Single-cell RNA sequencing reveals B cell–related molecular biomarkers for Alzheimer’s disease

In recent years, biomarkers have been integrated into the diagnostic process and have become increasingly indispensable for obtaining knowledge of the neurodegenerative processes in Alzheimer’s disease (AD). Peripheral blood mononuclear cells (PBMCs) in human blood have been reported to participate in a variety of neurodegenerative activities. Here, a single-cell RNA sequencing analysis of PBMCs from 4 AD patients (2 in the early stage, 2 in the late stage) and 2 normal controls was performed to explore the differential cell subpopulations in PBMCs of AD patients. A significant decrease in B cells was detected in the blood of AD patients. Furthermore, we further examined PBMCs from 43 AD patients and 41 normal subjects by fluorescence activated cell sorting (FACS), and combined with correlation analysis, we found that the reduction in B cells was closely correlated with the patients’ Clinical Dementia Rating (CDR) scores. To confirm the role of B cells in AD progression, functional experiments were performed in early-stage AD mice in which fibrous plaques were beginning to appear; the results demonstrated that B cell depletion in the early stage of AD markedly accelerated and aggravated cognitive dysfunction and augmented the Aβ burden in AD mice. Importantly, the experiments revealed 18 genes that were specifically upregulated and 7 genes that were specifically downregulated in B cells as the disease progressed, and several of these genes exhibited close correlation with AD. These findings identified possible B cell-based AD severity, which are anticipated to be conducive to the clinical identification of AD progression.Subject terms: Cell death in the nervous system, Neurotrophic factors     

正交插值与脉冲压缩的最佳滤波器设计

提出了以吞吐率最大为准则利用频域分段算法进行FIR滤波的方法.推导了雷达信号处理中正交插值和脉冲压缩处理的频域算法,针对长信号序列的频域滤波处理,研究了分段滤波方法,得出了最佳分段长度.并将正交插值和脉冲压缩处理在频域合并起来,进一步降低了运算量.     

酶分子在试管内的定向进化及其在手性有机物合成中的应用

本文扼要介绍了当今改进酶分子性能的有效手段——分子定向进化技术的基本方法如易错PCR和DNA洗牌,以及派生的一暨新技术的原理与进展,并列举了在手性有机物合成中一些成功的实例,为该领域的研究与应用提供了一些新的信息。     

解读无线通信设备电磁兼容系列标准通用要求

介绍了无线通信设备电磁兼容性要求和测量方法的通用技术要求,如试验布置、免测频段、窄带响应、性能判据等,并对复合无线电设备、多模终端的电磁兼容测试导则进行了解读。     

Kinetically Controlled Coprecipitation for General Fast Synthesis of Sandwiched Metal Hydroxide Nanosheets/Graphene Composites toward Efficient Water Splitting

The development of cost‐effective and applicable strategies for producing efficient oxygen evolution reaction (OER) electrocatalysts is crucial to advance electrochemical water splitting. Herein, a kinetically controlled room‐temperature coprecipitation is developed as a general strategy to produce a variety of sandwich‐type metal hydroxide/graphene composites. Specifically, well‐defined α‐phase nickel cobalt hydroxide nanosheets are vertically assembled on the entire graphene surface (NiCo‐HS@G) to provide plenty of accessible active sites and enable facile gas escaping. The tight contact between NiCo‐HS and graphene promises effective electron transfer and remarkable durability. It is discovered that Ni doping adjusts the nanosheet morphology to augment active sites and effectively modulates the electronic structure of Co center to favor the adsorption of oxygen species. Consequently, NiCo‐HS@G exhibits superior electrocatalytic activity and durability for OER with a very low overpotential of 259 mV at 10 mA cm^?2. Furthermore, a practical water electrolyzer demonstrates a small cell voltage of 1.51 V to stably achieve the current density of 10 mA cm^?2, and 1.68 V to 50 mA cm^?2. Such superior electrocatalytic performance indicates that this facile and manageable strategy with low energy consumption may open up opportunities for the cost‐effective mass production of various metal hydroxides/graphene nanocomposites with desirable morphology and competing performance for diverse applications.     

激光测距机故障快速诊断方法研究

根据激光测距机的结构和功能特点,应用贝叶斯决策理论研究出一种建立激光测距机故障字典、快速实现故障诊断的方法。该方法普遍适用于已有维修经验积累的激光测距机常见故障诊断和维修决策。     

新型复杂光电仪器的故障诊断方法研究

新型复杂光电仪器的技术保障面临着仪器知识少、没有维修经验积累等困难,为尽快提高有关技术人员的保障能力,研究了构建仪器层次分解工作模型的方法和进行仪器结构基元的故障预测、故障繁衍、故障诊断的策略,以使技术人员尽快掌握仪器知识,具备故障诊断维修的能力。     

计算机通信技术在配电网中的应用探讨

自动化配电网是电网智能化建设的重要组成部分。通过优化网络能够平衡电网功率负载,可以最大程度地减少网络通信损耗,从而提高电网运行效率。在配电网中常用的计算机铜锡技术包括现场总线技术(FB)技术和光纤通信技术。其中光纤通信技术凭借低损耗,长距离、抗干扰、体积小、宽频带、高带宽等优点逐渐取代微波网络成为主要的配电网通信技术。文章的主要目的是研究光纤通信技术在配电网中的应用,介绍了计算机通信技术的概念以及配电网的常用计算机通信技术,在此基础上探讨了基于光纤通信技术的配电网通信网络总体结构以及骨干层、接入层的设计方案,并进行总结。     

Joint overlay and underlay resource allocation with weighted fairness in OFDM‐based cognitive radio systems

In this paper, the problem of hybrid overlay and underlay spectrum access is investigated for OFDM‐based cognitive radio (CR) systems. Both the metrics for system (e.g. capacity) and users (e.g. fairness) are integrated into the unified framework of weighted‐capacity maximization with the interference constraint in CR systems. For easing the procedure of resource allocation, two criteria, respectively, for subcarrier assignment and power allocation are theoretically derived based on the Karush–Kuhn–Tucker conditions. Under the guidance of the two criteria, max‐capacity subcarrier assignment and optimal power allocation are proposed to flexibly distribute spectrum resources to secondary users. In order to reduce the computational complexity further, a suboptimal power allocation algorithm, referred to as cap‐limited waterfilling, is also presented by decomposing the interference constraint. Simulation results show that the capacity and fairness performance of the proposed algorithms is considerably better than the conventional ones in references. The proposed suboptimal algorithm with substantially lower complexity approaches to optimal power allocation in the vicinity of only 1% performance gap. Meanwhile, joint access model is greatly beneficial to spectrum efficiency enhancement in CR systems. Copyright © 2014 John Wiley & Sons, Ltd.