CASE-CONTROL STUDY FOR HOSPITAL INFECTIONS CAUSED BY GRAM-NEGATIVE BACILLI IN EMERGENCY INTENSIVE CARE UNIT

Objective To evaluate the potential patient factors associated with hospital infections caused by gram-negative bacilli in Emergency Intensive Care Unit(EICU).Methods A total of 146 patients with hospital infections were investigated.The method of retrospective case-control study and multivariable logistic regression analysis were adopted.Results Univariate analysis revealed relationship among numerous patient factors,and multivariate analysis revealed four factors to be associated independently with hospital infections caused by gram-negative bacilli:mechanical ventilation,corticoid use, length of stay,and coma.Conclusion The comprehensive preventive measures should be taken to deal with the risk factor of hospital infections in EICU.     

Numerical prediction of the modal response of flexible cylinders in cross-flow with a current dependent form of damping

A quadratic eigenvalue problem (QEP) was posed in order to study the dynamics of flexible cylinders in cross-flow, simulating slender offshore structures such as risers, catenaries or tendons. The Euler–Bernoulli equation was used to model the structure assuming a fluid loading model, and yielding a quadratic eigenvalue problem that included a form of damping dependent not only on the structural damping itself, but also on the free stream velocity and the fluid force coefficients. We solved the QEP using the finite element method. We also derived a simplified analytical solution in this work for comparison with the QEP, however this solution does not consider changes in tension along the length of the cylinder as the QEP does. In our study, the QEP solutions were first validated against the simplified analytical solution, and also against a well-known experimental dataset obtained in 2003, in which a flexible circular cylinder model was used to model the dynamics of a riser undergoing multi-mode vortex-induced vibrations.     

Biological Status Assessment of Coral Reefs in Southern Puerto Rico: Supporting Coral Reef Protection Under the U.S. Clean Water Act

Abstract

States and other jurisdictions may protect coral reefs using biological water quality standards outlined by the United States Clean Water Act (CWA). Such protection will require long-term, regional monitoring of the resource using biological indicators and a probability-based sampling design. A 60-station survey targeting nearshore linear coral reef was conducted across southern Puerto Rico in December 2011 to document the status of reef inhabitants using a probabilistic, regional sampling design. The quantity, type and condition of stony corals, fish, gorgonians, and sponges were documented from each station, providing a robust representation of linear reef status and composition across the region. Fish represented 106 unique taxa and stony corals 32 unique taxa. Benthic organisms (stony corals, sponges, and gorgonians) averaged nearly 12 colonies per square meter, more than half of which were gorgonians. Assessment results can be used as a baseline to compare with future regional surveys to quantify change in reef condition over time (trend). Both temporal and spatial changes can be expected after large-scale disturbances like hurricanes Maria and Irma in 2017. The indicators and probabilistic sampling design support the long-term regional monitoring envisioned by the Environmental Protection Agency to implement CWA protections in Puerto Rico and elsewhere.     

Impact of Everyday Weather on Individual Daily Travel Behaviours in Perspective: A Literature Review

Despite the hundreds of billions of dollars being spent on infrastructure development -- from roads, rail and airports to energy extraction and power networks to the Internet -- surprisingly little reliable knowledge exists about the performance of these investments in terms of actual costs, benefits and risks. This paper presents results from the first statistically significant study of cost performance in transport infrastructure projects. The sample used is the largest of its kind, covering 258 projects in 20 nations worth approximately US$90 billion (constant 1995 prices). The paper shows with overwhelming statistical significance that in terms of costs transport infrastructure projects do not perform as promised. The conclusion is tested for different project types, different geographical regions and different historical periods. Substantial cost escalation is the rule rather than the exception. For rail, average cost escalation is 45% (SD=38), for fixed links (tunnels and bridges) it is 34% (62) and for roads 20% (30). Cost escalation appears a global phenomenon, existing across 20 nations on five continents. Cost estimates have not improved and cost escalation not decreased over the past 70 years. Cost estimates used in decision-making for transport infrastructure development are highly, systematically and significantly misleading. Large cost escalations combined with large standard deviations translate into large financial risks. However, such risks are typically ignored or underplayed in decision-making, to the detriment of social and economic welfare.     

自体肝镰状韧带补片加固法在胰肠吻合术中的应用

目的介绍利用自体肝镰状韧带补片加固胰肠吻合的方法和经验。方法自2010年6月至2011年7月对6例质地脆弱的胰腺残端,术中利用自体肝镰状韧带制成补片加固行胰肠吻合,观察术后并发症发生及腹腔引流液情况。结果 6例患者均顺利完成手术,术后无严重并发症,无胰肠吻合口漏。结论肝镰状韧带补片加固法取材容易,操作简单,效果可靠,对于质地脆弱的胰腺是一种可供选择的方法。     

A proposal for cost-related and market-oriented train running charges

This paper examines some key aspects of a charging system for promoting railway transport, including charges reflecting a clear relationship with costs (transparency) and charges reflecting the quality of the infrastructure manager's service. Train running charges recover track-related costs and can help to develop a charging system that meets these requirements. To orient train running charges to the market, a method for processing track maintenance and renewal costs is proposed whereby the quality of the service provided by an infrastructure is measured according to its utility to the railway undertaking. To achieve transparency, a single indicator is used for cost planning and the subsequent levying of costs on railway undertakings. The paper includes an example of how proposed train running charges would be calculated according to data from 14 European countries. The example shows that short-distance trains generate the lowest maintenance and renewal costs, followed by long-distance trains and freight trains.     

基于区间分析的发动机悬置系统稳健优化设计

针对不确定参数发动机悬置系统的优化问题,基于区间分析理论,将稳健设计与多目标优化相结合,提出一种提高发动机悬置系统隔振性能的稳健优化设计方法。该方法在区间数学模型的基础上建立悬置系统稳健优化模型,以动反力及其变化范围最小为目标函数,固有频率的合理配置为约束条件,悬置刚度为优化变量,并将悬置刚度和悬置位置的波动范围作为区间参数变量,对某型轿车发动机悬置系统进行稳健优化设计。结果表明,该方法改善了悬置系统的隔振性能,提高了系统参数的稳健性。     

风挡玻璃对车身结构刚度影响的研究

首先研究白车身(BIW)和带有风挡玻璃的车身结构(BIP)的有限元模型的构建技术,进而分析了风挡玻璃对车身结构静弯曲刚度和静扭转刚度的影响。接着,通过对BIW和BIP车身结构进行固有振动特性分析,揭示了风挡玻璃对车身结构动刚度的影响。最后,对车身结构的接头刚度性能进行了分析和评价,并总结了风挡玻璃对车身接头结构承载特性的影响规律。     

Review on characterization of nano-particle emissions and PM morphology from internal combustion engines: Part 1

This paper is review of the characterization of exhaust particles from state-of-the-art internal combustion engines. We primarily focus on identifying the physical and chemical properties of nano-particles, i.e., the concentration, size distribution, and particulate matter (PM) morphology. Stringent emissions regulations of the Euro 6 and the LEV III require a substantial reduction in the PM emissions from vehicles, and improvements in human health effects. Advances in powertrains with sophisticated engine control strategies and engine after-treatment technologies have significantly improved PM emission levels, motivating the development of new particle measurement instruments and chemical analysis procedures. In this paper, recent research trends are reviewed for physical and chemical PM characterization methods for gasoline and diesel fueled engines under various vehicle certification cycles and real-world driving conditions. The effects of engine technologies, fuels, and engine lubricant oils on exhaust PM morphology and compositions are also discussed.     

Impact technique for measuring global dynamic stiffness of engine mounts

Engine mounts are used for engine vibration isolation. The dynamic performance of the mount depends on the orientation. Measurements of the dynamic properties of engine mounts are usually performed in the axial direction because of the problem related to actuator loading direction and set up costs. Impact technique is developed here to measure the dynamic driving point stiffness and driving point shear stiffness of engine mount in a single setup. The compressive and shear frequency-dependent stiffnesses are obtained in the vertical orientation. A transformation matrix is used to calculate the frequency-dependent stiffnesses and loss factors in other orientations. Three different designs of engine mounts are used to verify the accuracy of the transformation model. The correlation coefficient between calculation and measurement results show R²≥ 0.995 along the X- and Y-axes. For the Z-axis, mounts B and C showed R²≥ 0.95 and mount A 0.687 ≤ R²≤ 0.791.