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Journal of Traditional Chinese Medicine 2013年第5期33卷 658-663页

作者： eunjeong choi Gunhee Kim Plant Resources Research Institute Duksung Women's University

OBJECTIVE:To investigate the mechanism underlying the anticancer effect of Artemisia species through the inhibition of cell growth and induction of apoptosis in breast carcinoma ***:To evaluate the anticancer activity of methanol extracts of eight Artemisia species(Artemisia stolonifera,Artemisia selengensis,Artemisia japonica,Artemisia Montana,Artemisia capillaris,Artemisia sylvatica,Artemisia keiskeana,and Artemisia scoparia),we first investigated the proliferation of estrogen receptor(ER)-positive MCF-7breast carcinoma cells exposed to 5 or 200 g/mL for72 *** induction was assessed by an Annexin V binding assay in cells exposed to extracts at a high concentration(200 g/mL).To verify the mechanism of apoptosis,ER expression and its related signaling was investigated using an immunoblot assay under the same ***:MCF-7 cells showed the strongest antiproliferative response to the tested ***-er,a biphasic effect was observed:the extracts inhibited proliferation at high concentrations whereas they stimulated it at low *** expression was similarly modulated by the ***,all of the extracts induced apoptosis at a high concentration(200 g/mL).Compared to the control level,exposure to the extracts resulted in a remarkable increase in the shift of cell ***:The present study suggests that the tested Artemisia species exerted their anticancer effects through the induction of apoptosis via an ER-related pathway.

关键词： Artemisia Breast neoplasms Bcl-2gene Cyclin D1 Estrogen receptor

Anticancer,antiobesity,and anti-inflammatory activity of Artemisia species invitro

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Journal of Traditional Chinese Medicine 2013年第1期33卷 92-97页

作者： eunjeong choi Heesook Park Jehyuk Lee Gunhee Kim Plant Resources Research Institute Duksung Women's University

OBJECTIVE： To investigate the anticancer, antiin flammatory, and antiobesity activity of methanol extracts of eight distinct species： Artemisia Stolon ifera （AST）, Artemisia Selengensis （ASE）, Artemisia .la ponica, Artemisia Montana, Artemisia Capillaris （ACA）, Artemisia Sylvatica （ASY）, Artemisio Keiskeana （AKE）, and Artemisia Scoparia （ASC） in vitro. METHODS： Antiproliferative activity was investigat ed in human breast cancer estrogen receptora pos itive T47D and negative HS578T cell lines exposed to the extracts at various concentrations （5200 mgl mL）for24, 48, and 72 h. For evaluating the antiin flammatory activity of the extracts, inhibition of ni trite synthesis was investigated in lipopolysaccha ride （LPS）stimulated cultures of macrophages cells exposed to 10, 50, 100, and 200 mglmL for 24 h. The antiobesity activity of the extracts was deter mined as triglyceride content and by a lipolysis as say in differentiated 3T3LI cells exposed to the extracts for 72 h at the same concentrations de scribed above. RESULTS： All extracts showed similar antiprolifera tive activity in a dose and timedependent man ner in HS578T cells. Although extracts at lower con centrations and shorter times stimulated growth of T47D cells, the antiproliferative effects of the extracts on T47D cells at higher concentrations （〉100 mg/ mL） for 72 h were significantly greater than those of HS578T cells. In case of antiinflammatory activi ty, some extracts （AST, ASE, ACA, and AKE） signifi cantly reduced nitric oxide production at higher concentrations in the presence of LPS compared with that in control cells. Antiobesity activity was showed with reducing lipid accumulation signifi cantly （〉50%） at concentrations above 100 mg/mL in most extracts （except AST and ACA）. Additional ly, AKE and ASC increased lipolysis by 11%24% compared with that in the control. CONCLUSION： Artemisia spp. demonstrates poten tial as bioactive food supplements.

关键词： Artemisia Anticancer Anti-inflammatory Antiobesity In vitro

3D-printed gelatin methacrylate (GelMA)/ silanated silica scaffold assisted by two-stage cooling system for hard tissue regeneration

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Regenerative Biomaterials 2021年第2期8卷 50-63页

作者： eunjeong choi Dongyun Kim Donggu Kang Gi Hoon Yang Bongsu Jung MyungGu Yeo Min-Jeong Park SangHyun An KyoungHo Lee Jun Sik Kim Jong Chul Kim Woonhyeok Jeong Hye Hyun Yoo Hojun Jeon Research Institute of Additive Manufacturing and Regenerative Medicine Baobab Healthcare Inc55 Hanyangdaehak-RoAnsanGyeonggi-do 15588South Korea Department of Mechanical Engineering Korea Polytechnic UniversitySangidaehak-roSiheungGyeonggi-do 15073South Korea Medical Device Development Center Daegu-Gyeongbuk Medical Innovation Foundation(DGMIF)80Cheombok-roDong-guDaegu 41061South Korea Laboratory Animal Center Daegu-Gyeongbuk Medical Innovation Foundation(DGMIF)80 Cheombok-roDong-guDaegu 41061South Korea Department of Plastic and Reconstructive Surgery Dongsan Medical CenterKeimyung University College of Medicine1035 Dalgubeol-daeroDalseo-guDaegu 42601South Korea Institute of Pharmaceutical Science and Technology College of PharmacyHanyang University55 Hanyangdaehak-RoAnsanGyeonggi-Do 15588South Korea

Among many biomaterials,gelatin methacrylate(GelMA),a photocurable protein,has been widely used in 3D bioprinting process owing to its excellent cellular responses,biocompatibility and ***,GelMA still shows a low processability due to the severe temperature dependence of *** overcome this obstacle,we propose a two-stage temperature control system to effectively control the viscosity of *** optimize the process conditions,we evaluated the temperature of the cooling system(jacket and stage).Using the established system,three GelMA scaffolds were fabricated in which different concentrations(0,3 and 10 wt%)of silanated silica particles were *** evaluate the performances of the prepared scaffolds suitable for hard tissue regeneration,we analyzed the physical(viscoelasticity,surface roughness,compressive modulus and wettability)and biological(human mesenchymal stem cells growth,western blotting and osteogenic differentiation)***,the composite scaffold with greater silica contents(10 wt%)showed enhanced physical and biological performances including mechanical strength,cell initial attachment,cell proliferation and osteogenic differentiation compared with those of the *** results indicate that the GelMA/silanated silica composite scaffold can be potentially used for hard tissue regeneration.

关键词： 3D bioprinting gelatin methacrylate silanated silica cooling system human mesenchymal stem cells

Development of vehicle-recognition method on water surfaces using LiDAR data:SPD^(2)(spherically stratified point projection with diameter and distance)

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Defence Technology（防务技术） 2024年第6期36卷 95-104页

作者： Eon-ho Lee Hyeon Jun Jeon Jinwoo choi Hyun-Taek choi Sejin Lee The Department of Mechanical Engineering Kongju National University1223-24 Cheonan-daeroCheonan 31080Republic of Korea Ocean System Engineering Research Division Korea Research Institute of Ships and Ocean Engineering(KRISO)Daejeon 34103Republic of Korea The Division of Mechanical&Automotive Engineering Kongju National University1223-24 Cheonan-daeroCheonan 31080Republic of Korea

Swarm robot systems are an important application of autonomous unmanned surface vehicles on water *** monitoring natural environments and conducting security activities within a certain range using a surface vehicle,the swarm robot system is more efficient than the operation of a single object as the former can reduce cost and save *** is necessary to detect adjacent surface obstacles robustly to operate a cluster of unmanned surface *** this purpose,a LiDAR(light detection and ranging)sensor is used as it can simultaneously obtain 3D information for all directions,relatively robustly and accurately,irrespective of the surrounding environmental *** the GPS(global-positioning-system)error range exists,obtaining measurements of the surface-vessel position can still ensure stability during platoon *** this study,a three-layer convolutional neural network is applied to classify types of surface *** aim of this approach is to redefine the sparse 3D point cloud data as 2D image data with a connotative meaning and subsequently utilize this transformed data for object classification ***,we have proposed a descriptor that converts the 3D point cloud data into 2D image *** use this descriptor effectively,it is necessary to perform a clustering operation that separates the point clouds for each *** developed voxel-based clustering for the point cloud ***,using the descriptor,3D point cloud data can be converted into a 2D feature image,and the converted 2D image is provided as an input value to the *** intend to verify the validity of the proposed 3D point cloud feature descriptor by using experimental data in the ***,we explore the feasibility of real-time object classification within this framework.

关键词： Object classification Clustering 3D point cloud data LiDAR(light detection and ranging) Surface vehicle

Synthetic brochosomes:Design,synthesis,and applications

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Nano Research 2024年第2期17卷 734-742页

作者： Lin Wang Jinsol choi Tak-Sing Wong Department of Mechanical Engineering The Pennsylvania State UniversityUniversity ParkPA 16802USA Materials Research Institute The Pennsylvania State UniversityUniversity ParkPA 16802USA Department of Biomedical Engineering The Pennsylvania State UniversityUniversity ParkPA 16802USA

Brochosomes,which are nanoscopic buckyball-shaped granules produced by leafhoppers,are one of the most intricate structures discovered in *** functions of brochosomes have been proposed but only a few have been experimentally validated due to the challenge of fabricating their synthetic *** in micro-and nanofabrication have recently led to the emergence of synthetic brochosomes,opening up new possibilities for innovative *** review explores the early discovery of natural brochosomes and their geometrical features,followed by the recent progress in fabricating synthetic brochosomes and their *** on future applications and challenges in the scalable manufacturing of synthetic brochosomes are discussed.

关键词： synthetic brochosomes leafhopper antireflection superhydrophobicity surface-enhanced Raman scattering photocatalyst energy harvesting

Correlation between hydration properties and electrochemical performances on Ln cation size effect in layered perovskite for protonic ceramic fuel cells

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Journal of Energy Chemistry 2024年第1期88卷 1-9,I0001页

作者： Inhyeok Cho Jiwon Yun Boseok Seong Junseok Kim Sun Hee choi Ho-Il Ji Sihyuk choi Department of Mechanical Engineering Kumoh National Institute of TechnologyGumi 39177GyeongbukRepublic of Korea Department of Aeronautics Mechanical and Electronic Convergence EngineeringKumoh National Institute of TechnologyGumi 39177GyeongbukRepublic of Korea Center for Energy Materials Research Korea Institute of Science and Technology(KIST)Seoul 02792Republic of Korea Center for Hydrogen and Fuel Cell Research Clean Technology Research DivisionKorea Institute of Science and Technology(KIST)Seoul 02792Republic of Korea Department of Energy and Environmental Engineering University of Science and TechnologySeoul 02792Republic of Korea Nanomaterials Science and Engineering Korea University of Science and Technology(UST)KIST CampusSeoul 02792Republic of Korea

PrBa_(0.5)Sr_(0.5)Co_(1.5)Fe_(0.5)O_(5+δ)(PrBSCF) has attracted much research interest as a potential triple ionic and electronic conductor(TIEC) electrode for protonic ceramic fuel cells(PCFCs). The chemical formula for Pr BSCF is AA'B_(2)O_(5+δ), with Pr(A-site) and Ba/Sr(A'-site) alternately stacked along the c-axis. Due to these structural features, the bulk oxygen ion diffusivity is significantly enhanced through the disorder-free channels in the PrO layer;thus, the A site cations(lanthanide ions) play a pivotal role in determining the overall electrochemical properties of layered perovskites. Consequently, previous research has predominantly focused on the electrical properties and oxygen bulk/surface kinetics of Ln cation effects,whereas the hydration properties for PCFC systems remain unidentified. Here, we thoroughly examined the proton uptake behavior and thermodynamic parameters for the hydration reaction to conclusively determine the changes in the electrochemical performances depending on LnBa_(0.5)Sr_(0.5)Co_(1.5)Fe_(0.5)O_(5+δ)(LnBSCF,Ln=Pr, Nd, and Gd) cathodes. At 500 ℃, the quantitative proton concentration of PrBSCF was 2.04 mol% and progressively decreased as the Ln cation size decreased. Similarly, the Gibbs free energy indicated that less energy was required for the formation of protonic defects in the order of Pr BSCF < Nd BSCF < Gd BSCF. To elucidate the close relationship between hydration properties and electrochemical performances in LnBSCF cathodes, PCFC single cell measurements and analysis of the distribution of relaxation time were further investigated.

关键词： Protonic ceramic fuel cell Cathode Triple ionic and electronic conductor Hydration property Proton uptake Gibbs free energy

Learning feature alignment and dual correlation for few‐shot image classification

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CAAI Transactions on Intelligence Technology 2024年第2期9卷 303-318页

作者： Xilang Huang Seon Han choi Department of Electronic and Electrical Engineering Ewha Womans UniversitySeoulSouth Korea Graduate Program in Smart Factory Ewha Womans UniversitySeoulSouth Korea

Few‐shot image classification is the task of classifying novel classes using extremely limited labelled *** perform classification using the limited samples,one solution is to learn the feature alignment(FA)information between the labelled and unlabelled sample *** FA methods use the feature mean as the class prototype and calculate the correlation between prototype and unlabelled features to learn an alignment ***,mean prototypes tend to degenerate informative features because spatial features at the same position may not be equally important for the final classification,leading to inaccurate correlation ***,the authors propose an effective intraclass FA strategy that aggregates semantically similar spatial features from an adaptive reference prototype in low‐dimensional feature space to obtain an informative prototype feature map for precise correlation ***,a dual correlation module to learn the hard and soft correlations was developed by the *** module combines the correlation information between the prototype and unlabelled features in both the original and learnable feature spaces,aiming to produce a comprehensive cross‐correlation between the prototypes and unlabelled *** both FA and cross‐attention modules,our model can maintain informative class features and capture important shared features for *** results on three few‐shot classification benchmarks show that the proposed method outperformed related methods and resulted in a 3%performance boost in the 1‐shot setting by inserting the proposed module into the related methods.

关键词： image classification machine learning metric learning

Rapid monitoring of indoor airborne influenza and coronavirus with high air flowrate electrostatic sampling and PCR analysis

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Frontiers of Environmental Science & Engineering 2024年第7期18卷 73-85页

作者： Sanggwon An Sangsoo choi Hyeong Rae Kim Jungho Hwang School of Mechanical Engineering Yonsei UniversitySeoul 02876Republic of Korea Gas Metrology Group Korea Research Institute of Standards and Science(KRISS)Daejeon 34113Republic of Korea

The World Health Organization has raised concerns about the possibility of airborne transmission in enclosed and poorly ventilated ***,rapid monitoring of airborne viruses is necessary in multi-use facilities with dense ***,an electrostatic air sampler(250 L/min)was developed in this work to obtain indoor viral aerosol samples for analysis via the Polymerase Chain Reaction(PCR).Aerosol tests with H1N1 and HCoV-229E were performed to evaluate the sample collection *** analysis,along with another aerosol test,was conducted to evaluate the recovery of the virus particles collected by the *** laboratory tests,our electrostatic sampler obtained viral samples that were detectable by PCR under the simulated viral pandemic scenario(3000 RNA copies per cubic meter of air)within 40 *** resulting cycle threshold(C)values were 35.07 and 37.1 for H1N1 and HCoV-229E,*** the performance evaluation in the laboratory,field tests were conducted in a university classroom from October 28 to December 2,*** A and HCoV-229E were detected in two air samples,and the corresponding C,values were 35.3 and *** PCR results are similar to those obtained from laboratory tests,considering the simulatedviralpandemic scenario.

关键词： Airborne virus Electrostatic sampler Rapid monitoring Indoor environment Field test

Enhancing BiVO_(4)photoanode performance by insertion of an epitaxial BiFeO_(3)ferroelectric layer

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Journal of Energy Chemistry 2024年第2期89卷 71-78,I0003页

作者： Haejin Jang Yejoon Kim Hojoong choi Jiwoong Yang Yoonsung Jung Sungkyun choi Donghyeon Lee Ho Won Jang Sanghan Lee School of Materials Science and Engineering Gwangju Institute of Science and TechnologyGwangju 61005Republic of Korea Department of Materials Science and Engineering Seoul National UniversitySeoul 08826Republic of Korea

BiVO_(4)(BVO)is a promising material as the photoanode for use in photoelectrochemical ***,the high charge recombination and slow charge transfer of the BVO have been obstacles to achieving satisfactory photoelectrochemical *** address this,various modifications have been attempted,including the use of ferroelectric *** materials can form a permanent polarization within the layer,enhancing the separation and transport of photo-excited electron-hole *** this study,we propose a novel approach by depositing an epitaxial BiFeO_(3)(BFO)thin film underneath the BVO thin film(BVO/BFO)to harness the ferroelectric property of *** self-polarization of the inserted BFO thin film simultaneously functions as a buffer layer to enhance charge transport and a hole-blocking layer to reduce charge *** a result,the BVO/BFO photoanodes showed more than 3.5 times higher photocurrent density(0.65 mA cm^(-2))at 1.23 V_(RHE)under the illumination compared to the bare BVO photoanodes(0.18 m A cm^(-2)),which is consistent with the increase of the applied bias photon-to-current conversion efficiencies(ABPE)and the result of electrochemical impedance spectroscopy(EIS)*** results can be attributed to the self-polarization exhibited by the inserted BFO thin film,which promoted the charge separation and transfer efficiency of the BVO photoanodes.

关键词： Photoelectrochemical Photoanode BiVO_(4) Ferroelectric materials BiFeO_(3)

Modeling asymmetric fracture mechanics of Mg alloy wire in drawing process

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Journal of Magnesium and Alloys 2024年第5期12卷 2057-2069页

作者： Sunghoon choi Jongwon Shin Joung Sik Suh Dongchoul Kim Department of Mechanical Engineering Sogang UniversitySeoul04107Republic of Korea Advanced Metals Division Korea Institute of Materials ScienceChangwon 51508Republic of Korea

In this study,a numerical analysis was conducted on the ductile fracture of a 2-mm diameter Mg-1Zn-0.5Mn-0.5Sr-0.1Ca alloy wire during *** hexagonally close-packed crystal structure of Mg alloys causes asymmetric fracture behavior,especially in the compression *** aim of this study is to develop a comprehensive damage model for Mg alloy wire that accurately predicts ductile fracture,with a focus on the compression region.A novel experimental method was introduced to measure the ductile fracture of Mg alloy wires under different stress *** wire drawing process was simulated using the Generalized Incremental Stress-State dependent damage(GISSMO)Model and the Semi-Analytical Model for Polymers(SAMP)*** damage model's prediction and the experimental results were found to be in excellent agreement,especially in determining crack *** analysis established a safe zone diagram for die angle and reduction ratio,and experimental validation confirmed the feasibility of this *** proposed damage model can provide a practical and reliable analysis for optimizing the drawing process of Mg alloy wire.

关键词： Mg alloy Wire drawing Finite element method Damage model Safe zone diagram