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Efficacy and safety of limited endoscopic sphincterotomy before self-expandable metal stent insertion for malignant biliary obstruction

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World Journal of Gastroenterology 2017年第9期23卷 1627-1636页

作者： Hyeong Seok Nam dae Hwan Kang Hyung Wook kim Cheol Woong Choi Su Bum Park Su Jin kim dae Gon Ryu Department of Internal Medicine Pusan National University School of Medicine and Research Institute for Convergence of Biomedical Science and TechnologyPusan National University Yangsan HospitalYangsan-siGyeongsangnam-do 50612South Korea

AIM To evaluate the safety and efficacy of limited endoscopic sphincterotomy (ES) before placement of selfexpandable metal stent(SEMS).METHODS This was a retrospective analysis of 244 consecutive patients with unresectable malignant biliary obstruction, who underwent placement of SEMSs following limited ES from December 2008 to February 2015. The diagnosis of malignant biliary obstruction and assessment of patient eligibility for the study was established by a combination of clinical findings, laboratory investigations, imaging and pathological results. All patients were monitored in the hospital for at least 24 h following endoscopic retrograde cholangio pancreatography(ERCP). The incidence of immediate or early post-ERCP complications such as post-ERCP pancreatitis(PEP) and bleeding related to limited ES were considered as primary outcomes. Also, characteristics and complications according to the cancer type were *** Among the 244 patients included, the underlying diagnosis was cholangiocarcinoma in 118 patients,pancreatic cancer in 79, and non-pancreatic or nonbiliary malignancies in the remaining 47 patients. Early post-ERCP complications occurred in 9 patients(3.7%), with PEP in 7 patients (2.9%; mild, 6; moderate, 1) and mild bleeding in 2 patients (0.8%). There was no significant association between the incidence of post-ERCP complications and the type of malignancy(cholangiocarcinoma vs pancreatic cancer vs others, P = 0.696) or the type of SEMS used (uncovered vs covered, P = 1.000). Patients who had more than one SEMS placed at the first instance were at a significantly higher risk of post-ERCP complications (one SEMS vs two SEMS, P = 0.031). No other factors were predictive of post-ERCP *** Limited ES is feasible and safe, and effectively facilitates the placement of SEMS, without any significant risk of PEP or severe bleeding.

关键词：内视镜的 sphincterotomy 内视镜后退 cholangio pancreatography 复杂并发症胰腺炎流血 Cholestasis 自我可扩充的金属 stent

Surface exsolution and local atomic structure of amorphous CeTiO_x

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Journal of Rare Earths 2019年第2期37卷 160-165页

作者： Seung-Hyeon Jo Soonok kim Jiseung Ryu dae-Seung Cho Bora Jeong Heesoo Lee Department of Materials Science and Engineering Pusan National University Department of Naval Architecture & Ocean Engineering Pusan National University Green Materials & Processes Group Ulsan Regional Division Korea Institute of Industrial Technology

We made precipitated nano-ceria(~5 nm) on the surface of the catalyst by heat treatment of Cesupersaturated amorphous CeTiOxto improve the oxygen storage properties of CeO_2. The catalysts were prepared by sol-gel methods and TiO_2 nanoparticles were preferentially generated as a core material to form selective Ce-supersaturated structure on the catalyst surface. Reaction temperature and amount of doping element are optimized to induce selective crystallization of CeO_2. Cee Ce(2 nd shell)bond around 0.38 nm of Ce L3-edge extended X-ray absorption fine structure is reduced and nanostructure of precipitated ceria on the surface is observed by HREM. The catalyst is present as amorphous with precipitated nano-CeO_2 on the surface. The de-NOxefficiency of the catalyst, which has precipitated CeO_2, improves by ~50% owing to the simultaneous reactions of the nano CeO_2 and the amorphous CeTiO_x.

关键词： Ce-Ti oxide Exsolution Amorphous catalyst Local atomic structure De-NO_x efficiency Rare earths

Effect of vehicle weight on natural frequencies of bridges measured from traffic-induced vibration

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Earthquake Engineering and Engineering Vibration 2003年第1期2卷 109-116页

作者： Chul-Young kim dae-Sung Jung Nam-Sik kim Soon-Duck Kwon Maria Q.Feng Dept.of Civil & Envir.Eng. Myongji UniversityKorea Professor Dept.of Civil & Envir.Eng. Myongji UniversityKorea Research Associate Hyundai Institute of Construction Technology Hyundai E&C Co.Ltd.Korea Chief Researcher Dept.of Civil Engineering Chonbuk National UniversityKorea Professor Dept.of Civil & Envir.Eng. University of CaliforniaIrvineCaliforniaUSA Professor

Recently,ambient vibration test(AVT)is widely used tu estimate dynamic characteristics of large civil struc- *** characteristics ean be affected by various envirnnmental factors such as humidity,intensity of wind,and *** these environmental conditions,tire mass of vehicles may change the measured valnes when traffic-in- duced vibration is used as a source of AVT tor *** effect of vehicle mass on dynamic characteristics is investigated through traffic-induced vibration tests on three bridges;(1)three-span suspension bridge(128m+404m+128m),(2) five-span continuous steel box girder bridge(59m+3@ 95m+59m),(3)simply supported plate girder bridge(46m). Acceleration histories of each measurement location under normal traffic are recorded for 30 minutes at *** recor- ded histories are divided into individual vibrations and are combined into two groups aceording to the level of vibration;one by heavy vehicles such as trucks and buses and the other by light vehicles such as passenger *** processing of the two groups of signals shows that,for the middle and long-span bridges,the difference can be hardly detected,but,for the short span bridges whose mass is relatively small,the measured natural frequencies can change up to 5.4%.

关键词： ambient vibration test traffic induced vibration vehicle mass suspension bridge short-span bridge dynamic characteristics natural frequency

Recommendation application for video head impulse test based on fuzzy logic control

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Journal of Central South University 2016年第5期23卷 1208-1214页

作者： NGUYEN Thi Anh Dao kim dae Young LEE Sang Min kim Kyu Sung Seong Ro Lee KWON Jang Woo Department of Computer and Information Engineering Inha University Department of Otorhinolaryngology Inha University Hospital Department of Electronic Engineering Inha University Department of Information and Electronics Engineering Mokpo National University

Vestibulo-ocular reflex(VOR) is an important biological reflex that controls eye movement to ensure clear vision while the head is in ***,VOR measurement is commonly done with a video head impulse test based on a velocity gain algorithm or a position gain algorithm,in which velocity gain is a VOR calculation on head and eye velocity,whereas position gain is calculated from head and eye *** aim of this work is first to compare the two algorithms' performance and to detect covert catch-up saccade,then to propose a stand-alone recommendation application for the patient's *** the first experiment,for ipsilesional and contralesional sides,the calculated position gain(0.94±0.17) is higher than velocity gain(0.84±0.19).Moreover,gain asymmetry of both lesion and intact sides using velocity gain is mostly higher than that from using position gain(four out of five subjects).Consequently,for subjects who have unilateral vestibular neuritis diagnosed from clinical symptoms and a vestibular function test,vestibular weakness is depicted by velocity gain much better than by position *** catch-up saccade and position gain then are used as inputs for recommendation applications.

关键词：模糊逻辑控制应用脉冲测试视频增益算法反射控制头部运动眼球运动

Effect of annealing on two different niobium-clad stainless steel PEMFC bipolar plate materials

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中国有色金属学会会刊：英文版 2009年第B9期19卷 56-60页

作者： Sung-Tae HONG dae-Wook kim Yong-Joo YOU K.Scott WEIL School of Mechanical and Automotive Engineering University of Ulsan Department of Material Science and Engineering University of Ulsan Pacific Northwest National Laboratory

Niobium (Nb)-clad stainless steels(SS) produced via roll bonding are being considered for use in the bipolar plates of polymer electrolyte membrane fuel cell(PEMFC) stacks. Because the roll bonding process induces substantial work hardening in the constituent materials, thermal annealing is used to restore ductility to the clad sheet so that it can be subsequently blanked, stamped and dimpled in forming the final plate component. Two roll bonded materials, niobium clad 340L stainless steel (Nb/340L SS) and niobium clad 434 stainless steel (Nb/434 SS) were annealed under optimized conditions prescribed by the cladding manufacturer. Comparative mechanical testing conducted on each material before and after annealing shows significant improvement in ductility in both cases. However, corresponding microstructural analyses indicate an obvious difference between the two heat treated materials. During annealing, an interlayer with thick less than 1 μm forms between the constituent layers in the Nb/340L SS, whereas no interlayer is found in the annealed Nb/434 SS material. Prior work suggests that internal defects potentially can be generated in such an interlayer during metal forming operations. Thus, Nb/434 SS may be the preferred candidate material for this application.

关键词：质子交换膜燃料不锈钢材料双极板材料退火条件复合板铌聚合物电解质微观结构分析

Calcium and Calmodulin-Mediated Regulation of Gene Expression in Plants

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Molecular Plant 2009年第1期2卷 13-21页

作者： Min Chul kim Woo Sik Chung dae-Jin Yun Moo Je Cho Division of Applied Life Science (BK21 Program) Plant Molecular Biology and Biotechnology Research Center and Environmental Biotechnology National Core Research Center Gyeongsang National University Jinju 660-701 Korea

Sessile plants have developed a very delicate system to sense diverse kinds of endogenous developmental cues and exogenous environmental stimuli by using a simple Ca^2＋ ion. Calmodulin （CAM） is the predominant Ca^2＋ sensor and plays a crucial role in decoding the Ca^2＋ signatures into proper cellular responses in various cellular compartments in eukaryotes. A growing body of evidence points to the importance of Ca^2＋ and CaM in the regulation of the transcriptional process during plant responses to endogenous and exogenous stimuli. Here, we review recent progress in the identification of transcriptional regulators modulated by Ca^2＋ and CaM and in the assessment of their functional significance during plant signal transduction in response to biotic and abiotic stresses and developmental cues.

关键词： Abiotic/environmental stress calcium signaling/transport gene expression.

Tribology of multilayer coatings for wear reduction: A review

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Friction 2017年第3期5卷 248-262页

作者： Mahdi KHADEM Oleksiy V.PENKOV Hee-Kyung YANG dae-Eun kim Department of Mechanical Engineering Yonsei University Seoul 03722 Republic of KoreaCenter for Nano-Wear Yonsei University Seoul 03722 Republic of Korea Center for Nano-Wear Yonsei University Seoul 03722 Republic of Korea Department of Mechanical Engineering Yonsei University Seoul 03722 Republic of Korea

Friction and wear phenomena encountered in mechanical systems with moving components are directly related to efficiency, reliability and life of the system. Hence, minimizing and controlling these phenomena to achieve the desired system performance is crucial. Among the numerous strategies developed for reducing friction and wear, coatings have been successfully utilized in various engineering applications to mitigate tribological problems. One of the benefits of coatings is that they may be fabricated using a variety of materials in several different forms and structures to satisfy the requirements of the operating conditions. Among many types, coatings that are comprised of a combination of materials in the form of a multilayer have been gaining much interest due to the added degree of freedom in tailoring the coating property. In this paper, the properties and development status of multilayer coating systems for tribological applications were reviewed with the aim to gain a better understanding regarding their advantages and limitations. Specifically, focus was given to Ti-based and Cr-based coatings since Ti and Cr were identified as important elements in multilayer coating applications. Emphasis was given to materials, design concepts, mechanical properties, deposition method, and friction and wear characteristics of these types of coatings.

关键词： multilayer coating friction wear tribology

Continuity control method of cutter posture vector for efficient five-axis machining

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Journal of Central South University 2011年第6期18卷 1969-1975页

作者： HWANG Jong-dae kim Sang-myung JUNG Hyun-chul JUNG Yoon-gyo School of Mechatronics Changwon National University

During five-axis machining of impeller, the excessive local interference avoidance leads to inconsistency of cutter posture, low quality of machined surface and increase of processing time. Therefore, in order to improve the efficiency of five-axis machining of impellers, it is necessary to minimize the cutter posture changes and create a continuous tool path while avoiding interference. By using an MC-space algorithm for interference avoidance, an MB-spline algorithm for continuous control was intended to create a five-axis machining tool path with excellent surface quality and economic feasibility. A five-axis cutting experiment was performed to verify the effectiveness of the continuity control. The result shows that the surface shape with continuous method is greatly improved, and the surface roughness is generally favorable. Consequently, the effectiveness of the suggested method is verified by identifying the improvement of efficiency of five-axis machining of an impeller in aspects of surface quality and machining time.

关键词：五轴加工矢量控制加工刀具连续性有效性验证姿势刀具姿态刀具路径

Brain-derived neurotrophic factor mediates macrophage migration inhibitory factor to protect neurons against oxygen-glucose deprivation

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Neural Regeneration Research 2020年第8期15卷 1483-1489页

作者： Su Hwan Bae Mi Ran Yoo Ye Yeong kim In Kyung Hong Mi Hee kim Seung Hak Lee dae Yul kim Department of Rehabilitation Medicine Asan Medical CenterUniversity of Ulsan College of MedicineSeoulRepublic of Korea Asan Institute for Life Sciences Asan Medical CenterUniversity of Ulsan College of MedicineSeoulRepublic of Korea

Macrophage migration inhibitory factor(MIF)is a chemokine that plays an essential role in immune system *** studies suggested that MIF protects neurons in ischemic ***,few studies are reported on the role of MIF in neurological recovery after ischemic *** purpose of this study is to identify the molecular mechanism of neuroprotection mediated by *** neuroblastoma cells were incubated in Dulbecco’s modified Eagle’s medium under oxygen-glucose deprivation(OGD)for 4 hours and then returned to normal aerobic environment for reperfusion(OGD/R).30 ng/mL MIF recombinant(30 ng/mL)or ISO-1(MIF antagonist;50μM)was administered to human neuroblastoma *** cell cultures were assigned to one of four groups:control,OGD/R,OGD/R with MIF,OGD/R with *** viability was analyzed using WST-1 *** levels of brain-derived neurotrophic factor(BDNF),microtubule-associated protein 2(MAP2),Caspase-3,Bcl2,and Bax were detected by western blot assay and immunocytochemistry in each group to measure apoptotic ***-1 assay results revealed that compared to the OGD/R group,cell survival rate was significantly higher in the OGD/R with MIF group and lower in the OGD/R with ISO-1 *** blot assay and immunocytochemistry results revealed that expression levels of BDNF,Bcl2,and MAP2 were significantly higher,and expression levels of Caspase-3 and Bax were significantly lower in the MIF group than in the OGD/R *** levels of BDNF,Bcl2,and MAP2 were significantly lower,and expression levels of Caspase-3 and Bax were significantly higher in the ISO-1 group than in the OGD/R *** administration promoted neuronal cell survival and induced high expression levels of BDNF,MAP2,and Bcl2(anti-apoptosis)and low expression levels of Caspase-3 and Bax(pro-apoptosis)in an OGD/R *** results suggest that MIF administration is effective for inducing expression of BDNF and leads to neuroprotection of neuronal cells

关键词： apoptosis brain-derived neurotrophic factor hypoxia in vitro ischemic stroke macrophage migration inhibitory factor nerve regeneration neuroprotective effect reperfusion