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        검색결과 122

        41.
        2011.12 구독 인증기관 무료, 개인회원 유료
        Pneumatosis cystoides intestinalis (PCI) is a rare condition characterized by multiple intramural pockets of gas filled cysts in the intestinal wall. PCI is usually found incidentally on an imaging study. Many different causes of PCI have been suggested, including mechanical, pulmonary, and bacterial causes. Treatment is usually conservative, including oxygen and antibiotic therapy. We report on two cases of PCI, without symptoms, in a 62-year-old male and a 72-year-old male. Computed tomography showed numerous, small, round, and air densities on the sigmoid colon. Colonoscopy showed numerous, variable-sized, sessile polypoid, balloon-like distended, and protruding subepithelial masses covered with normal colonic mucosa on the sigmoid colon. We observed that when the cyst was stuck with a needle, the size of the cyst was reduced and showed a flat termination. Therefore, we made a diagnosis of PCI and report on the case with references.
        4,000원
        43.
        2009.10 구독 인증기관·개인회원 무료
        This study aimed to evaluate the antioxidant activity of chestnut honey which were harvested at various areas in South Korea. First at all, we measured the total phenols content through a spectrophotometric determination with a modified Folin-Ciocalteu method and total flavonoids content determined with aluminium chloride. Total phenolic compounds was highest in Sunchang of Chestnut honey(2.21mg/ml)and flavonoids contents was also the highest in Sunchang of Chestnut honey(1.02mg/ml) than other samples. For measured the antioxidant activity of chestnut honey, we performed DPPH(2,2-diphenyl-1-picrylhydrazyl) test and FRAP(ferric reducing-antioxidant assay)test. DPPH scavenging activity highest in Sunchang of Chestnut honey more than 50% DPPH scavenging activitywhile other samples (Gong-ju, Yechen, Chung-ju, Imsil, Ha-dong) showed more than 25% DPPH scavenging activity. The ferric reducing-antioxidant assay (FRAP) is based on the reduction of ferric 2,4,6-tris(2-pyridyl)-1,3,5-triazine [Fe(III)-TPTZ] by spectrophotometric analysis. Sunchang were found to have more than 532μM FRAP activity while other samples (Gong-ju, Yechen, Chung-ju, Imsil, Ha-dong) showed more than 300μM FRAP activity. The results suggested that chestnut honey strong antioxidant activity and it could be utilized as a source of natural antioxidant.
        44.
        2009.10 구독 인증기관·개인회원 무료
        To identify DNA markers linked to a elytra polymorphism, amplified fragment length polymorphism (AFLP) analysis was performed on DNA samples from four each colour pattern individuals (2 females and males), for example, succinea 1, succinea 2, conspicua, and spectabilis. As a result of performing AFLP analysis with the restriction endonuclease combination EcoRⅠ and Mse I, total of 2,269 AFLP fragments which were specific to succinea, conspicua and spectabilis was identified using 24 different AFLP primer combinations. Among these 2,269 fragments, 16 bands which were the most specific to one color patterns were isolated, cloned and sequenced. Subsequent UPGMA cluster analysis revealed that population of H. axyridis was divided four major group and these genetic tree showed that H. axyridis elytra colour diversity was affected by genetic polymorphism. It is considered that these genetic analyses may be facilitated the understanding of molecular genetic mechanism related with the wing colour pattern formation in this species.
        46.
        2008.10 구독 인증기관·개인회원 무료
        As indigenous aphid parasitoid, Aphelinus varipes kill aphids for feeding in addition to parasitization. Because of this characteristic of A. varipes, this parasitoid may have the possibility of biological control agent against aphids. So we have evaluated traits such as daily paratization, total parasization, number of aphids killed by host feeding, sex ratio, development time, pupal mortality of A. varipes parasitizing green peach aphid, Myzus persicae. At 25°C and 16L:8D, longevity, total paratization and host feeding of A. varipes female was 11.0, 25.3, and 63.3 days, respectively. And development time of male and female, sex ratio (M:F), pupa mortality of offspring of A. varipes were 12.0 days, 12.5 days, 0.88, and 11.6%, respectively. However, because these results are not enough to estimate potential of A. varipes as biological control agents/factors, other factors such as host suitability (Macrosiphum euphorbiae, Aulacorthum solani), effect of temperature, and host seeking behavior of A. varipes continually will be investigated.
        47.
        2008.10 구독 인증기관·개인회원 무료
        As an effective generalist predator of aphids and other hemipteran pests, Harmonia axyridis has been a successful biological control agent. Interestingly, it was known that there were varied in color patterns on H. axyridis elytra. In fact, Seo & Youn (2007) reported that H. axyridis had five color patterns, for example, succinea 1, 2, conspicua, spectabilis, and axyridis. But there are uncertain that H. axyridis elytra colour patterns are regulated by genetic polymorphism. So we tried to what is the reason that color patterns are greatly variable. To identify DNA markers linked to a elytra polymorphism, amplified fragment length polymorphism (AFLP) analysis was performed on DNA samples from four female succinea, conspicua, spectabilis and Coccinella septempunctata which is another species in Coccinellidae. AFLP analysis with the restriction endonuclease combination EcoRⅠ and MseⅠwas performed. Using 12 AFLP primer pairs, nine AFLP fragments which is specific between succinea, conspicua, spectabilis was identified. These nine AFLP fragments were isolated, cloned and sequenced. Subsequent UPGMA cluster analysis revealed three major group of H. axyridis populations. These genetic tree showed that H. axyridis elytra colour diversity was affected by genetic polymorphism. For more genetically understanding elytra colour genes, different primer combinations may be need to be generate enough polymorphic markers. These genetic analyses may be facilitate the understanding of molecular mechanism behind wing colour pattern formation.
        52.
        2016.06 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        Inactive space objects are usually rotating and tumbling as a result of internal or external forces. KOREASAT 1 has been inactive since 2005, and its drift trajectory has been monitored with the optical wide-field patrol network (OWL-Net). However, a quantitative analysis of KOREASAT 1 in regard to the attitude evolution has never been performed. Here, two optical tracking systems were used to acquire raw measurements to analyze the rotation period of two inactive satellites. During the optical campaign in 2013, KOREASAT 1 was observed by a 0.6 m class optical telescope operated by the Korea Astronomy and Space Science Institute (KASI). The rotation period of KOREASAT 1 was analyzed with the light curves from the photometry results. The rotation periods of the low Earth orbit (LEO) satellite ASTRO-H after break-up were detected by OWL-Net on April 7, 2016. We analyzed the magnitude variation of each satellite by differential photometry and made comparisons with the star catalog. The illumination effect caused by the phase angle between the Sun and the target satellite was corrected with the system tool kit (STK) and two line element (TLE) technique. Finally, we determined the rotation period of two inactive satellites on LEO and geostationary Earth orbit (GEO) with light curves from the photometry. The main rotation periods were determined to be 5.2 sec for ASTRO-H and 74 sec for KOREASAT 1.
        53.
        2015.12 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        Several optical monitoring strategies by a ground-based telescope to protect a Geostationary Earth Orbit (GEO) satellite from collisions with close approaching objects were investigated. Geostationary Transfer Orbit (GTO) objects, Inclined GeoSynchronous Orbit (IGSO) objects, and drifted GEO objects forced by natural perturbations are hazardous to operational GEO satellites regarding issues related to close approaches. The status of these objects was analyzed on the basis of their orbital characteristics in Two-Line Element (TLE) data from the Joint Space Operation Center (JSpOC). We confirmed the conjunction probability with all catalogued objects for the domestic operational GEO satellite, Communication, Ocean and Meteorological Satellite (COMS) using the Conjunction Analysis Tools by Analytical Graphics, Inc (AGI). The longitudinal drift rates of GeoSynchronous Orbit (GSO) objects were calculated, with an analytic method and they were confirmed using the Systems Tool Kit by AGI. The required monitoring area was determined from the expected drift duration and inclination of the simulated target. The optical monitoring strategy for the target area was analyzed through the orbit determination accuracy. For this purpose, the close approach of Russian satellite Raduga 1-7 to Korean COMS in 2011 was selected.
        54.
        2015.07 서비스 종료(열람 제한)
        Zinc finger nucleases (ZFNs) have been used for targeted mutagenesis in eukaryotic cells. Custom-designed ZFNs can induce double-strand breaks (DSBs) at a specific locus. Our custom ZFN dimer was designed 3-finger of left and 4-finger of right with 2 kb size using 2A. A Ti-plasmid vector, pTA7002 containing the target site of SSS4A gene for a ZFN pair, that was shown to be active in yeast, was integrated in the rice genome. This promising technique for genome engineering was induced into 4 exon region of SSS4A gene in rice genome using Agrobacterium-mediated transformation. The SSS4A full-length cDNA was 5,070 bp consisting of a 318 bp 5′-untranslated region (UTR), a complete ORF of 2,928 bp encoding a polypeptide of 975 amino acids and a 3′-UTR of 1,824 bp. The vector is based on glucocorticoid receptor inducible gene expression system. Thus, SSS4A::ZFN expression was tightly controlled and the phenotype in low concentrations 10uM of the glucocorticoid hormone dexamethasone (DEX). In plant cells, transient ZFN expression is achieved by direct gene transfer into the target cells. For an alternative, ZFN delivery and production of mutant plants using a tobacco transient expression system for indirect transient delivery of ZFNs into a variety of tissues and cells of plants. ZFN activity was determined by PCR and sequence analysis of the target site. ZFN induced plants were obtained in up to 2% of the PCR products, consisting of deletions ranging between 1and 100 bp and insertions ranging between 1 and 10 bp. Our results describe an alternative to direct gene transfer for ZFN delivery and for the production of mutated rice.
        55.
        2013.07 서비스 종료(열람 제한)
        Genetically modified (GM) plant claims to be the solution to global poverty, and potentially solving environmental change and food requirement by increased human population. In this study, we were evaluating agronomic characteristics and chemical properties of two GM drought-tolerant rice (CaMsrB2-8 and CaMsrB2-23) compared with donor cultivars (Ilmi). Statistical analysis agronomic characteristics GM and donor rice showed no significant difference between both of them. Yield and appearance of rice grain, GM rice was a similar to the donor rice. Chemical composition analysis showed that GM drought-tolerant rice has no different with donor rice. This result indicated that GM drought tolerant rice has no big significant difference agronomic character and chemical properties; it can be solve food shortages in spite of drought condition.
        56.
        2012.07 서비스 종료(열람 제한)
        Rye has important genes for biotic and abiotic stress resistance. Introduction of these genes to wheat by breeding wheat-rye translocation have been intensively used in wheat breeding program. Rye chromatin 1RS and/or 2RL show superior performance in unfavorable environments. In order to develop high yielding wheat, we applied various molecular breeding strategies. To develop EST-derived 1RS specific markers, we used comparative genomics with public sequence databases of Poaceae family. Putative rye chromatin specific sequences were used to design 1RS specific markers. To identify genes related to water deficiency, cDNA AFLP analysis was used in PEG treated seedlings of 1RS RILs. For functional analysis of identified genes and markers, we used Brachypodium distachyon, as a new model plant of temperate grasses. B. distachyon were recently applied for transformation and we constructed Agrobacterium-mediated transformation system. Integration of those strategies and conventional breeding method would enhance the usefulness of rye chromatins for wheat improvement.
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