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        검색결과 95

        23.
        2020.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        한국 땅나리와 섬말나리의 수요는 최근까지도 늘어났지만 종자 상태에서 개화에 이르기까지 확률은 낮은 편으로 자생지에서의 개체수는 해마다 감소하였다. 본 연구는 땅나리(Lilium callosum Siebold & Zucc.)와 섬말나리(L. hansonii Leichtlin ex D.D.T. Moore)의 대량증식을 도모하기 위하여 종자 발아에 유리한 주·야간 온도 조건과 적합한 GA3 농도를 알아보는 것을 목적으로 수행되었다. 땅나리 종자는 2017년 10월 24일 강원도 춘천히 둔산면 원창리(37°47’10.00”N, 127°44’31.00”E), 섬말나리 종자는 2017년 10월 2일 울릉도 울릉군 북면 나리 (37°31’27.06”N, 130°52’25.08”E)에서 채종하였다. 땅나리와 섬 말나리 종자들을 주·야간 15/5, 20/10, 25/15, 20/20°C의 환경 조절상에서 처리구 당 30립씩 3반복으로 치상하여 온도 처리 실험을 진행한 후, 발아율 결과가 가장 우세했던 온도 조건의 환경조절상에서 섬말나리 GA3 처리 실험을 추가로 진행하였다. 온도 처리 실험결과 땅나리는 20/20°C의 온도 조건에서 발아율이 95.0%로 가장 높았으며 평균발아소요일수 또한 10.1일로 가장 낮았다. 섬말나리는 20/20°C의 온도 조건에서 발아율이 78.8%로 가장 높았으며 평균발아소요일수 또한 40.1일로 가장 낮았다. 이를 토대로 20/20°C에서 실시한 섬말나리 GA3 처리 실험은 증류수를 대조구로하여 200, 400, 800mg・L-1의 농도로 상온에서 24시간 침지한 후 처리구 당 20립씩 3반복으로 치상하였다. 그 결과 대조구에서 81.6%로 가장 높은 발아율을 나타냈으며 평균발아소요일수는 200mg・L-1처리구에서 37.1일로 가장 낮았다. 이러한 실험 결과를 바탕으로 땅나리와 섬말나리의 주·야간 발아 최적 온도는 20/20°C이며 GA3 24 시간 처리는 섬말나리 종자 발아에 효과가 없는 것으로 판단 되었다.
        4,000원
        24.
        2020.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Fly ash consists of various metal oxides which can remove SO2 gas by the catalyst effect. When fly ash is added in the preparation process of pitch-based activated carbon, the pitch particles aggregate and fly ash is embedded in the activated carbon. To increase SO2 gas removal performance, activated carbon was prepared by surface-treated fly ash and petroleum-based pitch. Carboxyl groups were introduced into the fly ash by malic acid treatment. The introduced carboxyl groups acted as an activation agent to create micropore around the fly ash, and created micropores were exposed to the fly ash outside of the activated carbon. The exposed fly ash increased removal amount of SO2 gas by a catalytic effect of the metal oxides. The SO2 gas removal performance improved by 34% because of the catalyst effect of the exposed fly ash and improvement in the micropore structure in the activated carbon.
        4,000원
        25.
        2020.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        재생 불가능한 에너지 자원이 수년에 걸쳐 고갈됨에 따라, 재생 에너지 생산을 위한 보다 효과적인 방법에 대한 연구가 증가되었다. 연로전지 개발의 한 분야인 미생물 연료전지(MFC)는 이중 성능의 잠재력 덕분에 발전하였다. MFC는 박테리아와 같은 전극 감소 생물에서 전력을 모아서 전기 에너지를 생산한다. MFC는 폐수를 연료로 사용하여 에너지를 생산하고 폐수를 정화한다. 양성자 교환막(PEM)은 양극과 음극 챔버의 분리막으로, 양성자만 효과적으로 통과할 수 있게 하는 중요한 역할을 한다. Nafion은 MFC에 상업적으로 사용되는 PEM이지만 비용, 생산 시간, 양성자 전도성 차원에서 보완할 점들이 많다. 본 리뷰 논문에는 Nafion을 대체할 수 있는 새로 개발된 PEM 몇 가지를 논의하였다. 또한, PEM, 혼합 PEM 및 복합 PEM에 기반한 MFC를 요약하고자 한다.
        4,800원
        27.
        2020.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Hepatic stellate cells (HSCs) play essential roles in normal and pathophysiological function in liver. In steady state, HSCs contribute to retinoid storage, immune tolerance, and extracellular matrix (ECM) homeostasis. Upon liver injury, they become activated and lead to morphological and functional changes. Studies have demonstrated that activation of HSCs by various stimuli such as toxins, microbial infection, or metabolic overload can promote the fibrotic changes in liver by production of ECM. Herein, we provide current knowledge about the basic characteristics of HSCs and the mechanism by which they are activated.
        4,000원
        28.
        2020.06 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        Cancer is the second leading cause of death worldwide and currently there are many approaches developing towards cancer treatment. Cancer treatments like chemotherapy and radiation therapy are often painful and have adverse effects. The mechanism of apoptosis is a complex process and it involves different pathways in its mechanism of action. Apoptosis can be caused by signals within the cell such as stress, or by extrinsic signals such as ligands binding to cell surface death receptors. The programmed cell death plays a important role in the several physiological and pathological processes. It plays important role in homeostasis. Flavonoids have gained importance as anticancer agents promoting cytotoxicity and apoptosis in cancer cells. Flavonoids are present in many medicinal plants which are a kind of ubiquitous natural products and essential active ingredients. They have strong biological activities with high efficiency and low toxicity, possessing good preventive and cure effects on different tumor forms. Flavonoids such as Scutellarein, Pectolinarigenin and Naringin have reported to possess significant anti-cancer effects on different cancer cell lines till date. In this review, we provide a summary about the anti-cancer effect of the three flavonoids and its mechanisms of action that can be used in future for understanding their potent anti-tumor properties.
        4,000원
        29.
        2020.06 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        The development of drugs from natural plant sources is at growing interest due to the limitations of chemical drugs in terms of side effects and cost-effective factors of natural medicines. Among the various components contained in natural plant materials, flavonoids are of increasing interest because of their extended biological benefits. Flavonoids are classified into various types according to their structure and possess different activities depending on the structure. In this study, the flavonoids contained in Artemisia, native to Korea were examined and reviewed. HPLC chromatograms of three Artemisia species (Artemisia annua L., Artemisia iwayomogi and Artemisia argyi H.) were examined from published sources and their component analysis by MS data were summarized. The various flavonoids of Artemisia were classified into 12 types according to the main structure, and 10 flavonoids based on various activities were examined. The 10 flavonoids were identified as quercetin, kaempferol, rhamnetin, diosmetin, luteolin, methoxyflavone, catechin, apigenin, malvidin and genkwanin with extensive reported studies till date. The ten flavonoids examined have been reported to be effective in preventing and treating various diseases and exhibit activities such as anti-cancer, anti-inflammatory, antioxidant, antiviral, anti-obesity, anti-diabetic and anti-Alzheimer. The collective results from the reported studies suggest that the three types of Korean native Artemisia, contains various flavonoids with beneficial activities and may have therapeutic effects against diseases.
        4,200원
        32.
        2019.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        목 적:간 MRI 검사 시 호흡 정지 기법으로 검사를 진행하게 되는데 긴 검사시간으로 인해 호흡에 의한 움직임이나 불수의 적 움직임으로 영상의 질이 저하되는 경우가 빈번하다. 이런 이유로 영상의 질을 저하시키지 않으면서 검사시간을 단축시키기 위해 영상 획득 속도를 향상시키는 방법인 CS기법을 사용하고 있다. 본 연구에서는 CS기법의 extra reduction과 denoising level 조합의 변화에 따른 검사시간과 영상 변화를 기존의 conventional 3D-FFE THRIVE와 비교분석을 통하여 최적화된 parameter설정에 관하여 알아보고자 한다. 대상 및 방법:2018년 12월 1일부터 2019년 2월 3일까지 본원에서 간 MRI 검사를 시행한 환자 30명을 대상(남자 15명 여자 15명±6.73세)으로 extra reduction 1, denoising level 0% 가 적용된 3D-FFE THRIVE 시퀀스를 기존의 conventional 3D-FFE THRIVE로 간주하였으며, extra reduction level 1, 1.5, 2, 2.5, 3 값에 각각 denoising level을 0%, 20%, 40%, 60%, 80% 로 변화를 주고 다른 매개변수들은 모두 동일하게 하여 실험을 진행하였다. 획득한 각 영상들의 SNR, CNR, SSIM 을 측정하고, 정성적 영상 평가와 검사시간의 변화를 비교하였다. 정성적 평가에서 3점 이하로 평가받은 영상을 제외한 총 11개의 조합영상에 대하여 각 조합별로 순위를 매긴 후 1위는 1점, 11위는 11점으로 점수를 부여한 후, 합산 한 최종 점수가 가장 낮은 영상을 최적의 영상으로 선택하였다. 결 과:Extra reduction의 증가에 따라 SNR, CNR은 유의한 변화가 없었고, SSIM과 정성적 영상 평가 점수, 검사시간은 extra reduction증가에 따라 유의하게 감소하였다. Denoising level의 증가에 의해 SNR, CNR은 유의하게 증가하였고 SSIM과 검사시간은 유의한 변화가 없었으며, 정성적 영상 평가점수는 denoising level의 증가에 따라 유의하게 감소하였다. 결 론:본 연구의 실험결과를 종합해봤을 때 extra reduction 3, denoising level 20% 로 설정 시, 기존 영상 대비 정량적 평가인 SNR의 경우 12%, CNR의 경우 13% 향상되었으며, SSIM과 정성적 평가에서는 동일한 평가를 얻었고, 검사 시간은 50% 단축시키는 효과를 얻을 수 있었다. CS기법을 이용하여 간 검사 시, 시각적으로 용인되는 영상의 질 변화를 고려하여 extra reduction, denoising level을 조절한다면 화질의 유지와 함께 획기적인 검사 시간 단축을 이룰 수 있을 것으로 사료된다.
        4,000원
        33.
        2019.03 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        Inflammation is an important protective response mechanism that occurs against microbial invasion or injury. However, excessive inflammation may lead to cause of morbidity and mortality in diseases. The activated macrophages plays a vital role in inflammatory response by stimulation of lipopolysaccharide (LPS) and tumor necrosis factor-α (TNF-α). This activation further damages the host by inducing certain pro-inflammatory mediators such as nitric oxide (NO), interleukin-1β (IL-1β), interleukin- 6 (IL-6), TNF-α, inducible nitrous oxide (iNOS) and cyclooxygenase (COX-2). Flavonoids are bioactive compounds with potential effects as anti-cancer, anti-inflammation, anti-viral and anti-bacterial activities. Polymethoxyflavones (PMFs) are unique to citrus plants which are of specific interest owing to their biological effects that includes lipoprotein metabolism and anti-inflammatory activity. Sinensetin is one of the PMFs having five methoxy groups on the basic benzo-γ-pyrone skeleton with a carbonyl group at the C4 position. Sinensetin have been known for exerting various pharmacological activities including anti-angiogenesis, anti-diabetic and anti-inflammatory activities. However, there are no studies focused on the anti-inflammatory effects of sinensetin on skeletal muscle cells. In the present study, we investigated the antiinflammatory effect of flavonoids isolated from Sinensetin on the production of pro-inflammatory mediators mediated by nuclear factor-kappa B (NF-κB) by inhibition of signal transduction in LPS - induced L6 skeletal muscle cells.
        4,000원
        36.
        2018.05 구독 인증기관·개인회원 무료
        In the United States and Europe, new environmentally friendly asphalt pavement has been researched as an alternative to traditional hot asphalt pavement. After the Paris Convention of 2015, policies should be found to reduce carbon dioxide. In the field of asphalt pavement, new methods are needed to reduce carbon dioxide from the traditional hot asphalt pavement. In Korea, waste asphalt is growing and natural aggregate is running dry. So the government is implementing policies to increase the use of waste resources. So, it created a new asphalt pavement method to reduce CO2 and use waste asphalt. It is a cold recycled asphalt pavement. Emulsified asphalt has a balance of dispersibility, stability, and adhesive between water, aggregates, and asphalt. But, the physical properties of emulsified asphalt can be degraded compared to traditional hot asphalt pavement. So there are limitations in actual use. The study compared the softening point, elastic recovery, and penetration properties of asphalt mix compounds by using latex in emulsified asphalt. In particular, cations latex was used for the emulsified asphalt, which could further improve the physical properties.
        37.
        2018.05 구독 인증기관·개인회원 무료
        The composition of the deicer sprayed on the highway is spreading over the highway by the scattering or snow removal activity, or car movement and consequently affecting the vegetation environment around the highway. These are the cause of the damage of fruit trees and crops, and also the cause of corrosion of highway structures. The goal of this study is to estimate the detected range of deicer components from a highway. The concentration of the deicer components in gauze and soil were investigated according to the crossing distance from the highway. The data collected were then used to estimate the concentration range of deicer components in a rage of distance up to 100 m from the highway where the deicer was spread. The sample time and weight of gauze were measured before and after installation, and the soil was collected at more than three points in parallel with the highway at the gauze installation point. The components in gauze and soil were investigated in addition to the deicer components (Ca2+, Na+, Cl-) as well as Mg2+ and K+. As Ca2+ and Cl- components of deicer were affected by agricultural use, Na+ component was selected as a tracer and further SAR (Sodium Adsorption Ratio) of soil was analyzed to examine the degree of influence on vegetation indirectly. The gauze concentration was evaluated by the concentration of the deicer ingredient at the background concentration of the blank gauze. The total amount of the deicer sprayed in the study road for 4 months (winter season) was about 93 ton/km. In the gauze test, the spread of the deicer was detected at a distance of 100 m in study area, but the concentration of the deicer in the gauze by distance decreased rapidly within 10 m from the highway. And concentration of the deicer components in gauze and soil came down after rainy season (August ~ Sep.). The results showed that the components of the deicer could be spread widely by the wind. The effective range of the deicer on vegetation based on SAR in soil was estimated to be less than 20 m from the highway. This study examines the concentration changes of the deicer components in gauze and soils and shows that deicer components sprayed on the highway are accumulated and moved over time by wind, snow removal, terrain, water system and land use around the highway.
        38.
        2018.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 김치 제조시 철저한 재료 세척의 필요성을 확인하고, 더불어 비가열 식품인 김치의 위생 안전성 실태를 파악하여 효율적 미생물 저감화 방안을 마련하고자 국내에서 유통되는 김치 원·부재료 200건의 세척 전과 후의 비교분석과 시판 김치 100건에 대하여 미생물 분석을 실시하였다. 김치 원·부재료 및 완제품에 대하여 일반 세균수, 대장균 및 대장균군을 모니터링 하였으며, 병원성 미생물 9종(Bacillus cereus, Clostridium perfringens 정성·정 량, Staphylococcus aureus, Enterohemorrhagic Escherichia coli, Campylobacter jejuni/coli, Yersinia enterocolitica, Salmonella spp., Vibrio parahaemolyticus, Listeria monocytogenes 정성)을 분석 하였다. 모니터링 결과, 김치 원· 부재료 및 완제품에서 일반세균은 1.4~9.0 log CFU/g 수준 으로 확인되었으며, 원·부재료 중 생강에서 8.8 log CFU/g, 완제품 중 총각김치에서 9.0 log CFU/g으로 일반세균이 가장 높게 나타났다. 대장균군은 0.5~7.3 log CFU/g으로 확 인되었으며, 생강에서 7.3 log CFU/g으로 가장 높게 나타 났고, 병원성 미생물 9종의 분석결과, Bacillus cereus를 제 외한 나머지 8종의 식중독균은 모든 시료에서 검출되지 않았다. 김치 제조 시 사용되는 김치 원·부재료들의 세척 공정 후 미생물 수는 일반세균수 0.2~3.2 log CFU/g, 대장 균군 0.3~2.7 log CFU/g, Bacillus cereus 1.0~3.9 log CFU/g 감소하였다. 따라서, 김치 원·부재료의 세척 공정으로 미생물 오염도를 감소 시켰으며, 이 결과를 통하여 김치 완 제품의 위생 및 저장성 증진에 기여 할 수 있을 것으로 확인되었다.
        4,000원
        39.
        2018.04 구독 인증기관·개인회원 무료
        The effects of cold storage temperature and exposure duration on immature stages of spotted-wing drosophila (SWD) Drosophila suzukii (Diptera: Drosophilidae) on ‘Campbell Early’ grapes were examined to establish a phytosanitary control method. The immature stages (eggs, larvae and pupae) of SWD were all dead after a 6-day cold treatment at 1°C and 8-day cold treatment at 1.5 and 2°C. Small-scale tests using pupae, which were the most-cold tolerant stage, confirmed the validity of the selected temperature and exposure durations. Conversely, the 8- and 10-day at 1°C treatments showed 100% mortality, suggesting that these treatments can guarantee quarantine security against infestations of SWD on exported ‘Campbell Early’ grapes.
        40.
        2017.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The aim of this study was to select various fungal strains indigenous to Korea that have the potential to produce cellulases, including filter paper activity (FPase), endo-β-1,4-glucanase (EG), and β-glucosidase (BGL). Among the 25 species of Ascomycetes and the 32 species of Basidiomycetes tested in this study, the Bjerkandera adusta KUC10565, Heterobasidion orientale KUC10556, Hyphoderma praetermissum KUC10609, and Trichoderma harzianum KUC1716 all exhibited remarkably high FPase activity. In addition, the T. harzianum KUC1716 showed high levels of EG and BGL activity. This strain has been selected for further study because of their enzymatic potential.
        4,000원
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