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        검색결과 462

        121.
        2014.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The objective of this study was to determine the breed differences in the 3'-untranslated region (UTR) of MC1R mRNA, which may be used to distinguish Korean brindle cattle (Chikso) from other breeds. We investigated the relationship between the variation of 3'-UTR of the MC1R mRNA and coat color among different breeds and the Korean brindle cattle with different coat colors. MC1R mRNA expression levels were determined in accordance with the coat color and hair colors of the tail. Total cellular RNA was extracted from the hair follicles of the tails in Hanwoo, Korean brindle cattle, Holstein and HanwooxHolstein crossbred cattle. After cDNA synthesis, PCR was performed. Sequences of the 3'-UTR of MC1R mRNA were analyzed. The 3'-UTR of the MC1R mRNA from different breeds of cattle did not show any variations. There were no variations in the 3'-UTR of the MC1R mRNA in Korean brindle cattle with different coat colors. The levels of MC1R mRNA expression in hair follicles of the tail varied substantially among the Korean brindle cattle with different coat colors, except yellow coat color. Correlation between the MC1R mRNA expression in the hair follicles of the tail and coat color may be present in the Korean brindle cattle, but not between the variations of 3'-UTR of MC1R mRNA and coat color. Further studies to determine the regulation of MC1R mRNA expression from the hair follicles of different coat colors will be beneficial in clarifying the role of MC1R in the coat colors of the Korean brindle cattle.
        4,000원
        122.
        2014.06 구독 인증기관 무료, 개인회원 유료
        The current study was conducted to evaluate the biocompatibility of α-1,3 galactosyltransferase knockout pig bone graft in a rat calvarial defect model. Porcine cancellous bones were harvested from general and alpha-gal KO pigs and washed with 70% ethanol solution and normal saline. Bone pieces of the alpha-gal KO pig underwent a chemical treatment process to delipidize and deproteinize the bone. Bone graft particles were freeze-dried and stored at −70°C until use. Each bone graft was implanted into the rat calvarial defect in a fresh general pig, fresh transgenic pig, and chemical-treated pig bone group. There was no systemic adverse effect on hematology or necropsy findings in all groups at 1 week and 4 weeks. In the microcomputed tomography analysis, bone volume increased significantly in the chemical-treated transgenic pig bone group, whereas bone mineral density decreased significantly in the fresh general pig bone group compared with other groups. Histological evaluation showed cellular infiltration located at the margin of the bone graft particles, especially in the fresh general pig bone group. These results indicate that fresh general pig bone can elicit a greater local inflammatory response than fresh transgenic pig bone. Further, chemical-treated transgenic pig bone graft was less immunogenic than fresh bone graft. In conclusion, transgenic pig bone is a more biocompatible graft material. In addition, chemical treatment can reduce bone graft immunogenicity by delipidizing and deproteinizing bone.
        4,000원
        123.
        2013.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        이 연구는 3-(1,8나프탈이미도)프로필메타아크릴레이트(NIPM)와 GMA공중합체의 합성과 물성에 관한 과제로서 나프탈이미드 발색단을 가진 공중합체의 조성, 모노머 반응성비, 공명효과(Q)와 극성효과 (e), 형광특성 등을 조사하였다. Azobisisobutyronitronitryl(AIBN) 개시제와 dimethylformamide(DMF) 용매를 60℃에서 공중합하였다. Fineman-Ross(F-R)와 Kelen-Tṻdṏs(K-T)법으로 부터 단량체 반응성비를 구하였으며, r₁값이 r₂보다 크게 나타났다. NIPM이 공중합체내에서 GMA보다 더 많음을 알 수 있다. 380 nm에서 약한 분자 형광띠와 460 nm에서 강한 중합체 엑시머 형광띠가 나타났다.
        4,000원
        124.
        2013.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Lanthanum/gadolinium zirconate coatings are deposited via suspension plasma spray with suspensions fabricated by a planetary mill and compared with hot-pressed samples via solid-state reaction. With increase in processing time of the planetary mill, the mean size and BET surface area change rapidly in the case of lanthanum oxide powder. By using suspensions of planetary-milled mixture between lanthanum or gadolinium oxide and nano zirconia, dense thick coatings with fully-developed pyrochlore phases are obtained. The possibilities of these SPS-prepared coatings for TBC application are also discussed.
        4,000원
        126.
        2013.09 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Two types of Tb- and Na-substituted green phosphors Ca(1-1.5x)WO4: and Ca(1-2x)WO4: weresynthesized with various x values, using a solid-state reaction. The former phosphors contained both substitutional and vacancypoint defects, while the later had only substitutional defects. X-ray diffraction results showed that the main diffraction peak,(112), was centered at 2θ=28.72o and indicated that there was no basic structural deformation caused by substitutions orvacancies. The photoluminescence emission and photoluminescence excitation spectra revealed the optical properties of trivalentterbium ions, Tb3+. Typical transitions, 5D3→7F6, 7F5, 7F4 and 5D4→7F6, 7F5, 7F4, 7F3, and cross relaxations were observed.Subtle differences in the photoluminescence of green phosphors were observed as a result of the point defects. The FT-IRspectra indicated that some of the ungerade vibrational modes had shifted positions and changed shapes, spreading out overa wide range of frequencies. This change can be attributed to the different masses of Tb3+ and Na+ ions and VCa" vacanciescompared to Ca2+ ions. The gerade normal modes of the Raman spectra exhibited subtle differences resulting from point defectsin Ca(1-1.5x)TbxWO4 and Ca(1-2x)TbxNaxWO4.
        4,000원
        127.
        2013.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Xenotransplantation of pig organs into primates results in fatal damage, referred as hyperacute rejection (HAR), and acute humoral xenograft rejection (AHXR), to the organ graft mediated by antibodies pre-existing and newly-producing in primates against their cognate pig antigens. Functional ablation of α1,3-galactosyltransferase (Gal-T KO) of pig which is an enzyme involved in synthesis of Gala1-3Galb1-4GlcNAc-R antigen is essentially required to prevent HAR. Moreover, additional genetic modification under Gal-T KO background for enforced expression of human complement regulatory proteins which can inhibits complement activation is known to effectively imped HAR and AHXR. In this study, we constructed a membrane cofactor protein (MCP) expression cassette under control of human EF1α promoter. This cassette was inserted between homologous recombination regions corresponding to Gal-T locus. Subsequently this vector was introduced into ear skin fibroblasts of female pig by nucleofection. We were able to obtained 40 clones by neomycin selection and 4 clones among them were identified as clones targeted into Gal-T locus of MCP expression cassette by long-range PCR. Real time RT-PCR was shown to down-regulation of Gal-T expression. From these results, we demonstrated human EF1α promoter could induce efficient expression of MCP on cell surface of fibroblasts of female pig.
        4,000원
        128.
        2013.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A major barrier to progress in pig to primate organ transplantation or cell therapy is the presence of terminal α -1,3-galactosyl epitopes on the surface of pig cells. Therefore, the purpose of this experiment was to establish and cha- racterize mesenchymal stromal/stem cells (MSCs) derived from α-1,3-galactosyltransferase (GalT) knock out (GalT KO) pig to confirm their potential for cell therapy. Bone marrow (BM)-MSCs from GalT KO pig of 1 month old were isolated by Ficoll-Paque PLUS gradient and cultured with A-DMEM + 10% FBS on plastic dishes in 5% CO2 incubator at 38.5. GalT KO BM-MSCs were analyzed for the expression of CD markers (CD45-, 29+, 90+ and 105+) and in vitro differentiation ability (adiopogenesis and osteogenesis). Further, cell proliferation capacity and cell aging of GalT KO BM-MSCs were compared to Wild BM-MSCs by BrdU incorporation assay (Roche, Germany) using ELISA at intervals of two days for 7 days. Finally, the cell size was also evaluated in GalT KO and Wild BM-MSCs. Statistical analysis was performed by T-test (P<0.05). GalT KO BM-MSCs showed fibroblast-like cell morphology on plastic culture dish at passage 1 and exhibited CD45-, 29+, 90+ and 105+ expression profile. Follow in ginduction in StemPro adipogenesis and osteogenesis media for 3 weeks, GalT KO BM-MSCs were differentiated into adipocytes, as demonstrated by Oilred Ostaining of lipid vacuoles and osteocytes, as confirmed by Alizarinred Sstaining of mineral dispositions, respectively. BrdU incorporation assay showed a significant decrease in cell proliferation capacity of GalT KO BM-MSCs compared to Wild BM-MSCs from 3 day, when they were seeded at 1×103 cells/well in 96-well plate. Passage 3 GalT KO and Wild BM-MSCs at 80% confluence in culture dish were allowed to form single cells to calculate cell size. The results showed that GalT KO BM-MSCs (15.0 ± 0.4 μm) had a little larger cell size than Wild BM-MSCs (13.5 ± 0.3 μm). From the above findings, it is summarized that GalT KO BM-MSCs possessed similar biological properties with Wild BM-MSCs, but exhibited a weak cell proliferation ability and resistance to cell aging. Therefore, GalT KO BM-MSCs might form a good source for cell therapy after due consideration to low proliferation potency in vitro.
        4,000원
        129.
        2013.09 구독 인증기관 무료, 개인회원 유료
        Xylitol is a sugar alcohol with a variety of functions including bactericidal and anticariogenic effects. However, the cellular mechanisms underlying the role of xylitol in bone metabolism are not yet clarified. In our present study, we exploited the physiological role of xylitol on osteoclast dif-ferentiation in a co-culture system of osteoblastic and RAW 264.7 cells. Xylitol treatment of these co-cultures reduced the number of tartrate-resistant acid phosphatase (TRAP)- positive multinucleated cells induced by 10 nM 1α,25(OH)2 D3 in a dose‐dependent manner. A cell viability test revea-led no marked cellular damage by up to 100 mM of xylitol. Exposure of osteoblastic cells to xylitol decreased RANKL, but not OPG, mRNA expression in the presence of 10-8 M 1α,25(OH)2D3 in a dose‐dependent manner. Furthermore, bone resorption activity, assessed on bone slices in the co- culture system, was found to be dramatically decreased with increasing xylitol concentrations. RANKL and OPG proteins were assayed by ELISA and the soluble RANKL (sRANKL) concentration was decreased with an increased xylitol con-centration. In contrast, OPG was unaltered by any xylitol con-centration in this assay. These results indicate that xylitol inhibits 1α,25(OH)2D3-induced osteoclastogenesis by reducing the sRANKL/OPG expression ratio in osteoblastic cells.
        4,000원
        130.
        2013.08 구독 인증기관·개인회원 무료
        This is one of papers about Chinese character teaching. The questionnaire focused on the teacher’s attentions about Chinese character handwriting teaching, especially on the students’ biases on handwriting studying. Our questionnaire sent to teachers who teach Chinese lesson in 1‐3 grades of primary school in Beijing.  The Excel table show 2500 Chinese characters that must be grasped according to the Chinese curriculum standard (2011). The respondents have been asked state briefly the errors or biases of the strokes or components. Based on the preliminary analysis, the errors mainly happened as adding or losing stroke, choosing wrong component (or radical) similar with the right one, making mistakes on the strokes order. About the artistic element of handwriting, teachers mainly pay attention on the proportional balancing. The questionnaire result could be a reference for the handwriting teaching, and be material for the Chinese handwriting research. The questionnaire also hint us rethink about the appropriateness that direct stroke details written by hard‐tipped pen (pencil, pen, ballpoint pen, etc.) with the rules of soft brush writing characters in print form. 
        131.
        2013.08 구독 인증기관 무료, 개인회원 유료
        The main objective of this work is to perform experimental analyses of a absorption refrigeration system using a new refrigerant-sorbent pair as the working pair. The active component of sorbent is sodium thiocyanate (NaSCN). Ammonia (NH3) is chosen as refrigerant. As a result of these, it is concluded that the unit exhibits good cooling performance and the average cooling capacity is approximately 28.8kW and the average coefficient of performance (COP) of absorption system is 0.56. The unit is a thermal compressor which uses low-grade waste heat to generate refrigeration (cooling or freezing).
        4,000원
        132.
        2013.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        The structural phase transformations of 0.7Pb(Mg1/3Nb2/3)O3-0.3PbTiO3 (PMN-0.3PT) were studied using high resolution x-ray diffraction (HRXRD) as a function of temperature and electric field. A phase transformational sequence of cubic (C)→tetragonal (T)→rhombohedral (R) phase was observed in zero-field-cooled conditions; and a C→T→monoclinic (Mc)→ monoclinic (MA) phase was observed in the field-cooled conditions. The transformation of T to MA phase was realized through an intermediate Mc phase. The results also represent conclusive and direct evidence of a Mc to MA phase transformation in field-cooled conditions. Beginning from the zero-field-cooled condition, a R→MA→Mc→T phase transformational sequence was found with an increasing electric field at a fixed temperature. Upon removal of the field, the MA phase was stable at room temperature. With increasing the field, the transformation temperature from T to Mc and from Mc to MA phase decreased, and the phase stability ranges of both T and Mc phases increased. Upon removal of the field, the phase transformation from R to MA phase was irreversible, but from MA to Mc was reversible, which means that MA is the dominant phase under the electric field. In the M phase region, the results confirmed that lattice parameters and tilt angles were weakly temperature dependent over the range of investigated temperatures.
        4,000원
        133.
        2013.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        GdBa2Cu3O7-y(Gd123) powders were synthesized by the solid-state reaction method using Gd2O3 (99.9% purity), BaCO3 (99.75%) and CuO (99.9%) powders. The synthesized Gd123 powder and the Gd123 powder with Gd2O3 addition (Gd1.5Ba2Cu3O7-y(Gd1.5)) were used as raw powders for the fabrication of Gd123 bulk superconductors. The Gd123 and Gd1.5 bulk superconductors were fabricated by sintering or a top-seeded melt growth (TSMG) process. The superconducting transition temperature (Tc,onset) of the sintered Gd123 was 93 K and the transition width was as large as 20 K. The Tc,onset of the TSMG processed Gd123 was 82 K and the transition width was also as large as 12 K. The critical current density (Jc) at 77 K and 0 T of the sintered Gd123 and TSMG processed Gd123 were as low as a few hundreds A/cm2. The addition of 0.25 mole Gd2O3 and 1 wt.% CeO2 to Gd123 enhanced the Tc, Jc and magnetic flux density (H) of the TSMG processed Gd123 sample owing to the formation of the superconducting phase with high flux pinning capability. The Tc of the TSMG processed Gd1.5 was 92 K and the transition width was 1 K. The Jcs at 77 K (0 T and 2 T) were 3.2×104 A/cm2 and 2.5×104 A/cm2, respectively. The H at 77 K of the TSMG-processed Gd1.5 was 1.96 kG, which is 54% of the applied magnetic field (3.45 kG).
        4,000원
        134.
        2013.05 구독 인증기관 무료, 개인회원 유료
        This paper aims to design and realize movie reservation system based EJB 3.1 with Enterprise of Standardization. This architecture, such as the EJB, but not heavy, to provide all of the architecture is possible. The lightweight container architecture is most often used in business EJB 3.1 is well-known architecture. Therefore, this research has the N-tier enterprise architecture to solve the advantages and disadvantages developed to support the latest EJB 3.1 architecture based on the design and implementation of a movie reservation system.
        3,000원
        135.
        2013.04 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Activated magnetite (Fe3O4-δ) has the capability of decomposing CO2 proportional to the δ-value at comparativelylow temperature of 300oC. To enhance the CO2 decomposition capability of Fe3O4-δ, (Fe1-xCox)3O4-δ and (Fe1-xMnx)3O4-δ weresynthesized and then reacted with CO2. Fe1-xCoxC2O4·2H2O powders having Fe to Co mixing ratios of 9:1, 8:2, 7:3, 6:4, and5:5 were synthesized by co-precipitation of FeSO4·7H2O and CoSO4·7H2O solutions with a (NH4)2C2O4·H2O solution. The samemethod was used to synthesize Fe1-xMnxC2O4·2H2O powders having Fe to Mn mixing ratios of 9:1, 8:2, 7:3, 6:4, 5:5 with aMnSO4·4H2O solution. The thermal decomposition of synthesized Fe1-xCoxC2O4·2H2O and Fe1-xMnxC2O4·2H2O was analyzedin an Ar atmosphere with TG/DTA. The synthesized powders were heat-treated for 3 hours in an Ar atmosphere at 450oCto produce activated powders of (Fe1-xCox)3O4-δ and (Fe1-xMnx)3O4-δ. The activated powders were reacted with a mixed gas(Ar:85%, CO2:15%) at 300oC for 12 hours. The exhaust gas was analyzed for CO2 with a CO2 gas analyzer. The decom-position of CO2 was estimated by measuring CO2 content in the exhaust gas after the reaction with CO2. For (Fe1-xMnx)3O4-δ,the amount of Mn2+ oxidized to Mn3+ increased as x increased. The δ value and CO2 decomposition efficiency decreased asx increased. When the δ value was below 0.641, CO2 was not decomposed. For (Fe1-xCox)3O4-δ, the δ value and CO2decomposition efficiency increased as x increased. At a δ value of 0.857, an active state was maintained even after 12 hoursof reaction and the amount of decomposed CO2 was 52.844cm3 per 1g of (Fe0.5Co0.5)3O4-δ.
        4,000원
        136.
        2013.03 구독 인증기관 무료, 개인회원 유료
        Receptor activator of NF-κB ligand (RANKL) is an essential cytokine for osteoclast differentiation, activation and survival. T lymphocytes such as T17 cells, a subset of T helper cells that produce IL-17, play an important role in rheumatoid arthritic bone resorption by producing inflammatory cytokines and RANKL. It has not yet been clearly elucidated how T cell activation induces RANKL expression. T cell receptor activation induces the activation of nuclear factor of activated T cell (NFAT) and expression of its target genes. In this study, we examined the role of NFAT in T cell activation- induced RANKL expression. EL-4, a murine T lymphocytic cell line, was used. When T cell activation was induced by phorbol 12-myristate 13-acetate (PMA) and ionomycin, RANKL expression increased in a time-dependent manner. In the presence of cyclosporin, an inhibitor of NFAT activation, this PMA/ionomycin‐induced RANKL expression was blocked. Overexpression of either NFATc1 or NFATc3 induced RANKL expression. Chromatin immunoprecipitation results demonstrated that PMA/ionomycin treatment induced the binding of NFATc1 and NFATc3 to the mouse RANKL gene promoter. These results suggest that NFATc1 and NFATc3 mediates T cell receptor activationinduced RANKL expression in T lymphocytes.
        4,000원
        137.
        2013.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Namsan road are taxis in the engine room fires (07/14/2011 18:05) in the tunnel, and the driver of the vehicle was 100 passenger car and more than 500 evacuated were disasters. Pole road vehicles within the tunnel if there is a fire tunnel fire occurred at a two-way evacuation difficult and rapid evacuation is difficult and mass casualties are concerned, the number of casualties is feared. In this study, by considering the problems and improve the Namsan 1,2,3 Tunnel In case of fire, the best disaster response is to come up with ways.
        4,000원
        138.
        2013.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Microtubule-associated protein 1B (MAP1B), a member of MAP1 family, plays a key role in neuronal development. MAP1B binds to many kinds of proteins directly or indirectly. This study was performed to investigate whether MAP1B interacts with GAPDH in bovine follicles using immunoprecipitation (IP) with Western blot analysis and immunohistochemisty. The mRNA expressions of MAP1B and glyceraldehydes 3-phosphate dehydrogenase (GAPDH) were down-regulated in bovine follicular cystic follicles (FCF). In parallel with the mRNA levels, their protein levels were also down-regulated in FCFs. In addition, MAP1B and GAPDH were co-localized at the cytoplasm of follicles. IP with Western blot analysis showed that MAP1B bound to GAPDH in normal follicles, but their binding was absent in FCFs, suggesting a low level of MAP1B and/or GAPDH expressions in FCFs. Taken together, these results suggest that MAP1B interacted with GAPDH may play a role in bovine follicle development, and that GAPDH does not function always as a loading control in bovine follicles.
        4,000원
        140.
        2012.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Resveratrol (RVT) and epigallocatechin gallate (EGCG) individually inhibit adipogenesis in 3T3-L1 adipocytes. The objective was to examine the possibility of interaction between RVT and EGCG, resulting in enhanced inhibition of adipogenesis in 3T3-L1 adipocytes. Preadipocytes were treated with RVT and EGCG individually at 6.25 or 25μM (RVT6.25 or RVT25) and 12.5 or 50μM (EGCG12.5 or EGCG50) and in combination (RVT6.25 + EGCG12.5 and RVT25 + EGCG50). RVT25 as an individual compound decreased lipid accumulation in 3T3-L1 adipocytes by 24%, and RVT25 + EGCG50 further decreased lipid accumulation by 77%. In addition, exposure of 3T3-L1 adipocytes to RVT6.25 + EGCG12.5 and RVT25 + EGCG50 combinations resulted in an enhanced increase of adiponectin release and inhibition of leptin release. Quantitative analysis revealed that the combination of tested materials (RVT6.25 + EGCG12.5 and RVT25 + EGCG50) decreased the expression levels of C/EBPα, PPARγ2, and aP2. These results indicate that the combined treatments with RVT and EGCG produce synergistic effects on inhibiting adipogenesis in 3T3-L1 adipocytes. The overall results suggested that the combining RVT and EGCG might be more capable of exerting antiobesity effects than each individual compound by itself.
        4,000원