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        검색결과 207

        61.
        2017.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Bryopsis africana and Pyropia kinositae are reported for the first time on the list of Korean marine algal flora based on integrated morphological-molecular study. Bryopsis africana from Korea is recognized with distinct main axes, robust thalli, pinnately and radially branched above, and basally denuded. Phylogenetic analyses revealed that B. africana was placed within a clade of Bryopsis. Bryopsis africana differs from B. corymbosa by 2.7% gene sequence divergence. Pyropia kinositae is characterized by oblong to lanceolate thalli, entire margin, purplish red in color, twice as long as broad cells in transversal section view. Phylogenetic analyses revealed that P. kinositae was placed within a clade of Pyropia. Pyropia kinositae differs from P. tenera by 1.5-1.8%, P. ishigecola by 1.2-1.3%, and P. yezoensis by 1.5-1.8% gene sequence divergence respectively.
        4,000원
        62.
        2017.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Detailed morphological studies and molecular analyses based on plastid-encoded rbcL gene sequences were undertaken on Peyssonnelia species, a poorly known genus from Korea. We report new records for the Korean coast, Peyssonnelia harveyana and P. rumoiana. Peyssonnelia harveyana is chiefly characterized by P. rubra-type anatomy, closely packed perithallial filaments in firm matrix, hypothallial filaments arranged in parallel rows, thalli with appressed margins, hypobasal calcification, and unicellular rhizoids. Peyssonnelia rumoiana is principally characterized by two vegetative features, hypothallial filaments arranged in a polyflabellate layer, and perithallial filaments arising from the whole upper surface of each hypothallial cell (Peyssonnelia rubra-type anatomy). Our rbcL analyses revealed that P. harveynana and P. rumoiana were placed within a clade of Peyssonnelia. We also propose the new combination, Sonderophycus cauliferus comb. nov., for previous Peyssonnelia caulifera. Phylogenetic analyses revealed that our S. cauliferus was placed within a clade of Sonderophycus.
        4,000원
        63.
        2017.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was aimed to evaluate the dose-response the effects of nano-encapsulated conjugated linoleic acids(CLAs) on in vitro ruminal fermentation profiles. A fistulated Holstein cow was used as a donor of rumen fluid. Nano-encapsulated CLAs(LF, 5% of nano-encapsulated CLA-FFA; HF, 10% of nano-encapsulated CLA-FFA; LT, 5% of nano-encapsulated CLA-TG; HT, 10% of nano-encapsulated CLA-TG) were added to the in vitro ruminal fermentation experiment. In the in vitro ruminal incubation test, the total gas production on incubation with nano-encapsulated CLAs was increased significantly according to the incubation time, compared with the control(p<0.05). The tVFA concentrations on addition of LF and HT were significantly higher than that of the control(p<0.05). Thus, nano-encapsulated CLAs might improve the ruminal fermentation characteristics without adverse effects on the incubation process. In addition, the population of Butyrivibrio fibrisolvens which is closely related to ruminal biohydrogenation was increased by adding HT, while decreased by adding LF at 12 h incubation. These results showed that nano-encapsulated CLA-FFA could be applied to enhance CLA levels in ruminants by maintaining the stability of CLA without causing adverse effects on ruminal fermentation profiles considering the optimal dosage.
        4,000원
        64.
        2017.04 구독 인증기관·개인회원 무료
        This study was undertaken to evaluate the quality characteristics and antioxidant characteristics of commercially available mixed grains in Korea. The quality characteristics of mixed grain products studied were the mixing ratio, water binding capacity, water solubility, swelling power, and pasting characteristics. The antioxidant characteristics assessed the total polyphenol, flavonoid contents, DPPH and ABTS radical scavenging activities. The mixing ratio of commercially available mixed grain products consisted of 5~25 kinds of grains, with maximum products containing 15-grain products. The water binding capacity, water solubility, and swelling power in commercially available mixed grain products were 99.83~122.83%, 6.91~39.26% and 7.76~86.92%, respectively. The peak, trough, breakdown, final and setback viscosity were 31.53±20.17 RVU, 25.24±13.22 RVU, 6.29±7.43 RVU, 50.27±25.84 RVU and 18.74±8.68 RVU, respectively. Total polyphenol and flavonoid contents were 817.14~2,524.29 μg GAE/g and 06.36~1,099.09 μg CE/g, respectively. The DPPH and ABTS radical scavenging activities were 31.91~151.70 mg TE/100 g and 28.09~119.92 mg TE/100 g, respectively. Products with high phenol content and radical scavenging activity were found to contain greater proportion of brown rice, colored rice, barley and soybean.
        65.
        2016.11 구독 인증기관·개인회원 무료
        It has been reported that collagen and elastin inhibit skin wrinkle formation. Skin elasticity is closely associated with the formation of wrinkles induced by UV exposure. In this study, we investigated the protective effects Pleurotus ostreatus (P. ostreatus) on UVB irradiation induced wrinkle in hairless mice. We evaluated for their free radical-scavenging activities against 1,1-diphenyl-2-picrylhydrazyl (DPPH), the anti-elastase activities, and for their anti-matrix metalloproteinase-1 (MMP-1) activity in human skin fibroblast cells. In the wrinkle measurement and image analysis of skin replicas, the results showed that P. ostreatus significantly inhibited wrinkle formation caused by chronic UVB irradiation. These results suggest that P. ostreatus has anti-wrinkle activity.
        67.
        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.
        68.
        2016.10 구독 인증기관·개인회원 무료
        The spotted-wing drosophila (SWD), Drosophila suzukii (Diptera: Drosophilidae), is an economically damaging pest that feeds on most thin-skinned fruits. In this study, we sequenced portions of the mitochondrial (mt) COI and ND4 genes from a total of 195 individuals collected mainly from Korea. A total of 139 haplotypes were obtained from the concatenated COI and ND4 sequences. A dataset combining GenBank sequences with our own data identified a total of 94 worldwide COI haplotypes with a maximum sequence divergence of 5.433% (32 bp). A rough estimate of genetic diversity in each country showed higher diversity in ancestral distributional ranges, but the invasion over Asian countries seems to have been substantial because haplotype diversity was only 2.35-3.97-fold lower in the USA, Canada, and Italy than that in the populations ancestral ranges.
        69.
        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
        70.
        2016.01 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Pt@Cu/C core-shell catalysts were successfully prepared by impregnation of a carbon support with copper precursor, followed by transmetallation between platinum and copper. The Pt@Cu/C core-shell catalysts retained a core of copper with a platinum surface. The prepared catalysts were used for hydrogen production through catalytic dehydrogenation of decalin for eventual application to an onboard hydrogen supply system. Pt@Cu/C core-shell catalysts were more efficient at producing hydrogen via decalin dehydrogenation than Pt/C catalysts containing the same amount of platinum. Supported coreshell catalysts utilized platinum highly efficiently, and accordingly, are lower-cost than existing platinum catalysts. The combination of impregnation and transmetallation is a promising approach for preparation of Pt@Cu/C core-shell catalysts.
        4,000원
        71.
        2015.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This review presents current progress in the preparation methods of liquid crystalline nanocarbon materials and the liquid crystalline spinning method for producing nano-carbon fibers. In particular, we focus on the fabrication of liquid crystalline carbon nanotubes by spinning from superacids, and the continuous production of macroscopic fiber from liquid crystalline graphene oxide.
        4,000원
        73.
        2015.10 구독 인증기관·개인회원 무료
        During the last century, the overuse of synthetic chemical insecticides led to problems associated with natural environment such as harmful effects on nontarget organisms and development of resistance. Therefore, the application of insect pathogenic microorganisms including Bacillus thuringiensis (Bt), baculoviruses, and entomopathogenic fungi has been an environmentally favorable methods for insect control. However, their use has been limited by several factors such as narrow host spectrum and slow speed of insecticidal activities. A number of approaches have been taken to overcome these defects of microbial insecticides. A novel recombinant baculovirus, NeuroBactrus, was constructed to develop an improved baculovirus insecticide with additional beneficial properties, such as a higher insecticidal activity and improved recovery, compared to wild-type baculovirus. For the construction of the NeuroBactrus, the Bt cry1-5 crystal protein gene was introduced into the Autographa californica nucleopolyhedrovirus (AcMNPV) genome by fusion of polyhedrin-cry1-5-polyhedrin under the control of the polyhedrin promoter. In the opposite direction, an insect-specific neurotoxin gene, AaIT, from Androctonus australis was introduced under the control of an early promoter from Cotesia plutellae bracovirus by fusion of a partial fragment of orf603. The Polyhedrin-Cry1-5-Polyhedrin fusion protein expressed by the NeuroBactrus was not only occluded into the polyhedra, but also activated by treatment with trypsin, resulting in an approximately 65-kDa active toxin. The NeuroBactrus showed a high level of insecticidal activity against Plutella xylostella larvae and a significant reduction in the median lethal time (LT50) against Spodoptera exigua larvae compared to those of wild-type AcMNPV. Expression of the foreign proteins (Bt toxin and AaIT) was continuously reduced during the serial passage of the NeuroBactrus. These results suggested that the NeuroBactrus could be recovered to wild-type AcMNPV through serial passaging. The cry gene from Bt, encoding the Cry protein, has been recently introduced into crops to generate transgenic plants that are resistant to pest insects. 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 S. exigua and Ostrinia furnacalis were identified. We used site-directed mutagenesis to improve the insecticidal activity of Mod-Cry1Ac, resulted 34 mutant cry genes. These mutant cry genes were expressed, as a polyhedrin fusion form, using a baculovirus expression system. The expressed proteins were 95 kDa and SDS-PAGE analysis of the recombinant polyhedra revealed that expressed Cry proteins was occluded into polyhedra and activated stably to 65 kDa by trypsin. When the insecticidal activities of these mutant Cry proteins against to larvae of P. xylostella, S. exigua and O. furnacalis were assayed, they showed higher or similar insecticidal activity compared to those of Cry1Ac and Cry1C. Especially, Mutant-N16 is considered to have the potential for the efficacious biological insecticide since it showed the highest insecticidal activity.
        74.
        2015.04 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        To improve its textural properties as a support for platinum catalyst, carbon aerogel was chemically activated with KOH as a chemical agent. Carbon-supported platinum catalyst was subsequently prepared using the prepared carbon supports(carbon aerogel(CA), activated carbon aerogel(ACA), and commercial activated carbon(AC)) by an incipient wetness impregnation. The prepared carbon-supported platinum catalysts were applied to decalin dehydrogenation for hydrogen production. Both initial hydrogen evolution rate and total hydrogen evolution amount were increased in the order of Pt/CA < Pt/AC < Pt/ACA. This means that the chemical activation process served to improve the catalytic activity of carbon-supported platinum catalyst in this reaction. The high surface area and the well-developed mesoporous structure of activated carbon aerogel obtained from the activation process facilitated the high dispersion of platinum in the Pt/ACA catalyst. Therefore, it is concluded that the enhanced catalytic activity of Pt/ACA catalyst in decalin dehydrogenation was due to the high platinum surface area that originated from the high dispersion of platinum.
        4,000원
        75.
        2014.10 구독 인증기관·개인회원 무료
        Inhibitor cysteine knot (ICK) peptides exhibit ion channel blocking, insecticidal, and antimicrobial activities, but currently, no functional roles for bee-derived ICK peptides have been identified. In this study, a bee (Apis cerana) ICK peptide (AcICK) that acts as an antifungal peptide and as an insecticidal venom toxin was identified. AcICK contains an ICK fold that is expressed in the epidermis, fat body, or venom gland and is present as a 6.6-kDa peptide in bee venom. Recombinant AcICK peptide (expressed in baculovirus-infected insect cells) bound directly to Beauveria bassiana and Fusarium graminearum, but not to Escherichia coli or Bacillus thuringiensis. Consistent with these findings, AcICK showed antifungal activity, indicating that AcICK acts as an antifungal peptide. Furthermore, AcICK expression is induced in the fat body and epidermis after injection with B. bassiana. These results provide insight into the role of AcICK during the innate immune response following fungal infection. Additionally, we show that AcICK has insecticidal activity. Our results demonstrate a functional role for AcICK in bees: AcICK acts as an antifungal peptide in innate immune reactions in the body and as an insecticidal toxin in venom. The finding that the AcICK peptide functions with different mechanisms of action in the body and in venom highlights the two-pronged strategy that is possible with the bee ICK peptide.
        76.
        2014.06 구독 인증기관·개인회원 무료
        We have used bulked segregant analysis to screen the strain-specific DNA marker associated thermophilic strain of Pleurotus eryngii. Bulked genomic DNAs of Pleurotus eryngii were amplified by randomly amplified polymorphic DNA (RAPD) using OP-A, OP-B, OP-L, OP-P, OP-R and OP-S primers to screen the strain-specific DNA marker. A unique DNA fragment of 550 bp was amplified with OP-S07 primer from the thermophilic strain and sequenced. A sequence characterized amplified region (SCAR) marker was designed on the basis of the determined sequence and named as OP-S07-1. The PCR analysis with the OP-S07-1 primer showed that this SCAR marker clearly distinguish the thermophilic strains from the control strains.
        77.
        2014.04 구독 인증기관·개인회원 무료
        A novel recombinant baculovirus, NeuroBactrus, was constructed to develop an improved baculovirus insecticide with additional beneficial properties, such as a higher insecticidal activity and improved recovery, compared to wild-type baculovirus. For the construction of the NeuroBactrus, the Bacillus thuringiensis cry1-5 crystal protein gene was introduced into the Autographa californica nucleopolyhedrovirus(AcMNPV) genome by fusion of polyhedrin-cry1-5-polyhedrin under the control of the polyhedrin promoter. In the opposite direction, an insect-specific neurotoxin gene, AaIT, from Androctonus australis was introduced under the control of an early promoter from Cotesia plutellae bracovirus by fusion of a partial fragment of orf603. The Polyhedrin-Cry1-5-Polyhedrin fusion protein expressed by the NeuroBactrus was not only occluded into the polyhedra, but it was also activated by treatment with trypsin, resulting in an approximately 65-kDa active toxin. In addition, qPCR revealed that the neurotoxin was expressed from the early phase of infection. The NeuroBactrus showed a high level of insecticidal activity against Plutella xylostella larvae and a significant reduction in the median lethal time(LT50) against Spodoptera exigua larvae compared to those of wild-type AcMNPV. Re-recombinant mutants derived from NeuroBactrus in which AaIT and/or cry1-5 were deleted were generated by serial passages in vitro. Expression of the foreign proteins(Bt toxin and AaIT) was continuously reduced during the serial passage of the NeuroBactrus. Moreover, polyhedra collected from S. exigua larvae infected with the serially passed NeuroBactrus showed insecticidal activity similar to that of wild-type AcMNPV. These results suggested that the NeuroBactrus could be recovered to wild-type AcMNPV through serial passaging.
        79.
        2013.10 구독 인증기관·개인회원 무료
        Insect cuticular melanization is regulated by the prophenoloxidase (proPO)- activating system, which is also involved in the innate immune reaction. Here, we demonstrate how the differentiation of the proPO-activating system is regulated toward a cuticular melanization or innate immunity function in silkworm (Bombyx mori) pupae. Our results indicate that the differential and spatial regulation of key components, such as the proPO-activating factor, tyrosine hydroxylase, and porPOs, primes the proPO-activating system for either cuticular melanization or innate immunity. This dual strategy for cuticular melanization in development and innate immunity upon infection demonstrates a two-pronged defense mechanism that is mediated by the priming of the proPO system.
        80.
        2013.10 구독 인증기관·개인회원 무료
        Insect-derived Kazal-type serine protease inhibitors exhibit thrombin, elastase, plasmin, proteinase K, or subtilisin A inhibition activity, but so far, no functional roles for bee-derived Kazal-type serine protease inhibitors have been identified. In this study, a bee (Apis cerana) venom Kazal-type serine protease inhibitor (AcKTSPI) that acts as a microbial serine protease inhibitor was identified. AcKTSPI contained a single Kazal domain that displayed six conserved cysteine residues and a P1 threonine residue. AcKTSPI was expressed in the venom gland and was present as a 10-kDa peptide in bee venom. Recombinant AcKTSPI Kazal domain (AcKTSPI-Kd) expressed in baculovirus-infected insect cells demonstrated inhibitory activity against subtilisin A (Ki 67.03 nM) and proteinase K (Ki 91.53 nM), but not against α-chymotrypsin or typsin, which implies a role for AcKTSPI as a microbial serine protease inhibitor. However, AcKTSPI-Kd exhibited no detectable inhibitory effects on factor Xa, thrombin, tissue plasminogen activator, or elastase. Additionally, AcKTSPI-Kd bound directly to Bacillus subtilis, B. thuringiensis, Beauveria bassiana, and Fusarium graminearum but not to Escherichia coli. Consistent with these findings, AcKTSPI-Kd showed antibacterial activity against Gram-positive bacteria and antifungal activity against both plant-pathogenic and entomopathogenic fungi. These findings constitute molecular evidence that AcKTSPI acts as an inhibitor of microbial serine proteases. This paper provides a novel view of the antimicrobial functions of a bee venom Kazal-type serine protease inhibitor.
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