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        검색결과 5

        1.
        2020.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : The objective of this study is to figure out the trend and characteristics of fine particulate matter (PM2.5) and nitrogen oxide (NOx) concentration in underpass sections. The effect of traffic and meteorological condition on PM2.5 / NOx concentration was analyzed using field monitoring data. METHODS : Based on the literature review, PM2.5 and NOx concentration data were monitored using DustTrak II aerosol monitoring system and Serinus 40 oxides of nitrogen analyzer, respectively. Meteorological and traffic information was collected using automatic weather system and traffic volume counter, respectively. RESULTS : PM2.5 has a positive and negative correlation with relative humidity and wind speed, respectively. Meanwhile, NOx was found to have no correlation with meteorological conditions. The NO/NO2 ratio tends to change with traffic volume, indicating higher correlation between NO and traffic volume; the observed NO2 is mostly a secondary material produced by NO oxidation. CONCLUSIONS : Our study provides clear characteristics of NOx and PM2.5 and correlations with meteorological and traffic information in the underpass sections. It is found from this study that the increase in wind speed causes reduction in the concentration of PM2.5 owing to the diffusion and dispersion phenomena. On the other hand, the meteorological conditions were found to barely have correlations with NOx concentrations in this study. The traffic volume could significantly affect the NOx concentration and NO / NO2 ratio, which is directly correlated to the emissions from vehicles.
        4,000원
        2.
        2005.06 구독 인증기관 무료, 개인회원 유료
        Somatic cell nuclear transfer in cattle has limited efficiency in terms of production of live offspring due to high incidence of fetal failure after embryo transfer to recipients. Such low efficiency of cloning could possibly arise from abnormal and poorly developed placenta. In the present study the placental proteome in late pregnancy established from in vitro fertilization (IVF) and nuclear transfer (NT) was analysed. Proteome alternation was tested using two-dimensional polyacrylamide gel electrophoresis (2-DE) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI- TOF). Comparing placenta from NT embryos to those from IVF counterparts, significant changes in expression level were found in 18 proteins. Of these proteins 12 were not expressed in NT placenta but expressed in IVF counterpart, whereas the expression of the other 6 proteins was limited only in NT placenta. Among these proteins, cytokeratin 8 and vimentin are considered to be involved in regulation of post-implantation development. In particular, cytokeratin 8 and vimentin may be used as makers for placental development during pregnancy because their expression levels changed considerably in NT placental tissue compared with its IVF counterpart. Data from 2-DE suggest that protein expression was disorientated in late pregnancy from NT, but this distortion was eliminated with progression of pregnancy. These findings demonstrate abnormal placental development during late pregnancy from NT and suggest that alterations of specific placental protein expression may be involved in abnormal function of placenta.
        4,000원
        3.
        2016.05 서비스 종료(열람 제한)
        Background : Indigenous plant in Jeju island, Sasa quelpaertensis Nakai, belongs to the Bambusoideae and inhabit around Mt. Halla. According to the ancient book such as Dongui Bogam, Sasa quelpaertensis Nakai have been known to possess the antidiabetic, anti-inflammatory, and anti-diuresis effect. However, because of gradual upturning temperature, Sasa quelpaertensis Nakai was spread out to wider area and intrude the habitat that other plant species are growing. Recently, although the study to seek effective use of Sasa quelpaertensis Nakai, the investigation about functional properties has not been taken place enough. Methods and Results : To assess the inhibitory activity of melanin synthesis, we employ the tyrosine as substrate and measure the formation of dopaquione at 490 nm. Firstly, 0.1 mM potassium phosphate buffer and tyrosinase were mixed and incubated at 37℃. After incubating at 37℃, the absorbance rate was measured at 490 nm. The value was compared with positive control, arbutin, and calculated with the rate between sample and control value. Previously, formononetin, glabrene, glabridin, glabrol, artocarbene, dihydromoriin are known as effective substances for whitening. Moreover, the arbutin, which was separated from Arctostaphylos uva-ursi (L.) Sprengel, are widely used in cosmetic field. Arbutin inhibits tyrosinase and tyrosine synthesis, which induce blackish pigmentation. Practically, the Sasa quelpaertensis Nakai leaf ethanol extract depend on different solvent condition, whole extracts showed stronger inhibition than arbutin. Especially, 60% ethanol extract exhibited twice higher tyrosinase inhibitory activity than arbutin, whereas least inhibitory activity was seen in 20% ethanol extract. Conclusion : In this study, a attempt was made to investigate the tyrosinase inhibitory activity of Sasa quelpaertensis Nakai leaves extracted by different solvent condition. In the results, each extracts was prior to arbutin. Yet, 20% ethanol extract was lowest, but on the one hand, 60% ethanol extract demonstrated the highest tyrosinase inhibitory activity.
        5.
        2006.08 KCI 등재 서비스 종료(열람 제한)
        Research Institute (HARI), NTCS, RDA, in 2004. This cultivar has a short grain shape and about 123 days growth duration from trans-planting to harvesting under the reclaimed saline area of the south-western and the mid-western coastal plain and Honam plai