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Advances in traction methods for endoscopic submucosal dissection:What is the best traction method and traction direction?

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World Journal of Gastroenterology 2022年第1期28卷 1-22页

作者： Mitsuru nagata Department of Endoscopy Shonan Fujisawa Tokushukai HospitalKanagawa 251-0041Japan

Endoscopic submucosal dissection(ESD)has been developed as a treatment for superficial gastrointestinal neoplasms,which can achieve en bloc resection regardless of the lesion ***,ESD is technically difficult because endoscopists cannot bring their hand into the gastrointestinal tract,unlike surgeons in regular *** is difficult to obtain sufficient tension in the dissection plane and a good field of ***,ESD is associated with a long procedure time and a high risk of adverse events in comparison with endoscopic mucosal *** methods have been developed to provide sufficient tension for the dissection plane and a good field of vision during the ESD ***,traction direction is limited in most traction methods,resulting in insufficient effect in some *** traction direction is considered important,there have been few investigations of its *** the first half of this review,important traction methods are discussed,including traction *** second half,appropriate traction methods for each organ are *** important considerations for traction method,such as ability to adjust traction strength,interference between traction device and endoscope,and the need for specialized devices are also discussed.

关键词： Endoscopic submucosal dissection Traction method Countertraction Traction direction Vertical traction

Experimental Study on Load Characteristics in a Floating Type Pendulum Wave Energy Converter

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Journal of Thermal Science 2014年第5期23卷 465-471页

作者： Tengen Murakami Yasutaka Imai Shuichi nagata Institute of Ocean Energy Saga University

A floating type pendulum wave energy converter(FPWEC) with a rotary vane pump as the power take-off system was proposed by Watabe et *** *** showed that this device had high energy conversion *** the previous research,the authors conducted 2D wave tank tests in regular waves to evaluate the generating efficiency of FPWEC with a power take-off system composed of pulleys,belts and a *** a result,the influence of the electrical load on the generating efficiency was ***,the load characteristics of FPWEC are pursued experimentally by using the servo motors to change the damping coefficient in this *** a later part of this paper,the motions of the model with the servo motors are compared with that of the case with the same power take-off system as the previous *** the above experiment,it may be concluded that the maximum primary conversion efficiency is achieved as high as 98%at the optimal load.

关键词： pendulum wave energy converter floating type load characteristics primary conversion efficiency

Adaptive Learning with Large Variability of Teaching Signals for Neural Networks and Its Application to Motion Control of an Industrial Robot

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International Journal of Automation and computing 2011年第1期8卷 54-61页

作者： Fusaomi nagata Keigo Watanabe Department of Mechanical Engineering Faculty of Engineering Tokyo University of Science Department of Intelligent Mechanical Systems Graduate School of Natural Science and Technology Okayama University

Recently, various control methods represented by proportional-integral-derivative （PID） control are used for robotic control. To cope with the requirements for high response and precision, advanced feedforward controllers such as gravity compensator, Coriolis/centrifugal force compensator and friction compensators have been built in the controller. Generally, it causes heavy computational load when calculating the compensating value within a short sampling period. In this paper, integrated recurrent neural networks are applied as a feedforward controller for PUMA560 manipulator. The feedforward controller works instead of gravity and Coriolis/centrifugal force compensators. In the learning process of the neural network by using back propagation algorithm, the learning coefficient and gain of sigmoid function are tuned intuitively and empirically according to teaching signals. The tuning is complicated because it is being conducted by trial and error. Especially, when the scale of teaching signal is large, the problem becomes crucial. To cope with the problem which concerns the learning performance, a simple and adaptive learning technique for large scale teaching signals is proposed. The learning techniques and control effectiveness are evaluated through simulations using the dynamic model of PUMA560 manipulator.

关键词： Neural networks large-scale teaching signal sigmoid function adaptive learning servo system PUMA560 manipulator trajectory following control nonlinear control.

Protein and non-protein sulfhydryls and disulfides in gastric mucosa and liver after gastrotoxic chemicals and sucralfate: Possible new targets of pharmacologic agents

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World Journal of Gastroenterology 2007年第14期13卷 2053-2060页

作者： Lajos Nagy Miki nagata Sandor Szabo Departments of Pathology Brigham & Women's Hospital Harvard Medical SchoolBostonMassachusetts 02115and Pathology and Laboratory Medicine ServiceDiagnostic & Molecular Medicine HCGVA Medical Center9901 East 7th St. Long BeachCA 90822United States Depts. of 3rd Internal Medicine and Family MedicineFaculty of MedicineUniversity of PecsH-7632 PecsHungary Departments of Pathology Brigham & Women's Hospital Harvard Medical SchoolBostonMassachusetts 02115and Pathology and Laboratory Medicine ServiceDiagnostic & Molecular Medicine HCGVA Medical Center9901 East 7th St. Long BeachCA 90822United States

AIM： To investigate the role of major non-protein and protein sulfhydryls and disulfides in chemically induced gastric hemorrhagic mucosal lesions （HML） and the mechanism of gastroprotective effect of sucralfate.METHODS： Rats were given 1 mL of 75% ethanol, 25%NaCl, 0.6 mol/L HCI, 0.2 mol/L NaOH or 1% ammonia solutions intragastrically （i.g.） and sacrificed 1, 3, 6 or 12 min later. Total （reduced and oxidized） glutathione （GSH ＋ GSSG）, glutathione disulfide （GSSG）, protein free sulfhydryls （PSH）, protein-glutathione mixed disulfides （PSSG） and protein cystine disulfides （PSSP） were measured in gastric mucosa and liver.RESULTS： Reduced glutathione （GSH） was depleted in the gastric mucosa after ethanol, HCI or NaCl exposure,while oxidized glutathione （GSSG） concentrations increased, except by HCI and NaOH exposure. Decreased levels of PSH after exposure to ethanol were observed,NaCl or NaOH while the total protein disulfides were increased. Ratios of reduced to oxidized glutathione or sulfhydrils to disulfides were decreased by all *** changes in thiol homeostasis were detected in the liver after i.g. abbreviation should be spelled out the first time here administration of ethanol. Sucralfate increased the concentrations of GSH and PSH and prevented the ethanol-induced changes in gastric mucosal thiol concentrations.CONCLUSION： Our modified methods are now suitable for direct measurements of major protein and nonprotein thiols/disulfides in the gastric mucosa or liver.A common element in the pathogenesis of chemically induced HML and in the mechanism of gastroprotective drugs seems to be the decreased ratios of reduced and oxidized glutathione as well as protein sulfhydryls and disulfides.

关键词： Non-protein and protein thiol Gastricmucosal injury Gastroprotection Sucralfate

Dynamics and geometry of developing planar jets based on the invariants of the velocity gradient tensor

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Journal of Hydrodynamics 2015年第6期27卷 894-906页

作者：吴楠楠 SAKAI Yasuhiko nagata Kouji ITO Yasumasa School of Electric Power Engineering China University of Mining and Technology Department of Mechanical Science and Engineering Nagoya University

Based on the direct numerical simulation （DNS）, the developing planar jets under different initial conditions, e.g., the con- ditions of the exit Reynolds number and the exit mean velocity profile, are investigated. We mainly focus on the characteristics of the invariants of the velocity gradient tensor, which provides insights into the evolution of the dynamics and the geometry of the planar jets along with the flow transition. The results show that the initial flow near the jet exit is strongly predominated by the dissipation over the enstrophy, the flow transition is accompanied by a severe rotation and straining of the flow elements, where the vortex structure evolves faster than the fluid element deformation, in the fully-developed state, the irrotational dissipation is dominant and the most probable geometry of the fluid elements should remain between the biaxial stretching and the axisymmetric stretching. In addition, with a small exit Re and a parabolic profile for the exit mean streamwise velocity, the decay of the mean flow field and the magnitude of the turbulent variables will be strengthened in the process of the flow transition, however, a large exit Re will promote the flow transition to the fully-developed state. The cross-impact between the exit Re and the exit mean velocity profile is also observed in the present study.

关键词： planar jet direct numerical simulation (DNS) velocity gradient tensor flow transition joint probability density function(joint pdf)

Impulse Turbine with 3D Guide Vanes for Wave Energy Conversion

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Journal of Thermal Science 2006年第1期15卷 27-30页

作者： Manabu TAKAO Toshiaki SETOGUCHI Kenji KANEKO Shuichi nagata Department of Mechanical Engineering Matsue National College of Technology 14-4 Nishiikuma-cho Matsue-shi Shimane 690-8518 Japan Department of Mechanical Engineering Saga University 1 Honjo-machi Saga-shi Saga 840-8502 Japan Institute of Ocean Energy Saga University 1 Honjo-machi Saga-shi Saga 840-8502 Japan

In this study, in order to achieve further improvement of the performance of an impulse turbine with fixed guide vanes for wave energy conversion, the effect of guide vane shape on the performance was investigated by experiment. The investigation was performed by model testing under steady flow condition. As a result, it was found that the efficiency of the turbine with 3D guide vanes are slightly superior to that of the turbine with 2D guide vanes because of the increase of torque by means of 3D guide vane, though pressure drop across the turbine for the 3D case is slightly higher than that for the 2D case.

关键词： fluid machinery impulse turbine guide vane wave energy conversion.

Fulminant gastrointestinal graft-versus-host disease concomitant with cytomegalovirus infection:Case report and literature review

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World Journal of Gastroenterology 2013年第4期19卷 597-603页

作者： Hidetaka Okubo Naoyoshi nagata Naomi Uemura Department of Gastroenterology and Hepatology National Center for Global Health and MedicineTokyo 162-8655Japan Department of Gastroenterology and Hepatology Kohnodai HospitalIchikawa 272-0827ChibaJapan

Here,we report a case of fulminant gastrointestinal graft-versus-host disease(GI-GVHD) with cytomegalovirus(CMV) infection in 44-year-old *** the difficulties associated with the treatment of GIGVHD and GI-CMV disease,the mucosal findings and the clinical course showed marked improvements during long-term clinical *** endoscopic findings were remarkable,with diffuse sloughing mucosa in the stomach and highly active inflammation and deep discrete ulcers throughout the *** in the CMV quantitative polymerase chain reaction results were correlated with the endoscopic mucosal findings and were useful for assessing the efficacy of the *** a definite diagnosis of GI-GVHD is generally made by endoscopy with biopsy,the gross appearance of this disease can vary depending on the *** this paper,we also conduct a literature review of patients with GI-GVHD.

关键词： Acute gastrointestinal graft-versus-host disease Allogenic stem-cell transplantation Cytomegalovirus gastrointestinal disease Cytomegaloviruspolymerase chain reaction Endoscopy

Machining Robot with Vibrational Motion and 3D Printer-like Data Interface

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International Journal of Automation and computing 2018年第1期15卷 1-12页

作者： Fusaomi nagata Keigo Watanabe Maki K. Habib Department of Mechanical Engineering Faculty of Engineering Tokyo University of Science Yamaguchi 1-1-1 Daigaku-Dori Sanyo-Onoda 756-0884 Japan Department of Intelligent Mechanical Systems Division of Industrial Innovation Sciences Graduate School of Natural Science and Technology Okayama University 3-1-1 Tsushima-naka Kita-ku Okayama 700-8530 Japan American University 113 Kasr E1 Eini Street Cairo 11511 Egypt

In this paper, a vibration motion control is proposed and implemented on a foamed polystyrene machining robot to suppress the generation of undesirable cusp marks, and the basic performance of the controller is verified through machining experiments of foamed polystyrene. Then, a 3 dimensional （3D） printer-like data interface is proposed for the machining robot. The 3D data inter- face enables to control the machining robot directly using stereolithography （STL） data without conducting any computer-aided man- ufacturing （CAM） process. This is done by developing a robotic preprocessor that helps to remove the need for the conventional CAM process by directly converting the STL data into cutter location source data called cutter location （CL） or cutter location source （CLS） data. The STL is a file format proposed by 3D systems, and recently is supported by many computer aided design （CAD）/CAM soft- waxes. The STL is widely used for rapid prototyping with a 3D printer which is a typical additive manufacturing system. The STL deals with a triangular representation of a curved surface geometry. The developed 3D printer-like data interface allows to directly control the machining robot through a zigzag path, rectangular spiral path and circular spiral path generated according to the information included in STL data. The effectiveness and usefulness of the developed system are demonstrated through actual machining experiments.

关键词： Computer integrated manufacturing machining robot computer aided design (CAD)/computer-aided manufacturing(CAM) cutter location (CL) data vibrational motion stereolithography (STL) data preprocessor 3 dimensional (3D) printer-likedata interface.

Rapid growth of nanostructure on tungsten thin film by exposure to helium plasma

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Plasma Science and Technology 2023年第4期25卷 1-4页

作者： Shuangyuan FENG Shin KAJITA Masayuki TOKITANI Daisuke nagata Noriyasu OHNO National Institute for Fusion Science National Institutes of Natural SciencesTokiGifu 509-5292Japan Graduate School of Frontier Sciences The University of TokyoKashiwaChiba 277-8561Japan Graduate School of Engineering Nagoya UniversityNagoya 464-8603Japan

A fiberform nanostructure was synthesized by exposing high-density helium plasma to a 100 nm thick tungsten thin film in the linear plasma device *** helium plasma exposure,the cross-section of samples was observed by a scanning electron microscope,transmission electron microscope,and focused ion beam scanning electron *** is shown that the thickness of the nanostructured layer increases significantly for only a short irradiation *** optical absorptivity remains high,even though it is exposed to helium plasma for a short *** usage of the thin film can shorten the processing time for nanostructure growth,which will be beneficial for commercial production.

关键词： helium plasma fiberform nanostructure rapid growth