The epigenetic involvement in plant hormone signaling

The biosynthesis and signaling of plant hormones play a critical role in almost all biological processes. It is well-documented that phytohormones cross-talk with each other. Epigenetic mechanisms were suggested to regulate expression of downstream targets in hormone signaling pathways that help implement hormone functions. This new layer of complexities that integrate epigenetic information such as DNA methylation, chromatin remodeling, histone modification, microRNAs and siRNAs with plant hormone signaling and regulations of gene expression, has been gradually revealed. In this short review, the author tries to assemble recent progress to establish a molecular linkage between these two large and momentum research fields and also to help readers digest the literature.     

种植牙周围颌骨的骨重建模拟

研究的目的是通过骨重建模拟来预测种植牙植入后周围颌骨的密度分布情况.基于两种成熟且得到广泛应用的骨重建理论,提出了一种新的模拟骨重建的算法,该算法既包含了"死区效应",同时又是基于自组织控制过程.建立了包含种植体和颌骨在内的二维有限元模型,并用文中提出的算法对种植牙周围骨骼组织的密度分布情况进行了骨重建模拟,同时讨论了...     

混流式转轮的性能预估和增容优化

通过对原型混流式转轮的三维定常湍流计算,找出导致水轮机出力达不到设计要求的原因,根据计算结果对原型转轮提出增容优化改造建议,对改造后的转轮性能进行预估,以验证增容优化改造方案的可行性.流场计算以连续方程和雷诺时均N-S方程为基础,选用标准k-ε两方程湍流模型使方程组封闭,通过贴体坐标下的有限体积法对控制方程进行离散,数值求解采用SIMPLIC算法.计算结果表明,增容优化改造后的水轮机转轮流场分布较为合理,满足电站水力参数的要求,改造方案可行.此方法也可推广到转轮水力设计中.     

Uniform boundedness and eventual Hölder continuity to a cancer invasion model with remodeling of ECM and nonlinear diffusion

This paper is concerned with a class of cancer invasion model with nonlinear diffusion and remodeling of ECM. The primary difficulty that arises here is that due to nonlinear diffusion, the good coupling structure between the diffusion term and haptotactic term is destroyed, rendering the effective methods used in the linear diffusion model no longer applicable. Fortunately, we have found a new effective combination between the diffusion term and the haptotactic term, which allows the diffusion term to dominate the haptotactic term, thus preliminarily improving the regularity of the weak solution. Based on these results, we can prove part of long-time asymptotic behavior of the solution, thereby finally proving the uniform boundedness of the weak solution. Subsequently, by improving the convergence of cancer cells u from $L^p$-norm to $L^{\infty }$-norm, it is also proved that after a long time, the weak solution will eventually be Hölder continuous for some slow diffusion cases.     

Single-molecule tethered particle motion to study protein-DNA interaction

Single-molecule techniques have been demonstrated as powerful tools to investigate individual protein-DNA interactions that are difficult to access by conventional biochemical techniques. These methods are popularly used to obtain valuable and detailed molecular mechanisms of enzyme functions. Currently, we have used single-molecule tethered particle motion to investigate protein-DNA interactions, including homologous recombination, site-specific recombination, DNA package, and the nucleosome remodeling process, and useful information was obtained. Here, we will describe the experimental designs and present the information obtained.