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        검색결과 462

        61.
        2018.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Purpose: This study examined the effects of α-lipoic acid in diluted solvents on cell growth in 3T3-L1 cells according to the treated concentration and times. Methods: Adipocyte 3T3-L1 cell were cultured. Confluent cells underwent starvation with SFM for 1 day and then were cultured in a medium containing various concentrations 0, 100, 200, and 400 μmol/L of α-lipoic acid. The cell viability was measured using the EZ Cytox assay kit. In addition, the effect of α-lipoic acid of diluted solvents on the cell growth in 3T3-L1cells was examined according to the treated concentration and times. Results: The α- lipoic acid diluted ethanol inhibited cell proliferation in a dose and time dependent manner. The α-lipoic acid diluted ethanol induced adipocyte 3T3-L1 cells proliferation with an adipocyte inducer. In addition, α-lipoic acid inhibited adipocyte 3T3- L1 growth in a dose and time dependent manner (p<0.05). Conclusion: This study showed that a treatment with α-lipoic acid diluted ethanol inhibits cell growth of, adipocyte 3T3-L1 cells induced with an adipocyte inducer, (200 μmol/L of α- lipoic acid) treated for 48 hr.
        4,000원
        63.
        2018.09 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Lead free (1-x)(0.675BiFeO3-0.325BaTiO3)- xLiTaO3 (BFBTLT, x = 0, 0.01, 0.02, and 0.03, with 0.6 mol% MnO2 and 0.4 mol% CuO) were prepared by a solid state reaction method, followed by air quenching and their crystalline phase, morphology, dielectric, ferroelectric and piezoelectric properties were explored. An X-ray diffraction study indicates that lithium (Li) and tantalum (Ta) were fully incorporated in the BFBT materials with the absence of any secondary phases. Dense ceramic samples (> 92 %) with a wide range of grain sizes from 3.70 μm to 1.82 μm were obtained in the selected compositions (0 ≤ x ≤ 0.03) of BFBTLT system. The maximum temperatures (Tmax) were mostly higher than 420 oC in the studied composition range. The maximum values of maximum polarization (Pmax ≈ 31.01 μC/cm2), remnant polarization (Prem ≈ 22.82 μC/cm2) and static piezoelectric constant (d33 ≈ 145 pC/N) were obtained at BFBT-0.01LT composition with 0.6 mol% MnO2 and 0.4 mol% CuO. This study demonstrates that the high Tmax and d33 for BFBTLT ceramics are favorable for industrial applications.
        4,000원
        64.
        2018.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Acute vascular rejection has been known as a main barrier occurring in a xenograted tissue of alpha 1,3-galactosyltransferase knock-out (GalT KO) pig into a non-human primate (NHP). Adenosine which is a final metabolite following sequential hydrolysis of nucleotide by ecto-nucleotidases such as CD39 and CD73, act as a regulator of coagulation, and inflammation. Thus xenotransplantation of CD39 and CD73 expressing pig under the GalT KO background could lead to enhanced survival of recipient NHP. We constructed a human CD39 and CD73 expression cassette designed for endothelial cell-specific expression using porcine Icam2 promoter (pIcam2-hCD39/hCD73). We performed isolation of endothelial cells (pAEC) from aorta of 4 week-old GalT KO and membrane cofactor protein expressing pig (GalT-MCP/-MCP). We were able to verify that isolated cells were endothelial-like cells using immunofluorescence staining analysis with von Willebrand factor antibody, which is well known as an endothelial maker, and tubal formation assay. To find optimal condition for efficient transfection into pAEC, we performed transfection with GFP expression vector using four programs of nucleofection, M-003, U-023, W-023 and Y-022. We were able find that the program W-023 was optimal for pAEC with regard to viability and transfection efficiency by flow cytometry and fluorescent microscopy analyses. Finally, we were able to obtain GalT-MCP/-MCP/CD39/CD73 pAEC expressing CD39 and CD73 at levels of 33.3% and 26.8%, respectively. We suggested that pACE isolated from GalT-MCP/-MCP pig might be provided as a basic resource to understand biochemical and molecular mechanisms of the rejections and as an alternative donor cells to generate GalT-MCP/-MCP/CD39/CD73 pig expressing CD39 and CD73 at endothelial cells.
        4,000원
        65.
        2018.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 자색옥수수 색소 1호 포엽과 속대 추출물의 항비만 활성을 검정하고자 지방분해효소 저해활성을 평가 하고 3T3-L1 지방전구세포에서 지방분화억제 효과를 검정하고자 수행되었다. Pancreatic lipase 저해 활성 결과, 색소 1호 포엽 및 속대 추출물의 100, 500, 1,000 μg/mL 농 도처리구에서 양성대조군인 orlistat 보다 높은 저해 활성을 나타내었다. 3T3-L1 지방전구세포를 배양하여 색소 1 호 포엽 및 속대 추출물의 세포독성 평가를 수행한 결과, 추출물은 모든 처리농도에서 세포 생존율에 영향을 미치 지 않은 것으로 확인되었다. 분화된 3T3-L1 지방전구세포 에서 색소 1호 포엽과 속대 추출물을 처리하지 않고 분화 시킨 대조군은 lipid droplet의 형성이 활발하게 유발되었으나 색소 1호 포엽 및 속대 추출물의 처리에 의해 농도 의존적으로 lipid droplet의 형성이 억제되는 것으로 나타났다. Real-time PCR과 Western blot을 실시하여 PPARγ와 C/EBPα 유전자 및 단백질 발현량을 측정한 결과, 추출물을 처리하지 않고 분화시킨 대조군에서는 PPARγ와 C/ EBPα의 유전자 및 단백질 발현이 증가하였으며, 추출물 처리에 의해 PPARγ와 C/EBPα의 유전자 및 단백질 발현이 유의적으로 감소하였다. 본 연구 결과는 색소 1호 포엽 및 속대 추출물이 pancreatic lipase 활성 및 지방전구 세포의 분화를 억제시킴으로써 항비만 활성 기능성 물질 로의 활용 가능성이 높음을 시사한다.
        4,000원
        66.
        2018.04 구독 인증기관·개인회원 무료
        동남아시아에 발생하던 등검은말벌은 최근 국내 뿐만 아니라 프랑스와 일본, 유럽 전역으로 확산되어 전 세계 양봉 산업에 극심한 피해를 주고 있다. 등검은말벌을 방제하기 위해 다양한 방제 방법들이 연구되고 있으며, 그 중 말벌 유인제에 대해 국제적으로 많은 연구가 진행되어 왔으나 이 역시 지속적인 개발이 필요한 실정이다. 따라서 본 연구에서는 시판 유인제와 최근 (주)다목에코텍에서 새롭게 개발한 신규 개발 유인제에 대한 효능 검정을 수행하였 고 양봉장에 출현하는 국내 발생 말벌속의 발생양상을 조사하였다. 담양 1개소와 곡성 2개소에 기존 유인제과 신규 유인제를 장착한 포획기를 각 3쌍씩 설치하여 2016년 9월부터 11월말까지 주 1~2회 관찰하였다. 그 결과 국내 발생 말벌속 중 등검은말벌(7,787 개체)이 가장 많이 포획되었고, 다음으로 장수말벌, 말벌, 좀말벌, 꼬마장수말벌, 털보말벌 순으로 포획되었다. 두 유인제의 포획력 검정 결과, 신규 개발 유인제가 통계적으로 유의하게(P < 0.01) 등검은말벌 포획력이 높음을 보였다.
        67.
        2018.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 논문은 일제강점기 거국적인 민족운동으로 전개된 3·1운동과 여성독립운동을 세계평화의 시각에 대입하는 데 초점을 두고 있다. 일본 에 의해 국권을 상실했던 시기의 거국적인 민족운동으로 전개된 3.1운 동은 세계사적 관점에서 보면, 평화운동의 일환이었다. 특히 3·1운동은 민중운동으로서 계층과 지역, 성별의 구분을 넘어선 독립운동이었으며, 그 시대 독립운동이 지향한 독립과 자유에 대해 평화적 견지에서 재해석할 필요가 있다. 첫째, 그 시대가 당면했던 독립의 과제는 시대적·민족적 견지에서의 독립이었으며, 평화운동의 일환이었다. 둘째, 3·1운동에 참여한 여성은 주체의지로 독립운동의 참여자, 실천자로 변화했으며, 독립운동사 에서 한 주류로 한국여성독립운동의 맥락을 이어갔다. 셋째, 3·1운동은 국내는 물론 중국, 일본, 러시아, 유럽, 미주 등으로 확산되면서 아시아 약소국이 자유 의지를 발휘하는 데 영향을 주었고, 국내에서는 독립운동의 정신적 저력이 되었다. 이상에서 3·1운동은 세계평화의 관점에서 재인식되어야 하며, 3·1운동과 한국여성독립운동이 평화운동으로 주목받아야 할 것이 다.
        6,100원
        74.
        2017.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        (-)-Epigallocatechin-3-gallate (EGCG) is a major catechin found in green tea. It is reported that EGCG possesses various health benefits including anti-cancer, antioxidant, anti-diabetes, and anti-obesity. The objective of this study was to investigate the effects of EGCG on adipogenesis via activation of AMP-activated protein kinase (AMPK) pathway in 3T3-L1 preadipocytes. In order to determine the effects of EGCG on adipogenesis, preadipocyte differentiation was induced in the presence or absence of EGCG (0~100 μM) for a period of 6 days. EGCG significantly inhibited fat accumulation and suppressed the expression of adipogenic specific proteins including peroxisome proliferator-activated receptor (PPAR)-γ. Also, EGCG markedly increased the activation of AMPK and acetyl-CoA carboxylase (ACC) and the production of intracellular reactive oxygen species (ROS). However, any pretreatment with a specific AMPK inhibitor, compound C, abolished the inhibitory effects of the EGCG on PPARγ expression. This study suggests that EGCG has anti-adipogenic effects through modulation of the AMPK signaling pathway and therefore, may be a promising antiobesity agent.
        4,000원
        75.
        2017.09 구독 인증기관·개인회원 무료
        76.
        2017.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Tissue engineering (TE) has been developed to create functional organs and tissue by combining 3D matrix and cells in vitro. Vascularization and angiogenesis are utmost important for supply of nutrients and oxygen in tissue engineered organs. The present study was performed to isolate and characterize primary endothelial cells (EC) from aorta of alpha 1, 3-enzyme galactosyltransferase knock out (GalT KO) pig, to minimize immune rejection and analyze body immune system for future xenotransplantation studies. Isolation of primary EC from aorta were performed by incubation with dispase for 8-10 min at 37°C. Primary EC were cultured in EC growth medium on different extra cellular matrix (ECM), either collagen or gelation. Primary EC exhibits morphological characteristics and showed positive expressions of EC specific marker proteins i.e. PECAM1, KDR and VWF despite of their ECM surface; however, on collagen based surface they showed increase in mRNA level analyzed by qPCR. Primary EC cultured on collagen were sorted by flow cytometer using KDR marker and cultured as KDR positive cells and KDR negative cells, respectively. KDR positive cells showed dramatically increased in PECAM1 and VWF level as compared to KDR negative cells. Based on the above results, primary EC derived from GalT KO are successfully isolated and survived continuously in culture without becoming overgrown by fibroblast. Therefore, they can be utilize for xeno organ transfer, tissue engineering, and immune rejection study in future.
        4,000원
        77.
        2017.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Transplantation is considered to be a very useful approach to improve human welfare and to prolong life-span. Heterologous organ transplantation using pig organs which are similar to human beings and easy to make mass-production has known as one of the alternatives. To ensure potential usage of the pig organ for transplantation application, it is essentially required to generate transgenic pig modifying immuno-related genes. Previously, we reported production of heterozygous α 1,3-galactosyltransferase (GalT) knock-out and human membrane cofactor protein (MCP) expressing pig (GalT-MCP/+), which is enforced for suppression of hyperacute and acute immunological rejection. In this study, we reported generation of homozygous pig (GalT-MCP/-MCP) by crossbreeding GalT-MCP/+ pigs. Two female founders gave birth to six of GalT-MCP/-MCP, and seven GalT-MCP/+ pigs. We performed quantitative real-time PCR, western blot, and flow cytometry analyses to confirm GalT and MCP expression. We showed that fibroblasts of the GalT-MCP/-MCP pig do not express GalT and its product Gal antigen, while efficiently express MCP. We also showed no expression of GalT, otherwise expression of MCP at heart, kidney, liver and pancreas of transgenic pig. Taken together, we suggest that the GalT-MCP/-MCP pig is a useful candidate to apply xenotransplantation study.
        4,000원
        78.
        2017.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        이산화탄소 분리를 위해 이온성 액체/금속 산화물 복합막이 제조되었으며, 이온성 액체로서 1-butyl-3-methylimidazolium tetrafluoroborate (BMIM+BF4 -)와 금속산화물로서 Al2O3가 사용되었다. 13 nm의 Al2O3가 이온성 액체 BMIM+BF4 - 에 도입되었을 때, 복합체 분리막의 성능은 CO2/N2 선택도 30.5과 CO2 투과도 45.7 GPU로 관찰되었다. neat BMIM+BF4 - 분 리막의 성능(CO2/N2 선택도 5와 CO2 투과도 17 GPU)에 비해서 성능이 증가한 이유는 Al2O3의 옥사이드 층과 이온성 액체 내 자유로운 이온농도의 상승으로 인해 CO2 용해도가 상승한 것으로 확인되었다. 특히 Al2O3 나노입자는 질소 기체에 대해 서 장애물로서 작용함으로써 질소기체의 투과도가 감소하여 결과적으로 이산화탄소 분리 성능은 급격히 증가하였다.
        4,000원
        79.
        2017.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We fabricate fine (<20 μm) powders of Bi0.5Sb1.5Te3 alloys using a large-scale production method and subsequently consolidate them at temperatures of 573, 623, and 673 K using a spark plasma sintering process. The microstructure, mechanical properties, and thermoelectric properties are investigated for each sintering temperature. The microstructural features of both the powders and bulks are characterized by scanning electron microscopy, and the crystal structures are analyzed by X-ray diffraction analysis. The grain size increases with increasing sintering temperature from 573 to 673 K. In addition, the mechanical properties increase significantly with decreasing sintering temperature owing to an increase in grain boundaries. The results indicate that the electrical conductivity and Seebeck coefficient (217 μV/K) of the sample sintered at 673 K increase simultaneously owing to decreased carrier concentration and increased mobility. As a result, a high ZT value of 0.92 at 300 K is achieved. According to the results, a sintering temperature of 673 K is preferable for consolidation of fine (<20 μm) powders.
        4,000원
        80.
        2017.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        It is very difficult to get the information about semen quality analysis in transgenic pigs because of limited numbers and research facilities. Therefore, in the present study, we analyzed the semen quality of transgenic boars generated for xenotransplantation research. Briefly, the semen samples were collected from 5 homozygous α1,3-Galactosyltransferase knock-out (GalT-/-) transgenic boars and immediately transported to the laboratory. These semen samples were decupled with DPBS and conducted to analyze semen parameters by a computer-assisted semen analysis (CASA) system. The boar semen were examined all 12 parameters such as total motility (TM), curvilinear velocity (VCL), straight line velocity (VSL), average path velocity (VAP), and hyperactivated (HYP), etc. In results, among the 5 GalT-/- boars, three boars (#134, 144, and 170) showed normal range of semen parameters, but #199 and 171 boars showed abnormal ranges of semen parameters according to standard ranges of semen parameters. Unfortunately, #171 boar showed azoospermia symptom with rare sperm counts in the original semen. Conclusively, assessment of semen parameters by CASA system is useful to pre-screening of reproductively healthy boar prior to natural mating and artificial insemination for multiplication and breeding.
        4,000원
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