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        검색결과 110

        1.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Background: Canine induced pluripotent stem cells (iPSCs) are an attractive source for veterinary regenerative medicine, disease modeling, and drug development. Here we used vitamin C (Vc) to improve the reprogramming efficiency of canine iPSCs, and its functions in the reprogramming process were elucidated. Methods: Retroviral transduction of Oct4, Sox2, Klf4, c-Myc (OSKM), and GFP was employed to induce reprogramming in canine fetal fibroblasts. Following transduction, the culture medium was subsequently replaced with ESC medium containing Vc to determine the effect on reprogramming activity. Results: The number of AP-positive iPSC colonies dramatically increased in culture conditions supplemented with Vc. Vc enhanced the efficacy of retrovirus transduction, which appears to be correlated with enhanced cell proliferation capacity. To confirm the characteristics of the Vc-treated iPSCs, the cells were cultured to passage 5, and pluripotency markers including Oct4, Sox2, Nanog, and Tra-1-60 were observed by immunocytochemistry. The expression of endogenous pluripotent genes (Oct4, Nanog, Rex1, and telomerase) were also verified by PCR. The complete silencing of exogenously transduced human OSKM factors was observed exclusively in canine iPSCs treated with Vc. Canine iPSCs treated with Vc are capable of forming embryoid bodies in vitro and have spontaneously differentiated into three germ layers. Conclusions: Our findings emphasize a straightforward method for enhancing the efficiency of canine iPSC generation and provide insight into the Vc effect on the reprogramming process.
        4,000원
        2.
        2023.10 구독 인증기관·개인회원 무료
        금번 연구를 통해 외래산림해충 확산 분석 플랫폼 K-SDM (K-SDM)의 해충 분포 기능이 개발되었다. 해충 분포를 보여주는 기능은 2가지로 구현되며, 조사 자료를 바탕으로 현재 국내의 해충 분포를 나타내는 “외래산림 해충분포”기능과 데이터를 분석하여 예측되는 미래의 해충 분포를 제공하는 “외래산림해충예측”기능이 있다. “외래산림해충분포”는 조사자에 의해 현장에서 구축된 DB 현황을 지도상에 수치로 나타내며, 입력 기간, 해충 종 별로 구분이 가능하여 원하는 해충종의 분포를 선택하여 볼 수 있다. 지도 좌측에는 각 도별로 조사된 해충 개체수의 통계를 도표로 제공하여 수치상으로도 해충 분포를 파악할 수 있다. “외래산림해충예측”은 DB를 분석 하고 미래 기후 시나리오를 적용하여 도출한 미래의 해충 예측 분포도를 사용자에게 제공되며, 미리보기 이미지 와 함께 원본자료가 첨부되어 좀 더 자세한 정보를 열람할 수 있다. 본 플랫폼의 해충 분포 기능은 최근 기후변화 등으로 외래산림해충의 발생이 증가하는 추세에 맞춰 이들의 현재 분포와 미래의 분포양상을 조기 파악하여 이를 통한 추후 조기 방제 및 대응책 마련 등에 크게 기여할 것으로 기대된다.
        4.
        2023.10 구독 인증기관·개인회원 무료
        5.
        2023.04 구독 인증기관·개인회원 무료
        8.
        2021.03 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        The present study investigated Korean-accented English (KoE) intelligibility and conducted experiments in Korea, Japan, and the USA to test the benefits of listener’s familiarity and identify the key phonological features of KoE. In the experiments, the participants were asked to transcribe the target (KoE) of 100 English statements each containing a target word representing one of the nine features. The transcription data were administered to four groups, depending upon the degree of KoE familiarity (length of exposure). The results indicated that KoE was most intelligible to native English speakers with lower familiarity and least intelligible to the Japanese participants with low KoE familiarity. Although the listeners’ familiarity did not necessarily either facilitate or impede the intelligibility of KoE, the listeners with higher familiarity with KoE tended to recognize the voiced consonants of KoE better. The findings also indicated which KoE characteristics affected the overall intelligibility level, suggesting ways to prioritize KoE features in English language learning in Korean classrooms.
        6,100원
        14.
        2019.07 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        The purpose of this paper is to examine the intelligibility and attitude towards four English varieties to Korean-speaking learners (KSLs) of English, who have been exposed mainly to General American (or Korean-accented English) in their English language learning classrooms throughout the primary and secondary schools. A total of 105 Korean undergraduate students listened to a recording in one of the four accents (General American, British, Australian, and Korean-accented English) and completed an intelligibility test followed by a questionnaire survey on attitudes. Analysis revealed that British English was most intelligible to KSLs among four varieties whereas that of Australian was least intelligible. Attitudes toward an English variety did not exert a strong force that may contribute to the level of intelligibility. The findings also showed at which phonological features identified KSLs were most sensitive to intelligibility differences. We conclude that the more exposed English variety to KSLs, the more favorable attitudes can be formed, but is not necessarily intelligible. What the findings demonstrate is that attitudes are not the best explanation of intelligibility and call for improvement in ways of directing KSLs’ attention to some phonological features in a learnability perspective.
        5,700원
        15.
        2019.04 구독 인증기관·개인회원 무료
        본 조사지인 돌리네 습지보호지역은 경북 문경시 산북면 굴봉산 정상부에 위치하였으며, 물이 고이기 힘든 돌리네(doline) 지형에 형성된 희귀 습지이다. 뿐만 아니라 멸종위기종과 법적보호종이 분포하는 등 생물다양성 또한 매우 풍부한 것으로 평가되고 있다. 그러나 습지보호지역 주변으로 과수원 등 경작지가 형성되어 있어, 관리 및 보전을 위한 조사 및 대책이 필요하다. 따라서 본 조사에서는 습지보호지역의 체계적인 관리를 위하여 돌리네 습지의 곤충상을 조사하였다. 조사 방법에는 곤충의 다양한 습성과 서식환경을 고려하여, Searching, Sweeping, Pitfall trap, Bucket trap으로 총 4가지의 채집방법으로 조사를 실시하였다. 그 결과 총 11목 82과 188속 237종이 확인되었으며, 이중 딱정벌레목이 가장 많이 출현하였다. 특이사항으로 환경부지정종 51종(중복포함)이 조사되었으며, 그중 멸종위 기종 1종이 확인되었다. 본 연구를 통해 돌리네 습지보호지역의 곤충상을 파악하고 관리 및 보전에 대한 기초자료를 제공하고자 한다.
        16.
        2019.04 구독 인증기관·개인회원 무료
        The Celyphidae, commonly known as beetle flies or beetle-backed flies, are a family of Diptera. The scutellum is enlarged and forming a protective shell over the abdomen, giving them a beetle-like appearance. Species in the family are mostly found in tropical region, especially in South East Asia. Records of North East Asia are rare, in China, some species are found in Southern region. In Japan, few species found in Okinawa region, but only one record of Celyphidae near in mainland area. In this research we firstly record specimen of genus Spaniocelyphus sp., from Korea stored in National Science Museum Korea and Kyongpook National University with comparison of specimen from Tsushima island, Nagasaki prefecture stored in Osaka Natural History Museum.
        18.
        2018.11 구독 인증기관·개인회원 무료
        In our previous studies, the cardiac xenotransplantation from an alpha-1,3-galactosyltransferase knockout pig (GT-MCP-MCP) to cynomolgus monkeys showed a mean survival of 38 days. The objective of this study is to genetically upgrade the GT-MCP-MCP pig, to further enhance membrane cofactor protein (MCP) expression and to express an endothelial specific thrombomodulin (TBM). MCP is a complement regulatory protein and TBM is a coagulation inhibitor. As the dicistronic cassette for wild-type-based MCP and TBM concurrent expressions does not show any increase of MCP, we optimized the MCP codon usage (mMCP) and substituted mMCP for MCP. When the mMCP-TBM cassette was transfected to HeLa cells, we were able to find an increased expression of MCP and endothelial cell-specific TBM expression. The cassette was then transfected into ear-skin fibroblasts isolated from one-month-old #23-4 of a GT-MCP-MCP pig, and the cell populations expressing MCP were obtained by MACS cell sorting. We performed a single cell culture of the selected cells, and obtained clones over expressing 90% MCP. The cells of a clone were used as a donor for nuclear transfer and generated GT-MCP/-MCP/mMCP/TBM pig. The transgenic pig was confirmed to be carrying the cells expressing MCP and functioning as an inhibitor against the cytotoxic effect of normal monkey serum, comparable with donor cells. Thus, we believe that the GT-MCP/-MCP/mMCP/TBM transgenic pig would be potential for the prolongation of xenograft survival in the recipients.
        19.
        2018.10 구독 인증기관·개인회원 무료
        Gonggeom-ji is designated wetland protected area by the Ministry of Environment of Korea in 2011 because of it’s high biodiversity and historic value. It contains a reservoir, paddy and forest site which has diverse niches for insects. Three transect lines of 50m were designated. Data were collected in May, October, November in 2017 represented as seasons for spring, summer and autumn respectively. Quantitative methods were conducted along each transect line by sweeping and pitfall trap. Based on this study total of 1079 individuals of insect fauna were collected, representing 170 species in 60 families and 8 orders. The highest diversity, richness and evenness index were observed in the forest site in May(4.77, 8.6 and 0.91 respectively) and the highest dominance index was observed in the forest site in November(0.64). The highest similarity index was observed in the reservoir site in May and August(0.519).
        20.
        2018.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The aim of this study was performed to evaluate the effects of ice-binding protein from the arctic yeast Leucosporidium (LeIBP) supplementation on cryopreservation of boar sperm. The collected semen was diluted (1.5×108/ml) in lactose egg yolk (LEY) and cooled at 5°C for 3 h. The cooled semen was then diluted (1×108/ml) in LeIBP containing LEY with 9% glycerol and maintained at 5°C for 30 min. The semen was divided into six experimental groups (control, 0.001, 0.005, 0.01, 0.05 and 0.1 mg/ml of LeIBP). The straws were kept on above the liquid nitrogen (LN2) vapors for 20 minutes and then plunged into LN2. After thawing, computer-assisted sperm analysis was used for sperm motility and flow cytometry was performed to assess the viability, acrosome integrity (FITC-PSA/PI), ROS (DCF/PI), lipid peroxidation (BODIPY C11/PI) and apoptosis (Annexin V/PI), respectively. No significant responses were observed for sperm motility. However, sperm viability was significantly increased on 0.05 and 0.1 mg/ml of LeIBP groups compared to control (P < 0.05). In addition, acrosome integrity was significantly increases LeIBP groups (P < 0.05) and both ROS and lipid peroxidation level were lower in all LeIBP groups than those of control (P < 0.05). On the other hand, a significant higher apoptosis rate was observed in 0.05 and 0.1 mg/ml of LeIBP groups compared to control (P < 0.05). It can be assumed that a supplementation of LeIBP in boar sperm freezing extender is an effective method to increase the sperm qualities after cryopreservation.
        4,000원
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