A method of identifying the blood contributor in mixture stains through detecting blood-specific mRNA polymorphism

In the past decades, messenger RNA (mRNA) biomarkers have been employed to identify the origin of body fluids in forensic medicine. We hypothesized that the polymorphism of mRNA could be applied to identify individuals in mixture samples composed of two body fluids. In this study, we selected five blood-specific mRNA biomarkers of venous blood (SPTB, CD3G, AMICA1, ANK1, and GYPA) that encompass 16 SNPs to identify the mixture contributor(s). Five specific gene markers for menstrual blood, semen, skin, saliva, and vaginal secretions were amplified and typed as body-fluid positive controls. We established the system of multiplex PCR and single base extension (SBE) reaction followed by CE. The amplicon size was between 90bp and 294bp. The peripheral blood specificity was examined against other human body fluids, including saliva, semen, skin, menstrual blood, and vaginal secretion. The 16 SNPs were peripheral blood specific and could be successfully typed in homemade mixtures which are composed of different body fluids with 1 ng peripheral blood mRNA added. This system showed a supersensitivity (1:100) in detecting the trace amount of peripheral blood mixed in other body fluids and a combined discrimination power (CDP) of 0.99929 in Chinese population. It was the first time to establish a method for identifying the blood donors and deconvoluting mixtures through detecting mRNA polymorphism with SNaPshot assay. This peripheral blood specific SNP typing system showed high sensitivity to the typing of blood source specific markers regardless of other body fluids in the mixture.     

泡沫镍载碳化钨催化剂上的析氢反应

结合直接化学还原法和交替微波法制备了泡沫Ni载Ni-WC催化剂,用X射线衍射、扫描电镜和透射电镜对催化剂进行了表征,研究了其析氢电催化性能.结果表明,在相同条件下,泡沫Ni载Ni-WC催化剂的析氢起始电位与泡沫Ni相比降低了60 mV左右.电解质浓度和温度对泡沫Ni载Ni-WC催化剂的析氢电催化活性有很大影响.     

电解水金属单原子催化剂的研究进展

氢能因其能量密度高、清洁无污染等特点,作为替代化石燃料的能源载体得到了广泛的研究.如何清洁高效地制备氢气受到了大量研究者的关注.当前,以化石能源的热反应所得副产氢气是主要来源.然而,采用该类方法不仅不能摆脱化石能源的使用以及温室气体的排放,还会造成生产氢气的纯度不高,碳氧化物杂质浓度过高的问题,严重影响氢气的后续使用.采用可再生能源(太阳能、风能等)所产富余电,进行电解水制氢,产生的氢气不含碳氧化合物杂质,纯度很高,可以真正实现碳的零排放,被认为是未来氢气来源的重要方式.目前,电解水制氢在制氢市场的所占份额较小,而造成这样局面的主要因素是该过程中的高能耗问题.为了降低能耗,开发高效催化剂加速两个电极上的电解反应的动力学尤为重要.近年,金属单原子催化剂(SACs)因其独特的结构,在很多研究中被用作电解水催化剂,进而开发出大量高性能的金属单原子电解水催化剂.本文综述了近年SACs在电解水催化方面的应用.首先,针对电解水反应本身,总结了阴阳极两侧的电极反应机制以及影响电极催化性能的关键吸附中间物种;然后,根据载体的不同,即合金、碳以及其它化合物将SACs分为三类,总结了相关电解水催化研究现状,并且针对不同类型SACs目前的发展情况,提出了它们各自存在的问题.其次,进一步总结了影响SACs电解水催化活性的因素,提出了四种决定SACs催化性能的影响因子,分别为金属原子的固有元素性质、配位环境、几何结构和负载量;同时讨论了这四类影响因素对SACs催化活性的影响机制,总结了调控各类影响因素的方法,为SACs的设计提出了一些建议.最后,展望了SACs在电解水催化中的应用,探讨了SACs在催化剂设计及催化机制研究方面的问题,提出了SACs在电解水催化中的未来发展方向.     

TiO2光催化氧化研究进展

探讨了TiO2光催化氧化技术的原理,其研究现状,以及可能提高TiO2光催化氧化效率的途径。采用参考文献18篇。     

High Pt utilization PEMFC electrode obtained by alternative ion-exchange/electrodeposition

High Pt utilization PEMFC electrodes were prepared by an alternative ion-exchange/electrodeposition (AIEE) technique. The results demonstrated that the MEA employing an AIEE electrode with a Pt loading of 0.014 mg Pt cm(-2) exhibits performance approximately 2.2 times larger than that employing a conventional Nafion-bonded Pt/C electrode with a same Pt loading.     

钨合金柱形弹超高速撞击水泥砂浆靶的侵彻深度研究

为探索钨合金柱形弹超高速撞击水泥砂浆靶的侵彻深度随撞击速度变化规律,利用二级轻气炮开展了?3.45 mm×10.5 mm的克级93 W钨合金柱形弹以1.82~3.66 km/s的速度撞击水泥砂浆靶的实验,利用CT图像诊断技术获得了侵彻深度和残余弹长随撞击速度的变化规律,对超高速撞击过程进行了数值模拟,结合数值模拟结果进一步分析了超高速撞击物理过程。结果表明:(1)超高速撞击条件下成坑是弹坑+弹洞型;(2)侵深-速度曲线呈现先增大后减小的现象,在弹速2.6 km/s附近存在侵彻深度极大值,约为8.5倍弹长,相对于中低速侵彻的深度并没有显著优势。(3)通过基于数值模拟得到的弹靶界面压力时程曲线将侵彻过程分为4个阶段,其中准定常侵彻阶段和第三侵彻阶段是决定总侵深的主要阶段。(4)随撞击速度增加,弹体侵蚀逐渐剧烈,此时准定常侵彻阶段的侵深变化不大,而第三侵彻阶段中的刚体侵彻部分大幅降低,导致总侵深大幅降低,使总侵深曲线呈现先增大后减小的现象。     

Three‐Arm Branched Microporous Organic Nanotube Networks

Here, a novel method is demonstrated for the preparation of three‐arm branched microporous organic nanotube networks (TAB‐MONNs) based on molecular templating of three‐arm branched core–shell bottlebrush copolymers and Friedel–Crafts alkylation reaction. The unique three‐arm branched bottlebrush copolymers are synthesized by a combination of atom transfer radical polymerization, reversible addition‐fragmentation chain transfer polymerization, and ring‐opening polymerization techniques. In this approach, the length and diameter of branched tube units can be well‐controlled by rational molecular design. Moreover, the as‐prepared TAB‐MONNs possess a high surface area and exhibit a superior adsorption capacity for Rhodamine 6G (R6G) and p‐cresol.

     

Variance-constrained dissipative observer-based control for a class of nonlinear stochastic systems with degraded measurements

This paper is concerned with the variance-constrained dissipative control problem for a class of stochastic nonlinear systems with multiple degraded measurements, where the degraded probability for each sensor is governed by an individual random variable satisfying a certain probabilistic distribution over a given interval. The purpose of the problem is to design an observer-based controller such that, for all possible degraded measurements, the closed-loop system is exponentially mean-square stable and strictly dissipative, while the individual steady-state variance is not more than the pre-specified upper bound constraints. A general framework is established so that the required exponential mean-square stability, dissipativity as well as the variance constraints can be easily enforced. A sufficient condition is given for the solvability of the addressed multiobjective control problem, and the desired observer and controller gains are characterized in terms of the solution to a convex optimization problem that can be easily solved by using the semi-definite programming method. Finally, a numerical example is presented to show the effectiveness and applicability of the proposed algorithm.