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        검색결과 546

        201.
        2016.10 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We present an optical imaging survey of AKARI Deep Field South (ADF-S) using the Korea Microlensing Telescope Network (KMTNet), to find optical counterparts of dusty star-forming galaxies. The ADF-S is a deep far-infrared imaging survey region with AKARI covering around 12 deg2, where the deep optical imaging data are not yet available. By utilizing the wide-field capability of the KMTNet telescopes (∼4 deg2), we obtain optical images in B, R and I bands for three regions. The target depth of images in B, R and I bands is 24 mag (AB) at 5, which enables us to detect most dusty star-forming galaxies discovered by AKARI in the ADF-S. Those optical datasets will be helpful to constrain optical spectral energy distributions as well as to identify rare types of dusty star-forming galaxies such as dustobscured galaxy, sub-millimeter galaxy at high redshift.
        4,000원
        205.
        2016.10 구독 인증기관·개인회원 무료
        Bee venom is a complex mixture of toxic components that induces immediate local inflammatory and allergic responses. However, the presence and role of superoxide dismutase (SOD) in bee venom have not been previously investigated. Here, we provide the first demonstration that bee venom contains Cu,Zn SOD (SOD3), a novel extracellular component that promotes local inflammation. Bee venom SOD3 was shown to be an oxidant, rather than an antioxidant, that induces the inflammation-signaling molecule H2O2 in vivo. H2O2 plays a pathological role by triggering an immediate local inflammatory response. Furthermore, bee venom SOD3 significantly induced the activation of proinflammatory mediators (TNF-α and COX-2) and cytokines (IL-1β and IL-6) via the overproduction of H2O2 in mice. Our data demonstrate that bee venom SOD3 induced H2O2, which drives an immediate local inflammatory response, indicating a novel mechanism underlying bee venom-induced local inflammation.
        206.
        2016.10 구독 인증기관·개인회원 무료
        We investigated pollination and foraging activities of honeybee (Apis mellifera L.) and bumblebee (Bombus terrestris L.) during flowering season of the asian pear (Pyrus pyrifolia N.) under different weather conditions. There was no significant statistical difference about the pollination activities of two species. However, the pollination activities of bumblebee were more active than those of honeybee under low temperature and rainfall period. The activities of honeybee and bumblebee were more influenced by temperature than other factors (i.e. illumination and wind velocity). Honeybee was more sensitive to temperature and illumination than bumblebee. At low temperatures (<20℃) on cloudy days (<30,000 lux) with a certain wind velocity (>4.0 m/s), the pollination activity of the honeybee was lower twice than that of bumblebee.
        207.
        2016.10 구독 인증기관·개인회원 무료
        Varroa destructor is a devastating ectoparasitic mite which attacks Honeybee, Apis mellifera. V. destructor feeds on honeybee hemolymph, and often harbors small RNA viruses such as the deformed wing virus to transmit these viruses in the infested bee hive. To survey the genes of V. destructor, total RNA was subjected to high-throughput transcriptome sequencing to construct in silico cDNA library by using the Illumina HiSeq 2000 platform. Total of 2×107,748,792 paired-end short reads were obtained and quality filtered reads were subjected to Trinity de novo assembler followed by TransDecoder, and CD-HIT program to make a V. destructor reference cDNA library containing 28,023 of clustered contigs with protein coding capacity. These cDNA sequences will help us to understand the molecular biology of V. destructor.
        208.
        2016.10 구독 인증기관·개인회원 무료
        The small brown planthopper (SBPH), Laodelphax striatellus, is one of the most serious pest insects of rice plants because it can transmit the rice stripe virus (RSV) which often causes significant reduction of yield in the field. Buprofezine is an effective insect growth regular (IGR) pesticide to control planthoppers, however, since the use of buprofezine for more than a decade, it has caused a certain resistance of SBPH. To survey the responses of SBPH to buprofezine, we exposed 4th instar SBPH to 200 ppm buprofezine by dipping method, and extracted total RNA for RNA-seq by Illumina platform. The quality filtered raw reads of cDNA obtained from experimental and control SBPH were subjected to Bowtie2 followed by eXpress computer program to compare the differential gene expression which will be important information for pest control methods using RNAi.
        209.
        2016.10 구독 인증기관·개인회원 무료
        Insect growth regulators (IGRs) are attractive pest control agents due to their high target specificity and relative safety to the environment. Recently, plants have been shown to synthesize IGRs that affect the insect juvenile hormone (JH) as a part of their defense mechanisms. We identified several JH agonists (JHAs) and antagonists (JHANs) from plant essential oil compounds using a yeast two-hybrid system transformed with the Aedes aegypti JH receptor as a reporter system. They showed high mosquitocidal activities with relatively low LC50 values and caused retardation of ovarian development in female mosquitoes. While the JHAs increased the expression of JH-induced gene, the JHANs caused reduction in the expression of the same gene. The compounds identified in this study could provide insights on the plant-insect interactions and may be useful for the development of novel IGR insecticides.
        210.
        2016.10 구독 인증기관·개인회원 무료
        Bacillus thuringiensis (Bt) produces a variety of insecticidal crystal proteins and widely used as one of the most successful biological control agents. Recently, studies that introduce cry genes into crops to create pest resistance have made much progress, and the total area of land planted with Bt crops has increased substantially. In this study, pest resistance of 8 transgenic Bt rice events with a synthetic cry1Ac gene linked to rice rbcS-tp sequence were assessed under laboratory conditions. Bioassays were performed against Cnaphalocrocis medinalis, which is a significant pest of rice in Asia. C. medinalis larvae were shown to be susceptible to all eight events, even though there were differences between the causes of death. The results differed between developmental stages of the larvae, despite the fact that all 8 events led to high mortalities. These results may be a significant foundation for the evaluation of improved transgenic Bt rice.
        211.
        2016.10 구독 인증기관·개인회원 무료
        Streptomyces is the largest genus of Actinobacteria that forms fungus-like branched networks of hyphae. Streptomyces has been clinically important because they produce various secondary metabolites with antibacterial, antifungal, and nematocidal activities. In order to explore novel insecticidal compounds, extracts from 363 strains of Actinobacteria were screened for their juvenoid and anti-juvenoid activities using yeast-two hybrid system. Among them, extract of Streptomyces spp. showed high anti-juvenoid activity. This extract also showed high level of insecticidal activities against larvae of Aedes albopictus, Laodelphax striatellus, and Ostrinia furnacalis. These results suggested that the secondary metabolites of Streptomyces could be natural sources of novel insecticidal compounds.
        212.
        2016.10 구독 인증기관·개인회원 무료
        Entomopathogenic fungi have been widely studied for their potential as the effective biological control agents. They produce variety of secondary metabolites with insecticidal activities, and it is reasonable to assume that entomopathogenic fungi might produce secondary metabolites modulating juvenile hormone for their survival against defense mechanisms of host insect. In this study, Beauveria spp. and Lecanicillium spp. strains cultured on unpolished rice medium were extracted with acetone. Both extracts showed juvenile hormone antagonist (JHAN) activities in the yeast-two hybrid β-galactosidase assay. In addition, they showed high insecticidal activities against Aedes albopictus, Plutella xylostella, and Ostrinia furnacalis. These results suggested that secondary metabolites of entomopathogenic fungi could be useful for development of novel IGR insecticides.
        213.
        2016.10 구독 인증기관·개인회원 무료
        Insect growth regulators (IGRs) are insecticides that disrupt the normal development of target insects by inducing symptoms such as premature molting or supernumerary larval stages. IGRs are categorized into three types based on their mode of action. One of the them is classified as juvenile hormone agonists (JHAs). In recent studies, we identified juvenile hormone antagonists (JHANs) from plant extracts. In order to identify a novel juvenile hormone agonists and antagonists, we tested 2,354 chemical compounds using the yeast-two hybrid system. Among them, 2 JHAs and 4 JHANs were selected and their insecticidal activities were evaluated against Aedes albopictus larvae. These results may be useful for development of novel IGR insecticides.
        214.
        2016.10 구독 인증기관·개인회원 무료
        Euzophera batangensis (Lepidotera: Pyralidae) is seriously damaging trunks or branches of persimmon tree (Diospyros sp.). We tested the attractiveness of (Z)-9-tetradecen-1-ol (Z9-14OH) and (Z9,E12)-tetradeca- 9,12-dien-1-ol (Z9,E12-14OH) with single or blended baits at southern parts of Korea in 2014 and 2015. The monoene was not attractive at all at three places during the two years. In 2014, diene was equally or more attractive than the mixture in Jinju and Suncheon, respectively. In 2015 too, the attractiveness of diene and mixture was not different in Jinju and Munsan. Monitoring of the seasonal occurrence of E. batangesis with the sex pheromone components revealed that it occurred three times a year; the first occurrence from early April to mid May, the second from early Jun to mid July, and the third from late August to late September.
        215.
        2016.10 구독 인증기관·개인회원 무료
        Chemical pesticides have been used to control persimmon pests, however the overuse of the pesticides caused insect resistance. Herein we investigate the potential of eco-friendly organic pesticides (EFOP) on the control persimmon pests, Stathmopoda masinissa and Riptortus pedestris. Eleven commercially available EFOP were sprayed on the target insects in laboratory conditions. The chemical pesticide, buprofezin+dinotefuran wettable powder served as a positive control. In the bioassay against persimmon fruit moth, the mixture of Chinese scholar tree, goosefoot and subtripinnata extracts (EFOP-2) treatment showed the highest control efficacy: 27.7% (5 days) of survival rates. In the bioassay against bean bugs, the EFOP-2 showed the highest control efficacy: 20.0% (5 days) of survival rates. These results suggest that the mixture of three plants extracts (EFOP-2) has high and multiple potential in the management of the persimmon pests.
        216.
        2016.10 구독 인증기관·개인회원 무료
        Alternative control agents, hopefully overcoming the present issues and problems in agrochemicals, should be considered and finally applied to the vector controls. Entomopathogenic fungi can used as one of the possible novel control agents and great considerations are given to the control of soil- or water-dwelling stages of vectors, such as mosquitoes and ticks. In our research group, the entomopathogenic fungal library has been constructed using the mealworm-based isolation system, which showed a variety of opportunities of their use in vector control. Important key production technologies including granular formulation have been developed to increase their industrialization. Some entomopathogenic fungal isolates showed high biological performance in the control of mosquitoes and ticks in field stands. R&D of down-stream process should be seriously considered as the key step.
        217.
        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
        218.
        2016.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The development of nanostructured functional materials derived from biomass and/or waste is of growing importance for creating sustainable energy-storage systems. In this study, nanoporous carbonaceous materials containing numerous heteroatoms were fabricated from waste coffee grounds using a top-down process via simple heating with KOH. The nanoporous carbon nanosheets exhibited notable material properties such as high specific surface area (1960.1 m2 g–1), numerous redox-active heteroatoms (16.1 at% oxygen, 2.7 at% nitrogen, and 1.6 at% sulfur), and high aspect ratios (>100). These unique properties led to good electrochemical performance as supercapacitor electrodes. A specific capacitance of ~438.5 F g–1 was achieved at a scan rate of 2 mV s–1, and a capacitance of 176 F g–1 was maintained at a fast scan rate of 100 mV s–1. Furthermore, cyclic stability was achieved for over 2000 cycles.
        4,000원
        219.
        2016.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Composite resins are developed as restorative materials to improve esthetics and mechanical properties. To improve the physical properties of resin material, resin filler have to be added. However, no imaging method is adopted for resin filler distribution. Optical coherence tomography (OCT) is a optical imaging technique to delineate microscopic structures within biological tissue. The OCT application to dental composites resin and its filler is not described yet. So, this new and advanced optical method is needed for clinical application for evaluation of dental composite resin. To analyze the spatial distribution of dental composite resin and to evaluate the resin restoration in cavity, frequency domain optical coherence tomography (FD-OCT) was used for their analysis. Resin restored tooth was prepared. For morphological observation, serially sectioned teeth, conventional X-ray taking and micro computed-tomography (CT) images were compared with OCT images. The experiment has done to evaluate the success of the resin restoration using 3 dimensional structure OCT image. In this research, OCT is evaluated as a new technique to image resin restoration. The evaluation of resin restored tooth was performed by OCT. Inappropriate restoration such as marginal adaptation, large porosities, internal integrity and poor contour could be detected. Resin filler also could be checked by OCT. The distribution, number, regularity and size of resin filler can be differentiated from several commercial products. Considering the characteristics of the OCT, it can be used to evaluate the defects of resin restoration, resin filler distribution, and internal integrity between resin material and tooth structure. The OCT can be considered to be a new and advanced method for the evaluation of resin restorations.
        4,000원