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        검색결과 45

        21.
        2014.04 구독 인증기관·개인회원 무료
        The Riptortus-Burkholderia symbiosis is a newly emerging insect-bacterium symbiotic system. This symbiosis system has a good merit as an experimental model system to produce the non-symbiotic (apo) and symbiotic (sym) host insect. In recent reported papers, the symbionts play important biological roles for the host insects. Meanwhile, juvenile hormone (JH) is one of major hormone synthesized corpora allata(CA) to control many physiology of insect. However, the study for cross-talk mechanism between symbionts and host hormones to control important physiological phenomenon of insects is almost none. In this study, we found that Riptortus speed up adult emerging and increase egg laying on presence of symbiont Burkholderia. Also we found that hexamerin proteins, which were controlled the expression by JH, were accumulated in sym-Riptortus hemolymph compare with apo-Riptortus. According as combined results, we hypothesized that the gut symbiont Burkholderia can control JH titer to conclude out beneficial effects such as development and reproduction of R. pedestris. To verify this hypothesis, we examined measurement of JH titer, expression of hexamerins as JH response genes and RNAi for hexamerin protein during whole Riptortus life on presence or absence of symbiont Burkholderia. All results demonstrated that gut symbiont controlled JH titer of Riptortus. Controlled JH amount by symbiont Burkholderia in host midgut regulated hexamerin protein expression for speeding up adult emerging and increasing egg production.
        22.
        2014.04 구독 인증기관·개인회원 무료
        Urbanization is one of the leading causes of habitat loss, habitat degradation, and fragmentation. Urban development negatively affects biodiversity. This study aimed to clarify the change of butterfly communities on effect of urbanization in urban green areas. Butterfly survey was conducted using the line transect methods from April to October in 2012. A total of 59 species and 1,465 individuals of butterflies were observed in four urban green areas: Namsan Park (NS), Ewha Womans University (EW), Bukseoul Dream Forest (BD), and Hongneung Forest (HF), and natural forest: Gwangneung Forest (GF). The category of land use around study site was determined based on GIS data. Species richness and abundance of niche breadth and habitat type in urban green areas differed significantly from those in GF. Estimated species richness and species diversity (H’) in four urban green areas were significantly lower than those in GF. Species richness and abundance of forest interior species and specialist were positively correlated with paddy, field, and forest, whereas those of forest interior species and specialist were negatively correlated with urban area and road. Butterfly communities in four urban green area differed from that in GF. The result suggests that the decrease of paddy, field, and forest associated with increase of urban area and road negatively influences species composition and changes butterfly communities.
        23.
        2013.12 구독 인증기관 무료, 개인회원 유료
        To profile the proteome in porcine plasma, blood samples were collected from adult male barrows and those plasma were retrieved. For the depletion or pre-fractionation of high-abundance proteins, plasma samples were treated with commercial kits. Then, protein profiling was initiated using one and two-dimensional electrophoresis. Proteins were spotted and then identified by MALDI-TOF-TOF and LC-MS-MS. In the results, more than forty six proteins were identified and the reference map was constructed. The pre-treatment for the removal of high-abundance proteins caused the changes in 2-DE images and some of the proteins were newly uncovered after the most of high abundant proteins were removed. However, it is expected for further steps necessary to identify more low-abundance proteins that may contain potential bio-markers.
        4,000원
        24.
        2013.12 구독 인증기관 무료, 개인회원 유료
        Here, we present an approach of blood plasma proteome profiling and their comparisons between the young and the adult pigs as prerequisite for the identification of bio-markers related to the health conditions, growth performance and meat quality. To profile the proteome in porcine plasma, blood samples were collected from 19 young piglets and 20 adult male barrows and the plasma was retrieved. Then, protein profiling was initiated using one and two-di-mensional electrophoresis. Proteins were spotted and then identified by MALDI-TOF-TOF and LC-MS-MS. In the re-sults, more than thirty-six and twenty eight protein spots were selected in young piglets and adult pigs, respectively and twenty three proteins were identified. The proteome profile images were compared between those ones using Image Master Version 7.0. The image of expressed proteome showed that most of proteins from plasma of young pig-let separated clearly and concentrated in 2DE display compared to ones from adult. Image analysis in detail was car-ried out to look for the specific proteins related to age progression. It demonstrated that the characteristics of proteome expression could be distinct to their age stages. Further investigations needed to proceed to understand the age de-pendent change of protein conformation and biological meaning of those differences in proteome expression between young and mature adult pigs.
        4,000원
        26.
        2013.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Needle coke is an important material for graphite electrodes. Delayed coking is used to produce needle coke. Producing good quality needle coke is not simple because it is a multi-parameter controlled process. Apart from that, it is important to understand the mechanism responsible for the delayed coking process, which involves mesophase formation and uniaxial rearrangement. Temperature and pressure need to be optimized for the different substances in every feedstock. Saturate hydrocarbon, aromatic, resin and asphaltene compounds are the main components in the delayed coking process for a low Coefficient Thermal Expansion value. In addition, heteroatoms, such as sulphur, oxygen, nitrogen and metal impurities, must be considered for a better graphitization process that prevents the puffing effect and produces better mesophase formation.
        4,000원
        27.
        2011.03 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        에멀션 기반의 계면활성제를 이용한 주형합성법을 이용하여 산촉매로서 염산과 실리카의 전구체인 테 트라에톡시실란을 사용함으로써 메조다공성 실리카 마이크로스피어를 합성하였다. 테트라에톡시실란의 농도 증가에 의해 구형의 입자 형태가 파괴되었고, 기공구조도 크게 변하였다. 산촉매 농도 증가에 의한 구형의 입자형태 파괴 현상은 적었지만 상대적으로 작은 크기의 구형의 마이크로입자가 더 많이 생성되 었다. 하지만, 산성조건에서 입자들 간의 강한 응집현상이 나타남에 따라 낱개의 분리되어 있는 단일입자 를 얻기 위해서는 초음파 등의 후처리 과정이 필요하였다.
        4,200원
        28.
        2008.09 구독 인증기관 무료, 개인회원 유료
        수평 배향 액정 모드는 양의 유전율 이방성과 음의 유전융 이방성 액정을 사용한 프린지 필드 스위칭과 양의 유전율 이방성 액정을 사용한 인플래인 스위칭 모드가 대표적이다 . 이 대표적인 세 구동 방식의 화질 특성을 비교하기 위하여 각각의 최척화된 위상지연 값 조건하에서 밝기, 명암대비율과 색 특성을 조사하였다. 그 결과 양액정과 음액정을 사용한 프린지 필드 스위칭 모드가 밝기와 명암대비율 면에 있어서 인플래인 스위칭 모드보다 우수한 특성을 보인다. 또한 양액정을 사용한 프린지 필드 스위 칭 모드는 시야각 방향에서 적은 색 변이 특성을 보인다.
        4,000원
        29.
        2007.12 구독 인증기관 무료, 개인회원 유료
        Field sequential 액정 디스플레이(FSLCD)는 컬러필터를 사용하지 않아 높은 투과율 특성을 보이고 광 원으로 LED를 사용함으로써 색재현성이 매우 우수하다. 하지만 FSLCD(60Hz 구동)를 실현하기 위해서는 액정의 응답속도가 5ms이하로 고속응답 특성을 보여야 한다. 따라서 본 논문에서는 고속응답 ECB(electrically controlled birefringence) 셀의 최적 구조를 연구하여 5ms 이하의 응답시간을 얻었다. 그리고 ECB 모드에서 높은 구동전압과 시야각을 개선하기 위해 필름 보상을 연구하였다. 판상형 액정필름(discotic film)과 TAC(triacetyl cellulose) 필름의 위상차 값을 최적화함으로써 구동전압을 5V로 낮추고 상하좌우에서 160° 이상(CR>10:1)의 시야각을 실현하였다.
        4,000원
        30.
        2003.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        4,000원
        31.
        1989.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A strain of Saccharomyces cerevisiae BY-366was found to produce a strong sucrose-hydrolyzing enzyme Using this strain, the optimal culture conditions for the production of invertase were investigated. The results are as follows : 1. For enzyme production, optimal temperature, initial pH and critical concentrations of sucrose and raffinose were 30℃, 5.0 and 3.0%, respectively. 2. Enzyme production was reached maxium by organic nitrogen source, 0.3% yeast extract plus 0.5% bactopeptone. 3. It was appeared the presence of 0.1M Mn^2+ and Fe^2+ ion was essential factors, on the other hand, 0.1M Ag^+ and Hg^2+ ion almost block in yeast growth and enzyme production. 4. Invertase productivity was reached maxium within 3days on stationary culture with medium-composed of sucrose 3%, bactopeptone 0.5%, yeast extract 0.3%, K_2HPO_4 0.1%, MgSO4·7H_2O 0.05%.
        4,000원
        32.
        2018.10 서비스 종료(열람 제한)
        Background : Recently, there has been an increase in the use of herbal drugs for healthcare. The reference standards of herbal medicine is used to quality control for herbal medicines. It have been produced and re-evaluated by Ministry of Food and Drug Safety, starting from 2002. In this study, we re-tested the quality of a variety of Herbal Reference Standards (HRS). We analyze the HRSs with identification test by High Performance Thin Layer Chromatography (HPTLC). All test is based on experimental method of the Korean Pharmacopoeia, the Korea Herbal Pharmacopoeia. Methods and Results : To check the stability of reference standards of herbal medicine, we annually performe real-time monitoring under storage condition (4℃). The aim of this study is to perform a stability testing for 200 national reference standards to ensure the reliability of standards. For example, there are reference standards of Osterici Radix, Polygoni Multiflori Radix, Lithospermi Radix etc. It was achieved by comparing the colors and Rf values of the bands in TLC with those of the marker compounds using High Performance Thin Layer Chromatography (HPTLC). Tests for each item are based on experimental methods of the official compendium or the previous study on establishment of HRSs. Through re-test system, we confirm stability and reliability of HRSs condition. Also, based on the results, these HRSs will be continuously supplied as Herbal Reference Standards of MFDS. Conclusion : As the result, the HPTLC results showed the same TLC patterns as compared with previous reports. Based on the all results that we will update the each certificate of analysis. We want to contribute for quality control of herbal medicines.
        33.
        2018.10 서비스 종료(열람 제한)
        Background : The reference standards of herbal medicine is used to quality control for herbal medicines. It is important that National Reference Standards maintain high stability of herbal medicines during all periods from the manufacture to the storage. In order to control quality of herbal medicines, the control reference standards (CRSs) have been produced by Ministry of Food and Drug Safety, starting from 2002. The designated CRSs are essential tests and assays to be carried out in accordance with the official compendium such as the Korean Pharmacopoeia and the Korean Herbal Pharmacopoeia. Methods and Results : The aim of this study is to perform a stability testing for 80 national reference standards to ensure the reliability of standards. For example, there are reference standards of Sweroside, Liquiritin, Wogonin etc. First of all, We randomly select three samples of CRSs and weight them and mobile phase is made suitable for the experimental conditions. We analyzed the purity value of each CRSs in calculating absolute peak area percent, using High Performance Liquid Chromatography (HPLC) based on the method in the official compendium. And the result showed that 80 evaluted CRSs were revealed more than 95% purity value. The stability of the CRSs under storage condition (4℃) were tested annually for 3 randomly selected samples. Conclusion : There are no significant difference among observed contents. The results of stability assessment represent suitable for quantitative analysis: less than 5% uncertainty of measurement. Even though this statistical analysis identified that stability was maintained for most of the products, some of them still need to be continuously monitored.
        34.
        2015.08 KCI 등재 서비스 종료(열람 제한)
        The object of this study was to obtain single oral dose toxicity of Arisaema Rhizome (Arisaema amurense f. serratum (Nakai) Kitag) aqueous extracts. Arisaema Rhizome (Chunnamsong in Korean) is one of the most important folk remedy plants used in Asia. In the study, a 28-day rat oral gavage study has been conducted with the extracts from Arisaema Rhizome at dose of 1,250, 2,500 and 5,000 ㎎/㎏/day. The following endpoints were evaluated: clinical observations, body weight, gross and microscopic pathology, clinical chemistry, and hematology. Based on the analysis of these endpoints, it was estimated that NOEL (no observed effect level) for male rats and NOAEL (no observed adverse effect level) for female rats are 5000 ㎎/㎏/day of the water-extracts from Arisaema Rhizome.
        35.
        2013.12 KCI 등재 서비스 종료(열람 제한)
        Pharmacological studies and clinical practices have indicated that Radix Astragali, a dried root of Astragalusmembranaceus possesses a lot of biological activities, including antioxidant, hepatoprotective, anti-diabetic, tonic, diuretic,antimicrobial, antiviral, and immunological activities. These biological activities approved by the modern pharmacologicalstudies are mainly due to the constituents of Astragalus membranaceus including polysaccharides, saponins, flavonoids,amino acids, and trace elements. In resent, the main constituents in the root part showing a lot of biological activities hasbeen isolated also from the aboveground parts such as leaves and sprouts in our laboratory. However, the safety evaluationfor the aboveground parts of Astragalus membranaceus should be checked before expanding their application as one of food.In the study, a 90-day rat oral gavage study has been conducted with the extracts from Astragalus membranaceus-above-ground parts at doses of 1000, 3000, and 5000㎎/㎏/day. The following endpoints were evaluated: clinical observations, bodyweight, gross and microscopic pathology, clinical chemistry, and hematology. Based on the analysis of these endpoints, it wasestimated that NOEL (no observed effect level) for male rats and NOAEL (no observed adverse effect level) for female ratsare 5000㎎/㎏/day of the water-extracts from Astragalus membranaceus-aboveground parts.
        38.
        2008.06 서비스 종료(열람 제한)
        식물의 유전자원은 여러 가지 형태로 보존되지만 자생식물의 화색은 꽃식물로서 자원을 활용하기 위한 측면에서도 큰 가치가 있다고 본다. 따라서 본 연구는 우리나라 자생식물의 화색을 anthocyanidin 분석에 의해 좀 더 진보된 유전자원으로서의 역할을 증진시키기 위해 1차적으로 문헌을 통한 자생식물의 계절별 화색을 알아보아 기초자료로 활용하고자 실시하였다. 자생식물은 총 107종을 선발하여 분류하였으며(Table 1), 한국 자원식물명총람, 한국의 야생식물, 야생화쉽게찾기 등의 자료를 참고하였다. 국내에는 관상가치가 높아 화훼작물로 개발 가능한 자생식물이 많이 있으나 화색에 관한 연구는 극히 미흡한 실정이다. 따라서 앞으로 화색 육종이나 유전자원으로서의 가치 보존을 위해서 폭 넓은 자생식물의 화색에 관한 연구를 수행할 예정이며, 화색육종을 위한 안토시아니딘에 대한 분석을 병행하고자 한다.
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