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        검색결과 37

        2.
        2023.10 구독 인증기관·개인회원 무료
        The two-spotted spider mite, Tetranychus urticae Koch, is one of the most important agricultural pests. Therefore, we screened fifteen compounds from natural products for their spatial repellent and oviposition deterrent activities against T. urticae in the laboratory by using two-choice and no-choice tests. In the bridge two-choice test, nine compounds showed the spatial repellent effects on T. urticae at 20 mg dose, resulting in reduced numbers of eggs. Among the nine compounds, at 2 mg dose, two compounds were selected as having more spatial repellent activity than the others. The two compounds also showed spatial repellent and oviposition deterrent effects in the two-choice test from hosts. In the no-choice test from a host, the spatial repellent effects of the two compounds to T. urticae were significantly stronger than that of controls. These results suggest that the findings can be used as potential agents for the prevention and population control of T. urticae in the field.
        3.
        2023.10 구독 인증기관·개인회원 무료
        The cotton aphid, Aphis gossypii glover (Hemiptera: Aphididae), is the world-wide agriculture pest and has the ability to become resistant to many pesticides. Hence, we conducted behavioral tests on apterous and alate aphids for series compounds from natural products by using a two-choice test, a no-choice test, a host choice test and electroantennography (EAG). As a result, we found 3 out of 30 compounds for apterous aphids and 2 out of 15 compounds for alate aphids, both of which showed powerful repellent effects on these aphids. In this study, we suggest that our findings could be useful and eco-friendly spatial repellents for controlling cotton aphid.
        4.
        2023.10 구독 인증기관·개인회원 무료
        기존에는 생산되는 키틴과 키토산의 대부분이 게, 새우등 갑각류 껍질에서 유래하였다. 하지만 어업에 의존하 는 기존 갑각류 비해 친환경적이며 품질 유지에 이점을 가지는 곤충으로부터 유래한 키틴이 최근 주목 받기 시작 하며 연구가 활발해지고 있다. 이에 키토산이 남조류의 응집을 통해 녹조 제거 효과를 가지며 기존에 녹조를 억제하기 위해 널리 사용되던 살조제들이 독성을 띠어 환경에 악영향을 미치는 문제를 해결할 수 있다는 연구를 참고하여 매미 탈피각으로부터 추출한 키토산을 녹조 방제에 활용해 보고자 하였다. 매미 탈피각으로부터 키토 산을 추출하고 대표적인 녹조 원인종인 Microcystis aeruginosa 배양 후 추출한 키토산을 처리하여 녹조의 응집 효과를 관찰하였다. 본 연구에서 새로운 키토산 추출 원으로서 매미 탈피각의 가능성을 제시하였으며 이를 녹조 방제에 활용함으로써 버려지는 자원인 매미 탈피각의 활용 방안을 제시하였다.
        7.
        2022.10 구독 인증기관·개인회원 무료
        Kori-1, the nuclear power plants in South Korea, first started operation in April 1978 and was suspended permanently in 2017. The saturation rate time of spent nuclear fuel generated by major nuclear power plants operating in Korea are getting closer. If we fail to dispose spent nuclear fuel, which is equivalent to high-level radioactive waste, the nuclear power plants will have to be shutdown. High-level radioactive waste is permanently disposed through a deep geological disposal system because it contains long-term half-life nuclides and emits high energy. To select the deep geological disposal site and construct the disposal facilities, it is necessary to establish appropriate regulatory policies accordingly. The status of database construction in OECD-NEA, NRC, SITEX, and IAEA, which provides safety regulations for deep geological disposal system, stipulates each requirement for dismantling nuclear power plants. However, details such as specific figures are not specified, and guidelines for the disposal of high-level radioactive wastes are not clearly distinguished. In Korea, the CYPRUS program, an integrated database system, has been developed to support comprehensive performance evaluation for high-level waste disposal. However, due to several difficult situations, maintenance and upgrades have not been performed, so the research results exist only in the form of raw data and the new research results have not been reflected. Other than that, there is no preemptive basis for regulating the deep geological disposal system. With real-time database, we can develop a regulatory system for the domestic deep disposal system by systematically analyzing the regulatory condition and regulatory case data of international organizations and foreign leading countries. The database system processed and stored primary data collected from nuclear safety reports and other related data. In addition, we used relational database and designed table to maximize time and space efficiency. It is provided in the form of a web service so that multiple users can easily find the data they want at the same time. Based on these technologies, this study established a database system by analyzing the legal systems, regulatory standards, and cases of major foreign leading countries such as Sweden, Finland, the United States, and Japan. This database aims to organize data for each safety case component and further prepare a safety regulatory framework for each stage of development of disposal facilities suitable for the domestic environment.
        9.
        2019.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was carried out to produce stable evening primrose oil in water emulsion by using various emulsifier with HLB (8.6, 12, 16.7), concentration (0-45%) and emulsification methods such as high-speed emulsification (7,000 rpm, 2 min) and high-pressure homogenization (10,000 psi, 1 cycle). And then properties of evening primrose oil in water emulsion was evaluated with keeping at room temperature and 40oC during 28 days. Lower HLB 8.6 and high viscosity emulsifier added emulsions were not appropriate for high-pressure homogenization and were separated in a day. The optimum emulsification condition was HLB 12 and high-pressure homogenization (10,000 psi, 1 cycle) for evening primrose oil in water emulsion. These emulsions produced by optimum condition were not separated with the aqueous phase and the oil phase and they were nano-sized around 200 nm, higher zeta-potential (±mV), mono-polydispersed (<0.3), and less oxidized (<0.4) during 28 days.
        4,000원
        10.
        2019.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, commercial activated carbons (ACs) were upgraded by different activation methods, and the gases generated during the activations were defined and quantified. The chemical activation commonly applied for upgrading ACs uses complex reactions, involving pyrolysis, physical, and chemical reactions. The ACs based on wood materials were characterized by elemental analysis, N2 physisorption, Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, and temperature-programmed desorption mass spectrometry. The patterns and composition of the generated gases were analyzed by gas chromatography and X-ray diffraction; high-resolution scanning electron microscopy was also used to characterize the activated carbon. The AC was mostly decomposed to CO2 by pyrolysis and physical activation, while CO was mainly detected during chemical activation from the K2CO3 produced by the reactions between CO2 and K2O. The detected amounts of generated gases were differed at various KOH ratios and residence times. The highest surface area obtained in this study was 2000 m2/g at the optimum ratio of AC and KOH (1:2).
        4,000원
        12.
        2018.11 구독 인증기관·개인회원 무료
        Cryopreservation of bovine embryos is used to efficiently implant surrogate mothers. It has been widely accepted that high lipid content in the oocyte interrupts its survival during freeze-thaw cycles. Serum component in the culture medium is thought to increase the embryo`s lipid contents. Conversely, L-carnitine stimulates lipid metabolism by transporting long chain fatty acids into the mitochondria. Objective of this study was to analyze the effect of L-carnitine supplementation in IVM medium and defined IVC medium on the development, lipid contents and the cryosurvival of bovine IVF embryos. 0.0, 1.5, 3.0 and 6.0 mM L-carnitine was supplemented in IVM medium, respectively (IVM-LC 0.0, LC 1.5, LC 3.0 and LC 6.0). Development rate from the 2cell to the morula stages was higher in IVM-LC 3.0 groups than those of IVM-LC 6.0 (p<0.05). But there were no significant differences among the other groups in the blastocyst rates and lipid content results. When 0.0, 1.5, 3.0 and 6.0 mM L-carnitine were supplemented in IVC medium (IVC-LC 0.0, LC 1.5, LC 3.0 and LC 6.0), development competence was not significantly different between those embryos. Lipid contents of embryos treated L-carnitine (IVC-LC 1.5, 3.0 and 6.0) were significantly lower than embryos of non-treated group. L-carnitine was supplemented 0.0, 1.5, 3.0, 6.0 mM during IVM and 3.0 mM during IVC (LC 0.0 - 3.0, LC 1.5 – 3.0, LC 3.0 – 3.0, LC 6.0 – 3.0) and cryosurvival of blastocysts confirmed after freezing-thawing. There were no significant differences on development, but LC 3.0 – 3.0 was significantly lower lipid contents than other groups. And LC 3.0 – 3.0 had better survival rates and hatched rates of blastocysts than LC 0.0 – 0.0. In conclusion, supplementation of L-carnitine in defined IVC medium decreases lipid contents. And L-carnitine supplementation improves cryosurvival and developmental ability of bovine IVF embryos.
        13.
        2018.11 구독 인증기관·개인회원 무료
        The early-onset familial Alzheimer's disease (EOFAD/ FAD), the less common type of Alzheimer's disease (AD) currently affects a vast number of individuals worldwide. This type is being inherited as an autosomal dominant fashion. Missense mutations on Amyloid precursor protein (APP) and Presenilins 1 and 2 (PSEN1 & PSEN2) are known as major genetic factors in FAD. Conversely, missense mutations on microtubule-associated protein tau (MAPT) are also thought to involve. Up to date, several triple-transgenic animal models with muted forms of the human APP, PSENs and MAPT have been reported. Compared to other animals, canines are more emotional and their disease signs can be easily diagnosed. This attempt was to develop a triple transgenic canine model for the AD. We have obtained the coding sequences of APP, PSEN1 and MAPT from Dana-Farber/Harvard Cancer Center DNA resource core at HMS and incorporated several common AD mutations. The transgenic construct is composed of hNSE (ENO2) promoter-driven three AD genes fused together with modified 2A sequences. It was transfected into the canine fetal fibroblasts which were then used to perform somatic cell nuclear transfer (SCNT). The viable transgenic embryos were obtained after in vitro culture and the GFP was detected. In this study, we have successfully produced viable triple transgenic canine cloned embryos using SCNT technique. These transgenic canine embryos will be further developed into canines with FAD. The transgenic canines will be a good candidate in the AD research field.
        16.
        2013.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The fact that flip-flops, one of many different types of unstable shoes, are light and relatively easy to put on, accounts for their popularity among people. But because flip-flops rely heavily on the support of a single thong between your first and second toes, they impose a huge amount of pressure onto lower leg. Thus in the following experiment we tried to examine the different effects of flip-flops and running shoes in terms of their effect on muscle activity and fatigue of tibialis anterior and gastrocnemius during walking. In order to measure an electromyogram we used Free EMG system. 10 men and 10 women in running shoes ran on treadmills for 15 minutes at 4.8km/h, 2 days later the same experiment was carried out, but this time, in flip-flops. p value turned out to be greater than .05 and thus there was no considerable difference between the effects of flip-flops and running shoes on muscle activity and fatigue during walking. Therefore we conclude that despite the fact that flip-flops are considered unstable, their effects on muscle activity and fatigue of tibialis anterior and gastrocnemius are negligible.
        3,000원
        17.
        2012.10 구독 인증기관·개인회원 무료
        Among hemipteran insects which is the most important insect vector of plant viruses, small brown planthopper, Laodelphax striatellus, transmits the rice stripe virus (RSV) causing rice stripe disease. For effective control of RSV, it is important to understand interaction between RSV and L. striatellus. Therefore, in this study, expressed sequence tag (EST) databases were generated based on 454 GS-FLX pyrosequencing for comparative transcriptome analysis between nonviruliferous and RSV-viruliferous L. striatellus. By comparing the two EST libraries, we showed that 108 host genes were significantly up-regulated and 28 host genes were significantly down-regulated in viruliferous insects. Interestingly, genes encoding ribosomal proteins were mainly up-regulated in viruliferous L. striatellus, whereas genes related to translation were concentrated in the downregulated cohort. These RSV-dependently regulated genes may have important function in the behavior of planthopper or the transmission of RSV.
        18.
        2012.10 구독 인증기관·개인회원 무료
        Bacillus thuringiensis serovar mogi of a novel serogroup (H3a3b3d), which showed mosquitocidal activity against Anopheles sinensis and Culex pipiens pallens, was isolated from fallen leaves in Mungyeong city, Republic of Korea. In contrast to the complicated plasmid profiles of B. thuringiensis H3 serotype strains, the B. thuringiensis serovar mogi contained only megaplasmid (> 30 MDa) on which the toxin genes were occasionally located. Sequence analysis using 454-pyrosequencing revealed that the megaplasmid harbored at least seven putative cry genes, showing about 84%, 75%, 73%, 58%, 84%, 39% and 75% similarities in amino acid sequences with Cry27Aa, Cry19Ba, Cry20-like, Cry56Aa, Cry39ORF2, Cry8Ba and Cry40ORF2, respectively. These cry genes were cloned to the Escherichia coli-B. thuringiensis shuttle vector, pHT1K, and then introduced into an acrystalliferous B. thuringiensis Cry-B strain for further molecular characterization. To investigate the role of these genes in crystal production, the expression profiles of these toxin genes were analyzed by quantitative real-time PCR (qrtPCR) from the wild type strain as well as transformant strains. The results clearly indicate that the cry39orf2 was the dominant ingredient in the crystal. This novel 3a3b3d type strain, B. thuringiensis serovar mogi, could be used as a good resource for studying unknown mosquitocidal cry genes.
        19.
        2012.10 구독 인증기관·개인회원 무료
        The baculovirus expression system is one of the most popular methods used for the production of recombinant proteins but has several complex steps which have proved inherently difficult to meet a multi-parellel process. We have developed a novel recombinant bacmid, bEasyBm that enabling easy and fast generation of pure recombinant virus without any purification step. In the bEasyBm, attR recombination sites were introduced to facilitate the generation of recombinant viral genome by in vitro transposition. Moreover, extracellular RNase gene from bacillus amyloliquefaciens, barnase, was expressed under the control of Cotesia plutellae bracovirus early promoter. Therefore, only when the barnase gene was replaced to gene of interest, the bEasyBm could replicate in host insect cells. When the bEasyBm was transposed with pDualBac-EGFP and pDualBac-LUC respectively, there were no non-recombinant backgrounds were detected from unpurified BmEasy-EGFP or BmEasy-LUC stocks. In addition, the resulting recombinant virus, BmEasy-EGFP, showed comparable level of EGFP expression efficiency with the plaque-purified recombinant virus, BmEGFP, which was constructed using bBmGOZA system. Based on these results, high-throughput condition for generation of multiple recombinant viruses in a time was established.
        20.
        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.
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