288 results on '"Kazuo Nakamura"'
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2. UNEXPLODED ORDINANCE CLEARANCE IN NAM NGIEP 1 HYDROPOWER PROJECT
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Shoji Tsutsui, Kenichi Tomioka, Kazuo Nakamura, and Ryosuke Tanaka
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business.industry ,Environmental science ,business ,Water resource management ,Hydropower - Published
- 2020
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3. Compact integrated magnetometer based on nitrogen-vacancy centres in diamond
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Tino Fuchs, Felix M. Stürner, Uwe Wostradowski, Kazuo Nakamura, Hitoshi Sumiya, Robert Rölver, Shinobu Onoda, Junichi Isoya, Julian Kassel, Andreas Brenneis, and Fedor Jelezko
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Time delay and integration ,Photon ,Materials science ,Magnetometer ,02 engineering and technology ,engineering.material ,010402 general chemistry ,01 natural sciences ,Noise (electronics) ,law.invention ,law ,Materials Chemistry ,Electrical and Electronic Engineering ,business.industry ,Mechanical Engineering ,Diamond ,General Chemistry ,021001 nanoscience & nanotechnology ,Laser ,0104 chemical sciences ,Electronic, Optical and Magnetic Materials ,Magnetic field ,engineering ,Optoelectronics ,0210 nano-technology ,business ,Excitation - Abstract
We demonstrate an integrated and miniaturised magnetic field sensor based on the negatively charged nitrogen-vacancy centres (NV−) in diamond. The compact device includes all optical components, both for the optical excitation path and for the detection of the emitted fluorescence signal. We experimentally verify that it enables optically detected magnetic resonance (ODMR) measurements and we specify noise and sensitivity of the magnetometer. The minimal detectable magnetic field of the device is ≈ 1 μT for a given integration time of 1 ms, which is approximately one order of magnitude larger than its photon shot-noise limit. It has the significant advantage over traditional setups using NV− centres (including a laser and a complex optical system) that the specific construction volume is about 2.9 cm3 with a total power consumption of ≈ 1.5 W, which enables the device for a wide range of industrial sensing applications.
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- 2019
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4. Novel Magnetic-Sensing Modalities with Nitrogen-Vacancy Centers in Diamond*
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Hitoshi Sumiya, Dmitry Budker, Victor M. Acosta, Geoffrey Z. Iwata, Zhiyin Sun, Takeshi Ohshima, Chen Zhang, Georgios Chatzidrosos, Nathan Leefer, Huijie Zheng, Jörg Wrachtrup, S. Afach, Kazuo Nakamura, Jingyan Xu, Andrey Jarmola, Lykourgos Bougas, Arne Wickenbrock, Junichi Isoya, and Till Lenz
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Materials science ,business.industry ,InformationSystems_INFORMATIONSTORAGEANDRETRIEVAL ,chemistry.chemical_element ,Diamond ,02 engineering and technology ,engineering.material ,021001 nanoscience & nanotechnology ,01 natural sciences ,Magnetic sensing ,Nitrogen ,chemistry ,Vacancy defect ,0103 physical sciences ,engineering ,Optoelectronics ,010306 general physics ,0210 nano-technology ,business ,GeneralLiterature_REFERENCE(e.g.,dictionaries,encyclopedias,glossaries) - Abstract
In modern-day quantum metrology, quantum sensors are widely employed to detect weak magnetic fields or nanoscale signals. Quantum devices, exploiting quantum coherence, are inevitably connected to physical constants and can achieve accuracy, repeatability, and precision approaching fundamental limits. As a result, these sensors have shown utility in a wide range of research domains spanning both science and technology. A rapidly emerging quantum sensing platform employs atomic-scale defects in crystals. In particular, magnetometry using nitrogen-vacancy (NV) color centers in diamond has garnered increasing interest. NV systems possess a combination of remarkable properties, optical addressability, long coherence times, and biocompatibility. Sensors based on NV centers excel in spatial resolution and magnetic sensitivity. These diamond-based sensors promise comparable combination of high spatial resolution and magnetic sensitivity without cryogenic operation. The above properties of NV magnetometers promise increasingly integrated quantum measurement technology, as a result, they have been extensively developed with various protocols and find use in numerous applications spanning materials characterization, nuclear magnetic resonance (NMR), condensed matter physics, paleomagnetism, neuroscience and living systems biology, and industrial vector magnetometry. In this chapter, NV centers are explored for magnetic sensing in a number of contexts. In general, we introduce novel regimes for magnetic-field probes with NV ensembles. Specifically, NV centers are developed for sensitive magnetometers for applications where microwaves (MWs) are prohibitively invasive and operations need to be carried out under zero ambient magnetic field. The primary goal of our discussion is to improve the utility of these NV center-based magnetometers.
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- 2021
5. Development of a Highly Efficient SOFC Module Using Two-stage Stacks and a Fuel Regeneration Process
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Tatsuki Dohkoh, Shirai Marie, Kume Takao, Takaaki Somekawa, Y. Ikeda, Taku Shumpei, Takahiro Ide, Nakajima Tatsuya, Kazuo Nakamura, Kei Ogasawara, Takuto Kushi, and Kenjiro Fujita
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Materials science ,Renewable Energy, Sustainability and the Environment ,business.industry ,020209 energy ,Energy Engineering and Power Technology ,Surface condenser ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Anode ,Steam reforming ,Brake specific fuel consumption ,Electricity generation ,0202 electrical engineering, electronic engineering, information engineering ,Inverter ,Heat of combustion ,Solid oxide fuel cell ,0210 nano-technology ,Process engineering ,business - Abstract
A solid oxide fuel cell (SOFC) module using two-stage stacks and a fuel regeneration process between them was developed in this study for the first time, to the best of the authors' knowledge. Upon configuring the first-stage and second-stage stacks and a steam reformer between them in the SOFC module, a gross output power of DC 2.27 kW was generated with gross power generation efficiency of DC 69.2% (lower heating value (LHV)), at a total fuel utilization rate of 86.3%. This technology enables operation at a very high total fuel utilization rate even while operating the stacks at a moderate fuel utilization rate (below 70%). Considering an auxiliary device loss (6%) and inverter loss (5%), the net power generation efficiency is estimated to be AC 61.8% (LHV); hence, the module is considered to exhibit a high power generation efficiency. Further increases in the power generation efficiency could be realized in the future by removing the CO2 from the anode off-gas during the fuel regeneration process and/or operating the stacks at higher temperatures by decreasing heat leakage from the module.
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- 2017
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6. Examination of a high-efficiency solid oxide fuel cell system that reuses exhaust gas
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Takuto Kushi, Kazuo Nakamura, Hisataka Yakabe, Kume Takao, Kenjiro Fujita, and Takaaki Somekawa
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Engineering ,Waste management ,business.industry ,020209 energy ,Energy Engineering and Power Technology ,Exhaust gas ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Industrial and Manufacturing Engineering ,Electricity generation ,Stack (abstract data type) ,Thermal insulation ,0202 electrical engineering, electronic engineering, information engineering ,Solid oxide fuel cell ,0210 nano-technology ,Process engineering ,business ,Regenerative fuel cell ,Condenser (heat transfer) ,Electrical efficiency - Abstract
Enhancing the power generation efficiency, which is the main advantage of solid oxide fuel cells (SOFCs), can have valuable benefits to introduce SOFC systems into business and industrial markets of Japan, where power demands are higher than thermal demands. In this study, we examined a high-efficiency SOFC system with an off-gas regenerating technique. A two-stage SOFC stack configuration was employed. For off-gas regeneration, we used a CO2 absorber and a H2O condenser. A total of 92.0% of the fuel was successfully used with an electrical efficiency of 77.8% (DC, LHV). However, there existed the heat loss from the fuel cell system due to the thermal insulation performance. To compensate the heat loss, additional electric heaters were used to keep temperatures high, therefore heat sustainability remained an issue.
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- 2017
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7. Principle Demonstration of Fuel Cell System with CO2 Capture
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Yasuharu Kawabata, Nakajima Tatsuya, Akabane Shunnosuke, Kazuo Nakamura, Tatsuki Dohkoh, Marie Tsuji, Takahiro Ide, and Toru Hatae
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chemistry.chemical_compound ,Electricity generation ,Membrane ,Materials science ,chemistry ,Recovery rate ,business.industry ,Carbon dioxide ,Fuel cells ,Solid oxide fuel cell ,Power output ,Process engineering ,business - Abstract
Recently, the desire of decarbonization is increasing on the part of the general public worldwide as many companies take part in RE100 initiative. Tokyo Gas Co., Ltd. declared to reduce 10 million tons carbon dioxide emission by 2030 in “Compass 2030” which is company vision of Tokyo Gas group in November 27th, 2019. We drive CO2 net-zero including emission from customer and lead the transition to a decarbonized society. To achieve CO2 net-zero, we will take two actions. The first one is expansion of use of renewable energy. Second is development of decarbonization technologies for gaseous energy, which include effective use of natural gas, use of carbon capture, utilization and storage (CCUS). Fuel cell system is expected to use natural gas effectively. In Japan, residential fuel cell system has already installed extensively since the first model was sold in 2009. Tokyo Gas have also studied fuel cell technologies for over three decades. These days, we developed and reported mono generation system which had AC-power generation efficiency of over 65.0%LHV and output of 5kW. In this system, anode lines of solid oxide fuel cell (SOFC) stacks are connected in series. A fuel regenerator is placed between two-stage SOFC stacks, which remove H2O from the anode off-gas of first-stage SOFC stack. Then, the regenerated anode off-gas is used as a fuel of the second-stage SOFC stack. Hence, this system can be operated at high total fuel utilization (Uf) value of over 90% and enable each SOFC stack to be operated at safe Uf condition for each, simultaneously. We could make easy flow system by using condenser as fuel regenerator. This system can reduce much CO2 than existing power resource because of its higher efficiency, but still exhausts some amount of CO2 gas. To achieve decarbonized society, further reduction of CO2 emission for fuel cell system will be required. Therefore, we focused on CO2 separation membrane as a fuel regenerator which has high selectivity for both H2O and CO2. In previous work, we performed DC-power generation of 75.5%LHV by connecting membrane module as the fuel regenerator of the two-stage SOFC system. CO2 recovery rate from membrane reached to about 40%. To improve the CO2 recovery rate, we invent the new system as figure 1. The new system recycles regenerated anode off-gas which was removed H2O and CO2 by CO2 separation membrane. The membrane has high selectivity of H2O and CO2. In addition, a separation at the membrane was driven on the differential pressure by decompressing without sweep gas. As a result, high concentration of CO2 was recovered. In ideal situation, the new system will be operated under Uf of 100% and recovered CO2 of 100%. In this study, we demonstrated this system as shown in figure 1. Membrane was put in fuel cell module. It was operated at a total Uf of 97.1%, and power generation efficiency reached DC 77.3%LHV at power output of 5.65 kW under the thermal self-sustainable condition without the electric heater. Assuming the efficiencies of the auxiliary machines and the power conditioner to be respectively 94% and 95%, the estimated AC-power generation efficiency of the hot module was 69.0%LHV and CO2 emission factor reached to 294 g-CO2/kWh. At the same time, CO2 recovery rate was 85%. We achieved high efficiency and low in this system. In the future, we have to discuss about the use of recovery CO2. Figure 1
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- 2021
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8. Integrated and Portable Magnetometer Based on Nitrogen‐Vacancy Ensembles in Diamond
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Andreas Brenneis, Jens Grimmel, Hitoshi Sumiya, Dieter Suter, Kazuo Nakamura, Michael Förtsch, Felix M. Stürner, Tino Fuchs, Stefan Hengesbach, Robert Rölver, Julian Kassel, Thomas Buck, Shinobu Onoda, Fedor Jelezko, Junichi Isoya, and Anton Savitsky
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Nuclear and High Energy Physics ,Materials science ,business.industry ,Magnetometer ,Quantum sensor ,Diamond ,Statistical and Nonlinear Physics ,engineering.material ,Condensed Matter Physics ,Electronic, Optical and Magnetic Materials ,Magnetic field ,law.invention ,Quantum technology ,Computational Theory and Mathematics ,law ,Power consumption ,Vacancy defect ,engineering ,Optoelectronics ,Sensitivity (control systems) ,Electrical and Electronic Engineering ,business ,Mathematical Physics - Abstract
Magnetic field sensors that exploit quantum effects have shown that they can outperform classical sensors in terms of sensitivity enabling a range of novel applications in future, such as a brain machine interface. Negatively charged nitrogen‐vacancy (NV) centers in diamond have emerged as a promising high sensitivity platform for measuring magnetic fields at room temperature. Transferring this technology from laboratory setups into products and applications, the total size of the sensor, the overall power consumption, and the costs need to be reduced and optimized. Here, a fiber‐based NV magnetometer featuring a complete integration of all functional components is demonstrated without using any bulky laboratory equipment. This integrated prototype allows portable measurement of magnetic fields with a sensitivity of 344 pT Hz−1/2.
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- 2021
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9. Current status and prospect of plasma control system for steady-state operation on QUEST
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Yoshihiko Nagashima, Shoji Kawasaki, Hiroshi Idei, Kazuaki Hanada, Makoto Hasegawa, Kazuo Nakamura, Hisatoshi Nakashima, Kazutoshi Tokunaga, A. Higashijima, Akihide Fujisawa, and Hideki Zushi
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010302 applied physics ,Steady state (electronics) ,business.industry ,Computer science ,Mechanical Engineering ,Electrical engineering ,Plasma ,01 natural sciences ,Signal ,010305 fluids & plasmas ,Power (physics) ,Identification (information) ,Nuclear Energy and Engineering ,Filter (video) ,Control system ,0103 physical sciences ,General Materials Science ,Hall effect sensor ,business ,Civil and Structural Engineering - Abstract
The plasma control system (PCS) of QUEST is developed according to the progress of QUEST project. Since one of the critical goals of the project is to achieve the steady-state operation with high temperature vacuum vessel wall, the PCS is also required to have the capability to control the plasma for a long period. For the increase of the loads to processing power of the PCS, the PCS is decentralized with the use of reflective memories (RFMs). The PCS controls the plasma edge position with the real-time identification of plasma current and its position. This identification is done with not only flux loops but also hall sensors. The gas fueling method by piezo valve with monitoring the Hα signal filtered by a digital low-pass filter are proposed and suitable for the steady-state operation on QUEST. The present status and prospect of the PCS are presented with recent topics.
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- 2016
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10. Proposal of ultra-high-efficiency zero-emission power generation systems
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Kazunari Sasaki, Shunsuke Taniguchi, Yoshio Matsuzaki, Yuya Tachikawa, Toru Hatae, Nakajima Tatsuya, Kazuo Nakamura, and Kawabata Yasuharu
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Renewable Energy, Sustainability and the Environment ,business.industry ,Fossil fuel ,Energy Engineering and Power Technology ,Bio-energy with carbon capture and storage ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Electricity generation ,Biogas ,Natural gas ,Protonic ceramic fuel cell ,Environmental science ,Solid oxide fuel cell ,Electrical and Electronic Engineering ,Physical and Theoretical Chemistry ,0210 nano-technology ,business ,Process engineering ,Zero emission - Abstract
Solid oxide fuel cell (SOFC) and protonic ceramic fuel cell (PCFC) have strong features that enables high efficiency power generation and efficient CO2 capture. Applying these technologies to the fossil fuel and biomass power generation, we can realize ultra-high efficiency zero-emission power generation by capturing liquefied CO2 (LCO2) for easy transport and utilization (CCU) or storage(fossil fuel CCS and bio-energy CCS: BECCS). In this study, we propose LCO2 capture ultra-efficient power generation systems consist of multi-stage SOFC/PCFC, oxygen or hydrogen transport membrane, CO2 cooling and liquidizing units driven by exhaust heat and generated power by fuel cells. Net power generation efficiency is estimated through heat mass balance analysis. As the results for natural gas, proposed PCFC system is suitable and expected 64.7 %LHV net power generation efficiency with more than 99 vol% LCO2 capture. For biogas direct supply case, net power generation efficiency of proposed PCFC system is 57%LHV with 99 vol% capture of CO2 in the air. These results indicates that proposed systems have quite strong potential that enables ultra-high efficient CO2-free fossil fuel power generation with CCS and CO2-reduction biomass fuel power generation with BECCS.
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- 2020
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11. Prototype of a Quasi-Optical Launcher System of a 4 mm Round-Trip Interferometer for the QUEST Spherical Tokamak Experiments
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Takumi Onchi, Hiroshi Idei, Daichi Ogata, Kazuo Nakamura, Miu Yunoki, Masaharu Fukuyama, Masayuki Yoshikawa, Ryuya Ikezoe, and Ryuichi Ashida
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Physics ,Interferometry ,Optics ,business.industry ,Spherical tokamak ,Condensed Matter Physics ,business - Abstract
A launcher system for a round-trip interferometer, with a corrugated horn antenna and two quasi-optical mirrors, has been developed for the QUEST spherical tokamak experiment. The corrugated horn antenna has been designed using a three-dimensional (3D) electromagnetic simulator. At low power bench test, intensity and phase profiles at 0.1 m from antenna aperture show coaxial patterns as predicted by the 3D simulator, in agreement with the calculation results using an in-house developed Kirchhoff integral code. The designed waist sizes of the focused beam at a target position are 22 mm in the horizontal x direction and 43 mm in the vertical y direction. The beam reaches the target plate at QUEST's center-post and is reflected back along the line-of-sight round-trip. A well-focused beam of 32 and 36 mm in size (x, y) has been obtained at the target position. The HE11 mode excitation, beam transmission, and focusing properties are discussed for the prototype launcher system.
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- 2019
12. Long-life Gear Oils for Electric Railway Trains
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Mitsugu Kudo, Yasutomo Sone, Masatoshi Toda, Junichi Suzumura, Sadayuki Kikawa, and Kazuo Nakamura
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Engineering ,business.product_category ,Petroleum engineering ,business.industry ,Mechanical Engineering ,Base oil ,Oxidation test ,Automotive engineering ,Electric train ,Viscosity ,medicine ,Train ,Gear oil ,business ,Mineral oil ,human activities ,health care economics and organizations ,Synthetic crude ,medicine.drug - Abstract
A long-life gear oil for electric railway trains was developed to reduce the workload and cost of gear unit maintenance. A semi-synthetic base oil, a mixture of polyalphaolefin (PAO) and highly purified mineral oil, was used in the developed gear oil in order to improve high temperature oxidation stability. The composition of additives was also modified to enhance oxidation stability. In an accelerated oxidation test (Indiana stirring oxidation test at 135 ℃/96 hours), the developed gear oil demonstrated sufficient oxidation stability to enable an electric train to run 1,200,000 km without an oil change. Reliability at low temperatures was also shown to be better compared with existing gear oils, because the viscosity at low temperatures and the pour-point was reduced by virtue of the semi-synthetic base oil.
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- 2014
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13. Late onset GM2gangliosidosis presenting with motor neuron disease: An autopsy case
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Emiko Horiuchi, Rei Kawashima, Kazuo Nakamura, Seigo Nakamura, Miyako Ishiyama, Teruo Yokoyama, Kazuko Hasegawa, and Saburo Yagishita
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Nervous system ,Weakness ,Pathology ,medicine.medical_specialty ,Cerebellar ataxia ,business.industry ,Muscle weakness ,Autopsy ,General Medicine ,Gangliosidosis ,Motor neuron ,medicine.disease ,Pathology and Forensic Medicine ,medicine.anatomical_structure ,Atrophy ,nervous system ,medicine ,Neurology (clinical) ,medicine.symptom ,business - Abstract
Adult-onset GM2 gangliosidosis is very rare and only three autopsy cases have been reported up to now. We report herein an autopsy case of adult-onset GM2 gangliosidosis. The patient developed slowly progressive motor neuron disease-like symptoms after longstanding mood disorder and cognitive dysfunction. He developed gait disturbance and weakness of lower limbs at age 52 years. Because of progressive muscle weakness and atrophy, he became bed-ridden at age 65. At age of 68, he died. His neurological findings presented slight cognitive disturbance, slight manic state, severe muscle weakness, atrophy of four limbs and no extrapyramidal signs and symptoms, and cerebellar ataxia. Neuropathologically, mild neuronal loss and abundant lipid deposits were noted in the neuronal cytoplasm throughout the nervous system, including peripheral autonomic neurons. The most outstanding findings were marked neuronal loss and distended neurons in the anterior horn of the spinal cord, which supports his clinical symptomatology of lower motor neuron disease in this case. The presence of lipofuscin, zebra bodies and membranous cytoplasmic bodies (MCB) and the increase of GM2 ganglioside by biochemistry led to diagnosis of GM2 gangliosidosis.
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- 2013
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14. Factors involved in the cisplatin resistance of KCP-4 human epidermoid carcinoma cells
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Naoko Matsunaga, Asuka Yamamura, Ryuji Ikeda, Chie Motooka, Hiroko Kariyazono, Yasuo Takeda, Rie Nakazaki, Yui Takayama, Shigeru Oiso, and Kazuo Nakamura
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Cancer Research ,Cell ,Antineoplastic Agents ,medicine.disease_cause ,Cell Line, Tumor ,medicine ,Humans ,RNA, Messenger ,Cisplatin ,Mutation ,Base Sequence ,Oncogene ,business.industry ,NF-kappa B ,Sequence Analysis, DNA ,General Medicine ,Cell cycle ,Enzyme Activation ,medicine.anatomical_structure ,Oncology ,Epidermoid carcinoma ,Drug Resistance, Neoplasm ,Cell culture ,Immunology ,Carcinoma, Squamous Cell ,Cancer research ,ATP-Binding Cassette Transporters ,Efflux ,Multidrug Resistance-Associated Proteins ,Tumor Suppressor Protein p53 ,business ,ATP Binding Cassette Transporter 1 ,medicine.drug - Abstract
KCP-4 is a cisplatin-resistant cell line established from human epidermoid carcinoma KB-3-1 cells. Although our previous study revealed that one of the mechanisms for cisplatin resistance in KCP-4 cells is the activation of NF-κB, its high resistance is considered to be induced by multiple mechanisms. In the present study, we explored other factors involved in the development of cisplatin resistance in KCP-4 cells. Since it has been reported that an unknown efflux pump exports cisplatin from KCP-4 cells in an ATP-dependent manner, we examined 48 types of ATP-binding cassette proteins as candidate cisplatin efflux transporters. The mRNA expression levels of ABCA1, ABCA3, ABCA7 and ABCB10 in KCP-4 cells were higher when compared to those in KB-3-1 cells. These expression levels in cisplatin-sensitive revertant KCP-4 cells (KCP-4R cells), were reduced in parallel with the sensitivity of these cells to cisplatin and their intracellular accumulation of cisplatin. Next, we investigated the occurrence of mutations in p53 in KCP-4 cells. We found a heterozygous missense mutation at codon 72 (p.Pro72Arg) in p53 of both KCP-4 and KB-3-1 cells, but the protein expression level of p53 in KCP-4 cells was higher when compared to that in KB-3-1. These results suggest that ABCA1, ABCA3, ABCA7 and ABCB10 are candidate genes for the cisplatin efflux transporter that is involved in the cisplatin resistance of KCP-4 cells, and that the mutation at codon 72 of p53 may contribute to the development of cisplatin resistance.
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- 2013
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15. Multimodal Assessment of Durability and Reliabilityof Flattened Tubular SIS Stacks
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Katsuhiko Yamaji, Toshiaki Matsui, Haruo Kishimoto, Shunsuke Taniguchi, Toshiyuki Hashida, Kazuhisa Sato, Kazuo Nakamura, Kenjiro Fujita, Satoshi Watanabe, Yoshio Matsuzaki, Kazunari Sasaki, Teruhisa Horita, Masahiro Yoshikawa, Takaaki Somekawa, Yoshihiro Mugikura, Tohru Yamamoto, Naoki Shikazono, Harumi Yokokawa, Koichi Eguchi, and Tatsuya Kawada
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Engineering ,Electricity generation ,Reliability (semiconductor) ,business.industry ,Electric furnaces ,Electric power industry ,business ,Durability ,Engineering physics - Abstract
The durability and reliability of segmented-in-series (SIS) type cells-stack was investigated by multimodal assessment in which Tokyo Gas collaborated with research institutes under NEDO project, “Development of system and elemental technology on SOFCs”. The SIS cells-stack, developed by Tokyo Gas in cooperation with Kyocera, has many advantages such as reduced temperature operation, high-voltage / low-current power generation, and lower in material cost of electrical insulating substrate compared to Ni based substrates for anode-supported cells. Another key advantage is that there is no need for alloy interconnects. This would make the cell-stack more durable than other types of cell-stacks having metallic interconnects. Durability of the stacks was investigated by the operations in electric furnaces at Tokyo Gas, Central Research Institute of Electric Power Industry (CRIEPI), and Kyushu University. After the operations post analyses were conducted by the research institutes, such as National Institute of Advanced Industrial Science and Technology (AIST), Tohoku University, Kyoto University, The University Tokyo, and Kyushu University. Through the multimodal assessment durability and reliability of the SIS stacks for long-term operation and thermal cycles have been shown to be high enough for 40,000 h life and more.
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- 2013
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16. Proposal for Grease Replacement System for Traction Motor Bearings
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Kazuo Nakamura, Tetsuya Hosoya, and Sumiko Hibino
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Engineering ,business.industry ,Mechanical Engineering ,Grease ,Service life ,Traction (engineering) ,Lubrication ,Tribology ,Lubricant ,business ,Automotive engineering ,Traction motor - Abstract
Since replacing the lubricants used on traction motor bearings of railroad vehicles is a difficult and time-consuming task, extending the lifespan of the lubricant would be a useful development. Although an interim greasing method has been adopted as a way to extend the lifespan of lubricant for some types of induction traction motors, this method requires leaving empty space to refill additional grease. However, this empty space can mean that there is insufficient lubrication during the initial stages of motor operation. This paper presents a new mechanism that enables the refilling of grease without the empty space. The new method allows the deteriorated grease to be flushed out and replaced with fresh grease without the need to leave unfilled space adjacent to the bearings. Tests suggest that the lubrication lifetime is maximized when the greasing operation is performed about one-quarter of the way through the standard lubrication lifetime. Full-scale bench tests show that the new greasing mechanism and optimal greasing periodicity significantly extended the lubrication lifespan.
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- 2012
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17. Regulation of advanced glycation end product (AGE)-receptor (RAGE) system by PPAR-gamma agonists and its implication in cardiovascular disease
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Sho-ichi Yamagishi, Kazuo Nakamura, and Takanori Matsui
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Glycation End Products, Advanced ,medicine.medical_specialty ,Heart Diseases ,Receptor for Advanced Glycation End Products ,Peroxisome proliferator-activated receptor ,medicine.disease_cause ,RAGE (receptor) ,Diabetes Complications ,Pathogenesis ,chemistry.chemical_compound ,Glycation ,Diabetes mellitus ,Internal medicine ,Animals ,Humans ,Medicine ,cardiovascular diseases ,Receptors, Immunologic ,Receptor ,Pharmacology ,chemistry.chemical_classification ,business.industry ,Intracellular Signaling Peptides and Proteins ,medicine.disease ,PPAR gamma ,Endocrinology ,chemistry ,Cardiovascular Diseases ,Chronic Disease ,Advanced glycation end-product ,Kidney Diseases ,business ,Oxidative stress - Abstract
Non-enzymatic modification of proteins by reducing sugars leads to the formation of advanced glycation end products (AGEs), whose process has been reported to progress under physiological aging, oxidative stress or diabetic conditions. There is a growing body of evidence that AGEs and their receptor (RAGE) axis is involved in the pathogenesis of cardiovascular disease (CVD). Indeed, engagement of RAGE with AGEs is shown to elicit oxidative stress generation and subsequently evoke inflammatory and thrombogenic responses in various types of cells, including endothelial cells, smooth muscle cells, macrophages and renal cells, thus playing an important role in the development and progression of vascular injury in both diabetes and non-diabetes. These observations suggest that the inhibition of AGE formation, down-regulation of RAGE expression or blockade of the RAGE downstream signaling may be a promising therapeutic target for preventing CVD. Recently, peroxisome proliferator-activated receptor-gamma (PPARgamma) is involved in not only adipocyte differentiation, but also vascular homeostasis. Therefore, in this study, we review effects of PPARgamma agonists on the AGE-RAGE system and their implication in CVD.
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- 2009
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18. Gender and Age Classification Based on Pattern of Human Motion Using Choquet Integral Agent Networks
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Shusaku Nomura, Kazuo Nakamura, and Santoso H
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Human-Computer Interaction ,Age and gender ,Choquet integral ,Artificial Intelligence ,Computer science ,business.industry ,ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION ,Computer Vision and Pattern Recognition ,Artificial intelligence ,Competitive learning algorithm ,business ,Human motion - Abstract
Automated human identification from their walking behavior is a challenge attracting much interest among machine vision researchers. However, the systems which are able to detect pedestrian attributes based on their walking behavior remain to be developed. Here, a soft computing approach to determine walking behavior based on motion imagery is studied as the basis for developing pedestrian safety information systems. Gender and age are classified based on motion pattern derived in experiments. At the front end, image and video processing was performed to separate foreground from background images. The widths of silhouette were analyzed using two-dimensional (2D) Fourier transformation to extract human motion features. Feature sub-sets were then selected to find salient, effective classification features. Finally, Choquet integral agent networks (CHIAN) with a competitive learning algorithm were employed to classify gender and age into its classes. The experimental results demonstrated capability of the proposed system to classify gender and age in highly accurately.
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- 2009
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19. Atheroprotective Properties of Pigment Epithelium-Derived Factor (PEDF) in Cardiometabolic Disorders
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Takanori Matsui, Kazuo Nakamura, and Sho-ichi Yamagishi
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medicine.medical_specialty ,Disease ,medicine.disease_cause ,Drug Delivery Systems ,PEDF ,Risk Factors ,Internal medicine ,Drug Discovery ,medicine ,Animals ,Humans ,Platelet ,Nerve Growth Factors ,Eye Proteins ,Serpins ,Pharmacology ,Neointimal hyperplasia ,Vascular disease ,business.industry ,Atherosclerosis ,medicine.disease ,Thrombosis ,Rats ,Disease Models, Animal ,Oxidative Stress ,Endocrinology ,Cardiovascular Diseases ,Cancer research ,Metabolic syndrome ,business ,Angioplasty, Balloon ,Oxidative stress - Abstract
Although remarkable therapeutic advances in the treatment of cardiometabolic disorders have been made with current therapeutic options, cardiovascular disease (CVD) is still a leading cause of mortality and morbidity in the Western world. Therefore, to develop a novel therapeutic strategy is needed for the prevention of cardiovascular disease (CVD) in high-risk patients for atherosclerosis. Recently, we, along with others, have shown that pigment epithelium-derived factor (PEDF), a glycoprotein with potent neuronal differentiating activity, exerts anti-oxidative and anti-inflammatory properties in vascular wall cells, leukocytes and platelets. In addition, PEDF not only suppresses neointimal hyperplasia after balloon angioplasty, but also blocks occlusive thrombus formation in a rat arterial thrombosis model. These observations suggest that substitution of PEDF may be a novel therapeutic strategy for atherosclerosis. This article summarizes the pathophysiological role of PEDF in atherosclerosis and its potential therapeutic implication in this devastating disorder. We also discuss here the kinetics and regulation of PEDF in cardiometabolic disorders in humans.
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- 2009
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20. Physical Design and Future Plan of QUEST
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Takashi Maekawa, Hiroshi Idei, Mizuki Sakamoto, Hideki Zushi, Kazuo Nakamura, Makoto Hasegawa, Kohnosuke Sato, Y. Takase, Osamu Mitarai, and Kazuaki Hanada
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Engineering ,business.industry ,Divertor ,Mechanical engineering ,Plan (drawing) ,Electrical and Electronic Engineering ,Spherical tokamak ,Physical design ,business - Published
- 2009
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21. Atorvastatin Inhibits Advanced Glycation End Products (AGE)-Induced C-Reactive Expression in Hepatoma Cells by Suppressing Reactive Oxygen Species Generation
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Michio Sata, Tsutomu Imaizumi, Teruhiko Makino, Sho-ichi Yamagishi, Tadamichi Shimizu, Kazuo Nakamura, Takanori Matsui, Takafumi Yoshida, and Masayoshi Takeuchi
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Biochemistry ,Epidemiology ,Glycation ,business.industry ,Atorvastatin ,Reactive oxygen species generation ,Medicine ,Cardiology and Cardiovascular Medicine ,business ,medicine.drug - Published
- 2008
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22. Pigment Epithelium-Derived Factor (PEDF): Its Potential Therapeutic Implication in Diabetic Vascular Complications
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Kazuo Nakamura, Takanori Matsui, Sho-ichi Yamagishi, Tsutomu Imaizumi, So Ueda, and Yoshihiro Noda
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medicine.medical_specialty ,Clinical Biochemistry ,Bioinformatics ,Neuroprotection ,PEDF ,Diabetic Neuropathies ,Internal medicine ,Diabetes mellitus ,Drug Discovery ,medicine ,Animals ,Humans ,Diabetic Nephropathies ,Nerve Growth Factors ,PIGMENT EPITHELIUM-DERIVED FACTOR ,Diabetic Vascular Complications ,Eye Proteins ,Serpins ,Pharmacology ,Diabetic Retinopathy ,biology ,business.industry ,Atherosclerosis ,medicine.disease ,Pathophysiology ,Endocrinology ,Blood pressure ,biology.protein ,Molecular Medicine ,business ,Diabetic Angiopathies ,Neurotrophin - Abstract
Diabetic micro- and macroangiopathies are leading causes of acquired blindness, end-stage renal failure and accelerated atherosclerosis, which could account for disabilities and high mortality rates in patients with diabetes. Recent large landmark clinical studies have shown that intensive control of blood glucose or blood pressure (BP) reduces the risk for vascular complications in diabetes. However, the strict control of blood glucose or BP is often difficult to maintain, and current therapeutic options are far from satisfactory. Therefore, to develop novel therapeutic strategies that specifically target vascular complications in diabetes may be actually desired for most patients with diabetes. Pigment epithelium-derived factor (PEDF) is a glycoprotein that belongs to the superfamily of serine protease inhibitors with complex neurotrophic, neuroprotective, anti-angiogenic, anti-oxidative, and anti-inflammatory properties, any of which could potentially be exploited as a therapeutic option for the treatment of vascular complications in diabetes. This article summarizes the pathophysiological role of PEDF for vascular complication in diabetes and its potential therapeutic implication in this devastating disorder.
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- 2008
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23. Inhibitors of Advanced Glycation End Products (AGEs): Potential Utility for the Treatment of Cardiovascular Disease
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So Ueda, Takanori Matsui, Kazuo Nakamura, Tsutomu Imaizumi, Sho-ichi Yamagishi, and Yoshihiro Noda
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Pharmacology ,medicine.medical_specialty ,business.industry ,High mortality ,Disease ,medicine.disease ,medicine.disease_cause ,Pathogenesis ,Endocrinology ,Glycation ,Internal medicine ,Diabetes mellitus ,medicine ,Diabetic Vascular Complications ,Cardiology and Cardiovascular Medicine ,business ,Stroke ,Oxidative stress - Abstract
Accelerated atherosclerosis and microvascular complications are the leading causes of coronary heart disease, stroke, blindness, and end-stage renal failure, which could account for disabilities and high mortality rates in patients with diabetes. Recent clinical studies have substantiated the concept of "hyperglycemic memory" in the pathogenesis of cardiovascular disease (CVD) in diabetes. Indeed, the Diabetes Control and Complications Trial-Epidemiology of Diabetes Interventions and Complications (DCCT-EDIC) Research, has revealed that intensive therapy during the DCCT reduces the risk of cardiovascular events by about 50% in type 1 diabetic patients 11 years after the end of the trial. Among various biochemical pathways activated under diabetic conditions, the process of formation and accumulation of advanced glycation end products (AGEs) and their mode of action are most compatible with the theory "hyperglycemic memory." Further, there is a growing body of evidence that AGEs play an important role in CVD in diabetes. These observations suggest that the inhibition of AGEs formation may be a promising target for therapeutic intervention in diabetic vascular complications. Therefore, in this article, we review several agents with inhibitory effects on AGEs formation and their therapeutic implications in CVD in diabetes.
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- 2008
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24. Agents that block advanced glycation end product (AGE)-RAGE (receptor for AGEs)-oxidative stress system: a novel therapeutic strategy for diabetic vascular complications
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Seiji Ueda, Kei Fukami, Seiya Okuda, Takanori Matsui, Kazuo Nakamura, and Sho-ichi Yamagishi
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Glycation End Products, Advanced ,medicine.medical_specialty ,Receptor for Advanced Glycation End Products ,Diabetic angiopathy ,Bioinformatics ,medicine.disease_cause ,RAGE (receptor) ,chemistry.chemical_compound ,Diabetes mellitus ,Internal medicine ,Animals ,Humans ,Medicine ,Pharmacology (medical) ,Receptors, Immunologic ,Diabetic Vascular Complications ,Receptor ,Pharmacology ,business.industry ,General Medicine ,medicine.disease ,Blockade ,Oxidative Stress ,Endocrinology ,Pharmaceutical Preparations ,chemistry ,Advanced glycation end-product ,business ,Diabetic Angiopathies ,Oxidative stress ,Protein Binding - Abstract
Diabetic vascular complications are leading causes of acquired blindness, end-stage renal failure, a variety of neuropathies, and accelerated atherosclerosis, which together could account for disabilities and high mortality rates in patients with diabetes. Since there is accumulating evidence that the advanced glycation end product (AGE)-RAGE (receptor for AGEs)-oxidative stress axis is involved in diabetic vascular complications, inhibition of the AGE-RAGE system may be a promising target for therapeutic intervention in these devastating disorders.In this review, we discuss several types of agent that may be able to inhibit the AGE-RAGE-oxidative stress system, and their therapeutic implications in vascular complications in diabetes.We have analyzed currently available scientific literature in the field of AGE-RAGE to create a comprehensive review on novel therapeutic agents for vascular complications in diabetes.Inhibition of AGE formation, blockade of the AGE-RAGE interaction, and suppression of RAGE expression or its downstream pathways may be novel therapeutic strategies for the treatment of vascular complications in diabetes.
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- 2008
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25. Serum levels of soluble form of receptor for advanced glycation end products (sRAGE) are positively associated with circulating AGEs and soluble form of VCAM-1 in patients with type 2 diabetes
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Tsutomu Imaizumi, Hisashi Adachi, Takanori Matsui, Kazuo Nakamura, Masayoshi Takeuchi, Hiroyoshi Inoue, Sho-ichi Yamagishi, and Yayoi Kurita-Nakamura
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Glycation End Products, Advanced ,Male ,medicine.medical_specialty ,Receptor for Advanced Glycation End Products ,Cell ,Vascular Cell Adhesion Molecule-1 ,Coronary Artery Disease ,Type 2 diabetes ,Biochemistry ,Body Mass Index ,Diabetes Complications ,Coronary artery disease ,chemistry.chemical_compound ,Glycation ,Internal medicine ,Diabetes mellitus ,medicine ,Humans ,Diabetic Nephropathies ,Vascular Diseases ,Receptors, Immunologic ,VCAM-1 ,Receptor ,Aged ,Aged, 80 and over ,business.industry ,Cell Biology ,Middle Aged ,Intercellular Adhesion Molecule-1 ,medicine.disease ,Endocrinology ,medicine.anatomical_structure ,Diabetes Mellitus, Type 2 ,Solubility ,chemistry ,Multivariate Analysis ,Linear Models ,Female ,Cardiology and Cardiovascular Medicine ,business ,Body mass index ,Biomarkers - Abstract
We have recently found that soluble form of receptor for advanced glycation end products (sRAGE) levels are positively associated with inflammatory biomarkers and the presence of coronary artery disease (CAD) in type 2 diabetic patients. Since advanced glycation end products (AGEs) up-regulate RAGE expression and endogenous sRAGE could be generated from the cleavage of cell surface RAGE, it is conceivable that sRAGE is positively associated with circulating AGEs levels in diabetes. In this study, we examined whether sRAGE were correlated to circulating levels of AGEs and soluble forms of vascular cell adhesion molecule-1 (sVCAM-1) and intercellular adhesion molecule-1 (sICAM-1) in patients with type 2 diabetes. Eighty-two Japanese type 2 diabetic patients underwent a complete history and physical examination, determination of blood chemistries, sRAGE, AGEs, sVCAM-1 and sICAM-1. Multiple regression analysis revealed that serum levels of AGEs and sVCAM-1 were independently correlated with sRAGE. This study demonstrated that serum levels of sRAGE were positively associated with circulating AGEs and sVCAM-1 levels in type 2 diabetic patients. Our present observations suggest sRAGE level may be elevated in response to circulating AGEs, thus being a novel marker of vascular injury in patients with type 2 diabetes.
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- 2008
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26. A WEB-based integrated data processing system for the TRIAM-1M
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Shoji Kawasaki, Hideharu Nakashima, Kazuo Nakamura, A. Higashijima, Mizuki Sakamoto, Makoto Hasegawa, Kazuaki Hanada, Konosuke Sato, and Hiroshi Idei
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Web server ,Java ,business.industry ,Relational database ,Computer science ,Mechanical Engineering ,computer.software_genre ,Data processing system ,Nuclear Energy and Engineering ,Container (abstract data type) ,Operating system ,Web application ,General Materials Science ,Web service ,User interface ,business ,computer ,Civil and Structural Engineering ,computer.programming_language - Abstract
In TRIAM-1M, plasma discharge can be sustained for over five hours [H. Zushi, et al., Steady-state tokamak operation, ITB transition and sustainment and ECCD experiments in TRIAM-1M, Nucl. Fusion 45 (2005) S142–S156]. In order to avoid sitting in front of one console for the purpose of monitoring the plasma discharge, it is recommended that the experimental information be accessible from any location at any time. In addition, simple services to access experimental information are required in order to promote the participation of multiple researchers in the TRIAM-1M experiment. Thus, A WEB-based integrated data processing system that provides management for experiment planning, an experimental log, numerical data, and plasma supervision has been installed in the TRIAM-1M. These services are composed primarily of an Apache WEB server, a Tomcat JSP/Servlet container, and a MySQL relational database. This system is constructed using the object-oriented Java language, which is easy to maintain and develop because of the intrinsic characteristics of the Java language. When participating in experiments, researchers are required only to prepare a WEB browser on any platform and are no longer required to memorize complex operations because all services are provided with a uniform user interface through a WEB browser. Furthermore, with the integration of these services, the required information and numerical data can be provided promptly by tracing HTML links that are created dynamically by server applications.
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- 2008
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27. Role of Advanced Glycation End Products (AGEs) and Oxidative Stress in Diabetic Retinopathy
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Sho-ichi Yamagishi, Takanori Matsui, Kazuo Nakamura, Seiji Ueda, and Seiya Okuda
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Glycation End Products, Advanced ,medicine.medical_specialty ,Receptor for Advanced Glycation End Products ,Bioinformatics ,Benzoates ,Renin-Angiotensin System ,Glycation ,Internal medicine ,Diabetes mellitus ,Drug Discovery ,medicine ,Animals ,Humans ,Telmisartan ,Receptors, Immunologic ,Pharmacology ,Type 1 diabetes ,Diabetic Retinopathy ,business.industry ,Diabetic retinopathy ,medicine.disease ,Angiotensin II ,PPAR gamma ,Oxidative Stress ,Endocrinology ,Metabolic control analysis ,Benzimidazoles ,business ,Angiotensin II Type 1 Receptor Blockers ,Retinopathy ,medicine.drug - Abstract
Diabetic retinopathy is a common and potentially devastating microvascular complication in diabetes and is a leading cause of acquired blindness among the people of occupational age. However, current therapeutic options for the treatment of sight-threatening proliferative diabetic retinopathy such as photocoagulation and vitrectomy are limited by considerable side effects and far from satisfactory. Therefore, to develop novel therapeutic strategies that specifically target diabetic retinopathy is actually desired for most of the patients with diabetes. Chronic hyperglycemia is a major initiator of diabetic retinopathy. However, recent clinical study has substantiated the concept of 'hyperglycemic memory' in the pathogenesis of diabetic retinopathy. Indeed, the Diabetes Control and Complications Trial-Epidemiology of Diabetes Interventions and Complications (DCCT-EDIC) Research, has revealed that the reduction in the risk of progressive retinopathy resulting from intensive therapy in patients with type 1 diabetes persisted for at least several years after the DCCT trial, despite increasing hyperglycemia. These findings suggest a long-term beneficial influence of early metabolic control on clinical outcomes in type 1 diabetic patients. Among various biochemical pathways implicated in the pathogenesis of diabetic retinopathy, the process of formation and accumulation of advanced glycation end products (AGEs) and their mode of action are most compatible with the theory 'hyperglycemic memory'. Further, there is a growing body of evidence that AGEs-RAGE (receptor for AGEs) interaction-mediated oxidative stress generation plays an important role in diabetic retinopathy. This article summarizes the role of AGEs and oxidative stress in the development and progression of diabetic retinopathy and the therapeutic interventions that could prevent this devastating disorder. We also discuss here the pathological crosstalk between the AGEs-RAGE and the renin-angiotensin system in diabetic retinopathy and a potential clinical utility of telmisartan, an angiotensin II type 1 receptor blocker with peroxisome proliferator-activated receptor-gamma-modulating activity.
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- 2008
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28. High accessible experimental information on CPD experiment
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Mizuki Sakamoto, Kazuo Nakamura, Konosuke Sato, A. Higashijima, Hiroshi Idei, Makoto Hasegawa, Shoji Kawasaki, Hideki Zushi, Hisatoshi Nakashima, and Kazuaki Hanada
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Multimedia ,Computer science ,Wireless network ,business.industry ,Mechanical Engineering ,Mobile Web ,computer.software_genre ,Software portability ,Nuclear Energy and Engineering ,Mobile phone ,Personal computer ,Mobile search ,General Materials Science ,The Internet ,Web service ,business ,computer ,Civil and Structural Engineering - Abstract
On CPD [1] (Compact PWI experimental Device) experiment, information of electronic logbook and sequence status are distributed by Web services to prepare future experimental environment such as steady state operation and remote participation. Hence, all the researchers can acquire information with a Web browser installed on a personal computer if they are connected to the Internet. However, to carry a notebook computer all the time is a burden to researchers. Furthermore, the researchers may not be always connected to the Internet. Mobile phones are superior in portability compared to notebook computers, and are easy to connect with Internet through the wireless network of the telecom carriers. Moreover, since recent mobile phones have full browsing function, their affinities to the Web services are becoming high. On this account, Web services for mobile phones are developed to access experimental information. For sequence monitoring, a mobile application MIDlet that utilizes special functions of mobile phone such as sound and vibration is also developed to draw attentions of researchers to sequence status.
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- 2008
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29. Pigment epithelium-derived factor (PEDF) administration inhibits occlusive thrombus formation in rats: A possible participation of reduced intraplatelet PEDF in thrombosis of acute coronary syndromes
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Shin-ichiro Ueda, Sho-ichi Yamagishi, Yoshio Katsuki, Yousuke Katsuda, Yuko Jinnouchi, Takanori Matsui, Tsutomu Imaizumi, Yumiko Yoshida, Kazuo Nakamura, and Katsuhiko Takenaka
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Blood Platelets ,Pathology ,medicine.medical_specialty ,Platelet Aggregation ,P-selectin ,Arterial Occlusive Diseases ,Pharmacology ,Rats, Sprague-Dawley ,Coronary circulation ,PEDF ,Superoxides ,medicine ,Animals ,Humans ,Platelet ,Carotid Artery Thrombosis ,Nerve Growth Factors ,Platelet activation ,Acute Coronary Syndrome ,Thrombus ,Eye Proteins ,Serpins ,Dose-Response Relationship, Drug ,business.industry ,NADPH Oxidases ,medicine.disease ,Thrombosis ,Rats ,Disease Models, Animal ,P-Selectin ,medicine.anatomical_structure ,Reactive Oxygen Species ,Cardiology and Cardiovascular Medicine ,business - Abstract
Objectives Although remarkable therapeutic advances in the treatment of acute coronary syndromes (ACS) have been made with anti-platelet therapy, the therapeutic options may be limited by considerable side effects. Pigment epithelium-derived factor (PEDF) has anti-oxidative properties and may play a protective role against atherosclerosis. In this study, we investigated whether PEDF prevented occlusive thrombus formation in rats. Methods and results Occlusive thrombus formation was induced by treating rats with ligation and cuff placement at the left common carotid artery. Intravenous injection of PEDF dose-dependently inhibited thrombus formation and blocked the increase in immunoreactivity of P-selectin, a marker of platelet activation, NADPH oxidase activity and superoxide generation in thrombi. In vitro , PEDF significantly decreased collagen-induced reactive oxygen species generation in platelets and subsequently suppressed the platelet activation and aggregation. Plasma and intraplatelet levels of PEDF in the coronary circulation in patients with ACS were significantly lower than those in age- and gender-matched controls without coronary artery disease. Conclusions These results demonstrated that PEDF administration could inhibit occlusive thrombus formation by blocking the platelet activation and aggregation through its anti-oxidative properties. Our present study suggests that pharmacological up-regulation or substitution of PEDF may offer a promising strategy for the treatment of arterial thrombosis.
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- 2008
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30. Urinary Human L-FABP Is a Potential Biomarker to Predict COX-Inhibitor-Induced Renal Injury
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Eisei Noiri, Rui Maeda, Kazuo Nakamura, Toshiro Fujita, Momokazu Goto, Takeshi Sugaya, Didier Portilla, Tamami Tanaka, Kousuke Negishi, and Tokunori Yamamoto
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Male ,Nephrology ,medicine.medical_specialty ,Physiology ,Urinary system ,Mice, Transgenic ,Urine ,Fatty Acid-Binding Proteins ,Kidney ,Mice ,Predictive Value of Tests ,Internal medicine ,Genetics ,medicine ,Animals ,Humans ,Cyclooxygenase Inhibitors ,Blood urea nitrogen ,Mice, Inbred ICR ,biology ,business.industry ,General Medicine ,medicine.disease ,Mice, Inbred C57BL ,Meloxicam ,Endocrinology ,Mice, Inbred CBA ,biology.protein ,Biomarker (medicine) ,Kidney Diseases ,lipids (amino acids, peptides, and proteins) ,Cyclooxygenase ,business ,Biomarkers ,medicine.drug ,Kidney disease - Abstract
Background/Aim: A strong demand exists for the development of sensitive biomarkers in the nephrology field. We propose urinary human L-type fatty acid binding protein (L-FABP) as an earlier biomarker to detect the outcome of chronic renal injury induced by cyclooxygenase (COX) inhibitors using human L-FABP transgenic mice. Methods: After consuming a low-sodium diet for 2 weeks, transgenic mice were administered meloxicam or celecoxib with the low-sodium diet. Mice were sacrificed 2 days and 4 weeks after starting COX inhibitors, and urine was collected 24 and 48 h and 1, 2, 3, and 4 weeks after starting COX inhibitors. Celecoxib-treated mice were divided into responders or nonresponders according to urinary L-FABP levels, and histology, urinary L-FABP and peritubular capillary blood flow were evaluated. Results: Meloxicam-treated mice showed a higher blood pressure than control mice. Urinary L-FABP was significantly increased in COX inhibitor-treated mice. Peritubular capillary blood flow in all meloxicam-treated mice and in some celecoxib-treated mice was significantly decreased. Although blood urea nitrogen was not increased, interstitial fibrosis and macrophage infiltration were revealed, especially in meloxicam-treated mice. Responders showed an increase of fibrotic areas and correlations between urinary L-FABP and peritubular capillary blood flow. Conclusion: Urinary L-FABP is capable of revealing chronic renal injury induced by COX inhibitors.
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- 2008
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31. Development of Axle Bearing Lip-type Seal for High-speed Shinkansen Vehicles
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Shogo Mamada, Sumiko Hibino, Masanori Hansaka, Tetsuya Hosoya, Kazuo Nakamura, and Hirofumi Yoshida
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Engineering ,Axle ,Bearing (mechanical) ,business.industry ,law ,Mechanical Engineering ,Mechanical engineering ,business ,Seal (mechanical) ,Automotive engineering ,law.invention - Published
- 2008
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32. An Improved Grease Pocket for Extended Grease Service Life
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Tetsuya Hosoya, Kazuo Nakamura, and Sumiko Hibino
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Engineering ,business.industry ,Mechanical Engineering ,Grease ,Service life ,Tribology ,business ,Automotive engineering ,Traction motor - Published
- 2008
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33. Olmesartan blocks advanced glycation end products (AGEs)-induced angiogenesis in vitro by suppressing receptor for AGEs (RAGE) expression
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Seiji Ueda, Hiroyoshi Inoue, Tsutomu Imaizumi, Kei Fukami, Masayoshi Takeuchi, Kazuo Nakamura, Takanori Matsui, Seiya Okuda, and Sho-ichi Yamagishi
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DNA Replication ,Glycation End Products, Advanced ,Vascular Endothelial Growth Factor A ,medicine.medical_specialty ,endocrine system diseases ,Angiogenesis ,Receptor for Advanced Glycation End Products ,Down-Regulation ,Tetrazoles ,Angiogenesis Inhibitors ,Transfection ,Biochemistry ,Pathogenesis ,chemistry.chemical_compound ,Glycation ,Internal medicine ,medicine ,Humans ,RNA, Messenger ,cardiovascular diseases ,Receptors, Immunologic ,Promoter Regions, Genetic ,Receptor ,Autocrine signalling ,Cells, Cultured ,Diabetic Retinopathy ,Neovascularization, Pathologic ,business.industry ,Imidazoles ,NF-kappa B ,Endothelial Cells ,Cell Biology ,Angiotensin II ,Vascular endothelial growth factor ,Endocrinology ,chemistry ,Research Design ,Cancer research ,Cardiology and Cardiovascular Medicine ,Olmesartan ,business ,Angiotensin II Type 1 Receptor Blockers ,medicine.drug - Abstract
We have previously shown that advanced glycation end products (AGEs)–their receptor (RAGE) interaction elicits angiogenesis through autocrine production of vascular endothelial growth factor (VEGF), thus suggesting the active involvement of the AGEs–RAGE system in proliferative diabetic retinopathy (PDR). Since the crosstalk between the AGEs–RAGE and the renin–angiotensin system has also been proposed in the pathogenesis of PDR, we investigated here whether olmesartan, an angiotensin II type 1 receptor blocker, inhibited the AGEs-elicited angiogenesis in vitro by suppressing the NF-κB-mediated RAGE expression. Olmesartan significantly inhibited the AGEs-induced NF-κB promoter activity and RAGE gene expression in cultured microvascular endothelial cells (ECs). Further, olmesartan was found to block the AGEs-induced up-regulation of VEGF mRNA levels and consequent increase in DNA synthesis in ECs. These results demonstrated for the first time that olmesartan inhibited the AGEs signaling to angiogenesis by suppressing RAGE expression in ECs. Our present study suggests that blockade of the renin–angiotensin system by olmesartan may play a protective role against PDR by attenuating the deleterious effects of AGEs via down-regulation of RAGE.
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- 2008
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34. Circulating advanced glycation end products (AGEs) and soluble form of receptor for AGEs (sRAGE) are independent determinants of serum monocyte chemoattractant protein-1 (MCP-1) levels in patients with type 2 diabetes
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Hiroyoshi Inoue, Masayoshi Takeuchi, Yayoi Kurita-Nakamura, Sho-ichi Yamagishi, Takanori Matsui, Hisashi Adachi, Kazuo Nakamura, and Tsutomu Imaizumi
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Glycation End Products, Advanced ,Male ,medicine.medical_specialty ,Chemokine ,Endocrinology, Diabetes and Metabolism ,Receptor for Advanced Glycation End Products ,Type 2 diabetes ,Endocrinology ,Glycation ,Internal medicine ,Diabetes mellitus ,Internal Medicine ,medicine ,Humans ,Receptors, Immunologic ,Receptor ,Chemokine CCL2 ,Aged ,biology ,Adiponectin ,business.industry ,Vascular disease ,Monocyte ,Middle Aged ,medicine.disease ,medicine.anatomical_structure ,Diabetes Mellitus, Type 2 ,Solubility ,biology.protein ,Regression Analysis ,Female ,business - Abstract
Background Atherosclerosis is an inflammatory disease. Monocyte chemoattractant protein-1 (MCP-1) is an essential chemokine responsible for the recruitment of monocytes to inflammatory lesions in the vasculature, an initial step of atherosclerosis. Since serum levels of MCP-1 are higher in patients with type 2 diabetes, inhibition of MCP-1 may be a novel therapeutic target for prevention of accelerated atherosclerosis in diabetes. However, little is known about the regulation and determinants of serum MCP-1 levels in patients with diabetes. In this study, we examined the determinants of serum MCP-1 levels in type 2 diabetic patients. Methods Eighty-six consecutive outpatients with type 2 diabetes (36 male and 50 female; mean age 68.4 ± 9.6) underwent a complete history and physical examination, determination of blood chemistries, MCP-1, tumour necrosis factor-α, adiponectin, advanced glycation end products (AGEs), and soluble form of receptor for AGEs (sRAGE). We examined the association between MCP-1 levels and those in anthropometric, metabolic and inflammatory variables in these subjects. Results Univariate regression analysis showed that serum levels of MCP-1 were positively associated with AGEs (r = 0.386, p < 0.001) and sRAGE (r = 0.315, p < 0.001). After adjusting for age and sex, AGEs (p < 0.001) and sRAGE (p < 0.05) still remained significant. Conclusion The results demonstrate for the first time that circulating levels of AGEs and sRAGE are independent determinants of serum MCP-1 levels in patients with type 2 diabetes. Our present observations suggest the AGEs-RAGE system may be mainly involved in the elevation of MCP-1 in type 2 diabetic patients. Copyright © 2007 John Wiley & Sons, Ltd.
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- 2008
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35. Potential Utility of Telmisartan, an Angiotensin II Type 1 Receptor Blocker with Peroxisome Proliferator-Activated Receptor-γ (PPAR-γ)-Modulating Activity for the Treatment of Cardiometabolic Disorders
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Sho-ichi Yamagishi, Takanori Matsui, and Kazuo Nakamura
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Glycation End Products, Advanced ,medicine.medical_specialty ,Peroxisome proliferator-activated receptor ,Angiotensin-Converting Enzyme Inhibitors ,Pharmacology ,Benzoates ,Biochemistry ,Partial agonist ,Renin-Angiotensin System ,Insulin resistance ,Internal medicine ,Diabetes mellitus ,medicine ,Animals ,Humans ,Telmisartan ,Receptor ,Molecular Biology ,Metabolic Syndrome ,chemistry.chemical_classification ,business.industry ,General Medicine ,medicine.disease ,Angiotensin II ,PPAR gamma ,Endocrinology ,chemistry ,Molecular Medicine ,Benzimidazoles ,Metabolic syndrome ,business ,medicine.drug - Abstract
The metabolic syndrome is strongly associated with insulin resistance and consists of a constellation of factors such as hypertension and hyperlipidemia that raise the risk for cardiovascular diseases and diabetes mellitus. There is widespread agreement that the renin-angiotensin system (RAS) plays a pivotal role in the pathogenesis of insulin resistance and cardiovascular disease in diabetes. Indeed, large clinical trials have demonstrated substantial benefit of the blockade of this system for cardiovascular end-organ protection. Thus the blockade of the RAS may be a promising strategy for the treatment of the patients with the metabolic syndrome. Although several types of angiotensin II type 1 (AT(1)) receptor blockers (ARBs) are commercially available for the treatment of patients with hypertension, we have recently found that telmisartan (Micardis) could have the strongest binding affinity to AT(1) receptor. Further, telmisartan is reported to act as a partial agonist of peroxisome proliferator-activated receptor-gamma (PPAR-gamma). These observations suggest that, due to its unique PPAR-gamma-modulating activity, telmisartan may be one of the most promising sartans for the treatment of cardiometabolic disorders. In this paper, we reviewed the potential utility of telmisartan in insulin resistance and vascular complications in diabetes.
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- 2007
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36. Discrimination of Sidewalk Surface Condition Based on Image Textures and Meteorological Information
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Kazuo Nakamura and Handri Santoso
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Human-Computer Interaction ,Surface (mathematics) ,Image texture ,Artificial Intelligence ,business.industry ,Computer science ,Computer vision ,Computer Vision and Pattern Recognition ,Artificial intelligence ,business ,Image (mathematics) ,Background image - Abstract
Slippery roads, especially during and after a heavy snow fall, may lead to accidents causing injuries and fatalities to vulnerable person such as the aged. In this context, it is important to keep pedestrian aware of sidewalk condition. This paper aims at proposing detection of several sidewalk conditions under different environment circumstance. At the front end, image and video processing is perrformed to separate background and foreground images. Background image features are extracted using several texture feature generators. In this study, factor analysis methods are employed to examine the pattern of correlations among variables, and to reduce data dimensionality. Finally, Artificial Neural Network is employed to discriminate sidewalk surface condition, i.e., dry, wet, or snow.
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- 2007
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37. Taurine at early reperfusion significantly reduces myocardial damage and preserves cardiac function in the isolated rat heart
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Goichi Yotsumoto, Yoshihiro Fukumoto, Takayuki Ueno, Iguro Y, Kazuo Nakamura, Tadaomi-Alfonso Miyamoto, and Ryuzo Sakata
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Cardiac function curve ,medicine.medical_specialty ,Taurine ,Time Factors ,Free Radicals ,Ischemia ,Infarction ,Myocardial Reperfusion Injury ,Emergency Nursing ,Cardiovascular Physiological Phenomena ,chemistry.chemical_compound ,Intensive care ,Internal medicine ,medicine ,Animals ,Lipid peroxide ,business.industry ,medicine.disease ,Rats ,chemistry ,Anesthesia ,Emergency Medicine ,Ventricular pressure ,Cardiology ,Cardiology and Cardiovascular Medicine ,business ,Perfusion - Abstract
Summary Objective The Myocardial protective effects of taurine (TA) are well known. We investigated the optimal phase of giving taurine to reduce myocardial ischaemia-reperfusion injury in isolated rat hearts. Methods Isolated rat hearts were subjected to 20min of global ischaemia followed by 60min of reperfusion under three different conditions: global ischaemia alone (control group; n =8); pre-ischaemic administration of taurine (pre-TA group; n =8), perfusion with 10mmol/L taurine for 10min just before ischaemia; post-ischaemic administration of taurine (post-TA group; n =8), perfusion with 10mmol/L taurine for the first 10min of reperfusion. Ventricular functional and biochemical variables, the area at risk (AAR), and infarct size (IS) after reperfusion were compared between groups. Results Recovery of ventricular function in the post-TA group was significantly greater than that in the control and pre-TA groups in terms of left ventricular pressure and rate-pressure product. Lipid peroxide product as a marker of oxidant stress in the post-TA group was significantly less than that in the control and pre-TA groups. AAR relative to left ventricular area in the post-TA group was significantly less than that in the control and pre-TA groups. IS relative to AAR in the post-TA group was significantly less than that in the control group. Conclusion Taurine administered before or after ischaemia prevents infarction; being a potent free radical scavenging antioxidant, it reduced myocardial injury and provided significantly better functional recovery when given immediately after reperfusion.
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- 2007
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38. Alterations in mRNA Expression of Myelin Proteins in the Sciatic Nerves and Brains of Streptozotocin-induced Diabetic Rats
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Atsushi Arahata, Toyokazu Saito, Tadashi Kurihara, Sen-ichi Furudate, Yoichi Tamai, Saburo Yagishita, Kunio Kitamura, Rei Kawashima, Kazuo Nakamura, Yoshikuni Fujita, Hisako Kojima, and Yoshiko Tokuyama
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Male ,medicine.medical_specialty ,DNA, Complementary ,Diabetic neuropathy ,Proteolipid protein 1 ,Neurology ,Blotting, Western ,Neural Conduction ,Biochemistry ,Diabetes Mellitus, Experimental ,Pathogenesis ,Cellular and Molecular Neuroscience ,Myelin ,Internal medicine ,Diabetes mellitus ,Animals ,Medicine ,Peripheral Nerves ,RNA, Messenger ,Rats, Wistar ,Brain Chemistry ,Motor Neurons ,chemistry.chemical_classification ,business.industry ,General Medicine ,Blotting, Northern ,medicine.disease ,Streptozotocin ,Sciatic Nerve ,Rats ,medicine.anatomical_structure ,Endocrinology ,nervous system ,chemistry ,DNA Probes ,business ,Glycoprotein ,Myelin P0 Protein ,Myelin Proteins ,medicine.drug - Abstract
Diabetic neuropathy is the most common complication of diabetes. We examined the levels and the mRNA expression of myelin proteins in the sciatic nerves and the brains of streptozotocin-induced diabetic rats. The diabetic rats exhibited a decrease in body weight, elevation of the blood glucose level and a decrease in motor nerve conduction velocity at 2 weeks after streptozotocin injection. In the sciatic nerves of diabetic rats, the level of P0 protein and its mRNA expression were markedly reduced at 20 weeks after the injection. In the brains, the levels of proteolipid protein and myelin-associated glycoprotein and their mRNA expression were selectively decreased at 20 weeks after the injection. This affected expression of myelin proteins was found even when no histological abnormalities were detectable. Considering the functional significance of myelin proteins, this impairment of protein expression is possibly involved in the pathogenesis of diabetic neuropathy, including that in brain disorders.
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- 2007
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39. Signal Transduction Therapy of Diabetic Vascular Complication
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Katsuhiko Takenaka, Tsutomu Imaizumi, Takanori Matsui, Yuko Jinnouchi, Yumiko Yoshida, Sho-ichi Yamagishi, and Kazuo Nakamura
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medicine.medical_specialty ,Endocrinology ,business.industry ,medicine ,Vascular complication ,Pharmacology (medical) ,Signal transduction ,Intensive care medicine ,business - Published
- 2007
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40. Discrimination of Pedestrian Images Using Shape Features and Neural Networks
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Kazuo Nakamura and Santoso Handri
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Artificial neural network ,Computer science ,business.industry ,ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION ,Centroid ,Pedestrian ,Video processing ,Image (mathematics) ,Front and back ends ,symbols.namesake ,Identification (information) ,Fourier transform ,symbols ,Computer vision ,Artificial intelligence ,business ,ComputingMethodologies_COMPUTERGRAPHICS - Abstract
Intelligent surveillance systems capable of discriminating pedestrians in the street are one of the main application areas of computer vision. This paper proposes a method to discriminate pedestrian images into several classes by using pedestrian shape features and artificial neural networks. To overcome the difficulty of pedestrian identification due to shape variation over time, several video-image processing and intelligent discrimination methods were adopted and developed. At the front end, image and video processing was performed to separate the background from the foreground images. The pedestrian shape features were extracted by Fourier transform, and then feed-forward neural networks with back-propagation learning algorithms were employed to discriminate among several classes of the moving pedestrian images, i.e., pedestrian, cyclist, or other non-pedestrian objects. The experimental results demonstrated the capability of the proposed system to discriminate pedestrians in a real life pedestrian environment. On average, discrimination accuracy was achieved in 82% and 87% using the complex number and the centroid distance function method, respectively.
- Published
- 2007
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41. Micromachining Characteristics of Sapphire with Fifth HG Nd:YAG Laser
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Kazuo Nakamura, Nobuo Yasunaga, Toshiyuki Noji, and Hideyuki Horisawa
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Materials science ,business.industry ,Mechanical Engineering ,Surface finish ,Laser ,Fluence ,law.invention ,X-ray laser ,Surface micromachining ,Optics ,Mechanics of Materials ,law ,Nd:YAG laser ,Sapphire ,High harmonic generation ,Optoelectronics ,General Materials Science ,business - Abstract
In order to reduce the thermal influences in laser machining of sapphire surface, effects of a short-pulse ultra-violet laser were investigated. For the UV laser, the Fifth harmonic generation (Fifth HG) wave of an Nd:YAG laser (wavelength:213nm) was utilized. Significant reduction of thermal damages on the surface was demonstrated with the Fifth HG pulses compared to longer wavelengths of the Nd:YAG laser. It was shown that the control of depth of bottom surface with reduced thermal influences was possible in lower fluence cases(less than 40 J/cm2) with a homogenized beam and smooth surface roughness Ra < 200nm was obtainable.
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- 2007
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42. The Use of Technical 'Standard All-on-Four' in the Maxilla
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Humberto Oswaldo Schwartz-Filho, William Cunha Brandt, Caio Vinicius Gonçalves Roman-Torres, Henri Kazuo Nakamura, Arthur Mauricio de Oliveira, and Guilherme Piragine Contador
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Nasal cavity ,Engineering ,Rehabilitation ,Maxillary sinus ,business.industry ,medicine.medical_treatment ,Dentistry ,Clinical Practice ,medicine.anatomical_structure ,Maxilla ,medicine ,Distraction osteogenesis ,All on four ,Implant ,business - Abstract
Among the factors that should be considered for the rehabilitation of atrophic jaws is mainly the anatomy of edentulous jaw, which offers trouble installing fixtures in view of the proximity to the maxillary sinus and nasal cavity. There are several possibilities to rehabilitate atrophic arcs, autogenous grafts, distraction osteogenesis, angled and short implants have been widely used in clinical practice. Thus, advanced surgical techniques are disclosed in the literature, such as the all-on-four standard technique. This technique consists of inserting four implants for a complete rehabilitation, and inclining a previously straight distal implant 45°, allowing anchorage in better bone (jaw previous zones), use of longer implants and decreasing the size of the prosthetic cantilever. The purpose of this literature review was to evaluate the scientific articles who observed the behavior of dental implants installed by the all-on- four technique in the maxilla. Initially, using the key words, 62 articles were obtained. After applying the inclusion criteria, 19 articles were selected. In each study the following were evaluated parameters: success rate of angled and axial implants, bone loss, and prosthetic complications. Finally, seven studies contemplated the requirements to be in this review. The literature of the art "all-on- four" standard in edentulous jaws showed that both angulated and axial implants have high success rate (92.8% to 99.3%) and similar bone loss. Therefore, the all-on-four standard technique is a viable option in the medium- and long-term for immediate fixed prosthetic rehabilitation in atrophic jaws.
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- 2015
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43. Current density calculation from particle orbit in RF-driven divertor plasma on QUEST
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Hisatoshi Nakashima, Kazuaki Hanada, Akihide Fujisawa, Fan Xia, Hideki Zushi, Shoji Kawasaki, Kazuo Nakamura, Makoto Hasegawa, Mahbub Alam, Yoshihiko Nagashima, K. Araki, Osamu Mitarai, Hiroshi Idei, Kazutoshi Tokunaga, and Aki Higashijima
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Physics ,Toroid ,Field (physics) ,business.industry ,Divertor ,Plasma ,Resonance (particle physics) ,Magnetic field ,Computational physics ,Optics ,Orbit (dynamics) ,Astrophysics::Earth and Planetary Astrophysics ,business ,Current density - Abstract
We investigate and calculate particle orbits and the effect of particle orbits on plasma current density for nonrelativistic resonance condition in the present RF-driven divertor plasma on QUEST. We surveyed particle orbits for different values of parallel refractive index, particle initial positions and pitch angles on fundamental and second harmonic resonance conditions. We observed that for fundamental harmonic resonance condition when particle orbits are plotted on the poloidal cross-section for positive values of parallel refractive index, these orbits are started from the resonance surface and produced their orbits around the LCFS (Large Closed Flux Surface). These orbits carry positive current. When particle orbits are plotted for negative values of parallel refractive index, these orbits are started from resonance surface, but remained at the inside of the LCFS. These orbits carry negative current that reduced the overall plasma current. For second harmonic resonance condition when particle orbits are plotted on the poloidal cross-section most of the orbits remained in inside the LCFS and carry positive current. When we consider the value of parallel refractive index −0.4 and +0.4 some particle orbits arrived at the limiter and become lost particles. On the other hand, when we consider particle initial positions 0.16 m or more vertically far from the mid plane some banana orbits are produced. These banana orbits make the current density profile maximum at low field side region. From this calculation we got a hollow current density profile with current density peak at the low field side region outside of the LCFS. From this calculation we can infer that parabolic current density profile is possible, if we set the resonance surface outside of the magnetic axis by increasing the toroidal magnetic field coil current and make the plasma position inward by increasing vertical field coil current.
- Published
- 2015
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44. Advantage of Ischemic Preconditioning for Hepatic Resection in Pigs
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Hiroki Yoshida, Jun Kadono, Mikio Fukueda, Naoki Ishizaki, Kentaro Gejima, Nobuo Hamada, Ryuzo Sakata, Mamoru Kaieda, Seigo Nishida, and Kazuo Nakamura
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Male ,medicine.medical_specialty ,Time Factors ,Swine ,medicine.medical_treatment ,Ischemia ,Necrosis ,chemistry.chemical_compound ,Postoperative Complications ,Lactate dehydrogenase ,medicine ,Animals ,Hepatectomy ,Aspartate Aminotransferases ,Ischemic Preconditioning ,Inflammation ,Endothelin-1 ,L-Lactate Dehydrogenase ,Tumor Necrosis Factor-alpha ,business.industry ,Microcirculation ,Blood flow ,medicine.disease ,Specific Pathogen-Free Organisms ,medicine.anatomical_structure ,Liver ,chemistry ,Reperfusion Injury ,Anesthesia ,Hepatocyte ,Ischemic preconditioning ,Surgery ,Histopathology ,Endothelin receptor ,business ,Blood Flow Velocity - Abstract
Background Ischemic preconditioning (IP) and intermittent inflow occlusion (IO) have provided beneficial outcomes in hepatic resection. However, comparison of these two procedures against warm hepatic ischemia-reperfusion injury has not been studied enough. Materials and methods Pigs that had undergone 65% hepatectomy were subjected to Control (120 min continuous ischemia, n = 6), IP (10 min ischemia and 10 min reperfusion, followed by 120 min continuous ischemia, n = 6), and IO (120 min ischemia in the form of eight successive periods of 15 min ischemia and 5 min reperfusion, n = 6). We evaluated hepatocyte injury by aspartate aminotransferase, lactate dehydrogenase and hepaplastin test, hepatic microcirculation by hepatic tissue blood flow (HTBF) and endothelin (ET)-1, inflammatory response by tumor necrosis factor-α (TNF-α), and histopathology after reperfusion. Results IP prevented hepatocyte injury, HTBF disturbance, and hepatocyte necrosis in histopathology as well as IO. These two groups showed significantly better outcomes than Control. IP produced significantly less ET-1 and TNF-α than IO. Conclusions IP ameliorated hepatic warm ischemia-reperfusion injury. Furthermore, IP gained more advantages in preventing chemokine production such as ET-1 and inflammatory response over IO. IP could take the place of IO for hepatectomy.
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- 2006
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45. Development of Scanning Near-Field Optical Microscope Working under Cryogenic Temperature and Strong Magnetic Field
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Akihisa Tomita, Shunsuke Kono, Kazuo Nakamura, and Akihiro Kirihara
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Physics ,Scanning Hall probe microscope ,Microscope ,business.industry ,Physics::Optics ,Conjugate focal plane ,Signal ,Atomic and Molecular Physics, and Optics ,Collimated light ,law.invention ,Magnetic field ,Optics ,Optical microscope ,law ,Near-field scanning optical microscope ,business - Abstract
We report on the development of a cantilever-based scanning near-field optical microscope (SNOM) working in an extreme environment, at cryogenic temperature around 10 K and under strong magnetic field up to 7 T. We designed a new optical system based on an infinite conjugate microscope, which extracts the near-field signal from a small aperture through a narrow chamber into free space as collimated light. Using this system, we successfully measured near-field and topographical images of a metal-hole sample simultaneously. Combining the local optical accessing technique with the external control of the electronic state, this SNOM system will be a powerful tool to study optical properties of semiconductor nanostructures.
- Published
- 2006
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46. Inhibitory effects of edaravone on the production of tumor necrosis factor-α in the isolated heart undergoing ischemia and reperfusion
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Katsushi Yamada, Takayuki Ueno, Hiroko Kariyazono, Yoshihiro Fukumoto, Shunji Onimaru, Ryuzo Sakata, Kazuo Nakamura, Akira Yabuki, and Ryuji Ikeda
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Male ,Cardiac function curve ,medicine.medical_specialty ,Blotting, Western ,Myocardial Infarction ,Ischemia ,Blood Pressure ,Myocardial Reperfusion Injury ,Pharmacology ,Immunoenzyme Techniques ,chemistry.chemical_compound ,Heart Rate ,Internal medicine ,Edaravone ,medicine ,Animals ,cardiovascular diseases ,Myocardial infarction ,Rats, Wistar ,Analysis of Variance ,Ventricular Remodeling ,Tumor Necrosis Factor-alpha ,business.industry ,Free Radical Scavengers ,medicine.disease ,Rats ,P-Selectin ,chemistry ,cardiovascular system ,Cardiology ,Ventricular pressure ,Tumor necrosis factor alpha ,Cardiology and Cardiovascular Medicine ,business ,Reperfusion injury ,Perfusion ,Antipyrine - Abstract
We evaluated the effects of edaravone, a hydroxyl radical scavenging agent, on the production of tumor necrosis factor-alpha (TNF-alpha) in myocardium, and the release of TNF-alpha and P-selectin from myocardium after ischemia-reperfusion injury in isolated Langendorff-perfused rat hearts. Cardiodynamic function at stable points during perfusion and 5, 15, 30, and 60 min after the initiation of reperfusion was evaluated by left ventricular developed pressure, rate of increase in left ventricular pressure and rate of decrease in ventricular pressure, coronary flow, and heart rate. At 60 min after the initiation of reperfusion, myocardial infarct size was estimated microscopically using triphenyltetrazolium chloride staining, and expression of TNF-alpha in myocardium was detected by Western blot and immunohistochemistry. At the same time points as the measurement of cardiodynamic function, TNF-alpha and the soluble form of P-selectin in coronary effluent were measured by enzyme immunoassay. At all time points during reperfusion, edaravone markedly improved cardiodynamic function and reduced myocardial infarct size in comparison to the control. In myocardium in the control, TNF-alpha was detected in the endothelial cells and other cells bearing some resemblance to interstitial cells and monocyte cells. Edaravone suppressed this cytokine expression in the corresponding sites. P-selectin as well as TNF-alpha was found in the coronary effluent of the control, and edaravone significantly decreased soluble P-selectin levels in comparison to the control (P0.01). Edaravone might have protective effects on cardiac function through reduction of infarct size via decrease of production of TNF-alpha in myocardium induced by ischemia-reperfusion injury and through reduction of the release of adhesion molecules such as P-selectin from vascular endothelial cells.
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- 2006
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47. Cardiovascular Disease in Diabetes
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Kazuo Nakamura, Katsuhiko Takenaka, Sho-ichi Yamagishi, Tsutomu Imaizumi, Takanori Matsui, and Yuko Jinnouchi
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Glycation End Products, Advanced ,medicine.medical_specialty ,Arterial disease ,Disease ,Diabetes Complications ,Renin-Angiotensin System ,Glycation ,Diabetes mellitus ,Internal medicine ,Drug Discovery ,Diabetes Mellitus ,Animals ,Humans ,Medicine ,In patient ,Mortality ,Therapeutic strategy ,Pharmacology ,Accelerated atherosclerosis ,business.industry ,General Medicine ,Atherosclerosis ,medicine.disease ,Oxidative Stress ,Postprandial ,Cardiovascular Diseases ,Hyperglycemia ,Cardiology ,business - Abstract
Diabetes is associated with a marked increase in the risk of atherosclerotic vascular disorders, including coronary, cerebrovascular, and peripheral artery disease. Cardiovascular disease (CVD) could account for disabilities and high mortality rates in patients with diabetes. In this paper, we review the molecular mechanisms for accelerated atherosclerosis in diabetes, especially focusing on postprandial hyperglycemia, advanced glycation end products (AGEs) and the renin-angiotensin system. We also discuss here the potential therapeutic strategy that specifically targets CVD in patients with diabetes.
- Published
- 2006
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48. Role of Advanced Glycation End Products (AGEs) in Thrombogenic Abnormalities in Diabetes
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Katsuhiko Takenaka, Sho-ichi Yamagishi, Kazuo Nakamura, Takanori Matsui, and Tsutomu Imaizumi
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Glycation End Products, Advanced ,medicine.medical_specialty ,Nephropathy ,Diabetes Complications ,Pathogenesis ,Cellular and Molecular Neuroscience ,Developmental Neuroscience ,Glycation ,Thromboembolism ,Internal medicine ,Diabetes mellitus ,Diabetes Mellitus ,medicine ,Animals ,Humans ,In patient ,Accelerated atherosclerosis ,Type 1 diabetes ,business.industry ,medicine.disease ,Endocrinology ,Neurology ,Disease Progression ,Cardiology ,business ,Retinopathy - Abstract
Accelerated atherosclerosis and microvascular complications are perhaps the leading cause of coronary heart disease, blindness and renal failure, which could account for disabilities and high mortality rates in patients with diabetes. Several thrombogenic abnormalities have been shown to play a central role in the pathogenesis of these devastating complications. However, the molecular mechanism for thrombogenic diathesis in diabetes is not fully elucidated. A recent clinical study, the Diabetes Control and Complications Trial-Epidemiology of Diabetes Interventions and Complications (DCCT-EDIC) Research, has revealed that the reduction in the risk of progressive retinopathy and nephropathy resulting from intensive therapy in patients with type 1 diabetes persist for at least several years, despite increasing hyperglycemia. Further, intensive therapy during the DCCT resulted in decreased progression of carotid intima-media thickness six years after the end of the trial as well. These clinical studies strongly suggest that so-called 'hyperglycemic memory' causes chronic abnormalities in diabetic vessels that are not easily reversed, even by subsequent, relatively good control of blood glucose. Among various biochemical pathways activated under diabetes, the process of formation and accumulation of advanced glycation end products (AGEs) and their mode of action are most compatible with the theory 'hyperglycemic memory'. In this review, we discuss the role of AGEs in thrombogenic abnormalities in diabetes.
- Published
- 2006
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49. Membership Categorization Device and Sequential Organization
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Kazuo Nakamura
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Sequential organization ,Categorization ,business.industry ,Order (business) ,Operations management ,Relevance (information retrieval) ,Artificial intelligence ,Sociology ,business ,computer.software_genre ,computer ,Natural language processing - Abstract
This paper aims to demonstrate the importance of using both the idea of membership categorization device (MCD) and findings of sequential organization at the same time in order to analyze interaction. First, it is shown that MCD is identified with findings of logico-grammatical analysis. Second, it is shown that MCD is in fact rejected by one of the methodological constraints laid by E. Schegloff, “The problem of procedural consequence”. Third, it is maintained that this rejection leads to the possibility that we cannot fully explicate members' description because it underestimates the relevance of MCD in each setting. Finally, an alternative is proposed: using both MCD and findings of sequential organization at the same time.
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- 2006
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50. Therapeutic Implications of Blockers of Advanced Glycation End Products (AGEs)-their Receptor (RAGE) System
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Tsutomu Imaizumi, Sho-ichi Yamagishi, Yuko Jinnouchi, Katsuhiko Takenaka, and Kazuo Nakamura
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Pharmacology ,Glycation ,business.industry ,Medicine ,Receptor ,business ,RAGE (receptor) - Published
- 2005
- Full Text
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