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Triterpenoid inducers of Nrf2 signaling as potential therapeutic agents in sickle cell disease： a review

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Frontiers of Medicine 2015年第1期9卷 46-56页

作者： Amma Owusu-Ansah sung Hee choi Agne Petrosiute j.hn j. Letterio Alex Yee-Chen Huang Division of Pediatric Hematology-Oncology Department of Pediatrics Case Western Reserve University School of Medicine Cleveland OH 44106 USA The Angie Fowler Adolescent & Young Adult Cancer Institute at University Hospitals Rainbow Babies & Children 's Hospital Cleveland OH 44106 USA

Sickle cell disease （SCD） is an inherited disorder of hemoglobin in which the abnormal hemoglobin S polymerizes when deoxygenated. This polymerization of hemoglobin S not only results in hemolysis and vaso- occlusion but also precipitates inflammation, oxidative stress and chronic organ dysfunction. Oxidative stress is increasingly recognized as an important intermediate in these pathophysiological processes and is therefore an important target for therapeutic intervention. The transcription factor nuclear erythroid derived- 2 related factor 2 （Nrf2） controls the expression of anti-oxidant enzymes and is emerging as a protein whose function can be exploited with therapeutic intent. This review article is focused on triterpenoids that activate Nrf2, and their potential for reducing oxidative stress in SCD as an approach to prevent organ dysfunction associated with this disease. A brief overview of oxidative stress in the clinical context of SCD is accompanied by a discussion of several pathophysiological mechanisms contributing to oxidative stress. Finally, these mechanisms are then related to current management strategies in SCD that are either utilized currently or under evaluation. The article concludes with a perspective on the potential of the various therapeutic interventions to reduce oxidative stress and morbidity associated with SCD.

关键词： oxidative stress Nrf2 triterpenoids sickle cell disease vaso-occlusion CDDO-Me

Three-Dimensional Numerical Model for Tsunami Propagation Passing Through An Obstacle

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China Ocean Engineering 2006年第3期20卷 509-516页

作者： sung j.n HONG Byung Ho choi Fumihiko IMAMURA Department of Civil and Environmental Engineering Sungkyunkwan University Chunchun-dong 300 Jangan-gu Suwon 440-746 Korea Disaster Control Research Center Graduate School of Engineering Tohoku University Aoba 06 Sendai 980-8579 Japan

A three-dimensional numerical tsunami model is developed to analyze the nonlinear behavior of flow around obstacles with the Marker and Cell （MAC） method based on the Navier-Stokes equations. Tnrough a comparison with experimental data for the cases of dam break and solitary wave propagation, verification of the three-dimensional numerical model is given. Numerical experiment is performed for the analysis of the nonlinear behavior of flow around obstacles and compared with experimental data. The velocity and pressure around obstacles are presented with sufficient accuracy for tstmami propagation passing through an obstacle.

关键词： three-dimensional numericxtl model tsunami Navier-Stokes equations Marker and Ceml (MAC) method

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j.urnal of Materials Science & Technology 2022年第16期111卷 99-110页

作者： Vioni Dwi Sartika Won Seok choi Gwanghyo choi j.ewook Han sung-j.n Chang Won-Seok Ko Blazej.Grabowski Pyuck-Pa choi Department of Materials Science and Engineering Korea Advanced Institute of Science and TechnologyDaejeon 34141Republic of Korea Gangwon Regional Division Korea Institute of Industrial TechnologyGangwon 25440Republic of Korea Division of Measurement and Analysis National Nanofab CenterDaejeon 34141Republic of Korea School of Materials Science and Engineering University of UlsanUlsan 44610Republic of Korea Institute for Materials Science University of StuttgartPfaffenwaldring 5570569 StuttgartGermany

We report laser cladding of pure titanium on a CoCrMo alloy using directed energy *** electron microscopy,the microstructural evolution upon varying the process parameters,especially laser power and powder feed rate,was investigated in relation to crack *** layers showing dilution rates of more than 5%contained cracks due to the formation of the brittle Co_(2)Ti intermetallic *** observed cracks could be ascribed to a mismatch in thermal expansion and a resulting stress of more than 440 MPa acting on the Co_(2)Ti phase,as determined by density functional theory and ***,an excess laser energy caused chemical inhomogeneity and unmelted Ti powder particles,while a deficient laser energy resulted in a lack of *** cracks nor partially melted powders were observed for a powder feed rate of 3 g/min and a laser power of 225–300 W,for which the dilution rate was minimized to less than 5%.For such samples,the cladding layers comprised pureα-Ti and a uniform CoT i interface with Co_(2)Ti islands.

关键词： Additive manufacturing Dissimilar metal j.ining Titanium Cobalt-based alloy

Coastal landscape evolution tracked from late Holocene wave-cut benches in the Sinan Archipelago,Southwest Korea

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Geoscience Frontiers 2020年第1期11卷 293-301页

作者： sung-j. choi Bokchul Kim Yong Sik Gihm Sanghoon Kwon Geology Division Korea Institute of Geoscience and Mineral ResourcesDaejeon34132Republic of Korea Department of Earth System Sciences Yonsei UniversitySeoul03722Republic of Korea School of Earth Sciences The Ohio State UniversityColumbusOH43210USA

Glacio-isostatic adj.stment(GIA)and tectonic activity are important factors in the formation of marine *** Holocene wave-cut benches in the eastern part of the West Sea of Korea,also called the Yellow Sea,can be divided into two steps:531 cm above sea level(ASL)for the upper bench(T2)and 464-481 cm ASL for the lower bench(T1).Sediments on the benches a re classified into four units,and are interpreted to be beach deposits acco rding to gravel shape,textu re,and seaward *** ove rlying sediment indicates that T2 was formed at approximately 530 cm ASL before 2900 yr BP,and T1 at approximately 460-480 cm ASL before 1520 yr *** Holocene(4000-2000 yr BP)relative sea level(RSL)curves based on GIA models are inconsistent with the wave-cut bench *** T1 and T2 benches to the RSL curves of the West Sea,the upper and the lower benches were uplifted by approximately 5-8 m and 4-7 m,*** the area is several hundred kilometers away from plate boundaries,the high frequency of earthquakes in the West Sea may have induced the uplift of wave-cut benches during the last 2000 *** indicate that the west coast of the Korean Peninsula(KP)should no longer be considered an area of subsidence,but be assigned to a regime of uplift during the late Holocene.

关键词： West Sea of Korea Yellow Sea Late Holocene Wave-cut benches Beach sediment Uplift Tectonics

Increasing sulfur utilization in lithium-sulfur batteries by a Co-MOF-74@MWCNT interlayer

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j.urnal of Energy Chemistry 2021年第9期30卷 186-193页

作者： SiHyeon sung Byung Hyuk Kim SeungTaek Lee Sanghyeon choi Woo Young Yoon Department of Materials Science and Engineering Korea University15GaAnam-dongSungbuk-GuSeoul 136-701Republic of Korea

To improve lithium-sulfur battery performance,Co-MOF-74 has been applied for the first time as an interlayer with multiwalled carbon nanotubes(MWCNTs).Co-MOF-74@MWCNT was synthesized using a solvothermal *** fabrication of Co-MOF-74@MWCNT was confirmed by scanning electron microscopy,X-ray diffraction,thermogravimetric analysis,and Brunauer-Emmett-Teller *** interlayer was fabricated using a filtration *** batteries were prepared using a CoMOF-74@MWCNT interlayer and an MWCNT interlayer and subsequently investigated via cyclic voltammetry ***-MOF-74 promotes a redox reaction and shows a small peak at 1.85 V.A symmetric and full cell test revealed that the Co-MOF-74@MWCNT cell enables a faster redox reaction and higher capacity than that of the MWCNT *** 15 cycles,the Co-MOF-74@MWCNT cell achieved a value of 1112 mAh g^(-1),which is 26% greater than that of the MWCNT cell(880 mAh g^(-1)) at 0.2 *** profile testing showed that the reason for the higher capacity of the Co-MOF-74@MWCNT cell is that it promotes the conversion of Li_(2)S_(2) to Li_(2)*** electrochemical analyses confirmed that the Co-MOF-74@MWCNT interlayer acts not only as a physical and chemical barrier but also promotes the transformation of Li_(2)S_(2) to Li_(2)S.

关键词： Li-S battery Shuttling effect Interlayer Sulfur utilization Co-MOF-74

CO2/CH4 separation using inside coated thin film composite hollow fiber membranes prepared by interfacial polymerization

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Chinese j.urnal of Chemical Engineering 2017年第3期25卷 278-287页

作者： Eun-sung j. Xinghai An Pravin G.Ingole Won-Kil choi Yeong-sung Park Hyung-Keun Lee Korea Institute of Energy Research(KIER) 71-2 Jang-dongYuseong-guDaejeon 205343Republic of Korea Department of Environmental Engineering Daejeon UniversityDaejeonRepublic of Korea Department of Advanced Energy and Technology University of Science and Technology(UST)217 Gajeong-roYuseong-guDaejeon 305-350Republic of Korea

Carbon dioxide(CO_2) is greenhouse gas which originates primarily as a main combustion product of biogas and landfill gas. To separate this gas, an inside coated thin film composite(TFC) hollow fiber membrane was developed by interfacial polymerization between 1,3–cyclohexanebis–methylamine(CHMA) and trimesoyl chloride(TMC). ATR-FTIR, SEM and AFM were used to characterize the active thin layer formed inside the PSf hollow fiber. The separation behavior of the CHMA-TMC/PSf membrane was scrutinized by studying various effects like feed gas pressure and temperature. Furthermore, the influence of CHMA concentration and TMC concentration on membrane morphology and performance were investigated. As a result, it was found that mutually the CHMA concentration and TMC concentration play key roles in determining membrane morphology and performance. Moreover, the CHMA-TMC/PSf composite membrane showed good CO_2/CH_4 separation performance. For CO_2/CH_4 mixture gas(30/70 by volume) test, the membrane(PD1 prepared by CHMA 1.0% and TMC 0.5%) showed a CO_2 permeance of 25 GPU and the best CO_2/CH_4 selectivity of 28 at stage cut of 0.1. The high CO_2/CH_4 separation performance of CHMA-TMC/PSf thin film composite membrane was mostly accredited to the thin film thickness and the properties of binary amino groups.

关键词： Thin-film composite hollow fiber membrane Interfacial polymerization CHMA/TMC CO2/CH4 separation

High-Performance Perovskite Quantum Dot Solar Cells Enabled by Incorporation with Dimensionally Engineered Organic Semiconductor

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Nano-Micro Letters 2022年第12期14卷 272-285页

作者： Seyeong Lim Dae Hwan Lee Hyuntae choi Yelim choi Dong Geon Lee sung Beom Cho Seonkyung Ko j.ngmin choi Younghoon Kim Taiho Park Department of Chemical Engineering Pohang University of Science and Technology(POSTECH)Pohang 37673Republic of Korea Department of Materials Science and Engineering Hanyang UniversitySeoul 04763Republic of Korea Center of Materials Digitalization Korea Institute of Ceramic Engineering and Technology(KICET)Jinju 52851Republic of Korea Department of Materials Science and Engineering Ajou UniversitySuwon 16499Republic of Korea Department of Energy Science and Engineering Daegu Gyeongbuk Institute of Science and Technology(DGIST)Daegu 42988Republic of Korea Department of Chemistry Kookmin UniversitySeoul 02707Republic of Korea

Perovskite quantum dots(PQDs)have been considered promising and effective photovoltaic absorber due to their superior optoelectronic properties and inherent material merits combining perovskites and ***,they exhibit low moisture stability at room humidity(20-30%)owing to many surface defect sites generated by inefficient ligand exchange *** surface traps must be re-passivated to improve both charge transport ability and moisture *** address this issue,PQD-organic semiconductor hybrid solar cells with suitable electrical properties and functional groups might dramatically improve the charge extraction and defect *** organic semiconductors are typically low-dimensional(1D and 2D)and prone to excessive self-aggregation,which limits chemical interaction with *** this work,we designed a new 3D star-shaped semiconducting material(Star-TrCN)to enhance the compatibility with *** robust bonding with Star-TrCN and PQDs is demonstrated by theoretical modeling and experimental *** Star-TrCN-PQD hybrid films show improved cubic-phase stability of CsPbI_(3)-PQDs via reduced surface trap states and suppressed moisture *** a result,the resultant devices not only achieve remarkable device stability over 1000 h at 20-30%relative humidity,but also boost power conversion efficiency up to 16.0%via forming a cascade energy band structure.

关键词： CsPbI3 quantum dots Star-shaped organic semiconductors Hybrid perovskite quantum dots Solar cell stability High-efficiency photovoltaics

Application of Integrated Database to the Casting Design

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j.urnal of Materials Science & Technology 2008年第3期24卷 351-355页

作者： In-sung Cho Seung-Mok Yoo Chae-Ho Lim j.ong-Kil choi KITECH 7-47 Songdo-dongYeonsu-gu

Construction of integrated database including casting shapes with their casting design, technical knowledge, and thermophysical properties of the casting alloys were introduced in the present study. Recognition tech- nique for casting design by industrial computer tomography was used for the construction of shape database. Technical knowledge of the casting processes such as ferrous and non-ferrous alloys and their manufacturing process of the castings were accumulated and the search engine for the knowledge was developed. Database of thermophysical properties of the casting alloys were obtained via the experimental study, and the properties were used for the in-house computer simulation of casting process. The databases were linked with intelligent casting expert system developed in center for e-design, KITECH. It is expected that the databases can help non casting experts to devise the casting and its process. Various examples of the application by using the databases were shown in the present study.

关键词： Integrated database Casting design Shape recognition

Particle morphology control for spherical powder fabrication using the ball milling process with DEM simulation

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Particuology 2024年第7期90卷 41-50页

作者： Battsetseg j.rgalsaikhan Khulan Uranchimeg Amgalan Bor Kyung sung Kim Heekyu choi Research Institute of Future Convergence Changwon National UniversityChangwonGyoungnam 641-773Republic of Korea Graduate School of Material Science Engineering Changwon National UniversityChangwonGyoungnam 641-773Republic of Korea Department of Chemical and Biological Engineering School of Engineering and Applied SciencesNational University of MongoliaUlaanbaatar 14200Mongolia Department of Mechatronics Convergence Engineering College of Future ConvergenceChangwon National UniversityChangwonGyoungnam 641-773Republic of Korea Graduate School of Convergence on Culture Technology Changwon National UniversityChangwonGyoungnam 641-773Republic of Korea

Characteristics of spherical particles on copper powder and changing sizes were studied in a ball mill under various experimental conditions,such as different ball diameters,high rotation speeds,and milling times,using a discrete element method(DEM)*** experiment has investigated the characteristics of spherical particle morphology evolution involved in the mechanical alloying of copper *** morphological evolution of the copper particle was analyzed using scanning electron microscopy(SEM).A spherical copper particle was shown with a roundness value using imagej.*** DEM was used to simulate the ball motion in a planetary ball mill,and the impact energy and shear energy generated during the collision were analyzed to estimate the contact number between the ball and the ball ***,as the size of the ball decreased,the number of ball-to-ball and ball-to-wall contacts increased accordingly,and the spherical shape of the copper powder changed.

关键词： Planetary ball mill DEM simulation Spherical particle morphology Copper powder Ball diameter