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        검색결과 38

        22.
        2007.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
          A space launch vehicle system represents a typical example of large-scale multi-disciplinary systems, consisting of subsystems such as mechanical structure, electronics, control, telecommunication, propulsion, material engineering etc. A lot of cost is
        4,000원
        24.
        1995.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        전국 8개 지역별 각 사과원에서 채집된 점박이응애(Tetranychus urticae Koch)에 대한 저항성 정도를 일본 감수성 계통과 비교한 결과 지역별 현저한 감수성 차이를 보였다. Azocyclotin, fenpropathrin, propargite 및 abamectin에 대해서는 낮거나 중간 정도의 저항성을, dicofol, fenpyroximate 및 pyridaben에 대해서는 높은 저항성을 나타내었다. 이들 계통은 한종 또는 두종 이상의 약제에 대해 감수성을 보여 특정 지역에 대해서는 적당한 살비제의 선택적 이용으로 점박이응애를 효과적으로 방제할 수 있을 것으로 사료된다.
        4,000원
        25.
        2018.11 KCI 등재 서비스 종료(열람 제한)
        본 연구에서는 하천 제방에 대한 홍수취약성을 평가하는 새로운 기법을 제시하고 기후변화에 따라 변화하는 수위에 대하여 제방에 미치는 영향을 분석하였다. 이를 위해 먼저 2차원 지하수침투 모형인 SEEP/W를 이용하여 제방의 침투거동을 분석하여 침투안전성을 평가하였다. 침투거동뿐만 아니라 기후변화에 따른 하천환경여건을 고려하는 제방의 취약성 분석 기술이 필요함으로써 본 연구에서는 추가적으로 제방의 취약성 분석에 필요한 인자를 도출하여 제방의 홍수취약성지수(levee flood vulnerability index; LFVI)에 의한 취약성 평가기법을 새로이 개발 하였다. 대상지역을 한강 본류 서울 구간으로 선정하여 하도별 제방의 크기를 조사하였고 조사한 제방을 상류부, 중류부, 하류부로 구분하여 3개의 대표 제방을 선정하였다. 이들 대표 제방지점에서 현재의 계획홍수위와 기후변화 시나리오 RCP8.5를 고려한 계획홍수위를 적용하여 제방의 활동 안전율과 제방 홍수취약성지수를 분석하였다. 그리고 제방홍수취약성지수를 구성하는 각각 인자들에 대하여 기후변화에 따른 변화 정도를 파악하였다. 이들 인자들을 종합적으로 활용한 제방홍수취약성지수 값을 이용하여 최종적으로 기후변화에 따른 제방의 취약성을 추정할 수 있도록 하였다.
        26.
        2016.10 서비스 종료(열람 제한)
        Background : Acanthopanax sessiliflorus (Rupr. et Maxim) Seem, belonging to the Araliaceae family, is widely distributed in Korea, China, and Japan. The plants belonging to Acanthopanax species are traditionally used in Korea as anti-rheumatoid arthritis, anti-inflammatory and anti-diabetic drugs and are recognized to have ginseng-like activities. A simple and sensitive high-performance liquid chromatographic (HPLC) method was developed and validated for independent analysis of major compounds and chlorogenic acid in A. sessiliflorus fruits. Chlorogenic acid was reported that prevent cancer and cardiovascular disease in vivo. Also, it has antioxidant effect in vitro test. In the previous experiment, chlorogenic acid were found in A. sessiliflorus fruits. This study was performed to identification of the major compounds and investigate the method validation for the determination of chlorogenic acid in A. sessiliflorus fruits. Methods and Results : Three major compounds were recorded on a Varian Unity Inova AS-400 FT-NMR spectrometer and analyzed by the new HPLC analysis method. HPLC analysis was carried out using an Waters e2695 and PDA detector. The new analyasis method was validated by the measurement of intra-day, inter-day precision, accuracy, limit of detection (LOD, S/N=3), and limit of quantification (LOQ, S/N=10) of chlorogenic acid. The results showed that the correlation coefficient (R2) for the calibration curves of chlorogenic acid was 0.997 in terms of linearity. The limit of detection (LOD) and limit of quantification (LOQ) were 0.565 ㎍/ml and 2.88 ㎍/ml, respectively. There was no interfering peak observed each other and HPLC system was suitable for analysis showing goodness of peak and high precision. Conclusion : This method is suitable to detect and quantify major compounds in A. sessiliflorus fruits. Furthermore, the result will be applied to establish chlorogenic acid as an standard compound for A. sessiliflorus fruits.
        27.
        2016.06 KCI 등재 서비스 종료(열람 제한)
        This study was carried out to develop an effective seed propagation method for Thalictrum rochebrunianum var. grandisepalum (H. Lev.) Nakai by analyzing seed dormancy types and germination characteristics. Seeds were collected between September to October at Gangwon province, and well-selected seeds were used while being dry-stored at 4±1℃. The seed size ranged 4.52 × 1.58 ㎜ and the weight of thousand seeds were 1,603.5 ± 0.02 ㎎. The moisture content was 7.2%. Seeds were achene type, and morphology characters showed an elliptical shape and rough texture, and light brown in color. Moist-chilling treatment was conducted for dormancy breaking because the seeds had an undeveloped embryo of liner type. The embryo had developed during a moist-chilling period, constantly, and fully developed in 10 weeks. Consequently, it seemed to be non-deep complex or intermediate complex type of morphophysiological dormancy, and embryo dormancy was broken by wet-chilling for 10 weeks. After 10 weeks of wet-chilling treatment, seed germination began. Germination percentage was higher in dark condition raher than light condition and recorded the maximum at 25℃ in the dark (16.3%). A pre-soaking treatment with a combined plant growth hormones promoted germination and shortened T50. Specifically, seed germination of 84.5% was achieved by pre-soaking of seeds with a combined solution of 500 ㎎/L GA3 and 10 ㎎/L kinetin for 24 h after a wet-chilling treatment for 10 weeks. Thus the effect of plant growth hormones coupled with chilling temperature on seed breaking dormancy provide asubsequent growth of seedlings for successful plantation.
        28.
        2013.09 KCI 등재 서비스 종료(열람 제한)
        Olive flounder (Paralichthys olivaceus) is one of the commercial important flatfish species in Korea. The ocular signal transduction pathway is important in newly hatched flounders because it is closely involved in the initial feeding phase thus essential for survival during the juvenile period. However, the study of gene expression during ocular development is incomplete in olive flounder. Therefore we examined the expression analysis of specifically induced genes during the development of the visual system in newly hatched flounders. We searched ocular development-involved gene in the database of expressed sequence tags (ESTs) from olive flounder eye and this gene similar to arrestin with a partial sequence homology. Microscopic observation of retinal formation corresponded with the time of expression of the arrestin gene in the developmental stage. These results suggest that arrestin plays a vital role in the visual signal transduction pathway of the retina during ocular development. The expression of arrestin was strong in the ocular system during the entirety of the development stages. Our findings regarding arrestin have important implications with respect to its biological role and evolution of G-protein coupled receptor (GPCR) signaling in olive flounder. Further studies are required on the GPCR-mediated signaling pathway and to decipher the functional role of arrestin.
        29.
        2013.09 KCI 등재 서비스 종료(열람 제한)
        Cathepsins are members of the multigene family of lysosomal cysteine proteinases and have regulated function in several life processes. The potential role of cathepsin F cysteine gene was expected as protease in the yolk processing mechanism during early developmental stage, but expression analysis was unknown after fertilization. The alignment analysis showed that amino acid sequence of cathepsin F from olive flounder liver expressed sequence tag (EST) homologous to cathepsin F of other known cathepsin F sequences with 87-98% identity. In this study, we examined the gene expression analysis of cathepsin F in various tissues at variety age flounder. Tissue distribution of the cathepsin F mRNA has been shown to be ubiquitous and constitutive pattern regardless of age in each group, although derived from cDNA library using liver sample. The mRNA level of cathepsin F more increased as developmental proceed during embryogenesis and early developmental stage, especially increased in the blastula, hatching stage and 3 days post hatching (dph). As a result, it may suggest that the proteolysis of yolk proteins (YPs) has been implicated as a mechanism for nutrient supply during early larval stages in olive flounder.
        30.
        2013.03 서비스 종료(열람 제한)
        Acinetobacter baumannii is usually considered an opportunistic pathogen that it responsible for a variety of nosocomial infections, such as, pneumonia, tracheobronchitis, meningitis, endocarditis, peritonitis, skin and soft tissue infections, and urinary tract infections. However, over the years, the organism has developed substantial antimicrobial resistance, and thus, the management of infections has become more difficult. The less common infective endocarditis is one of the more serious consequences of nosocomial bacteremia. Here, we report the successful treatment of the first case of multidrug-resistant A. baumannii endocarditis in a 33-year-old patient.
        32.
        2011.07 KCI 등재 서비스 종료(열람 제한)
        The variation of groundwater level in Jeju Island is analyzed with the data of precipitation observed from 48 monitoring post and groundwater level observed from 84 monitoring wells during 2001 to 2009. The groundwater level rises in summer and falls in winter. The rise of groundwater level by precipitation is fast and small in the eastern region and slow and large in the western region. However, the speed of fall during the period of no rain is slower in the eastern region than in the western region. It tells that permeability is greater in the eastern region than in the western region. In this paper, we set up the base level of groundwater and calculate recharge volume between the base level and groundwater surface. During the period, the average recharge volume was 9.83 ×109㎥ and the maximum recharge volume was 2.667 ×1010㎥ after the typhoon Nari. With these volume and the recharge masses obtained by applying the recharge ratio of 46.1%, estimated by Jeju Province (2003), the porous ratio over the whole Jeju Island is 16.8% in average and 4.6% in the case of maximum recharge volume just after typhoon Nari. A large difference in the two ratios is because that it takes time for groundwater permeated through the ground just after rain fall to fill up the empty porous part. Although the porous ratios over the whole Jeju Island obtained in this way has a large error, they give us the advantage to roughly estimate the amount of recharged groundwater mass directly from observing the groundwater level.
        34.
        2007.12 KCI 등재 서비스 종료(열람 제한)
        The aim of this study was to isolate chicken feather-degrading bacteria with high keratinolytic activity and to investigate cultural conditions affecting keratinolytic enzyme production by a selected isolate. A chicken feather-degrading bacterial strain CH3 was isolated from poultry wastes. Isolate CH3 degraded whole chicken feather completely within 3 days. On the basis of phenotypical and 16S rDNA studies, isolate CH3 was identified as Bacillus thuringiensis CH3. This strain is the first B. thuringiensis described as a feather degrader. The bacterium grew with an optimum at pH 8.0 and 37℃, where maximum keratinolytic activity was also observed. The composition of optimal medium for keratinolytic enzyme production was feather 0.1%, sucrose 0.7%, casein 0.3%, K2HPO4 0.03%, KH2PO4 0.04%, MgCl2 0.01% and NaCl 0.05%, respectively. The keratinolytic enzyme had a pH and temperature optima 9.0 and 45℃, respectively. The keratinolytic activity was inhibited ethylenediaminetetraacetic acid, phenylmethylsulfonyl fluoride, and metal ions like Hg2+, Cu2+ and Zn2+. The enzyme activated by Fe2+, dithiothreitol and 2-mercaptoethanol.
        35.
        2007.11 KCI 등재 서비스 종료(열람 제한)
        The removal of nitrogen compounds from a wastewater is essential and it is often accomplished by biological process. An aerobic nitrate-removing bacterium was isolated from a municipal sewage treatment plant and soil. On the basis of its morphological, cultural and physiological characteristics and 16S rRNA sequencing data, this strain was identified as Pseudomonas fluorescens, and named as P. fluorescens K4. The optimal conditions of the initial pH and temperature of media for its growth were 7.0~8.0 and 30℃, respectively. P. fluorescens K4 was able to remove 99.9% of nitrate after 24 h in a culture. The strain could grow with a nitrate concentration up to 800 mg/l and was able to remove 99.9% of nitrate after 104 h of incubation. The optimal electron donor was sodium citrate for a nitrate removal. The strain K4 showed a capability of a complete nitrate removal when the initial C/N ratio was 1.0. An effect of the initial seed concentration was observed for a cell of 10% (v/v) for a nitrate removal. Especially P. fluorescens K4 could completely remove 200 mg/l ammonium for 3 days.
        37.
        2003.08 KCI 등재 서비스 종료(열람 제한)
        Regeneration ability of plant is very important for producing transgenic plants by genetic engineering. Fifty rice cultivars and lines were screened for their regeneration ability in vitro and an attempt was made to increase shoot regeneration by substitu
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