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        검색결과 17

        1.
        2021.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Large earthquakes with (MW > ~ 6) result in ground shaking, surface ruptures, and permanent deformation with displacement. The earthquakes would damage important facilities and infrastructure such as large industrial establishments, nuclear power plants, and waste disposal sites. In particular, earthquake ruptures associated with large earthquakes can affect geological and engineered barriers such as deep geological repositories that are used for storing hazardous radioactive wastes. Earthquake-driven faults and surface ruptures exhibit various fault zone structural characteristics such as direction of earthquake propagation and rupture and asymmetric displacement patterns. Therefore, estimating the respect distances and hazardous areas has been challenging. We propose that considering multiple parameters, such as fault types, distribution, scale, activity, linkage patterns, damage zones, and respect distances, enable accurate identification of the sites for deep geological repositories and important facilities. This information would enable earthquake hazard assessment and lower earthquakeresulted hazards in potential earthquake-prone areas.
        4,600원
        2.
        2018.03 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        Salvia miltiorrhiza (Danshen) is perennial plant and commonly used in traditional Chinese medicine to treat numerous diseases like cardiovascular and cerebrovascular diseases, coronary heart disease, myocardial infarction, stroke and some viral diseases. Nevertheless, no study has been conducted on the antiviral properties of crude extract of Salvia miltiorrhiza against Influenza virus. In an attempt to identify new potential anti-influenza virus agents, 200 natural oriental herbal medicines were screened and we found that Salvia miltiorrhiza has a potential anti-influenza effect. Therefore, in this study, we investigated the protective effect of aqueous extract from Salvia miltiorrhiza against divergent influenza A subtypes using murine model of influenza A infection. Effective dose of aqueous extracts of Salvia miltiorrhiza in BALB/c mice displayed higher survival rate and lower lung viral titers when challenged with lethal doses of influenza A subtypes ({A/Aquatic bird/Korea/ W81/2005(H5N2)}, {A/PR/8/34(H1N1)}, {A/Aquatic bird/Korea/W44/2005(H7N3)} and {A/Chicken/ Korea/116/2004(H9N2)}). In vivo results exhibited that Salvia miltiorrhiza induced prophylactic effect in BALB/c mice against Influenza virus by disrupting viral replication or preventing viral infection by creating an antiviral state in the lungs. Taken together, the use of aqueous extracts of Salvia miltiorrhiza as an orally active antiviral agent, will be potential candidates for prophylactic treatments against Influenza A virus for humans and animals.
        4,000원
        4.
        2015.10 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Bi0.5Na0.5TiO3 (BNT) based ceramics are considered potential lead-free alternatives for Pb(Zr,Ti)O3(PZT) based ceramics in various applications such as sensors, actuators and transducers. However, BNT-based ceramics have lower electromechanical performance as compared with PZT based ceramics. Therefore, in this work, lead-free bulk 0.99[(Bi0.5Na0.5)0.935Ba0.065](1-x)LaxTiO3-0.01SrZO3 (BNBTLax-SZ, with x = 0, 0.01, 0.02) ceramics were synthesized by a conventional solid state reaction The crystal structure, dielectric response, degree of diffuseness and electric-field-induced strain properties were investigated as a function of different La concentrations. All samples were crystallized into a single phase perovskite structure. The temperature dependent dielectric response of La-modified BNBT-SZ ceramics showed lower dielectric response and improved field-induced strain response. The field induced strain increased from 0.17% for pure BNBT-SZ to 0.38 % for 1 mol.% La-modified BNBT-SZ ceramics at an applied electric field of 6 kV/mm. These results show that Lamodified BNBT-SZ ceramic system is expected to be a new candidate material for lead-free electronic devices.
        4,000원
        5.
        2005.06 구독 인증기관 무료, 개인회원 유료
        Cloned calves derived from somatic cell nuclear transfer (SCNT) have been frequently lost by sudden death at 1 to 3 month following healthy birth. To address whether placental anomalies are responsible for the sudden death of cloned calves, we compared protein patterns of 2 placentae derived from SCNT of Korean Native calves died suddenly at two months after birth and those of 2 normal placentae obtained from AI fetuses. Placental proteins were separated using 2-Dimensional gel electrophoresis. Approximately 800 spots were detected in placental 2-D gel stained with coomassie-blue. Then, image analysis of Malanie III (Swiss Institute for Bioinformatics) was performed to detect variations in protein spots between normal and SCNT placentae. In the comparison of normal and SCNT samples, 8 spots were identified to be up-regulated proteins and 24 spots to be down-regulated proteins in SCNT placentae, among which proteins were high mobility group protein HMG1, apolipoprotein A-1 precursor, bactenecin 1, tropomyosin beta chain, H+-transporting ATPase, carbonic anhydrase II, peroxiredoxin 2, tyrosine-rich acidic matrix protein, serum albumin precursor and cathepsin D. These results suggested that the sudden death of cloned calves might be related to abnormal protein expression in placenta.
        4,000원
        7.
        1983.12 구독 인증기관·개인회원 무료
        9.
        2020.09 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        The human and capital resources from foreign investors are important sources of finance for developing countries. Foreign ownership can help the firm to raise funds for operations and the foreign management can help the firm expand the market and improve management. However, does this really happen to Vietnamese firm? To find the answer to that question, this paper examines the impact of foreign ownership and management on the financial performance of listed firms on Vietnam’s stock market. The data collected include 427 listed firms in all fields over five years, from 2014 to 2018. The financial performance is measured by Tobin’s Q, ROA and ROE. The study carried out testing of each model by the least squares method of Pool OLS, assessing random effects (REM) and evaluating fixed effects (FEM). The most effective model is the FEM model. The results show that the foreign ownership ratio and the size of the firm have a positive impact on the financial performance. The foreign management, the age of the firms, the liquidity and financial leverage have a negative impact on the financial performance. Based on the research results, the study proposes some recommendations to improve the financial performance of listed firms in Vietnam.
        10.
        2016.05 서비스 종료(열람 제한)
        Background : Water uptake and flow across cellular membranes is a fundamental requirement for plant growth and development, and plant water status is important not only for plant growth under favorable conditions but also for ability of a plant to tolerate adverse environmental conditions. Thus identification of plasma membrane water channel genes (aquaporins) in ginseng provides extensive information for functional studies and the development of markers for salinity stress tolerance. Methods and Results : For salinity treatment, the plants were grown for 4 weeks in culture medium gelled with 0.8% Phytoagar, and the old media were replaced with the fresh medium containing NaCl at 0, 50, 100, 200 and 400 mM, respectively. The samples for stress treated and non-stressed plants were collected from 6h to 72h, and frozen immediately into liquid nitrogen. According to the sequence information from the assembled transcripts, four primer pairs were designed from the aquaporin gene regions. In order to determine the pattern of aquaporins expression in ginseng seedlings to salinity stress, we conducted semi-quantitative RT-PCR. Conclusion : A tonoplast intrinsic protein 1 (TIP1)-type aquaporin is not only believed to be essential for plant life, but also to be beneficial for growth under salinity stress. Therefore, a deeper understanding of aquaporin genes in ginseng will be essential for crop improvement, which could help us to understand the molecular genetic basis for the ginseng genetic improvement and also provide the functional genetic resources for selective breeding and transgenic research.
        11.
        2016.05 서비스 종료(열람 제한)
        Background : This study was carried out to understand the effect of seedling weight (SW) on growth and flowering in Panax ginseng. Methods and Results : The testing materials were Chunpoong (CP), Yunpoong (YP) and Jakyeongjong (JK). The increase of seedling (1yr) weight led to an increase in ratio of flowering plant and in number of flower per plant. The seed setting rate of two year-old plant (CP, YP, JK) increased with increase of SW at the planting time (PT) and number of flower per plant of three year-old plant (CP, YP) increased also. In the two year-old plant (JK), the ratio of three leaves per plant was 8.8, 19.6, 31.0, 42.0, 44.7 and 58.2%, respectively, in the SW of >0.6, 0.6~0.8, 0.8~1.0, 1.02~1.2, 1.2~1.4 and 1.4g<. The growth of ginseng plant was good with increase of SW at the PT. Conclusion : There was a highly positive correlation between seedling weight and flowering characteristics.
        12.
        2016.05 서비스 종료(열람 제한)
        Background : Due to immature development of embryo in ripened berries, dehiscence process is required for the proper germination of ginseng seeds. Such process involves the preparation of the container with alternating layers of seed and moist sand. In order to make sand fully moist, water sprayer has been usually used by farmers, which is labor intensive, time consuming and causing uneven sand moisture. Methods and Results : In this study, we investigated the effects of different stratification methods on dehiscence ratio of ginseng seeds. Ginseng seeds were stratified for 90 days in a total of 12 different treatments and the dehiscence ratios were compared; drainage methods, drainage time, the ratio between ginseng seeds and sand, and etc. Seed stratification process was performed according to the guideline of ginseng GAP. One thousand ginseng seeds were used for each treatment. It was found that the average of dehiscence of the 12 treatments was 84.6 %. The highest dehiscence ratio (90.3 %) was observed in the seeds that were treated with water soaking, immediately followed by drainage. Higher ratio was also observed in the seeds that were soaked for 60 min, followed by drainage. Therefore, our findings indicate that ginseng seeds soaked in water less than 60 min could dehisce more efficiently than traditional method. Conclusion : Our study demonstrated that ginseng seeds that are subjected to water soaking and then drainage showed better ration of dehiscence. This method will eventually decrease the time and labor used for seed stratification.
        13.
        2016.05 서비스 종료(열람 제한)
        Background : This study was conducted to determine the impact of temperature elevated and the effect of transplanting times based on climate change scenario on growth of 2-year-old korean ginseng (Panax ginseng C. A. Meyer.) in temperature gradient chambers (TGC). Methods and Results : As a plant materials, ‘Yunpoong’ was cultivated in TGC at ambient temperature(Amb), Amb+2℃, Amb+4℃ and Amb+6℃ respectively. Ginseng was also transplanted on March 29, April 12 and 26 respectively. Investigation on characteristic of aerial parts were carried out on 28, 56, 84 and 112 days after transplanting and characteristic of roots were conducted on October 19. As transplanting time was faster and temperature was higher, the growth of aerial parts were increased. Compared with those of ginseng transplanted on March 29 with Amb, the root weight which tend to decrease depending on late transplanting time and high temperature decreased about 11.1%, 35.4% and 42.4% in Amb+ 2℃, Amb+4℃ and Amb+6℃ respectively. Ginseng transplanted on April 12 and 26 decreased about 20.9%, 33.9% respectively. Conclusion : Consequently, the more transplanting time extend, the more quantity increased in all temperature treatment. So, it is possible to increase in quantity to advance transplanting time although high temperature will be caused by the climate change.
        14.
        2016.05 서비스 종료(열람 제한)
        Background : When ginseng seeds were gathered, the seeds were unripe. To grow immature embryo definitely, special treatment called dehiscence must be performed. Even though dehiscence is completed, most ginseng seeds are on enforced dormancy. The breaking seed dormancy is generally achieved using cold treatment. Also it is reported that gibberellin treatment can replace the treatment. It is very time consuming process in order to develop new ginseng cultivar because ginseng flowers after 3 years of growth. To shorten the ginseng breeding period, it is necessary to establish fast generation progress. Therefore, this study examined the possibility of breaking seed dormancy of ginseng using GA3 treatment and alternating temperature. Methods and Results : Seeds were obtained from local variety fruit which is not inbred. Gibberellin of 100 ppm was treated at seeds for 24 hours. Fixed cold condition was treated on both –2℃ and 2℃. Alternating cold condition was treated on 2℃ and then –2℃, finally 2℃. Fixed and alternating temperature was continued for 15, 30, 45, 60, 90 days that 15 days of alternating temperature is first 2℃ for 5days and then -2℃ for 5days, finally 2℃ for 5days. The other treatment periods such as 30, 45, 60, 90 days mean 10, 15, 20, 30 days respectively. Each of 48 seeds were sowed on tray in greenhouse at 3 replication. Experimental plot was completely randomized. Conclusion : Seeds untreated with GA3 were germinated little and there is no difference between 2℃ and –2℃. Alternating temperature until 60days made no difference with fixed temperature but germination rate increased up to 70.8% when seeds were treated for 90days. Germination of seeds treated with GA3 is much higher than untreated seeds especially combined with alternating temperature.
        15.
        2011.10 KCI 등재 서비스 종료(열람 제한)
        A chemical, MNU-induced hulless barley mutant line designated as 'Mutant 98 (M98)' was developed from a Korean hulless waxy barley cultivar, 'Chalssalbori'. The objective of the study was to determine the genetic basis of 'M98' and the possibility of using 'M98' as breeding parent to improve lysine level. Compared to 'Chalssalbori', 'M98' had large embryo and higher lysine content in both the embryo and endosperm. Significantly different lysine content in 'M98' and the other high-lysine barley mutant stocks was observed for two years. However, the genotype by year interaction was not significant. 'M98' was higher than the other high-lysine barley mutant stocks in the percentage of lysine of total amino acid composition (0.75%). The trait of shrunken endosperm of 'M98', which was typical in the high-lysine mutants, was inherited by a single recessive gene. Based on seed morphology and lysine content of F1 seeds, 'M98' had a genetically different gene from the other high-lysine mutants for shrunken endosperm. Segregation of F2 for plump/shrunken endosperm did not fit the expected ratio of Mendelian inheritance except for only one cross combination (GSHO1784 (lys1)/M98). The amino acid analysis of F5 and F6 progenies from the cross between 'M98' and 'Chalssalbori' revealed that the attempt to increase the range of lysine content of plump lines did not go beyond the limit of the average high-lysine barley germplasm.