998 resultados para b-jet


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目的:探讨HIV-1感染是否影响细胞中UNG2的表达.方法:采用四步法SYBR green Ⅰ实时定量RT-PCR,对HIV-1感染者的T和B淋巴细胞,以及HIV-1感染的C8166细胞核内UNG2 mRNA的表达进行测定.结果:UNG2 mRNA的表达在HIV-1感染者的T细胞和HIV-1感染的C8166细胞中被明显上调,分别是对照的8.76倍和8.14倍,而在HIV-1感染者的B细胞中却没有被上调.结论:HIV-1感染导致的UNG2表达上调,可能通过减少TCR的多样性削弱Th的功能,另一方面可能有利于病毒对UNG2的包装.

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目的:为了探讨植物多糖硫酸酯(’&&()与)*+%$ 结合后,能否诱导,-./+#0 的)*+%$ 暴露出中和抗体的表 位,用它作为灭活疫苗以便诱导产生中和抗体。方法:用’&&( 结合的灭活,-./+#0 作为免疫原,与佐剂混和后,免疫 0(102 3 小鼠,制备出免疫血浆。用41-5( 检测血浆内抗,-./+ 特异性-)6 抗体的滴度,用改良的活细胞染色法中和试验检测 免疫血浆的抗,-./+#0 的中和活性。结果:从与’&&( 结合的,-./+#0 免疫组的动物获得的免疫血浆内抗,-./+ 抗体的滴 度(7 组:+8 # 9 +$" ;: 组:+8 # 9 +$" )比未结合’&&( 的,-./+#0 免疫组(;8 < 9 +$# )高,雌性小鼠的免疫血浆的特异性抗体滴 度比雄性的高& 倍。所有免疫组获得的免疫血浆均没有抗,-./+ 中和活性。结论:’&&( 与)*+%$ 相互作用不能诱导暴露出 )*+%$ 的中和抗体表位,但’&&( 可以增强机体免疫原的抗体反应强度,提示它可以作为免疫增强剂用于疫苗研究。

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An immersed finite element method is presented to compute flows with complex moving boundaries on a fixed Cartesian grid. The viscous, incompressible fluid flow equations are discretized with b-spline basis functions. The two-scale relation for b-splines is used to implement an elegant and efficient technique to satisfy the LBB condition. On non-grid-aligned fluid domains and at moving boundaries, the boundary conditions are enforced with a consistent penalty method as originally proposed by Nitsche. In addition, a special extrapolation technique is employed to prevent the loss of numerical stability in presence of arbitrarily small cut-cells. The versatility and accuracy of the proposed approach is demonstrated by means of convergence studies and comparisons with previous experimental and computational investigations.

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In this study various scalar dissipation rates and their modelling in the context of partially premixed flame are investigated. A DNS dataset of the near field of a turbulent hydrogen lifted jet flame is processed to analyse the mixture fraction and progress variable dissipation rates and their cross dissipation rate at several axial positions. It is found that the classical model for the passive scalar dissipation rate ε{lunate}̃ZZ gives good agreement with the DNS, while models developed based on premixed flames for the reactive scalar dissipation rate ε{lunate}̃cc only qualitatively capture the correct trend. The cross dissipation rate ε{lunate}̃cZ is mostly negative and can be reasonably approximated at downstream positions once ε{lunate}̃ZZ and ε{lunate}̃cc are known, although the sign cannot be determined. This approach gives better results than one employing a constant ratio of turbulent timescale and the scalar covariance c'Z'̃. The statistics of scalar gradients are further examined and lognormal distributions are shown to be very good approximations for the passive scalar and acceptable for the reactive scalar. The correlation between the two gradients increases downstream as the partially premixed flame in the near field evolves ultimately to a diffusion flame in the far field. A bivariate lognormal distribution is tested and found to be a reasonable approximation for the joint PDF of the two scalar gradients. © 2011 The Combustion Institute.

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银额果蝇昆明群体有丝分裂中期核型中存在B染色体, 出现频率为69.1%在已 研究过的来自各个地区的银额果蝇中, 昆明群体的B染色体频率最高。B染色体 数目为1—6条。该群体内单雌系间的B染色体数目不同, 个体间和细胞间的B染色 体数目也不同。在核型中, B染色体最小, 形态稳定, 点状, C-带和G-带呈阳性 。 图版1图2表1参12