, Akihiro, Uchida, Atsumasa, Yamamoto, Seizo, Ozaki, Koichi, Takigawa, Masaharu, Tanaka, Toshihiro, Nakamura, Yusuke, Jiang, Qing, and Ikegawa, Shiro
- Subjects
OSTEOARTHRITIS ,ARTICULAR cartilage diseases ,DISEASES in older people ,GROWTH factors ,GENETIC polymorphisms ,JAPANESE people ,DISEASES - Abstract
Osteoarthritis (MIM 165720), characterized by degeneration of articular cartilage, is the most common form of human arthritis and a major concern for aging societies worldwide. Epidemiological and genetic studies have shown that osteoarthritis is a polygenic disease. Here, we report that the gene encoding growth differentiation factor 5 (GDF5) is associated with osteoarthritis in Asian populations. A SNP in the 5′ UTR of GDF5 (+104T/C; rs143383) showed significant association (P = 1.8 × 10
−13 ) with hip osteoarthritis in two independent Japanese populations. This association was replicated for knee osteoarthritis in Japanese (P = 0.0021) and Han Chinese (P = 0.00028) populations. This SNP, located in the GDF5 core promoter, exerts allelic differences on transcriptional activity in chondrogenic cells, with the susceptibility allele showing reduced activity. Our findings implicate GDF5 as a susceptibility gene for osteoarthritis and suggest that decreased GDF5 expression is involved in the pathogenesis of osteoarthritis. [ABSTRACT FROM AUTHOR]- Published
- 2007
- Full Text
- View/download PDF
31. Fabrication and Microwave Properties of Three-Dimensional Photonic Crystals With a Diamond Structure Composed of Ceramic Spheres in Resin.
- Author
-
Nakagawa, Takuji, Kageyama, Keisuke, Wada, Nobuyuki, Sakabe, Yukio, Kirihara, Soshu, and Miyamoto, Yoshinari
- Subjects
CRYSTALS ,CERAMICS ,MICROWAVES ,LITHOGRAPHY ,DIELECTRICS ,ELECTROMAGNETIC waves - Abstract
Three-dimensional photonic crystals with a diamond structure composed of YSZ (3 mol% Y
2 O3 -stabilized ZrO2 ) spheres in a resin matrix were fabricated by using stereolithography. The lattice constant was 12 mm and the diameter of the spheres was 5 mm. These photonic crystals made of ceramic spheres showed complete photonic band gaps at around 12 GHz between the eighth and ninth bands. The propagation characteristics of microwaves agreed well with the calculated results using the plane wave expansion method. [ABSTRACT FROM AUTHOR]- Published
- 2007
- Full Text
- View/download PDF
32. A functional SNP in ITIH3 is associated with susceptibility to myocardial infarction.
- Author
-
Ebana, Yusuke, Ozaki, Kouichi, Inoue, Katsumi, Sato, Hiroshi, Iida, Aritoshi, Lwin, Htay, Saito, Susumu, Mizuno, Hiroya, Takahashi, Atsushi, Nakamura, Takahiro, Miyamoto, Yoshinari, Ikegawa, Shiro, Odashiro, Keita, Nobuyoshi, Masakiyo, Kamatani, Naoyuki, Hori, Masatsugu, Isobe, Mitsuaki, Nakamura, Yusuke, and Tanaka, Toshihiro
- Subjects
MYOCARDIAL infarction ,CORONARY disease ,GENETIC polymorphisms ,DISEASE risk factors ,GLOBULINS ,PROTEINS - Abstract
Myocardial infarction (MI) results from complex interactions of multiple genetic and environmental factors. To disclose genetic backgrounds of MI, we performed a large-scale, case-control association study using 52,608 gene-based single-nucleotide polymorphism (SNP) markers, and identified a candidate SNP located on chromosome 3p21.2–p21.1. Subsequent linkage–disequilibrium mapping indicated very significant association between MI and a SNP in exon 2 of the inter-alpha (globulin) inhibitor 3 gene ( ITIH3; χ
2 = 24.88, P = 6.1 × 10−7 , 3,353 affected individuals versus 3,807 controls). In vitro functional analyses showed that this SNP enhanced the transcriptional level of the ITIH3 gene. Furthermore, we found expression of the ITIH3 protein in the vascular smooth muscle cells and macrophages in the human atherosclerotic lesions, suggesting ITIH3 SNP to be a novel genetic risk factor of MI. [ABSTRACT FROM AUTHOR]- Published
- 2007
- Full Text
- View/download PDF
33. Fabrication of Three-Dimensional Micro Photonic Crystals of Resin-Incorporating TiO2 Particles and their Terahertz Wave Properties.
- Author
-
Chen, Weiwu, Kirihara, Soshu, and Miyamoto, Yoshinari
- Subjects
PHOTONICS ,THREE-dimensional imaging ,TERAHERTZ technology ,DIELECTRIC measurements ,TITANIUM dioxide ,CRYSTAL models ,EXPANSION of solids - Abstract
Three-dimensional (3D) photonic crystals with a diamond structure made from 40 vol% TiO
2 –acrylate dielectric composites were formed by means of a CAD/CAM micro-stereolithography system. The lattice constant of the diamond unit cell was 500 μm and the forming accuracy was 10 μm. The photonic band gap in the Γ–X 〈100〉 direction measured by terahertz-time-domain spectroscopy appeared at 280–360 GHz, which agreed fairly well with the band gap calculated by the plane wave expansion method. [ABSTRACT FROM AUTHOR]- Published
- 2007
- Full Text
- View/download PDF
34. Identification of a novel non-coding RNA, MIAT, that confers risk of myocardial infarction.
- Author
-
Ishii, Nobuaki, Ozaki, Kouichi, Sato, Hiroshi, Mizuno, Hiroya, Susumu Saito, Takahashi, Atsushi, Miyamoto, Yoshinari, Ikegawa, Shiro, Kamatani, Naoyuki, Hori, Masatsugu, Satoshi Saito, Nakamura, Yusuke, and Tanaka, Toshihiro
- Subjects
MYOCARDIAL infarction ,GENETIC polymorphisms ,CARDIOGENIC shock ,RNA ,HEART diseases ,GENETIC disorders - Abstract
Through a large-scale case-control association study using 52,608 haplotype-based single nucleotide polymorphism (SNP) markers, we identified a susceptible locus for myocardial infarction (MI) on chromosome 22q12.1. Following linkage disequilibrium (LD) mapping, haplotype analyses revealed that six SNPs in this locus, all of which were in complete LD, showed markedly significant association with MI ( χ
2 =25.27, P=0.0000005; comparison of allele frequency, 3,435 affected individuals versus 3,774 controls, in the case of intron 1 5,338 C>T; rs2331291). Within this locus, we isolated a complete cDNA of a novel gene, designated myocardial infarction associated transcript ( MIAT). MIAT has five exons, and in vitro translation assay showed that MIAT did not encode any translational product, indicating that this is likely to be a functional RNA. In vitro functional analyses revealed that the minor variant of one SNP in exon 5 increased transcriptional level of the novel gene. Moreover, unidentified nuclear protein(s) bound more intensely to risk allele than non-risk allele. These results indicate that the altered expression of MIAT by the SNP may play some role in the pathogenesis of MI. [ABSTRACT FROM AUTHOR]- Published
- 2006
- Full Text
- View/download PDF
35. A functional SNP in PSMA6 confers risk of myocardial infarction in the Japanese population.
- Author
-
Ozaki, Kouichi, Sato, Hiroshi, Iida, Aritoshi, Mizuno, Hiroya, Nakamura, Takahiro, Miyamoto, Yoshinari, Takahashi, Atsushi, Tsunoda, Tatsuhiko, Ikegawa, Shiro, Kamatani, Naoyuki, Hori, Masatsugu, Nakamura, Yusuke, and Tanaka, Toshihiro
- Subjects
MYOCARDIAL infarction ,CORONARY disease ,HEART diseases ,CARDIOVASCULAR diseases ,GENETICS ,BIOLOGY - Abstract
Inflammation is now considered critical in the pathogenesis of myocardial infarction. One of the mechanisms regulating the inflammatory process is the ubiquitin-proteasome system. We investigated whether variants of the 20S proteasome are associated with susceptibility to myocardial infarction and found a common SNP (minor allele frequency of 0.35) in the proteasome subunit α type 6 gene (PSMA6) conferring risk of myocardial infarction in the Japanese population (χ
2 = 21.1, P = 0.0000044, 2,592 affected individuals versus 2,851 controls). We replicated this association in another panel of myocardial infarction and control subjects, although its relevance to other ethnic groups remains to be clarified. The SNP, located in the 5′ untranslated region of exon 1 in this gene, enhanced the transcription of PSMA6. Moreover, suppression of PSMA6 expression using short interfering RNA in cultured cells reduced activation of the transcription factor NF-κB by stabilizing phosphorylated IκB. Our results implicate this PSMA6 SNP as a previously unknown genetic risk factor for myocardial infarction. [ABSTRACT FROM AUTHOR]- Published
- 2006
- Full Text
- View/download PDF
36. Microwave Absorption in Photonic Crystals Composed of SiC/Resin with a Diamond Structure.
- Author
-
Zhaoting Liu, Kirihara, Soshu, Miyamoto, Yoshinari, and Di Zhang
- Subjects
CRYSTALS ,ELECTRIC equipment ,SYNTHETIC gums & resins ,INDUSTRIAL chemistry ,CERAMICS - Abstract
Three-dimensional photonic crystals were fabricated by infiltrating an epoxy mold with a SiC/polyester mixture. The epoxy molds with normal or inverse diamond structures were formed by stereolithography. The size of the mold was 45 mm × 18 mm × 18mm, and the lattice constant of the photonic crystals was 18 mm. The effects of the epoxy mold type, aspect ratio (the ratio of height and diameter of a diamond lattice rod), and number of sample units on the formation of photonic band gap (PBG) and microwave absorption ability along the 〈100〉 direction were studied. The attenuations of microwave transmission and reflection were measured through the photonic crystal samples at a frequency range of 3–12 GHz with a network analyzer. The results obtained suggest that the combination of the absorbing material SiC and diamond structure has a dual effect to form a PBG with a high absorption ability. [ABSTRACT FROM AUTHOR]
- Published
- 2006
- Full Text
- View/download PDF
37. A type II collagen mutation also results in oto-spondylo-megaepiphyseal dysplasia.
- Author
-
Miyamoto, Yoshinari, Nakashima, Eiji, Hiraoka, Hisatada, Ohashi, Hirofumi, and Ikegawa, Shiro
- Subjects
DYSPLASIA ,COLLAGEN ,DEAFNESS ,EXONS (Genetics) ,GENETIC mutation ,HUMAN genetics - Abstract
Oto-spondylo-megaepiphyseal dysplasia (OSMED) is a skeletal dysplasia characterized by severe sensorineural hearing loss, enlarged epiphyses and early onset of osteoarthritis. COL11A2 has been reported as a causative gene for OSMED. We have identified a novel COL2A1 mutation at a splice-acceptor site within intron 10 (c.709–2A>G) in an OSMED patient. This mutation caused the skipping of exon 11, and of exons 11 and 13. These exon-skipping events are presumed to cause an in-frame deletion of the triple helical region of the COL2A1 product. Thus, our findings highlight the genetic heterogeneity of OSMED and extend the phenotypic spectrum of type II collagenopathy, as well as confirming the overlap between type II and type XI collagenopathies. [ABSTRACT FROM AUTHOR]
- Published
- 2005
- Full Text
- View/download PDF
38. MATN and LAPTM Are Parts of Larger Transcription Units Produced by Intergenic Splicing: Intergenic Splicing May Be a Common Phenomenon.
- Author
-
Maeda, Koichi, Horikoshi, Taizo, Nakashima, Eiji, Miyamoto, Yoshinari, Mabuchi, Akihiko, and Ikegawa, Shiro
- Abstract
Intergenic splicing, the joining of exons from separate genes, has been observed only rarely in mammals. While the matrilin (MATN) and lysosomal-associated protein transmembrane (LAPTM) genes comprise distinct gene families, we have demonstrated intergenic splicing between two sets of family genes, the matrilin-3 (MATN3) and lysosomal-associated protein transmembrane 4α (LAPTM4A), and the matrilin-2 (MATN2) and lysosomal-associated protein transmembrane 4β (LAPTM4B). The expression pattern and sub-cellular localization of the MATN–LAPTM hybrid transcripts differ from those of the original genes, suggesting unique functions for the products. Our observations indicate that intergenic splicing is a common and well-regulated phenomenon and underscore the fundamental challenges in defining the gene (transcriptional unit). Given these findings, the number of gene in the human genome may be smaller than present estimates suggest. [ABSTRACT FROM PUBLISHER]
- Published
- 2005
39. Fabrication of Photonic Crystal with a Diamond Structure Having an Air Cavity Defect and its Microwave Properties.
- Author
-
Kanehira, Shingo, Kirihara, Soshu, Miyamoto, Yoshinari, Sakoda, Kazuaki, and Takeda, Mitsuo Wada
- Subjects
CRYSTALS ,CERAMICS ,PARTICLES ,ELECTROMAGNETIC waves ,MICROWAVES ,INDUSTRIAL chemistry - Abstract
Three-dimensional photonic crystals with a diamond lattice structure consisting of 5 × 5 × 5 unit cells with the unit cell dimension of 15 mm were fabricated using TiO
2 -based ceramic particles dispersed epoxy by stereolithography. The diamond lattice showed a perfect band gap between 14.3 and 15.8 GHz. An air cavity defect with a rectangular shape (15 mm × 45 mm × 15 mm) was introduced at the center of the crystal by extracting 3 unit cells in order to investigate the shape effect of the defect on the formation of localized defect modes of electromagnetic wave. When microwaves were radiated normal to the wide sides (45 mm × 15 mm) of the rectangular shape defect, a sharp localized mode appeared at the middle of the band gap. However, no localized mode was observed for incident waves normal to the smaller side (15 mm × 15 mm) because of the symmetry mismatching between internal eigenmodes in the defect cavity and incident plane waves. The mode analysis using a simple cavity model showed the penetration of the electric field of resonant modes about 2.4 mm into the host lattice. [ABSTRACT FROM AUTHOR]- Published
- 2005
- Full Text
- View/download PDF
40. A functional SNP in CILP, encoding cartilage intermediate layer protein, is associated with susceptibility to lumbar disc disease.
- Author
-
Seki, Shoji, Kawaguchi, Yoshiharu, Chiba, Kazuhiro, Mikami, Yasuo, Kizawa, Hideki, Oya, Takeshi, Mio, Futoshi, Mori, Masaki, Miyamoto, Yoshinari, Masuda, Ikuko, Tsunoda, Tatsuhiko, Kamata, Michihiro, Kubo, Toshikazu, Toyama, Yoshiaki, Kimura, Tomoatsu, Nakamura, Yusuke, and Ikegawa, Shiro
- Subjects
EUGENICS ,LIGAMENTS ,EXTRACELLULAR matrix proteins ,AMINO acids ,EXTRACELLULAR matrix ,MUSCULOSKELETAL system - Abstract
Lumbar disc disease (LDD) is caused by degeneration of intervertebral discs of the lumbar spine. One of the most common musculoskeletal disorders, LDD has strong genetic determinants. Using a case-control association study, we identified a functional SNP (1184T?C, resulting in the amino acid substitution I395T) in CILP, which encodes the cartilage intermediate layer protein, that acts as a modulator of LDD susceptibility. CILP was expressed abundantly in intervertebral discs, and its expression increased as disc degeneration progressed. CILP colocalized with TGF-ß1 in clustering chondrocytes and their territorial matrices in intervertebral discs. CILP inhibited TGF-ß1-mediated induction of cartilage matrix genes through direct interaction with TGF-ß1 and inhibition of TGF-ß1 signaling. The susceptibility-associated 1184C allele showed increased binding and inhibition of TGF-ß1. Therefore, we conclude that the extracellular matrix protein CILP regulates TGF-ßsignaling and that this regulation has a crucial role in the etiology and pathogenesis of LDD. Our study also adds to the list of connective tissue diseases that are associated with TGF-ß. [ABSTRACT FROM AUTHOR]
- Published
- 2005
- Full Text
- View/download PDF
41. Fabrication of TiO2–SiO2 Photonic Crystals with Diamond Structure.
- Author
-
Kanehira, Shingo, Kirihara, Soshu, and Miyamoto, Yoshinari
- Subjects
CERAMICS ,CRYSTALS ,LITHOGRAPHY ,EPOXY resins ,SINTERING ,CHEMICAL molding ,PHOTONICS - Abstract
Ceramic photonic crystals with diamond structure were fabricated using stereolithography and successive sintering. The green body of an epoxy resin incorporating 10 vol% TiO
2 –SiO2 was formed by stereolithography and then heated in air at 1100°–1400°C for 2 h. The sintered products maintained the diamond structure with a linear shrinkage ratio of about 57% and a porosity of 38%. The ceramic photonic crystal with eight unit cells showed a photonic band gap at the center frequency of 23.5 GHz. This fabrication method of three-dimensional (3D) ceramic photonic crystals is applicable to other 3D structural ceramics and does not require any molding techniques. [ABSTRACT FROM AUTHOR]- Published
- 2005
- Full Text
- View/download PDF
42. Growth Mechanism of Nanometer-Sized SiC and Oxidation Resistance of SiC-Coated Diamond Particles.
- Author
-
Morisada, Yoshiaki, Miyamoto, Yoshinari, Moriguchi, Hideki, Tsuduki, Katsunori, and Ikegaya, Akihiko
- Subjects
COATING processes ,SILICON carbide ,CHEMICAL reactions ,DIAMONDS ,MULTILAYERED thin films ,NANOPARTICLES ,ACTIVATION (Chemistry) ,VAPOR-plating - Abstract
Diamond particles were coated with a thin SiC layer by the reaction of SiO vapor with diamond, and the growth mechanism of SiC as well as the oxidation resistance of the SiC coated diamond were studied. The growth process of the SiC layer can be separated into two steps. In the first step, a thin layer of SiC with a thickness of about 15 nm is formed due to the reaction between SiO vapor and diamond. In the second step, nanometer-sized SiC granules are deposited on the SiC layer by the reaction between SiO vapor and CO. The apparent activation energy for the formation of SiC layer on diamond was found to be 100 k J/mol. This value suggests that the SiC coating process occurred mainly by vapor-phase reaction. The oxidation resistance of the SiC-coated diamond was improved depending on the thickness of the SiC layer. Oxidation of the SiC-coated diamond particles began at 950°C, which was 400°C higher than that of uncoated diamond. [ABSTRACT FROM AUTHOR]
- Published
- 2004
- Full Text
- View/download PDF
43. Oxidation Resistance of Multiwalled Carbon Nanotubes Coated with Silicon Carbide.
- Author
-
Morisada, Yoshiaki, Maeda, Masakatsu, Shibayanagi, Toshiya, and Miyamoto, Yoshinari
- Subjects
NANOTUBES ,CARBON ,SILICON carbide ,SILICON compounds ,OXIDATION ,CHEMICAL reactions - Abstract
Multiwalled carbon nanotubes (MWCNTs) were coated with a SiC layer using SiO vapor. The growth mechanism of SiC and the oxidation resistance of the SiC-coated MWCNTs were studied. The growth of the SiC layer was controlled by adjusting the partial pressure of CO
2 using carbon felt placed in a crucible. The nanometer-sized SiC particles were deposited onto the tubes by the reaction between SiO(g) and CO(g). On the other hand, the thin surface of the MWCNTs was converted to the SiC layer when the carbon felt was not used. The oxidation durability of MWCNTs was improved by the SiC coating. MWCNTs were oxidized completely in air at 650°C for 60 min. However, about 90 mass% of the SiC-coated MWCNTs remained after the same oxidation test. [ABSTRACT FROM AUTHOR]- Published
- 2004
- Full Text
- View/download PDF
44. Smart Processing Development of Photonic Crystals and Fractals.
- Author
-
Miyamoto, Yoshinari, Kirihara, Soshu, Kanehira, Shingo, Takeda, Mitsuo Wada, Honda, Katsuya, and Sakoda, Kazuaki
- Subjects
TRANSMISSION of electromagnetic waves ,FRACTALS ,CRYSTALLOGRAPHY ,CRYSTALS ,POWDERS ,ELECTROMAGNETIC theory ,ELECTROMAGNETIC waves ,CONSTRUCTION materials - Abstract
A new concept of smart processing is proposed that can produce advanced materials and components by finely controlling processing energy and engineering structures. New functional components of 3D photonic crystals and fractals are demonstrated, which are constructed of dielectric ceramics and a polymer using a CAD/CAM stereolithography system. By modifying the structure of diamond-like photonic crystals using free-form fabrication, electromagnetic waves can be controlled, opening the way for new applications in communication and sensing technology. The photonic fractal, a new material that can strongly localize electromagnetic waves without reflection and transmission, will also lead to new applications in the energy and medical fields. [ABSTRACT FROM AUTHOR]
- Published
- 2004
- Full Text
- View/download PDF
45. Electromagnetic wave control of ceramic/resin photonic crystals with diamond structure
- Author
-
Kirihara, Soshu, Takeda, Mitsuo, Sakoda, Kazuaki, and Miyamoto, Yoshinari
- Subjects
CRYSTALS ,PHOTONICS ,DIAMONDS ,CERAMICS ,COMPOSITE materials ,DIELECTRICS - Abstract
Millimeter-order photonic crystals with the periodic arrangement of the dielectric constant were fabricated by infiltrating the mixed slurry of ceramics and polyester into the epoxy molds with an inverse form of a diamond structure. The epoxy molds are designed and processed by using a CAD/CAM process of stereolithography. The photonic crystals were prepared to have the diamond structure of the ceramic/polyester composite lattice, which is embedded in the epoxy matrix. The ceramic powders mixed with polyester are TiO
2 , SrTiO3 , and BaTiO3 with high dielectric constant. It is possible to control more freely and widely the dielectric constant of the photonic crystals by this method. These ceramic/resin photonic crystals formed the complete photonic band gaps in the microwave band of 7–11 GHz, which can totally reflect the electromagnetic wave for all crystal directions. Attenuation profiles of the transmission amplitude in the band gaps were controlled with the dielectric constant of the composite lattice. The obtained results fairly agreed with the theoretical simulation of the electromagnetic wave propagation through photonic crystals. [Copyright &y& Elsevier]- Published
- 2004
- Full Text
- View/download PDF
46. Band Gap Modification of Diamond Photonic Crystals by Changing the Volume Fraction of the Dielectric Lattice.
- Author
-
Kanehira, Shingo, Kirihara, Soshu, Miyamoto, Yoshinari, Sakoda, Kazuaki, and Takeda, Mitsuo Wada
- Subjects
CRYSTALS ,PHOTONICS ,DIELECTRICS - Abstract
Photonic crystals with a diamond structure of epoxy lattices in which TiO[sub 2]-based ceramic particles are dispersed were fabricated by stereolithography. The periodicity of the lattice was designed to reflect electromagnetic waves in the gigahertz range. The volume fraction (β) of the dielectric lattice medium was modified from 14% to 33% by changing the rod diameter of the lattice. The photonic band gap was observed along Γ-L 〈111〉, Γ-X 〈100〉, and Γ-K 〈110〉 directions and the complete photonic band gap was formed at over β = 20%. The width of the forbidden gap increased gradually when the β increased over 14%, and reached 2.4 GHz at β = 33%. These results agreed with the band calculation using the plane wave expansion method. [ABSTRACT FROM AUTHOR]
- Published
- 2003
- Full Text
- View/download PDF
47. Electromagnetic properties of photonic crystals with diamond structure containing defects.
- Author
-
Kanehira, Shingo, Kirihara, Soshu, Miyamoto, Yoshinari, Sakoda, Kazuaki, and Takeda, Mitsuo Wada
- Subjects
PHOTONICS ,CRYSTALS ,ELECTROMAGNETISM ,CRYSTAL defects ,MATERIALS - Abstract
Presents a study which investigated the electromagnetic properties of photonic crystals with diamond structure containing defects. Types of lattice defects in a diamond structure; Calculation of resonant frequencies in the defects; Properties of photonic crystals.
- Published
- 2003
- Full Text
- View/download PDF
48. Fabrication of New Cemented Carbite Containing Diamond Coated with Nanometer-Sized SiC Particles.
- Author
-
Miyamoto, Yoshinari, Kashiwagi, Takehiko, Hirota, Ken, Yamaguchi, Osamu, Moriguchi, Hideki, Tsuduki, Katsunori, and Ikegaya, Akihiko
- Subjects
SILICON carbide ,MICROSTRUCTURE ,SINTERING - Abstract
A simple process for depositing a coating of silicon carbide (SiC) crystallites ∼10 nm in size onto diamond particles has been developed. SiO powders react with diamond in a vacuum at 1350°C to form a uniform β-SiC polycrystalline layer ∼60 nm thick. The SiC coating improves the oxidation resistance of the diamond. A cemented carbide material containing 20vol%-SiC-coated diamond particles was sintered to a relative density of 99.5% by pulsed-electric-current sintering. A Vickers hardness and indentation fracture toughness of 15 GPa and 16.3 MPa·m[sup ½] respectively, were obtained. This toughness is two times higher than that of cemented carbide containing no particles. The higher toughness is attributed to deflection and blockage of crack propagation by the diamond particles. [ABSTRACT FROM AUTHOR]
- Published
- 2003
- Full Text
- View/download PDF
49. One-step sintering of SiGe thermoelectric conversion unit and its electrodes.
- Author
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Lin, Jun-Shan and Miyamoto, Yoshinari
- Published
- 2000
- Full Text
- View/download PDF
50. Solid solubilities of manganese and titanium in aluminum at 0.1 MPa and 2.1 GPa.
- Author
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Minamino, Yoritoshi, Yamane, Toshimi, Araki, Hideki, Takeuchi, Naoya, Kang, Yan-Sheng, Miyamoto, Yoshinari, and Okamoto, Taira
- Published
- 1991
- Full Text
- View/download PDF
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