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Thermal Conductivity and Tensile Properties of Carbon Nanofiber-Reinforced Aluminum-Matrix Composites Fabricated via Powder Metallurgy: Effects of Ball Milling and Extrusion Conditions on Microstructures and Resultant Composite Properties

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Acta Metallurgica Sinica(English Letters) 2019年第5期32卷 573-584页

作者： fumio Ogawa Shuji yamamoto Chitoshi Masuda Department of Mechanical Engineering College of Science and Engineering Ritsumeikan University Kanto Gakuin University Kagami Memorial Institute for Materials Science and Technology Waseda University

Carbon nanofiber(CNF)-reinforced aluminum-matrix composites were fabricated via ball milling and spark plasma sintering(SPS), SPS followed by hot extrusion and powder extrusion. Two mixing conditions of CNF and aluminum powder were adopted: milling at 90 rpm and milling at 200 rpm. After milling at 90 rpm, the mixed powder was sintered using SPS at 560 °C. The composite was then extruded at 500 °C at an extrusion ratio of 9. Composites were also fabricated via powder extrusion of powder milled at 200 rpm and 550 °C with an extrusion ratio of 9(R9) or 16(R16). The thermal conductivity and tensile properties of the resultant composites were evaluated. Anisotropic thermal conductivity was observed even in the sintered products. The anisotropy could be controlled via hot extrusion. The thermal conductivity of composites fabricated via powder extrusion was higher than those fabricated using other methods. However, in the case of specimens with a CNF volume fraction of 4.0%, the thermal conductivity of the composite fabricated via SPS and hot extrusion was the highest. The highest thermal conductivity of 4.0% CNF-reinforced composite is attributable to networking and percolation of CNFs. The effect of the fabrication route on the tensile strength and ductility was also investigated. Tensile strengths of the R9 composites were the highest. By contrast, the R16 composites prepared under long heating duration exhibited high ductility at CNF volume fractions of 2.0% and 5.0%. The microstructures of composites and fracture surfaces were observed in detail, and fracture process was elucidated. The results revealed that controlling the heating and plastic deformation during extrusion will yield strong and ductile composites.

关键词： Al composite Carbon nanofiber Ball milling Hot extrusion Microstructure and performance

Tubulopapillary adenoma of the gallbladder accompanied by bile duct tumor thrombus

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World Journal of Gastroenterology 2014年第26期20卷 8736-8739页

作者： Kentaroh yamamoto Fumio Yamamoto Atsuhiro Maeda Hirotsune Igimi Mami yamamoto Ryosuke Yamaguchi Yuichi Yamashita Department of Surgery Yamamoto Memorial Hospital Department of Internal Medicine Maeda Hospital Department of Gastroenterological Surgery Fukuoka University School of Medicine

Intraductal papillary mucinous neoplasm of the bile duct(IPNB)is recognized as a precancerous lesion;however,both its pathogenesis and progression remain unclear.We present here a case of IPNB arising from the gallbladder accompanied by bile duct tumor thrombus in a 79-year-old female.The resected specimen revealed a tubulopapillary adenoma with no malignant cells.This case suggests that even in the absence of malignant cells,these tumors can behave as malignant tumors requiring aggressive treatment.Even if no malignant cells are present,intraepithelial neoplasms occurring in the ampullopancreatobiliary tract can behave as malignant tumors.

关键词： Intraductal papillary mucinous neoplasm of the bil

Acute pancreatitis successfully diagnosed by diffusion-weighted imaging: A case report

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World Journal of Gastroenterology 2008年第35期14卷 5478-5480页

作者： Satoshi Shinya Takamitsu Sasaki Yoshifumi Nakagawa Zhang Guiquing Fumio Yamamoto Yuichi Yamashita Department of Gastroenterological Surgery Yamamoto Memorial Hospital88-4 HachiyagaramiNirimachiImariSaga 848-0031Japan Department of Gastroenterological Surgery Fukuoka University School of MedicineNanakuma 7-45-1Jonan-kuFukuoka 814-0180Japan

Diffusion-weighted imaging (DWI) is an established diagnostic method of acute stroke. The latest advances in magnetic resonance imaging (MRI) technology have greatly expanded the utility of DWI in the examination of various organs. Recent studies have revealed the usefulness of DWI for imaging of the liver, kidney, ovary, and breast. We report a patient with acute pancreatitis detected by DWI and discussed the efficacy of DWI in diagnosing acute pancreatitis. A 50-year old man presented with a primary complaint of abdominal pain. We performed both DWI and computed tomography (CT) for this patient. The signal intensity in a series of DWI was measured and the apparent diffusion coefficient (ADC) values were calculated to differentiate inflammation from normal tissue. Two experienced radiologists evaluated the grade of acute pancreatitis by comparing the CT findings. Initially, the pancreas and multiple ascites around the pancreas produced a bright signal and ADC values were reduced on DWI. As the inflammation decreased, the bright signal faded to an iso-signal and the ADC values returned to their normal level. There was no difference in the abilities of DWI and CT images to detect acute pancreatitis. However, our case indicates that DWI can evaluate the manifestations of acute pancreatitis using no enhancement material andhas the potential to replace CT as a primary diagnostic strategy for acute pancreatitis.

关键词：急性胰腺炎加权扩散成像表观扩散常数磁共振成像诊断

Transcriptional silencing of Dickkopf gene family by CpG island hypermethylation in human gastrointestinal cancer

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World Journal of Gastroenterology 2008年第17期14卷 2702-2714页

作者： Tadateru Maehata Hiroaki Taniguchi Hiroyuki yamamoto Katsuhiko Nosho Yasushi Adachi Nobuki Miyamoto Chie Miyamoto Noriyuki Akutsu Satoshi Yamaoka fumio Itoh Department of Gastroenterology and Hepatology St. Marianna University School of Medicine First Department of Internal Medicine Sapporo Medical University

AIM: To clarify alterations of Dickkopfs (Dkks) and Kremen2 (Krm2) in gastrointestinal cancer. METHODS: We investigated the expression profiles and epigenetic alterations of Dkks and Krm2 genes in gastrointestinal cancer using RT-PCR, tissue microarray analysis, and methylation specific PCR (MSP). Cancer cells were treated with the demethylating agent and/or histone deacetylase inhibitor. WST-8 assays and in vitro invasion assays after treatment with specific siRNA for those genes were performed. RESULTS: Dkks and Krm2 expression levels were reduced in a certain subset of the gastrointestinal cancer cell lines and cancer tissues. This was correlated with promoter hypermethylation. There were significant correlations between Dkks over-expression levels and beta-catenin over-expression in colorectal cancer. In colorectal cancers with beta-catenin over-expression, Dkk-1 expression levels were significantly lower in those with lymph node metastases than in those without. Down-regulation of Dkks expression by siRNA resulted in a significant increase in cancer cell growth and invasiveness in vitro.CONCLUSION: Down-regulation of the Dkks associated to promoter hypermethylation appears to be frequently involved in gastrointestinal tumorigenesis.

关键词：基因表达甲基化胃癌症状疗效

Successful endoscopic fragmentation of large hardened fecaloma using jumbo forceps

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World Journal of Gastrointestinal Endoscopy 2017年第2期9卷 91-94页

作者： Yasumasa Matsuo Hiroshi Yasuda Hiroyasu Nakano Miki Hattori Midori Ozawa Yoshinori Sato Yoshiko Ikeda Shun-Ichiro Ozawa Masaki Yamashita Hiroyuki yamamoto fumio Itoh Division of Gastroenterology and Hepatology Department of Internal MedicineSt.Marianna University School of MedicineKanagawa 216-8511Japan

We present a rare case of fecaloma, 7 cm in size, in the setting of systemic scleroderma. A colonoscopy revealed a giant brown fecaloma occupying the lumen of the colon and a colonic ulcer that was caused by the fecaloma. The surface of the fecaloma was hard, large and slippery, and fragmentation was not possible despite the use of various devices, including standard biopsy forceps, an injection needle, and a snare. However, jumbo forceps were able to shave the surface of the fecaloma and break it successfully by repeated biting for 6 h over 2 d. The ability of the jumbo forceps to collect large mucosal samples was also appropriate for achieving fragmentation of the giant fecaloma.

关键词： Fecaloma 巨大的活体检视钳全身的硬皮病混合结缔组织疾病

Treatment and prevention of gastrointestinal bleeding in patients receiving antiplatelet therapy

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World Journal of Critical Care Medicine 2015年第1期4卷 40-46页

作者： Hiroshi Yasuda Yasumasa Matsuo Yoshinori Sato Sun-ichiro Ozawa Shinya Ishigooka Masaki Yamashita Hiroyuki yamamoto fumio Itoh Division of Gastroenterology and Hepatology St. Marianna University School of Medicine

Antiplatelet therapy is the standard of care for the secondary prevention of acute coronary syndrome and ischemic stroke, especially after coronary intervention. However, this therapy is associated with bleeding complications such as gastrointestinal bleeding, which is one of the most common life-threatening complications. Early endoscopy is recommended for most patients with acute upper gastrointestinal bleeding. After successful endoscopic hemostasis, immediate resumption of antiplatelet therapy with proton-pump inhibitors(PPIs) is recommended to prevent further ischemic events. PPI prophylaxis during antiplatelet therapy reduces the risk of upper gastrointestinal bleeding. The potential negative metabolic interaction between PPIs and clopidogrel is still unclear.

关键词： Antiplatelet therapy Aspirin Clopidogrel Gastrointestinal bleeding Endoscopy Proton-pump inhibitor

An updated review of gastric cancer in the next-generation sequencing era:Insights from bench to bedside and vice versa

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World Journal of Gastroenterology 2014年第14期20卷 3927-3937页

作者： Hiroyuki yamamoto Yoshiyuki Watanabe Tadateru Maehata Ryo Morita Yoshihito Yoshida Ritsuko Oikawa Shinya Ishigooka Shun-ichiro Ozawa Yasumasa Matsuo Kosuke Hosoya Masaki Yamashita Hiroaki Taniguchi Katsuhiko Nosho Hiromu Suzuki Hiroshi Yasuda Yasuhisa Shinomura fumio Itoh Division of Gastroenterology and Hepatology Department of Internal MedicineSt. Marianna University School of Medicine Division of Cancer Cell Research Institute of Medical ScienceUniversity of Tokyo Department of Gastroenterology Rheumatology and Clinical ImmunologySapporo Medical University School of Medicine Department of Molecular Biology Sapporo Medical University School of Medicine

Gastric cancer(GC)is one of the most common malignancies and remains the second leading cause of cancer-related death worldwide.There is an increasing understanding of the roles that genetic and epigenetic alterations play in GCs.Recent studies using nextgeneration sequencing(NGS)have revealed a number of potential cancer-driving genes in GC.Whole-exome sequencing of GC has identified recurrent somatic mutations in the chromatin remodeling gene ARID1A and alterations in the cell adhesion gene FAT4,a member of the cadherin gene family.Mutations in chromatin remodeling genes(ARID1A,MLL3 and MLL)have been found in 47%of GCs.Whole-genome sequencing and whole-transcriptome sequencing analyses have also discovered novel alterations in GC.Recent studies of cancer epigenetics have revealed widespread alterations in genes involved in the epigenetic machinery,such as DNA methylation,histone modifications,nucleosome positioning,noncoding RNAs and microRNAs.Recent advances in molecular research on GC have resulted in the introduction of new diagnostic and therapeutic strategies into clinical settings.The antihuman epidermal growth receptor 2(HER2)antibody trastuzumab has led to an era of personalized therapy in GC.In addition,ramucirumab,a monoclonal antibody targeting vascular endothelial growth factor receptor(VEGFR)-2,is the first biological treatment that showed survival benefits as a single-agent therapy in patients with advanced GC who progressed after firstline chemotherapy.Using NGS to systematically identify gene alterations in GC is a promising approach with remarkable potential for investigating the pathogenesis of GC and identifying novel therapeutic targets,as well as useful biomarkers.In this review,we will summarize the recent advances in the understanding of the molecular pathogenesis of GC,focusing on the potential use of these genetic and epigenetic alterations as diagnostic biomarkers and novel therapeutic targets.

关键词： Next-generation sequencing Microsatellite instabil

通过测量电力输入预测磨料/工件界面的条件变化(英文)

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材料与冶金学报 2011年第1期10卷 70-75页

作者：山本和近藤康雄上原一刚小幡文雄日本鸟取大学 Tottori University Tottori 680-8552Japan

A monitoring system is proposed in order to detect the condition changes at abrasive/workpiece interface in abrasive cutoff operation.The system can detect the condition changes from the electric power change consumed by the driving motor of lapping tool.The electric power is strongly related with the abrasive effectiveness.When the abrasive effectiveness has been kept a normal state,the electric power also has been kept a constant value.The bodily removal of abrasive leads to reduce the electric power monotonously.The piling up of cutting chips leads to a peculiar electric power change;the electric power increased gradually at the beginning and then began to fluctuate periodically.The severe adhesion of cutting chips to the cutting edges leads to the loss of nominal function in the cutting edges and the electric power input was thus descended suddenly at an early stage of lapping.

关键词： flat lapping condition change abrasive/worlpiece interface electric power AISI304 A5052 Inconel713

缺血期补充硝酸甘油对离体大鼠心脏心肌缺血再灌注损伤的作用

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中国循环杂志 1999年第4期14卷 242-244页

作者：刘海波 Takayuki T su ji Fum io Y am amoto Tosh ia Fujisato Hidekazu H irai Fu jio Miyaw aki 中国医学科学院中国协和医科大学心血管病研究所阜外心血管病医院冠心病研究室北京市100037 日本国立循环器病中心

目的：观察离体大鼠心脏缺血期补充一氧化氮（ＮＯ）供体对缺血再灌注损伤的影响。　　方法：将２６只离体大鼠心脏缺血３０分，再灌注６０分。分为两组，用药组（１５只）及对照组（１１只）。用药组于缺血期给予４．４×１０－３ｍ... 详细信息

目的：观察离体大鼠心脏缺血期补充一氧化氮（ＮＯ）供体对缺血再灌注损伤的影响。　　方法：将２６只离体大鼠心脏缺血３０分，再灌注６０分。分为两组，用药组（１５只）及对照组（１１只）。用药组于缺血期给予４．４×１０－３ｍｍｏｌ／Ｌ硝酸甘油（ｎｉｔｒｏｇｌｙｃｅｒｉｎ，ＮＴＧ，一种ＮＯ供体），碳酸氢盐缓冲液灌注。对照组仅给予碳酸氢盐缓冲液灌注。全部心脏均测定ＮＯ释放量、肌酸激酶漏出量及（或）心脏功能。　　结果：用药组大鼠心脏，使用ＮＴＧ表现为两种效应。其中部分大鼠心脏（非心室颤动组，ｎ＝７），ＮＴＧ增加肌酸激酶漏出量，减弱再灌注期心脏功能的恢复，伴随缺血期ＮＯ释放量的增加。对另一部分大鼠心脏（心室颤动组，ｎ＝８），ＮＴＧ减少肌酸激酶的释放，但心脏于再灌注期持续心室颤动，缺血期ＮＯ释放量无明显增加。　　结论：缺血期给予同一剂量ＮＴＧ对心肌缺血再灌注损伤产生双重效应，既可增加心肌损伤，又可减轻心肌损伤。

关键词：一氧化氮硝酸甘油心肌缺血再灌注损伤