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11.
The onset of collagen-induced arthritis in DBA/1 mice is accompanied by a predominantly Th1 response, characterized by production of the proinflammatory cytokines IFN-gamma and TNF-alpha, and a predominance of IgG2a anti-collagen Abs. This study has primarily addressed the effects of continuous administration of exogenous IL-4, a Th2 cytokine, on collagen-induced arthritis in terms of time of onset, clinical symptoms, and histologic changes compared with those in untreated controls. The contributions of Th1 and Th2 cell responses were studied by examining anti-CII IgG subclasses, serum IgE levels, and cytokine production by synovial membrane and lymph node cell cultures. Continuous exposure to IL-4 for 28 days significantly delayed the onset of arthritis from 19 to 37 days and suppressed clinical symptoms. Arthritis occurred approximately 13 to 24 days after treatment ceased. Thereafter, the severity and duration of clinical symptoms were similar to those in control animals, although both joint damage and inflammation at the histologic and cellular levels were less severe than those in untreated controls. During IL-4 treatment, anti-collagen Ab levels were reduced (most significantly those of the IgG2a subclass), histology scores were lower, and the most striking effect was a 1000-fold decrease in TNF-alpha secretion by synovial cells. No significant differences in IgE levels were found between controls and IL-4-treated mice. These data suggest that the anti-inflammatory properties of IL-4 are mediated in part by down-regulation of Th1 responses rather than up-regulation of Th2 responses.  相似文献   
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13.
We have investigated variations in mechanical properties such as tensile strength and specific elongation as well as the variations in electrical properties such as the dielectric loss angle, permitivity and surface resistivity of PVC sheets of various thicknesses exposed during 24 months in weathering and up to 400 h in a Xenotest-1200. Using the test data, an evaluation of the influence of the scale coefficient during ageing was achieved. The test data showed that lower variations in the investigated properties were seen in the case of the thicker sheets. After various ageing periods a correlation between the surface roughness, mechanical and electrical properties could be seen. More important variations could be seen during the ageing period ranging from 50 h to 6 months. Speculations were made about the reasons causing the variations observed in the properties of PVC sheets during ageing.  相似文献   
14.
The legacy wireless systems are designed to exploit static configuration and deployment, and cannot handle the discrepancies of the spatio-temporal traffic demand. Cloud RAN (C-RAN) is a novel flexible radio technology that utilizes the virtualization concepts and can efficiently address the static deployment of conventional wireless systems. The C-RAN also leverages high radio network flexibility by introducing the network function virtualization approach to wireless networks. This paper presents a novel C-RAN platform that virtualizes and operates with full GSM and LTE systems. The presented platform is solely based on open-source and off the shelf solutions, providing easy implementation, low cost and high scalability. The paper also introduces a novel dynamic resource allocation algorithm that facilitates the C-RAN’s optimal performance in dynamic scenarios. The proposed algorithm is analyzed and validated on the presented C-RAN platform. The results of the performance analysis clearly show the advantages of the proposed dynamic resource allocation algorithm. Moreover, they prove the applicability of the C-RAN platform for variety of different scenarios.  相似文献   
15.
The synergistic antioxidant effect of different concentrations (50–250 ppm) of α-tocopherol and myricetin during autoxidation of triacylglycerols of sunflower oil (TGSO) at 100 °C was studied. The process was followed by monitoring the peroxide values and the formation of conjugated dienes. It was established that myricetin is a more effective and stronger antioxidant than α-tocopherol. All mixtures investigated exhibited a synergistic effect. The best synergistic effect was achieved with an equal molar ratio of α-tocopherol and myricetin, and at total concentration of the mixtures lower than 10 × 10−4 M. The kinetic analysis of the results demonstrated that α-tocopherol regenerates myticetin during autoxidation of TGSO at 100 °C.  相似文献   
16.
The paper analyses the evolution of the photovoltaics industry in Australia, Germany and Japan from a comparative policy perspective. It uses a sectoral innovation system framework to discuss the way the three countries have approached the development of knowledge and new technologies, the actors in the sector and the interactions between them, the role of institutions and availability of funding as well as the development of markets for photovoltaics. It outlines the different paths that the countries have adopted for the process of transition from niche to mass production. The findings show that various national players have specialised in different activities, with the institutions' building block being a key determinant for success or otherwise. In the case of Australia, it is also the least developed area which ultimately exposes the country to losing its innovation benefits.  相似文献   
17.
We investigate binary orthogonal arrays by making use of the fact that all possible distance distributions of the arrays under investigation and of related arrays can be computed. We apply certain relations for reducing the number of feasible distance distributions. In some cases this leads to nonexistence results. In particular, we prove that there exist no binary orthogonal arrays with parameters (strength, length, cardinality) = (4, 10, 6 · 24), (4, 11, 6 · 24), (4, 12, 7 · 24), (5, 11, 6 · 25), (5, 12, 6 · 25), and (5, 13, 7 · 25).  相似文献   
18.
This paper presents some of the main technical features and insights of the Kozloduy nuclear power plant (NPP) units 5 and 6 probabilistic safety analysis (PSA) level 1. Probabilistic analyses and their applications in Bulgaria were given further impetus in recent years. More than 17 years after the first PSA study in Bulgaria in 1992 today probabilistic analyses receive increasing attention and application than ever before. The Bulgarian regulatory body (BNRA) is also interested in expanding their capability of reviewing and using PSA in plant safety assessments. In November 2008 within the framework of the program financed by European Union (PHARE), a project for assisting the BNRA in establishing the regulatory requirements on the base of PSA was completed. One of the objectives of this project was performance of the independent review of Kozloduy NPP units 5 and 6 PSA. This review was a new impulse for the authors to present in more details of Kozloduy NPP probabilistic assessment studies in the present paper.  相似文献   
19.
The effect of 11-selenadodecylglyceryl-1-ether (11-SeDGE) at concentrations of 5 × 10−4 and 1 × 10−2 M on the autoxidation of sunflower oil with a natural content of 0.06% tocopherols at 100°C and at room temperature in the dark and of pure triacylglycerols of sunflower oil (TGSO) at 100°C was studied. The process was followed by peroxide concentration (peroxide value) determination and by ultraviolet (UV) spectroscopy. It was found that 11-SeDGE acted synergistically with the tocopherols in sunflower oil in a dose-dependent manner to delay oxidation at 100°C. The results from the UV spectra indicated that 11-SeDGE decomposed the initiators of the process, the hydroperoxides, into inactive products. During oxidation of pure TGSO (i.e, depleted of tocopherols) at 100°C, 11-SeDGE retarded the process without a pronounced induction period. At room temperature, 11-SeDGE showed a slight prooxidative effect on sunflower oil oxidation. Taking into account the established prooxidative effect of the two hydroxy groups in a molecule such as 11-SeDGE, it was recommended to study the lipid autoxidation in the presence of selenium compounds that do not contain such prooxidative groups. Presented at the 91st AOCS Annual Meeting & Expo, San Diego, CA, April 2000  相似文献   
20.
The propagation of stationary solitary waves on an infinite elastic rod on elastic foundation equation is considered. The asymptotic boundary conditions admit the trivial solution along with the solution of type of solitary wave, which is a bifurcation problem.  相似文献   
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