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        검색결과 291

        101.
        2016.10 구독 인증기관·개인회원 무료
        The α-Gal epitope (Galα1,3Galα1,4GlcNAc-R) is responsible for hyperacute rejection (HAR) during transgenic pig-to-non-human primate xenotransplantation. To overcome HAR after xenografts, it is essential for the inactivation of α1,3Galactosyltransferase (GT) gene by the homozygotic knocked out of GT-/- and the isoglobotrihexosylceramide synthase (iGb3s-/-). This study was performed to investigate the generation and characterization of the α1,3GT-MCP/-MCP+iGb3-/- transgenic cells. Ear fibroblast cells from the GT-MCP/-MCP pig were cultured and used to positive control. For iGb3s knock out, the Cas9-GFP-iGb3s vector was transfected into the GT-MCP/-MCP cells. The Cas9-GFP-iGb3s transfected cells were sorted and sequenced for the selection of GT-MCP/-MCP+ iGb3s-/- cells. Among the three sorted cell lines, one transgenic cell line was homozygously deleted 3 bases and 10 bases in each chromosome, respectively. To characterize an expression of α-Gal epitope, a wild type and the transgenic cells were measured by FACS Aria using BS-IB4 lectin antibody. The expression of α-Gal epitope in GT-MCP/-MCP cells (<0.01 %) were significantly down-regulated to the range of wild type (99.4 %) fibroblast cells (p<0.05). To analyze the function of iGb3s, α -Gal epitope expressions were measured for the GT-MCP/-MCP, GT-MCP/-MCP+iGb3s-/+, and GT-MCP/-MCP+iGb3s-/-. The range was 95.8%, 94.2%, and 75.8%, respectively. Interestingly, there was a negative range (16.2%) of α-Gal epitope -/- section in GT-MCP/-MCP+iGb3s-/-, compared to 2.74% of GT-MCP/-MCP+iGb3s-/+ and 1.4% of WT, respectively. Our results demonstrated that iGb3s-/-combined with GT-/- had a function to inhibit α-Gal epitope expression in pig cells. Further studies are needed to evaluate the functions of double gene knock out to minimize a HAR response after xenotransplantation.
        102.
        2016.10 구독 인증기관·개인회원 무료
        The α-Gal epitope (Galα1,3Galα1,4GlcNAc-R) is responsible for hyperacute rejection (HAR) during transgenic pig-to-non-human primate xenotransplantation. There are genes related to the expression of α-Gal epitope such as α1,3Galactosyltransferase gene (GT-/-) and the isoglobotrihexosylceramide synthase (iGb3s-/-). This study was performed to investigate the expression of α-Gal epitope in the skin derived from GT-/- transgenic pig. The skin (7/1000 inches) was obtained by dermatome (Zimmer® Electric Dermatome) from one month old of wildtype (WT) and GT-/- piglets, respectively. The skins were fixed, dehydrated, cleaned, and embedded. To analyze the expression of α-Gal epitope, the paraffin section of WT and GT-/- were stained with BS-IB4 lectin and isoglobotrihexosylceramide synthase antibody. There was a strong BS-IB4 lectin signal in the skin of WT, but not detected in GT-/-. However, the iGb3s positive signals were stained in the skin of both WT and GT-/-. Taken together, it can be postulated that the knocked out of GT gene may not enough to inhibit the expression of α-Gal epitope. Further studies are needed to evaluate the functions of the double knock out of GT and iGb3s on the expression of α-Gal epitope.
        103.
        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
        104.
        2016.06 구독 인증기관·개인회원 무료
        The Korea Mushroom Resource Bank (KMRB) was launched as a national research resource bank in 2015 by the Ministry of Science, ICT and Future Planning. The main goal of the KMRB is to secure important biological resources, mushroom-forming basidiomycota, significant sources of fundamental and novel substances and materials, as dried specimen, cultures, and genomic DNA. For wider application of fungal resources in education, medicinal and industrial uses, the KMRB will undertake following tasks: 1) Survey natural environments across Korea to catalogue mushroom diversity, 2) Establish resource management system based on accurate identification of mushroom, 3) Evaluate the usefulness of the discovered mushroom, 4) Create a secure preservation and loan system. With a global focus on utilizing natural resources, mushroom resources provide excellent opportunities for academic research, and discovering novel substances for use as medicine and energy.
        105.
        2016.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Graphene was grown on molybdenum (Mo) foil by a chemical vapor deposition method at different growth temperatures (1000°C, 1100°C, and 1200°C). The properties of graphene were investigated by X-ray diffraction (XRD), X-ray photoelectron spectroscopy, and Raman spectroscopy. The results showed that the quality of the deposited graphene layer was affected by the growth temperature. XRD results showed the presence of a carbide phase on the Mo surface; the presence of carbide was more intense at 1200°C. Additionally, a higher I2D/IG ratio (0.418) was observed at 1200°C, which implies that there are fewer graphene layers at this temperature. The lowest ID/IG ratio (0.908) for the graphene layers was obtained at 1200°C, suggesting that graphene had fewer defects at this temperature. The size of the graphene domains was also calculated. We found that by increasing the growth temperature, the graphene domain size also increased.
        4,000원
        108.
        2015.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Electrochemical synthesis was employed to prepare a novel hydroxyapatite/graphene (HAP/ Gr) composite powder suitable for medical applications as a hard tissue implant (scaffold). The synthesis was performed in a homogeneous dispersion containing Na2H2EDTA·2H2O, NaH2PO4 and CaCl2 with a Ca/EDTA/PO4 3− concentration ratio of 0.25/0.25/0.15M, along with 0.01 wt% added graphene nanosheets, at a current density of 137 mA cm−2 and pH value of 9.0. The field emission scanning electron microscopy and transmission electron microscopy observations of the composite HAP/Gr powder indicated that nanosized hydroxyapatite particles were uniformly placed in the graphene overlay. Raman spectroscopy, Fourier transform infrared spectroscopy and X-ray diffraction confirmed graphene incorporation in the HAP/Gr powder. The electrochemically prepared HAP/Gr composite powder exhibited slight antibacterial effect against the growth of the bacterial strain Staphylococcus aureus.
        4,000원
        109.
        2015.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Sasa quelpaertensis Nakai is a type of edible bamboo grass distributed on Jeju Island, Korea. S. quelpaertensis has been used as afolk medicine for treatment of a variety of ailments. It has been reported to present biological effects, including anti-inflammatory and antioxidant effects. In this study, we demonstrate that S. quelpaertensis Nakai extract (SNE) rescues immunocytes from gamma radiation-induced apoptosis and oxidative DNA damage. We examined the cytotoxicity, cell proliferation, DNA damage, apoptosis, and generation of reactive oxygen species (ROS) in mice given SNE for 45 days in immune cells. To determine the splenocytes protection capability of SNE, gamma-ray was irradiated to the whole body of C57BL/6 mice. Our results suggest that SNE stimulated the proliferation of splenocytes without cytotoxic effects. In addition, SNE not only decreased DNA damage but also reduced apoptosis of splenocytes, and attenuated the production of ROS generation in hydrogen peroxide-induced splenocytes. Therefore, SNE can protect against gamma radiation-induced damage in mice.
        4,000원
        110.
        2015.11 구독 인증기관·개인회원 무료
        The Korea Mushroom Resource Bank (KMRB) was launched as a national research resource bank in 2015 by the Ministry of Science, ICT and Future Planning. The main goal of the KMRB is to secure important biological resources, mushroom-forming basidiomycota, significant sources of fundamental and novel substances and materials, as dried specimen, cultures, and genomic DNA. For wider application of fungal resources in education, medicinal and industrial uses, the KMRB will undertake following tasks: 1) Survey natural environments across Korea to catalogue mushroom diversity, 2) Establish resource management system based on accurate identification of mushroom, 3) Evaluate the usefulness of the discovered mushroom, 4) Create a secure preservation and loan system. With a global focus on utilizing natural resources, mushroom resources provide excellent opportunities for academic research, and discovering novel substances for use as medicine and energy. PⅣ-2
        111.
        2015.11 구독 인증기관·개인회원 무료
        Medical mushroom, Phellinus linteus and Phellinus baumii called as “Sanghwang” have cultivated in Korea. PL has been studied extensively for its extraordinary capacity of suppressing cancer or enhancing body immunity. The mycelial materials of PL have mainly been used as research samples worldwide because fruiting bodies was difficult to be artificially cultivated. Alternatively, P. baumii (variety, ‘Jangsu’) have been cultivated in Korea. However, fruiting body morphology of P. baumii is clearly different to that of PL. Generally, Phellinus spp. including P. linteus slowly grow on artificial medium such as Potato Dextrose Agar (PDA). In contrast, P. baumii strains were rapidly grown on the artificial media when compared to other Phellinus spp. and thus it was considerable that its mycelial growing ability can be acted as a factor for producing fruiting bodies. This study aimed to find Phellinus isolates having high mycelial growth rate. Five Phellinus isolates that show rapid growth rate on YGM medium were selected from 36 Phellinus isolates collected in Korea. They were identified on nucleotide sequences of rDNA-ITS region. Phellinus linteus strain and Phellinus spp. showing mycelial growth rate comparing to P. baumii were characterized on cultural and bioactive characteristics (antioxidant activity and immune activation).
        113.
        2015.10 구독 인증기관·개인회원 무료
        Bean bug, Riptortus pedestris is an agriculturally serious pest in north eastern Asian countries, damaging to several legumes and fruit trees. Chemical pesticides have been largely used to control the pest but it encounters insecticide-resistance and environmental toxicity issues. Alternatively different mode of action and environmentally sound pest management system can be found in entomopathogenic fungal insecticides. Herein we developed a platform to optimize the fungal production to express their maximum virulence against bean bug, by focusing on solid culture system for thermotolerance, formulation to select effective surfactants to carry the fungal conidia on the cuticles, and relationship between environmental abiotic factors and fungal mortality. First to produce highly thermotolerance fungal conidia, Beauveria bassiana and Metarhizium anisopliae isolates were cultured on several granular cereal substrates, which could be subjected to formulation process. Among the tested media, four media (millet, non-glutinous italian foxtail millet, glutinous italian foxtail millet, brown rice) were superior to the other grains in the spore production and thermotolerance. Next to efficiently deliver the fungal conidia on the cuticles of bean bug, total of six surfactant (CO-2.5, CO-12, LE-7, PE-61, TED-3 and Siloxane) was used to experiment. CO-12 was superior to the other surfactant in mortality of 100 ppm consistence. This work suggests that solid culture system and formulation and application should be seriously considered to reach an optimal level of mortality by inducing their maximum virulence.
        114.
        2015.10 구독 인증기관·개인회원 무료
        Entomopathogenic fungi are facultative microorganisms, dwelling in soil or infecting host insects, and some of the genera have been used as biological control agents worldwide. Collection of fungal isolates should be a platform for the development of highly effective resources, thus in this work we constructed a fungal library using a mealworm pathogenecity-based fungal collection method and further characterized some isolates with high virulence. A phylogenetic three was generated, and of the isolates 17 isolates’ biological features were characterized, such as morphology, spectrum of virulence, cultural characteristics, thermo-stability of fungi, production of biologically active materials, such as enzymes. This work reports an attractive entomopathogenic fungal library including the information of effective isolates in pest management.
        115.
        2015.10 구독 인증기관·개인회원 무료
        The present issue of insect resistance and environmental toxicity of pesticides is triggering deep discussion about the pest management tactics, in which pest monitoring and control activity are mainly involved. Novel control agents, hopefully overcoming the present issues and problems, should be researched and commercially applied to the farm fields. With the monitoring-based research, additionally we have to focus on the control-based, particularly control agent-based research and application. Entomo- pathogenic fungi can used as one of the possible novel control agents once considerations are given to the control of soil- or water-dwelling pests. 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 pest 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 rice weevils, western flower thrips and Japanese bettles in field stands. To elucidate the fungal mode of action, a fungal transformation system using AtMT and gene identification tools were established. Recently a more deep study about the relationship between insect and entomopathogenic fungi is be investigated using RNA seq. We suggest that to make the entomopathogenic fungal products be applied to agricultural farm field, R&D of down-stream process should be seriously considered as the key step.
        116.
        2015.10 구독 인증기관·개인회원 무료
        ocust, Locusta migratoria (Orthoptera: Acrididae) is one of the outbreaking pests worldwide and such big occurrence was recorded in 2014, Korea, however little consideration was given to the management strategy of the pest. Herein we established a indoor locust-rearing system and constructed a locust-pathogenic fungal library to further facilitate the resources to be used as possible biological control agents. A locust colony was provided from the National Institute of Agricultural Science and Technology and reared in corn or barley plants at artificially manipulated rooms. The critical developmental stages, such as oviposition, hatching and mating were successfully proceeded. Entomopathogenic fungal granules were treated to the locust (2 g/rearing box), and in 5~7 days mycosis was observed in the membranous cuticles of head, abdomen and legs. In particular JEF-003 (Metarhizium anisopliae), JEF-186 (M. lepidiotae) and JEF-187 (Clonostachys rogersoniana) showed high virulence against the locust. A population of locust was exposed to the entomopathogenic fungal conidia-incorporated soil to investigate the possibility of the fungal isolation from natural soil, which resulted in the pathogenesis in 7~10 days in laboratory conditions. More than 80% of control efficacy was observed in the greenhouse trial of fungal granular application. This work suggests that locust rearing system was successfully established and entomopathogenic fungi can be used to control the migratory locust.
        117.
        2015.10 구독 인증기관·개인회원 무료
        Bean bug, Riptortus pedestris is an agriculturally serious pest in East Asian countries, reducing the value of crop quality and loss of income in agribusiness. Chemical pesticides have contributed to the management of the pest, but nowadays insect resistance limits the use of chemical pesticides, thus alternatively new pesticides with different mode of actions such as entomopathogenic fungi are considered. Beauveria bassiana and Metarhizium anisopliae JEF isolates were collected, identified and assayed against bean bugs in laboratory conditions. Some isolates showed >80% virulence by spray and contact-exposure methods. Supernatant showed different level of enzyme activity including chitinase, Pr1 protease and lipase. The Agrobacterium tumefaciens-mediated transformation generated random transformants and some mutants had reduced virulence. TAIL-PCR of the random transformants revealed virulence-related genes. This work can be a strong platform for the functional genetics of bean bug-pathogenic B. bassiana.
        118.
        2015.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A large-scale neutral hydrogen (H i) ring serendipitously found in the Leo I galaxy group is 200 kpc in diameter with MHi ~ 1:67 X 109M⊙, unique in size in the Local Universe. It is still under debate where this Hi ring originated - whether it has formed out of the gas remaining after the formation of a galaxy group (primordial origin) or been stripped during galaxy-galaxy interactions (tidal origin). We are investigating the optical and Hi gas properties of the dwarf galaxies located within the gas ring in order to probe its formation mechanism. In this work, we present the photometric properties of the dwarfs inside the ring using the CFHT MegaCam u*, g', r' and i'-band data. We discuss the origin of the gas ring based on the stellar age and metal abundance of dwarf galaxies contained within it.
        3,000원
        119.
        2015.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Carbohydrate derivatives of cyanidin, a class of anthocyanin pigments, are major component of red cabbage, which is responsible for the characteristic reddish color. The color of cyanidin derivatives is quite stable against heat, and here we aimed to identify the chemical component of glucoside-derivatives of cyanidin which is responsible for the thermal stability. By comparing the thermal stability of color from unmodified cyanidin and cyanidin-3,5-diglucoside with the color of cyanidin derivatives from red cabbage, we found that the glucoside modification confers the thermal stability. We believe that our finding will contribute to the preparation of heat-resistant anthocyanin pigments for food coloring and other applications.
        4,000원