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        검색결과 1,983

        1021.
        2017.03 구독 인증기관 무료, 개인회원 유료
        Microglia have multiple functions in regulating homeostasis of the central nervous system. Microglia cells have been implicated as active contributors to neuron damage in neurodegenerative disorders. In this study, medicinal plant extracts (MPEs) were used to evaluate the cell-death induction effect in microglia BV-2 cells. Among 35 MPEs tested in this study, 4 MPEs showed less than a 30% cell survival after 24 hours of incubation. These were Foeniculi Fructus, Forsythiae Fructus, Zingiberis Rhizoma and Hedera Rhombea. The concentration showed that 50% cell death (IC50) occurred with 33, 83, 67 Ed highlight: Please confirm wording, and 81 μ /ml, respectively. For further study, we chose Zingiberis Rhizoma (ZR) which showed a reasonably low IC50 value and an induction of cell death in a relatively narrow range. Western blot analysis showed that ZR-treated cells showed activation of caspase-3 and cleavage of PARP Ed highlight: When an acronym is first presented it needs to be spelled out in both dose- and time-dependent manners. However, the level of Bcl-2 and Bax were not changed by ZR-treatment in BV-2 cells. These results suggest that ZR-induced apoptosis in BV-2 cells occured through caspase-3 activation. The results also suggested that ZR may be useful in developing treatments for neurodegenerative diseases.
        4,000원
        1022.
        2017.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Some after-dinner thoughts on the giants of infrared space astronomy. I here describe important events in infrared astronomy starting from 1964 when I started working on my PhD. Here I describe how I became involved in IRAS, Infrared Space Observatrory (ISO), Herschel , Spitzer and AKARI, together with important events that led to these great missions.
        3,000원
        1023.
        2017.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The seaweed Ecklonia cava, a brown algae abundant in JeJu Island, South Korea, has large amounts of the polyphenol compound phloroglucinol (PG, 1,3,5-trihydroxybenzene), which has been proposed to exert interesting biological properties including antioxidant and radioprotective effects against ionizing radiation-induced damages in various cells and tissues. To identify antioxidant and radioprotective effects of PG in skin tissues, we exposed mice to 8.5 Gy whole body irradiation (WBI) at day 6 after depilation with and without PG treatment. In PG treated cases, PG was applied twice, once at 17.8 hours before and then at the time of WBI. At 8 hours after WBI, a reduction in the formation of thiobarbituric acid-reactive substrates (TBARS) was observed in the PG treated group. Upon western blot analysis, PG treatment overexpressed the MnSOD, catalase, and GPx-1, although the difference was not significant. In parallel with the results of western blot analysis, the percentage of MnSOD-and catalase-positive cells was significantly increased at 8 and 24 hours after WBI, while no significant difference was observed over 48 hours in PG treated skins. Moreover, PG treatment increased the percentage of Ki-67 positive cells compared with that of irradiated only mice at 8 hours after WBI. Our results suggest that PG is effective at attenuating oxidative stress, and that the promotion of antioxidant enzymes such as MnSOD and catalase may be an important aspect for its radioprotection in skin.
        4,300원
        1025.
        2017.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The objective of this study is the removal of chromium from tannery wastewater by electrosorption on carbon prepared from lignocellulosic natural residue "peach stones' thermally treated. The followed steps for obtaining coal in chronological order were: cleaning, drying, crushing and finally its carbonization at 900°C. The characterization of the carbon material resulted in properties comparable to those of many coals industrially manufactured. The study of the dynamic adsorption of chromium on the obtained material resulted in a low removal rate (33.7%) without applied potential. The application of negative potentials of -0.7 V and -1.4 increases the adsorption of chromium up to 90% and 96% respectively. Whereas a positive potential of +1.4V allows desorption of the contaminant of 138%.
        4,000원
        1026.
        2017.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We report the use of carrot, a new and inexpensive biomaterial source, for preparing high quality carbon dots (CDs) instead of semi-conductive quantum dots for bioimaging application. The as-derived CDs possessing down and up-conversion photoluminescence features were obtained from carrot juice by commonly used hydrothermal treatment. The corresponding physiochemical and optical properties were investigated by electron microscopy, fluorescent spectrometry, and other spectroscopic methods. The surfaces of obtained CDs were highly covered with hydroxyl groups and nitrogen groups without further modification. The quantum yield of as-obtained CDs was as high as 5.16%. The cell viability of HaCaT cells against a purified CD aqueous solution was higher than 85% even at higher concentration (700 μg mL−1) after 24 h incubation. Finally, CD cultured cells exhibited distinguished blue, green, and red colors, respectively, during in vitro imaging when excited by three wavelength lasers under a confocal microscope. Offering excellent optical properties, biocompatibility, low cytotoxicity, and good cellular imaging capability, the carrot juice derived CDs are a promising candidate for biomedical applications.
        4,000원
        1027.
        2016.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        The unique characteristics of graphene make it an optimal material for crucial studies; likewise, its potential applications are numerous. Graphene’s characteristics change with the number of total layers, and thus the rapid and accurate estimation of the number of graphene layers is essential. In this work, we review the methods till date used to identify the number of layers but they incorporate certain drawbacks and limitations. To overcome the limitations, a combination of these methods will provide a direct approach to identify the number of layers. Here we correlate the data obtained from Raman spectroscopy, optical microscopy images, and atomic force microscopy to identify the number of graphene layers. Among these methods, correlation of optical microscopy images with Raman spectroscopy data is proposed as a more direct approach to reliably determine the number of graphene layers.
        4,000원
        1028.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted to evaluate the effect of transfer temperature of epididymis on survival rate of semen and development ability of B6D2F1 mice embryos. No significant differences were noted in the survival rate of semen (59.0% ± 0.1 vs. 47.6% ± 0.1), in vitro fertilization rate (90.7% ± 0.1 vs. 90.7% ± 0.1), developmental rate (90.0% ± 0.1 vs. 90.0% ± 0.1), and blastocysts formation rate (53.1% ± 0.2 vs. 52.3% ± 0.2) between groups. (NS; P>0.05). However, the zona hatched rate was significantly higher in the 4°C group compared to those of the 37°C group (47.8% ± 0.1 vs. 25.6% ± 0.2; p<0.05). When it comes to cell numbers of blastocysts, the % ICM (/total cells) was significantly higher in the group of 4°C compared to the 37°C (27.0% ± 0.1 vs. 18.3% ± 0.1; p<0.05). However there were no differences in total cell numbers (72.7 ± 31.6 vs. 62.0 ± 36.6), ICM cell numbers (17.0 ± 7.8 vs. 14.6 ± 8.6), TE cell numbers (55.8 ± 29.8 vs. 64.0 ± 24.4), the ratio of ICM:TE (1:4.2 ± 4.1 vs. 1:6.4 ± 7.2) between two groups (NS; P>0.05).Taken altogether, it is expected to achieve the best developmental ability of B6D2F1 mice embryos in the transfer temperature of epididymis. Also these results can provide fundamental data to maximize culture condition for in vitro fertilization on B6D2F1 mice. In future, therefore, it is expected that results herein might be applied for in vitro culture of human embryos.
        4,000원
        1029.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 수박 접목묘의 활착에 미치는 상대습도의 영향을 알아보고자 수행하였다. 2품종(‘스피드’, ‘삼복꿀’)의 수박(Citrullus vulgaris Schrad.)을 ‘RS-동장군’ 박 대목(Lagenaria siceraria Stanld.)에 접목하고, 접목묘는 주간 25oC/야간 18oC, 광주기는 1일 16시간 기준으로 몰리어다이어그램을 따라 3수준의 상대습도, 95-96%[1.1-0.8(주간) 또는 0.8-0.6(야간) g·m-3수분부족분(VPD)], 97-98%[0.7-0.4(주간) 또는 0.5-0.3(야간) g·m-3 VPD], 또는 99-100%[0.3-0.0(주간) 또는 0.2-0.0(야간) g·m-3 VPD]로 유지하였다. 상대습도 처리 중 97-98% 처리는 대목과 ‘스피드’ 접수의 생체중과 초장을 가장 크게 증가시키며 접목 2일 후에 접합부의 연결을 향상시켰다. 그러나 ‘삼복꿀’의 경우 상대습도 99-100% 처리에서 경경과 초장이 증가하였다. 또한 상대습도 95-96%와 97-98% 처리에서 재배한 2 품종 모두 과산화수소가 덜 발생하고 산화적 스트레스의 지표인 항산화 효소의 활성이 덜 나타났다. 따라서 이 연구의 결과는 수박묘의 접목활착에 가장 적절한 상대습도는 97-98%였다.
        4,000원
        1030.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The efficacy of the natural amendments in improving physical condition as well as waterretention characteristics of the growing media in pot culture was studied on seven different mixratio of growing media applied to soil. Growing media was prepared from peat, perlite, pruningwaste, pulp(3:1:3:3(w/w/w/w)). Growth substrates were prepared by mixing growing media at therates of 0%, 10%, 20%, 30%, 40%, 50% and 100% with soil at 100%, 90%, 80%, 70%, 60%,50% and 0%, respectively. The bulk density tended to decreased with increasing growing mediaproportions. The particle density was lowest(0.6 g/cm3) in sole growing media treatment and theporosity of all the soil mixed growing media(63.2~83.3%) was significantly higher than that ofthe soil as sole medium(60.7%). The water content was lowest in sole soil treatment(5.1%) andgrowing media as sole medium(57.8%) was the closely ideal range for pot culture(>60%). Although substrates were varying water to the atmosphere at similar rates which retained waterfor longer, growing media as sole still remain constant on high water content. It was confirmedthat strongly correlated between bulk density and water retentivity(correlation-0.85).
        4,300원
        1032.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The reportedly synergistic effects of carbon nanotubes (CNTs) and graphene hybrids have prompted strong demand for an efficient modifier to enhance their dispersion. Here, we investigated the ability of poly(acrylonitrile) (PAN) to overcome the van der Waals interaction of multi-walled CNTs (MWCNTs) and graphene by employing a simple wrapping process involving ultrasonication and subsequent centrifugation of PAN/MWCNT/graphene solutions. The physical wrapping of MWCNTs and graphene with PAN was investigated for various PAN concentrations, in an attempt to simplify and improve the polymer-wrapping process. Transmission electron microscopy analysis confirmed the wrapping of the MWCNTs and graphene with PAN layers. The interaction between the graphitic structure and the PAN molecules was examined using proton nuclear magnetic resonance, ultraviolet-visible spectroscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis, and Raman spectroscopy. The obtained results revealed that the cyano groups of the PAN molecules facilitated adhesion of the PAN molecules to the MWCNTs and graphene for polymer wrapping. The resulting enhanced dispersion of MWCNTs and graphene was verified from zeta potential and shelf-life measurements.
        4,000원
        1033.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Activated carbon was synthesized from coconut shells. The Brunauer, Emmett and Teller surface area of the synthesized activated carbon was found to be 1640 m2/g with a pore volume of 1.032 cm3/g. The average pore diameter of the activated carbon was found to be 2.52 nm. By applying the size-strain plot method to the X-ray diffraction data, the crystallite size and the crystal strain was determined to be 42.46 nm and 0.000489897, respectively, which indicate a perfect crystallite structure. The field emission scanning electron microscopy image showed the presence of well-developed pores on the surface of the activated carbon. The presence of important functional groups was shown by the Fourier transform infrared spectroscopy spectrum. The adsorption of methyl orange onto the activated carbon reached 100% after 12 min. Kinetic analysis indicated that the adsorption of methyl orange solution by the activated carbon followed a pseudo-second-order kinetic mechanism (R2 > 0.995). Therefore, the results show that the produced activated carbon can be used as a proper adsorbent for dye containing effluents.
        4,000원
        1034.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        산업부산물인 석탄회을 이용하여 잘피군락의 조성 가능성을 평가하기 위한 현장실험을 실시하였다. 오염된 점토질 해저면에 석탄회 조립물을 이용하여 인공지반을 조성하고 잘피를 이식한 후 모니터링을 실시하였다. 이식된 잘피는 조성된 지반에서 성공적으로 정착하였으며, 이식 후 24개월 이후부터는 이식된 잘피의 개체길이의 증가 및 영양번식을 통한 잘피의 밀도의 빠른 증가가 확인되었다. 또한 조성된 잘피군락 및 그 주변에서 저서생물 및 미세조류의 종수가 증가하여 자연잘피군락과 동일하게 연안역의 생물다양성 향상에 도움이 되는 것을 확인할 수 있었다. 이상의 결과로부터 석탄회 조립물은 잘피군락 조성에 적합한 재료임을 확인하였다.
        4,000원
        1035.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구의 목적은 새로운 사고의 위기가 국내 해양안전에 미치는 영향을 분석하기 위함이다. 새로운 사고 위기는 세계 해상운송에서 새롭거나 드물게 또는 예측하지 못한 사건들로부터 유추한 것으로 사전 연구에서 46명의 전문가를 통해서 식별한 것이다. 새로운 해양사고의 위기를 식별하기 위하여 해양안전심판원(KMST)의 통계 데이터를 계산에 사용하였고, IMO의 공식안정성평가기법인 위기지수(RI) = 빈도지수(FI) + 심각성지수(SI)의 개념을 계산에 적용하였다. 통계적인 사고 데이터로부터 FI와 SI의 가중치를 계산한 후 가장 순위가 높은 시나리오를 식별하고 새로운 사고 위기와 시나리오 사이의 관계를 분석하였다. 분석 결과, 가장 순위가 높은 시나리오의 근본적인 원인은 “첨단기술 개발”이었고, 그 결과 “화물 작업 시간 단축”이 발생하는 것으로 나타났다. 이러한 결과는 사전 연구에서 46명의 전문가에 의해 식별한 “영업 경쟁” 및 “선원 문제” 등과 차이가 있음을 보였다.
        4,000원