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101.
We previously reported the production of recombinant proteins using genetically manipulated chickens and quails. In this study, we constructed a retroviral vector encoding an expression cassette for a fusion protein of the extracellular domain of the human tumor necrosis factor (TNF) receptor 2 and Fc region of human IgG1 (TNFR/Fc), which is expected as an effective drug for inflammatory diseases such as rheumatoid arthritis. The concentrated viral vector was injected into developing chicken embryos. The chickens that hatched stably produced TNFR/Fc in the serum and egg yolk for six months. It appears that the fused protein is transported and accumulated into yolk from the serum, which is mediated by the Fc receptor. The protein purified from the yolk and serum inhibited the cytotoxic activity of TNF-* toward L929 cells, indicating that the protein produced by the chickens is biologically active. These results indicate the effectiveness of the recovery of Fc-fused proteins from the yolk of genetically manipulated chickens.  相似文献   
102.
Local out-of-plane deformation of CFRP ablator subjected to rapid heating   总被引:1,自引:0,他引:1  
This study investigates local out-of-plane deformation of a carbon fiber reinforced phenolic polymer ablator subjected to very rapid heating. Local out-of-plane deformation was measured using a three-dimensional digital image correlation technique at high temperatures. This was achieved by attaching high temperature resistant random patterns on the specimen surface using a ceramic bond. Additionally, blue filters intended for cutting strong infrared radiation from the specimen were also used. This study then discusses the mechanisms of the local out-of-plane deformation under rapid heating conditions in terms of carbonization, pyrolysis gas occurrence, gas pressure storage, and interlaminar debonding due to gas pressure.  相似文献   
103.
An electroless metal plating method was used to form Pt shells on sub-micrometer-sized silica (SiO2) particles fabricated by a sol-gel method. The electroless metal plating method was comprised of three steps: (1) surface-modification of SiO2 particles with polyvinylpyrrolidone (PVP) (SiO2/PVP) or poly-diallyldimethylammonium chloride (PDADMAC) (SiO2/PDADMAC), (2) pre-deposition of Pt nuclei or Pt fine particles on the SiO2 particles by reducing Pt ions in the presence of SiO2/PVP particles (SiO2/PVP-Pt) or SiO2/PDADMAC particles (SiO2/PDADMAC-Pt), and (3) growth of the pre-deposited Pt by immersing the SiO2/PVP-Pt or SiO2/PDADMAC-Pt particles in a Pt-plating solution. The pre-deposition of Pt nanoparticles was successfully performed for the surface-modified SiO2 particles since the surface modification possibly strengthened the affinity between the SiO2 particle surfaces and Pt ions. The Pt nanoparticles were pre-deposited more uniformly in the case of PVP because the pre-deposition took place more slowly for the PVP, which provided uniform surface-modification followed by the uniform pre-deposition of Pt nanoparticles. The formation of Pt shells was successfully performed on the SiO2/PVP-Pt particles in the electroless metal plating process because Pt nuclei were generated by the reduction of H2PtCl6 and then further deposited on the Pt particle surfaces on the SiO2/PVP-Pt particles.  相似文献   
104.
The effect of microtexture on diamond transition was examined for graphite starting materials under shock compressions of 50 to 60 GPa and 80 to 90 GPa. Each of the starting materials used in the present study possessed a fully homogeneous microtexture. To distinguish the effect of microtexture from that of other experimental parameters, the shock conditions were standardized for all specimens tested. Three graphite materials—a glassy carbon, a carbon black, and a natural graphite—were selected and shock compressed using a quenching technique to generate conditions common to all samples. Detailed characterization by transmission electron microscopy and electron energy-loss spectroscopy revealed a clear tendency: The lower the crystallinity and crystallite size of the starting graphite, the more easily the graphite transformed to diamond when the transition mechanism was reconstructive.  相似文献   
105.
A chemosynthetic aliphatic polyester, poly(ethylene succinate) (PESu), was degraded by a poly(3-hydroxybutyrate) (P(3HB)) depolymerase in vitro. While P(3HB) exhibited good biodegradability in all environments, PESu hardly underwent biodegradation in a marine environment. To understand the difference in environmental degradability between PESu and P(3HB), we investigated the distribution of P(3HB)- and PESu-degrading microbes in various environments. PESu-degrading microbes were never detected in marine environments. PESu-degrading bacteria isolated from various environments in this study belonged to the phyla Firmicutes and Proteobacteria. Most PESu-degrading bacterial isolates could not degrade P(3HB), suggesting that PESu was not degraded by P(3HB) depolymerase in actual environments. In addition, all bacterial isolates that were screened for P(3HB) degrading activity from various environments in this study did not degrade PESu, suggesting that PESu does not induce P(3HB) depolymerase in their bacteria and P(3HB)-degrading bacteria are not involved in biodegradation of PESu in actual environments. Taken together, these results could be related with the low biodegradability of PESu in marine environments.  相似文献   
106.
Catalytic properties of supported gallium oxides have been examined for the selective reduction of NO by CH4 in excess oxygen. The activity was greatly affected by the support; Ga2O3/Al2O3 (Al2O3 supported Ga2O3) and Ga2O3–Al2O3 mixed oxide exhibited high activity and selectivity as comparable to Ga-ZSM-5, while unsupported Ga2O3 and the other supported Ga2O3 were ineffective. For Ga2O3/Al2O3, the activity changed with Ga2O3 content, and was highest at about 30 wt% Ga2O3, which corresponds to a theoretical monolayer coverage. Gallium oxide highly dispersed on Al2O3 is considered to be responsible for the high activity and selectivity. The reaction characteristics of Ga2O3/Al2O3 were studied and compared with Ga-ZSM-5 and Co-ZSM-5. Ga2O3/Al2O3 exhibited the highest activity and selectivity at high temperature. In addition, Ga2O3/Al2O3 showed higher tolerance against water than Ga-ZSM-5. C3H8 and C3H6 were also evaluated as reducing agents, and Ga2O3/Al2O3 showed higher activity than Ga-ZSM-5 above 723 K achieving almost complete reduction of NO to N2.  相似文献   
107.
The dielectric characteristics for some cellulose derivatives, namely chlorodeoxycellulose (Cell-Cl; degree of substitution of chlorine, DSCl=0·87), bromodeoxycellulose (Cell-Br; DSBr=0·92) and thiocyanatodeoxycellulose (Cell-SCN; DSSCN=0·88), all substituted only at C-6, together with those of regenerated cellulose, have been investigated in the temperature range -60 to 120°C, and in the frequency range 0·2–100kHz. Only one relaxation process, designated as β, was identified within the frequency and temperature ranges studied. The activation energy of this relaxation increases in the order Cell-Cl<Cell-Br<Cell-SCN, suggesting that the bulkiness of the substituent was the determining factor of the activation energy. The characteristic dielectric parameters, namely polarization magnitude (Δε) and shape parameter (α or β-), were obtained by the analysis of absorption bands and are discussed in relation to the substituent effect. © of SCI.  相似文献   
108.
Endothelial cells acquire different phenotypes to establish functional vascular networks. Vascular endothelial growth factor (VEGF) signaling induces endothelial proliferation, migration, and survival to regulate vascular development, which leads to the construction of a vascular plexuses with a regular morphology. The spatiotemporal localization of angiogenic factors and the extracellular matrix play fundamental roles in ensuring the proper regulation of angiogenesis. This review article highlights how and what kinds of extracellular environmental molecules regulate angiogenesis. Close interactions between the vascular and neural systems involve shared molecular mechanisms to coordinate developmental and regenerative processes. This review article focuses on current knowledge about the roles of angiogenesis in peripheral nerve regeneration and the latest therapeutic strategies for the treatment of peripheral nerve injury.  相似文献   
109.
A giant Seebeck coefficient of ?890 μV/K at 500 °C has been observed in Y0.2Sr0.8TiO3 prepared using nanocubes. Doping rare earth elements, RE, has revealed that small RE is effective to enhance the Seebeck coefficient. Through soft mode observations by Raman spectroscopy and structural calculations based on density functional theory, it has been found that the breakdown of inversion symmetry of the perovskite structure near the surface of nanocubes can be recovered by doping with small RE. Because the dielectric constant is strongly related to the surface structure in this compound, we suggest that RE doping modulates the potential barrier at the grain boundary, resulting in a pronounced energy filtering effect in Y doped SrTiO3.  相似文献   
110.
Cooperative behavior of various agents in dynamic environment   总被引:5,自引:0,他引:5  
The multi-agent model is a model in which agents with limited ability cooperate each other to accomplish a goal. In this paper, we introduce a multi-agent model in which agents are created to imitate real ants. There are two different type of agents, each type of which has a particular task. We designed agents to communicate each other by using pheromone considering noise. On this model, we observed cooperative behavior of agents and evaluated conditions to make an order of behavior in the model.  相似文献   
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