Numerical and Experimental Research on Convergence Angle of Wet Sprayer Nozzle

Shotcrete is a popular support method in construction of both ground projects and underground projects, such as tunnels, subways, slopes and roadway, etc. However, at present researches on the influence of nozzle structure parameters on the performance of concrete injection are insufficient. This research focuses on the influence of various parameters of nozzle structure on the evenness and dust generating, and conducts a systematic study on the flow characteristics of the concrete in the nozzle of wet spraying machinery and the quality control law, through a comprehensive research method combining theoretical analysis, numerical simulation and field tests. On the basis of dynamic analysis of the internal flow field of the nozzle, the mathematical model and numerical model of the internal flow field of the nozzle are establishes. Then the simulation calculation of the flow field of the wet spray nozzle is conducted with the FLUENT® software. The fluid’s contour about velocity and phase volume fraction in the nozzle were obtained. On this basis this paper analyzed each phase’s volume fraction of the mixed fluid in the outlet section. The convergent section of the nozzle is tested in the spray concrete impact force distribution system. The results are in good correspondence with the results of theoretical analysis and numerical simulation, which verifies the validity and reliability of the conclusion of numerical simulation. This paper provides the basis for the optimization of nozzle structure, and the improvement of the sprayed concrete construction quality

Development of the Risk Management Mechanism of an Enterprise Resource Planning System based on Work System Method

This study collects 24 risk-management-relevant research papers published between 2000 and 2010 to elicit significant risk factors and thus develop the risk management mechanism of an enterprise resource planning (ERP) system. The study adopts the grounded theory and conducts an expert questionnaire in order to report its findings on 49 risk factors. Based on the work system method, the identified factors are classified into nine categories and a risk management mechanism is developed thereafter. Finally, to examine the feasibility of the mechanism, two case studies are further investigated. The developed mechanism is found to be a convenient, quick, and proper ERP system risk management tool that can assist enterprises in identifying, analyzing, assessing, and responding to potential risks

HIF-1α Contributes to Hypoxia-induced Invasion and Metastasis of Esophageal Carcinoma via Inhibiting E-cadherin and Promoting MMP-2 Expression

Hypoxia-inducible factor-1α (HIF-1α) has been found to enhance tumor invasion and metastasis, but no study has reported its action in esophageal carcinoma. The goal of this study was to explore the probable mechanism of HIF-1α in the invasion and metastasis of esophageal carcinoma Eca109 cells in vitro and in vivo. mRNA and protein expression of HIF-1α, E-cadherin and matrix metalloproteinase-2 (MMP-2) under hypoxia were detected by RT-PCR and Western blotting. The effects of silencing HIF-1α on E-cadherin, MMP-2 mRNA and protein expression under hypoxia or normoxia were detected by RT-PCR and Western blotting, respectively. The invasive ability of Eca109 cells was tested using a transwell chambers. We established an Eca109-implanted tumor model and observed tumor growth and lymph node metastasis. The expression of HIF-1α, E-cadherin and MMP-2 in xenograft tumors was detected by Western blotting. After exposure to hypoxia, HIF-1α protein was up-regulated, both mRNA and protein levels of E-cadherin were down-regulated and MMP-2 was up-regulated, while HIF-1α mRNA showed no significant change. SiRNA could block HIF-1α effectively, increase E-cadherin expression and inhibit MMP-2 expression. The number of invading cells decreased after HIF-1α was silenced. Meanwhile, the tumor volume was much smaller, and the metastatic rate of lymph nodes and the positive rate were lower in vivo. Our observations suggest that HIF-1α inhibition might be an effective strategy to weaken invasion and metastasis in the esophageal carcinoma Eca109 cell line

Prevalence and molecular characterization of plasmidmediated beta-lactamase genes among nosocomial Staphylococcus aureus isolated in Taiwan

Purpose: To analyze the drug susceptibility phenotypes and the patterns of plasmid-mediated β- lactamase genes among nosocomial Staphylococcus aureus drug resistance isolates in Taiwan.Methods: The antibiotic susceptibilities of 617 clinical Staphylococcus aureus isolates collected from 2005 - 2009 from Chiayi Christian Hospital (Chiayi, Taiwan) were examined in vitro against 8 antimicrobial agents using agar diffusion method. Among the clinical isolates, 114 strains of methicillinsensitive Staphylococcus aureus and 45 strains of methicillin-resistant Staphylococcus aureus (MRSA) isolates were selected for plasmid profile analysis. The patterns of β-lactamase genes presented in plasmids were investigated by polymerase chain reaction analysis.Results: Most test strains were resistant to multiple antibiotics, particularly for the traditional agents such as ampicillin, penicillin, cephalexin and kanamycin. Plasmid profile analysis revealed that up to 36 % of the clinical strains harbored plasmids and were able to develop multi-drug resistant. Among them, most of the isolates harbored at least one plasmid (range 1 – 7) with a size range of 2.3 to 23 Kb. Among the several types of β-lactamases, blaTEM was the most prevalent.Conclusion: The results obtained from this study can serve as a valuable reference for the future control for clinical antibiotic resistant strains and more thorough discussions on resistance mechanisms.Keywords: Staphylococcus aureus, Antibiotic susceptibility, Nosocomial pathogens, Plasmid profile, β- lactamase

Report on grade assessment situation of the 12 prevention and control center pilot in Sichuan Province

目的  了解疾病预防控制机构（简称疾控机构）能力建设、经费保障、运行管理等情况，探索全省疾控等级评审方法和程序。方法  组织专家按照统一的评审标准对12家试点单位在政策环境、基础条件、疾病预防控制、检验检测、健康危害相关因素、信息化建设等7大类38个指标167个参数进行现场评审。结果  机构得分最高是自贡市，考核内容得分率较低的是检验检测和健康危害因素监测与控制，创建过程中各级政府对疾控机构在人、财、物方面均有不同程度的投入，A类和B类项目开展率有所增加，制定了疾控机构三级两等的评审标准。结论  疾控机构等级评审是疾控机构标准化建设和发展的有力抓手，通过评审能发现短板、弥补不足，增强政府在卫生防病方面的主体责任意识。Objective: To understand the situation of ability construction, funds guarantee, operation management of disease control agency, trying to figure out assessment method and program for prevention and control center. Methods: According to the unified standard, evaluation experts were organized to evaluate 12 pilot units. The assessment include 7 categories, 38 indicators and 167 parameters:  the policy environment, basic conditions, disease prevention and control, inspection, health relative factors, information construction, etc. Results: Zigong scored highest in all instituions. Inspection and health hazards monitoring and control scored lower in all categories.  In the process of setting up, all levels of government have different input on personnel, property and goods to prevention and control center. The development rate of type A and type B project increased. The classification standards were produced. Conclusion: Grade assessment is important to construction and development standardization of disease control agency. The assessment can find the weakness, make up the deficiency, strengthen responsibility consciousness of the government

Cardiac troponin and C-reactive protein for predicting all-cause and cardiovascular mortality in patients with chronic kidney disease: A meta-analysis

Elevated serum levels of cardiac troponin and C-reactive protein are associated with all-cause and cardiovascular mortality in patients with end-stage renal disease. However, the relationship between these two biomarker levels and mortality in patients with chronic kidney disease remains unclear. We conducted a meta-analysis to quantify the association of cardiac troponin and C-reactive protein levels with all-cause and cardiovascular mortality in patients with chronic kidney disease. Relevant studies were identified by searching the MEDLINE database through November 2013. Studies were included in the meta-analysis if they reported the long-term all-cause or cardiovascular mortality of chronic kidney disease patients with abnormally elevated serum levels of cardiac troponin or C-reactive protein. Summary estimates of association were obtained using a random-effects model. Thirty-two studies met our inclusion criteria. From the pooled analysis, cardiac troponin and C-reactive protein were significantly associated with all-cause (HR 2.93, 95% CI 1.97-4.33 and HR 1.21, 95% CI 1.14-1.29, respectively) and cardiovascular (HR 3.27, 95% CI 1.67-6.41 and HR 1.19, 95% CI 1.10-1.28, respectively) mortality. In the subgroup analysis of cardiac troponin and C-reactive protein, significant heterogeneities were found among the subgroups of population for renal replacement therapy and for the proportion of smokers and the C-reactive protein analysis method. Elevated serum levels of cardiac troponin and C-reactive protein are significant associated with higher risks of all-cause and cardiovascular mortality in patients with chronic kidney disease. Further studies are warranted to explore the risk stratification in chronic kidney disease patients