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        검색결과 31

        21.
        2018.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        길초근 및 양강근정유를 유제 및 입제로 제형화한 후 이들의 급성어독성을 측정하였다. 잉어를 이용한 급성독성에 사용된 길초근 및 양강근 정유는 수증기증류법, 핵산을 이용한 용매추출법 및 초임계추출법을 이용하여 추출하였고 이들의 유제 및 입제의 급성어독성은 반수치사농도 (LC50)를 구하여 평가하였다. 길초근 및 양강근 원제 중 용매추출법으로 추출한 정유만이 어독성을 나타내었다. 길초근 및 양강근 추출법별 정유 이용한 유제의 급성어독성 평가한 결과 길초근의 경우 모든 추출법 대하여 독성을 나타내지 않은 반면에 양강근 정유는 추출법에 관계없이 모두 잉어에 대한 어독성이 관측되었다. 입제의 경우 길초근은 용매로 추출한 정유에서 독성이 나타났고, 양강근 정유의 경우 초임계추출법으로 추출한 정유 입제에서만 어독성이 관측되었다. 이러한 결과는 3급 어독성에 해당되는 것으로 환경 중 사용에는 문제가 없다고 사료된다. 살충효과가 뛰어난 양강근 정유의 경우 수증기증류법 및 초임계추출법으로 추출한 정유의 10 mg L-1 수준에서 노출된 잉어의 분자적 반응을 확인하여 cytochrome P450 1A 효소 및 glutathione S-transferase의 발현이 급격히 증가하였음을 확인하였고 이들은 수계환경 중 양강근 정유의 동태를 관찰하는 바이오마커로서 사용 가능하다고 사료된다.
        4,000원
        22.
        2018.10 구독 인증기관·개인회원 무료
        Phosphine (PH3) resistance in the stored-products insect pests has been reported throughout the world in various insect species, including Rhyzopertha dominica, Tribolium castaneum, and Cryptolestes ferrugineus, leading farmers and fumigators to identify new fumigation tools to control PH3-resistant insect pests in storage facilities. Understanding PH3-resistance mechanisms in insects might contribute to providing clues for the development of new chemicals, including fumigants, to control various PH3-resistant insects. A proteomic study has shown 15 decreased proteins in the PH3-resistant R. dominica (CRD343 strain) in comparison to the PH3-susceptible R. dominica, and among those 15 proteins, dihydrolipoamide dehydrogenase (DLD), a protein involved in the Krebs cycle, was identified (Park et al., 2008). The DLD polymorphisms responsible for genetic resistance have disulfide active sites for PH3 binding and are highly sensitive to arsenic exposure after mutagenesis in insects (R. dominica and T. castaneum) and Caenorhabditis elegans (Schlipalius et al., 2012). Here, two PH3- resistant S. oryzae strains were used to understand the development of PH3 resistance in these insects. Acute toxicity test by PH3 on the two PH3-resistant strains was undertaken followed by ethyl formate inhibition study on cytochrome c oxidase activity. The Lineweaver-Burk plots after inhibition studies showed there were significantly difference in inhibition mode between the resistant strains and the control. The RT-qPCR analysis and the next-generation sequencing of the mitochondrial DNA revealed significant changes in metabolism and energy production. Taken together, the PH3 resistance in S. oryzae was definitely acquired by the overall transformation of biochemical reactions to overcome PH3 toxicity.
        23.
        2018.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        An efficient, quick and low-cost extraction and clean up method for the determination of 14 polycyclic aromatic hydrocarbons (PAHs) in the agricultural water samples was optimized using gas chromatography-tandem mass spectrometry (GC-MS/MS). The extraction of the target compounds in water sample was carried out with acetonitrile, followed by partitioning promoted by the addition of salt. As a clean-up procedure, dispersive solid phase extraction was employed to purify the analytes of interest for GC-MS/MS analysis. This method was successfully applied for the quantification of PAHs in real water samples collected for the purpose of monitoring from the waterways located in Chungbuk (15 sites) and Gyeongbuk (6 sites), S. Korea. Phenanthrene (0.54 to 2.53 μg L-1) was detected in all the water samples collected from both the sites. Fluoranthene was detected in the water samples collected from the two sites in Gyeongbuk province, but other PAHs were not determined in these water sampling sites. Based on these results, the determined PAHs were conducted using an environmental risk assessment. The risk characterization ratios (RCRs) for phenanthrene ranged from 0.37 to 3.21. These RCR values referred to as risk was not controlled because RCR values of some sites were greater than 1. In conclusion, it is proposed that the optimized method in combination with GC-MS/MS could be successfully employed for the determination of PAHs in any environmental samples including water samples.
        4,000원
        24.
        2017.10 구독 인증기관·개인회원 무료
        Ethyl formate has been used for the control of insect pests by fumigation. However, there were not many reports toshow its target site of fumigant toxicity on insect pests since its first use in the agricultural industry. In the present study,we showed the presumable target sites of ethyl formate fumigation in insect pests using Myzus persicae nymphs. Afterethyl formate fumigation, the nymphs of this species were collected and the changes at the biochemical and molecularlevel were determined. The activity of cytochrome c oxidase (COX) was approximately two-fold higher after ethyl formatefumigation. In addition, the expression levels of acetylcholinesterase (AChE) decreased gradually with increasing ethylformate concentration. These two findings suggested that COX and AChE might be the major target sites of ethyl formatefumigation. In addition to these results, the analysis of lipid content using MALDI-TOF MS/MS identified 9 phospholipidsdifferently generated 2-fold higher in the ethyl formate-treated nymphs than that in the control nymphs, thereby leadingto changes in cell membrane composition in M. persicae nymphs. Therefore, the ethyl formate fumigation caused lethaleffects on M. persicae nymphs by changing COX activity, AChE gene expression, and phospholipid production.
        25.
        2017.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        To determine their acute toxicities on the earthworm (Eisenia fetida), six toxic chemicals were evaluated, according to the OECD guideline 207: sulfuric acid, methanol, methylethylketone, nitric acid, formic acid, and toluene. Sulfuric acid exhibited the maximum toxicity. The LC50 values of sulfuric acid, nitric acid, formic acid, and toluene were 20.5, 49.1, 55.5, and 534.5 μg cm-2, respectively. Toluene showed 26-fold lower toxicity than sulfuric acid. In this study, methanol and methylethylketone did not exhibit any toxicity to the earthworm. Further evaluation revealed that nitric acid, formic acid, and toluene exerted a change in the body weight of the chemically treated earthworms, whereas the other chemicals were ineffective. These results can be used for environmental risk assessment, when the chemicals are accidently discharged into the environment.
        4,000원
        26.
        2016.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Level and distribution of fourteen polycyclic aromatic hydrocarbons (PAHs) in the agricultural water samples collected in the waterways located in Gyeonggi and Gangwon, Korea were determined for monitoring and risk assessment. A simplified, fast but effective extraction and clean-up methods combined with gas chromatography tandem mass spectrometry (GC-MS/ MS) was employed to measure the concentration of the target compounds. The extraction of the analytes of interest in water sample (10 mL) was performed with acetonitrile (10 mL) and the salt. To purify the target PAHs, the clean-up procedure was employed with 2 mL tubes of dispersive solid phase extraction. The optimized method was validated with recoveries, method detection limit (MDL), accuracy and precision. Good recoveries for each PAHs at 10 and 25 μg L-1 were achieved (60 to 110%, with RSD <20%) with linearity (>0.99). MDL for all the analytes was achieved with 0.2 μg L-1. GC-MS/MS results showed that concentration of phenanthrene in the water samples from Gyeonggi (20 sites) ranged from 0.82 to 2.56 μg L-1 and from Gangwon (15 sites) ranged from 0.83 to 1.62 μg L-1. Other PAHs were not found in the water samples but the continuous monitoring for these areas were required.
        4,000원
        27.
        2016.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Essential oils (EOs) extracted from plants possess various biological activities and have been considered as natural insecticides due to their potent insecticidal activities. In regard to develop natural insecticides, EOs are formulated as an emulsifiable concentrate and their acute toxicity against to fishes were determined in a static condition using Cyprinus carpio. Coriander EO was used as an active ingredient mixed with ethanol for solvent and various surface active agents. The tested EOs were obtained from a commercial market, and three different extractions were also undertaken to produce EO using steam distillation, solvent extraction, and supercritical fluid extraction. Among the emulsifiable concentrate including a commercial coriander EO, surface active agents such as Tween 80, sodium dodecyl benzene sulfonate (SDBS), and mixture of SDBS and Nonidet showed acute toxicity to the fish. With the three different EO extraction, coriander EO obtained from supercritical fluids with Triton X-100 exhibited acute toxicity to C. carpio. Taken together, Tetgitol and Nondet are considered as surface active agents for the emulsifiable formulation of coriander EO.
        3,000원
        28.
        2013.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        약용식물 중 잔류농약의 안전성을 평가하고자 2012년 전국 9개 도시에서 유통되고 있는 인삼과 도라지에 대하여 전체 112점의 시료를 수거하여 잔류농약을 분석하였다. 122 종의 농약에 대해 GC-ECD, GC-NPD 및 HPLC-UVD를 이용한 다종농약 다성분 분석법으로 잔류농약을 분석하였고, 분석 결과 12점의 시료에서 7종의 농약이 검출되어 10.7% 검출률을 보였다. 농약 성분별 검출 빈도는 procymidone, kresoxim-methyl, endosulfan, cypermethrin, tralomethrin, tetraconazole, chlorfluazuron 순이었다. 농약 이 검출된 시료 중 잔류허용기준을 초과한 시료는 2점으 로 1.8% 검출률을 보였으며, 도라지 1점에서 tetraconazole, 인삼 1점에서 cypermethrin이 검출되었다. 해당 작물에 대한 잔류허용기준이 설정되어 있지 않거나 품목고시 되어 있지 않은 시료는 10점에서 5종의 농약이 검출되어 8.9% 검출률을 보였다. 본 연구에서 검출된 농약이 해당 약용 식물의 섭취로 인체에 유입될 일일섭취허용량 대비 일일 섭취추정량은 최저 0.006%에서 최고 0.333%로 낮은 %ADI 값을 보여 인체 위해도는 낮은 것으로 판단되었다.
        4,000원
        29.
        2012.10 구독 인증기관·개인회원 무료
        A growing interest in ecotoxicological study is on the development of tools and technical resources to assess or determine the effects of a variety of stresses on ecosystems. As many chemicals are synthesized and used for the various purposes, it is inevitable circumstance for organisms to meet the stressors in the environment. Thus, it is important for us to understand the impacts of the stressors to organisms and is essential to equip with a fast detecting system to predict of their behaviors. The high throughput technology using proteomic and metabolomic techniques has been introduced to satisfy such requirements to study the potential adverse effects of some chemicals. Ecotoxicproteomics and Ecotoxicometabolomics are discussed in this talk in terms of their possible role in ecotoxicological studies.
        30.
        2011.10 구독 인증기관·개인회원 무료
        Proteomics may help to detect subtle pollution-related changes, such as responses to mixture pollution at low concentrations, where clear signs of toxicity are absent. Also proteomics provide potential in the discovery of new sensitive biomarkers for environmental pollution. We utilized SELDI-TOF MS (surface enhanced laser desorption. / ionization time-of-flight mass spectrometry) to analyze the proteomic profile of Heterocypris incongruens exposed to several heavy metals (lead, mercury, copper, cadmium and chromium) and pesticides (emamectin benzoate, endosulfan, cypermethrin, mancozeb and paraquat dichloride). Several highly significant biomarkers were selected to make a model of classification analysis. data sets obtained from H. incongruens exposed to pollutants were investigated for differential protein expression by SELDI-TOF MS and decision tree classification. Decision tree model was developed with training set, and then validated with test set from profiling data of H. incongruens. Machine learning techniques provide a promising approach to process the information from mass spectrometry data. Even thought the identification of protein would be ideal, class discrimination does not need it. In the future, this decision tree model would be validated with various levels of pollutants to apply field samples.
        31.
        2017.12 KCI 등재 서비스 종료(열람 제한)
        This study was performed to evaluate the possibility of application of lactic acid bacteria fermentation to increase the anti-allergic activity of the extracts from Houttuynia cordata Thunb. H. cordata Thunb was fermented on 25, 30, 35 and 40℃ for 5 days by two species of lactic acid bacteria, Leuconostoc mesenteroides 4395 and Lactobacillus sakei 383. The anti-allergic activity of water extracts of H. cordata Thunb was then analyzed both before and after fermentation. Anti-allergic activity was determined in vitro assays by using 5-lipoxygenase (5-LO), cyclooxygenase-2 (COX-2) and β-hexoseaminidase release of RBL-2H3 cells (degranulation marker). The extracts fermented at 35℃ by both bacteria had the highest inhibitory activities against 5-LO, and also higher than the control, and the one fermented at 30℃ by both bacteria had the highest inhibitory activity against COX-2. The degranulation of RBL-2H3 cells induced by IgE-antigen complex was estimated as β-hexoseaminidase release rate as reference of 100%, the release rates were inhibited in 25 μg/ml of the extracts fermented at 30, 35 and 40℃ only by L. mesenteroides 4395. These results indicate that anti-allergic activity of H. cordata Thunb is increased by lactic acid bacteria fermentation.
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