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Journal of Magnesium and Alloys 2022年第6期10卷 1672-1679页

作者： joo-hee kang Jiwon Park Kyung Song Chang-Seok Oh Oleg Shchyglo Ingo Steinbach Korea Institute of Materials Science Changwon 51508Republic of Korea Interdisciplinary Centre for Advanced Materials Simulation Ruhr-University Bochum44801 BochumGermany

In this study the partially divorced eutectic microstructure ofα-Mg andβ-Mg17Al12was investigated by electron backscatter diffraction,transmission electron microscopy,and phase-field modeling in hypoeutectic Mg-Al *** orientation relationships between the individual eutecticαgrains,eutecticβphase,and primaryαgrains were *** the amount of eutectic morphology is primarily determined by the Al content,the in-depth microstructure analyses and the phase-field simulation suggest non-interactive nucleation and growth of eutecticαphase in theβphase grown on the interdendritic primaryα***,phase-field simulations showed a preferred nucleation sequence where theβphase nucleates first and subsequently triggers the nucleation of eutecticαphase at the movingβphase solidification front,which supports the microstructural analysis results.

关键词： Mg-Al alloy Partially divorced eutectic Solidification Electron backscatter diffraction Phase-Field modeling

Bimodal grain structures and tensile properties of a biomedical Co-20Cr-15W-10Ni alloy with different pre-strains

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Rare Metals 2021年第1期40卷 20-30页

作者： Cheng-Lin Li Seong-Woo Choi Jeong Mok Oh Jae-Keun Hong Jong-Taek Yeom joo-hee kang Qing-Song Mei Chan hee Park Department of Materials Engineering School of Power and Mechanical EngineeringWuhan UniversityWuhan 430072China Advanced Metals Division.Korea Institute of Materials Science Changwon 51508Republic of Korea Materials Testing&Reliability Division Korea Institute of Materials ScienceChangwon 51508Republic of Korea

The influence of pre-strain on the formation of bimodal grain structures and tensile properties of a Co-20 Cr-15 W-10 Ni alloy was *** bimodal grain structures consist of fine grains(FGs;2-3μm in diameter)and coarse grains(CGs;8-16μm in diameter),which can be manipulated by changing the pre-strain(ε=0.3-0.7)and annealing temperatures(1000-1100℃).High pre-strain applied in the samples can intensify the plasticity heterogeneity through increasing the total dislocation density and the local volumes of high-density *** can essentially result in finer FGs,a higher FG volume fraction,and overall grain refinement in the samples after ***-temperature essentially increases both the size and volume fraction of CGs,leading to an increase in the average grain *** tensile test suggests that the bimodal grain structured samples exhibited both high strength and ductility,yield strengths of621-877 MPa and ultimate tensile strengths of1187-1367 MPa with uniform elongations of 55.0%-71.4%.The superior strength-ductility combination of the samples arises from the specific deformation mechanisms of the bimodal grain *** tensile properties strongly depend on the size ratio and volume fraction of FGs/CGs in addition to the average grain size in the bimodal grain *** grain structures can be modified via changing the pre-strain and annealing temperature.

关键词： Biomaterials Bimodal grain structure Deformation heterogeneity Pinning High strength/ductility

Impact of nonalcoholic fatty liver disease on the risk of gallbladder polyps in lean and non-obese individuals:A cohort study

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Hepatobiliary & Pancreatic Diseases International 2024年第6期23卷 573-578页

作者： Nam hee Kim Ji Hun kang Hong joo Kim Division of Gastroenterology Department of Internal MedicineKangbuk Samsung HospitalSungkyunkwan University School of MedicineSeoulKorea Department of Radiology Hanyang University Guri HospitalHanyang University College of MedicineGuriKorea

Background:The association between non-obese or lean nonalcoholic fatty liver disease(NAFLD)and gallbladder polyps(GBPs)has not yet been *** aimed to determine whether NAFLD is an independent risk factor for the development of GBPs,even in non-obese and lean ***:We analyzed a cohort of 331208 asymptomatic adults who underwent abdominal ultrasonography(US).The risk of GBP development was evaluated according to the obesity and NAFLD ***:The overall prevalence of NAFLD and GBPs≥5 mm was 28.5%and 2.9%,*** prevalence of NAFLD among 160276 lean,77676 overweight and 93256 obese participants was 8.2%,31.2%,and 61.1%,*** with NAFLD had a significantly higher incidence of GBPs with a size of≥5 mm[adjusted odds ratio(OR)=1.18;95%confidence interval(CI):1.11–1.25].A higher body mass index and its categories were also significantly associated with an increased risk of GBPs≥5 ***,risk of GBPs≥5 mm was significantly increased even in NAFLD individuals who are not obese(lean:adjusted OR=1.36,95%CI:1.19-1.54;overweight:adjusted OR=1.14,95%CI:1.03–1.26,respectively).Conclusions:Non-obese/lean NAFLD is an independent risk factor for GBP development,suggesting that NAFLD may play an important role in the pathogenesis of GBPs regardless of the obesity ***,a more thorough evaluation for GBPs may be necessary when hepatic steatosis is detected on abdominal US,even in non-obese or lean individuals.

关键词： Nonalcoholic fatty liver disease Non-obese Lean Gallbladder polyps

Preoperative risk factors for early recurrence in patients with resectable pancreatic ductal adenocarcinoma after curative intent surgical resection

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Hepatobiliary & Pancreatic Diseases International 2018年第5期17卷 450-455页

作者： Nam hee Kim Hong joo Kim Division of Gastroenterology Department of Internal Medicine Kangbuk Samsung Hospital Sungkyunkwan University School of Medicine

Background: Postoperative early recurrence(ER) in patients with pancreatic ductal adenocarcinoma(PDAC) is frequently encountered after curative intent surgery. Nonetheless, clinical significance and risk factors of ER after surgery for PDAC have not been extensively investigated. The aim of this study was to determine preoperative risk predictors for ER in patients with PDAC after upfront surgery. Methods: Eighty-one consecutive patients with PDAC who underwent curative intent surgical resection at kangbuk Samsung Hospital between January 2004 and May 2015 were enrolled. ER was defined as tumor relapse within 6 months after surgery. Results: ER occurred in 26 patients(32.1%), whereas 49 patients(60.5%) had late recurrence( ≥ 6 months after surgery), and 6 patients had no recurrence(7.4%). Univariate analysis showed that C-reactive protein(CRP) > 3.0 mg/dL, modified Glasgow prognostic score(mGPS) = 2, decrease of total lymphocyte count by > 50% of baseline value in the preoperative period, prognostic nutritional index(PNI) 3.0 mg/dL, decrease of total lymphocyte count by > 50% of baseline value, and preoperative SUVmax were significant and independent contributors of ER in patients with resectable PDAC who underwent curative intent surgery. Conclusions: Postoperative ER for resectable PDAC was frequent with poor prognosis after curative intent upfront surgery. It is reasonable to suggest that there is a subgroup of resectable PDAC patients at highrisk of ER and neoadjuvant therapy should be considered in these patients in a clinical trial setting.

关键词： Early recurrence Pancreatic ductal adenocarcinoma Preoperative risk factors C-reactive protein Maximum standardized uptake value

Evaluation of accuracy of linear regression models in predicting urban stormwater discharge characteristics

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Journal of Environmental Sciences 2014年第6期26卷 1313-1320页

作者： Krish J.Madarang joo-Hyon kang Department of Civil and Environmental Engineering Dongguk University-SeoulSeoul 100-715 Korea

Stormwater runoff has been identified as a source of pollution for the environment, especially for receiving waters. In order to quantify and manage the impacts of stormwater runoff on the environment, predictive models and mathematical models have been developed. Predictive tools such as regression models have been widely used to predict stormwater discharge characteristics. Storm event characteristics, such as antecedent dry days （ADD）, have been related to response variables, such as pollutant loads and concentrations. However it has been a controversial issue among many studies to consider ADD as an important variable in predicting stormwater discharge characteristics. In this study, we examined the accuracy of general linear regression models in predicting discharge characteristics of roadway runoff. A total of 17 storm events were monitored in two highway segments, located in Gwangju, Korea. Data from the monitoring were used to calibrate United States Environmental Protection Agency＇s Storm Water Management Model （SWMM）. The calibrated SWMM was simulated for 55 storm events, and the results of total suspended solid （TSS） discharge loads and event mean concentrations （EMC） were extracted. From these data, linear regression models were developed. R2 and p-values of the regression of ADD for both TSS loads and EMCs were investigated. Results showed that pollutant loads were better predicted than pollutant EMC in the multiple regression models. Regression may not provide the true effect of site-specific characteristics, due to uncertainty in the data.

关键词： storrnwater urban runoff linear regression model storm water management model total suspendid solids

Selective apoptotic effect of Zelkova serrata twig extract on mouth epidermoid carcinoma through p53 activation

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International Journal of Oral Science 2012年第2期4卷 78-84页

作者： Hoe-Jin kang Young-joo Jang Laboratory of Cell Cycle and Signal Transduction World Class University Research Department of Nanobiomedical Science and Institute of Tissue Regeneration EngineeringDankook UniversityCheonanKorea

Apoptosis or programmed cell death plays an essential role in chemotherapy-induced tumor cell killing, and inducers of apoptosis are commonly used in cancer therapy. Treatment with Zelkova serrata extracts was performed in human gingival fibroblast （HGF）, mouth epidermoid carcinoma cell （KB）, lower gingival squamous cancer cell （YD38） and tongue mucoepidermoid carcinoma cells （YD15）. We observed that extract prepared from Zelkova serrata twig selectively inhibited proliferation of various oral cancer cells, but not normal gingival fibroblasts, in a dose-dependent manner. Caspase-8-mediated apoptosis was induced by treatment with the extract only in mouth epidermoid carcinoma and not in other types of cancer cells, including lower gingival squamous cell carcinoma. The selective apoptotic effect of Zelkova serrata twig extract in mouth epidermoid carcinoma was dependent on normal p53 status. Apoptosis was not remarkably induced by treatment with the extract in either lower gingival squamous or tongue mucoepidermoid carcinoma cells, both of which contain abnormalities of p53. Upon treatment with Zelkova serrata twig extract, mouth epidermoid carcinoma cells accumulated in S phase by activation of p21. These data indicate that Zelkova serrata twig extract exerted a cancer type-specific, p53-dependent apoptotic effect and disturbed the cell cycle, which suggests that herbal medicine could be a treatment for specific types of cancers.

关键词： anticancer apoptosis oral carcinomas p53 Zelkova serrata

Facile synthesis of graphitic carbon-nitride supported antimony-doped tin oxide nanocomposite and its application for the adsorption of volatile organic compounds

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Journal of Environmental Sciences 2019年第5期31卷 35-42页

作者： Devi Prashad Ojha Jun hee Song Han joo Kim Department of Convergence Technology Engineering Chonbuk National University Eco-friendly Machine Parts Design Center Chonbuk National University

Antimony-doped tin oxide(ATO) nanoparticles with an average size of ～ 6 nm were prepared by co-precipitation and subsequent heat treatment. Graphitic carbon nitride(g-CN)/ATO hybrid nanocomposite was designed by the combination of thermally synthesized g-CN and ATO nanoparticles by ultrasonication. The materials were characterized using N2 adsorption/desorption(BET), X-ray diffraction(XRD), scanning electron microscopy(SEM), energy dispersive spectroscopy(EDS), transmission electron microscopy(TEM) and Fourier transform infrared spectroscopy(FTIR). A mixture of five volatile organic compounds(VOCs, chloroform, benzene, toluene, xylene and styrene) was used to compare the adsorption capacity of the samples. The adsorption capacity of ATO nanoparticles was improved by the addition of g-CN. Experimental data showed that, among the five VOCs,chloroform was the least adsorbed, regardless of the samples. The g-CN/ATO showed nearly three times greater adsorption capacity for the VOC mixture than pure ATO. The unchanged efficiency of VOC adsorption during cyclic use demonstrated the completely reversible adsorption and desorption behavior of the nanocomposite at room conditions. This economically and environmentally friendly material can be a practical solution for outdoor and indoor VOC removal.

关键词： Antimony-doped tin oxide(ATO) Graphitic carbon nitride(g-CN) Volatile organic compounds(VOC) Adsorption

Preparation of Li[Ni_(1/3)Co_(1/3)Mn_(1/3)]O_2 powders for cathode material in secondary battery by solid-state method

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Rare Metals 2006年第Z2期25卷 184-188页

作者： PARK Sook hee kang Chan Hyoung Department of Advanced Materials Engineering Korea Polytechnic University Shihung Kyonggi-do 429-793 Korea

Employing Li2CO3, NiO, Co3O4, and MnCO3 powders as starting materials, Li[Ni1/3Co1/3Mn1/3]O2 was synthesized by solid-state reaction method. Various grinding aids were applied during milling in order to optimize the synthesis process. After successive heat treatments at 650 and 950 ℃, the prepared powders were characterized by X-ray diffraction (XRD) analysis, scanning electron microscopy, and transmission electron microscopy. The powders prepared by adding salt (NaCl) as grinding aid exhibit a clear R3m layer structure. The powders by other grinding aids like heptane show some impurity peaks in the XRD pattern. The former powders show a uniform particle size distribution of less than 1 μm average size while the latter shows a wide distribution ranging from 1 to 10 μm. Energy dispersive X-ray (EDX) analysiss show that the ratio of Ni, Co, and Mn content in the powder is approximately 1/3, 1/3, and 1/3, respecively. The EDX data indicate no incorporation of sodium or chlorine into the powders. Charge-discharge tests gave an initial discharge capacity of 160 mAh·g-1 for the powders with NaCl addition while 70 mAh·g-1 for the powders with heptane.

关键词： lithium ion battery cathode materials layered structure solid-state method discharge density

Evaluation of the Mrp2-mediated flavonoid-drug interaction potential of quercetin in rats and in vitro models

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Asian Journal of Pharmaceutical Sciences 2019年第6期14卷 621-630页

作者： Ju-hee Oh joo Hyun Lee Young-joo Lee Division of Biopharmaceutics College of PharmacyKyung Hee UniversitySeoul 02447Republic of Korea Department of Life and Nanopharmaceutical Sciences College of PharmacyKyung Hee UniversitySeoul 02447Republic of Korea

Quercetin is a biologically active flavonoid that has been used as a popular health *** is reported that quercetin may cause flavonoid-drug interaction mediated by P-glycoprotein,the most predominant efflux *** this study,we comprehensively evaluated the potential of the pharmacokinetic interaction of quercetin mediated by multidrug resistance-associated protein 2(MRP2),another major efflux ***2-transfected MDCKII cells and LS174T cells were used to evaluate the potential inhibition and induction of MRP2 by quercetin in *** evaluate the induction effect of quercetin on Mrp2 in vivo,Mrp2 mRNA expression in rat liver,kidney,and small intestinal tissues was determined after the oral administration of quercetin(50,100,or 250 mg/kg)for seven ***2-mediated interaction potential was also evaluated by the pharmacokinetic study of phenolsulfonphthalein in rats after single or multiple doses of ***,the effect of quercetin on absorption of docetaxel,a P-glycoprotein and CYP3A4 substrate,was also *** inhibited the function of MRP2 at 10μM and induced the mRNA expression of MRP2 at 50μM in ***,at 100 mg/kg,quercetin markedly increased Mrp2 expression in the small intestine of ***,there was no significant change in phenolsulfonphthalein pharmacokinetics due to single-(50,100,or 250 mg/kg)or multiple-dose(50,100,or 250 mg/kg for seven days)quercetin *** contrast,a significant interaction caused by quercetin(100 mg/kg)was observed in the absorption of *** results suggested that although quercetin modulates the function and expression of MRP2 in vitro,it may have a low potential of Mrp2-mediated interaction and present negligible safety concerns related to the interaction.

关键词： Quercetin P-glycoprotein Multidrug resistance-associated protein 2 Pharmacokinetics Flavonoid-drug interaction

TGF-β2 downregulates osteogenesis under inflammatory conditions in dental follicle stem cells

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International Journal of Oral Science 2018年第4期10卷 232-243页

作者： Soyoun Um joo-hee Lee Byoung-Moo Seo Biotooth Engineering Lab Dental Research InstituteDental Regenerative BiotechnologyDepartment of Dental ScienceSchool of DentistrySeoul National University Biotooth Engineering Lab Department of Oral and Maxillofacial Surgery and Craniomaxillofacial Life ScienceDental Research InstituteSchool of DentistrySeoul ational University

Bone formation is important for the reconstruction of bone-related structures in areas that have been damaged by *** conditions such as those that occur in patients with rheumatoid arthritis, cystic fibrosis, and periodontitis have been shown to inhibit osteoblastic differentiation. This study focussed on dental follicle stem cells(DFSCs), which are found in developing tooth germ and participate in the reconstruction of alveolar bone and periodontal tissue in periodontal disease. After bacterial infection of inflamed dental tissue, the destruction of bone was observed. Currently, little is known about the relationship between the inflammatory environment and bone formation. Osteogenic differentiation of inflamed DFSCs resulted in decreased alkaline phosphatase(ALP) activity and alizarin red S staining compared to normal DFSCs. Additionally, in vivo transplantation of inflamed and normal DFSCs demonstrated severe impairment of osteogenesis by inflamed DFSCs. Protein profile analysis via liquid chromatography coupled with tandem mass spectrometry was performed to analyse the differences in protein expression in inflamed and normal tissue. Comparison of inflamed and normal DFSCs showed significant changes in the level of expression of transforming growth factor(TGF)-β2. Porphyromonas gingivalis(P.g.)-derived lipopolysaccharide(LPS) was used to create in vitro inflammatory conditions similar to periodontitis. The osteogenic differentiation of LPS-treated DFSCs was suppressed, and the cells displayed low levels of TGF-β1 and high levels of TGF-β2. DFSCs treated with TGF-β2 inhibitors showed significant increases in alizarin red S staining and ALP activity. TGF-β1 expression was also increased after inhibition of TGF-β2. By examining inflamed DFSCs and LPS-triggered DFSCs, these studies showed both clinically and experimentally that the increase in TGF-β2 levels that occurs under inflammatory conditions inhibits bone formation.

关键词： TGF downregulates osteogenesis under inflammatory conditions in dental follicle stem cells