검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 71

        21.
        2018.04 구독 인증기관·개인회원 무료
        지의류 추출물이 흰줄숲모기(Aedes albopictus)에 대하여 살충활성 및 생장 억제에 미치는 영향을 조사하였다. 2종의 지의류의 메탄올 추출물이 흰줄숲모기 3령 유충에 미치는 치사농도, 사충수, 생장억제를 알아보기 위한 실험을 진행한 결과Parmelia sp.엽상체 추출물경우 LC50농도는 0.13%로 나타났으며 Porpidia albocaerulescens의 LC50농 도는 0.45%로 나타나 Parmelia sp.의 추출물이 더 높은 살충활성을 보였다. 24h, 48h, 72h의 노출시간 따른 농도별 사충 수를 조사한 결과, 전반적으로 지의류의 메탄올 추출물이 고농도일수록, 노출시간이 길어질수록 유충의 사충 수는 증가하였다. Parmelia sp. 엽상체의 추출물에서 사육한 유충의 경우 용화시간은 대조군보다 지연되었고, 추출물의 농도가 높을수록 더 많은 시간이 지연된 것으로 보아 지의류 추출물이 흰줄숲모기 유충의 생장을 억제하는 효과가 있음을 확인하였다.
        25.
        2016.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Most previous studies on dinoflagellates in Korean coastal areas were conducted without morphological descriptions and illustrations of the observed dinoflagellates. This indicates that the species and diversity of dinoflagellates may have been respectively misidentified and underestimated in the past, probably due to cell shrinkage, distortion and loss caused by sample fixation. This study provides information on the morphological observations of four dinoflagellate orders (Prorocentrales, Dinophysiales, Gonyaulacales and Gymnodiniales) from Jangmok Harbour in Jinhae Bay, Korea. The unfixed samples were collected weekly from December 2013 to February 2015. A total of 13 genera and 30 species were identified using light and scanning electron microscopy, although some samples were not clarified at the species level. Harmful dinoflagellates, Prorocentrum donghaiense, Tripos furca, Alexandrium affine, A. fundyense, Akashiwo sanguinea and Cochlodinium polykrikoides, were identified based on the morphological observations. The results also reflect the occurrence and identification of dinoflagellates that had not been previously recorded in Jangmok Harbour.
        4,000원
        26.
        2016.07 구독 인증기관 무료, 개인회원 유료
        The increasing competition in recent years made more and more firms regard strategic alliance as an important alternative and solution to respond to fierce competition. As a kind of system arrangement among firms, the concept of strategic alliance was first proposed by Hopland and Nigel in the early 1980s, who defined strategic alliance as the collaboration mode in which two or more firms, aiming at joint-owned both market and resources, formed the kind of cooperation to enhance advantages, share risk or cost, and also mutual flow of production factors via different kinds of contracts or agreement. However, even before this definition, many firms have already begun their alliance strategies practices. As a cooperative form, strategic alliance, no matter its specific types, becomes one key choice for firms to acquire, maintain and enhance their market shares and positions. Shrader (2001) found that collaboration to foreign firms become key methods for newly-founded firms and small firms to enter foreign markets, which can bring these firms with suitable knowledge and market information, making these firms expand even faster with lower costs and market risks. The enhancing pace of globalization and internationalization triggered firms’ attentions to external markets, Archibugi and Iammarino (2002) found that fierce changes in internal market forced firms to expand their market and product scopes, making more and more firms realize product and R&D internationalization by searching, choosing and collaborating with foreign firms. Dong and Glaister (2006) found Chinese firms cared more about market positions, international expansion and technology exchanges, while foreign firms tended to enter to Chinese market and learn how to operate in China via strategic alliances. Although, many scholars brought out managerial practices of firms’ strategic alliances, and had already formed theoretical foundations, researches related to market orientation, especially how alliance firms establish and realize their strategic goals and performance goals under market motivation is still lack of studies. In reality, the mechanism how firms’ alliance intention transformed into their strategic or performance goals is still in the black box. Taken alliance firms as research objectives, this paper tends to explore how firms constructed strategic alliance due to market-orientation realize their strategic or performance goals via choice of patent strategies. We introduced patent strategies to establish the matching model, to analyze how firms market orientation influence choices of patent strategies, and their mutual effects on firms innovative performance, in hope to provide to the future studies and managerial practice how firms can choose the reasonable and effective alliance partners according to their own strategic and performance goals. Based on differentiation of market access and market extension motivation, we pointed out that, in order to realize the transformation from alliance motivation to innovation performance, alliance firms had to choose and determine among a set of practical and operational plans. Patent strategies, as a kind of operational plan, were conducive to transformation from alliance motivation to innovation performance. With the framework of market motivation, patent strategy and firms innovative performance, we put forward the hypotheses on how market motivation affect firms’ choices of patent strategies, and also the joint effects of market motivation and patent strategies on firm innovative performance. We selected alliance firms in IT industry as samples, with data from Cooperative Agreements and Technology Indicators Database, USPTO and R&D Scoreboard released by Department for Business, Innovation & Skills of UK, we empirically tested effects of market motivation on choices of patent strategies, and also effects of market motivation and patent strategies on firms innovative performance. Results showed that: different market positions led to differentiated motivations and patent strategies in their strategic alliances, firms with relatively weak market positions tend to pursue strategic profile of patent defensive and leveraging strategies under market access motivation, while firms with strong positions would like to implement patent proprietary and leveraging strategies in market extension motivation. The implementation of patent defensive and leveraging strategies under market access motivation enhanced innovation efficiency of the firms with weak market positions. Since these firms focused more on market positions and opportunities, their market capitalization tended to improve, but the motivation and utilization of patent strategies had no effect on patent output. Similar to these firms, the ones with stronger market position were inclined to strengthen their market opportunities and improve their market capitalization. Results indicated that because of their stronger market positions, these firms showed lower awareness of innovation efficiency and their emphasis on patent output was not high either, which then led to the fact that both market extension motivation and patent strategies used had no effects on firms innovative performance measured by innovation efficiency or patent output.
        3,000원
        27.
        2016.04 구독 인증기관·개인회원 무료
        This study was performed to investigate the content of carotenoid (α-carotene, β-carotene, β-cryptoxanthin, capxanthin, lutein, lycopene, zeaxanthin) and physicochemical characteristics (size, color, dietary fiber, total tannin content) of unripen and ripen persimmons (Diospyros kaki) by seven cultivars. The length of the unripen and ripen persimmons ranged from 40.87-64.75 and 48.80-80.29 cm, the width were from 44.03 to 66.73 and 57.65 to 91.53 cm, respectively. Ripen persimmons were showed in the highest Hunter’s L, a and b values. Total tannin content were resulted of unripen- and ripen persimmons ranged from 7.58 to 19.80 and 2.36 to 5.85 mg/g. Total carotenoid content were from 1.09 to 6.45 and 7.46 to 29.46 μg/g, respectively. From the above results, unripen- and ripen persimmon fruit could be useful for the health functional food.
        28.
        2016.04 구독 인증기관·개인회원 무료
        Biological control has been tried for integrated pest management. It is often comparable, safe, and environment-friendly, making itself an alternative for chemical agents. Filamentous microorganisms, i.e., fungi and streptomystes, produce many kinds of useful metabolites, and some of them have been developed as a biocontrol agent. However, they still have a long way because of the concern of manufacturing cost. Therefore, process development was intensively studied to meet cost-effectiveness. Operating conditions of bioreactor, e.g., agitation and aeration, had an effect on biological and physiological responses such as mycelial morphology, oxygen and nutrient transfer. Understanding relationship between operating parameters and microbial responses in terms of growth, substrate and oxygen consumption, and production yield was critical for process development. This study dedicated to build strategies for mass production of biological control agent using aerobic filamentous microorganisms.
        29.
        2015.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The present in vitro study was conducted to examine the effect of buffer solubility of eight protein feeds (coconut meal, distillers grain, sesame meal, perilla meal, soy source cake, rape seed meal, soybean meal and lupine) on the fermentation characteristics, degradability of dry matter (DM) and crude protein (CP), and methane (CH4) production by rumen microbes. Buffer extraction increased pH (P<0.05 ~ p<0.001) of the culture solution but tended to lower ammonia- N concentration for all protein feeds. Total volatile fatty acids(VFAs) and each VFAs concentrations in all incubation was decreased by buffer extraction (P<0.01 ~ P<0.001). Also, molar proportion of acetate in 1h (P<0.001), 3h (P<0.01) and 12h (P<0.05) incubations and molar proportion of propionate in 1h (P<0.001), 3h (P<0.01), 6h (P<0.05) and 12h (P<0.05) were decreased by buffer extraction. But molar proportion of butyrate in 1h (P<0.001), 3h (P<0.01) and 6h (P<0.05) were increased by buffer extraction. The in vitro effective degradability of dry matter (P<0.001) and CP (P<0.001) was decreased by buffer extraction. The methane production (P<0.01~P<0.001) in all incubation was decreased by buffer extraction. The results from in the current study might be useful for diet formulation to improve the feed efficiency of the ruminant animals without massive loss of major nutrients.
        5,200원
        30.
        2015.02 구독 인증기관 무료, 개인회원 유료
        Benzene was oxidized by binary oxidants composed of nitric acid and hydrogen peroxide at 80℃. The product obtained was analyzed with gas chromatograph-mass spectrometer. Eight high value compounds, 2-nitrophenol, 2-chloro-6-nitrophenol, 4-chloro-2- nitrophenol, 2-chloro-4-nitrophenol, 2,4-dinitrophenol, 4-nitrophenol, 2,6-dinitrophenol and 2-chloro-4,6-dinitro-phenol were found, which they have high contents in the range from 4.28% to 32.52%. These compounds are very widely used in organic synthesis. e.g., synthesizing dye, medicines and chemical reagents, pesticide, explosive, polymer, etc.
        3,000원
        31.
        2013.10 구독 인증기관·개인회원 무료
        Proteinaceous insecticidal proteins, Cry proteins, from Bacillus thuringiensis (Bt) are insecticidal proteins that are highly active against several species of Lepidoptera. Thus, cry genes encoding these Cry proteins have been widely applied for construction of transgenic crops resistant to pest insects. In this study, through the 3D structure prediction and accompanying mutagenesis study for the Mod-Cry1Ac, 7 and 16 amino acid residues from domain I and II, respectively, responsible for its insecticidal activity against larvae of Spodoptera exigua and Ostrinia furnacalis were identified. We used site-directed mutagenesis to improve the insecticidal activity of Mod-Cry1Ac, resulted 31 mutant cry genes. These mutant cry genes encodes potent insecticidal proteins in the form of crystalline protoxins of 95 kDa. SDS-PAGE analysis of the recombinant polyhedra revealed that expressed Cry proteins was occluded into polyhedra and activated stably to 65 kDa by trypsin. When the insecticidal activities of these mutant Cry proteins against to larvae of P. xylostella, S. exigua and O. furnacalis were assayed, they showed higher or similar insecticidal activity compared to those of Cry1Ac and Cry1C. Especially, Mutant-N16 is considered to have the potential for the efficacious biological insecticide since it showed the highest insecticidal activity.
        32.
        2013.04 구독 인증기관·개인회원 무료
        Crystals of proteinaceous insecticidal proteins, Cry proteins, produced by Bacillus thuringiensis (Bt) have been generally used to control insect pests. In this study, through the 3D structure prediction and accompanying mutagenesis study for the Mod-Cry1Ac, 7 and 16 amino acid residues from domain I and II, respectively, responsible for its insecticidal activity against larvae of Spodoptera exigua and Ostrinia furnacalis were identified. To construct novel cry genes with enhanced insecticidal activity, we randomly mutated these 23 amino acid sequences by in vitro muti site-directed mutagenesis, resulting in totally 24 mutant cry genes. For further characterization, these mutant cry genes were expressed as a fusion protein with polyhedrin using baculovirus expression system. SDS-PAGE analysis of the recombinant polyhedra revealed that expressed Cry proteins was occluded into polyhedra and activated stably to 65 kDa by trypsin. When the insecticidal activities of these mutant Cry proteins against to larvae of P. xylostella and S. exigua were assayed, they showed higher or similar insecticidal activity compared to those of Cry1Ac and Cry1C. Especially, among them Mutant-N16 showed the highest insecticidal activity against to both of P. xylostella and S. exigua. Therefore, Mutant-N16 is considered to have the potential for the efficacious biological insecticide.
        33.
        2013.03 구독 인증기관 무료, 개인회원 유료
        Artificial insemination (AI) has been performed widely in swine industry using fresh liquid sperm instead of frozen type of sperm. However fresh sperm are not able to preserve more than three days with optimal motility and other sperm parameters for the successful fertilization, since in vitro stored sperm has an oxidative stress that resulted increase of abnormality and acrosome reation. To overcome these major problems, novel preservative formulation is needed to neutralize the oxidative stress and to provide suitable physiological environment for sperm in in vitro. In this study, naturally derived substances such as Poncirus trifoliate (Trifoliate orange), Garcinia mangostana (Mangosteen), pig placenta and testis extracts were tested as sperm preservative agents. Placenta extracts (PE), trifoliate orange extracts (TOE), testes extracts (TE) and mangosteen extracts (ME) were applied to analyze specific parameters for sperm motion characteristics individually and combinatorial. Each individual extract treatment can accelerate the sperm motility but noticeably TOE, TE and ME treatments exhibited the considerable and significant preservation of sperm motility. PE, TE and ME showed a significant (p<0.05) increase in ALH after one week. Further we evaluated the five different combinations of these extracts on sperm motility and its motion characteristics. Surprisingly even after one week ME, TOE and TE combination significantly preserved the sperm motility about 75%. It is noteworthy that unlike individual extract treatment, combination of ME, TOE and TE simultaneously protect the sperm motility and its motion characteristics. Taken together these data conclude that addition of ME, TOE and TE can be effective for preservation of pig sperm.
        4,000원
        37.
        2012.10 구독 인증기관·개인회원 무료
        Varieties of Bacillus thuringiensis (Bt) crystal proteins, Cry proteins, have so far been found as one of the most successful biological control agents which are safe to natural environments for a long time. Recently, cry genes encoding these Cry proteins have been widely applied for construction of transgenic crops resistant to pest insects. In this study, through the 3D structure prediction and accompanying mutagenesis study for the Mod-Cry1Ac, 7 and 16 amino acid residues from domain I and II, respectively, responsible for its insecticidal activity against larvae of Spodoptera exigua and Ostrinia furnacalis were identified. To construct novel cry genes with improved insecticidal activity, we randomly mutated these 23 amino acid sequences by in vitro muti site-directed mutagenesis, resulting in totally 24 mutant cry genes. For further characterization, these mutant cry genes were expressed as a fusion protein with polyhedrin using baculovirus expression system. SDS-PAGE analysis of the recombinant polyhedra revealed that expressed Cry proteins was occluded into polyhedra and activated stably to 65 kDa by trypsin. In the further study, we plan to investigate their insecticidal activity against Plutella xylostella, S. exigua and O. furnacalis larvae.
        38.
        2012.06 구독 인증기관·개인회원 무료
        SERPINB3 (also known Squamous cell carcinoma antigen 1, SCCA1) is involved in apoptosis, immune response, cell migration and invasiveness of cells. It has been investigated in various types of squamous cell carcinoma. Therefore we investigated the functional role of SERPINB3 gene in human epithelial ovarian cancer (EOC) using laying hens, the most relevant animal model. In 136 laying hens, EOC was found in 10 (7.4%). We compared the expression and localization of SERPINB3 using RT-PCR, quantitative RT-PCR, in situ hybridization and immunohistochemistry, and SERPINB3 activation was detected in chicken and human ovarian cancer cell lines using immunofluorescence microscopy. Thereafter, we examined the prognostic value of SERPINB3 expression in patients with EOC by multivariate linear logistic regression and Cox’ proportional hazard analyses. In present study, SERPINB3 mRNA was induced in cancerous ovaries (p< 0.01), and it was only expressed in the glandular epithelium(GE) of cancerous ovaries of laying hens. SERPINB3 protein was localized predominantly to the nucleus of glandular epithelium in cancerous ovaries of laying hens, and it was abundant in the nucleus of both chicken and human ovarian cancer cell lines. In 109 human patients with EOC, 15 (13.8%), 66 (60.6%) and 28 (25.7%) of those patients showed weak, moderate and strong expression of SERPINB3 protein, respectively. Strong expression of SERPINB3 protein was a prognostic factor for platinum resistance (adjusted OR, 5.94; 95% Confidence Limits, 1.21-29.15). Therefore SERPINB3 may play an important role in ovarian carcinogenesis and be a novel biomarker for predicting platinum resistance and a poor prognosis for survival in patients with EOC. This research was funded by the World Class University (WCU) program (R31-10056), Basic Science Research Program (2010- 0013078) through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science, and Technology and by the Next-Generation BioGreen 21 Program (No.PJ008142), Rural Development Administration, Republic of Korea.
        1 2 3 4