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9-Hydroxy-6,7-dimethoxydalbergiquinol suppresses hydrogen peroxide-induced senescence in human dermal fibroblasts through induction of sirtuin-1 expression

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Asian Pacific Journal of Tropical Biomedicine 2021年第2期11卷 89-96页

作者： Seok-Hee Lim Bing Si Li Ri Zhe Zhu byung-min choi Department of Biochemistry School of MedicineInstitute of BiotechnologyWonkwang University460 Iksandae-roIksanJeonbuk 54538Republic of Korea

Objective:To investigate the potential anti-aging mechanism of9-hydroxy-6,7-dimethoxydalbergiquinol(HDDQ)on hydrogen peroxide(H2O2)-induced oxidative stress in human dermal fibroblasts(HDFs).Methods:The effect of HDDQ on cell viability was assessed by MTT assay,and the effects of HDDQ on senescence-like phenotypes were determined by senescence-associatedβ-galactosidase(SA-β-gal)staining,Western blotting analysis,and a cell proliferation *** expression level and activity of sirtuin-1(SIRT1)induced by HDDQ were also ***:HDDQ reversed senescence-like phenotypes in the oxidant-challenged model,through reducing SA-β-gal activity and promoting cell ***,decreases in ac-p53,p21Cip1/WAF1,and p16Ink4a and an increase in p Rb were *** induced the expression of SIRT1 in a concentration-and time-dependent ***,HDDQ inhibited H2O2-induced phosphorylation of Akt by SIRT1 up-regulation and reduced SA-β-gal ***:HDDQ inhibits H2O2-induced premature senescence and upregulation of SIRT1 expression plays a vital role in the inhibition of the senescence phenotype in HDFs.

关键词： 9-Hydroxy-6,7-dimethoxydalbergiquinol Hydrogen peroxide Senescence Sirtuin-1 Human dermal fibroblasts

1,2,3,4,6-penta-O-galloyl-β-D-glucose up-regulates heme oxygenase-1 expression by stimulating Nrf2 nuclear translocation in an extracellular signal-regulated kinase-dependent manner in HepG2 cells

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World Journal of Gastroenterology 2006年第2期12卷 214-221页

作者： Hyun-Ock Pae Gi-Su Oh Sun-On Jeong Gil-Saeng Jeong Bok-Soo Lee byung-min choi Ho-Sub Lee Hun-Taeg Chung Medicinal Resources Research Institute Wonkwang UniversityIksan-ShiChunbug570-749Republic of Korea Department of Microbiology and Immunology Wonkwang University School of MedicineWonkwang UniversityIksan-ShiChunbug570-749Republic of Korea

AIM: To examine the potency of 1,2,3,4,6-penta-O-galloyl-β-D-glucose (PGG) as a hepatic heme oxygen-ase-1(HO-1) inducer and its regulation in HepG2 cells. METHODS: Expression of HO-1 and NF-E2-related factor 2 (Nrf2) and activation of mitogen-activated protein (MAP) kinases were analyzed by Western blot, immuno-fluorescence assay, and flow cytometry. Transfections of HO-1 gene, small interfering RNAs for HO-1 and Nrf2, and dominant-negative gene for MAP/extracellular signal-regulated kinase (ERK) were carried out to dissect the signaling pathways leading to HO-1 expression in HepG 2 cells. RESULTS: PGG up-regulated HO-1 expression and this expression conferred cytoprotection against oxidative injury induced by t-butyl hydroperoxide. Moreover, PGG induced Nrf2 nuclear translocation, which was found to be an upstream step of PGG-induced HO-1 expression, and ERK activation, of which pathway was involved in PGG-induced Nrf2 nuclear translocation, HO-1 expression and cytoprotection. CONCLUSION: PGG up-regulates HO-1 expression by stimulating Nrf2 nuclear translocation in an ERK-depen-dent manner, and HO-1 expression by PGG may serve as one of the important mechanisms for its hepatoprotective effects.

关键词： 1,2,3,4,6-penta-O-galloyl-β-D-glucose Heme oxygenase-1 Oxidative stress Hepatoprotection

Wave-Tide-Surge Coupled Simulation for Typhoon Maemi

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China Ocean Engineering 2013年第2期27卷 141-158页

作者： byung Ho choi byung Il min Kyeong Ok Kim Jin Hee Yuk Department of Civil and Environmental Engineering Sungkyunkwan University Marine Environments & Conservation Research Division Korea Institute of Ocean Science & Technology Supercomputing Center Korea Institute of Science and Technology Information

The main task of this study focuses on studying the effect of wave-current interaction on currents, storm surge and wind wave as well as effects of current induced wave refraction and current on waves by using numerical models which consider the bottom boundary layer and sea surface roughness parameter for shallow and smooth bed area around Korean Peninsula. The coupled system （unstructured-mesh SWAN wave and ADCIRC） run on the same unstructured mesh. This identical and homogeneous mesh allows the physics of wave-circulation interactions to be correctly resolved in both models. The unstructured mesh can be applied to a large domain allowing all energy from deep to shallow waters to be seamlessly followed. There is no nesting or overlapping of structured wave meshes, and no interpolation is required. In response to typhoon Maemi （2003）, all model components were validated independently, and shown to provide a faithful representation of the system＇s response to this storm. The waves and storm surge were allowed to develop on the continental shelf and interact with the complex nearshore environment. The resulting modeling system can be used extensively for prediction of the typhoon surge. The result show that it is important to incorporate the wave-current interaction effect into coastal area in the wave-tide-surge coupled model. At the same time, it should consider effects of depth-induced wave breaking, wind field, currents and sea surface elevation in prediction of waves. Specially, we found that：（1） wave radiation stress enhanced the current and surge elevation otherwise wave enhanced nonlinear bottom boundary layer decreased that, （2） wind wave was significantly controlled by sea surface roughness thus we cautiously took the experimental expression. The resulting modeling system can be used for hindcasting （prediction） the wave-tide-surge coupled environments at complex coastline, shallow water and fine sediment area like areas around Korean Peninsula.

关键词： typhoon Maemi finite element model tide-surge-wave coupling

Infrared-harvesting colloidal quantum dot inks for efficient photovoltaics: Impact of surface chemistry and device engineering

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Journal of Materials Science & Technology 2023年第16期147卷 224-240页

作者： Younghoon Kim min-Jae choi Jongmin choi Department of Chemistry Kookmin UniversitySeoul02707Republic of Korea Department of Chemical and Biochemical Engineering Dongguk UniversitySeoul04620Republic of Korea Department of Energy Science and Engineering Daegu Gyeongbuk Institute of Science and Technology(DGIST)Daegu42988Republic of Korea

Colloidal quantum dots(CQDs)are promising semiconducting materials,which can be used as a photoactive layer in various optoelectronic applications,because of their size-tunable bandgap energy,solution processability,and excellent optical and optoelectronic *** particular,these features have generated great interest in the development of CQD solar cells and led to a rapid increase in their power conversion *** improvements were enabled by many innovative approaches in terms of CQD’s surface chemistry and device architecture *** this review,a critical overview of the research progress in CQD solar cells is presented with a focus on the strategies adopted for achieving record efficiency in CQD solar *** strategies include the use of organic/inorganic surface ligands,pre-and post-treatment of CQDs,and solid-state/solution-phase ligand ***,we provide an understanding of the research history to inspire the rational design of next-generation CQD optoelectronic devices,such as solar cells,light-emitting diodes,and *** research on the development of infrared CQD solar cells as complementary platforms to other solar cell technologies is also critically discussed to provide another perspective on CQD technologies.

关键词： Quantum dot Lead sulfide Ligand exchange Colloidal ink Infrared light Solar cell

Subacute electroacupuncture at Baihui (GV 20) and Dazhui (GV 14) promotes post-stroke functional recovery via neurogenesis and astrogliosis in a photothrombotic stroke mouse model

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Journal of Traditional Chinese Medicine 2019年第6期39卷 833-841页

作者： Young-Wook Park Gi Yoon Heo min Jae Kim Seo-Yeon Lee byung Tae choi Hwa Kyoung Shin Division of Meridian and Structural Medicine School of Korean MedicinePusan National UniversityYangsanGyeongnam 50612Republic of Korea Department of Korean Medical Science School of Korean MedicinePusan National UniversityYangsanGyeongnam 50612Republic of Korea Graduate Training Program of Korean Medicine for Healthy-Aging Pusan National UniversityYangsanGyeongnam 50612Republic of Korea Korean Medical Science Research Center for Healthy-Aging Pusan National UniversityYangsanGyeongnam 50612Republic of Korea

OBJECTIVE:To investigate the optimal timing and underlying mechanism of electroacupuncture(EA)at Baihui(GV 20)and Dazhui(GV 14)for improved long-term functional recovery after focal cerebral ischemia in a photothrombotic stroke mouse ***:Totally 50 adult male C57 BL/6 J mice were assigned into 5 groups:(a)the control group,sham-operated mice(n=10);(b)the vehicle group,focal cerebral ischemia induction without EA(n=10);(c)the acute EA group,mice received EA immediately post-ischemia,followed by once-daily treatments for 7 consecutive days(n=10);(d)the subacute EA group,mice received EA 4 days post-ischemia,followed by once-daily treatments for 7 consecutive days(n=10);(e)the delayed EA *** stimulation(2 Hz,2 V for 20 min)was applied to acupuncture points(acupoints),Baihui(GV 20)and Dazhui(GV 14),once a day for 7 consecutive days beginning immediately(acute treatment),4 d(subacute treatment)and 10 d(delayed treatment)after focal cerebral ischemia in C57 BL/6 J *** assessments were conducted 21 and 28 d post-ischemia and histopathological analyses were performed 28 days ***:The subacute EA treatment at Baihui(GV20)and Dazhui(GV 14)significantly improved functional recovery compared to the vehicle group 28 d after ischemic brain injury,although brain atrophy was not *** number of Neu N+and Neu N+/Brd U+cells as well as GFAP intensity in the ipsilateral cortex were significantly increased in the subacute group compared to the vehicle group 28 d *** concluded that EA stimulation 4 d post-ischemia(subacute treatment)enhanced neurogenesis and astrogliosis,likely contributing to long-term functional recovery following focal cerebral ***:Our findings suggest that the timing of the EA therapy at Baihui(GV 20)and Dazhui(GV 14)determines the therapeutic effects in mice with focal cerebral ischemia induced by photothrombotic occlusion.

关键词： Electroacupuncture Stroke Astrocytes Neurogenesis Post-stroke remodeling

Parallel Cloth Simulation Using OpenGL Shading Language

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Computer Systems Science & Engineering 2022年第5期41卷 427-443页

作者： Hongly Va min-Hyung choi min Hong Department of Software Convergence Soonchunhyang UniversityAsan31538Korea Department of Computer Science and Engineering University of Colorado DenverDenverCO 80217USA Department of Computer Software Engineering Soonchunhyang UniversityAsan31538Korea

The primary goal of cloth simulation is to express object behavior in a realistic manner and achieve real-time performance by following the fundamental concept of *** general,the mass–spring system is applied to real-time cloth simulation with three types of ***,hard spring cloth simulation using the mass–spring system requires a small integration time-step in order to use a large stiffness ***,to obtain stable behavior,constraint enforcement is used instead of maintenance of the force of each *** force computation involves a large sparse linear solving *** to the large computation,we implement a cloth simulation using adaptive constraint activation and deactivation techniques that involve the mass-spring system and constraint enforcement method to prevent excessive elongation of *** the same time,when the length of the spring is stretched or compressed over a defined threshold,adaptive constraint activation and deactivation method deactivates the spring and generate the implicit *** method that uses a serial process of the Central Processing Unit(CPU)to solve the system in every frame cannot handle the complex structure of cloth model in *** simulation utilizes the Graphic Processing Unit(GPU)parallel processing with compute shader in OpenGL Shading Language(GLSL)to solve the system *** this paper,we design and implement parallel method for cloth simulation,and experiment on the performance and behavior comparison of the mass-spring system,constraint enforcement,and adaptive constraint activation and deactivation techniques the using GPU-based parallel method.

关键词： Adaptive constraint cloth simulation constraint enforcement GLSL compute shader mass–spring system parallel GPU

Real-time Volume Preserving Constraints for Volumetric Model on GPU

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Computers, Materials & Continua 2022年第10期73卷 831-848页

作者： Hongly Va min-Hyung choi min Hong Department of Software Convergence Soonchunhyang UniversityAsan31538Korea Department of Computer Science and Engineering University of Colorado DenverDenver80217COUSA Department of Computer Software Engineering Soonchunhyang UniversityAsan31538Korea

This paper presents a parallel method for simulating real-time 3D deformable objects using the volume preservation mass-spring system method on tetrahedron *** general,the conventional mass-spring system is manipulated as a force-driven method because it is fast,simple to implement,and the parameters can be ***,the springs in traditional mass-spring system can be excessively elongated which cause severe stability and robustness issues that lead to shape restoring,simulation blow-up,and huge volume loss of the deformable *** addition,traditional method that uses a serial process of the central processing unit(CPU)to solve the system in every frame cannot handle the complex structure of deformable object in ***,the first order implicit constraint enforcement for a mass-spring model is utilized to achieve accurate visual realism of deformable objects with tough constraint *** this paper,we applied the distance constraint and volume conservation constraints for each tetrahedron element to improve the stability of deformable object simulation using the mass-spring system and behave the same as its real-world *** reduce the computational complexity while ensuring stable simulation,we applied a method that utilizes OpenGL compute shader,a part of OpenGL Shading Language(GLSL)that executes on the graphic processing unit(GPU)to solve the numerical problems *** applied the proposed methods to experimental volumetric models,and volume percentages of all objects are *** average volume percentages of all models during the simulation using the mass-spring system,distance constraint,and the volume constraint method were 68.21%,89.64%,and 98.70%,*** proposed approaches are successfully applied to improve the stability of mass-spring system and the performance comparison from our experimental tests also shows that the GPU-based method is faster than CPU-based implementation for all cases.

关键词： Deformable object simulation mass-spring system implicit constraint enforcement volume conservation constraint GPU parallel computing

Moth-eye Structured Polydimethylsiloxane Films for High-Efficiency Perovskite Solar Cells

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Nano-Micro Letters 2019年第3期11卷 271-280页

作者： mincheol Kim Segeun Jang Jiwoo choi Seong min Kang Mansoo choi Global Frontier Center for Multiscale Energy Systems Seoul National UniversitySeoul151.744Republic of Korea Department of Mechanical and Aerospace Engineering Seoul National UniversitySeoul151.744Republic of Korea Department of Mechanical Engineering Hanbat National UniversityDaejeon34158Republic of Korea Department of Mechanical Engineering Chungnam National UniversityDaejeon34134Republic of Korea

Large-area polydimethylsiloxane(PDMS)films with variably sized moth-eye structures were fabricated to improve the efficiency of perovskite solar *** approach that incorporated photolithography,bilayer PDMS deposition and replication was used in the fabrication *** simply attaching the moth-eye PDMS films to the transparent substrates of perovskite solar cells,the optical properties of the devices could be tuned by changing the size of the moth-eye *** device with 300-nm moth-eye PDMS films greatly enhanced power conversion efficiency of ~21 % due to the antireflective effect of the moth-eye ***,beautiful coloration was observed on the 1000-nm moth-eye PDMS films through optical interference caused by the diffraction grating *** results imply that moth-eye PDMS films can greatly enhance the efficiency of perovskite solar cells and building-integrated photovoltaics.

关键词： Polydimethylsiloxane films Moth-eye Photolithography Perovskite solar cells Photovoltaic

Formulation of a film-coated dutasteride tablet bioequivalent to a soft gelatin capsule(Avodart~?): Effect of γ-cyclodextrin and solubilizers

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Asian Journal of Pharmaceutical Sciences 2019年第3期14卷 313-320页

作者： Mi-Hong min Jin-Hyong Park Mi-Ran choi Jong-Hyun Hur byung-Nak Ahn Dae-Duk Kim College of Pharmacy and Research Institute of Pharmaceutical Sciences Seoul National UniversitySeoul08826Republic of Korea Central Research Institute Whanin Pharmaceutical Company4FGBSA107Gwanggyo-roYeongtong-guSuwon16229Republic of Korea

The aim of this study was to optimize a tablet formulation of dutasteride that is bioequivalent to a commercially available soft gelatin capsule(Avodart~?). The effect of cyclodextrin on enhancing the aqueous solubility of dutasteride was investigated, after which the formulation was further optimized with solubilizing polymer and surfactant. Among the cyclodextrins tested, the highest solubility was observed when dutasteride was complexed with γ-cyclodextrin. Moreover, the addition of polyvinylpyrrolidone and Gelucire/TPGS further enhanced the solubility of dutasteride. Differential scanning calorimetry(DSC) and powder X-ray diffraction(pX RD) studies demonstrated that dutasteride existed in the amorphous form in the complex. Optimized dutasteride complexes were selected after a pharmacokinetic study in rats, and film-coated tablets were prepared by the direct compression method. In vitro dissolution profiles for the tablets of dutasteride complexes were similar to those of the reference. Moreover, pharmacokinetic parameters including the C max and AUC values after oral administration in beagle dogs were not significantly different from those of the reference with a relative bioavailability of 92.4%. These results suggest the feasibility of developing a tablet formulation of dutasteride using cyclodextrin complex in addition to a solubilizing polymer and surfactant.

关键词： Dutasteride Tablet Cyclodextrin Complex Formulation