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Computed tomography findings for predicting severe acute hepatitis with prolonged cholestasis

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World Journal of Gastroenterology 2013年第16期19卷 2543-2549页

作者： Sang Jung Park Jin Dong kim Yeon Seok Seo Beom Jin Park Min Ju kim Soon Ho Um chang ha kim Hyung Joon Yim Soon Koo Baik Jin Yong Jung Bora Keum Yoon Tae Jeen Hong Sik Lee Hoon Jai Chun chang Duck kim Ho Sang Ryu Department of Internal Medicine College of Medicine Korea University Department of Internal Medicine Cheju Halla General Hospital Department of Radiology College of Medicine Korea University Department of Internal Medicine Yonsei University Wonju College of Medicine Wonju Christian Hospital

AIM: To evaluate the significance of computed tomography (CT) findings in relation to liver chemistry and the clinical course of acute hepatitis. METHODS: Four hundred and twelve patients with acute hepatitis who underwent enhanced CT scanning were enrolled retrospectively. Imaging findings were analyzed for the following variables: gallbladder wall thickness (GWT), arterial heterogeneity, periportal tracking, number and maximum size of lymph nodes, presence of ascites, and size of spleen. The serum levels of alanine aminotransferase, alkaline phosphatase, bilirubin, albumin, and prothrombin time were measured on the day of admission and CT scan, and laboratory data were evaluated every 2-4 d for all subjects during hospitalization. RESULTS: The mean age of patients was 34.4 years, and the most common cause of hepatitis was hepatitis A virus (77.4%). The mean GWT was 5.2 mm. The number of patients who had findings of arterial heterogeneity, periportal tracking, lymph node enlargement > 7 mm, and ascites was 294 (80.1%), 348 (84.7%), 346 (84.5%), and 56 (13.6%), respectively. On multivariate logistic regression, male gender [odds ratio (OR) = 2.569, 95%CI: 1.477-4.469, P = 0.001], toxic hepatitis (OR = 3.531, 95%CI: 1.444-8.635, P = 0.006), level of albumin (OR = 2.154, 95%CI: 1.279-3.629, P = 0.004), and GWT (OR = 1.061, 95%CI: 1.015-1.110, P = 0.009) were independent predictive factors for severe hepatitis. The level of bilirubin (OR = 1.628, 95%CI: 1.331-1.991, P < 0.001) and GWT (OR = 1.172, 95%CI: 1.024-1.342,P = 0.021) were independent factors for prolonged cholestasis in multivariate analysis. CONCLUSION: In patients with acute hepatitis, GWT on CT scan was an independent predictor of severe hepatitis and prolonged cholestasis.

关键词： Acute hepatitis Cholestasis Computed tomography Prognosis Gallbladder

Aligned Ion Conduction Pathway of Polyrotaxane‑Based Electrolyte with Dispersed Hydrophobic Chains for Solid‑State Lithium–Oxygen Batteries

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Nano-Micro Letters 2025年第2期17卷 169-186页

作者： Bitgaram kim Myeong‑chang Sung Gwang‑Hee Lee Byoungjoon Hwang Sojung Seo Ji‑Hun Seo Dong‑Wan kim Department of Materials Science and Engineering Korea University145 Anam‑RoSeongbuk‑GuSeoul 02841Republic of Korea School of Civil Environmental and Architectural EngineeringKorea University145 Anam‑RoSeongbuk‑GuSeoul 02841Republic of Korea Materials Science and Chemical Engineering Center Institute for Advanced Engineering(IAE)Yongin 17180Republic of Korea

A critical challenge hindering the practical application of lithium–oxygen batteries(LOBs)is the inevitable problems associated with liquid electrolytes,such as evaporation and safety *** study addresses these problems by proposing a modified polyrotaxane(mPR)-based solid polymer electrolyte(SPE)design that simultaneously mitigates solvent-related problems and improves ***-SPE exhibits high ion conductivity(2.8×10^(−3)S cm^(−1)at 25℃)through aligned ion conduction pathways and provides electrode protection ability through hydrophobic chain *** this mPR-SPE into solid-state LOBs resulted in stable potentials over 300 *** situ Raman spectroscopy reveals the presence of an LiO_(2)intermediate alongside Li_(2)O_(2)during oxygen *** situ X-ray diffraction confirm the ability of the SPE to hinder the permeation of oxygen and moisture,as demonstrated by the air permeability *** present study suggests that maintaining a low residual solvent while achieving high ionic conductivity is crucial for restricting the sub-reactions of solid-state LOBs.

关键词： Solid polymer electrolyte Lithium-oxygen batteries Polyrotaxane ion conductivity Hydrophobic chain

Surface properties of Al-doped ZnO thin film before and after CF_4/Ar plasma etching

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Plasma Science and Technology 2022年第7期24卷 194-200页

作者： Young-Hee JOO Gwan-ha kim Doo-Seung UM chang-Il kim School of Electrical and Electronics Engineering Chung-Ang UniversitySeoul 06974Republic of Korea Department of Semiconductor Materials and Applications Korea PolytechnicSeongnam 13122Republic of Korea Department of Electrical Engineering Sejong UniversitySeoul 05006Republic of Korea

Al-doped ZnO(AZO) is considered as an alternative to transparent conductive oxide *** and achieving a stable surface are important challenges in the development and optimization of dry etching processes, which must be overcome for the application of AZO in various devices. Therefore, in this study, the etch rate and surface properties of an AZO thin film after plasma etching using the adaptive coupled plasma system were investigated. The fastest etch rate was achieved with a CF_(4)/Ar ratio of 50:50 sccm. Regardless of the ratio of CF_(4) to Ar,the transmittance of the film in the visible region exceeded 80%. X-ray photoelectron spectroscopy analysis of the AZO thin film confirmed that metal-F bonding persists on the surface after plasma etching. It was also shown that F eliminates O vacancies. Consequently, the work function and bandgap energy increased as the ratio of CF-4 increased. This study not only provides information on the effect of plasma on AZO thin film, but identifies the cause of changes in the device characteristics during device fabrication.

关键词： Al-doped ZnO plasma etching F-based plasma surface characteristics X-ray photoelectron spectroscopy ultraviolet photoelectron spectroscopy

Experimental Investigation of Flexible hawkmoth-like Wings on the Wing-wake Interaction in Hovering Flight

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Journal of Bionic Engineering 2018年第1期15卷 139-153页

作者： YeongGyun Ryu Jo Won chang Joon Chung Dong-ha kim Department of Aerospace Engineering Ryerson University Toronto Ontario M5B 2K3 Canada Department of Aeronautical Science and Flight Operation Korea Aerospace University 76 Hanggongdaehak-ro Deogyang-gu Goyang-si Gyeonggi-do 10540 Republic of Korea Aerodynamics Group Korean Air R&D Center Daejeon Metropolitan City 34054 Republic of Korea

To study wing-wake interaction for various wing flexibilities, force measurements and digital particle image velocimetry were carried out on flapping hawkmoth-like wings in a water tank. Wing thickness was employed as a design variable for the wing flexi- bility distributions. Abrupt flap-down and phase delay in flexible wings influenced the behaviors of the Leading-Edge Vortex （LEV） and Trailing-Edge Vortex （TEV）, generated by the previous stroke. While the rigid wing exhibited a detached LEV at the end of the stroke, wing with specific flexibilities obtained attached LEVs. The attached LEVs induced a relatively rapid flow toward the wing surface as a result of encountering the TEV, and the flow caused a higher lift peak. On the other hand, the wings with larger wing deformations generated distinctive changes in LEV and TEV behaviors. The flap-down helped the TEV form closer to the wing surface, and it thus caused a downwash rather than wing-wake interaction. Furthermore, the most flexible wing had a newly-formed pair of LEVs above the wing during the wing reversal, thereby being not able to generate the wing-wake interaction. These results help to understand the different vortex structures generated by flexible wings during the wing reversal and the corresponding effects of wing-wake interaction.

关键词： hovering flight flexible hawkmoth wings wing-wake interaction Digital Particle Image Velocimetry (DPIV)

Effect of Al addition on corrosion behavior of high-purity Mg in terms of processing history

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Journal of Magnesium and Alloys 2023年第3期11卷 851-868页

作者： Sang Kyu Woo Byeong-Chan Suh ha Sik kim chang Dong Yim Helmholtz Zentrum Hereon Max-Planck-Straße 1Geesthacht D-21502Germany Korea Institute of Materials Science 797 Changwondae-roSeongsan-guChangwonGyeongnam 51508Republic of Korea University of Science and Technology 217 Gajeong-roYuseong-guDaejeon 34113Republic of Korea

In this study,the effects of Al addition on the corrosion behavior of pure Mg with controlled impurity contents were systematically analyzed according to the processing *** results revealed that the corrosion behavior of high-purity Mg-Al alloys is strongly related to changes in the microstructure,including theβphase and Al-Mn or Al-Fe phases,and the protectiveness of the surface film according to the Al content and processing *** the as-cast alloys,the corrosion rate increased due to the increase ofβphase as the Al content increased,but in the as-extruded alloys,the corrosion rate,which was high due to intermetallic compounds caused by impurities in the low Al alloy,decreased as the Al content increased,and then increased *** is due to the combined effect of the increase of theβphase and decrease of the impurity effect,and the increase of the dissolved Al *** results suggest that it is necessary to analyze the effect of alloying elements on the corrosion behavior of pure Mg with information concerning the impurity content and processing history.

关键词： Mg High purity Mg-Al alloys Processing history Micro-galvanic Surface film

Crystal structure of Arabidopsis thaliana RabA_(1a)

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Journal of Integrative Plant Biology 2019年第2期61卷 93-109页

作者： Ji-Sook Yun Sung Chul ha Shinae kim Yeon-Gil kim Hyeran kim Jeong Ho chang Department of Biology Education Kyungpook National University Beamline Science Division Pohang Accelerator Laboratory Department of Biological Sciences Kangwon National University

RabGTPase is a member of the Ras superfamily of small GTPases, which share a GTP-binding pocket containing highly conserved motifs that promote GTP hydrolysis. In Arabidopsis, the RabA group, which corresponds to the Rab_(11) group in animals, functions in the recycling of endosomes that control docking and fusion during vesicle transport. However, their molecular mechanisms remain unknown. In this study, we determined the crystal structures of the GDP-bound inactive form and both GppNHp-and GTP-bound active forms of RabA1a, at resolutions of 2.8, 2.6, and 2.6 A?,respectively. A bound sulfate ion in the active site of the GDP-bound structure stabilized Switch Ⅱ by bridging the interaction between a magnesium ion and *** of the two states of RabA1a with Rab_(11) proteins revealed clear differences in the Switch Ⅰ and Ⅱ loops. These results suggested that conformational change of the Switch regions of RabA1a, derived by GTP or GDP binding, could maintain subcellular membrane traffic through the specific interaction of effector molecules.

关键词： GDP Crystal structure of Arabidopsis thaliana RabA Figure

Panax ginseng induces the expression of CatSper genes and sperm hyperactivation

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Asian Journal of Andrology 2014年第6期16卷 845-851页

作者： Eun Hwa Park Do Rim kim ha Young kim Seong Kyu Park Mun Seog chang Department of Prescriptionology College of Korean Medicine Kyung Hee Unversity Seoul Korea.

The cation channel of sperm （CatSper） protein family plays important roles in male reproduction and infertility. The four members of this family are expressed exclusively in the testis and are localized differently in sperm. To investigate the effects of Panax ginseng treatment on the expression of CatSper genes and sperm hyperactivation in male mice, sperm motility and CatSper gene expression were assessed using a computer-assisted semen analysis system, a Fluoroskan Ascent microplate fluorometer to assess Ca2＊ influx, *** polymerase chain reaction, Western blotting and immunofluorescence. The results suggested that the Ca2＊ levels of sperm cells treated with P. ginseng were increased significantly compared with the normal group. The P. ginseng-treated groups showed increased sperm motility parameters, such as the curvilinear velocity and amplitude of lateral head displacement. Taken together, the data suggest that CatSper messenger ribonucleic acid levels were increased significantly in mouse testes in the P. ginseng-treated group, as was the protein level, with the exception of CatSper2. In conclusion, P. ginseng plays an important role in improving sperm hyperactivation via CatSper gene expression.

关键词： Ca2+ CatSper hyperactivation panax Einseng

Two Types of Diurnal Variations in Heavy Rainfall during July over Korea

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Advances in Atmospheric Sciences 2021年第12期38卷 2201-2211页

作者： chang-Kyun PARK Minhee chang chang-Hoi HO Kyung-Ja ha Jinwon kim Byung-Ju SOHN School of Earth and Environmental Sciences Seoul National UniversitySeoul 08826Korea School of Earth and Environmental Systems Pusan National UniversityBusan 46241Korea Center for Climate Physics Institute for Basic ScienceBusan 46241Korea National Institute of Meteorological Sciences Korean Meteorological AdministrationJeju 63568Korea

This study examined the characteristics of the diurnal variations of heavy rainfall(≥110 mm in 12 hours)in Korea and the related atmospheric circulation for July from 1980−*** the analysis period,two dominant pattens of diurnal variation of the heavy rainfall emerged:all-day heavy rainfall(AD)and morning only heavy rainfall(MO)*** the AD-type,the heavy rainfall is caused by abundant moisture content in conjunction with active convection in the morning(0000−1200,LST;LST=UTC+9)and the afternoon hours(1200−2400 LST).These systems are related to the enhanced moisture inflow and upward motion induced by the strengthening of the western North Pacific subtropical high and upper-tropospheric *** the MO-type,heavy rainfall occurs mostly in the morning hours;the associated atmospheric patterns are similar to the *** find that the atmospheric pattern related to severe heavy rainfalls in 2020 corresponds to a typical AD-type and resembles the 1991 heavy-rainfall system in its overall synoptic/mesoscale *** present results imply that extremely heavy rainfall episodes in Korea during the 2020 summer may occur again in the future associated with the recurring atmospheric phenomenon related to the heavy rainfall.

关键词： heavy rainfall diurnal cycle of rainfall 2020 summer summer rainy season Korea

Comparative study on discharge conditions in micro-hole electrical discharge machining of tungsten carbide (WC-Co) material

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中国有色金属学会会刊：英文版 2009年第B9期19卷 114-118页

作者： Hyun-Seok TAK chang-Seung ha Dong-Hyun kim Ho-Jun LEE hae-June LEE Myung-chang KANG National Core Research Center for Hybrid Materials Solution Pusan National University Department of Electrical Engineering Pusan National University

WC-Co is used widely in die and mold industries due to its unique combination of hardness, strength and wear-resistance. For machining difficult-to-cut materials, such as tungsten carbide, micro-electrical discharge machining(EDM) is one of the most effective methods for making holes because the hardness is not a dominant parameter in EDM. This paper describes the characteristics of the discharge conditions for micro-hole EDM of tungsten carbide with a WC grain size of 0.5 μm and Co content of 12%. The EDM process was conducted by varying the condenser and resistance values. A R-C discharge EDM device using arc erosion for micro-hole machining was suggested. Furthermore, the characteristics of the developed micro-EDM were analyzed in terms of the electro-optical observation using an oscilloscope and field emission scanning electron microscope.

关键词：电火花加工碳化钨钴难切削材料硬质合金放电扫描电子显微镜微孔模具行业