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Redox regulation of fertilisation and the spermatogenic process

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Asian Journal of Andrology 2011年第3期13卷 420-423,511,512页

作者： Junichi Fujii satoshi Tsunoda Department of Biochemistry and Molecular Biology Graduate School of Medical Science Yamagata University Yamagata 990-9585 Japan Respiratory and Cardiovascular Diseases Research Center Research institute for Advanced Molecular Epidemiology Yamagata University Yamagata 990-9585 Japan Global COE Program for Medical Sciences Japan Society for the Promotion of Science Tokyo Japan

Oxidative stress is one of the major causes of male infertility; it damages spermatogenic cells, the spermatogenic process and sperm function. Recent advances in redox biology have revealed the signalling role of reactive oxygen species （ROS） that are generated by cells. While highly reactive oxidants, such as the hydroxyl radical, exert largely deleterious effects, hydrogen peroxide can feasibly serve as a signal mediator because it is moderately reactive and membrane permeable and because it can oxidize only limited numbers of functional groups of biological molecules. The amino acid side chain most sensitive to oxidation is cysteine sulphydryl, which is commonly involved in the catalysis of some enzymes. Although the reactivity of cysteine sulphhydryl is not very high in ordinary proteins, some phosphatases possess a highly reactive sulphydryl group at their catalytic centre and are thereby oxidatively inactivated by transiently elevated hydrogen peroxide levels after extracellular stimuli and under certain environmental conditions. Peroxiredoxins, in turn, show moderate hydrogen peroxide-reducing activity, and their role in the modulation of ROS-mediated signal transduction in ordinary cells, mediated by protecting phosphatases from oxidative inactivation, has attracted much attention. Although knowledge of the signalling role of ROS in the male reproductive system is limited at present, its significance is becoming a focal issue. Here, we present a review of the emerging signalling role of hydrogen peroxide in testes.

关键词： hydrogen peroxide oxidative stress peroxiredoxin signal transduction

DETERMINANT SOLUTIONS OF THE NONAUTONOMOUS DISCRETE TODA EQUATION ASSOCIATED WITH THE DEAUTONOMIZED DISCRETE KP HIERARCHY

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Journal of Systems Science & Complexity 2010年第1期23卷 153-176页

作者： satoshi TSUJIMOTO Department of Applied Mathematics and Physics Graduate School of InformaticsKyoto University

It is shown that the nonautonomous discrete Toda equation and its Backlund transformation can be derived from the reduction of the hierarchy of the discrete KP equation and the discrete two-dimensional Toda equation. Some explicit examples of the determinant solutions of the nonautonomous discrete Toda equation including the Askey-Wilson polynomial are presented. Finally we discuss the relationship between the nonautonomous discrete Toda system and the nonautonomous discrete Lotka- Volterra equation.

关键词： Askey-Wilson polynomial Darboux transformation discrete KP hierarchy nonautonomous discrete Lotka-Volterra equation nonautonomous discrete Toda equation.

Performance Test and Flow Measurement of Contra-Rotating Axial Flow Pump

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Journal of Thermal Science 2007年第1期16卷 7-13页

作者： Akinori Furukawa Toru Shigemitsu satoshi Watanabe Division of Mechanical Engineering Science Kyushu University744 MotookaNishi-kuFukuoka 819-0395JAPAN

An application of contra-rotating rotors has been proposed against a demand for developing higher specific speed axial flow pump. In the present paper, the advantage and disadvantage of using contra-rotating rotors are described in comparison with conventional type of rotor-stator, based on theoretical and experimental investigations. The advantages are as follows：（1） The pump is inherently designed as smaller sized and at lower rotational speed. （2） A stable head-characteristic curve for flow rate with negative slope appears. （3） As the rear rotor rotational speed is varied as independent control of front rotor, the wider range of high performance operation is obtained by rear rotor speed control in addition to front rotor speed control. The disadvantages are as follows：（1） The structure of double shaft system becomes complex. （2） The pump performance is inferior at over flow rate as the rear rotor loading is weakened. （3） The blade rows interaction from rear rotor to front rotor more strongly appears. Then the rear rotor design is a key to achieve higher pump performance. Some methods to overcome these disadvantages will be discussed in more details toward wider usage of contra-rotating axial flow pump in various industrial fields.

关键词： axial flow pump contra-rotating rotors multiphase flow rotational speed control blade rows interaction

Flow Electrification of Insulated Liquid in Metal Pipes

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Chinese Journal of Mechanical Engineering 2012年第6期25卷 1115-1120页

作者： ZHU Shouxin LIU Lin TAKAHASHI satoshi School of Information and Engineering Huzhou Teachers College Huzhou 313000 China Graduate School of Natural Science and Technology Okayama University Okayama Japan

When relative motion occurs between a liquid and a solid, the two phases carry electric charge with opposite signs. The created charge easily accumulates in the liquid, and the amount of the charge carried in an insulated liquid refers to many factors, such as contact area with the solid surface, the contact time, and so forth. However, current theories agree that the amount of charge created during flow electrification is proportional to the contact surface. In this paper, the classical wall current theory is applied to establish an interfacial electrical double-layer model of flow electrification phenomena when an insulated liquid passes over metal pipe surface. Meanwhile, in conjunction with charge relaxation function, the relation between the charge density and flow velocity, the contact time and the contact area is obtained during the liquid flowing process. The experimental result demonstrates that the flowing charge carried in the insulated liquid is not simply proportional to the contact area, but has a non-linear dependence on the contact area and the contact time. Moreover, down flow experimental equipment pipes of different length and diameter, and dielectric hydraulic oil VG46 are used in an experimental study of laminar flow, in order to understand electrification phenomena in dielectric liquid flowing over metal pipes of different length and aperture. If they both increase linearly, charge relaxation will increase exponentially. As a result, the test result verifies related theoretical analysis, and the method given provides a theoretical basis to analyze interracial electrical phenomena.

关键词： flow electrification metal pipes contact time relaxation

Study on the Effects of Flow in the Volute Casing on the Performance of a Sirocco Fan

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Journal of Thermal Science 2004年第3期13卷 199-206页

作者： Tsutomu ADACHI Naohiro SUGITA satoshi OHOMORI Faculty of Engineering Osaka Sangyo University 3-1-1 Nakagaito Daito Osaka JapanFaculty of Engineering Osaka Sangyo University 3-1-1 Nakagaito Daito Osaka JapanSanki Engineering Corporation Ltd.

The flow at the exit from the runner blade of a centrifugal fan with forward curved blades (a sirocco fan) sometimes separates and becomes unstable. We have conducted many researches on the impeller shape of a sirocco fan, proper inlet and exit blade angles were considered to obtain optimum performance. In this paper, the casing shape were decided by changing the circumferential angle, magnifying angle and the width, 21 sorts of casings were used. Performance tests, inner flow velocity and pressure distributions were measured as well. Computational fluid dynamic calculations were also made and compared with the experimental results. Finally, the most suitable casing shape for best performance is considered.

关键词： sirocco fan fan flow measurement flow in the casing CFD.

High Resolution Clinometers for Measurement of Roll Error Motion of a Precision Linear Slide

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Chinese Journal of Mechanical Engineering 2018年第5期31卷 8-16页

作者： Yuki Shimizu satoshi Kataoka Wei Gao Department of Finemechanics Tohoku University

This paper proposes a new method for measurement of the roll error motion of a slide table in a precision linear slide. The proposed method utilizes a pair of clinometers in the production process of a precision linear slide, where the roll error motion measurement will be carried out repeatedly to confirm whether the surface form errors of slide guideways in the linear slide are su ciently corrected by hand scraping process. In the proposed method, one of the clinometers is mounted on the slide table, while the other is placed on a vibration isolation table, on which the precision linear slide is mounted, so that influences of external disturbances can be cancelled. An experimental setup is built on a vibration isolation table, and some experiments are carried out to verify the feasibility of the proposed method.

关键词： Linear slide Clinometer Rotational error motion measurement

Simultaneous detection of the shuttling motion of liquid metal droplets in channels under alternating pressure and capacitive sensor signals

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Microsystems & Nanoengineering 2024年第2期10卷 83-90页

作者： Shinji Bono Ryotaro Nakai satoshi Konishi Research Organization of Science and Technology Ritsumeikan UniversityShigaJapan Ritsumeikan Advanced Research Academy KyotoJapan Ritsumeikan Global Innovation Research Organization Ritsumeikan UniversityShigaJapan Graduate School of Science and Engineering Ritsumeikan UniversityShigaJapan

Implementing a signal-switching mechanism for the selective use of integrated sensors and actuators plays a crucial role in streamlining the functionality of miniaturized ***,a liquid metal droplet(LMD)-based signal-switching mechanism is introduced to achieve such *** modulation with a 100-μm spatial resolution enabled precise control of the position of the LMDs within a *** integrating the channel with asymmetrically structured electrodes,the effect of the shuttle-like movement of LMD on the temporal changes in the overall capacitance was ***,analysis of the capacitive peaks revealed the directional movement of the LMDs,enabling estimation of the position of the LMDs without direct *** addition,we achieved successful signal extraction from the capacitive sensor that was linked to the activated electrodes,thereby enabling selective data *** proposed signal-switching mechanism method achieved a detection accuracy of~0.1 *** sensor’s ability to simultaneously detect the LMD position and generate a signal underscores its significant potential for multiplexing in multisensing systems,particularly in concealed environments,such as in vivo settings.

关键词： liquid thereby integrating

Molecular biomarkers for vascular cognitive impairment and dementia:the current status and directions for the future

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Neural Regeneration Research 2024年第12期19卷 2579-2580页

作者： satoshi Hosoki Perminder SSachdev Centre for Healthy Brain Ageing Discipline of Psychiatry and Mental HealthSchool of Clinical MedicineFaculty of Medicine and HealthUniversity of New South WalesSydneyAustralia Department of Neurology National Cerebral and Cardiovascular CenterOsakaJapan

Dementia is a syndrome with various underlying pathologies acting independently or in concert to cause cognitive *** development of disease-specific treatments and targeted prevention strategies requires precise clinical sub-typing via etiology and pathophysiological ***,recent research advances in biomarkers,especially for Alzheimer's disease(AD)diagnosis,have improved diagnostic precision for dementia.

关键词： prevention diagnosis impairment

Electron Temperature Measurement by Floating Probe Method Using AC Voltage

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Plasma Science and Technology 2016年第11期18卷 1089-1094页

作者： satoshi NODOMI Shuichi SATO Mikio OHUCHI Department of Electrical and Electronic Engineering Tokyo Denki University

This study presents a novel floating probe method to measure electron temperatures using a hollow cathode-type discharge tube. The proposed method detects a shift in the floating potential when an AC voltage is applied to a probe through an intermediary blocking capacitor. The shift in the floating potential is described as a function of the electron temperature and the applied AC voltage. The floating probe method is simpler than the Langmuir probe method because it does not require the measurement of volt-ampere characteristics. As the input AC voltage increases, the electron temperature converges. The electron temperature measured using the floating probe method with an applied sinusoidal voltage shows a value close to the first （tail） electron temperature in the range of the floating potential.

关键词： electrostatic probe Langmuir probe floating potential electron temperature sheath