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        검색결과 268

        81.
        2013.12 구독 인증기관 무료, 개인회원 유료
        Referral marketing plays an important role in promoting new products. When it comes to innovative agricultural products, early adopter’s review or recommendation has a more critical impact on follower’s purchase decision making. Hence, understanding of consumer’s characteristics and needs play more important role in success of innovation. More particularly, other researchers pay attention to the role of consumer innovativeness. This study attempts to fill this gap in knowledge between innovative propensity of consumer and her/his intention to generate positive word of mouth about new agricultural products. Furthermore, in this paper, we adopt Vandecasteele and Geunes’ motivated consumer innovativeness model to investigate consumer innovativeness in extrinsic motive and intrinsic motive level, and examine the moderating role of referral efficacy. For empirical verification, survey method is used for data collection. Partial least square (PLS) is adopted to analyze the data. Finally, several theoretical contributions and practical implications are discussed.
        4,200원
        82.
        2013.11 구독 인증기관·개인회원 무료
        We have used bulked segregant analysis to screen the strain-specific DNA marker associated psychrophilic 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 490 bp was amplified with OP-L18 primer from the psychrophilic strain and sequenced. A sequence characterized amplified region (SCAR) marker was designed on the basis of the determined sequence and named as OP-L18-1. The PCR analysis with the OP-L18-1 primer showed that this SCAR marker clearly distinguish the psychrophilic strains from the control strains.
        86.
        2013.09 구독 인증기관 무료, 개인회원 유료
        Transgenic chickens have been spotlighted as an highly potent bioreactor for their fecundity, short generation time, and eggs associated with mass production of protein. In this study, we generated transgenic chickens exhibiting oviduct specific expression of human growth hormone fused to human transferrin for oral administration. Gene of the modified growth hormone located at downstream ovalbumin promoter (∼3.6 kb) was introduced to stage X blastodermal cell employing retrovirus vector system. Several transgenic chickens were successfully generated. However, genomic analyses showed unexpected deletion within the transgene. The modification of the transgene seemed to occur during germ cell formation because the deletion was detected only from the sperm DNA of the G0 founder animal. There was no evidence of deletion in the somatic cell DNA samples of the same chicken. Consequently, same pattern of the deletion was confirmed in both somatic and germ cells of the G1 progeny.
        4,000원
        87.
        2013.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Isotropic pitch fibers were stabilized and carbonized for preparing carbon fibers. To optimize the duration and temperature during the stabilization process, a thermogravimetric analysis was conducted. Stabilized fibers were carbonized at 1000, 1500, and 2000℃ in a furnace under a nitrogen atmosphere. An elemental analysis confirmed that the carbon content increased with an increase in the carbonization temperature. Although short graphitic-like layers were observed with carbon fibers heat-treated at 1500 and 2000℃, Raman spectroscopy and X-ray diffraction revealed no significant effect of the carbonization temperature on the crystalline structure of the carbon fibers, indicating the limit of developing an ordered structure of isotropic pitch-based carbon fibers. The electrical conductivity of the carbonized fiber reached 3.9×10⁴S/m with the carbonization temperature increasing to 2000℃ using a four-point method.
        4,000원
        92.
        2012.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, reduced graphene oxide/polyimide (r-GO/PI) composite films, which showed significant enhancement in their electrical conductivity, were successfully fabricated. GO was prepared from graphite using a modified Hummers method. The GO was used as a nanofiller material for the preparation of r-GO/PI composites by in-situ polymerization. An addition of 20 wt% of GO led to a significant decrease in the volume resistivity of composite films by less than nine orders of magnitude compared to that of pure PI films due to the electrical percolation networks of reduced GO created during imidization within the films. A tensile test indicated that the Young's modulus of the r-GO/PI composite film containing 20 wt% GO increased drastically from 2.3 GPa to 4.4 GPa, which was an improvement of approximately 84% compared to that of pure PI film. In addition, the corresponding tensile strength was found to have decreased only by 12%, from 113 MPa to 99 MPa.
        4,000원
        93.
        2012.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Methanol as a carbon source in chemical vapor deposition (CVD) graphene has an advantage over methane and hydrogen in that we can avoid optimizing an etching reagent condition. Since methanol itself can easily decompose into hydrocarbon and water (an etching reagent) at high temperatures [1], the pressure and the temperature of methanol are the only parameters we have to handle. In this study, synthetic conditions for highly crystalline and large area graphene have been optimized by adjusting pressure and temperature; the effect of each parameter was analyzed systematically by Raman, scanning electron microscope, transmission electron microscope, atomic force microscope, four-point-probe measurement, and UV-Vis. Defect density of graphene, represented by D/G ratio in Raman, decreased with increasing temperature and decreasing pressure; it negatively affected electrical conductivity. From our process and various analyses, methanol CVD growth for graphene has been found to be a safe, cheap, easy, and simple method to produce high quality, large area, and continuous graphene films.
        4,000원
        94.
        2012.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Carbon nanotubes (CNTs) have exceptional mechanical, electrical, and thermal properties compared with those of commercialized high-performance fibers. For use in the form of fabrics that can maintain such properties, individual CNTs should be held together in fibers or made into yarns twisted out of the fibers. Typical methods that are used for such purposes include (a) surfactant-based coagulation spinning, which injects a polymeric binder between CNTs to form fibers; (b) liquid-crystalline spinning, which uses the nature of CNTs to form liquid crystals under certain conditions; (c) direct spinning, which can produce CNT fibers or yarns at the same time as synthesis by introducing a carbon source into a vertical furnace; and (d) forest spinning, which draws and twists CNTs grown vertically on a substrate. However, it is difficult for those CNT fibers to express the excellent properties of individual CNTs as they are. As solutions to this problem, post-treatment processes are under development for improving the production process of CNT fibers or enhancing their properties. This paper discusses the recent methods of fabricating CNT fibers and examines some post-treatment processes for property enhancement and their applications.
        4,600원
        95.
        2012.09 구독 인증기관 무료, 개인회원 유료
        Interferon induced transmembrane protein-1 (Ifitm-1) has been reported to have an important role in primordial germ cell formation, and it has expressed in female reproductive organ. In the present study, Ifitm-1 gene expression was identified in testes and all part of epididymis using western immunoblot and immunohistochemistry. Interestingly, Ifitm-1 expression was observed on the head of spermatozoa. To investigate the role of Ifitm-1 gene expression in behavior of spermatozoa after acrosome reaction, fresh sperm was incubated with calcium ionophore to induce acrosome reaction, whereas the expression of Ifitm-1 was not altered after the acrosome reaction. Then to identify the effect of Ifitm-1 in sperm motility and other seminal parameters, different concentration of Ifitm-1 antibody was incubated with spermatozoa, and seminal parameters were assessed using computer-assisted semen analysis (CASA). Interestingly, motility, progressive, and VAP were increased in the sperm with Ifitm-1 antibody treated compared to rabbit serum, however other parameters such as straightness were not changed. In order to identify the functional significance of Ifitm-1 in fertilization, capacitated spermatozoa were pre-incubated with anti- Ifitm-1 antibody and subsequently examined the ability to adhere to mouse oocytes. However, any defection or alteration in sperm-egg fusion was not found, Ifitm-1 antibody treated or non-treated spermatozoa showed a normal penetration. Although the precise role of Ifitm-1 in sperm motility and following fertilization need to be elucidated, this study suggests that the activation of Ifitm-1 on the sperm may enhance the motility of spermatozoa in mice.
        4,000원
        96.
        2012.06 구독 인증기관·개인회원 무료
        Chicken Insulin-like Growth Factor-1 (cIGF-1), one of the most important hormone for regulating physiological function includes body growth, muscle volume, bone density, chicken cell development and metabolism. In order to find in vitro Knokdown expression of cIGF-1, this study introduced tetracycline inducible RNA interference expression system (TetRNAi system). Tet system can inductively control high expression of extrinsic genes and expression of intrinsic genes. So it has advantages such as minimized physiological side-effects any cell and low cytotoxicity. RNAi system is proving to be a powerful experimental tool for inhibition of gene expression and post-transcriptional mechanism of gene silencing. RNAi is mediated by small interfering RNA (siRNA) consisting of 19- to 23- nucleotide double-stranded RNA duplexes that promote specific endonucleolytic cleavage of mRNA targets through an RNA-induced silencing. Then, this study RNAi-based gene knockdown can be achieved by retroviral-based expression systems. Stable integration of our inducible siRNA vector allowed the production of siRNA on doxycycline induction, followed by specific down regulation of chicken IGF-1 gene. Analyses of Real-time PCR to determine expression of the cIGF-1 gene showed successful from chicken embronic fibroblast (CEF) cells with the reduced rate of an approximately 92%. Our results demonstrate the successful regulation of cIGF-1 knockdown expression in CEF cells and support the application of an tetracycline inducible RNAi expression system in transgenic Mini chicken production. This research was supported by Bio-industry Technology Development Program, Ministry for Food, Agriculture, Forestry and Fisheries, Republic of Korea.
        97.
        2012.05 구독 인증기관·개인회원 무료
        This study was conducted to identify an insect species in Genus Ostrinia (Lepidoptera: Crambidae) that gave serious damage to the red bean, Vigna angularis. The species has ever been described as O. zaguliaevi in the previous presentation (Jung et al., 2010). Because, however, inconsistent information has been recognized for the species, we reviewed characteristics in morphological, molecular and sex pheromone levels, and host-range. Male genitalia had 3-lobed uncus and tibia of midleg showed massive type. The morphology indicated that the species might be one of O. zaguliaevi, O. scapulalis and O. zealis. Partial nucleotide sequences of cytochrome oxidase subunit Ⅰ(COⅠ) and Ⅱ genes were not identical with those of the 3 species in GenBank, respectively. The deduced amino acid sequence of COⅠ was not identical with that of O. zealis. In the 23 analyses that sex pheromones were checked, (Z)-9-tetradecenyl acetate, which was reported in the sex pheromone components of both O. zaguliaevi and O. zealis, was not detected at all. An intensive study in Japan has reported that the feeding habit of O. scapulalis is polyphagous, while that of O. zaguliaevi is monophagous (only in Petasites japonicus) (Ishikawa et al., 1999). After considering all these information, we concluded that it is reasonable to decide that the insect species in the red bean in Korea is O. scapulalis.
        98.
        2011.12 구독 인증기관 무료, 개인회원 유료
        Pneumatosis cystoides intestinalis (PCI) is a rare condition characterized by multiple intramural pockets of gas filled cysts in the intestinal wall. PCI is usually found incidentally on an imaging study. Many different causes of PCI have been suggested, including mechanical, pulmonary, and bacterial causes. Treatment is usually conservative, including oxygen and antibiotic therapy. We report on two cases of PCI, without symptoms, in a 62-year-old male and a 72-year-old male. Computed tomography showed numerous, small, round, and air densities on the sigmoid colon. Colonoscopy showed numerous, variable-sized, sessile polypoid, balloon-like distended, and protruding subepithelial masses covered with normal colonic mucosa on the sigmoid colon. We observed that when the cyst was stuck with a needle, the size of the cyst was reduced and showed a flat termination. Therefore, we made a diagnosis of PCI and report on the case with references.
        4,000원
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