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Current status in remnant gastric cancer after distal gastrectomy

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World Journal of Gastroenterology 2016年第8期22卷 2424-2433页

作者： Masaichi Ohira Takahiro Toyokawa Katsunobu Sakurai Naoshi Kubo Hiroaki Tanaka Kazuya Muguruma masakazu yashiro Naoyoshi Onoda Kosei Hirakawa Department of Surgical Oncology Osaka City University Graduate School of Medicine

Remnant gastric cancer(RGC) and gastric stump cancer after distal gastrectomy(DG) are recognized as the same clinical entity. In this review, the current knowledges as well as the non-settled issues of RGC are presented. Duodenogastric reflux and denervation of the gastric mucosa are considered as the two main factors responsible for the development of RGC after benign disease. On the other hand, some precancerous circumstances which already have existed at the time of initial surgery, such as atrophic gastritis and intestinal metaplasia, are the main factors associated with RGC after gastric cancer. Although eradication of Helicobacter pylori(H. pylori) in remnant stomach is promising, it is still uncertain whether it can reduce the risk of carcinogenesis. Periodic endoscopic surveillance after DG was reported useful in detecting RGC at an early stage, which offers a chance to undergo minimally invasive endoscopic treatment or laparoscopic surgery and leads to an improved prognosis in RGC patients. Future challenges may be expected to elucidate the benefit of eradication of H. pylori in the remnant stomach if it could reduce the risk for RGC, to build an optimal endoscopic surveillance strategy after DG by stratifying the risk for development of RGC, and to develop a specific staging system for RGC for the standardization of the treatment by prospecting the prognosis.

关键词： Remnant gastric cancer Helicobacter pylori endoscopic treatment Surveillance laparoscopic surgery

Stability analysis of a noise control system in a duct by using delay differential equation

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Acta Mechanica Sinica 2009年第1期25卷 131-137页

作者： masakazu Haraguchi MOE Key Laboratory of Structure Mechanics and Control for Aircraft Nanjing University of Aeronautics and Astronautics

The paper deals with the criteria for the closed- loop stability of a noise control system in a duct. To study the stability of the system, the model of delay differential equation is derived from the propagation of acoustic wave governed by a partial differential equation of hyperbolic type. Then, a simple feedback controller is designed, and its closed- loop stability is analyzed on the basis of the derived model of delay differential equation. The obtained criteria reveal the influence of the controller gain and the positions of a sensor and an actuator on the closed-loop stability. Finally, numerical simulations are presented to support the theoretical results.

关键词： Stability analysis Delay differential equation Closed-loop stability Noise control Acoustic system

A new reduction-based LQ control for dynamic systems with a slowly time-varying delay

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Acta Mechanica Sinica 2009年第4期25卷 529-537页

作者： masakazu Haraguchi MOE Key Lab of Structure Mechanics and Control for Aircraft Nanjing University of Aeronautics and Astronautics

Time delays in the feedback control often dete- riorate the control performance or even cause the instability of a dynamic system. This paper presents a control strategy for the dynamic system with a constant or a slowly time-varying input delay based on a transformation, which sire-plifies the time-delay system the relation is discussed for into a delay-free one. Firstly, two existing reduction-based linear quadratic controls. One is continuous and the other is discrete. By extending the relation, a new reduction-based control is then developed with a numerical algorithm presented for practical control implementation. The controller suggested by the proposed method has such a promising property that it can be used for the cases of different values of an input time delay without redesign of controller. This property provides the potential for stabilizing the dynamic system with a time-varying input delay. Consequently, the application of the proposed method to the dynamic system with a slowly time-varying delay is discussed. Finally, numerical simulations are given to show the efficacy and the applicability of the method.

关键词： Time delay Time-varying delay State transformation System reduction Linear quadratic control

Estimating effects from trapped magnetic fluxes in superconducting magnetic levitation measurement

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仪器仪表学报 2008年第3期29卷 449-452页

作者： masakazu Nakanishi Metrology Institute of Japan National Institute of Advanced Industrial Science and Technology 1-1-1 Umezono Tsukuba-shi Ibaraki 305-8563 Japan

Superconducting magnetic levitation measurement is one of the most promising approaches to define mass standard based on the fundamental physical constants. However, the present system has unknown factors causing error larger than 50 ppm. We examined the effects of magnetic fluxes trapped in the superconducting coil and the superconducting floating body. When fluxes were trapped in either coil or floating body, their effects were able to be cancelled by reversing polarities of current and magnetic field, as had been believed. However, fluxes trapped in both coil and body induced an attractive force between them and caused error. In order to reduce the fluxes, the coil and the floating body should be cooled in low magnetic field in magnetic and electromagnetic shields.

关键词：截留磁通量超导电磁飘浮测量基本物理常量

Verification of Subseasonal-to-Seasonal Forecasts for Major Stratospheric Sudden Warmings in Northern Winter from 1998/99 to 2012/13

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Advances in Atmospheric Sciences 2020年第3期37卷 250-258页

作者： masakazu TAGUCHI Department of Earth Science Aichi University of Education

This study reports verification results of hindcast data of four systems in the subseasonal-to-seasonal(S2S)prediction project for major stratospheric sudden warmings(MSSWs)in northern winter from 1998/99 to 2012/*** report deals with average features across all MSSWs,and possible differences between two MSSW types(vortex displacement and split types).Results for the average features show that stratospheric forecast verifications,when further averaged among the four systems,are judged to be successful for lead times around 10 d or *** systems are skillful for lead times around 5 d,whereas the results vary among the systems for longer lead times.A comparison between the MSSW types overall suggests larger forecast errors or lower skill for MSSWs of the vortex split type,although the differences do not have strong statistical significance for almost all *** limitation is likely to at least partly reflect the small sample size of the MSSWs available.

关键词： major stratospheric sudden warmings forecast verification subseasonal-to-seasonal prediction project vortex displacement and split warmings

Epigenetic memory of drug exposure history controls neural stem cell quiescence in the adult brain

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Neural Regeneration Research 2024年第4期19卷 711-712页

作者： masakazu Iwamoto Taito Matsuda Department of Stem Cell Biology and Medicine Graduate School of Medical SciencesKyushu UniversityFukuokaJapan

Neural stem cells(NSCs)are the source of all neurons and glial cells(astrocytes and oligodendrocytes)in the central nervous *** adult mammalian brain retains NSCs in the subgranular zone of the dentate gyrus in the hippocampus and ventricular subventricular zone lining the lateral ventricle(Olpe and Jessberger,2022).Adult NSCs in rodents are preserved throughout life and continuously produce new neurons that integrate into the pre-existing neuronal network.

关键词： neural integrate continuously

Synthesis of Nitrogen-doped Titania by Solvothermal Reactions in Alcohols

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过程工程学报 2006年第3期6卷 472-476页

作者： Tsugio Sato Yohei Aida masakazu Komatsu 殷澍 Institute of Multidisciplinary Research for Advanced Materials Tohoku UniversitySendai 980-8577Japan

Nitrogen-doped titania nanoparticles were obtained by the homogeneous precipitation in hexamethylenetetraminetitanium trichloride-alcohol aqueous solutions at 90 ℃ followed by heating at 190 ℃. Anatase, rutile and brookite were obtained, where the crystallite size, specific surface area and color greatly changed as 5～50 nm, 20～200 m2/g and light gray to yellow, depending on the solvent and pH. The products after calcination were yellow, indicating doping with nitrogen ion. All colored titania showed photocatalytic activity under visible light irradiation for the oxidative decomposition of nitrogen monoxide in air. Especially, the nanoparticles of anatase type nitrogen-doped titania obtained using methanol aqueous solution showed excellent photocatalytic activity.

关键词： nitrogen-doped titania solvothermal synthesis alcohol photocatalysis nitrogen monoxide decomposition

A New Method of Portfolio Optimization Under Cumulative Prospect Theory

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Tsinghua Science and Technology 2018年第1期23卷 75-86页

作者： Chao Gong Chunhui Xu masakazu Ando Xiangming Xi Department of Risk Science in Finance and Management Chiba Institute of Technology Chiba 275-0016 Japan Department of Automation Tsinghua University Beijing 100084 China

In this paper, the portfolio selection problem under Cumulative Prospect Theory （CPT） is investigated and a model of portfolio optimization is presented. This model is solved by coupling scenario generation techniques with a genetic algorithm. Moreover, an Adaptive Real-Coded Genetic Algorithm （ARCGA） is developed to find the optimal solution for the proposed model. Computational results show that the proposed method solves the portfolio selection model and that ARCGA is an effective and stable algorithm. We compare the portfolio choices of CPT investors based on various bootstrap techniques for scenario generation and empirically examine the effect of reference points on investment behavior.

关键词： portfolio choice cumulative prospect theory bootstrap method adaptive real-coded genetic algorithm

HYERS-ULAM STABILITY OF SECOND-ORDER LINEAR DYNAMIC EQUATIONS ON TIME SCALES

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Acta Mathematica Scientia 2021年第5期41卷 1809-1826页

作者： Douglas R.ANDERSON masakazu ONITSUKA Department of Mathematics Concordia CollegeMoorheadMN 56562 USA Department of Applied Mathematics kayama University of ScienceOkayama700-0005Japan

We investigate the Hyers-Ulam stability(HUS)of certain second-order linear constant coefficient dynamic equations on time scales,building on recent results for first-order constant coefficient time-scale *** particular,for the case where the roots of the characteristic equation are non-zero real numbers that are positively regressive on the time scale,we establish that the best HUS constant in this case is the reciprocal of the absolute product of these two *** for instability are also given.

关键词： stability second order Hyers-Ulam time scales