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Chinese Physics Letters 2012年第6期29卷 82-85页

作者： Chung-Seok kim Kyung-young JHANG Automotive Engineering Hanyang UniversityHangdang-dongSeongdong-guSeoul133-791South Korea Mechanical Engineering Hanyang UniversityHangdang-dongSeongdong-guSeoul133-791South Korea

We present innovative nonlinear acoustics for characterizing fatigue-induced micro-damage of austenitic stainless steel 316 subjected to high-cycle *** fatigue-driven deformations are accumulated at several positions near the middle of hourglass-shaped specimens.A bell-shaped curve of acoustic nonlinearity as a function of position is observed,and the variation in acoustic nonlinearity is attributed to the evolution of a lattice defect (dislocation) and stress-induced martensite based on transmission electron microscopy (TEM) *** oblique incidence technique using a longitudinal waveform is a potentially viable method for characterizing the high-cycle fatigue deformation of austenitic stainless steel 316 alloys.

关键词： fatigue steel martensite

Sandwich-type ordered mesoporous carbon/graphene nanocomposites derived from ionic liquid

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Nano Research 2016年第9期9卷 2696-2706页

作者： Ho Seok kim young Hwan kim Kwang Chul Roh Kwang-Bum kim Lab of Energy Storage Materials Department of Material Science & EngineeringYonsei UniversitySeou1120749Republic of Korea Energy & Environmental Division Korea Institute of Ceramic Engineering & TechnologyJinju 52851Republic of Korea

Sandwich-type ordered mesoporous carbon/graphene nanocomposites were successfully synthesized using 2D ordered mesoporous silica/graphene nanocomposites as the hard template and an ionic liquid as a N-rich carbon source. We used an ionic liquid of 1-(3-cyanopropyl)-3-methylimidazolium dicyanamide containing nitrile groups (–CN) in the cation and anion as a carbon precursor for the preparation of the nanocomposites. Nitriles do not decompose under thermal treatment in an inert gas atmosphere, but leave significant amounts of N-rich carbon materials. The nanocomposites had a large surface area (1,316 m2·g–1), an average pore diameter of 5.9 nm, and high electrical conductivity. The nanocomposite electrode showed a high specific capacitance of 190 F·g–1at 0.5 A·g–1in 1 M TEABF4/AN electrolyte and a good rate capability between 0 and 2.7 V for supercapacitor (or ultracapacitor) applications. [Figure not available: see fulltext.] © 2016, Tsinghua University Press and Springer-Verlag Berlin Heidelberg.

关键词： ionic liquid-derived carbon ordered mesoporous carbon/graphene nanocomposite 2D graphene nanocomposite supercapacitor

Grain size dependence of flow stress in ECAPed Ti with constant texture

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中国有色金属学会会刊：英文版 2012年第S3期22卷 673-677页

作者： Chang-young HYUN Ho-Kyung kim Department of Materials Science and Engineering Seoul National University of Science and Technology Department of Automotive Engineering Seoul National University of Science and Technology

The effect of grain size on the flow stress in an ECAPed Ti with a constant texture was investigated,assuming that 2,4,5 and 6 passes microstructures have a similar *** average size of recrystallized grains decreased to 0.5 μm,0.4 μm,and 0.3 μm with respect to the ECAP pass number of 2,4,and 6,*** ultimate tensile strength (UTS) and yield strength (YS) increase with an increase in the number of *** UTS and YS of the 6 passes ECAPed sample were found to be 740.2 MPa and 580.3 MPa,*** equation for the flow stress of an ECAPed Ti with a constant texture as a function of the strain and grain size was derived for the ECAPed *** following equation was finally obtained:σ(ε)=103.9+1825ε-9.6ε1/2·d-1/2+8.3d-1/2.

关键词： Ti mechanical properties grain size flow stress equal channel angular pressing

The Role of Relative Spinal Motion during Feline Galloping for Speed Performance

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Journal of Bionic Engineering 2014年第4期11卷 517-528页

作者： young Kook kim Jongwon Park Byungho Yoon Kyung-Soo kim Soohyun kim Robotics Program Korea Advanced Institute of Science and Technology (KAIST) Daejeon 305-701 Republic of Korea Department of Mechanical Engineering Korea Advanced Institute of Science and Technology (KAIST) Daejeon 305-701 Republic of Korea

Felines use their spinal column to increase their running speed at rapid locomotion performance. However, its motion profile behavior during fast gait locomotion has little attention. The goal of this study is to examine the relative spinal motion profile during two different galloping gait speeds. To understand this dynamic behavior trend, a dynamic motion of the feline animal （Felis catus domestica） was measured and analyzed by motion capture devices. Based on the experiments at two different galloping gaits, we observed a significant increase in speed （from 3.2 m.s-1 to 4.33 m.s-1） during the relative motion profile synchronization between the spinal （range： 118.86~ to 168.00~） and pelvic segments （range： 46.35~ to 91.13~） during the hindlimb stance phase （time interval： 0.495 s to 0.600 s）. Based on this discovery, the relative angular speed profile was applied to understand the possibility that the role of the relative motion match during high speed locomotion generates bigger ground reaction force.

关键词： feline galloping galloping gait pattern relative spinal motion speed performance phase match

Acoustic Nonlinearity of a Laser-Generated Surface Wave in a Plastically Deformed Aluminum Alloy

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Chinese Physics Letters 2012年第12期29卷 39-43页

作者： kim Chung-Seok JHANG Kyung-young Metallurgy and Materials Engineering Chosun UniversitySeosuk-dongGwangju501-759South Korea Mechanical Engineering Hanyang UniversityHangdang-dongSeongdong-guSeoul133-791South Korea

The acoustic nonlinearity of surface waves is studied to evaluate plastic deformation in aluminum alloys.A narrow-band surface wave is successfully generated by a pulsed Nd-YAG laser system consisting of a beam expander and a slit *** degrees of tensile deformation are induced by interrupting the tensile tests so as to obtain aluminum specimens with different degrees of plastic *** normalized acoustic nonlinearity increases as a function of tensile *** experimental results show that the acoustic nonlinearity of a laser-generated surface wave has a good correlation with the level of tensile deformation and has a potential to evaluate microdamage induced by dislocation microplasticity.

关键词： deformation nonlinearity Deform

Dexamethasone inhibits hypoxia-induced epithelial-mesenchymal transition in colon cancer

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World Journal of Gastroenterology 2015年第34期21卷 9887-9899页

作者： jung Ho kim You-Jin Hwang Sang Hoon Han young Eun Lee Saerom kim Yoon Jae kim Jae Hee Cho Kwang An Kwon ju Hyun kim Se-Hee kim Department of Internal Medicine Gachon University Gil Medical Center Division of Biological Science Gachon University of Medicine and Science Department of Internal Medicine Jeju National University School of Medicine Gachon Medical Research Institute Gachon University Gil Medical Center

AIM:To elucidate the effects of dexamethasone on hypoxia-induced epithelial-to-mesenchymal transition(EMT) in colon ***:Human colon cancer HCT116 and HT29 cells were exposed to normoxic(21%) and hypoxic(1%) conditions. First,the effect of dexamethasone on cell viability was examined by MTT cell proliferation assay. In order to measure the expression levels of EMT markers(Snail,Slug,Twist,E-cadherin,and integrin αVβ6) and hypoxia-related genes [Hypoxia-inducible factor-1α(HIF-1α) and vascular endothelial growth factor(VEGF)] by dexamethasone,quantitative real-time polymerase chain reaction and western blot analysis were performed. Furthermore,the morphological changes of colon cancer cells and the expression pattern of E-cadherin by dexamethasone were detected through immunocytochemistry. Finally,the effects of dexamethasone on the invasiveness and migration of colon cancer cells were elucidated using matrigel invasion,migration,and wound healing migration ***:Under hypoxia,dexamethasone treatment inhibited HIF-1α protein level and its downstream gene,VEGF m RNA level in the colon cancer cell lines,HCT116 and HT29. In addition,the presence of dexamethasone down-regulated the m RNA levels of hypoxia-induced Snail,Slug,and Twist,all transcriptional factors of EMT,as well as hypoxia-induced integrin αVβ6 protein level,a well-known EMT marker for colon cancer cells. Furthermore,reduced E-cadherin in hypoxic condition was found to be recoverable by treating with dexamethasone in both colon cancer cell lines. Similarly,under hypoxic conditions,dexamethasone restored the growth pattern and morphological phenotype reminiscent of colon cancer cells grown under normoxic conditions; dexamethasone blocked the migration and invasion of both colorectal cancer cell lines in ***:Our study suggested that dexamethasone has inhibitory effects on cell migration and invasion by suppressing EMT of colon cancer cell lines in hypoxic condition.

关键词： Dexamethasone Colon cancer Hypoxia Hypoxia-inducib

Effect of pulse time on surface characteristics and corrosion resistance during pulse electrochemical polishing

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中国有色金属学会会刊：英文版 2012年第S3期22卷 876-880页

作者： young-Bin kim Jeong-Woo PARK Department of Advanced Parts and Materials Engineering Chosun University Department of Mechanical Design Engineering Chosun University

Pulse electrochemical polishing (PECP) was used to improve the mechanical properties,such as surface roughness and corrosion resistance,of conductive metallic *** can provide a smooth,bright,reflective,and deburred surface that exhibits superior corrosion *** this work,stainless steel was used as the anode,and copper was used as the cathode due to their low electrical *** surface roughness of the PECP sample was measured by atomic force microscopy (AFM).A scanning electron microscope (SEM) was used to observe surface characteristics,and an Auger electron spectroscope (AES) was used to analyze the metallurgical composition and thickness of the passive *** aim of this research was to compare the corrosion resistance rates of the unprocessed and PECP-processed stainless steel.

关键词： stainless stell pulse electrochemical polishing corrosion resistance

Transparent Supercapacitors: From Optical Theories to Optoelectronics Applications

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Energy & Environmental Materials 2020年第3期3卷 265-285页

作者： Sang-Woo kim Sang-young Lee Department of Energy Engineering School of Energy and Chemical EngineeringUlsan National Institute of Science and Technology(UNIST)Ulsan 689-798Korea

The ever-increasing demand for smart optoelectronics spurs the relentless pursuit of transparent wireless devices as a game-changing technology that can provide unseen visual information behind the *** enable successful operation of the transparent wireless devices,their power sources should be highly transparent in addition to acquiring reliable electrochemical *** various transparent power sources,supercapacitors(SCs)have been extensively investigated as a promising candidate due to their exceptional cyclability,power capability,material diversity,and scalable/low-cost ***,we describe current status and challenges of transparent SCs,with a focus on their core materials,performance advancements,and integration with application devices.A special attention is devoted to transparent conductive electrodes(TCEs)which act as a keyenabling component in the transparent *** on fundamental understanding of optical theories and operating principles of transparent materials,we comprehensively discuss materials chemistry,structural design,and fabrication techniques of *** addition,noteworthy progresses of transparent SCs are briefly overviewed in terms of their architectural design,opto-electrochemical performance,flexibility,form factors,and integration compatibility with transparent flexible/wearable devices of ***,development direction and outlook of transparent SCs are explored along with their viable roles in future application fields.

关键词： energy storage flexibility optoelectronics transparent conductive electrodes transparent supercapacitors

Clinical significance of the leptin and leptin receptor expressions in prostate tissues

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Asian Journal of Andrology 2008年第6期10卷 923-928页

作者： jung Hoon kim Shin young Lee Soon Chul Myung young Sun kim Tae-Hyoung kim Mi Kyung kim Departments of Urology College of Medicine Chung-Ang University Seoul 140-757 Korea Departments of Pathology College of Medicine Chung-Ang University Seoul 140-757 Korea

Aim： To evaluate the expression of leptin and leptin receptor in benign prostatic hyperplasia （BPH） and prostate cancer （PCa）, and to investigate whether they are associated with the development and progression of PCa. Methods： hnmunohistochemical staining was performed to examine the expression of leptin and leptin receptor in BPH and PCa. PCa was divided into three groups： localized PCa, locally advanced PCa and metastatic PCa. The positive staining was identified and the percentage of the positive staining was graded. We also assessed the relationship between both the Gleason score and body mass index （BMI） and PCa. Results： The percentage of the leptin expression in PCa was significantly higher than that in BPH （P 〈 0.01）. For the PCa group, the expressed levels of leptin showed a considerable correlation with localized PCa and metastatic PCa （P 〈 0.05）. Leptin receptor, however, did not reveal a definite difference between BPH and PCa. The expression of leptin indicated a significant difference between well-differentiated PCa （Gleason score ≤6） and poorly differentiated PCa （Gleason score 8-10）（P 〈 0.05）. The relation between the leptin expression level in PCa and the BMI was not remarkable （P = 0.447）. Conclusion： Our results suggest that leptin might have a promoting effect on the carcinogenesis and progression of PCa.

关键词： leptin leptin receptor prostatic neoplasms

Long-term result of endoscopic Histoacryl （N-butyl-2-cyanoacrylate）injection for treatment of gastric varices

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World Journal of Gastroenterology 2011年第11期17卷 1494-1500页

作者： Eun jung Kang Soung Won Jeong Jae young Jang Joo young Cho Sae Hwan Lee Hyun Gun kim Sang Gyune kim young Seok kim young Koog Cheon young Deok Cho Hong Soo kim Boo Sung kim Institute for Digestive Research Department of Internal MedicineSoonchunhyang University College of MedicineSeoul HospitalSeoul 140-743South Korea

AIM:To evaluate the long-term efficacy and safety of endoscopic obliteration with Histoacryl  for treatment of gastric variceal bleeding and ***:Between January 1994 and March 2010 at SoonChunHyang University Hospital,a total of 127 patients with gastric varices received Histoacryl  injections *** hundred patients underwent endoscopic Histoacryl  injections because of variceal bleeding,the other 27 patients received such injections as a prophylactic ***:According to Sarin classification,56 patients were GOV1,61 patients were GOV2 and 10 patients were *** of the varices were large(F2 or F3,111 patients).The average volume of Histoacryl  per each session was 1.7±1.3 cc and mean number of sessions was 1.3±0.6.(1 session-98 patients,2 sessions-25 patients,≥3 sessions-4 patients).Twenty-seven patients with high risk of bleeding(large or fundal or RCS+or Child C) received Histoacryl  injection as a primary prophylactic *** these patients,hepatitis B virus was the major etiology of cirrhosis,25 patients showed GOV1 or 2(92.6%)and F2 or F3 accounted for 88.9%(n=24).The rate of initial hemostasis was 98.4%and recurrent bleeding within one year occurred in 18.1%of *** hemostasis during episodes of rebleeding was achieved in 73.9%of *** survival was 50 mo (95%CI 30.5-69.5).Major complications occurred in 4 patients(3.1%).The rebleeding rate in patients with hepatocellular carcinoma or GOV2 was higher than in those with other *** of the 27 subjects who were treated prophylactically experienced treatment-related *** survival rates of the 127 patients at 6 mo,1,3,and 5 years were 92.1%,84.2%,64.2%,and 45.3%,*** 6 mo cumulative survival rate of the 27 patients treated prophylactically was 75%.CONCLUSION:Histoacryl  injection therapy is an effective treatment for gastric varices and also an effective prophylactic treatment of gastric varices which

关键词： Gastric varix Prophylaxis Histoacryl  (Nbutyl-2-cyanoacrylate) Histoacryl  injection Treatment of gastric varix