Mechanism of the interaction between Au nanoparticles and polymerase in nanoparticle PCR

Nanoparticle PCR is a novel method to optimize DNA amplification. It performs well in improving specificity, enhancing sensitivity and speed. Several mechanisms were proposed in previous studies: one was based on the interaction between gold nanoparticles (AuNPs) and DNA while the other was attributed to the heat transfer property of AuNPs. In this paper, we propose that the interaction between AuNPs and DNA polymerase can significantly influence PCR. First, the addition of DNA polymerase can eliminate the inhibitory effects of excess AuNPs. Second, the addition of AuNPs will increase yield of the desired PCR product and make the optimum concentration of DNA polymerase move to higher value. Third, while excess polymerase might inhibit amplification efficiency, AuNPs can reverse this process and the yield of PCR amplification. Based on these results we propose a possible mechanism that AuNPs might modulate the activity of polymerase and improve PCR amplification.     

Review: Actin-based dynamics during spermatogenesis and its significance

Actin can be found in all kinds of eukaryotic cells, maintaining their shapes and motilities, while its dynamics in sperm cells is understood less than their nonmuscle somatic cell counterparts. Spermatogenesis is a complicated process, resulting in the production of mature sperm from primordial germ cell. Significant structural and biochemical changes take place in the seminiferous epithelium of the adult testis during spermatogenesis. It was proved that all mammalian sperm contain actin, and that F-actin may play an important role during spermatogenesis, especially in nuclear shaping. Recently a new model for sperm head elongation based on the acrosome-acroplaxome-manchette complex has been proposed. In Drosophila, F-actin assembly is supposed to be very crucial during individualization. In this mini-review, we provide an overview of the structure, function, and regulation characteristics of actin cytoskeleton, and a summary of the current status of research of actin-based structure and movement is also provided, with emphasis on the role of actins in sperm head shaping during spermiogenesis and the cell junction dynamics in the testis. Research of the Sertoli ectoplasmic specialization is in the spotlight, which is a testis-specific actin-based junction very important for the movement of germ cells across the epithelium. Study of the molecular architecture and the regulating mechanism of the Sertoli ectoplasmic specialization has become an intriguing field. All this may lead to a new strategy for male infertility and, at the same time, a novel idea may result in devising much safer contraception with high efficiency. It is hoped that the advances listed in this review would give developmental and morphological researchers a favorable investigating outline and could help to enlarge the view of new strategies and models for actin dynamics during spermatogenesis.     

Effects on Structure and Abrasion Resistance of GCr15 Steel by Surface Gas-Phase RE Diffused Permeation with Laser Melting Solidification

The effects on abrasion resistance and the microstructure of GCr15 steel surface by the compound technology of permeating RE combined with laser melting modification was studied. The results show that after compound treatment, the abrasion resistance of samples has been improved significantly and the weight loss has been reduced to 14% of blank sample; the microstructure has been denser and more uniform than that of untreated; meanwhile, the grain has been refined and the concentration gradients of the elements permeated have been decreased obviously.     

A new estimator of covariance matrix via partial Iwasawa coordinates

This paper is concerned with the problem of improving the estimator of covariance matrix under Stein’s loss. By the partial Iwasawa coordinates of covariance matrix, the corresponding risk can be split into three parts. One can use the information in the weighted matrix of weighted quadratic loss to improve one part of risk. However, this paper indirectly takes advantage of the information in the sample mean and reuses Iwasawa coordinates to improve the rest of risk. It is worth mentioning that the process above can be repeated. Finally, a Monte Carlo simulation study is carried out to verify the theoretical results.     

Ruin probabilities with pairwise quasi-asymptotically independent and dominatedly-varying tailed claims

This paper considers the nonstandard renewal risk model in which a part of surplus is invested into a Black-Scholes market whose price process is modelled by a geometric Brownian motion, claim sizes form a sequence of not necessarily identically distributed and pairwise quasi-asymptotically independent random variables with dominatedly-varying tails.The authors obtain a weakly asymptotic formula for the finite-time and infinite-time ruin probabilities.In particular,if the claims are identically distributed and consistently-varying tailed,then an asymptotic formula is presented.     

区域科技创新系统的多层次治理——苏格兰的经验与启示

多层次区域边界、差别的制度和多元政策主体使区域科技创新治理面临诸多问题和挑战。通过解析苏格兰区域科技创新系统多层次治理模型及运行机制,分析在功能、部门和层次三个维度的框架中政策网络的整合过程,为区域性科技创新治理系统的网络治理及政策制定提供经验借鉴。     

基于VME的通用列车网络控制设备设计方案及实现

分析基于VME总线的通用列车网络控制设备的软、硬件设计方案和关键子卡的实现原理.通过功能板卡的不同配置,既可以配置为具有MVB总线管理功能的车辆控制单元VCU,也可以配置为具有信号采集和输出的远程输入输出单元RIOM.设备具有MVB总线管理功能,支持MVB过程数据、消息数据和监视数据的MVB网络通信,用户利用配套的网络配置监视软件可以对网络设备进行参数配置,实现MVB网络通信的同时,还能对网络上的各类MVB设备进行状态监控,最终该设计在轨道车辆牵引传动实验系统中得到验证.     

Research on Key Techniques of Collaborative Design System

The development of product is a complex process. Collaboration is necessary to this process to support multi-function teams' participation in this process at the same time. Effective task decomposition is the prerequisite of collaborative design and constraint network was used to express the relationship among design participants. In order to make the coupling collaborative design go smoothly, a constraint satisfaction model based on dynamic constraint is put forward. An integrated-based conflict resolution model is advanced to resolve the complex conflict during the process of collaborative design.     

对高等职业技术教育课程设置原则的思考

探索课程设置原则是高职课程建设首先要做的一项重要工作。本文依据高职教育的基本性质与功能，在新型高职课程观的层面上思考高职课程设置的基本原则，以充分体现职业岗位的能力要求，适应经济建设发展和学生个人发展的需要。从而提高学生的职业行为能力，增强学生的就业竞争力。