气囊压迫止血器初次放气减压时间不同对桡动脉介入术后安全性的系统评价

目的:系统评价桡动脉介入术后气囊压迫止血器不同初次放气减压时间对病人术后安全性的影响,并探究最佳初次放气时间。方法:系统检索PubMed、Web of Science、EMbase、中国期刊全文数据库(CNKI)、维普、万方数据库中2005年1月1日—2021年12月15日公开发表的包含桡动脉介入术后气囊压迫止血器不同初次放气时间对术后不良反应及并发症影响的随机对照试验(RCT)。采用RevMan 5.4软件进行Meta分析,运用R 4.2软件进行敏感性分析。结果:共纳入27项研究,涉及病人5843例。Meta分析结果显示,与术后>2 h初次放气减压相比,术后2 h初次放气减压急性桡动脉闭塞(RAO)发生率[RR=4.90,95%CI(1.69,14.24),P=0.003]、肢体麻木发生率[RR=3.16,95%CI(2.14,4.65),P<0.00001]、肢体发绀发生率[RR=4.35,95%CI(2.36,8.02),P<0.01]更低。与术后2 h初次放气减压相比,术后<2 h初次放气减压急性RAO发生率[RR=0.44,95%CI(0.20,0.97),P=0.04],肢体肿胀发生率[RR=0.41,95%CI(0.27,0.63),P<0.0001]、肢体麻木发生率[RR=0.49,95%CI(0.34,0.70),P<0.0001],肢体发绀发生率[RR=0.37,95%CI(0.18,0.75),P=0.006],病人穿刺部位疼痛发生率[RR=0.50,95%CI(0.34,0.73),P=0.0003]更低。采用逐一剔除文献方法进行敏感性分析,剔除前后结果未发生明显变化,提示Meta分析结果基本稳定。结论:现有证据表明,气囊压迫止血器初次放气减压时间距桡动脉介入术后<2 h比2 h或>2 h更能有效预防术后急性RAO及肢体肿胀、麻木、发绀、穿刺部位疼痛的发生。

两种确定肺段间平面的胸腔镜精准肺段切除术的临床对照研究

目的 比较单纯动脉结扎法与改良膨胀萎陷法在胸腔镜精准肺段切除术中确定肺段间平面的应用效果。方法 前瞻性纳入2021年8月至2023年2月于本院行胸腔镜精准肺段切除术的80例患者,采用随机数字表法将患者分为观察组和对照组,每组40例。观察组患者采用单纯动脉结扎法确定肺段间平面,对照组患者采用改良膨胀萎陷法确定肺段间平面。比较2组患者围术期相关指标、肺功能指标、术后并发症及随访情况。结果 观察组患者手术时间及术中出血量均显著短/少于对照组(P<0.05);而2组患者段间平面显现时间、术后总引流量、引流管留置时间、术后住院时间及肺段切除分布情况比较,差异均无统计学意义(P>0.05)。术后2组患者用力肺活量占预计值百分比(FVC%pred)、第1秒用力呼气容积占预计值百分比(FEV1%pred)较术前均显著降低(P<0.05),且观察组患者术后FVC%pred、FEV1%pred显著高于对照组(P<0.05)。2组患者术后各并发症的发生情况比较,差异均无统计学意义(P>0.05)。随访期间所有患者均未出现死亡、肿瘤局部复发或远处转移情况。结论 在胸腔镜精准肺段切除术中应用单纯动脉结扎法确定段间平面较改良膨胀萎陷法具有操作简便、损伤小、对患者肺功能影响小等显著优势,安全性较高,是一种可行且有效的技术。

基于Deflation技术的预调制Restarted GMRES算法

电学层析成像的图像重建需要对逆问题进行求解,而求解过程中存在着非线性、欠定性以及病态性严重等难题,使得图像重建可能不收敛,或者致使收敛,但获得的图像分辨率较低。针对现有的一些图像重建算法,提出基于Deflation技术的预调制Restarted GMRES算法,在原有full GMRES算法基础上,提高了收敛速度以及图像成像分辨率,并通过仿真实验证明。

一种ARGB数据无损压缩解压算法的FPGA设计

提出了一种ARGB数据的无损压缩优化算法以及FPGA实现方法;为了避免对整个文件的解压和压缩,采用了Deflate算法的相关方法对图像按块进行压缩和解压,极大提高了存储器的访问效率;利用了Deflate算法对小块进行压缩,发挥了Deflate中LZ77压缩的Huffman压缩技术来优化压缩算法;通过VIVADO HLS将算法实现成FPGA电路,采用多张图片进行了实际应用,证实了算法的有效性,并分析了其功耗和时序信息。

寒冷地区外窗热工性能对建筑采暖空调负荷的影响

【目的】通过研究外窗热工性能对建筑采暖空调负荷的影响,得出各项外窗热工性能参数对建筑节能效果的影响程度,有助于提升建筑的节能效果。【方法】利用DeST-h,建立寒冷地区(郑州)75%节能标准居住建筑基本模型,以太阳得热系数、窗墙比、外窗传热系数为变量进行单因素影响计算,以窗墙比和太阳得热系数、建筑层数和太阳得热系数为变量进行多因素分析,研究太阳得热系数、窗墙比、外窗传热系数对建筑采暖空调负荷的影响。【结果】结果表明,窗墙比、传热系数对建筑采暖空调负荷影响趋势明显,均呈正相关;太阳得热系数对建筑采暖空调负荷影响趋势与建筑窗墙比、建筑层数有关。【结论】建筑外窗节能应优先考虑窗墙比、传热系数,同时在确定当地太阳得热系数时应兼顾窗墙比和建筑层数,以满足更高的节能标准。

基于智能手机的中央充放气调试系统

文章主要介绍一种基于智能手机的中央充放气调试系统,旨在提高中央充放气系统的调试效率和便捷性。随着智能手机性能的不断提升,将其与汽车诊断接口相连接,结合自主开发的调试应用程序,可以实现充放操作、故障诊断、参数设置、数据监控和实验数据记录等5大功能。文章详细描述这一方法的工作原理、步骤和优势,并通过附图和具体实施方式加以阐释。该方法的应用将有望减少中央充放气系统调试的时间成本,提高调试效率,便于维修和数据记录的管理。

基于FPGA的Deflate算法核心模块设计

基于嵌入式设备FPGA,对无损压缩算法Deflate算法进行加速。采用哈希表方法,把Deflate核心算法用在FPGA上,实现了软硬件协同设计。独创性地设计并实现了窗口大小为32K的Deflate算法。主要介绍该设计的哈希表模块部分。

Tracking multiple targets in MIMO radar via adaptive asymmetric joint diagonalization with deflation

In view of the low performance of adaptive asymmetric joint diagonalization（AAJD）, especially its failure in tracking high maneuvering targets, an adaptive asymmetric joint diagonalization with deflation（AAJDd） algorithm is proposed. The AAJDd algorithm improves performance by estimating the direction of departure（DOD） and direction of arrival（DOA） directly, avoiding the reuse of the previous moment information in the AAJD algorithm.On this basis, the idea of sequential estimation of the principal component is introduced to turn the matrix operation into a constant operation, reducing the amount of computation and speeding up the convergence. Meanwhile, the eigenvalue is obtained, which can be used to estimate the number of targets. Then, the estimation of signal parameters via rotational invariance technique（ESPRIT） algorithm is improved to realize the automatic matching and association of DOD and DOA. The simulation results show that the AAJDd algorithm has higher tracking performance than the AAJD algorithm, especially when the high maneuvering target is tracked. The efficiency of the proposed method is verified.

Structural Research on Embedment of a Bare Deflated Spiral Case

Complete bearing spiral case has not been applied to large power stations in China so far. The proposal of applying complete bearing spiral case necessitates an analysis of the reliability of the spiral case structure and the security of units under various working conditions. In combination with practice of a project, this paper presents a three-dimensional nonlinear finite element static analysis of the concrete using a concrete smeared crack model by means of the well-known finite element method （FEM） software ABAQUS. The stress distribution of the spiral case and reinforcing bars, the range of damages in surrounding concrete, and the displacement of structure are quantified. The computational results indicate that the embedment method ensures the structure＇s safety in strength. At the same time, the result shows that this embedment is a kind of preponderant method for embedment in aspects of economy and technique of construction, and the application of this embedment method to the hydropower station is feasible provided that some proper engineering measures are taken to constrain the width of the concrete in accord with the code＇s requirements. The paper proves the security and reliability of the structural design of spiral case in hydropower station accordingly.

Immediate balloon deflation method in endoscopic papillary large balloon dilation for extraction of difficult bile duct stones

Background/Aims: Recently, endoscopic papillary large balloon dilation (EPLBD) using a large balloon (12 - 20 mm) for extraction of difficult common bile duct (CBD) stones has been widely accepted with favorable outcomes. However, there is no consensus with regard to the ballooning time. The aim of our study was to evaluate the efficacy and safety of immediate balloon deflation in EPLBD for the treatment of difficult bile duct stone. Methods: This was a retrospective study of 80 consecutive patients with bile duct stones who were treated with an immediate balloon deflation method in EPLBD combined with endoscopic sphincterotomy (EST) between January 2010 and December 2012. Overall success rate, success rate at first ERCP, and the frequency of mechanical lithotripsy for complete stone removal were assessed for efficacy and safety was evaluated by assessing major complications. Results: Overall success rate for complete stone removal was high (78/80, 97.5%) and success rate for complete stone removal at first ERCP was 86.3% (69/80). The use of mechanical lithotripsy was 0% (0/80). The overall complication rate was favorable (5/80, 6.3%). PostERCP pancreatitis was observed in 3 patients (two: mild, one: moderate). In subgroup analysis, the presence of periampullary diverticulum was the only factor affecting the success rate at first ERCP. Conclusion: This study demonstrated the favorable outcome of immediate balloon deflation for treatment of difficult CBD stones and can be considered for clinical application.

基于数据分析的DEFLATE算法特征研究

DEFLATE压缩算法作为计算机领域中使用最广泛的开源压缩算法,大量网络协议和应用程序使用该算法对数据进行压缩处理。在当前大数据时代,无论对数据压缩算法进行适应性改进,还是为网络流量识别中的压缩流量识别提供依据,都需要对数据压缩算法特征进行分析研究。采用数据分析方法,根据DEFLATE算法流程特点,对算法进行模块分割,设计卡方、信息熵、加权累积和、字节游程均值4项分析指标,对DEFLATE算法特征进行分析研究,发现其包含的LZ77模块压缩性能和整个算法联系紧密,不同类型数据经过DEFLATE算法压缩后,分析指标在趋向一致的同时又表现出一定的区分性,表明DEFLATE算法在压缩效率方面较为依赖LZ77压缩模块,相比压缩前数据,压缩数据更加趋近于随机数据,另外不同类型文件对应的压缩数据,其统计特征也表现出一定的差异性。

Deflation rates of different clastic sediments in the arid regions of China

By wind tunnel experiment, we studied the deflation rates of 8 different clastic sediments in the arid regions of China, discussed the sources of aeolian sand and their influence on the development of sand dunes and formation of sand deserts from the view of dynamics of wind erosion. The average deflation rates of 8 typical clastic sediments in the arid regions of China can be arranged in the order of lacustrine sand 〉 alluvial sand 〉 weathered sandstone and shale 〉 pluvial sediments 〉 fluvioglacial sand 〉 weathered granite 〉 slope deposit 〉 glacial sediments. The deflation rates exhibited strong positive correlations with the erodible particle （0.063 2mm） content and sorting features. In contrast, the deflation rates had obvious negative correlations with the contents of silt clay （〈0.063 mm） and gravel （〉2 mm）. According to the deflation rates, the 8 typical clastic sediments can be divided into four categories： （1） lacustrine and alluvial sand, which are readily prone to wind erosion, assumed to be the main source of aeolian sand; （2） weathered sandstone and shale, pluvial sediments and fluvioglacial sand with considerable deflation rates, might be the secondary source of aeolian sand; （3） weathered granite and slope deposit having the lower deflation rates, could supply a little aeolian sand; and （4） glacial sediments with a strong anti-erodibility, could hardly offer any aeolian sand. In addition to the strong wind conditions, the exposure of extensive lacustrine sand induced by the desiccation of inland lake basin, as well as the pre-sorting of clastic sediments by flowing water should be the key factors influencing the development of sand deserts in China. The possible reason the sand deserts in China being mostly distributed around the inland lake basins and along riverbanks could be better understood through sand source analysis.

Deflation and Stock Prices

While the literature on inflation and stock prices is plentiful,there is little literature on deflation and stock prices.This paper explores the empirical data and makes a theoretical analysis of the likely impact on stock prices when expectations change from inflation to deflation.Deflation has a bad name among some economists and most investors.However,from a stock market perspective,deflations’bad name may not be well-deserved.Several observations support this:1)The 1930s was a statistical outlier and not representative for a deflationary period and deflation does not seem to create recessions,causality goes the other way;2)real stock returns are positive and around average in the periods leading up to and following the onset of deflation;3)when moving from low inflation to mild deflation,P/E ratios are virtually unchanged;and 4)peak P/E ratios seem to be reached at inflation rates close to zero.The author proposes three possible explanations for the seemingly disconnect between the empirical data and the“default”ex ante belief of most economists and investors:availability heurist,deflation illusion,and tax related issues in connection with the tax hypothesis.

A simple analytical method for deflation prediction of inflatable structures

The static performance of inflatable structures has been well studied and the dynamic deployment simulation has received much attention. However, very few studies focus on its deflation behavior. Although there are several dynamic finite element algorithms that can be applied to the deflation simulation, their computation costs are expensive, especially for large scale structures. In this work, a simple method based on classic thermodynamics and the analytical relationship between air and membrane was proposed to efficiently analyze the air state variables under the condition of ventilation. Combined with failure analysis of static bearing capacity, a fast incremental analytical method was presented to predict both elastic and post wrinkling deflation process of inflatable structures. Comparisons between simplified analysis, dynamic finite element simulation, and a full-scale experimental test are presented and the suitability of this simple method for solving the air state and predicting the deflation behavior of inflatable structures is proved.

U.S.,not China, is culprit of global deflation, inflation

This paper is an outcome of comprehensive and systematic research on whether China exports deflation and inflation using the newly developed DAG technique. Our results indicate that in the international transmission of inflation, the United States, as the world's largest economy, plays a dominant role. In contrast, during both deflation and inflation periods, China has a minimal impact on the price levels of major trading partners. Thus China is not to be blamed for global deflation or inflation. This research has made use of DAG and some other techniques to yield reliable and reasonable conclusions.

靶肺段萎陷法在单孔胸腔镜联合肺段切除术中的应用

目的:探讨靶肺段萎陷法在单孔胸腔镜联合肺段切除术中的应用。方法:回顾性分析从2020年1月-2022年1月我院15例联合肺段切除的肺癌患者临床资料,术中均采用靶肺段萎陷法显示段间平面,即先游离夹闭保留肺段的动脉;再充分膨胀肺组织;然后等待肺组织自然萎陷至出现膨胀-萎陷界线,标记段间平面;最后松开夹闭的动脉,分离切断靶肺段的动脉、支气管、段内静脉和段间平面。结果:15例患者术后无持续性漏气发生,无术后并发症发生,手术时间、术后平均住院时间和胸腔引流管留置时间相较同期传统的肺段切除患者相比,均无明显差异(P>0.05)。结论:靶肺段萎陷法是一种简单、安全而有效的段间平面确定方法,尤其适用于联合肺段切除的手术。

基于改进YOLOv3的机场盲区遥感图像目标检测方法

针对机场存在的雷达监视盲区问题,提出一种改进YOLOv3目标检测算法。首先,基于原YOLOv3主干特征提取网络加入SPP池化模块,以深度可分离卷积替代普通卷积。然后,针对小尺度目标数据集,增加第4层金字塔加强特征提取网络,在kmeans++聚类算法的基础上提出一种线性放缩进行锚框筛选。最后,在RSOD-Dataset数据集上MAP为88.82%,FPS为37.57。仿真结果表明该方法可以满足机场实时目标检测任务的需求。

基于上下文模型的超长哈夫曼码校正算法

常见的Gzip、Zlib数据压缩标准都采用Deflate协议压缩封装数据,Deflate协议中采用哈夫曼码编码源符号(Source symbols)。哈夫曼编码算法通过构建哈夫曼树生成哈夫曼码,Deflate协议限定源符号的哈夫曼码的码长不能超过最大值。源符号的哈夫曼码长最大值等于哈夫曼树的高度,因此当哈夫曼树的高度超过限定值时,需要先把哈夫曼树进行“校正”,随后再为每个符号分配。Gzip、Zlib软件参考代码中使用的基于二叉树搜索的“校正”算法,校正时需要遍历搜索哈夫曼树,寻找嫁接“节点”。校正流程时间消耗非常大,而且硬件实现难度较大。该文探索一种基于上下文模型校正超长哈夫曼树的算法,与参考二叉树搜索算法相比:该算法可以快速校正超长哈夫曼树,将校正的时间消耗降至为0,而且对压缩效果几乎没有影响(压缩比平均下降率仅为0.372%)。该算法也易于硬件化实现,可以实时校正超长哈夫曼码。