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Segmented tomographic evaluation of structural degradation of carbon support in proton exchange membrane fuel cells

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Journal of Energy Chemistry 2022年第11期31卷 359-367,I0010页

作者： jung A.Hong min-Hyoung jung Sung Yong Cho Eun-Byeol Park Daehee Yang Young-Hoon Kim Sang-Hyeok Yang Woo-Sung Jang Jae Hyuck Jang Hyo June Lee Sungchul Lee Hu Young Jeong Young-min Kim Department of Energy Science Sungkyunkwan University(SKKU)Suwon 16419Republic of Korea Fuel Cell Core Parts Development Cell Hyundai Mobis Co.Ltd.Uiwang 16082Republic of Korea Electron Microscopy&Spectroscopy Team Korea Basic Science Institute(KBSI)Daejeon 34133Republic of Korea Graduate School of Semiconductor Materials and Devices Engineering Ulsan National Institute of Science and Technology(UNIST)Ulsan 44919Republic of Korea

The variation of the three-dimensional(3D)structure of the membrane electrode of a fuel cell during proton exchange cycling involves the corrosion/compaction of the carbon *** increasing degradation of the carbon structure continuously reduces the electrocatalytic performance of proton exchange membrane fuel cells(PEM-FCs).This phenomenon can be explained by performing 3D tomographic analysis at the ***,conventional tomographic approaches which present limited experimental feasibility,cannot perform such evaluation and have not provided sufficient structural information with statistical significance thus ***,a reliable methodology is required for the 3D geometrical evaluation of the carbon ***,we propose a segmented tomographic approach which employs pore network analysis that enables the visualization of the geometrical parameters corresponding to the porous carbon structure at a high *** approach can be utilized to evaluate the 3D structural degradation of the porous carbon structure after cycling in terms of local surface area,pore size distribution,and their 3D *** geometrical parameters of the carbon body were demonstrated to be substantially reduced owing to the cycling-induced *** information enables a deeper understanding of the degradation phenomenon of carbon supports and can contribute to the development of stable PEM-FC electrodes.

关键词： Electron tomography Fuel cell Proton exchange membrane Membrane electrode assembly Carbon corrosion

Long-term culture-induced phenotypic difference and efficient cryopreservation of small intestinal organoids by treatment timing of Rho kinase inhibitor

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World Journal of Gastroenterology 2017年第6期23卷 964-975页

作者： Sung-Hoon Han Sehwan Shim min-jung Kim Hye-Yun Shin won-Suk Jang Sun-Joo Lee Young-Woo Jin Seung-Sook Lee Seung Bum Lee Sunhoo Park Laboratory of Radiation Exposure and Therapeutics National Radiation Emergency Medical CenterKorea Institute of Radiological and Medical ScienceSeoul 01812South Korea

To investigate a suitable long-term culture system and optimal cryopreservation of intestinal organoid to improve organoid-based therapy by acquiring large numbers of *** were isolated from jejunum of C57BL/6 mouse. Two hundred crypts were cultured in organoid medium with either epidermal growth factor/Noggin/R-spondin1 (ENR) or ENR/CHIR99021/VPA (ENR-CV). For subculture, organoids cultured on day 7 were passaged using enzyme-free cell dissociation buffer (STEMCELL Technologies). The passage was performed once per week until indicated passage. For cryopreservation, undissociated and dissociated organoids were resuspended in freezing medium with or without Rho kinase inhibitor subjected to different treatment times. The characteristics of intestinal organoids upon extended passage and freeze-thaw were analyzed using EdU staining, methyl thiazolyl tetrazolium assay, qPCR and time-lapse live cell *** established a three-dimensional culture system for murine small intestinal organoids using ENR and ENR-CV media. Both conditions yielded organoids with a crypt-villus architecture exhibiting Lgr5+ cells and differentiated intestinal epithelial cells as shown by morphological and biochemical analysis. However, during extended passage (more than 3 mo), a comparative analysis revealed that continuous passaging under ENR-CV conditions, but not ENR conditions induced phenotypic changes as observed by morphological transition, reduced numbers of Lgr5+ cells and inconsistent expression of markers for differentiated intestinal epithelial cell types. We also found that recovery of long-term cryopreserved organoids was significantly affected by the organoid state, i.e., whether dissociation was applied, and the timing of treatment with the Rho-kinase inhibitor Y-27632. Furthermore, the retention of typical morphological characteristics of intestinal organoids such as the crypt-villus structure from freeze-thawed cells was observed

关键词： intestinal organoid Rho kinase inhibitor three-dimensional culture cryopreservation long-term culture

Phytoglycoprotein isolated from Dioscorea batatas Decne promotes intestinal epithelial wound healing

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Chinese Journal of Natural Medicines 2020年第10期18卷 738-748页

作者： KIM Ji-Yun LEE Young-min PARK Jong-Pil LIM Kye-Taek LEE Sei-jung Department of Pharmaceutical Engineering Daegu Haany UniversityGyeongsan 38610Republic of Korea Department of Food Science and Technology Chung-Ang UniversityAnseong 17546Republic of Korea Division of Animal Science Chonnam National UniversityGwangju61186Republic of Korea

Dioscorea batatas Decne(DBD)has been used to heal various illnesses of the kidney and intestine as an herbal medicine in *** a source of therapeutic agents,many glycoproteins have been isolated from mushrooms and plants,but the functional role of glycoprotein in intestinal epithelial wound healing has not been understood *** the present study,we investigated the wound healing potentials of the 30 kDa glycoprotein(DBD glycoprotein)isolated from DBD in human intestinal epithelial(INT-407)*** found that DBD glycoprotein(100μg·mL^-1)significantly increased the motility of INT-407 cells for 24 h by activating protein kinase C(PKC).DBD glycoprotein stimulated the activation of p38 mitogen-activated protein kinase(MAPK),which is responsible for the phosphorylation of NF-κB inhibitorα(IκBα).DBD glycoprotein increased the level of profilin-1(PFN1),α-actinin and F-actin expression via activation of transcription factor,nuclear factor-kappa B(NF-κB)during its promotion of cell *** mouse colitis was induced by adding dextran sulfate sodium(DSS)to the drinking water at a concentration of 4%(W/V)for 7 *** figured out that administration of DBD glycoprotein(10 and 20 mg·kg-1)lowers the levels of disease activity index and histological inflammation in DSS-treated ICR *** this regard,we suggest that DBD glycoprotein has ability to promote the F-actin-related migration signaling events via activation of PKC and NF-κB in intestinal epithelial cells and prevent inflammatory bowel disease.

关键词： Cell migration Dioscorea batatas Decne(DBD)glycoprotein Intestinal epithelial cells p38 MAPK F-actin Mouse colitis

A Flexible Database Security System using Multiple Access Control Policies

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A Flexible Database Security System using Multiple Access Co...

Combination of Korean Red Ginseng Extract and Hydrogen-Rich Water Improves Spermatogenesis and Sperm Motility in Male Mice

The Fourth International Conference on Parallel and Distributed Computing, Applications and Technologies

作者： min-A Jeong jung-Ja Kim Yonggwan won Research Institute of Electronics and Telecommunications Technology Chonnam National University 300 Yongbong-Dong Buk-Gu KwangjuREPUBLIC OF KOREA Department of Computer Engineering Chonnam National University 300 Yongbong-Dong Buk-Gu KwangjuREPUBLIC OF KOREA

＜正＞Due to various requirements for the user access control to large databases in the hospitals and the banks, database security has been *** are many security models for database systems using wide variety of policy-based access control ***,they are not functionally enough to meet the requirements for the complicated and various types of access *** this paper,we propose a database security system that can individually control user access to data groups of various sizes and is suitable for the situation where the user’s access privilege to arbitrary data is changed frequently. Data group（s） in different sizes d is defined by the table name（s）,attribute（s） and/or record key（s）,and the access privilege is defined by security levels,roles and polices. The proposed system operates in two *** first phase is composed of a modified MAC（Mandatory Access Control） model and RBAC（Role-Based Access Control） model.A user can access any data that has lower or equal security levels,and that is accessible by the roles to which the user is *** types of access mode are controlled in this *** the second phase,a modified DAC（Discretionary Access Control） model is applied to re-control the ’read’ mode by filtering out the non-accessible data from the result obtained at the first *** this purpose,we also defined the user group s that can be characterized by security levels,roles or any partition of *** policies represented in the form of Block（s,d,r） were also defined and used to control access to any data or data group（s） that is not permitted in ’read’ *** this proposed security system,more complicated ’read’ access to various data sizes for individual users can be flexibly controlled,while other access mode can be controlled as *** implementation example for a database system that manages specimen and clinical information is presented.

关键词： Database Security Access Control specimen and clinical information

来源： cnki会议评论

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Chinese Journal of Integrative Medicine 2020年第5期26卷 361-369页

作者： Ja Yoon Ku min jung Park Hyun Jun Park Nam Cheol Park Bo Sun Joo Department of Urology Pusan National University HospitalPusan National University School of MedicineBusan(49241)Republic of Korea Biomedical Research Institute Pusan National University HospitalBusan(49241)Republic of Korea The Korea Institute for Public Sperm Bank Busan(49241)Republic of Korea

Objective: To investigate the effect of hydrogen-rich Korean Red Ginseng(KRG) water(HRGW) mixture on the spermatogenesis and sperm motility of mice of different ages. Methods: Eighty young(3 month-old) and aged(12 month-old) male mice were randomly assigned to 4 groups(n=10 per group) including control group, hydrogen-rich water(HRW) group(10 m L/kg daily), KRG group(50 mg/kg daily) and HRGW group(10 m L/kg HRW and 50 mg/kg KRG daily) by an oral zoned needle for 4 weeks. Sperm count and motility were measured using sperm suspension released from cauda epididymis. Serum follicle stimulating hormone(FSH), luteinizing hormone(LH), testosterone, and reactive oxygen species(ROS) in serum have also been estimated. Tubular changes were examined through histological hematoxylin and eosin staining. Expression of antioxidation(PPx3, PPx4, GSTm5 and GPx4), spermatogenesis(inhibin-α, neptin-2 and CREM), antiaging(SIRT1 and SIRT2), and angiogenesis [visfatin and vascular endothelial growth factor(VEGF)] related genes were examined through realtime polymerase chain reaction. Results: HRW and KRG treatment stimulated spermatogenesis followed by increasing sperm production and sperm motility(P<0.05). These effects were strengthened synergistically by a HRGW mixture(P<0.05 or P<0.01). HRGW greatly increased the expressions of antioxidation, antiaging, spermatogenesis related genes and VEGF especially in aged mice(P<0.05). Serum testosterone and FSH levels also increased, while serum ROS level decreased(all P<0.05). Conclusion: HRGW increases sperm production and motility by enhancing antioxidation and stimulating spermatogenesis and sex hormone production, particularly in aged mice.

关键词： aging ginseng infertlit mineral waters sperm mtility

Diagnostic Indicators for Blood Stasis Syndrome Patients with Gynaecological Diseases

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Chinese Journal of Integrative Medicine 2018年第10期24卷 752-757页

作者： Jeeyoun jung Mi Mi Ko Myeong Soo Lee So min Lee Ju Ah Lee Korea Medicine Fundamental Research Division Korea Institute of Oriental Medicine Clinical Research Division Korea Institute of Oriental Medicine

Objective： To investigate the important diagnostic indicators for blood stasis syndrome （BSS） in patients of childbearing age with gynaecological diseases. Methods： A partial least squared-discriminant analysis （PLS-DA） were applied to BSS symptoms data of patients with gynaecological diseases, and the diagnostic indicators used by doctors of Korean medicine （DKMs） among BSS patients with gynaecological diseases were also investigated. Results： A total of 103 patients of childbearing age with gynaecological diseases and 40 healthy controls were enrolled. Among the 103 patients, 63 （61.7%） and 40 （38.8%） were diagnosed with BSS and non-BSS, respectively, and BSS patients exhibited a more severe extent of disease. A score plot of PLS-DA showed clearly different patterns among the 3 groups. Based on the variable importance on projection of PLS-DA model, menstrual pains, dark lumps in the menstrual blood, ileocoecal tenderness and resistance, sharp pains, and sublingual varicosities were selected as the top five most important indicators. Moreover, more than 75% of DKMs chose dark lumps in menstrual blood, menstrual pain, and dark menstrual blood as the diagnostic indicators of BSS in patients with gynaecological diseases, and more than 49% of them also considered sharp pains, dark red tongue, sublingual varicosities, and tendency to bruise easily as diagnostic indicators of BSS. Conclusion： DKMs focused on menstrual symptoms and certain gynaecological symptoms to diagnose BSS patients of childbearing age with female diseases.

关键词： blood stasis syndrome diagnosis gynaecological disease pattern identification

Polydopamine/carbon nanotube nanocomposite coating for corrosion resistance

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Journal of Materiomics 2020年第1期6卷 158-166页

作者： min-Sung Hong Yunjeong Park Teayeop Kim Kyunghoon Kim jung-Gu Kim School of Advanced Material Science and Engineering Sungkyunkwan University(SKKU)Suwon16419Republic of Korea School of Mechanical Engineering Sungkyunkwan University(SKKU)Suwon16419Republic of Korea

Carbon nanotube(CNT)has excellent properties as a coating ***,most methods for CNT coating have *** studies have shown that polydopamine(PDA)can be used as a good and eco-friendly corrosion resistance coating ***,the effect of PDA/CNT nanocomposite coating on the corrosion mitigation property of carbon steel(CS)remains ***,the objective of this study was to determine the effect of PDA/CNT nanocomposite coating on the corrosion mitigation property of carbon steel(CS).A dopamine(DA)/CNT composite was first *** length was controlled by *** on dynamic light scattering,field emission transmission electron microscopy,and atomic force microscopy analyses,average lengths of CNTs in long and short DA-CNTs were 500 and 50 nm,*** steel specimens were subjected to corrosion resistance analysis using electrochemical *** of electrochemical tests showed that corrosion resistance of CS coated with PDA and PDA/CNTs were dramatically higher than those of bare *** corrosion mitigation was attributed to two ***,PDA decreased the corrosion rate due to the generation of a thin and dense layer on the ***,CNTs suppressed the cathodic partial reaction due to oxygen adsorption at defect sites of CNTs.

关键词： Polydopamine(PDA) Carbon nanotube(CNT) Corrosion Coating Nanocomposite Electrochemical analysis

InIncidence and clinical features of endoscopic ulcers developing after gastrectomy

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World Journal of Gastroenterology 2012年第25期18卷 3260-3266页

作者： Woo Chul Chung Eun jung Jeon Kang-Moon Lee Chang Nyol Paik Sung Hoon jung jung Hwan Oh Ji Hyun Kim Kyong-Hwa Jun Hyung min Chin Department of Internal Medicine The Catholic University of KoreaSeoul 130-709South Korea Department of Surgery The Catholic University of Korea College of MedicineSeoul 130-709South Korea

AIM： To determine the precise incidence and clinica features of endoscopic ulcers following gastrectomy. METHODS： A consecutive series of patients who un- derwent endoscopic examination following gastrectomy between 2005 and 2010 was retrospectively analyzed. A total of 78 patients with endoscopic ulcers and 759 without ulcers following gastrectomy were enrolled. We analyzed differences in patient age, sex, size of the le- sions, method of operation, indications for gastric resec- tion, and infection rates of Helicobacterpylor/（H. pylor/~ between the nonulcer and ulcer groups. RESULTS： The incidence of endoscopic ulcers after gastrectomy was 9.3% and that of marginal ulcers was 8.6%. Ulcers were more common in patients with Billroth l] anastomosis and pre-existing conditions forpeptic ulcer disease （PUD）. Infection rates of H. pylori- did not differ significantly between the two groups. The patients who underwent operations to treat PUD had lower initial levels of hemoglobin and higher rates of hospital admission. CONCLUSION： H. pylori was not an important factor in ulcerogenesis following gastrectomy. For patients who underwent surgery for PUD, clinical course of mar- ginal ulcers was more severe.

关键词： Gastrectomy Marginal ulcer Helicobacterpylori

Fabrication of two-layer flexible copper clad laminate by electroless-Cu plating on surface modified polyimide

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中国有色金属学会会刊：英文版 2009年第4期19卷 970-974页

作者： Soo-min HWANG Jun-Hyung LIM Chang-min LEE Eui-Cheol PARK Jun-Hyuk CHOI Jinho JOO Hoo-Jeong LEE Seung-Boo jung School of Advanced Materials Science and Engineering Sungkyunkwan University

A flexible copper clad laminate(FCCL) was fabricated using electroless-and electro-Cu plating processes and the effects of pre-treatment time on the adhesion strength of the FCCL were evaluated based on interfacial *** neutralization and catalyst time were varied in the range of 0-20 min and 0.1-10 min,respectively,and the interfacial condition of the FCCL was characterized by atomic force microscopy(AFM) and X-ray photoelectron spectroscopy(XPS).It is observed that the peel strength increases significantly as the neutralization and catalyst time *** strength as high as 7.2-7.3 N/cm is obtained as the neutralization and catalyst time increase up to 20 min and 10 min,respectively,which is comparable to the strength achieved by the conventional laminating and sputtering *** improvements are probably due to an increase in the surface roughness of polyimide(PI),the activated surface condition,and the adsorption of palladium ions/atoms(Pd) on the PI surface which act as nucleation sites for Cu.

关键词：聚酰亚胺表面改性化学制备层压板铜电镀铜箔软性 X射线光电子能谱