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Interactions between Transmembrane Helices within Monomers of the Aquaporin AtPIP2;1 Play a Crucial Role in Tetramer Formation

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Molecular Plant 2016年第7期9卷 1004-1017页

作者： Yun-Joo Yoo Hyun Kyung Lee Wonhee Han Dae Heon Kim Myoung Hui Lee Jouhyun Jeon Dong Wook Lee Junho Lee Yongjik Lee Juhun Lee Jin seok Kim Yunje cho Jin-Kwan Han Inhwan Hwang School of Interdisciplinary Bioscience and Bioengineering Pohang University of Science and Technology Pohang 790-784 Korea Department of Life Sciences Pohang University of Science and Technology Pohang 790-784 Korea Department of Biology Sunchon National University Sunchon 57922 Korea Division of Integrative Biosciences and Biotechnology Pohang University of Science and Technology Pohang 790-784 Korea

Aquaporin （AQP） is a water channel protein found in various subcellular membranes of both prokaryotic and eukaryotic cells. The physiological functions of AQPs have been elucidated in many organisms. However, understanding their biogenesis remains elusive, particularly regarding how they assemble into tetramers. Here, we investigated the amino acid residues involved in the tetramer formation of the Arabidopsis plasma membrane AQP AtPIP2;1 using extensive amino acid substitution mutagenesis. The mutant proteins V41A/ E44A, F51A/L52A, F87A/191A, F92A/193A, V95A/Y96A, and H216A/L217A, harboring alanine substitutions in the transmembrane （TM） helices of AtPIP2;1 polymerized into multiple oligomeric complexes with a vari- able number of subunits greater than four. Moreover, these mutant proteins failed to traffic to the plasma membrane, instead of accumulating in the endoplasmic reticulum （ER）. Structure-based modeling revealed that these residues are largely involved in interactions between TM helices within monomers. These results suggest that inter-TM interactions occurring both within and between monomers play crucial roles in tetramer formation in the AtPIP2;1 complex. Moreover, the assembly of AtPIP2;1 tetramers is critical for their trafficking from the ER to the plasma membrane, as well as water permeability.

关键词： aquaporin AtPIP2 tetramer formation interaction between transmembrane helices

Efficient and power-awareness query over sensor networks

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重庆邮电大学学报（自然科学版） 2007年第3期19卷 270-275页

作者： Sang-Hun Eo Ho-seok Kim Sook-Kyoung cho Hae-Young Bae Dept. of Computer Science & Information Engineering Inha University

Sensor networks consisted of low-cost, low-power, multifunctional miniature sensor devices have played an important role in our daily life. Light and humidity monitoring, seismic and animal activity detection, environment and habitat monitoring are the most common applications. However, due to the limited power supply, ordinary query methods and algorithms can not be applied on sensor networks. Queries over sensor networks should be power-aware to guarantee the maximum power savings. The minimal power consumption by avoiding the expensive communication of the redundant sensor nodes is concentrated on. A lot of work have been done to reduce the participated nodes, but none of them have considered the overlapping minimum bounded rectangle (MBR) of sensors which make them impossible to reach the optimization solution. The proposed OMSI-tree and OMR algorithm can efficiently solve this problem by executing a given query only on the sensors involved. Experiments show that there is an obvious improvement compared with TinyDB and other spatial index, adopting the proposed schema and algorithm.

关键词：传感器网络查询最小界矩形效率

Multi-objective Optimization Based on Unsteady Analysis Considering the Efficiency and Radial Force of a Single-Channel Pump for Wastewater Treatment

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Journal of Mechanics Engineering and Automation 2016年第5期6卷 234-245页

作者： Jin-Hyuk Kim Bo-Min cho Yotmg-seok choi Kyotmg-Yong Lee Thermal & Fluid System R&D Group Korea Institute of lndustrial Technology Cheonan Republic of Korea Advanced Energy and Technology University of Science and Technology Daejeon Republic of Korea

A multidisciplinary optimization was conducted to simultaneously improve the efficiency and reduce the radial force of a single-channel pump for wastewater treatment. A hybrid multi-objective evolutionary algorithm was coupled with a surrogate model to optimize the geometry of the single-channel pump volute. Steady and unsteady Reynolds-averaged Navier-Stokes equations with a shear stress transport turbulence model were discretized using finite volume approximations and were then solved on tetrahedral grids to analyze the flow in the single-channel pump. The three objective functions represented the total efficiency, the sweep area of the radial force during one revolution, and the distance of the mass center of sweep area from the origin while the two design variables were related to the cross-sectional area of the internal flow of the volute. Latin hypercube sampling was employed to generate twelve design points within the design space, and response surface approximation models were constructed as surrogate models for the objectives based on the values of the objective function at the given design points. A fast non-dominated sorting genetic algorithm for local search was coupled with the surrogate models to determine the global Pareto-optimal solutions. The trade-off between the objectives was determined and was described in terms of the Pareto-optimal solutions. The results of the multi-objective optimization showed that the optimum design simultaneously improved the efficiency and reduced the radial force relative to those of the reference design.

关键词： Single-channel pump efficiency radial force sweep area unsteady analysis optimization.

Effects of High CO_2 Pretreatment on the Quality of Fresh-Cut Potatoes

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Journal of Food Science and Engineering 2014年第5期4卷 219-227页

作者： Hye-Jin choi Jeong-seok cho Hun-Sik Chung Kwang-Deog Moon Department of Food Science and Technology Kyungpook National University Daegu 702-701 Korea Department of Food Science and Technology Pusan National University Gyeongnam 627-706 Korea Food and Bio-Industry Research Institute Kyungpook National University Daegu 702-701 Korea

Effects of short-term high CO_2 pretreatment on quality of fresh-cut potatoes were studied. Potatoes were treated under 90% CO_2 for 18 h, peeled, cut, dipped in 1% ascorbic acid or distilled water for 3 min, packed in polyethylene bags and stored for 12 d at 4 ℃. Non-treated potatoes were used as the control. High CO2 pretreatments ensured maintenance of a high level of CO_2 in headspace of packages containing fresh-cut potatoes. Both the growth of total aerobic bacteria in initial stages of post-cut storage and browning index of the cut surface were lower in high CO_2 treated cut potato. Anti-browning effect of high CO_2 pretreatment was decreased when applied in combination with ascorbic acid. Soluble solids, pH, titratable acidity and flesh firmness of fresh-cut potatoes were not affected by high CO_2 treatment. Therefore, high CO_2 treatment before slicing could be effective method to maintain quality of flesh-cut potatoes.

关键词： Potatoes flesh cut CO_2 ascorbic acid browning.

Evaluation of the Surface of Nitinol after MR Polishing Process

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Journal of Applied Mathematics and Physics 2015年第2期3卷 208-217页

作者： Byung-Chan Kim Jung-Won Lee seok-Jae Ha Yong-Kyu cho Dong-Sung Kang Myeong-Woo cho Department of Mechanical Engineering Inha University Incheon Republic of Korea WISYS Gunpo-si Republic of Korea

Nitinol is used in various industries, especially for biomaterials. Generally, the surface integrity of sub-micron level and non-surface flaw is required in nitinol for biomaterial. However, surface flaws, such as scratches, pits, and residual stress, can occur on the polished surface, and it is difficult to remove these surface flaws. The corrosion is accelerated continuously and causes bad influence in the body. Therefore, in this study, conventional polishing and MR polishing were used to minimize the corrosion and residual stress when the nitinol is used as biomaterial. X-ray diffraction and Tafel extrapolation were used to investigate the residual stress and the corrosion, and the strain hardening was investigated by nanoindentation. Surface integrities were also evaluated by SEM image and surface roughness results. As a result, the increased residual stress in conventional polishing was decreased by MR polishing. The result of corrosion test was improved from ?301 mV to ?280 mV. The residual stress was improved from ?38.18 MPa to ?31.17 MPa. Finally, it is certified that MR polishing can be used to minimize surface flaws and to improve the corrosion properties.

关键词： Nitinol MR Polishing Corrosion Test Residual Stress Strain Hardening

Helicobacter pylori in middle ear of children with

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Chinese Medical Journal 2011年第24期 4275-4278页

作者： PARK Chul-won CHUNG Jae-ho MIN Hyun-jung KIM Kyung-rae TAE Kyung cho seok-hyun LEE Seung-hwan Department of Otolaryngology-Head and Neck Surgery School ofMedicine Hanyang University Seoul Korea

Background Otitis media with effusion （OME） is a common pediatric disease, but its pathogenesis remains uncertain. The relationship between OME and Helicobacter pylori （HP） is currently being studied, and a relationship has not yet been confirmed. The purpose of this study was to show that a relationship does exist between HP and OME. Methods The study consisted of 60 patients who were diagnosed with OME and had ventilation tube insertions with or without an adenoidectomy. This study included an additional 30 patients who had only received an adenoidectomy without being diagnosed with OME. The effusion samples were analyzed with polymerase chain reaction （PCR） and the campylobacter-like organism （CLO） test. The adenoid tissue samples were analyzed with the CLO test. Results Eighteen patients among the 60 patients （30%） tested positive for HP. In the cases with adenoids, 15.6% of the OME patients and 13.3% of the adenoidectomy only patients were positive for HP. There were no differences between the prevalence of HP in the adenoids of OME patients and the patients without OME. Conclusion HP can be considered one of the causes of OME.

关键词： Helicobacter pylori otitis media effusion

Hepatocellular carcinoma,decompensation,and mortality based on hepatitis C treatment:A prospective cohort study

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World Journal of Gastroenterology 2022年第30期28卷 4182-4200页

作者： Gwang Hyeon choi Eun Sun Jang Young seok Kim Youn Jae Lee In Hee Kim Sung Bum cho Han Chu Lee Jeong Won Jang Moran Ki Hwa Young choi Dahye Baik Sook-Hyang Jeong Department of Internal Medicine Seoul National University Bundang HospitalSeoul National University College of MedicineSeongnam 13620South Korea Department of Internal Medicine Soonchunhyang University Bucheon HospitalBucheon 14584South Korea Department of Internal Medicine Inje University Busan Paik HospitalBusan 47392South Korea Department of Internal Medicine Chonbuk National University HospitalJeonju 54907JeonbukSouth Korea Department of Internal Medicine Chonnam National University Hwasun HospitalHwasun 58128South Korea Department of Gastroenterology Asan Medical CenterUniversity of Ulsan College of MedicineSeoul 05505South Korea Department of Internal Medicine The Catholic University of KoreaSeoul 06591South Korea Cancer Control and Population Health Graduate School of Cancer Science and PolicyNational Cancer CenterGoyang 10408South Korea

BACKGROUND Prospective studies of the long-term outcomes of patients with hepatitis C virus(HCV)infection after treatment with interferon-based therapy(IBT)or directacting antivirals(DAA)are limited in many Asian *** To elucidate the incidences of hepatocellular carcinoma(HCC)and death/transplantation based on treatment with IBT or DAA,to compare the outcomes of the sustained virologic response(SVR)to IBT and DAA,and to investigate outcome-determining factors after *** This cohort included 2054 viremic patients(mean age,57 years;46.5%male;27.4%with cirrhosis)prospectively enrolled at seven hospitals between 2007 and *** were classified as the untreated group(n=619),IBT group(n=578),and DAA group(n=857).Outcomes included the incidences of HCC and death/*** incidences of the outcomes for each group according to treatment were calculated using an exact method based on the Poisson distribution.A multivariate Cox regression analysis was performed to determine the factors associated with HCC or death/transplantation,followed by propensity score matching to confirm the *** During a median of 4.1 years of follow-up,HCC and death/transplantation occurred in 113 and 206 patients,respectively,in the entire *** with the untreated group,the incidences of HCC and death/transplantation were significantly lower in the IBT group[adjusted hazard ratio(aHR)0.47,95%CI:0.28-0.80 and aHR 0.28,95%CI:0.18-0.43,respectively]and the DAA group(aHR 0.58,95%CI:0.35-0.96,and aHR 0.19,95%CI:0.20-0.68,respectively).Among 1268 patients who attained SVR with IBT(n=451)or DAA(n=816),the multivariable-adjusted analysis showed no differences in the risks of HCC(HR 2.03;95%CI:0.76-5.43)and death/transplantation(HR 1.38;95%CI:0.55-3.49)between the two *** was confirmed by a propensity score-matching *** factors for HCC after SVR were age,genotype 1,and the presence of *** Treatment and achieving SVR

关键词： Hepatitis C virus Direct-acting antiviral Sustained virologic response Hepatocellular carcinoma Mortality

Timing of upper gastrointestinal endoscopy does not influence short-term outcomes in patients with acute variceal bleeding

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World Journal of Gastroenterology 2018年第44期24卷 5025-5033页

作者： Jeong-Ju Yoo Young Chang Eun Ju cho Ji Eun Moon Sang Gyune Kim Young seok Kim Yun Bin Lee Jeong-Hoon Lee Su Jong Yu Yoon Jun Kim Jung-Hwan Yoon Department of Gastroenterology and Hepatology Soonchunhyang University school of Medicine Bucheon 14584 South Korea Department of Internal Medicine and Liver Research Institute Seoul National University College of Medicine Seoul 03080 South Korea Department of Biostatistics Clinical Trial Center Soonchunhyang University Bucheon Hospital Bucheon 14584 South Korea

AIM To examine the association between the timing of endo-scopy and the short-term outcomes of acute variceal bleeding in cirrhotic *** This retrospective study included 274 consecutive patients admitted with acute esophageal variceal bleeding of two tertiary hospitals in Korea. We adjusted confounding factors using the Cox proportional hazards model and the inverse probability weighting （IPW） method. The primary outcome was the mortality of patients within 6 *** A total of 173 patients received urgent endoscopy （ i.e. , ≤ 12 h after admission）, and 101 patients received non-urgent endoscopy （〉 12 h after admission）. The 6-wk mortality rate was 22.5% in the urgent endoscopy group and 29.7% in the non-urgent endoscopy group, and there was no significant difference between the two groups before （P = 0.266） and after IPW （P = 0.639）. The length of hospital stay was statistically different between the urgent group and non-urgent group （P = 0.033）; however, there was no significant difference in the in-hospital mortality rate between the two groups （8.1%vs 7.9%, P = 0.960）. In multivariate analyses, timing of endoscopy was not associated with 6-wk mortality （hazard ratio, 1.297; 95% confdence interval, 0.806-2.089; P = 0.284）.CONCLUSION In cirrhotic patients with acute variceal bleeding, the timing of endoscopy may be independent of short-term mortality.

关键词： Cirrhosis Endoscopy Upper gastrointestinal bleeding Gastroesophageal varices Timing

Comparison of a novel bedside portable endoscopy device with nasogastric aspiration for identifying upper gastrointestinal bleeding

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World Journal of Gastroenterology 2014年第25期20卷 8221-8228页

作者： Jong Hwan choi Jae Hyuk choi Yoo Jin Lee Hyung Ki Lee Wang Yong choi Eun Soo Kim Kyung Sik Park Kwang Bum cho Byoung Kuk Jang Woo Jin Chung Jae seok Hwang Division of Gastroenterology and Hepatology Department of Internal Medicine Keimyung University School of MedicineDaegu 700-712South Korea

AIM: To compare outcomes using the novel portable endoscopy with that of nasogastric (NG) aspiration in patients with gastrointestinal bleeding.

关键词： Endoscopy Gastrointestinal bleeding Nasogastric aspiration