245 results on '"Yoshiro Suzuki"'
Search Results
52. Similarity law for two-dimensional propagation behavior of ultrasonic wave in concentrically curved fiber CFRP
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Takeshi Ashizawa, Nobuyuki Toyama, Yoshiro Suzuki, Yoshihiro Mizutani, and Akira Todoroki
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Wavefront ,Materials science ,Similarity (geometry) ,Computer simulation ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Governing equation ,020303 mechanical engineering & transports ,0203 mechanical engineering ,Law ,Ceramics and Composites ,Ultrasonic sensor ,Fiber ,Ultrasonic propagation ,0210 nano-technology ,Civil and Structural Engineering ,Dimensionless quantity - Abstract
This study investigated the similarity law of ultrasonic propagation in CFRP with concentrically curved fibers. The similarity law was formulated by introducing a new dimensionless number D. Additionally, the similarity law for a two-dimensionally propagating bulk wave was mathematically proven using the governing equation. A numerical simulation was conducted to visually demonstrate how this similarity law is held in CFRP with concentrically curved fibers. The simulation results revealed that the wavefronts of waves generated at different points had geometrically similar shapes when the D values for each wavefront were identical. The experimental visualization of ultrasonic propagation through a CFRP plate with concentrically curved fibers was also conducted, and the results revealed that the similarity law held in actual CFRP material specimens.
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- 2020
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53. UNSTEADY ANALYSIS OF A HETEROGENEOUS MATERIAL USING THE MULTISCALE SEAMLESS-DOMAIN METHOD
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Akira Todoroki, Yoshiro Suzuki, Masato Takahashi, and Yoshihiro Mizutani
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Physics ,Partial differential equation ,Computer Networks and Communications ,Control and Systems Engineering ,Mathematical analysis ,Computational Mechanics ,Finite difference method ,Thermal conduction ,Domain (software engineering) - Published
- 2018
54. Chemical Inhibitors of the Calcium Entry Channel TRPV6
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Katrin A. Bolanz, Yoshiro Suzuki, Matthias A. Hediger, and Christopher P. Landowski
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Male ,Pyrrolidines ,Miconazole ,Pharmaceutical Science ,chemical inhibitors ,Prostate cancer ,0302 clinical medicine ,Pharmacology (medical) ,RNA, Small Interfering ,Cells, Cultured ,0303 health sciences ,Voltage-dependent calcium channel ,prostate cancer ,Calcium Channel Blockers ,3. Good health ,Cell biology ,030220 oncology & carcinogenesis ,Molecular Medicine ,Female ,Biotechnology ,medicine.medical_specialty ,TRPV6 ,chemistry.chemical_element ,TRPV Cation Channels ,Breast Neoplasms ,Calcium ,03 medical and health sciences ,Inhibitory Concentration 50 ,breast cancer ,SDG 3 - Good Health and Well-being ,Internal medicine ,medicine ,Animals ,Humans ,030304 developmental biology ,Cell Proliferation ,Pharmacology ,Calcium metabolism ,business.industry ,Calcium channel ,Organic Chemistry ,Cancer ,Prostatic Neoplasms ,medicine.disease ,Endocrinology ,chemistry ,Cancer cell ,calcium channel ,Calcium Channels ,Econazole ,business - Abstract
Purpose: Calcium entry channels in the plasma membrane are thought to play a major role in maintaining cellular Ca2+ levels, crucial for growth and survival of normal and cancer cells. The calcium-selective channel TRPV6 is expressed in prostate, breast, and other cancer cells. Its expression coincides with cancer progression, suggesting that it drives cancer cell growth. However, no specific inhibitors for TRPV6 have been identified thus far. Methods: To develop specific TRPV6 inhibitors, we synthesized molecules based on the lead compound TH-1177, reported to inhibit calcium entry channels in prostate cancer cells in vitro and in vivo. Results: We found that one of our compounds (#03) selectively inhibited TRPV6 over five times better than TRPV5, whereas TH-1177 and the other synthesized compounds preferentially inhibited TRPV5. The IC50 value for growth inhibition by blocking endogenous Ca2+ entry channels in the LNCaP human prostate cancer cell line was 0.44 ± 0.07 μM compared to TH-1177 (50 ± 0.4 μM). Conclusions: These results suggest that compound #03 is a relatively selective and potent inhibitor for TRPV6 and that it is an interesting lead compound for the treatment of prostate cancer and other cancers of epithelial origin.
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- 2018
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55. TRPV6 Variants Interfere with Maternal-Fetal Calcium Transport through the Placenta and Cause Transient Neonatal Hyperparathyroidism
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Gen Nishimura, Katheryn Grand, David Chitayat, Fumio Takada, Hirotake Sawada, Makoto Tominaga, Kathryn Millar, Matthew A. Deardorff, Karen Chong, Heather M. McLaughlin, Megumi Obara, Amber Begtrup, Reiko Kushima, Shirley Shuster, Jennifer Harrington, Maian Roifman, Hiroshi Mutoh, and Yoshiro Suzuki
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0301 basic medicine ,Adult ,Male ,Placenta ,TRPV Cation Channels ,Biology ,medicine.disease_cause ,Compound heterozygosity ,Article ,Frameshift mutation ,03 medical and health sciences ,0302 clinical medicine ,Fetus ,Pregnancy ,Genetics ,medicine ,Intronic Mutation ,Missense mutation ,Humans ,Allele ,Maternal-Fetal Exchange ,Genetics (clinical) ,Exome sequencing ,Mutation ,Ion Transport ,Base Sequence ,Hyperparathyroidism ,Infant, Newborn ,Pedigree ,030104 developmental biology ,HEK293 Cells ,Transient Neonatal Hyperparathyroidism ,Calcium ,Female ,Calcium Channels ,030217 neurology & neurosurgery - Abstract
Transient neonatal hyperparathyroidism (TNHP) is etiologically a heterogeneous condition. One of the etiologies is an insufficient maternal-fetal calcium transport through the placenta. We report six subjects with homozygous and/or compound-heterozygous mutations in the gene encoding the transient receptor potential cation channel, subfamily V, member 6 (TRPV6), an epithelial Ca2+-selective channel associated with this condition. Exome sequencing on two neonates with skeletal findings consistent with neonatal hyperparathyroidism identified homozygous frameshift mutations before the first transmembrane domain in a subject born to first-cousins parents of Pakistani descent as well as compound-heterozygous mutations (a combination of a frameshift mutation and an intronic mutation that alters mRNA splicing) in an individual born to a non-consanguineous couple of African descent. Subsequently, targeted mutation analysis of TRPV6 performed on four other individuals (born to non-consanguineous Japanese parents) with similar X-rays findings identified compound-heterozygous mutations. The skeletal findings improved or resolved in most subjects during the first few months of life. We identified three missense variants (at the outer edges of the second and third transmembrane domains) that alter the localization of the TRPV6: one recurrent variant at the S2-S3 loop and two recurrent variants (in the fourth ankyrin repeat domain) that impair TRPV6 stability. Compound heterozygous loss-of-function mutations for the pathogenic frameshift allele and the allele with an intronic c.607+5G>A mutation resulted in the most severe phenotype. These results suggest that TNHP is an autosomal-recessive disease caused by TRPV6 mutations that affect maternal-fetal calcium transport.
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- 2018
56. Correction: Publisher Correction: Identification of a splice variant of mouse TRPA1 that regulates TRPA1 activity
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Makoto Tominaga, Kunitoshi Uchida, Yiming Zhou, and Yoshiro Suzuki
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Multidisciplinary ,Computer science ,Alternative splicing ,General Physics and Astronomy ,Identification (biology) ,General Chemistry ,Computational biology ,Article ,General Biochemistry, Genetics and Molecular Biology - Abstract
Transient receptor potential ankyrin 1 (TRPA1) protein is a nonselective cation channel. Although many studies suggest that TRPA1 is involved in inflammatory and neuropathic pain, its mechanism remains unclear. Here we identify an alternative splice variant of the mouse Trpa1 gene. TRPA1a (full-length) and TRPA1b (splice variant) physically interact with each other and TRPA1b increases the expression of TRPA1a in the plasma membrane. TRPA1a and TRPA1b co-expression significantly increases current density in response to different agonists without affecting their single-channel conductance. Exogenous overexpression of Trpa1b gene in wild-type and TRPA1KO DRG neurons also increases TRPA1a-mediated AITC responses. Moreover, expression levels of Trpa1a and Trpa1b mRNAs change dynamically in two pain models (complete Freund’s adjuvant-induced inflammatory pain and partial sciatic nerve ligation-induced neuropathic pain models). These results suggest that TRPA1 may be regulated through alternative splicing under these pathological conditions., TRPA1 is a transient receptor potential channel family member and is involved in the detection of nociceptive stimuli. Zhou et al. identify an alternative splice variant of TRPA1, which increases TRPA1 plasma expression and channel function, and enhances pain-like behaviour in mice.
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- 2018
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57. Trpm7 Protein Contributes to Intercellular Junction Formation in Mouse Urothelium
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Masaki Watanabe, Yoshiro Suzuki, Makoto Tominaga, Kunitoshi Uchida, Seiji Matsumoto, Naoyuki Miyazaki, Kazuyoshi Murata, and Hidehiro Kakizaki
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transient receptor potential channels (TRP channels) ,TRPM Cation Channels ,Inflammation ,Biology ,Biochemistry ,Cell junction ,Proinflammatory cytokine ,Mice ,In vivo ,旭川医科大学:博士(医学)(甲第512号) ,medicine ,Animals ,Patch clamp ,Urothelium ,Molecular Biology ,Barrier function ,Mice, Knockout ,animal model ,epithelial cell ,Gap junction ,学位授与年月日:平成29年6月30日 ,Gap Junctions ,Cell Biology ,Molecular biology ,cell junction ,inflammation ,Immunology ,medicine.symptom - Abstract
Trpm7 is a divalent cation-permeable channel that has been reported to be involved in magnesium homeostasis as well as cellular adhesion and migration. We generated urothelium-specific Trpm7 knock-out (KO) mice to reveal the function of Trpm7 in vivo. A Trpm7 KO was induced by tamoxifen and was confirmed by genomic PCR and immunohistochemistry. By using patch clamp recordings in primary urothelial cells, we observed that Mg(2+)-inhibitable cation currents as well as acid-inducible currents were significantly smaller in Trpm7 KO urothelial cells than in cells from control mice. Assessment of voiding behavior indicated a significantly smaller voided volume in Trpm7 KO mice (mean voided volume 0.28 ± 0.08 g in KO mice and 0.36 ± 0.04 g in control mice, p < 0.05, n = 6-8). Histological analysis showed partial but substantial edema in the submucosal layer of Trpm7 KO mice, most likely due to inflammation. The expression of proinflammatory cytokines TNF-α and IL-1β was significantly higher in Trpm7 KO bladders than in controls. In transmission electron microscopic analysis, immature intercellular junctions were observed in Trpm7 KO urothelium but not in control mice. These results suggest that Trpm7 is involved in the formation of intercellular junctions in mouse urothelium. Immature intercellular junctions in Trpm7 knock-out mice might lead to a disruption of barrier function resulting in inflammation and hypersensitive bladder afferent nerves that may affect voiding behavior in vivo.
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- 2015
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58. Lightning strike damage detection at a fastener using self-sensing TDR of composite plate
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Yoshihiro Mizutani, Keisuke Ohara, Akira Todoroki, Ryosuke Matsuzaki, and Yoshiro Suzuki
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Engineering ,business.product_category ,business.industry ,Insulator (electricity) ,Structural engineering ,Fibre-reinforced plastic ,Fastener ,Characteristic impedance ,Signal reflection ,Lightning strike ,Composite plate ,Transmission line ,Ceramics and Composites ,business ,Civil and Structural Engineering - Abstract
Carbon fibre reinforced polymer (CFRP) composites structures are widely used in aeroplane structures. When a lightning strike affects fasteners or leak electric current of the lightning strike arrives at fasteners, the fasteners play serve as conducting electrodes for the CFRP plate. This current might cause complicated damage in the CFRP plate. The authors have developed self-sensing TDR to detect damage. Self-sensing TDR is used in this study to monitor lightning strike damage around a CFRP plate fastener hole. The lightning strike electric current is applied directly to a fastener. Thereafter, self-sensing TDR is applied. The lightning strike damage is investigated using cross-sectional inspection to clarify the mechanisms of the monitoring using TDR. Results show that the method can detect a 30 kA strike. Peeling of the GFRP insulator causes a characteristic impedance change, which in turn causes signal reflection of the transmission line.
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- 2015
59. Impact damage detection of a carbon-fibre-reinforced-polymer plate employing self-sensing time-domain reflectometry
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Yoshiro Suzuki, Kazuhiro Yamada, Ryosuke Matsuzaki, Akira Todoroki, and Yoshihiro Mizutani
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chemistry.chemical_classification ,Materials science ,business.industry ,Delamination ,Polymer ,Smart material ,Line (electrical engineering) ,chemistry ,Electrical resistance and conductance ,Nondestructive testing ,Ceramics and Composites ,Time domain ,Composite material ,Reflectometry ,business ,Civil and Structural Engineering - Abstract
A non-destructive inspection method of carbon fibre reinforced polymer (CFRP) is self-sensing technology that uses carbon fibres as sensors. The technology applies electric current to composites and measures the electrical resistance change to detect damage. Although the technique detects damage precisely, it requires many electrodes on the CFRP surface. Time-domain reflectometry (TDR) has previously been proposed to detect damage over a wide area with a small number of electrodes and applied to detect fibre breakage in unidirectional CFRP ply specimens. In the present paper, experiments are conducted for a cross-ply CFRP laminate subjected to impact damage. Three impact loads are applied and the damage is inspected employing self-sensing TDR and a micro-strip line. Results show that the self-sensing TDR can be applied to laminated CFRP structures that have several fibre directions and when damage such as a delamination crack extends under or close to the micro-strip line.
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- 2015
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60. Design of eddy current-based dielectric constant meter for defect detection in glass fiber reinforced plastics
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Akira Todoroki, Yoshiro Suzuki, Yoshihiro Mizutani, and Koichi Mizukami
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Permittivity ,Materials science ,Mechanical Engineering ,Glass fiber ,Dielectric ,Fibre-reinforced plastic ,Condensed Matter Physics ,Magnetic field ,law.invention ,law ,Eddy-current testing ,Eddy current ,Metre ,General Materials Science ,Composite material - Abstract
This paper presents the design of an eddy current testing probe for inspection of non-conductive glass fiber reinforced plastics. Because the magnetic field contains information pertaining to the permittivity of materials under test, eddy current testing offers the possibility of flaw detection in non-conductive materials through detection of the difference in permittivity between the intact part and the defective part of each material. We analytically investigated the design of a probe suitable for dielectric constant measurements. Experimental studies proved that the proposed probe can detect slit defects and flat-bottomed holes located 2 mm away from the surface of the glass fiber reinforced plastic samples.
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- 2015
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61. Multiscale seamless-domain method for linear elastic analysis of heterogeneous materials
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Yoshiro Suzuki
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Numerical Analysis ,Applied Mathematics ,Mathematical analysis ,Linear elasticity ,General Engineering ,02 engineering and technology ,01 natural sciences ,010101 applied mathematics ,020303 mechanical engineering & transports ,0203 mechanical engineering ,Calculus ,Meshfree methods ,0101 mathematics ,Elasticity (economics) ,Mathematics - Published
- 2015
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62. Analytical solutions to eddy current in carbon fiber-reinforced composites induced by line current
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Akira Todoroki, Yoshihiro Mizutani, Yoshiro Suzuki, and Koichi Mizukami
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010302 applied physics ,Materials science ,Eddy-current sensor ,Mechanical Engineering ,02 engineering and technology ,Eddy current brake ,021001 nanoscience & nanotechnology ,01 natural sciences ,law.invention ,Magnetic field ,Mechanics of Materials ,law ,Electrical resistivity and conductivity ,0103 physical sciences ,Ceramics and Composites ,Eddy current ,Skin effect ,Current (fluid) ,Composite material ,0210 nano-technology ,Anisotropy ,Physics::Atmospheric and Oceanic Physics - Abstract
This paper presents analytical solutions to eddy current distribution in carbon fiber-reinforced plastics induced by line current. Derived solutions show that eddy current distribution in unidirectional carbon fiber composite is dependent only on electrical conductivity in the drive current direction when the drive current is directed in the fiber direction or the transverse direction. Moreover, according to the derived analytical solution, skin depth of eddy current depends not only on frequency of drive current but on lift-off and width of the drive current unlike general expression of skin depth. Finally, we discuss improvement of sensitivity of eddy current conductivity sensor using analytical solutions. It is found that analytical solutions can clearly divide effects of magnetic field from drive current and that from eddy current. Sensitivity of eddy current sensor can be improved by 10 times placing pickup coil at region where the effect of magnetic field from eddy current is large.
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- 2015
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63. Three-dimensional reconstruction of resin flow using capacitance sensor data assimilation during a liquid composite molding process: A numerical study
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Yoshiro Suzuki, Yoshihiro Mizutani, Masayuki Murata, Akira Todoroki, and Ryosuke Matsuzaki
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Materials science ,Data assimilation ,Mechanics of Materials ,Capacitive sensing ,Composite number ,Stochastic simulation ,Void (composites) ,Ceramics and Composites ,Ensemble Kalman filter ,Molding (process) ,Composite material ,Capacitance - Abstract
Liquid composite molding (LCM) is a method to manufacture fiber-reinforced composites, where dry fabric reinforcement is impregnated with a resin in a molding apparatus. However, the inherent process variability changes resin flow patterns during mold filling, which in turn may cause void formation. We propose a method to reconstruct three-dimensional resin flow in LCM, without embedding sensors into the composite structure. Capacitance measured from pairs of electrodes on molding tools and the stochastic simulation of resin flow during an LCM process are integrated by a sequential data assimilation method based on the ensemble Kalman filter; then, three-dimensional resin flow and permeability distribution are estimated simultaneously. The applicability of this method is investigated by numerical experiments, characterized by different spatial distributions of permeability. We confirmed that changes in resin flow caused by spatial permeability variations could be captured and the spatial distribution of permeability could be estimated by the proposed method.
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- 2015
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64. PS0014-241 Experimental and Analytical Assessment of Electrical Resistance Change by Inner Damage of CFRP Leaf Springs for a Rolling Stock Bogie 'efWING'
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Yoshihiro Mizutani, Akira Todoroki, Teruhisa Nakaoka, Yoshiro Suzuki, Yusuke Nishio, and Mitsue Masayuki
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Engineering ,Electrical resistance and conductance ,Leaf spring ,business.industry ,Structural engineering ,Smart material ,business ,Stock (geology) ,Bogie - Published
- 2015
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65. Supercapacitor Consisting of a Form Core Sandwich with Woven Carbon Fiber Skin
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Yoshiro Suzuki, Yoshihiro Mizutani, Akira Todoroki, and Tomohiro Sawada
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Supercapacitor ,Capacitor ,Materials science ,law ,Composite number ,Glass fiber ,Internal resistance ,Composite material ,Capacitance ,Sheet resistance ,Separator (electricity) ,law.invention - Abstract
Structural capacitors are composite structures that function as energy storage capacitors. Parallel plate-type capacitors have the advantage of high voltage resistance, but are limited by low capacitance. An electric double-layer capacitor with a composite structure using a solid polymer electrolyte matrix with a glass fiber fabric separator has recently been developed. However, the solid polymer electrolyte caused the capacitor to possess high internal resistance. In the present study, a new design of supercapacitor using a form core sandwich with high water retention is proposed and experimentally investigated. Activated carbon sheets are used as electrodes on the form core sandwich to make a supercapacitor. Woven carbon fabric is used as lead wires of the supercapacitor. The resulting supercapacitor displays a low surface resistance of 810 Ωcm2 and high areal capacitance of 520 mF/cm2.
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- 2015
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66. OS0415-251 Frequency dependence of b-value used for AE analysis
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Yuto Hata, Akira Todoroki, Doyun Jung, Yoshihiro Mizutani, and Yoshiro Suzuki
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Physics ,Frequency dependence ,Atomic physics - Published
- 2015
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67. Self-Sensing TDR for Bearing Failure Detection of CFRP Laminate Fastener Hole with Particular Reference to the Effect of Fasteners
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Akira Todoroki, Ryosuke Matsuzaki, Keisuke Ohara, Yoshiro Suzuki, and Yoshihiro Mizutani
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Carbon fiber reinforced polymer ,Bearing (mechanical) ,Self sensing ,Materials science ,business.product_category ,business.industry ,Structural engineering ,Fastener ,law.invention ,law ,Transmission line ,Time domain ,Composite material ,business ,Reflectometry ,Electrical impedance - Abstract
Carbon fiber reinforced polymer composites (CFRP) have been applied to aerospace and automobile structures. For many CFRP structures, mechanical metallic fasteners are usually adopted. For the fasteners used in internal structures such as a wing box, the damage to the CFRP structures around fastener holes is visually quite difficult to find. A simple method to find the damage around fastener holes is required. In this study a self-sensing time domain reflectometry (TDR) method is newly applied to detect bearing failure around the fastener holes of CFRP structures. A microstrip-line method is generally used to create a transmission line. When the transmission line is mounted near the metallic fasteners, they may affect the impedance of the transmission line. In this study, the effect of distance between the fasteners and the transmission line was numerically investigated using a finite difference time domain analysis method. After finding the appropriate distance, experiments were performed to detect the bearing failure around a fastener hole. The experiments showed the performance of the self-sensing TDR for detecting bearing failure.
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- 2015
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68. OS1006-238 Internal damage detection of CFRP by AE monitoring during impact
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Yoshiro Suzuki, Akira Todoroki, Yoshihiro Mizutani, and Takeshi Ashizawa
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Damage detection ,Materials science ,business.industry ,Structural engineering ,business - Published
- 2015
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69. A unique mode of keratinocyte death requires intracellular acidification.
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Takeshi Matsui, Nanako Kadono-Maekubo, Yoshiro Suzuki, Yuki Furuichi, Keiichiro Shiraga, Hiroyuki Sasaki, Azusa Ishida, Sonoko Takahashi, Takaharu Okada, Kiminori Toyooka, Sharif, Jafar, Takaya Abe, Hiroshi Kiyonari, Makoto Tominaga, Atsushi Miyawaki, and Masayuki Amagai
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TRP channels ,ACIDIFICATION ,NUCLEAR DNA ,COMMERCIAL products ,CELL death ,CURCUMIN - Abstract
The stratum corneum (SC), the outermost epidermal layer, consists of nonviable anuclear keratinocytes, called corneocytes, which function as a protective barrier. The exact modes of cell death executed by keratinocytes of the upper stratum granulosum (SG1 cells) remain largely unknown. Here, using intravital imaging combined with intracellular Ca2+- and pH-responsive fluorescent probes, we aimed to dissect the SG1 death process in vivo. We found that SG1 cell death was preceded by prolonged (~60 min) Ca2+ elevation and rapid induction of intracellular acidification. Once such intracellular ionic changes were initiated, they became sustained, irreversibly committing the SG1 cells to corneocyte conversion. Time-lapse imaging of isolated murine SG1 cells revealed that intracellular acidification was essential for the degradation of keratohyalin granules and nuclear DNA, phenomena specific to SC corneocyte formation. Furthermore, intravital imaging showed that the number of SG1 cells exhibiting Ca2+ elevation and the timing of intracellular acidification were both tightly regulated by the transient receptor potential cation channel V3. The functional activity of this protein was confirmed in isolated SG1 cells using whole-cell patch-clamp analysis. These findings provide a theoretical framework for improved understanding of the unique molecular mechanisms underlying keratinocyte-specific death mode, namely corneoptosis. [ABSTRACT FROM AUTHOR]
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- 2021
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70. TRPV5 and TRPV6 Calcium-Selective Channels
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Ji-Bin Peng, Matthias A. Hediger, Gergely Gyimesi, and Yoshiro Suzuki
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Kidney ,TRPV6 ,TRPV5 ,chemistry.chemical_element ,Calcium ,Apical membrane ,TRPV ,Intestinal absorption ,Cell biology ,Transient receptor potential channel ,medicine.anatomical_structure ,chemistry ,medicine ,570 Life sciences ,biology ,610 Medicine & health - Abstract
The epithelial calcium (Ca2+) channels TRPV5 and TRPV6 are members of the transient receptor potential (TRP) channel family TRPV (“V” for vanilloid) subgroup. TRPV5 and TRPV6 play major roles in the maintenance of blood Ca2+ levels in higher organisms. Both channels exhibit similarities in many ways, as they share a high level (75%) of amino acid identity, comparable functional properties, and similar mechanisms of regulation. Also, they were discovered using similar cloning strategies [1,2]. Yet, their physiological contributions toward maintaining a systemic calcium balance are distinct. In addition, the following three key features distinguish TRPV5 and TRPV6 from other members of the TRP superfamily of cation channels: (1) high selectivity for Ca2+ over other cations, (2) apical membrane localization in Ca2+-transporting epithelial tissues, and (3) responsiveness to 1,25-dihydroxyvitamin D3 (1,25[OH]2D3) [3,4]. These features make TRPV5 and TRPV6 ideally suited to facilitate intestinal absorption and renal reabsorption of Ca2+, serving as apical Ca2+ entry channels in transepithelial Ca2+ transport [5,6]. A major difference between the properties of TRPV5 and TRPV6 lies in their tissue distribution: TRPV5 is predominantly expressed in the distal convoluted tubules (DCT) and connecting tubules (CNT) of the kidney, with limited expression in extrarenal tissues [1,7]. In contrast, TRPV6 exhibits a broader expression pattern, showing prominent expression in the intestine with additional expression in the kidney [8–10], placenta, epididymis, exocrine tissues (i.e., pancreas, prostate, salivary gland, sweat gland), and a few other tissues [11–13]. Thus, while TRPV5 plays a key role in determining the level of urinary Ca2+ excretion, the physiological roles of TRPV6 are not limited to intestinal Ca2+ absorption. Much progress has recently been made in understanding the roles of TRPV5 and TRPV6 channels in the kidney [14], intestine [15], placenta [16], and epididymis [17]. However, their roles in other organs have as yet not been fully investigated.In this chapter, we review the current status of our knowledge of the physiological and pathological roles of TRPV5 and TRPV6 and discuss a variety of techniques that have led to a deeper understanding of these channels. We review the identification strategies of TRPV5 and TRPV6 in searches for Ca2+ absorption channels, as well as specific techniques used to reveal their key features. These include radiotracer Ca2+ uptake and electrophysiology procedures, structure-function studies, methods to identify regulatory interacting partners, genetically engineered animals, strategies to study the role of TRPV6 in cancers, procedures for the development of small-molecule modulators of TRPV6 and TRPV5, the evaluation of variations/mutations in humans, and 3D structural determination. For additional information about TRPV5 and TRPV6, we would like to refer the interested reader to other comprehensive review articles [3–6,18].
- Published
- 2017
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71. Biphasic Renal Sympathetic Response to Hemorrhagic Hypotension in Mice
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Tao Zhang, Wei Yang, Toshishige Shibamoto, Yasutaka Kurata, Kunitoshi Uchida, Makoto Tominaga, Yoshiro Suzuki, Mamoru Tanida, and Yuhichi Kuda
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0301 basic medicine ,Male ,medicine.medical_specialty ,Sympathetic nervous system ,Sympathetic Nervous System ,medicine.medical_treatment ,TRPV Cation Channels ,Vagotomy ,Critical Care and Intensive Care Medicine ,Inhibitory postsynaptic potential ,Kidney ,03 medical and health sciences ,Mice ,0302 clinical medicine ,Heart Rate ,Internal medicine ,Heart rate ,medicine ,Animals ,business.industry ,Kidney metabolism ,Hemorrhagic hypotension ,Mice, Inbred C57BL ,030104 developmental biology ,medicine.anatomical_structure ,Endocrinology ,Renal physiology ,Emergency Medicine ,Female ,Hypotension ,business ,030217 neurology & neurosurgery - Abstract
The inhibitory responses of renal sympathetic nerve activity (RSNA) and heart rate (HR) to sustained hemorrhagic shock occurred in anesthetized rats, but have not yet been determined in mice. Here, we investigated the responses of RSNA and HR to hemorrhagic hypotension in anesthetized mice, with an emphasis on the molecule-based mechanism for roles of afferent vagal nerves.RSNA, HR, and mean systemic arterial pressure were continuously measured in male pentobarbital-anesthetized C57BL/6N mice. Hemorrhagic hypotension of 50 mmHg was evoked and maintained for 10 min.During hemorrhagic hypotension, RSNA initially increased and then sustainedly decreased, while HR progressively decreased. Vagotomy eliminated the second-phase sympathoinhibition and bradycardia, and carotid sinus denervation with vagotomy abolished the initial renal sympathoexcitation. The renal sympathoinihibition during hemorrhagic hypotension of 50 mmHg was eliminated in mice pretreated with a transient receptor potential vanilloid type 1 channel (TRPV1) inhibitor, capsazepine, and in TRPV1 knockout (TRPV1) mice, but not in TRPV4 knockout mice. The bradycardia response to hemorrhagic hypotension was also absent in TRPV1 mice and mice pretreated with capsazepine.Hemorrhagic hypotension in anesthetized mice causes biphasic responses of RSNA with an initial increase, followed by a sustained decrease, and a progressive decrease in HR. The initial sympathoexcitation is mediated by carotid sinus baroreceptors, while the later sympathoinhibition and bradycardia are mediated via the TRPV1 signals of vagal afferents.
- Published
- 2017
72. 高強度化学繊維によるワイヤ駆動のための基礎的検討 第四報:長軸間距離試験機の製作と周波数応答
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Yoshiro Suzuki, Atsushi Takata, Yoshihiro Mizutani, Hiroyuki Nabae, Koichi Suzumori, and Gen Endo
- Abstract
近年,高機能,高性能な化学繊維の開発が盛んである.筆者らはこれらの化学繊維を用いたワイヤを高強度化学繊維ワイヤと呼び,金属ワイヤに代替してこれらの特性を活かしたロボットの実現を目指している.本報では,高強度化学繊維ワイヤが駆動系の周波数特性に与える影響を検証するために長軸間距離試験機を製作し,周波数特性試験を行った.また,ワイヤの粘弾性測定から長軸間距離試験機の伝達関数を求め,測定した周波数応答と比較しおおむね一致することを確認した., Synthetic fiber ropes, which are lightweight and have high tensile strength and flexibility, have attracted attention as an alternative to stainless steel wire rope. This study clarifies various physical characteristics of synthetic fiber ropes to design a tendon-driven mechanism. This paper investigates a viscoelasticity model for Ultra High molecular weight Polyethylene (UHPE) rope and its dynamic property applied to a long distant antagonistic tendon-driven servo system. We confirm that UHPE can be modeled by four element model, and obtained its transfer function of a tendon-driven servo system. The validity of the transfer function was confirmed by a frequency response experiment. %This paper takes note of performance of synthetic fiber rope on tendon-driven servo system. %We estimated a viscoelasticity of a UHPE(Ultra High Molecular Weight Polyethylene) rope by four element model and using the viscoelasticity to obtained the transfer function of a tendon-driven servo system.
- Published
- 2017
73. Smart lightning protection skin for real-time load monitoring of composite aircraft structures under multiple impacts
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Akira Todoroki, Yoshihiro Mizutani, Toyoaki Suzuki, and Yoshiro Suzuki
- Subjects
Materials science ,Impact behavior ,Non-destructive testing ,Radius ,Interval (mathematics) ,Collision ,Lightning ,Electrical resistance and conductance ,Mechanics of Materials ,Position (vector) ,Delamination ,Ceramics and Composites ,Ultrasonic sensor ,Current (fluid) ,Composite material - Abstract
We experimentally test a previously reported lightning protection sheet (LPS) sensor to detect impacts within a short collision interval. The exact loading position is achieved using a two-step method. Our sensor sheet is flexible and can easily be attached to different shaped structures. Current flows in the sensor only during loading and our quick switching system identifies the real-time x, y coordinates of the loading position. Using this method multiple impacts can be detected when the time difference between two impacts is larger than 10 ms. The position of a single impact is estimated within 16 mm. This means that detailed inspection needs to be conducted only over a circular area with a radius about a few centimeters. Our method is ideally suited for aircraft components and it reduces costs and saves time as only small specific areas require inspection using ultrasonic or electrical resistance techniques.
- Published
- 2014
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74. Functional Role for Piezo1 in Stretch-evoked Ca2+ Influx and ATP Release in Urothelial Cell Cultures
- Author
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Schuichi Koizumi, Hiroshi Nakagomi, Yoshiro Suzuki, Makoto Tominaga, Masaki Watanabe, Tsutomu Mochizuki, Tatsuya Miyamoto, Yasunori Takayama, Masayuki Takeda, and Satoru Kira
- Subjects
Urothelial Cell ,Mechanosensation ,PIEZO1 ,Stimulation ,Cell Biology ,Biology ,urologic and male genital diseases ,Biochemistry ,female genital diseases and pregnancy complications ,Bladder Urothelium ,Cell biology ,Urothelium ,Mechanotransduction ,Molecular Biology ,Ion transporter - Abstract
The urothelium is a sensory structure that contributes to mechanosensation in the urinary bladder. Here, we provide evidence for a critical role for the Piezo1 channel, a newly identified mechanosensory molecule, in the mouse bladder urothelium. We performed a systematic analysis of the molecular and functional expression of Piezo1 channels in the urothelium. Immunofluorescence examination demonstrated abundant expression of Piezo1 in the mouse and human urothelium. Urothelial cells isolated from mice exhibited a Piezo1-dependent increase in cytosolic Ca(2+) concentrations in response to mechanical stretch stimuli, leading to potent ATP release; this response was suppressed in Piezo1-knockdown cells. In addition, Piezo1 and TRPV4 distinguished different intensities of mechanical stimulus. Moreover, GsMTx4, an inhibitor of stretch-activated channels, attenuated the Ca(2+) influx into urothelial cells and decreased ATP release from them upon stretch stimulation. These results suggest that Piezo1 senses extension of the bladder urothelium, leading to production of an ATP signal. Thus, inhibition of Piezo1 might provide a promising means of treating bladder dysfunction.
- Published
- 2014
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75. Potential role of transient receptor potential (TRP) channels in bladder cancer cells
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Ryohei Hattori, Yoshiro Suzuki, Hideki Mizuno, Masaki Watanabe, Takaaki Sokabe, Momokazu Gotoh, Makoto Tominaga, and Tokunori Yamamoto
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Male ,TRPV4 ,medicine.medical_specialty ,Physiology ,TRPM Cation Channels ,TRPV Cation Channels ,Biology ,Mice ,Transient receptor potential channel ,TRPM7 ,Cell Line, Tumor ,Internal medicine ,medicine ,Animals ,RNA, Messenger ,Cells, Cultured ,Cell Proliferation ,Mice, Inbred C3H ,Bladder cancer ,Cancer ,medicine.disease ,Endocrinology ,Urinary Bladder Neoplasms ,Cell culture ,Cancer cell ,Cancer research ,Calcium ,Calcium Channels ,Urothelium ,Intracellular - Abstract
Transient receptor potential (TRP) channels play important roles in thermal, chemical, and mechanical sensation in various tissues. In this study, we investigated the differences in urothelial TRP channels between normal urothelial cells and bladder cancer cells. TRPV2 and TRPM7 expression levels and TRPV2 activator-induced intracellular Ca(2+) increases were significantly higher, whereas TRPV4 expression and TRPV4 activator-induced intracellular Ca(2+) increases were significantly lower in mouse bladder cancer (MBT-2) cells compared to normal mouse urothelial cells. The proliferation rate of MBT-2 cells overexpressing dominant-negative TRPV2 was significantly increased. In contrast, treatment with TRPV2 activators significantly decreased the proliferation rate. TRPM7-overexpressing MBT-2 cells proliferated more slowly, as compared to mock-transfected cells. Moreover, expression of dominant-negative TRPV2 significantly decreased plasma membrane Ca(2+) permeability of MBT-2 cells as compared to that in mock-transfected cells. Increases in the expression of TRPV2 mRNA, immunoreactivity, and TRPV2 activator-induced intracellular Ca(2+) were also observed in T24 human bladder cancer cells. These results suggested that TRPV2 and TRPM7 were functionally expressed in bladder cancer cells and served as negative regulators of bladder cancer cell proliferation, most likely to prevent excess mechanical stresses.
- Published
- 2014
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76. Analytical benchmark example for risk allocation in structural optimization
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Yoshiro Suzuki and Raphael T. Haftka
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Engineering ,Mathematical optimization ,Control and Optimization ,Safety factor ,business.industry ,Probabilistic-based design optimization ,Monte Carlo method ,Topology optimization ,Truss ,Computer Graphics and Computer-Aided Design ,Computer Science Applications ,Control and Systems Engineering ,Simple (abstract algebra) ,Benchmark (computing) ,business ,Software ,Reliability (statistics) - Abstract
Recently, Rozvany and Maute presented a simple problem of topology optimization under uncertainty with a single load condition that can be solved without Monte Carlo simulation. This note extends this idea to a two-bar truss under two load conditions for the purpose of illustrating differences between deterministic designs and reliability–based ones in terms of risk allocation. For this example, for the same probability of failure, a deterministic design based on the same safety factor for both loads can be substantially heavier than the reliability–based design. The difference in weight is due to very different risk allocation between the two failure modes.
- Published
- 2014
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77. Finite heterogeneous element method using sliced microstructures for linear elastic analysis
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Yoshiro Suzuki
- Subjects
Numerical Analysis ,Materials science ,Applied Mathematics ,Mathematical analysis ,Linear elasticity ,General Engineering ,Calculus ,Elasticity (economics) ,Microstructure ,Finite element method - Published
- 2014
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78. Electrical Resistance Change of Carbon/Epoxy Composite Laminates under Cyclic Loading under Damage Initiation Limit
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Yoshihiro Mizutani, Akira Todoroki, Tesuo Yasuoka, Yoshiro Suzuki, and Daichi Haruyama
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Carbon fiber reinforced polymer ,Materials science ,Electrical resistance and conductance ,visual_art ,Electrode ,Composite number ,Contact resistance ,visual_art.visual_art_medium ,Epoxy ,Composite material ,Composite laminates ,Electrical contacts - Abstract
Self-sensing multifunctional composite has sensing function using electrical resistance changes. Carbon Fiber Reinforced Polymer (CFRP) composite is one of the self-sensing multifunctional composites. For the reliability of the self-sensing, electrical contact between the lead wire and the carbon fibers is the most important issue. The present study focuses on the effect of the cyclic loading of lower applied strain range than the fatigue damage level. As a result, the electrical contact resistance at the copper electrode increased with the increase of cycles. That means that the electrical change at the electrodes must be considered for the long-term self-sensing monitoring system. When a four-probe method is used to measure the electrical resistance, the contact resistance effect is minimized. Moreover, angle-ply laminates have plastic deformation caused by shear loading, and that causes electrical resistance decrease during the cyclic loading. Cross-ply laminates of CFRP composites have no electrical resistance increase without damage. Quasi-isotropic laminates of CFRP composites, however, have electrical resistance decrease with the increase of the number of cycles because of the plastic deformation of the angle-ply laminates.
- Published
- 2014
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79. Correction to: Hypotonicity-induced cell swelling activates TRPA1
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Yasunori Takayama, Fumitaka Fujita, Kunitoshi Uchida, Makoto Tominaga, Masayuki Takaishi, and Yoshiro Suzuki
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Patch-Clamp Techniques ,Physiology ,business.industry ,Cell swelling ,Internet portal ,Correction ,Anatomy ,Human physiology ,Cell Enlargement ,HEK293 Cells ,Hypotonic Solutions ,Medicine ,Humans ,Calcium ,business ,TRPA1 Cation Channel - Abstract
The article Hypotonicity-induced cell swelling activates TRPA1, written by Fumitaka Fujita, Kunitoshi Uchida, Yasunori Takayama, Yoshiro Suzuki, Masayuki Takaishi and Makoto Tominaga, was originally published electronically on the publisher’s internet portal (currently SpringerLink) on 16 June 2017 without open access.
- Published
- 2019
80. Layout optimization and prototype evaluation of curvilinearly skin/stiffener structure using 3D printer
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Yoshiro Suzuki, Ryosuke Matsuzaki, Akira Todoroki, Yoshiyasu Hirano, Koki Sakamoto, and Kenta Mitsui
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Engineering drawing ,Computer science ,Structure (category theory) ,3d printer - Published
- 2019
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81. OS0417-197 Lamb wave tomography by manual scanning
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Takehiro Miki, Yoshiro Suzuki, Akira Todoroki, and Yoshihiro Mizutani
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Optics ,Lamb waves ,Materials science ,business.industry ,Tomography ,business - Published
- 2015
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82. Fatigue damage detection of CFRP using the electrical resistance change method
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Daichi Haruyama, Akira Todoroki, Yoshihiro Mizutani, and Yoshiro Suzuki
- Subjects
Materials science ,Electrical resistance and conductance ,business.industry ,Delamination ,Cyclic loading ,Fatigue damage ,sense organs ,Structural engineering ,Deformation (engineering) ,business ,Matrix cracking ,Electrical contacts - Abstract
Electrical resistance change measurements were performed, to detect fatigue damage of a quasi-isotropic CFRP and cross-ply CFRP laminates. A four-probe method was used to measure the exact electrical resistance change. A three-probe method was used to measure the electrical contact resistance change, during long cyclic loading. The specimen side surface was observed using a video-microscope to detect damage. The measured electrical resistance changes were compared with the observed damage. The results of this study show that the electrical resistance increase of the quasi-isotropic laminate was caused by a delamination crack between ±45° plies. Matrix cracking caused a small electrical resistance increase of the cross-ply laminate, but the decreased electrical resistance caused by the shear-plastic deformation impedes matrix-cracking detection.
- Published
- 2013
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83. Electrical Resistance Change of Self-Sensing CFRP Laminates during Cyclic Loading
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Yoshiro Suzuki, Akira Todoroki, Daichi Haruyama, Tetsuo Yasuoka, and Yoshihiro Mizutani
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Materials science ,Self sensing ,Electrical resistance and conductance ,Mechanics of Materials ,Mechanical Engineering ,Cyclic loading ,General Materials Science ,Composite material - Published
- 2013
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84. Blood pressure differences between office and home settings among Japanese normotensive subjects and hypertensive patients
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Shouhei Yuasa, Hareaki Yamamoto, Keiichi Chin, Yoshiro Suzuki, Hisao Mori, Hiroshi Ukai, Takuma Katsumata, and Satoshi Umemura
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Adult ,Male ,medicine.medical_specialty ,Physiology ,Office Visits ,Office visits ,Diastole ,Blood Pressure ,030204 cardiovascular system & hematology ,03 medical and health sciences ,0302 clinical medicine ,Japan ,Internal medicine ,Internal Medicine ,Medicine ,Humans ,In patient ,Statistical analysis ,030212 general & internal medicine ,Morning ,Aged ,business.industry ,Blood Pressure Determination ,Middle Aged ,Blood pressure ,Hypertension ,Cardiology ,Female ,Cardiology and Cardiovascular Medicine ,business ,White Coat Hypertension ,circulatory and respiratory physiology - Abstract
This study attempted to clarify the differences in blood pressure (BP) between the office (clinic) and home settings in patients with controlled, sustained, masked or white-coat hypertension. The following formula was used: office mean systolic BP (omSBP)-mean morning home SBP (mmhSBP)/office mean diastolic BP (omDBP)-mean morning home DBP (mmhDBP). The paired t-test was used for statistical analysis. The omSBP-mmhSBP/omDBP-mmhDBP calculation yielded the following results: among normotensive subjects, -1.1±11.2/-1.7±8.5 mm Hg (mean SBP and mean DBP were higher at home than in the office; n=451, P=0.038 in SBP, P=0.000 in DBP); in controlled hypertensive patients, -0.42±10.9/-2.2±8.2 mm Hg (n=1362, P=0.160 in SBP, P=0.000 in DBP); among sustained hypertensive patients, 5.6±14.7/0.048±9.9 mm Hg (n=1370, P=0.000 in SBP, P=0.857 in DBP); in masked hypertensive patients, -15.3±12.9/-9.3±9.5 mm Hg (n=1308, both P=0.000); and among white-coat hypertensive patients, 23.7±13.2/8.2±9.1 mm Hg (n=580, both P=0.000). Our results showed a difference of 5 mm Hg in SBP among sustained hypertensive patients, as recommended by the Japanese Society of Hypertension Guidelines for the Management of Hypertension; however, in other hypertensive patient types, the differences in SBP and DBP between office and home measurements differed by >5 mm Hg. Office and home BP measurements should be interpreted cautiously, keeping in mind the clinical setting.
- Published
- 2016
85. Lack of TRPV2 impairs thermogenesis in mouse brown adipose tissue
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Shigeo Wakabayashi, Teruo Kawada, Yasunori Takayama, Kunitoshi Uchida, Wu-Ping Sun, Min-Ji Kim, Makoto Tominaga, Yiming Zhou, Yoshiro Suzuki, Nobuyuki Takahashi, Tsuyoshi Goto, and Yuko Iwata
- Subjects
0301 basic medicine ,medicine.medical_specialty ,Autocommentary ,TRPV2 ,Adipose tissue ,TRPV Cation Channels ,White adipose tissue ,Biology ,Diet, High-Fat ,Biochemistry ,03 medical and health sciences ,Transient receptor potential channel ,Mice ,0302 clinical medicine ,Adipose Tissue, Brown ,Internal medicine ,Receptors, Adrenergic, beta ,Brown adipose tissue ,Genetics ,medicine ,Animals ,Obesity ,Molecular Biology ,Cells, Cultured ,PRDM16 ,Voltage-dependent calcium channel ,Cell Differentiation ,Thermogenesis ,Articles ,Mice, Inbred C57BL ,Adipocytes, Brown ,030104 developmental biology ,medicine.anatomical_structure ,Endocrinology ,Calcium ,Calcium Channels ,030217 neurology & neurosurgery - Abstract
Brown adipose tissue (BAT), a major site for mammalian non-shivering thermogenesis, could be a target for prevention and treatment of human obesity. Transient receptor potential vanilloid 2 (TRPV2), a Ca(2+)-permeable non-selective cation channel, plays vital roles in the regulation of various cellular functions. Here, we show that TRPV2 is expressed in brown adipocytes and that mRNA levels of thermogenic genes are reduced in both cultured brown adipocytes and BAT from TRPV2 knockout (TRPV2KO) mice. The induction of thermogenic genes in response to β-adrenergic receptor stimulation is also decreased in TRPV2KO brown adipocytes and suppressed by reduced intracellular Ca(2+) concentrations in wild-type brown adipocytes. In addition, TRPV2KO mice have more white adipose tissue and larger brown adipocytes and show cold intolerance, and lower BAT temperature increases in response to β-adrenergic receptor stimulation. Furthermore, TRPV2KO mice have increased body weight and fat upon high-fat-diet treatment. Based on these findings, we conclude that TRPV2 has a role in BAT thermogenesis and could be a target for human obesity therapy.
- Published
- 2016
86. Multiscale seamless-domain method for solving nonlinear heat conduction problems without iterative multiscale calculations
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Akira Todoroki, Yoshihiro Mizutani, and Yoshiro Suzuki
- Subjects
numerical analysis ,Computer science ,meshfree method ,Numerical analysis ,Mathematical analysis ,finite element method ,homogenization ,heat conduction ,010103 numerical & computational mathematics ,Thermal conduction ,composite material ,01 natural sciences ,Homogenization (chemistry) ,Finite element method ,multiscale solver ,010101 applied mathematics ,Nonlinear system ,TJ1-1570 ,nonlinear problem ,Mechanical engineering and machinery ,0101 mathematics - Abstract
In this paper, we applied a multiscale numerical scheme called the seamless-domain method (SDM) to nonlinear elliptic boundary value problems. Although the SDM is meshfree, it can obtain a high-resolution solution whose dependent-variable gradient(s) is sufficiently smooth and continuous. The SDM models with only coarse-grained points can produce accurate solutions for both linear heat conduction problems and linear elastic problems. This manuscript presents a simple nonlinear solver for the SDM analysis of heterogeneous materials. Although the solver can easily approximate the solutions to nonlinear multiscale problems, it does not require an iterative multiscale analysis at every convergence calculation. In other words, the proposed scheme does not completely interactively couple the multiple scales. We present numerical examples of nonlinear stationary heat conduction analyses of heterogeneous fields and compare the SDM model, the direct finite-element model, and the homogenized model based on the homogenization theory. For a real heterogeneous structure (graphite fiber composite) that did not have strong material nonlinearities, the SDM model using only 925 points gave a solution with similar precisions as an ordinary finite element solution using hundreds of thousands of nodes. To investigate the limitations of the method, we also applied the SDM to imaginary materials with various strengths of thermal property nonlinearities.
- Published
- 2016
87. Activation of transient receptor potential A1 by a non-pungent capsaicin-like compound, capsiate
- Author
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Makoto Tominaga, Yoshiro Suzuki, Kunitoshi Uchida, Kenji Shintaku, Yiming Zhou, Susumu Yazawa, Tatsuo Watanabe, and Tohru Fushiki
- Subjects
Pharmacology ,Membrane potential ,Chemistry ,TRPV1 ,food and beverages ,Cell biology ,chemistry.chemical_compound ,Transient receptor potential channel ,Biochemistry ,Capsaicin ,Capsinoids ,TRPA1 Cation Channel ,Patch clamp ,Receptor ,psychological phenomena and processes - Abstract
BACKGROUND AND PURPOSE Capsiate is produced by ‘CH-19 Sweet’ (Capsicum annuun L.), a non-pungent cultivar of red pepper. Like capsaicin, capsiate is thought to enhance energy metabolism by activating the sympathetic nervous system and suppressing inflammation, but the underlying mechanisms for this are uncertain. We previously reported that capsiate could activate transient receptor potential vanilloid 1 (TRPV1), a capsaicin receptor. The purpose of the present study is to investigate whether capsinoids activate other TRP channels. EXPERIMENTAL APPROACH Using Ca2+ imaging and whole-cell patch-clamp methods, we analysed the response of TRP channels to three kinds of capsinoids, capsiate, dihydrocapsiate and nordihydrocapsiate, in HEK293T cells expressing TRP channels or in primary cultures of mouse dorsal root ganglion neurons. KEY RESULTS We found that in both cell types TRP ankyrin 1 (TRPA1) had a slightly weaker response to capsinoids compared with TRPV1, with the capsiate EC50 for TRPA1 activation being more than that for TRPV1 activation, and that the capsinoid-evoked action was blocked by a specific TRPA1 antagonist. TRPA1 was activated by capsinoids, but not by their degradation products. Amino acids known to participate in TRPA1 activation following cysteine covalent modification or zinc treatment were not involved in the activation of TRPA1 by capsinoid. CONCLUSIONS AND IMPLICATIONS Taken together, these results indicate that capsinoids activate TRPA1 by an as yet unknown mechanism, and TRPA1 could be involved in physiological phenomena associated with capsinoid treatment.
- Published
- 2012
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88. Impact-damage visualization in CFRP by resistive heating: Development of a new detection method for indentations caused by impact loads
- Author
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Yoshiro Suzuki, Yoshihiro Mizutani, Ryosuke Matsuzaki, and Akira Todoroki
- Subjects
Materials science ,Safety factor ,business.industry ,Structural engineering ,Sensitivity (explosives) ,Reliability (semiconductor) ,Electrical resistance and conductance ,Mechanics of Materials ,Electrical resistivity and conductivity ,Indentation ,Thermography ,Ceramics and Composites ,Composite material ,business ,Joule heating - Abstract
Rapid and automatic inspection of composite aircraft after every flight would reduce the safety factor and allow for more flights. Although, an electrical resistance change method (ERCM) has been proposed, there are many problems with its practical application. In this study, a new diagnostic method, impact-damage visualization, was developed. Indentation damage increases fiber–fiber contact at the interlaminar interface and electrical conductivity. Consequently, electrical current applied to the material will concentrate around the damaged area, and lead to selective and intense resistive heating. This temperature increase can be observed by thermography or detected as a change in electrical resistance caused by the temperature difference. The proposed method had sufficient reliability and sensitivity for practical application as a damage inspection method.
- Published
- 2012
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89. Damage Detection in CFRP without Data from Intact Structures Using Statistical Analysis of Resistance-Temperature Characteristics
- Author
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Ryosuke Matsuzaki, Yoshiro Suzuki, Akira Todoroki, and Yoshihiro Mizutani
- Subjects
Damage detection ,Materials science ,business.industry ,Mechanical Engineering ,Delamination ,Structural engineering ,Smart material ,Electrical contacts ,Electrical resistance and conductance ,Mechanics of Materials ,Electrode ,General Materials Science ,Statistical analysis ,Composite material ,Joule heating ,business - Abstract
The previous study employs delamination detection in CFRP laminates using statistical analysis of temperature characteristic of resistance to prevent electrical resistance changes caused by damages of electrical contact at electrodes. A statistical analysis method discriminates the temperature characteristic of resistance of the damaged structure from that of the intact structure. To detect delaminations without learning processes, a new method which compares the electrical resistances at high temperature with those at low temperature is developed here. The new method has applicability to existing structures and can also detect initial defects. The present study employs the new method for detecting delaminations and initial defects in quasi-isotropic-plied CFRP plates. The detection limit of delamination and the effectiveness of detecting initial defects are experimentally investigated, and the effect of electrode damage on the diagnosis is discussed here.
- Published
- 2011
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90. Heavy metal cations permeate the TRPV6 epithelial cation channel
- Author
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Matthias A. Hediger, Ákos Zsembery, Tamas Danko, Yoshiro Suzuki, Bernadett Balázs, Marc J. Bergeron, and Gergely Kovacs
- Subjects
Cell Membrane Permeability ,Patch-Clamp Techniques ,Time Factors ,TRPV6 ,Physiology ,Recombinant Fusion Proteins ,Inorganic chemistry ,Intracellular Space ,TRPV Cation Channels ,chemistry.chemical_element ,Breast Neoplasms ,Calcium ,Biochemistry ,Calcium in biology ,Divalent ,03 medical and health sciences ,Imaging, Three-Dimensional ,0302 clinical medicine ,Cations ,Cell Line, Tumor ,Metals, Heavy ,Genetics ,Humans ,Patch clamp ,Molecular Biology ,Fluorescent Dyes ,030304 developmental biology ,chemistry.chemical_classification ,Calcium metabolism ,0303 health sciences ,Cadmium ,Calcium channel ,Reproducibility of Results ,Epithelial Cells ,Cell Biology ,Zinc ,HEK293 Cells ,chemistry ,Biophysics ,Female ,Fura-2 ,Ion Channel Gating ,030217 neurology & neurosurgery ,Biotechnology - Abstract
TRPV6 belongs to the vanilloid family of the transient receptor potential channel (TRP) superfamily. This calcium-selective channel is highly expressed in the duodenum and the placenta, being responsible for calcium absorption in the body and fetus. Previous observations have suggested that TRPV6 is not only permeable to calcium but also to other divalent cations in epithelial tissues. In this study, we tested whether TRPV6 is indeed also permeable to cations such as zinc and cadmium. We found that the basal intracellular calcium concentration was higher in HEK293 cells transfected with hTRPV6 than in non-transfected cells, and that this difference almost disappeared in nominally calcium-free solution. Live cell imaging experiments with Fura-2 and NewPort Green DCF showed that overexpression of human TRPV6 increased the permeability for Ca(2+), Ba(2+), Sr(2+), Mn(2+), Zn(2+), Cd(2+), and interestingly also for La(3+) and Gd(3+). These results were confirmed using the patch clamp technique. (45)Ca uptake experiments showed that cadmium, lanthanum and gadolinium were also highly efficient inhibitors of TRPV6-mediated calcium influx at higher micromolar concentrations. Our results suggest that TRPV6 is not only involved in calcium transport but also in the transport of other divalent cations, including heavy metal ions, which may have toxicological implications.
- Published
- 2011
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91. Impact Damage Detection in CFRP Using Statistical Analysis of Resistance-Temperature Characteristics
- Author
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Ryosuke Matsuzaki, Yoshiro Suzuki, Akira Todoroki, and Yoshihiro Mizutani
- Subjects
Carbon fiber reinforced polymer ,Materials science ,Electrical resistance and conductance ,business.industry ,Electrode ,Delamination ,Structural engineering ,Fibre-reinforced plastic ,Composite material ,Strain rate ,Joule heating ,business ,Electrical contacts - Abstract
A new method for detecting delamination cracks in carbon fiber reinforced polymer (CFRP) laminates using changes in electrical resistance was developed in a previous study. It was possible to detect delamination cracks without sampling the data from intact structures and to prevent false diagnoses from changes in electrical resistance caused by damage to the electrical contacts at the electrodes. As a result of the study, delamination of at least 5.3 mm in diameter caused by a quasi-static load in a quasi-isotropic-plied CFRP plate was detectable without sampling the data from intact structures. However, the proposed diagnostic method has not yet been experimentally performed for detecting delaminations subjected to impact loads. Although it is unfortunate that there is not much difference between damage of FRP laminates subjected to low-speed impacts and those subjected to quasi-static loads, broken fibers in the surface layer and plastic deformation such as a dent accompanied by delamination might depend on the rate of strain. It is also necessary to ensure that the diagnostic method provides correct diagnoses even if impact damage of electrical contact occurs at the electrodes. The diagnosis was not affected by chipped electrodes except for through chips. The present study employs the diagnostic method for delamination cracks and damage to electrical contacts of an electrode subjected to falling weight impact loads and dents from quasi-static loads.
- Published
- 2011
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92. Application of deep learning to structure optimization
- Author
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Yoshihiro Mizutani, Yusuke Takahashi, Akira Todoroki, and Yoshiro Suzuki
- Subjects
Computer science ,business.industry ,Deep learning ,Structure (category theory) ,Artificial intelligence ,business - Published
- 2018
- Full Text
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93. Layout optimization of curvilinearly skin/stiffener structure for buckling
- Author
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Ryosuke Matsuzaki, Yoshiyasu Hirano, Koki Sakamoto, Yoshiro Suzuki, and Akira Todoroki
- Subjects
Materials science ,Buckling ,business.industry ,Structure (category theory) ,Structural engineering ,business - Published
- 2018
- Full Text
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94. Proposal of the search method by clustering for the optimized fiber orientation model representing curved fiber CFRP
- Author
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Shun Nakamura, Yoshiro Suzuki, Yoshihiro Mizutani, and Akira Todoroki
- Subjects
Materials science ,Fiber orientation ,Fiber ,Composite material ,Cluster analysis - Published
- 2018
- Full Text
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95. Discrimination between longitudinal wave and transverse wave propagating in solids using by three-axis sensors
- Author
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Akira Todoroki, Yoshiro Suzuki, Yoshihiro Mizutani, and Iori Suzuki
- Subjects
Physics ,Optics ,business.industry ,Transverse wave ,business ,Longitudinal wave - Published
- 2018
- Full Text
- View/download PDF
96. Visualization of the Propagation Behavior of Ultrasonic Waves in 3D-printed CFRP
- Author
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Yoshiro Suzuki, Takeshi Ashizawa, Nobuyuki Toyama, Akira Todoroki, and Yoshihiro Mizutani
- Subjects
3d printed ,Materials science ,Acoustics ,Ultrasonic sensor ,Visualization - Published
- 2018
- Full Text
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97. Analytical and experimental investigations of friction between synthetic fiber ropes and grooved pulleys
- Author
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Yoshiro Suzuki, Gen Endo, Shinichiro Kiyomatsu, Akira Todoroki, and Yoshihiro Mizutani
- Subjects
Synthetic fiber ,business.product_category ,Materials science ,Composite material ,business ,Pulley - Published
- 2018
- Full Text
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98. Multiscale Analysis Using Deep Learning for Steady State Heat Conduction
- Author
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Yoshihiro Mizutani, Yoshiro Suzuki, Akira Todoroki, and Takanori Nishida
- Subjects
Materials science ,Steady state (electronics) ,business.industry ,Deep learning ,Mechanics ,Artificial intelligence ,Thermal conduction ,business - Published
- 2018
- Full Text
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99. Delamination Detection in CFRP Plates Using Statistical Analysis of Change in Temperature Characteristic of Resistance
- Author
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Akira Todoroki, Ryosuke Matsuzaki, Yoshihiro Mizutani, Yoshiro Suzuki, and Kosuke Takahashi
- Subjects
Materials science ,Mechanics of Materials ,Mechanical Engineering ,Delamination ,General Materials Science ,Statistical analysis ,Composite material ,Joule heating ,Smart material - Published
- 2010
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100. Gain-of-function haplotype in the epithelial calcium channel TRPV6 is a risk factor for renal calcium stone formation
- Author
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Andreas Pasch, Felix J. Frey, Olivier Bonny, Yoshiro Suzuki, Markus G. Mohaupt, and Matthias A. Hediger
- Subjects
Adult ,Male ,medicine.medical_specialty ,TRPV6 ,Calcitriol ,Xenopus ,Hypercalciuria ,030232 urology & nephrology ,TRPV Cation Channels ,chemistry.chemical_element ,Parathyroid hormone ,Calcium ,Biology ,Polymorphism, Single Nucleotide ,Kidney Calculi ,03 medical and health sciences ,0302 clinical medicine ,Risk Factors ,Internal medicine ,Animals ,Calcitriol/blood ,Calcium/analysis ,Calcium/blood ,Calcium Channels/genetics ,Calcium Channels/metabolism ,Female ,Haplotypes ,Humans ,Hypercalciuria/genetics ,Hypercalciuria/metabolism ,Kidney Calculi/chemistry ,Kidney Calculi/genetics ,Middle Aged ,Parathyroid Hormone/blood ,TRPV Cation Channels/genetics ,TRPV Cation Channels/metabolism ,Genetics ,medicine ,Molecular Biology ,Genetics (clinical) ,030304 developmental biology ,0303 health sciences ,Voltage-dependent calcium channel ,Calcium channel ,Haplotype ,General Medicine ,medicine.disease ,Endocrinology ,chemistry ,Parathyroid Hormone ,Calcium Channels ,medicine.drug - Abstract
The rate-limiting step of dietary calcium absorption in the intestine requires the brush border calcium entry channel TRPV6. The TRPV6 gene was completely sequenced in 170 renal calcium stone patients. The frequency of an ancestral TRPV6 haplotype consisting of three non-synonymous polymorphisms (C157R, M378V, M681T) was significantly higher (P = 0.039) in calcium stone formers (8.4%; derived = 502, ancestral = 46) compared to non-stone-forming individuals (5.4%; derived = 645, ancestral = 37). Mineral metabolism was investigated on four different calcium regimens: (i) free-choice diet, (ii) low calcium diet, (iii) fasting and (iv) after a 1 g oral calcium load. When patients homozygous for the derived haplotype were compared with heterozygous patients, no differences were found with respect to the plasma concentrations of 1,25-vitamin D, PTH and calcium, and the urinary excretion of calcium. In one stone-forming patient, the ancestral haplotype was found to be homozygous. This patient had absorptive hypercalciuria. We therefore expressed the ancestral protein (157R+378V+681T) in Xenopus oocytes and found a significantly enhanced calcium permeability when tested by a (45)Ca(2+) uptake assay (7.11 +/- 1.93 versus 3.61 +/- 1.01 pmol/min/oocyte for ancestral versus derived haplotype, P < 0.01). These results suggest that the ancestral gain-of-function haplotype in TRPV6 plays a role in calcium stone formation in certain forms of absorptive hypercalciuria.
- Published
- 2008
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