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        검색결과 124

        44.
        2016.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Arsenic (As) is a toxic element that easily taken up by plants root. Several toxic forms of As disrupt plant metabolism by a series of cellular alterations. In this study, we applied annealing control primer (ACP)-based reverse transcriptase PCR (polymerase chain reaction) technique to identify differentially expressed genes (DEGs) in alfalfa roots in response to As stress. Two-week-old alfalfa seedlings were exposed to As treatment for 6 hours. DEGs were screened from As treated samples using the ACP-based technique. A total of six DEGs including heat shock protein, HSP 23, plastocyanin-like domain protein162, thioredoxin H-type 1 protein, protein MKS1, and NAD(P)H dehydrogenase B2 were identified in alfalfa roots under As stress. These genes have putative functions in abiotic stress homeostasis, antioxidant activity, and plant defense. These identified genes would be useful to increase As tolerance in alfalfa plants.
        4,000원
        45.
        2015.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        경기도 8개 지역에서 2010년부터 2012년 동안 식균성인 노랑무당벌레의 발생기주를 조사한 결과, 흰가루병에 감염된 12종의 식물에서 관찰 이 되었다. 특히 가장 밀도가 높았던 배과원에서 노랑무당벌레는 7월 상순부터 11월 상순까지 발견되었다. 식균성인 노랑무당벌레의 장내에서는 흰가루병 균사나 포자 외에 다른 먹이의 흔적이 발견되지 않았고, 알과 번데기를 제외한 전 발육단계에서 균을 섭식하는 특성을 볼 때 절대적 식균성 곤충으로 생각된다. 25℃에서 오이 흰가루병균을 섭식한 노랑무당벌레의 발육기간은 알, 유충, 번데기, 성충이 각각 3.9, 10.4, 4.1, 37.7일 이었고, 발육단계별 오이 흰가루병 섭식량은 45.6, 144.4, 372.2, 628.1, 473.7 mm 2로 4령, 성충, 3령, 2령, 1령 순으로 많았다. 본 연구를 통해 노랑무당벌 레의 오이 흰가루병에 대한 섭식능력을 바탕으로 향후 유용 토착천적으로써 대량사육기술, 저독성 약제 선발 등 작물 흰가루병 종합방제기술(IPM) 에 대한 연구가 필요하리라 사료된다.
        4,000원
        46.
        2014.12 구독 인증기관 무료, 개인회원 유료
        Skin is the outermost organ and acts as a barrier between the organism and environment. Skin protects the organism from environmental insults, such as chemicals, pathogens, and UV light. Much of the protective function of skin is dependent on the epidermis, a multi-layered epithelium that is composed of various cell types such as keratinocytes and melanocytes. Keratinocytes produce protective components through a sophisticated differentiation process. Disturbance of keratinocyte differentiation is related to several skin diseases such as psoriasis and atopic dermatitis. In this study, we prepared extract of combined medicinal plants (ECMP) consisting of Taraxacum platycarpum H. Dahlstedt, Heartleaf Houttuynia, Glycyrrhiza uralensis Fischer, and root bark of Ulmus davidiana. We demonstrated that ECMP enhanced keratinocyte differentiation and barrier functionality using an in vitro cell culture system and in vivo animal test. Treatment of cultured keratinocytes with ECMP resulted in induction of keratinocyte differentiation, as evidenced by increased differentiation markers such as involucrin, loricrin, and filaggrin. In line with these results, ECMP decreased proliferation of keratinocytes cultured in vitro. ECMP applied topically to tape-stripped mouse skins accelerated reduction of transepidermal water loss (TEWL), indicating fast recovery of barrier function. Immunohistochemistry showed that ECMP increased the filaggrin level in tape-stripped mouse skins. These results suggest that ECMP may be applicable for keratinocyte differentiation-related skin diseases.
        4,000원
        47.
        2014.10 구독 인증기관·개인회원 무료
        Biological properties of antimicrobial peptides (AMPs) of hemimetabolous insect are poorly characterized in innate immunity field. To investigate the biochemical properties of hemimetabolous insect’s AMPs, we purified the pyrrhocoricin-like AMP from the hemolymph of Riptortus pedestris and then named as riptocin. We successfully determined the primary protein structure and its cDNA sequence. Interestingly, the determined cDNA revealed that riptocin precursor is composed of 12 repeating units of active riptocins, which implied that riptocin precursor might require to be processed to generate active riptocins by several unidentified processing enzymes. In order to characterize the bio-processing mechanisms of riptocin precursor, we generated the antibody against active riptocin. Using quantitative PCR and Western blot analyses, we showed that gene of riptocin was started to express from the fatbody after three hours post bacterial infection. To address our hypothesis that active riptocin is generated from riptocin precursor by several processing enzymes, we need to obtain the riptocin precursor. Currently, we are expressing the recombinant riptocin precursor using in vitro translation system. Meanwhile, we investigated whether naive hemolymph (naive HL), which may contain precursor riptocin, can generate active riptocin when riptocin precursor was co-incubation with bacteria-challenged hemolymph (active HL), which may contain all processing enzymes. Actually, when naive HL was incubated with active HL, antimicrobial activity was dramatically increased, suggesting that processing enzymes in active HL may induce processing of riptocin precursor to generate active riptocins.
        48.
        2014.07 구독 인증기관·개인회원 무료
        A choice in temporal discounting is often made on one preferred option between a sooner but smaller reward and a later but larger reward. In temporal discounting, a consumer undergoes an evaluation process concerning the trade-offs between time delay (i.e., a choice between sooner and later receipts) and the amount of reward (i.e., a choice between smaller and larger rewards). It has been evidenced that a surprisingly large number of consumers is inclined to choose a sooner option with a lower economic value. Those consumers tend to apply an excessive temporal discounting rate to the time delay and as a result, the sooner option with lower economic value stands out to be more attractive. However, there is another group of consumers who deliberately promote the long-term perspective in the evaluation process. Those consumers show a high tendency of choosing a later option with greater economic value. A key factor affecting the evaluation process is the sensitivity to time delay a consumer entails. The sensitivity to time delay could systematically affect the representations of hedonic pleasure being projected at different time delays and is the basis of individual differences in hedonic orientation. An anhedonia, a person with the ability to control physical pleasure, is likely to be less sensitive to time delay and apply a lower discounting rate for delayed rewards because he processes the presently available pleasure less intensively than do ordinary consumers. Thus, anhedonic consumers are more likely to choose a delay reward in temporal discounting choices. In a famous fable by Aesop, “The Ant and the Grasshopper” suggest a possible linkage between hedonic orientation and temporal discounting tendency. The story goes that the Grasshopper enjoys whatever is on its hands and does not give much thought to what is going to happen in the future, while the Ant takes on the hardship denying the current pleasure as he plans for the difficult winter time. We conducted an experiment to investigate the relationships among individual differences in hedonic orientation, and the behavioral choices in temporal discounting trials by examining the EEG theta (4-8 Hz) correlates. A hedonic orientation questionnaire was developed using twenty selected items from Physical Anhedonia Scale, Barratt Impulsiveness Scale and Impulsive Buying Scale. Using the questionnaire, the hedonic orientation of fifteen participants was analyzed. Among them, five participants were classified into anhedonia (Ant-like, AN) group and ten participants were into hedonic pleasure dependent (Grasshopper-like, GH) group. Participants conducted ten temporal discounting trials and, in each trial, a choice was made between two options, either a smaller reward today (the “now” option) or a greater reward to be received after a specified time delay (the “future-oriented” option). The absolute theta activations while viewing a future-oriented option in each trial were analyzed as the neural correlates of temporal discounting. The results indicated that the hedonic orientation of participants had a high prediction power of not only behavioral choices in temporal discounting but also EEG theta activations in the frontal brain region. In analyzing temporal discounting tendencies, the discounting rate of AN group was found to be lower than that of GH group. In addition, EEG theta analysis shows two interesting activation patterns in the frontal region. First, AN group showed higher frontal theta activations than GH group indicating its deliberate engagement to future-oriented options. Second, theta activations in the Dorsolateral Prefrontal Cortex (DLPFC), more specifically AF3 and AFz, were negatively correlated with the discounting rate of participants. Neuroscience researches often refer that DLPFC is associated with deliberate and analytic information processing. Therefore, the high theta activations in DLPFC could be considered as a distinctive neural indicator of high anhedonia traits and low temporal impulsivity.
        49.
        2013.10 구독 인증기관·개인회원 무료
        Emergence of resistant two-spotted spider mite (TSSM) can induce the over usage of standard amount of acaricides and result in various side effects. Rapid resistance monitoring is essential step for the efficient management of resistant populations by enabling the selection of appropriate acaricides. Here, we evaluated the 19 acaricides to determine its suitability for residual contact vial bioassay (RCV) by using PyriF strain as a reference. Twelve acaricides (Amitraz Abamectin, Bifenthrin, Bifenazate, Chlorfenapyr, Cyenopyrafen, Cyflumetofen, Endosulfan, Fenothiocarb, Monocrotophos, Omethoate and Tebufenpyrad) revealed the dose-dependent mortality within 8 h, whereas other remaining acaricides (Dicofol, Etoxazole, Fenbutatin oxide, Fenpyroxymate, Flufenoxuron, Spiromesifen and Pyridaben) did not. This finding suggests that the application of RCV method is limited depending on the mode of action and physicochemical properties of each acaricide. Resistance levels to 12 acaricides were determined for four field populations of TSSM by using RCV diagnostic kit. All TSSM populations showed the highest sensitivity to cyflumetofen, indicating that it would be most effective in controling field populations. RCV diagnostic kit would enable to provide crucial information for choosing the most appropriate acaricides in the field.
        51.
        2013.04 구독 인증기관·개인회원 무료
        Bemisia tabaci, sweetpotato whitefly, has been recognized one of the most destructive insect pests worldwide because of increased resistance to some insecticide groups requiring alternative strategies for its control. We conducted a study of the influence of relative humidity, temperature and different developmental stages on the susceptibility of sweetpotato whitefly to conidia of Isaria javanica isolate, which had been reported high virulence against Q biotype of B. tabaci. The mortality of tobacco whitefly was low at low constant relative humidities, but was high when kept high humidity for first 24 hours and transferred to low humidity. The Isaria isolate had wide range of temperature (15℃ to 35℃) to control sweetpotato whitefly. The isolate has virulence to the egg and all developmental stages of nymph of B. tabaci. These results indicated that the isolate had good control effects at various environmental conditions and is an excellent candidate to develop a microbial pesticide to control sweetpotato whitefly.
        52.
        2013.04 구독 인증기관·개인회원 무료
        Emergence of resistant two-spotted spider mite (TSSM) can induce the over usage of standard amount of acaricides and result in various side effects. Rapid resistance monitoring is essential step for the efficient management of resistant populations by enabling the selection of appropriate acaricides. Here, we evaluated the 10 acaricides to determine its suitability on residual contact vial bioassay (RCV) by using PyriF strain as standard. Five acaricides (Abamectin, monocrotophos, tebufenpyrad, bifenazate and cyflumetofen) revealed the dose-dependent mortality within 8 h, whereas other remaining acaricides (Fenbutatin oxide, fenpyroxymate, flufenoxuron, spiromesifen and etoxazole) did not. This finding suggests that the application of RCV method is limited depending on the mode of action and physicochemical properties of each acaricide. Resistance levels to five acaricides (Abamectin, monocrotophos, tebufenpyrad, bifenazate and cyflumetofen) were determined for four field populations of TSSM by using RCV diagnostic kit. All TSSM populations showed the highest sensitivity to cyflumetofen, indicating that it would be most effective in controling field populations. RCV diagnostic kit would enable to provide crucial information for choosing the most appropriate acaricides in the field.
        54.
        2012.06 구독 인증기관 무료, 개인회원 유료
        Iron is an essential trace element for normal functions of the body. Restriction of iron availability directly limits erythropoiesis. The objective of this experiment was to compare the bioavailability of iron nanoparticles (Fe-NPs) with iron-microparticles (Fe-MPs) in anemic mice. There were four experimental groups, including the normal control group, iron-deficiency anemia (IDA) group, Fe-NPs group, and Fe-MPs group. Animals in the normal group fed on an adequate iron-containing diet (45 ppm Fe). Meanwhile, animals in the other three groups fed on a low Fe diet (4.5 ppm Fe) for seven weeks. Double deionized water was supplied as drinking water ad libitum. After feeding for three weeks with the low Fe diet, animals in the Fe-NPs and Fe-MPs groups received oral administration of Fe-NPs or Fe-MPs at a daily dose of 40 mg/kg for four weeks. The IDA group showed markedly decreased red blood cell (RBC) count, hematocrit (Hct), and hemoglobin (Hb) values compared with the normal group throughout the experimental periods. Treatments with Fe-NPs or Fe-MPs for four weeks resulted in restoration of the decreased RBC count and hematological values similar to normal values. The Fe-NPs group showed faster restoration in values than Fe-MPs with passage of time. The iron contents of the upper small intestine in the Fe-NPs and Fe-MPs groups were higher than in the normal group at weeks 2 and 4. Treatment with Fe-NPs and Fe-MPs resulted in a significant increase in hepatic iron contents and lipid peroxidation, compared with the IDA group with passage of time. The iron contents in liver and ferritin deposits in spleen were identified in the Fe-NPs and Fe-MPs groups, similar to the normal group. These results indicate that oral administration of both Fe-NPs and Fe-MPs can result in recovery from anemia and Fe-NPs is more absorbable and available in the body than Fe-MPs.
        4,600원
        55.
        2012.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The effects of different ingredient formulations on physicochemical qualities and consumer preferences were investigated using Baikseolgi incorporated with perilla powder, a healthy food ingredient, as a model system. Perilla powder was incorporated into the formulation at five different amounts (0%, 5%, 10%, 15%, and 20% (w/w)) by replacing equivalent amount of non-glutinous rice flour. After appropriate mixing, rice cakes were steamed and quality attributes were evaluated after cooling. The pH increased but moisture content decreased significantly with an increase in the perilla powder substitution (p < 0.05). Lightness (L*) decreased significantly from 80.32 to 70.73 with the higher incorporation of perilla powder (p < 0.05), indicating that the color of Baikseolgi became dark. Redness (a*) and yellowness (b*); on the other hand, increased significantly (p < 0.05). Hardness decreased significantly as the perilla powder content increased in the formulation (p < 0.05). With respect to overall acceptability, the control received the highest mean score of 5.90; however, this was not significantly different from all samples tested except for 20% sample (p > 0.05). Five percent sample received the highest or competitively high preference scores in all attributes; thus, incorporation of 5% perilla powder in the formulation of Baikseolgi would be recommended while taking advantages of the health benefits of perilla without sacrificing the quality acceptance by the consumers.
        4,000원
        56.
        2011.05 구독 인증기관·개인회원 무료
        Damages by Tyrophagus spp. (Acari: Acaridae) on horticultural crops were newly observed in recent years especially in organic culture greenhouses in Korea. The crops damaged by the mite species were Spinacia oleracea L. (spinach), Cucumis sativus (cucumber), and Phalaenopsis schilleriana (orchid). The spinach inner leaf growth was halted affected by the feeding of Tyrophagus similis at the early stage of the shoot emergence. The young leaves of the spinach bud had small holes and the leaves were deformed as they grew up. The surface of young cucumber fruits became shiny and soft at the early damage stage and the damaged surfaces became corky as the plants grew up. The mite from cucumber was identified as Tyrophagus neiswanderi Johnston & Bruce. In phalaenopsis orchid, the flower buds became yellow and dropped and the lower side of the leaves had white spots. The damages were caused by Tyrophagus putrescentiae.
        57.
        2011.03 구독 인증기관 무료, 개인회원 유료
        The faulty regulation of imprinting gene lead to the abnormal development of reconstructed embryo after nuclear transfer. However, the correlation between the imprinting status of donor cell and preimplantation stage of embryo development is not yet clear. In this study, to determine this correlation, we used the porcine spermatogonial stem cell (pSSC) and fetal fibroblast (pFF) as donor cells. As the results, the isolated cells with laminin matrix selection strongly expressed the GFRα-1 and PLZF genes of SSCs specific markers. The pSSCs were maintained to 12 passages and positive for the pluripotent marker including OCT4, SSEA1 and NANOG. The methylation analysis of H19 DMR of pSSCs revealed that the zinc finger protein binding sites CTCF3 of H19 DMRs displayed an androgenic imprinting pattern (92.7%). Also, to investigate the reprogramming potential of pSSCs as donor cell, we compared the development rate and methylation status of H19 gene between the reconstructed embryos from pFF and pSSC. This result showed no significant differences of the development rate between the pFFs (11.2±0.8%) and SSCs (13.3±1.1%). However, interestingly, while the CTCF3 methylation status of pFF-NT blastocyst was decreased (36.3%), and the CTCF3 methylation status of pSSC-NT blastocyst was maintained. Therefore, this result suggested that the genomic imprinting status of pSSCs is more effective than that of normal somatic cells for the normal development because the maintenance of imprinting pattern is very important in early embryo stage.
        4,000원
        58.
        2010.12 KCI 등재 구독 인증기관·개인회원 무료
        Lentinus lepideus is an edible mushroom, belongs to the family Tricholomaceteae and order Agaricales. The purpose of this study was to evaluate the antioxidant activities, tyrosinase inhibitory effects on the fruiting bodies of L. lepideus extracted with acetone, methanol and hot water. The antioxidant activities were performed on β-carotene-linoleic acid, reducing power, 1,1-diphenyl-2-picrylhydrazyl free radical scavenging, and ferrous chelating abilities. In addition to this, phenolic acid and flavonoids contents were also analyzed. Hot water extract of L. lepideus showed the strongest β-carotene-linoleic acid inhibition as compare to others extracts. At 8 mg/ml, methanolic extract showed a high reducing power of 1.21. The scavenging effects on 1,1-diphenyl-2-picrylhydrazyl radicals, acetonic and methanolic extracts were effective than hot water extract. The strongest chelating effect (87.50%) was obtained from the methanolic extract at 1.0 mg/ml concentration. Antioxidant activities of the extracts from the fruiting bodies of L. lepideus were increased with the increasing concentration. After application of reverse phase high performance liquid chromatography, coupled to a diode array detector and electrospray ionisation mass spectra, six phenolic compounds namely, chlorogenic acid, vanillin, naringin, naringenin, formononetin and biochanin were identified from acetonic extract. Tyrosinase inhibition of acetonic, methanolic, and hot water extracts of L. lepideus were increased with the increasing of concentration. Results revealed that acetonic and methanolic extract showed good, while hot water showed moderate activities of the tyrosinase inhibition at the concentration tested. This study suggests that fruiting bodies of L. lepideus can potentially be used as a readily accessible source of natural antioxidants.
        59.
        2010.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study aims to reveal how EA affects BAX and NF-kB involved in cell deaths from global ischemia, and to do this, observes the changes of BAX and NF-kB caused by EA application after transient global ischemia. The experimental method is to give rise to global ischemia and apply EA to 27 SD rats with the particulars of being six-week-old, male, around-300 gram-weighing, and adapted to laboratory environment for more than a week, and divide them into three groups, that is, GV20 EA group(n=9), L14 EA group(n=9), no-treatment GI group(n=9), and then observe their changes of BAX and NF-kB at the time lapse of 6 hours, 9 hours and 12 hours after ischemia, using western blotting. The numerical decrease of BAX expression at the time lapse of 9 hours after EA application, though not statistically significant, was observed in GV20 EA group and L14 EA group, and the NF-kB expression appeared statistically significant decrease in GV20 EA group and L14 EA group, but the expression was higher in the group with EA application. Therefore, EA application at the early phase of global ischemia is considered to affect BAX and NF-kB and play a positive role in decreasing apoptosis and cell deaths by inflammation.
        4,000원
        60.
        2010.10 구독 인증기관·개인회원 무료
        The first commercial bioinsecticide in Korea was registered in 2003 to control diamond back moth and beet armyworm in Chinese cabbage using Bacillus thuringiensis subsp. aizawai. Currently, fourteen microbial pesticides have registered in Korean market. The Korean government is aiming for 40% reduction (from the 2004 value) in the use of chemical pesticides by 2013. To increase the use of microbial pesticides as an alternative of chemicals, we conducted in vitro bioassay with Bt products. Bt products were treated alone and in combination against larvae of beet armyworm, diamond back moth and tobacco cutworm. Five Bt products shown high mortality against diamond back moth in recommended concentration, but had low control effects against beet armyworm and tobacco cutworm. Mixed Bt products had no synergic effects against the tested three moths. When Bt products were sprayed with higher concentration than recommended dose, those mortality was similar with lower concentration.
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