心源性猝死一级预防植入心律转复除颤器前非持续室性心动过速与植入后恰当治疗的关系

目的探讨植入型心律转复除颤器(implantable cardioverter defibrillator,ICD)用于心源性猝死一级预防时,植入前发生非持续性室性心动过速(non-sustained ventricular tachycardia,NSVT)与植入后ICD恰当治疗的关系。方法本研究为单中心回顾性队列研究,连续纳入2006年1月至2017年12月在北京协和医院住院植入ICD用于一级预防的心脏病患者,患者在住院期间ICD植入前均完善Holter检查。根据Holter检查是否出现NSVT,将患者分为NSVT组及无NSVT组。门诊或电话随访至2018年8月,随访事件包括全因死亡、植入后ICD放电治疗及抗心动过速起搏(antitachycardia pacing,ATP)治疗情况。结果纳入60例符合入选和排除标准的患者,随访时间37 (14～61)个月,KaplanMeier生存曲线及Log-Rank检验提示,NSVT组与无NSVT组相比,全因死亡率无统计学差异(P=0. 108),NSVT组恰当治疗的风险高于无NSVT组(P=0. 033),NSVT和左心室射血分数与ICD恰当治疗独立相关(NSVT:HR=5. 099,95%CI:1. 399～18. 588,P=0. 014;左心室射血分数:HR=1. 077,95%CI:1. 013～1. 145,P=0. 018)。结论 ICD一级预防患者植入前出现NSVT提示接受ICD恰当治疗的风险增加。     

黑河右岸溢洪洞左导墙优化试验

黑河水利枢纽右岸溢洪洞为缩短引渠左导墙的长度,减少施工开挖量,降低施工难度,减少工程投资,进行优化试验.通过对7种不同的方案对比分析,选择了合适的体型,满足了工程要求.     

热轧左旋螺纹钢的开发

介绍了在轧钢厂二车间开发顾客需要的Φ18、Φ20、Φ22的热轧左旋螺纹钢。在原有Φ18、Φ20、Φ22热轧圆钢的工艺基础之上做工艺设计，经实际生产轧制，其产品质量完全符合顾客要求。     

"The association between emotional upset and cardiac arrhythmia during daily life": Correction to Carels et al. (2003).

Reports an error in the original article by R. A. Carels et al (Journal of Consulting & Clinical Psychology, 2003[Jun], Vol 71[3], 613-618). On page 615, Lines 18, 20, 22, of Table 1, the data in the rows that read "Tachycardia in min per hr," "Repetitive PVCs per hr," and "PVCs per hr" are incorrectly reported in the n and % columns. They should have been reported in the M and SD columns. The corrected table is provided. (The following abstract of this article originally appeared in record 2003-00756-023.) Ventricular arrhythmia exhibits considerable within-subject variability that cannot be attributed to clinical status alone. This investigation examined the extent to which cardiac arrhythmia was associated with psychological and physical factors assessed during the hour preceding arrhythmic or nonarrhythmic activity. Approximately twice hourly, 46 patients randomly completed a diary assessing mood and physical symptoms during 24-hr electrocardiographic monitoring. Greater negative emotion was associated with increased arrhythmia. Additionally, greater negative emotion was significantly associated with increased arrhythmia among participants in a low left ventricular ejection fraction group (LVEF). However, this relationship between negative emotion and arrhythmia was not... (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

基于复合左右手传输线结构的新型微带天线

基于复合左右手传输线结构的零阶谐振理论,提出了一种新型双层结构的微带天线,仿真结果表明该天线具有比单层微带天线更小的尺寸。研究了天线各结构参数对天线特性的影响,并对各参数进行了优化仿真。仿真结果表明该天线具有全向辐射特性,与传统微带天线相比,该天线具有体积小的特点。     

一类差分方程的渐近概周期序列解的存在性

利用渐近概周期函数以及序列的定义和基本性质,得出下面离散系统存在正渐近概周期序列解唯一性的充分条件.     

几乎最佳自相关二元序列偶的搜索算法研究

提出了利用几乎最佳自相关二元序列偶的变换性质和存在组合的必要条件,来缩小它的搜索范围,提高计算机搜索效率。在此基础上设计了高效的计算机搜索算法。并给出了若干小规模的规范型几乎最佳自相关二元序列偶实例。搜索结果表明,几乎最佳白相关二元序列偶具有较大的存在空间,可以应用到工程中。     

异构网络中几乎空白子帧存在时干扰协调方法

针对异构网络中几乎空白子帧存在时用户接入选择和资源分配方法过于复杂的情况,以及吞吐量需求难以得到满足问题,以最大化系统总吞吐量为目标提出一种易于实现的蚁群算法.在考虑不同用户不同需求的前提下,根据微基站用户在几乎空白子帧和正常子帧时受到干扰的不同,把一个微基站划分为两个虚拟基站,将所存在的问题建模为广义分配问题进行求解,同时解决了用户接入选择和资源分配问题.仿真结果表明,所提出方法与参考文献方法及两种增强型小区干扰协调固定配置结果相比,可以有效提高系统总吞吐量,同时兼顾小区边缘用户吞吐量,实现了良好的综合性能,能够更好地满足用户需求并在实际系统中易于实现.     

一类随机积分-微分方程的均方渐近概周期解

随机微分方程是在解决某些具有随机现象建立起来的一类方程,其中随机微分方程的均方渐近概周期解相比于均方概周期解应用更加广泛.为了研究均方渐近概周期过程在随机微分方程中的应用,利用均方渐近概周期函数的相关性质以及Banach不动点原理讨论了一类随机积分-微分方程均方渐近概周期解的存在性和唯一性.     

Stability analysis and control for switched stochastic delayed systems

This paper investigates almost sure exponential stability and feedback stabilization for switched time‐delay systems with nonlinear stochastic perturbations. The main contributions of this paper are threefold: (i) based on the non‐convolution type multiple Lyapunov functionals and the mathematical induction approach, a mean‐square exponential stability condition for nonlinear stochastic switched systems is first established, such that the obtained average dwell time does not rely on any given decay rate; (ii) by using the method developed in part (i) and the stochastic analysis techniques and limit methods in probability, an almost sure exponential stability criterion for switched delayed systems with nonlinear stochastic uncertainties is presented, and then a state feedback controller for the systems under consideration is designed; and (iii) when certain assumptions are made on the nonlinear stochastic perturbations, the results in this paper are further improved by relaxing some conditions. The effectiveness of the proposed method is demonstrated by three illustrative examples. Copyright © 2015 John Wiley & Sons, Ltd.