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        검색결과 13

        3.
        2018.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 홍삼 유화 음료의 유통기한 예측을 위하여 수행하였다. 저장기간 동안 이화학적 특성 (산도, pH, 지방구크기, 색도) 및 관능적 특성의 변화를 주기적으로 조사하였다. 저장 초기에 홍삼 유화 음료의 산도, pH 및 지방구 크기는 거의 변화하지 않았으나 저장 후반기(70일 이후)에는 유의적으로 변화하 였으며 이는 주로 Maillard reaction 의한 것으로 추정하였다. 관능특성과 이화학적 특성들과의 상관분석을 통하여 색도 a 값(적색도)을 홍삼 유화 음료의 이화학적 품질지표로 설정하였다. Arrhenius 식에 의한 a값 변화에 대한 활성화 에너지 및 Q10-value는 각각 13.37 kcal/mol, 1.56-2.14로 조사되었으며, 홍삼 유화 음료의 유통기한은 상온(20℃) 보관의 경우 730일(약 2년)로 예측되었다.
        4,000원
        4.
        2017.11 구독 인증기관·개인회원 무료
        In South Korea, increase in kimchi import from China has emphasized the importance of noticing the origin of production area, largely because of the price and safety concerns. Nevertheless, identification of it depends on a complex physicochemical method. Hence, the objective of this study is to develop a statistical algorithm applicable for analyzing volatile compounds measured by electronic nose so that the device can be used for simple classification of kimchi by its production origin. Discriminant function analysis (DFA), one of multi-variate analysis, was mainly used for analyzing big-size data of volatile compounds detected from kimchi produced either in South Korea or China. Result showed that DFA could completely separate 69 varieties of kimchi by its origin of production (39 from South Korea and 30 from China). This result suggests that volatile compounds can be an index for identifying origin of kimchi and consequently, electronic nose is an optimal option for identifying origin of kimchi production when combined with multi-variate statistics.
        5.
        2017.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was carried out to extract ginsenosides in by-products from honeyed red ginseng. Response surface methodology (RSM) was used to optimize the extraction conditions. Based on D-optimal design, independent variables were ethanol (extraction solvent) concentration (30-90%, v/v), extraction temperature (25-70oC), and extraction time (5-11 h). Extraction yield (Y1) and total ginsenosides (Y2) in the extract were analyzed as dependent variables. Results found that extraction yield increased with increasing extraction temperature and time, whereas it was decreased with increasing ethanol concentration. Similar trends were found for the content of ginsenosides in the extracts, except for ethanol concentration, which was increased with increasing ethanol concentration. Regression equations derived from RSM were suggested to coincide well with the results from the experiments. The optimal extraction conditions for extraction yield and total ginsenosides were an extraction temperature of 56.94oC, ethanol concentration of 57.90%, and extraction time of 11 h. Under these conditions, extraction yield and total ginsenoside contents were predicted to be 84.52% and 9.54 mg/g, respectively.
        4,000원
        6.
        2015.06 구독 인증기관 무료, 개인회원 유료
        Curcumin (diferuloylmethane), a constituent of turmeric powder derived from the rhizome of Curcuma longa, has been shown to inhibit the growth of various types of cancer cells by regulating cell proliferation and apoptosis. However, a need exists to design more effective analogs because of curcumin's poor intestinal absorption. EF-24 (diphenyl difluoroketone), the monoketone analog of curcumin, has shown good efficacy in anticancer screens. However, the effects of curcumin and EF-24 on salivary gland epidermoid carcinoma cells are not clearly established. The main goal of this study was to investigate the effects of curcumin and EF-24 on cell growth and induction of apoptosis in human salivary gland epidermoid carcinoma cells. Our studies showed that curcumin and EF-24 inhibited the growth of HTB-41 cells in a dose- and time-dependent manner, and the potency of EF-24 was > 34-fold that of curcumin. Treatment with curcumin or EF-24 resulted in nuclear condensation and fragmentation in HTB-41 cells, whereas the control HTB-41 cell nuclei retained their normal regular and oval shape. Curcumin and EF-24 promoted proteolytic cleavages of procaspase-3/-7/-9, resulting in an increase in the amount of cleaved caspase-3/-7/-9 in the HTB-41 cells. Caspase-3 and -7 activities were detected in viable HTB-41 cells treated with curcumin or EF-24. These results suggest that the curcumin and EF-24 inhibit cell proliferation and induce apoptosis in HTB-41 human salivary gland epidermoid carcinoma cells, and that they may have potential properties as an anti-cancer drug therapy.
        4,000원
        7.
        2013.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study aimed to identify the recognition of fire risks on their field operations among firefighters and contribute to setting up safety measures accordingly. A self-administered questionnaire were used to evaluate their recognition of job risks. About 93.4% of respondents answered they have exposed to job risks and 73.4% answered that they had high safety awareness. Our study showed that the lower service years and ranks the fire officers had, the lower relevance in statistics their awareness of the risk of the field operations and safety concerns had. The vulnerable group is those aged 20 to 39, with under 10 years of service, at a lower rank of senior fire sergeant. The study suggests coming up with the measures to motivate the officers to perform safe operations by improving their safety awareness.
        4,000원
        8.
        2010.09 구독 인증기관 무료, 개인회원 유료
        The effects of chitosan upon the experimentally induced differentiation of MDPC-23 cells, derived from mouse dental papilla cells, were investigated by RT-PCR, observations of cell morphology and Alizaline red-S staining. Chitosan was found to significantly increase and accelerate the expression of ALP mRNA but decrease the ColI transcript levels, as compared with the control, in a time-dependent manner during the differentiation of MDPC-23 cells. Chitosan also significantly downregulated ON mRNA expression and accelerated mineralization in differentiating MDPC-23 cells. These results suggest that chitosan facilitates odontoblast differentiation and mineralization and may have potential clinical applications as a dentin regeneration material.
        4,000원
        9.
        2008.06 구독 인증기관 무료, 개인회원 유료
        A mutation of UNCL, an inner nuclear membrane RNAbinding protein, has been found to eliminate mechanotransduction in Drosophila. UNCL is expressed in human periodontal tissue including in periodontal ligament (PDL) fibroblasts. However, it is unclear how a mechanical stimulus is translated into cellular responses in PDL fibroblasts. The aim of this study was to evaluate the effect of UNCl on mechanical stress related genes in PDL fibroblasts in response to mechanical stress. The mRNA of TGF-β, COX-2, and MMP-2 was up-regulated after UNCL inactivation in PDL fibroblasts under the compression force. Under the tensile force, inactivation of UNCL decreased the expression of Biglycan, RANKL, MMP-2, and TIMP-2 mRNAs while it increased the expression of TIMP-1. p38-MAPK was expressed in PDL fibroblasts under compression forces whereas phospho-ERK1/2, p65-NFkB, and c-fos were expressed under tension forces. The expression and phosphorylation of the mechanical stress related genes, kinases, and transcription factors were changed according to the types of stress. Furthermore, most of them were regulated by the inactivation of UNCL. This suggests that UNCL is involved in the regulation of mechanical stress related genes through the signaling pathway in PDL fibroblasts.
        4,000원
        11.
        2018.11 KCI 등재 서비스 종료(열람 제한)
        본 연구의 목적은 해석적 방법을 통하여 내화 재료의 특성을 파악하고 섬유 강화 폴리머로 보강된 철근콘크리트의 보의 적절한 내화설계 방법을 제안하는 것이다. 이를 위해, 내화재료의 가열실험을 실시하고 유한요소해석을 통해 열전도율과 비열을 구하고 또한 고온에서 FRP로 보강된 철근콘크리트 보 실험체에 대한 유한요소 해석을 통해 실험결과와 해석결과를 비교하였다. 이 과정에서 실험과 해석적 접근의 신뢰성을 확인하였다. 최종적으로 FRP로 보강된 철근콘크리트 보의 열적특성을 제안된 해석 방법으로 분석하고 고온으로 감소된 휨내력을 계산하였다. 최종적으로 제안된 방법을 이용하여 FRP로 보강된 부재에서 고온 노출시 열특성을 반영한 부재의 열전도를 파악하고 이를 이용하여 내력을 산정할 수 있는 것으로 나타났다.
        12.
        2009.12 KCI 등재 서비스 종료(열람 제한)
        This study was performed to investigate the physico-chemical properties and phytoplankton concentration from February to December, 2007 in Gwangju area reservoirs. Water samples from 20 reservoirs were analyzed. As results of the water quality analysis, the average pH was 7.6 and annual pH were 6.3 ~9.6. The higher pH of 8.6 ~ 9.6 were showed from March to August due to eutrophication. Chlorophyll-a concentration ranged from 0.4 to 164.3 mg/㎥. The highest chlorophyll-a concentration was observed in August. BOD was correlated with SS, T-N, and Chlorophyll-a(R=0.82, 0.90 and 0.84) respectively. COD was correlated with BOD, SS and Chlorophyll-a(R= 0.89, 0.77 and 0.76) respectively. The T-N/T-P ratios were 4~281, so phosphorus was considered to be the limiting factor in most of points. The trophic state showed eutrophicate states in Gwangju reservoirs. Therefore it was necessary to monitor continuously. In order to monitor the reservoirs, an algae prediction system must be used.
        13.
        2008.01 KCI 등재 서비스 종료(열람 제한)
        6~13 ㎎/L base water concentration on monthly BOD has been kept at the Geukrak bridge point for this research target and it indicates the water quality under the existed rank. Due to this present condition of water quality, the demage of ecology from the upper stream to the lower one of the bridge could be conjectured. Moreover, nonstructural extinction of the ecology seems to have gotten worse between both the streams of Yeoungsan River. On this research, eco-corridor between the upper stream and the lower stream of the river should be ensured, the ecological demage needs to be cut off, a dispersed discharge method which the existed method of the 1st sewage plant in Gwangju was enhanced to should be inducted for the procuring of various water ecosystem, and the conditions by the scenario suggested from this research could be applied to a water quality model. then, analysis the improvement effect of the water quality adjacent the river. From the test result, Case3-Type1 scenario is thought to be the best one. From the test result with Case3-Type1, when the concentrated discharge was never done, 0.07 mg/L of BOD concentration was increased at the lower stream where Yeoungbon B point (Haksan Bridge) is but the water improvement effect of 0.24~2.87 mg/L is thought to have been done at the area of water deterioration.