53例妊娠合并心脏病孕产妇死亡原因分析

目的 分析53例妊娠合并心脏病死亡孕产妇情况及死因,探索相应干预措施,降低孕产妇死亡率.方法 按照孕产妇死亡检测方法,收集2005年1月1日-2009年12月31日湖南省妊娠合并心脏病死亡中53例孕产妇的资料并进行分析.结果 在53例妊娠合并心脏病死亡孕产妇中,可避免死亡的为36例,占67.92%,创造条件可避免死亡的为12例,占22.64%,不可避免死亡的为5例,占9.43%.结论 加强孕产期保健系统管理,提高围产期保健服务水平,加强产科质量的建设,扩大健康教育是降低孕产妇死亡的重要措施.     

妊娠晚期合并重症急性胰腺炎在ICU中的综合治疗

目的：探讨妊娠晚期合并重症急性胰腺炎（SAP）在ICU中的综合治疗效果及其意义。方法：对2006年2月至2012年2月我院中心ICU收治的65例妊娠晚期合并重症急性胰腺炎病例进行回顾性分析。结果：50例患者痊愈出院,12例病情缓解后出院行家庭肠内营养,3例患者自动出院。结论：妊娠晚期合并重症急性胰腺炎病情凶险,一旦确诊,及时终止妊娠,并转入重症监护病房给予综合抢救,方能确保母婴平安。     

智能血液监测器的设计及其应用

阐述了血液监测器原理,并对其结构从理论上进行了分析.介绍了一种应用于血液净化设备的血液监测传感器,临床中检测患者上机与下机过程中血液体外循环管路内血液和生理盐水的变化情况,并及时发出警告,提示医护人员及时处置,以有效增强治疗安全;采用红外传感器发射、接收组件进行非接触式检测,并借助单片机技术进行数据采集与状态识别.     

溶血尿毒综合征患儿的急救及护理

目的：探讨小儿溶血尿毒综合征救护体会。方法：对我院近年收治的15例溶血尿毒综合征（HUS）患儿的临床表现、治疗、护理状况进行总结分析。结果：全部病人均具有HUS的典型临床表现包括溶血性贫血、血小板减少和急性肾功能衰竭,治疗护理的关键是早期改善肾功能衰竭、纠正贫血和预防出血。结论：医务人员正确及时给予治疗和精心护理是影响预后的关键。     

急性冠脉综合征、肾动脉狭窄、急性左心衰三联征的临床研究

目的提高对急性冠脉综合征、肾动脉狭窄、急性左心衰三联征的诊治率。方法回顾性分析25例急性冠脉综合征、肾动脉狭窄、急性左心衰三联征患者的临床资料,分析基线资料与预后的关系。结果高血压、陈旧性心梗、陈旧性脑梗、高脂血症、糖尿病、吸烟、周围血管病等危险因素的发生率分别为100%、54.0%、60.0%、40.0%、48.0%、36%;出现典型心绞痛症状至冠心病确诊(发生心梗/冠脉造影/冠脉CT确诊)平均为5.3年,冠心病确诊-肾动脉狭窄确诊约6.2年,心绞痛症状至肾动脉狭窄确诊约11.5年。造影结果13例为双侧肾动脉狭窄,平均冠脉病变为2.6支,确诊后所有患者进行了冠脉和(或)肾动脉介入或冠脉搭桥术。2例治疗无效死亡,其余23例好转出院,其中3例肾功能较入院时恶化。2年随访期内12例病情好转或稳定,4例死亡,7例发生次级终点事件;因小样本及选择偏倚,无基线资料与预后相关。结论三联征术后及两年预后较差,早期诊断、治疗才能减少发病率及改善预后。     

红细胞扫描电镜样品的快速制作法

近年来红细胞疾病越来越多，许多疑难病例经临床常规方法难以确诊。为使医生对病人的红细胞外形及时了解，以便对病人尽快做出诊断和治疗方案，我们摸索出了一套简洁、快速、方便的红细胞扫描电镜样品的制作方法，经过对百余例临床活检的红细胞进行扫描电镜观察，及时、准确的观察到病人的红细胞外形及表面情况，为临床诊断提供了可靠的依据，其方法介绍如下。     

154例不同年龄先天性肠旋转不良临床比较分析

目的：分析总结先天性肠旋转不良在儿童不同年龄段的临床特点及诊治要点。方法：将我院2003年到2012年间收治的154例先天性肠旋转不良按年龄分为新生儿组（101例）和非新生儿组（53例）,对临床资料进行回顾性分析,总结临床特点及诊治要点。结果：①先天性肠旋转不良多在新生儿期发病,其中以男性患儿多见,性别比例为男：女＝2．67：1。②呕吐是本病的最突出的临床症状,其特点为含大量胆汁的呕吐（89．61％）;新生儿组患儿呕吐症状出现早且严重,而部分非新生儿组（35．85％）肠旋转不良患儿在新生儿期也曾有过呕吐病史。③腹部平片、超声多普勒检查及上消化道造影对本组病例的阳性发现率分别为66．96％、76．79％和100％（P＜0．05）;超声多普勒和上消化道造影确诊肠旋转不良的确诊率分别是49．18％和65．38％（P＜0．05）;上消化道造影对新生儿组和非新生儿组肠旋转不良的确诊率分别是55．38％和82．05％（P＜0．05）。④Ladd’s手术是治疗先天性肠旋转不良的经典术式,多数病例预后好（治愈率96．08％）。结论对于生后早期反复胆汁性呕吐的患儿应考虑先天性肠旋转不良可能,尽早上消化道造影检查明确诊断,早期手术,预后多较好。     

多导睡眠监测护理心得

睡眠呼吸暂停低通气综合征（SAHS）是以反复发作的睡眠期打鼾、呼吸暂停、憋醒,并伴有日间嗜睡、乏力、反应迟钝等一系列临床表现为特征的一种疾病,其病理生理改变以低氧血症、睡眠结构紊乱为特征,其中以阻塞性呼吸睡眠暂停低通气综合征（OSAHS）最为常见。它在成人中的患病率为2%-4%。因此及早诊断、及时治疗具有重要的社会意义。     

肝衰竭患者并发真菌败血症21例

目的回顾性分析我院肝衰竭患者并发真菌败血症的临床特点。方法以1986年1月-2006年6月收治的肝衰竭患者,血培养有真菌生长者为研究对象。结果符合真菌感染诊断509例,其中发生真菌败血症者共21例（4．13％）,60岁以上16例（76．19％）,住院天数平均42．5d。给予抗真菌治疗后治愈5例,好转4例,死亡和／或无效12例。结论真菌败血症多发生于基础疾病重、免疫力低下的肝衰竭患者,死亡率高。其主要病原菌为酵母菌属。延误诊断、治疗不正确以及疗程不足、原发病严重的病例预后差。     

Ho:YAG激光治疗妊娠期尖锐湿疣49例的临床分析

目的分析妊娠期尖锐湿疣的特点,探讨HoYAG激光治疗的疗效及预后.方法 HoYAG激光治疗妊娠期尖锐湿疣49例(妊娠组)和非妊娠期尖锐湿疣49例(对照组),进行对比、回顾分析.结果妊娠组,疣体为巨大型 13例,占26.5%;泛发型14例,占28.6%,复发3次以上者26例,占53.1%;均高于对照组(P《0.05).多次治疗后HoYAG激光治疗两组病例治愈率均100%,手术未致大出血,流产,早产,新生儿未发现明显畸形.结论妊娠期尖锐湿疣易发展为巨大泛发型,易复发.HoYAG激光治疗妊娠期尖锐湿疣安全可靠.     

Analysis of Cross-Layer Interaction in Multirate 802.11 WLANs

Recent works in empirical 802.11 wireless LAN performance evaluation have shown that cross-layer interactions in WLANs can be subtle, sometimes leading to unexpected results. Two such instances are: (i) significant throughput degradation resulting from automatic rate fallback (ARF) having difficulty distinguishing collision from channel noise, and (ii) scalable TCP over DCF performance that is able to mitigate the negative performance effect of ARF by curbing multiple access contention even when the number of stations is large. In this paper, we present a framework for analyzing complex cross-layer interactions in 802.11 WLANs, with the aim of providing effective tools for understanding and improving WLAN performance. We focus on cross-layer interactions between ARF, DCF, and TCP, where ARF adjusts coding at the physical layer, DCF mediates link layer multiple access control, and TCP performs end-to-end transport. We advance station-centric Markov chain models of ARF, ARF-DCF with and without RTS/CTS, and TCP over DCF that may be viewed as multi-protocol extensions of Bianchi's IEEE 802.11 model. We show that despite significant increase in complexity the analysis framework leads to tractable and accurate performance predictions. Our results complement empirical and simulation-based findings, demonstrating the versatility and efficacy of station-centric Markov chain analysis for capturing cross-layer WLAN dynamics.     

一种基于IEEE 802.11的多速率自适应MAC协议

提出了一种新颖的基于连续ACK帧统计信息的IEEE 802.11多速率自适应MAC协议EARF(EnhancedARF),其主要思想是:每一个速率有各自的成功阈值——速率升高的门限值,并且该值根据信道状况(用延时因子量化)动态地变化。协议不需对现有的IEEE 802.11标准做任何修改,因此易于通过编写驱动程序实现。仿真表明在大多数信道条件下,该协议性能较现有的基于ACK帧统计的速率自适应协议如ARF,ARF3-10都有较大的提高。     

Training an Active Random Field for Real-Time Image Denoising

Many computer vision problems can be formulated in a Bayesian framework based on Markov random fields (MRF) or conditional random fields (CRF). Generally, the MRF/CRF model is learned independently of the inference algorithm that is used to obtain the final result. In this paper, we observe considerable gains in speed and accuracy by training the MRF/CRF model together with a fast and suboptimal inference algorithm. An active random field (ARF) is defined as a combination of a MRF/CRF based model and a fast inference algorithm for the MRF/CRF model. This combination is trained through an optimization of a loss function and a training set consisting of pairs of input images and desired outputs. We apply the ARF concept to image denoising, using the Fields of Experts MRF together with a 1-4 iteration gradient descent algorithm for inference. Experimental validation on unseen data shows that the ARF approach obtains an improved benchmark performance as well as a 1000-3000 times speedup compared to the Fields of Experts MRF. Using the ARF approach, image denoising can be performed in real-time, at 8 fps on a single CPU for a 256times256 image sequence, with close to state-of-the-art accuracy.     

氩缓冲气体对锶原子共振滤波器通频带的影响

通频带是原子共振滤波器的重要参数。本文研究了不同氩缓冲气压对锶原子共振滤波器通频带的影响,为锶原子共振滤波器作成器件和其它原子共振滤波器的研究提供了有价值的实验结果。     

Adaptive threshold control for auto-rate fallback algorithm in IEEE 802.11 multi-rate WLANs

The IEEE 802.11 standard supports multiple rates for data transmission in the physical layer. Nowadays, to improve network performance, a rate adaptation scheme called auto-rate fallback (ARF) is widely adopted in practice. However, ARF scheme suffers performance degradation in multiple contending nodes environments. In this article, we propose a novel rate adaptation scheme called ARF with adaptive threshold control. In multiple contending nodes environment, the proposed scheme can effectively mitigate the frame collision effect on rate adaptation decision by adaptively adjusting rate-up and rate-down threshold according to the current collision level. Simulation results show that the proposed scheme can achieve significantly higher throughput than the other existing rate adaptation schemes. Furthermore, the simulation results also demonstrate that the proposed scheme can effectively respond to the varying channel condition.     

Atomic resonance filters

The atomic resonance filter (ARF) is an ultranarrowband (Q~10⁵-10⁶), large-acceptance-angle, isotropic optical filter. These features make the device ideally suited for applications in which weak laser signals are detected against a continuum background. The filter properties arise from the physical processes of absorption, emission, and internal energy conversion in atomic vapors. The characteristics of the ARF are described and the underlying physics that governs the operation is discussed. Representative examples of passive, active, and IR filters are presented. A metastable ARF that offers improved solar background-limited performance by filtering signals at Fraunhofer wavelengths is described     

光电离检测的Cs原子共振滤波

本文报导一种新型的、使用光电离检测的Cs原子共振滤波方案.理论算得:原子系统固有的响应时间为10ns,线宽62MHz,量子效率86.6%,初步实验测得:响应时间(包括系统因素)130ns,量子效率大于10.1%,最小可探测光强3nJ.实验系统正在进一步改善,可以期望获得更好的实验值.     

温度及氩缓冲气体对锶原子共振滤波器响应时间的影响

响应时间是原子共振滤波器的性能的重要参数。本文说细研究了不同温度及不同氩缓冲气压对锶原子共振滤波器响应时间的影响,为锶原子共振滤波器作成器件和其它滤波器的研究提供了有价值的实验结果。     

电容式RF MEMS开关膜片边缘场效应的表征

计及电容式RF MEMS开关膜片上电场分布的边缘场效应后,很难建立高保真的开关自驱动失效阈值功率解析模型。因此,采用膜片承受射频信号功率的面积(ARF)和膜片与传输线的正对面积(A)的比值构建优值(Fo M),以表征膜片上电场分布的边缘场效应强弱。利用HFSS软件建立了开关自驱动失效的三维电磁模型;以一种常见的开关构型为案例,仿真得到了多种射频信号功率(Pin)和开关气隙高度(g0)条件下膜片边缘电场分布,并与优值计算结果进行了对比验证,初步证明了采用优值ARF/A表征膜片上电场分布的边缘场效应强度的可行性。     

Throughput study for admission control in IEEE 802.11 DCF with ARF

We propose an analytical approach to determining the admission of new stations to a WLAN operating in IEEE 802.11 Distributed Coordination Function (DCF) with Auto Rate Fallback (ARF). The proposed approach is based on a cross layer analytical model of how the throughput of existing stations in the WLAN is affected by admitting the new station in non-saturated as well as saturated traffic conditions. The effectiveness of the proposed approach is verified by simulations.