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        검색결과 71

        42.
        2015.04 구독 인증기관·개인회원 무료
        Species diversity of ant fauna inhabiting the university campus in the Seoul Metropolitan city, Hanyang University is documented in this investigation. Totally, 14 species of 8 genera belong to 3 subfamilies discovered in study area. Our results are compared with the previous works on ant fauna in the forest and urban habitats based on species number difference. In study area, site 12 and 13 contain wide forest area and diverse environmental elements such as rotten wood, leaf mold and group of living tree. Site 7 has small forest area, but show wide variety of environments like site 12 and 13. Urbanized region like site 8, 10 or area in construction like site 1 show the most lowest diversity. Aside from diversity, Four ant species, Paratrechina flavipes, Lasius spp., Camponotus japonicas, Tetramorium caespitum, appear at almost all habitat, seems to have strong tolerance to environmental change.
        43.
        2013.10 구독 인증기관·개인회원 무료
        The centipede Scolopendra subspinipes mutilans has been a medically important arthropod species by using it as a traditional medicine for the treatment of various diseases. In this study, we derived a novel lactoferricin B like peptide (LBLP) from the whole bodies of adult centipedes, S. s. mutilans, and investigated the antifungal effect of LBLP. LBLP exerted an antifungal and fungicidal activity without hemolysis. To investigate the antifungal mechanism of LBLP, a membrane study with propidium iodide was first conducted against Candida albicans. The result showed that LBLP caused fungal membrane permeabilization. The assays of the three dimensional flow cytometric contour plot and membrane potential further showed cell shrinkage and membrane depolarization by the membrane damage. Finally, we confirmed the membrane-active mechanism of LBLP by synthesizing model membranes, calcein and FITC-dextran loaded large unilamellar vesicles. These results showed that the antifungal effect of LBLP on membrane was due to the formation of pores with radii between 0.74 nm and 1.4 nm. In conclusion, this study suggests that LBLP exerts a potent antifungal activity by pore formation in the membrane, eventually leading to fungal cell death.
        44.
        2013.04 구독 인증기관·개인회원 무료
        This study was carried out to clarify the response of butterfly communities on forest degradation in the Gwangneung Forest, Korea. We monitored butterfly communities with varying degrees of human activities by conducting line transect twice a month in 2011. A total of 70 species and 4,676 individuals butterflies were observed in four sites: natural forest, plantation forests, and Korean National Arboretum. Species richness increased with increasing open land. The result on niche breadth and habitat type of butterfly was consistent with our predictions; specialist species and forest interior species were abundant in natural forest, whereas generalist species and grassland species were abundant in Korea National Arboretum, the most modified area. Also, habitat breadth of butterflies clearly indicated the difference on the degree of forest degradation. Butterfly diversity associated with landscape patterns based on aerial photographs supported mosaic concept which indicates that species diversity increases as habitat heterogeneity and variability increase. Forest management plan that maintains various habitats and ensures grasslands is necessary to increase butterfly diversity in forest.
        47.
        2010.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 azoxymethane (AOM)과 dextran sodium sulfate (DSS)로 유도된 대장 발암과정에 대한 셀레늄의 방어 효과를 조사하였다. 셀레늄 결핍(0.02 ppm Se), 정상(0.1 ppm Se), 과다(0.5 ppm Se)사료를 12주간 식이로 급여하여 혈액검사와 대장암 발생의 초기단계인 aberrant crypt foci (ACF)수를 측정했으며, 암 발생율을 조사하였다. ICP-AES 를 사용하여 간의 셀레늄 농도를 측정하였으며, 또한 셀레늄포함 항산화효소인 glutathione peroxidase (GPx) 활성을 알아보았다. 또한 TUNEL assay와 PCNA, β-catenin에 대한 면역조직 염색을 수행하였다. ACF 수 및 종양 발생률에 있어서, 셀레늄과다사료를 급여한 군이 정상셀레늄사료를 급여한 군보다 낮았으며, 셀레늄결핍사료를 급여한 군은 오히려 ACF 수 및 종양 발생률이 높았다. GPx 활성은 셀레늄의 섭취가 과다한 군에서 높게 나타났으며, 이 때, TUNEL 에서 apoptotic positive cell이 증가하는 것을 확인했다. 또 한 셀레늄의 섭취가 과다한 군에서 PCNA와 β-catenin의 발현이 감소됨을 볼 수 있었다. 본 마우스 모델실험에서 셀레늄은 여러 기전에 의해 대장암 발생을 억제할 수 있을 것으로 사료된다.
        4,000원
        49.
        2007.04 KCI 등재 구독 인증기관·개인회원 무료
        [n order to obtain the trlle expected DNA prod uct from PCR and RT-PCR using genornic DNA or cDNA reversely transcribed from mRNA. the PCR should be done in an appropriated condition. Sometimes the PCR was repeatedly fail ed. and cventllally the PCR product was turned out to be nonspecific and rudimentary . And more‘ t he PCR prodllctwas not reproducible even though careflll repeat of experiments. As the PCR was based on the exact primel hybridization. the condition of primer hybridization should be properly controlled by a nnealing temperatllre. But the selection of primer seqllences for targeting a specific gene is mostly important. A new method of primer eval uation is now available llsing DNA base pair polarity program. This study presents an example of PCR targeting to human Bax gene using genomic DNA. The DNA base pair polarity theory can di vide the genetic cord into propel DNA segments and calclllaLe their DNA base pair hybridization energy. Thus. mathematically the degree 0(' exact primer hybridization can be expected for the t r1l8 targeting of PCR. However, the DNA base pair polal'ityanalysis demonstrates that the more frequent number of DNA segment incl'eased the specificity of PCR. but decreased its sensitivity . While the greater polarity of DNA segment composed of increased nllmber of polarized DNA base pairs showed increased sensitivi ty 0 1' PCR. bllt relati vely decreased specificity of PCR. With the mllltiple analysis of PCR. especially for PCR cloning from the gDNA and cDNA, we found that the primers themselves showed secondary strllcture of partial hybridization between sameprimers or each pair primers. The DNA base pail‘ polarity signal can directly demonstrated symmetric sequences 0 1' each primer. and also can distinguish the dimmer formation from each pair primers. At least the symmetric seqllence of fOlll‘ base pairs dramatically showed the dimrner formation. On the other hand. in addi tion Lo the statlls of DNA base pair polarity the three-dimensional strllctllre of DNA dOllble helix targeted by the primer seqllences may affect the sensitivity and specificity of PCR detection. The present study introduced a new method of primer evalllation and selection in order to obtain abundant and exacL! y-trlle DNA product for genomic ffilltation analysis and gene expression profï le
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