검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 53

        41.
        2014.02 서비스 종료(열람 제한)
        Weir is installed across a river with the general purpose of controlling water level and water intake. Most weirs installed on rivers are fixed weirs and hinder water flow to bring about sedimentation of earth and sand and deterioration of water quality causing destruction of the river environment. Due to such reason, movable weir which can control reservoir capacity has been developed recently and increasingly installed instead of existing fixed weir and various studies have been carried out to develop methods for self-purification effect and reducing sedimentation of earth and sand.<br>From movable weir, rubber dams have been used in many construction sites due to ease of maintenance administration but if the rubber sheet is damaged artificially or by natural disaster, harm is done to the river and high maintenance and repair costs are incurred if neglected for a long time. Also, the life expectancy of a rubber dam is over 30 years so appropriate management and maintenance administration are required to secure safety of the river and proper water procurement.<br>This study developed rubber sheet for improvement of maintenance and repair for rubber dam which is repaired most often for purpose of irrigation and water intake in rivers and such results are as follows.<br>As a result of investigating repair cases when operating rubber dams, repair cases for poor assembly of rubber panel was only about 3.5% of all cases while there were no reported cases of self-defect of rubber dams. From a total of 19 cases of rubber dam repairs, 12 cases (63.2%) were due to external conditions so it is determined that rubber sheet development is needed for improving the durability and safety of rubber dams. Regarding such finding, this study developed a rubber dam enabling bullet resistance/cut resistance by adding aramid sheet when producing rubber sheet and enabled abrasion check by coating the outer layer with colored synthetic rubber.<br>As a result of developing rubber sheet for improving maintenance and repair of rubber dams, durability and safety were found to be better than existing rubber dam while there were effects of ease of maintenance administration and greater economic efficiency as well. For continuous and permanent use of rubber dams, it is determined that systematic research and continuous development are necessary.
        42.
        2012.07 서비스 종료(열람 제한)
        Cereal seeds, sorghum, foxtail millet, hog millet, adlay, and corn are traditionally used as health assistant as well as energy supplying food in Korea. While beneficial phytochemicals to human have revealed in cereals, the information on peptides from cereals is far less accumulated than major reserve protein. Here, we analyzed peptide profiles using surface enhanced laser desorption/ionization time of flight mass spectrometry (SELDI-TOF MS) in cereal seeds for construction of peptide information and attempted to develop peptide biomarkers for cereal identification. To optimize the analysis condition of SELDI-TOF MS, the effect of dilution factor on binding affinity to protein chips was tested using CM10 and Q10 arrays. Peptide clusters were significantly different at the level of 0.01 p-value. Peak spectra were the most stable in 1:50 of dilution factor in both chip arrays. Numbers of detected peak of 5 cereal seeds were 131 in CM10 and 74 in Q10 array. Each cereal was grouped as a cluster and well discriminated into different cluster in the level of 0.01 p-value. Numbers of potentially identified peptide biomarkers are 11, 13, 9, 5 and 12 in sorghum, foxtail millet, hog millet, adlay and corn, respectively. This study demonstrates that each cereal seed have own distinguishable specific peptides although their function are not identified yet in this study. In addition, the proteomic profiling using SELDI-TOF MS techniques could be a useful and powerful tool to discover peptide biomarker for discrimination and assess crop species, especially under 20 kDa.
        43.
        2012.06 KCI 등재 서비스 종료(열람 제한)
        광나무(L. lucidum)는 ursolic acid와 oleanolic acid를 다량 포함하고 있다. 본 연구에서는 광나무 열매, 줄기, 잎 세 부위 추출물의 항주름 효능을 평가하였다. 광나무 추출물은 human skin fibroblasts에서 독성이 없을 뿐만 아니라 MMP-1과 MMP-2의 발현을 감소시키고 COL1A1의 발현을 증가시켰다. 이들 추출물은 모두 농도 의존적으로 COL1A1의 발현을 증가시켰으며 MMP-1과 MMP-2의 발현을 감소시켰다. 광나무 세 부위 추출물 가운데, 열매 부위에 가장 많은 양의 ursolic acid 와 oleanolic acid가 함유되어 있었으며 가장 강한 COL1A1 upregulating 효과와 MMP-1과 MMP-2 downregulating 효과를 나타냈다. 이처럼 항주름 효능을 보이는 광나무 열매 추출물은 기능성 화장품 소재로 개발될 수 있는 가능성이 있다.
        45.
        2011.09 서비스 종료(열람 제한)
        The reproductive life-history of molluscs can be divided into gonochorism and hermaphroditism, while hermaphroditism is further classified into simultaneous (synchronous or functional) and sequential (asynchronous) (Heller 1993 Gosling 2004). Approximately 40% of the 5600 mollusc genera are either simultaneous or sequential hermaphrodites. Hermaphroditism occurs in 100% of the Solenogastres, 99% of the Opisthobranchia, 100% of the Pulmonata, 3% of the Prosobranchia and 9% of the Bivalvia. Simultaneous hermaphroditism is the simultaneous release of eggs and sperm by one organism during the same season. Sequential hermaphroditism is the function of an organism first as one sex, then as another (Heller 1993). This study investigated the sex of Manila clam, Ruditapes philippinarum by verifying changes in sex ratio (F:M) with size and sex reversal stages. Adult one-year-old (11 months; SL 36.75±3.0 mm) R. philippinarum were used for sex reversal identification. Each individual was tagged on its shell prior to being reared in the wild for reproductive analysis, and sex was confirmed using the germ cell aspiration (GCA) method. Sex ratio (F:M) at the commencement of the study (June 2009) was 1:1.23, but changed to 1:0.87 by the end (July 2010). Overall sex reversal rate was 19.0%. Specifically, male to female sex reversal ratio was 21.05%, which was higher than the female to male sex reversal ratio of 12.9%. Based on our results, R. philippinarum has been confirmed to possess a sequentially hermaphroditic life-history.
        52.
        2007.06 KCI 등재 서비스 종료(열람 제한)
        Nitrogen (N) fertilization is essential for alleviating nutrient deficiencies of the world’s population by increasing rice production, one of the most important food crops of our time. Here we established an in vivo hydroponics rice seedling culture system to investigate the physio-biochemical and molecular responses of various rice genotypes to low nitrogen application. Yoshida’s nutrient solution (YS) was used to grow rice seedlings, and at three-week-old the seedlings manifested highly stable and reproducible symptoms, such as reduced shoot growth and length. Out of 12 genetically selected or tested genotypes, almost all (11 genotypes) showed varied degrees of growth reduction response to applied nitrogen (4 and 40 ppm N for treatment and control, respectively), but SR19663-B-B-34-3-3-3-1 showed similar growth as the control though its leaf width was smaller than the control. The leaves of a 11 representative low nitrogen-responsive genotype as BG90-2 were sampled for revealing the protein profiles between low and normal (control) nitrogen application by using two-dimensional gel electrophoresis (2-DGE) followed by staining of separated proteins with silver. Fifty differentially expressed silver stained protein spots were excised from 2-D gels and 41 proteins identified using high-throughput mass spectrometry (MS) using matrix-assisted laser desorption/ionization-time of flight-MS and nano electrospray ionization liquid chromatography tandem MS. These proteins could be assigned as major (energy metabolism, photosynthesis and oxidative stress) and minor functional categories, revealing many novel low N-responsive proteins, including those having energy/photosynthesis, and defense/stress, and iron homeostasis-related functions.
        1 2 3