97 resultados para Immune selection
em Chinese Academy of Sciences Institutional Repositories Grid Portal
Resumo:
CpG-containing oligodeoxynucleotides (ODNs) are known to be immunostimulatory in vertebrate systems and can activate both innate and adaptive immune responses. In this report, we described the selection, identification, and analysis of CpG motifs with immunoprotective effects in Japanese flounder. Sixteen CpG ODNs were synthesized and examined for the ability to inhibit bacterial dissemination in Japanese flounder blood. Four ODNs with the strongest inhibitory effects were selected and mixed to form ODNs 4M. In addition, a plasmid, pCN6, was constructed that contains the sequences of the four selected ODNs. When administered into Japanese flounder via intraperitoneal injection, both ODNs 4M and pCN6 could, in dose and time dependent manners, afford short-term protection against the infections of two different bacterial pathogens. Immunological analyses showed that ODNs 4M and, especially, pCN6 activated head kidney macrophages and enhanced serum bactericidal activity via probably the alternative pathway of complement activation. When used as a DNA vaccine to immunize Japanese flounder, pCN6 conferred apparent protections (42.9% and 52.6%, respectively, in terms of relative percent survival) against the challenges of two different fish pathogens at 4-week post-vaccination. Transcriptional analysis showed that vaccination with pCN6 upregulated the expression of the genes encoding NKEF, MHC II alpha, IL-1 beta, Mx, and MHC I alpha. These results demonstrate that ODNs 4M and pCN6 are immunostimulatory in Japanese flounder and can induce short- and long-term nonspecific protections against bacterial infections. (C) 2010 Elsevier Ltd. All rights reserved.
Resumo:
Microsensors and microactuators are vital organs of microelectromechanical systems (MEMS), forming the interfaces between controller and environment. They are usually used for devices ranging in size at sub-millimeter or micrometer level, transforming energy between two or more domains. Presently, most of the materials used in MEMS devices belong to the silicon material system, which is the basis of the integrated circuit industry. However, new techniques are being explored and developed, and the opportunities for MEMS materials selection are getting broader. The present paper tries to apply 'performance index' to select the material best suited to a given application, in the early stage of MEMS design. The selection is based on matching performance characteristics to the requirements. A series of performance indices are given to allow a wide range comparison of materials for several typical sensing and actuating structures, and a rapid identification of candidates for a given task. (C) 2002 Elsevier Science Ltd. All rights reserved.
Resumo:
Singular perturbation theory of two-time-scale expansions was developed in inviscid fluids to investigate patternforming, structure of the single surface standing wave, and its evolution with time in a circular cylindrical vessel subject to a vertical oscillation. A nonlinear slowly varying complex amplitude equation, which involves a cubic nonlinear term, an external excitation and the influence of surface tension, was derived from the potential flow equation. Surface tension was introduced by the boundary condition of the free surface in an ideal and incompressible fluid. The results show that when forced frequency is low, the effect of surface tension on the mode selection of surface waves is not important. However, when the forced frequency is high, the surface tension cannot be neglected. This manifests that the function of surface tension is to cause the free surface to return to its equilibrium configuration. In addition, the effect of surface tension seems to make the theoretical results much closer to experimental results.
Resumo:
The pattern selection of one-dimensional coupled map lattices is studied in this paper. It is shown by spatiotemporal variable separation that there exists a threshold wavelength in pattern selection which possesses wave-like structures in space and periodic chaotic motion in time.