검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 149

        122.
        2014.09 KCI 등재 서비스 종료(열람 제한)
        A comprehensive fractionation technique was applied to a set of water samples obtained along drinking water treatment process with ozonation and biological activated carbon (BAC) process to obtain detailed profiles of dissolved organic matter (DOM) and to evaluate the haloacetic acid (HAA) formation potentials of these DOM fractions. The results indicated that coagulation-sedimentation-sand filtration treatment showed limited ability to remove hydrophilic fraction (28%), while removal of hydrophobic and transphilic fraction were 57% and 40%, respectively. And ozonation and BAC treatment showed limited ability to remove hydrophobic fractions (6%), while removal of hydrophilic and transphilic fractions were 25% and 18%. The haloacetic acid formation potential (HAAFP)/dissolved organic carbon (DOC) of hydrophilic fraction was the highest along the treatment train and HAAFP/DOC of hydrophilic fraction was higher than hydrophobic and transphilic fraction as 23% 30%, because of better removal for hydrophobic fraction both in concentration and reactivity.
        124.
        2014.04 서비스 종료(열람 제한)
        The purpose of this study was to effects on flexural performance of SFRC prism with different fiber volume fraction. The test variables such as aggregate maximum size(8, 13, 20mm) and steel fiber volume faction(0, 1, 2%). Specimen size is 100×100×400mm and tested in for points loading. Test results indicated that increase the fiber volume fraction increase with flexural strength and smaller aggregate size more than higher performance with concrete.
        125.
        2013.10 KCI 등재 서비스 종료(열람 제한)
        This study was performed to determine the antimelanogenic effect and tyrosinase inhibitory activities of anthocyanin rich fraction (AN-SLP) from Liriope platyphylla Wang et Tang seeds. Anthocyanins isolated from L. platyphylla seeds revealed the presence of four major anthocyanin components, which were tentatively identified as delphinidin-3-Oglucoside, delphinidin-3-O-rutinoside, petunidin-3-O-rutinoside, and malvidin-3-O-rutinoside using semipreparative HPLC, 1H-NMR, 13C NMR, FAB-MS and LC/ES-MS. The inhibitory effect of AN-SLP on tyrosinase activity was studied using in vitro (against mushroom tyrosinase) and ex vivo (against B16 melanoma cell tyrosinase) models. Cellular tyrosinase activity was decreased by AN-SLP treatment in B 16 melanoma cells through dose dependent manner, but AN-SLP did not inhibit mushroom tyrosinase and L-DOPA oxidation directly. AN-SLP showed melanin inhibition by 53.2% at 50 μg/ml which was 0.7 times more efficient than the antimelanogenic effect of commercial arbutin and kojic acid (36.5%) also did not show cell toxicity. Additionally, AN-SLP inhibited the activity of α-glucosidase and the glycosylation of tyrosinase in melanoma cell. The resulting unsaturated glycosylation of tyrosinase makes it unstable and disturb correct transportation. From theses results, we conclude that AN-SLP could be used as anti-melanogenic agent for skin whitening.
        127.
        2013.10 서비스 종료(열람 제한)
        The purpose of this study is to estimate basic mechanical properties of steel fiber reinforced Alkali-Activated Slag(AAS) concrete. Principle variable is the fiber volume fraction: 0, 0.5, 1%. Two type cement composites were used: Steel Fiber Reinforced Concrete(SFRC) and AAS. Mechanical properties of AAS concrete and SFRC, including compressive strength, elastic modulus, flexural strength, splitting tension.
        131.
        2013.04 서비스 종료(열람 제한)
        This paper present results from effect of fiber volume fraction on direct shear property of steel fiber reinforced concrete(SFRC). Steel fiber with crimped end was used this work. Principal variable is fiber volume fraction; 0, 0.5, 1, 1.5, 2%, and aggregate size; 8, 13, 20mm. Specimen cross-sectional is 100 x 100 x 400mm. In order to induce the shear failure 2mm notch was sawed all around the specimen. Test result, there are little different between the aggregate size, and the improvements in shear strength of SFRC were more significant for 1% steel fiber volume fraction.
        132.
        2012.08 KCI 등재 서비스 종료(열람 제한)
        This study was performed to determined the antioxidant activities, anticancer and immuno-activities of anthocyanin fraction from Rubus coreanus Miquel fruits (Bokbunja). Anthocyanin fraction extracted from Bokbunja revealed the presence of three anthocyanin components, which were tentatively identified as cyanidin 3-O-sambubioside, cyanidin 3-O-xylosylrutinoside and cyanidin 3-O-rutinoside using RP-HPLC/DAD/MS. The anthocyanin fraction from Bokbunja always showed reducing power and high scavenging activities against DPPH, hydroxy radical (OH) and superoxide anion radical (O2-) similar to general synthetic antioxidant and polyphenol compounds from plant origin. Anthocyanin fraction from Bokbunja showed high inhibition on proliferation of LNCaP and A549 cells and did not inhibit the proliferation of other cancer cells. Immuno-activities of Anthocyanin fraction from Bokbunja were investigated, it showed high promotion of human B and T cells growth about 50% and secretion of IL-6 and TNF-α by treatment after 6 days. Over all, the result of the study suggest that anthocyanin fraction from Bokbunja displays antioxidant activity comparable to that general synthetic antioxidant, also, anthocyanin fraction from Bokbunja are expected to be good candidate for development into source of anticaner and immuno-activator agent in food industry.
        133.
        2012.06 KCI 등재 서비스 종료(열람 제한)
        This work aimed to elucidate the anti-inflammatory effects of ethyl acetate fraction from Cnidium officinale Makino with a cellular system of LPS-stimulated RAW 264.7 and THP-1 cells. Some key pro-inflammatory cytokines and mediators including NO, iNOS, PGE2, COX-2, TNF-α, NF-kB p50 and NF-kB p65 were studied by sandwich ELISA and western blot analysis. Ethyl acetate fraction could significantly inhibit the production of NO, PGE2, TNF-α, iNOS and COX-2 in LPS-stimulated cell than that of single LPS-stimulated. And ethyl acetate fraction suppresses the activation of NF-kB p50 and NF-kB p65. All the results showed that ethyl acetate fraction had a good anti-inflammatory effect on LPS-stimulated RAW264.7 and THP-1 cells. Taken together, the anti-inflammatory actions of ethyl acetate fraction from Cnidium officinale Makino might be due to the down-regulation of NO, PGE2, TNF-α, iNOS and COX-2 via the suppression of NF-kB activation.
        134.
        2011.10 KCI 등재 서비스 종료(열람 제한)
        본 연구의 목적은 cardiac MRI를 이용하여 확장기와 수축기의 정량적 측정을 통해 각 단면의 심박출률의 차이를 알 아보고자 하였다. 총 12명(정상 7명, 심근교 1명, 부정맥 4명)을 대상으로 심첨에서부터 대동맥궁 쪽으로 단면을 얻 었다. 수축기와 확장기 영상을 확대하여 경계를 정하였고, 이 면적을 바탕으로 1, 3, 5, 6-7단면의 심박출률을 구하였 다. 정상인의 평균 박출률은 각각 1, 3, 5, 6-7단면에서 67.14%, 66.24%, 65.63%, 그리고 65.29% 로 나타났다. 반 면. 환자들의 평균 박출률은 각각 1, 3, 5, 6-7단면에서 61.74%, 60.92%, 60.89%, 그리고 61.89%로 나타났다. 본 연구를 통해 cardiac MRI를 이용한 특정단면의 심박출률은 각 단면마다 큰 차이가 없음을 알 수 있었고 따라서 cardic MRI를 이용한 심박출계수의 평가는 대표 단면만으로 가능함을 알 수 있었다.
        135.
        2011.10 KCI 등재 서비스 종료(열람 제한)
        본 연구는 길경 사포닌 추출물(PGS)를 이용하여 대식세포의 면역조절능력을 평가하였으며, 탐식작용, 항암작용, 항염증 작용에 모두 유의적인 효과를 나타내었다. 특히, 본 연구에서는 농도의존적으로 매우 유의적이게 나타난 PGS의 항암작용 기전을 측정하기 위하여 암세포 독성 물질로 알려진 NO 분비량을 측정하였으며, PGS에 의해 NO의 생성을 증가함을 확인하였다. 또한, PGS가 NO 생성 억제제 NIL을 함께 처리하였을 때 항암효과가 나타나지 않게 됨을 재확인함으로써, PGS 10 μg/mL에서 나타낸 대식세포의 항암효과는 일부 NO 생성 및 분비에 의한 작용 기전임을 보여주었다. PGS의 면역조절작용 중 항염증효과 실험에서는 PGS가 염증환경에서 과도하게 분비된 NO를 다소 억제하는 경향을 보였으나, 항염증조절에서 대표적인 물질로 알려진 TNF-α 조절에는 효과를 나타내지 않았다. PGS가 염증환경에서의 TNF-α억제조절에는 영향을 미치지 않았으나 TNF-α는 항암물질로도 알려져 있으므로 향후 PGS의 항암효과에 대한 연구에서 TNF-α의 생성에 관한 연구는 NO를 매개하는 항암 효과 외에 다른 기전을 설명해줄 수 있을 것으로 보인다. 이러한 결과들은 PGS가 항암요법의 보조제 및 면역보조제로써의 활용에 개발 가능성이 있다는 것을 보여준다.
        136.
        2011.07 KCI 등재 서비스 종료(열람 제한)
        폴리프로필렌섬유보강 시멘트 복합재료와 구조용 합성섬유의 부착특성을 평가하였다. 폴리프로필렌섬유는 0.10%, 0.15% 및 0.20%의 체적비로 적용하여 dog-bone 시험을 실시하였다. 구조용 합성섬유와 폴리프로필렌섬유보강 시멘트 복합재료 사이의 부착강도는 폴리프로필렌섬유의 혼입률이 증가할수록 증가하였으나 0.20% 이상이 되면 감소하였다. 또한 폴리프로필렌섬유의 첨가는 계면인성과 마찰저항을 증가시킨다. 인발시험 후 구조용 합성섬유 표면의 미소구조 분석은 폴리프로필렌섬유의 혼입률이 증가할수록 긁힘 현상이 증가하였다.
        137.
        2010.12 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        청미래덩굴 뿌리(Smilacis rhizoma)로부터 칼슘과 결합하는 물질을 분리하고자 열수로 추출한 추출물을 ion exchange, normal-phase HPLC 및 gel filtration chromatogarphy를 이용하여 칼슘 결합 물질을 순차적으로 분리하였다. 그 결과 ion exchange chromatography에서 7개의 major peaks를 얻었으며, 이 중 F6 fraction이 0.083 mM로 칼슘과 가장 높은 결
        138.
        2009.08 KCI 등재 서비스 종료(열람 제한)
        This study was carried out to investigate the effect of Cinnamomum camphora on melanogenesis. The MeOH extract of Cinnamomum camphora inhibited mushroom tyrosinase activity in dose-dependent manner. Moreover, it significantly suppressed the melanin production in melan-a cells at the concentration of 100μ/ml. The MeOH extract was partitioned with ethyl acetate, n-butanol and water. Among them, the BuOH soluble fraction exhibited significant inhibitory effect on mushroom tyrosinase. In addition, the BuOH soluble fraction reduced the melanin production in melan-a cells. But, the BuOH soluble fraction had less inhibition effects on melan-a cell originated tyrosinase. So, it was performed western blotting for melanogenic proteins (tyrosinase, tyrosinase-related protein (TRP-2)) using melan-a cells. The BuOH soluble fraction inhibited the protein expression of tyrosinase at the concentration of 100μ/ml. The results suggested that the BuOH soluble fraction of C. camphora might be a potent inhibitor of melanin biosynthesis in melan-a cells.
        139.
        2008.06 KCI 등재 서비스 종료(열람 제한)
        In our previous study, ethylacetate fraction of white ginseng (root of Panax ginseng C.A. Meyer) extract inhibited mushroom tyrosinase activity and melanin production in melanocytes. This study examined its effects on the expression of melanin biosynthesis-related enzymes to explore the depigmenting pathway. Moreover, depigmenting effect on animal skin was examined using UV-B induced hyperpigmented skin of brown guinea pigs. The ethylacetate fraction of the white ginseng extract exhibited depigmenting activity in the skin of brown guinea pig without visible edema. In addition, this fraction reduced tyrosinase expression in melanocytes. The results suggested that ethylacetate fraction of white ginseng extract might be used as skin depigmenting material by inhibition of tyrosinase activity and expression.
        140.
        2008.03 KCI 등재 서비스 종료(열람 제한)
        월동 후 녹비용 호밀에 시용한 질소가 콩의 질소고정 및 흡수에 미치는 효과를 보기 위하여, 2004년 온실 및 2005년 포장에서 포트시험을 통해 시비질소량별 토양, 호밀 및 콩의 질소회수율을 조사하였다. 1. 2004년 온실폿트 시험에서는 호밀에 시용한 질소비료 량이 증가할수록 호밀지상부가 토양에서보다 질소비료로부터 질소를 흡수하는 비율이 증가하였다. 호밀이 없는 조건에서는 논흙이 밭흙보다 콩의 건물 중 및 질소흡수량이 현저히 증가하였는데, 지력이 높았던 논흙에서는 밭흙에 비해 콩이 질소고정 유래 질소의 비율이 상대적으로 낮아지고 토양유래 질소의 비율이 높았다. 2. 밭흙에서 무녹비와 대비하였을 때 호밀녹비 이용 시의 콩 시비질소회수율은 낮았지만 토양의 시비질소회수율(질소유기화)이 높아 전체회수율은 높았으며, 또 호밀녹비 이용시 콩의 시비질소회수율은 호밀에 대한 질소시용량이 많을수록 증가하였다. 3. 2004년 온실포트 실험에서의 콩의 근류고정유래의 질소비율은 약 92~95% 로 2005년 포장포트에서의 82~84% 보다 약 10% 정도 높았으며, 콩의 근류고정유래 질소량 및 질소량 분획 추정에서는 2년 모두 Difference method와 15N method간 차이를 보이지 않았다.
        6 7 8