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        검색결과 36

        1.
        2024.04 구독 인증기관·개인회원 무료
        Entomopathogenic fungi serve as eco-friendly alternatives to chemical pesticides. In this study, we investigate the interactions between mosquitoes and Metarhizium anisopliae JEF-157, which showed high insecticidal activity against mosquitoes, by RNA-seq analysis. RNA from mosquitoes was extracted at the median lethal time to identify changes in gene expression. The results showed 580 genes were up-regulated, while 336 genes were down-regulated in fungal treated mosquitoes. Up-regulated genes were related to metabolic and cellular processes such as cytochrome P450, DNA replication, and apoptosis. Down-regulated genes were involved in metabolism pathways such as lysosome, starch and sucrose metabolism, and fatty acid biosynthesis. These results are crucial for elucidating the mechanisms of fungal invasion and interaction in insects, providing insights for future pest management strategies.
        2.
        2024.04 구독 인증기관·개인회원 무료
        Entomopathogenic fungi have been studied to control insect pests as an alternative to chemical insecticides. However, all fungi haven't a high virulence against pests. In this study, we compared the biological characteristics of Metarhizium anisopliae strains. First, we selected four M. anisopliae strains and compared the thermotolerance, conidial productivity, and virulence. For the thermotolerance test, conidial suspensions were exposed to 0, 30, 60, and 90 min at 45 °C. As a result, the conidial germination rates were over 95% when exposed for 0 min but, were 64, 37.7, 6, and 3% when exposed for 30 min at 45°C, respectively. To compare conidial productivity, 200g of millet were used and inoculated with a conidial suspension of 1 ml (1×107 conidia/ml). Conidial productivity was investigated after 14 days. As a result of conducting a virulence test against mealworms using a spray method, differences in virulence between strains were confirmed.
        3.
        2024.04 구독 인증기관·개인회원 무료
        Five insecticides (Acrinathrin, Dinotefuran, Emamectin benzoate, Chlorfenapyr and fluxametamide) approved for tomato cultivation were evaluated in Frankliniella occidentalis populations collected from Chungcheong province (Cheongyang, Chungju and Gongju). Leaf dip bioassay was used to evaluate resistance levels (LC50). Bioassays on Acrinathrin demonstrated higher LC50 concentration in evaluated populations. In particular, the Chungju population was 745.61 times the recommended concentration of the insecticide. Other remarkable resistance levels were recorded for the Dinotefuran with 435.06 times and 196.29 times the recommended concentrations for the populations from Chungju and Gongju, respectively. Bioassays for Emamectin benzoate, Chlorfenapyr and Fluxametamide showed low resistance to insecticides in the evaluated populations.
        4.
        2024.04 구독 인증기관·개인회원 무료
        Yellow flower thrips (WFT), Frankliniella occidentalis is mainly controlled using chemical control methods. But the continuous use of chemical pesticides in greenhouse may contribute to development of insecticide resistance. Therefore, in this study, we evaluated the insecticidal activity of eleven insecticides against the WFT occurring in greenhouse pepper cultivation in the Gyeonggi province. The results showed no resistance in treatments with emamectin benzoate, fluxametamide, and flometoquin while high levels of resistance were recorded in treatments with acrinathrin, acetamiprid, and dinotefuran. The Anseong and Yeoju population was more resistant against spinetoram and chlorfluazuron, respectively, than populations from other regions.
        5.
        2022.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 액체감쇠역전회복(FLAIR) 시퀀스를 대체하였던 방법 중에 비교적 간단하면서 높은 재현성을 나타내었던 고신호 강도제거 원리를 MAGiC에 적용하여 MAGiC-FLAIR와 기존의 고속스핀에코-FLAIR 영상과 비교하여 고신호 강 도제거영상의 유용성과 임상적으로 유의미한 기준을 제시하고자 하였다. 연구방법은 MAGiC 적용 후 MAGiC-FLAIR와 MAGiC-고신호 강도제거 영상을 재구성하여, 기존의 고속스핀에코-FLAIR 영상과 각각 정성적, 정량적 평가를 비교하였 다. 정성평가결과 MAGiC-고신호 강도제거는 MAGiC-FLAIR 보다는 월등히 우수하며, 고속스핀에코-FLAIR와 유사한 결과를 보였고, 정량평가결과 MAGiC-고신호강도제거는 MAGiC-FLAIR보다 백질과 회백질 대조도는 더 우수할 뿐만 아 니라, 뇌척수액의 신호 억제도 우수한 결과를 나타냈다. Synthetic 영상을 통하여 획득한 다양한 대조도 영상 중 FLAIR의 부정확도를 고신호 강도제거기법을 적용한다면 진단적 가치를 개선하여 제공할 수 있을 것이다.
        4,000원
        6.
        2022.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 국내산 돌미나리에서 GABA생성능이 있 는 신규 유산균을 분리, 동정한 결과, Enteroccoccus casseliflavus로 확인되었다. 최근까지 Lactobacillus속과 같 은 GABA 생성 유산균에 대한 보고는 많이 되고 있고, 일 부 Enterococcs속 유산균도 보고되고 있으나 E. casseliflavus 종에 대한 보고는 없었다. 따라서 본 연구에서는 E. casseliflavus PL05 균주에 대한 GABA 생성 최적 조건을 찾기 위하여 배지의 유형, 생육 온도, 초기 pH 조건, 배양 시간, MGS 농도 및 탄소원을 포함한 다양한 조건을 테스 트하였다. PL05 균주는 MRS 혹은 TSB 배지보다 BHI 배 지에서 생육이 잘 되었으며, 배지의 초기 pH는 7-9 조건 에서 가장 생육이 왕성하였고, GABA 생성 조건 역시 유 사한 결과로 확인되었다. GABA의 기질에 해당하는 MSG 의 농도별 GABA 생성량을 조사한 결과, 7%에서 가장 높 은 생성량을 나타내었으나 5%에서도 유사한 수준으로 확 인되어 효율적인 측면에서 5%가 적합할 것으로 판단된다. 탄소원에 따른 생육 및 GABA 생성량은 말토오스를 사용 하였을 때 가장 높은 것으로 확인되었고, 이러한 최적의 조건들로 최종 테스트를 진행한 결과, 24시간째 140.06±0.71 mM의 GABA가 생성되었고, 전환율은 78.95%로 확인되 었다. 또한 반코마이신을 포함한 10개의 항생제에 대한 감 수성을 조사한 결과 내성이 없는 것을 확인하였다.
        4,000원
        10.
        2019.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        To enhance mechanical properties through improvement of dispersion stability of carbon black (CB) in epoxy resins, fluorine functional groups were introduced on the CB surface by fluorination. The changes in the chemical properties and dispersion stabilities after fluorination were evaluated with different partial pressures of fluorine gas. The mechanical properties of the fluorinated CB/epoxy composites were evaluated by the test of tensile, impact strengths and creep behavior. The fluorinated CB/epoxy composites showed approximately 1.6 and 1.1 times enhancement in the tensile and impact strengths compared to that of neat epoxy, respectively. Moreover, when a constant load was applied at 323 K, the fluorinated CB/epoxy composites lasted longer and had smaller strain changes than those of the raw CB/epoxy composites. Thus, well-dispersed CB by fluorination in epoxy resins effectively transfers mechanical stress.
        4,000원
        12.
        2016.04 구독 인증기관·개인회원 무료
        The subfamily Pimplinae currently includes 1,686 worldwide species in 45 genera. 36 species in 16 genera have been recorded from South Korea. Among them, the genus Delomerista is a small sized group in the subfamily Pimplinae with 18 described species from palaearctic, nearctic, oriental regions. The South Korean Delomerista wes newly recorded for the first time from South Korea in this study. The genus Perithous is a small group in this subfamily with 17 species from palaearctic, nearctic, oriental regions. The taxonomic study of the South Korean Perithous was initiated by Kim (1955) reported one species, Perithous scurra (Panzer, 1804). The genus Xanthopimpla is a moderate size in the subfamily Pimplinae with 261 species from entire regions, except nearctic and ethiopia regions. The existing South Korean Xanthopimpla includes only one species, Xanthopimpla punctata (Fabricius, 1781). In this study, we report six unrecorded species, Delomerista mandibularis (Gravenhorst, 1829), Delomerista pfankuchi Brauns, 1905, Perithous albicinctus (Gravenhorst, 1829), Perithous townesorum (Gupta, 1982), Perithous speculator Haupt, 1954 and Xanthopimpla clavata Krieger, 1914 of subfamily Pimplinae from South Korea.
        15.
        2014.04 구독 인증기관·개인회원 무료
        The Riptortus (stinkbug) has a specialized symbiotic organ, M4 midgut, to harboring symbiont Burkholderia. M4 midgut is located in abdomen and surrounded with insect hemolymph. Recently our group demonstrated that symbiotic Burkholderia showed different physiology after adapting in M4 gut compare with in vitro cultured Burkholderia. And population of symbiotic Burkholderia in the M4 midgut is regulated by special organ. However, the molecular mechanism to prevent spreading and migrating symbiont bacteria to other host tissues from symbiotic organ is not clear. Therefore, we assumed that symbiont Burkholderia are susceptible to host humoral immunity after established infection in M4 midgut to prevent spreading and migrating into the other host tissues through Riptortus hemolymph. To prove this assuming, we tested the susceptibility and survival rate of symbiont Burkholderia in hemolymph of Riptortus in vitro and in vivo. We also examined the susceptibility of symbiont Burkholderia using purified antimicrobial peptides (AMP), pyrrhocoricin-like, thanatin-like and defensin-like AMPs. Finally, we tested inducing ability for AMPs by systemic infection of symbiotic Burkholderia. Gene expression of purified AMPs was not different after systemic infection of both symbiont and in vitro cultured Burkholderia. Surprisingly, in vitro cultured Burkholderia resisted on bacteria injected hemolymph and purified AMPs but symbiont Burkholderia were highly susceptible in bacteria injected hemolymph and purified AMP. These results suggest that symbiont Burkholderia can't survive in the hemolymph after escaping symbiotic organ. Moreover, humoral immunity of host Riptortus is important to prevent spreading and migrating symbiont Burkholderia into the other host tissue or organ from symbiotic organ.
        16.
        2013.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Isotropic pitch fibers were stabilized and carbonized for preparing carbon fibers. To optimize the duration and temperature during the stabilization process, a thermogravimetric analysis was conducted. Stabilized fibers were carbonized at 1000, 1500, and 2000℃ in a furnace under a nitrogen atmosphere. An elemental analysis confirmed that the carbon content increased with an increase in the carbonization temperature. Although short graphitic-like layers were observed with carbon fibers heat-treated at 1500 and 2000℃, Raman spectroscopy and X-ray diffraction revealed no significant effect of the carbonization temperature on the crystalline structure of the carbon fibers, indicating the limit of developing an ordered structure of isotropic pitch-based carbon fibers. The electrical conductivity of the carbonized fiber reached 3.9×10⁴S/m with the carbonization temperature increasing to 2000℃ using a four-point method.
        4,000원
        17.
        2013.04 구독 인증기관·개인회원 무료
        The Diadegma fenestrale is known as parasitoid on potato tuber moth, Phthorimaea operculella and diamondback moth, Plutella xylostella. The Diadegma genus is reported to have symbiotic virus, ichnovirus, D. fenestrale Ichnovirus (DfIV) was identified from this species which is a first report. DfIV showed typical ichnovirus shape with two membranes surrounding the virus capsid. To identify DfIV genes, whole genome sequencing based on GS-FLX was conducted using purified total DfIV genomic DNA extracted from D. fenestrale calyx. About sixty ORFs were analyzed and several typical ichnovirus gene families were detected such as cys-motif, repeat element, vinnexin and vankyrin. Present study was focused on the gene expression patterns in two different lepidopteran hosts.
        18.
        2012.10 구독 인증기관·개인회원 무료
        We investigated the molecular and kinetic properties of two acetylcholinesterases (AmAChE1 and AmAChE2) from the Western honey bee, Apis mellifera. Western blot analysis revealed that AmAChE2 has most of catalytic activity rather than AmAChE1, further suggesting that AmAChE2 is responsible for synaptic transmission in A. mellifera, in contrast to most other insects. AmAChE2 was predominately expressed in the ganglia and head containing the central nervous system (CNS), while AmAChE1 was abundantly observed not only in the CNS but also in the peripheral nervous system/non-neuronal tissues. Both AmAChEs exist as homodimers; the monomers are covalently connected via a disulfide bond under native conditions. However, AmAChE2 was associated with the cell membrane via the glycophosphatidylinositol anchor, while AmAChE1 was present as a soluble form. The two AmAChEs were functionally expressed with a baculovirus system. Kinetic analysis revealed that AmAChE2 has approximately 2,500-fold greater catalytic efficiency toward acetylthiocholine and butyrylthiocholine than AmAChE1, supporting the synaptic function of AmAChE2. In addition, AmAChE2 likely serves as the main target of the organophosphate (OP) and carbamate (CB) insecticides as judged by the lower IC50 values against AmAChE2 than against AmAChE1. When OP and CB insecticides were pre-incubated with a mixture of AmAChE1 and AmAChE2, asignificant reduction in the inhibition of AmAChE2 was observed, suggesting a protective role of AmAChE1 against xenobiotics. Taken together, based on their tissue distribution pattern, molecular and kinetic properties, AmAChE2 plays a major role in synaptic transmission, while AmAChE1 has non-neuronal functions, including chemical defense.
        19.
        2012.05 구독 인증기관·개인회원 무료
        The Diadegma fenestrale was known as parasitoid on potato tuber moth, Phthorimaea operculella and diamondback moth, Plutella xylostella. This species, genus Diadegma are first reported from Korea. DfIV showed typical ichnovirus shape which two membranes surround virus capsids. The genome contents of DfIV consist about sixteen double-stranded DNA segments ranging 2 to 6 kb. To identify DfIV genes, whole genome sequencing based on GS-FLX was conducted using purified total viral DNA extracted from D. fenestrale calyx. About sixty ORFs were analyzed and several typical polydna virus gene family detected such as cys-motif, rep, vinnexin and vankyrin. This is the first report of DfIV and these lepidopteran host immune suppression genes will be deeply identified.
        20.
        2010.10 구독 인증기관·개인회원 무료
        The genus Gonioctena Chevrolat is distributed in the Holarctic and Oriental regions, with more than 80 species. Many species of the genus have great similarity in external morphology and coloration, often cause misidentifications. Thus, the shape of the aedeagus is mainly used to distinguish closely related species. Fifty-four species, more than half of the known taxa, occur in northeastern Asia, including 18 species in the Russian Far East, 29 in China, 11 in Korea, and 18 in Japan. Among these, G. gracilicornis Kraatz (type locality: Amur) is widely distributed in Russia, China, Mongolia and Korea. However, extensive investigation on Gonioctena in Korea revealed that the Korean population of G. gracilicornis differs from that of the Russian by the coloration, the puncturation of pronotum, and the shape of aedeagus. The purpose of this study is to describe a new species of Gonioctena that was previously misidentified as G. gracilicornis. A key to Korean Gonioctena, distribution, and host plant are also provided.
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