Influence of efflux pump inhibitors on the multidrug resistance of Helicobacter pylori

AIM:To evaluate the effect of efflux pump inhibitors (EPIs) on multidrug resistance of Helicobacter pylori (H. pylori).METHODS: H. pylori strains were isolated and cultured on Brucella agar plates with 10% sheep's blood. The multidrug resistant (MDR) H. pylori were obtained with the inducer chloramphenicol by repeated doubling of the concentration until no colony was seen, then the susceptibilities of the MDR strains and their parents to 9 antibiotics were assessed with agar dilution tests. The present study included periods before and after the advent of the EPIs, carbonyl cyanide m-chlorophenyl hydrazone (CCCP), reserpine and pantoprazole), and the minimum inhibitory concentrations (MICs) were determined accordingly. In the same way, the effects of 5 proton pump inhibitors (PPIs), used in treatment of H. pylori infection, on MICs of antibiotics were evaluated.RESULTS: Four strains of MDR H. pylori were induced successfully, and the antibiotic susceptibilities of MDR strains were partly restored by CCCP and pantoprazole, but there was little effect of reserpine. Rabeprazole was the most effective of the 5 PPIs which could decrease the MICs of antibiotics for MDR H. pylori significantly.CONCLUSION: In vitro, some EPIs can strengthen the activities of different antibiotics which are the putative substrates of the efflux pump system in H. pylori.

阻聚剂在乳液聚合中的行为(Ⅰ)——第Ⅱ类动力学体系(?=0.5)

本文研究了水溶性和油溶性阻聚剂对第Ⅱ类动力学乳液聚合的影响(以苯乙烯乳液聚合为例).实验结果表明阻聚剂对胶粒的形成及增长有明显的影响.推导出反映这些影响的数学模型,并对阻聚剂的影响进行了模拟研究,指出阻聚剂的这些行为在工业乳液聚合中的严重性.

知证卫生决策工具之十八--制定政策监测和评估计划

"监测"一词常用于描述这样的过程,即系统地收集数据以告知决策者、管理者及其他利益相关者一项新政策或规划的实施是否符合其预期。出于监测的目的而使用指标作出相关判断,如是否达到预期目标,或是否恰当地使用所分配的资金。有时"评估"一词可与"监测"一词互换,但前者常更强调结果的获得。当使用"效果评估"一词时,常指特别尝试设法去确定观察到的结果变化是否可归因于特定的政策或规划。我们在本文中提出能用于指导政策或规划监测与评估的四个问题:①是否有必要监测?②应测量什么?③是否应开展效果评估?④如何进行效果评估?

极化液输注对急性ST段抬高心肌梗死患者死亡率的影响:CREATE-ECLA随机对照试验

Context: Glucose-insulin-potassium(GIK) infusion is a widely applicable, low-cost therapy that has been postulated to improve mortality in patients with acute ST segment elevation myocardial infarction(STEMI). Given the potential global importance of GIK infusion, a large, adequately powered randomized trial is required to determine the effect of GIK on mortality in patients with STEMI. Objective: To determine the effect of high-dose GIK infusion on mortality in patients with STEMI. Design, Setting, and Participants: Randomized controlled trial conducted in 470 centers worldwide among 20201 patients with STEMI who presented within 12 hours of symptom onset. The mean age of patients was 58.6 years, and evidence based therapies were commonly used. Intervention: Patients were randomly assigned to receive GIK intravenous infusion for 24 hours plus usual care(n=10091) or to receive usual care alone(controls; n=10110). Main Outcome Measures: Mortality, cardiac arrest, cardiogenic shock, and reinfarction at 30 days after randomization. Results: At 30 days, 976 control patients(9.7%) and 1004 GIK infusion patients(10.0%) died(hazard ratio [HR], 1.03; 95%confidence interval [CI], 0.95-1.13; P=.45)-. There were no significant differences in the rates of cardiac arrest(1.5%[151/10107] in control and 1.4%[139/10088] in GIK infusion; HR, 0.93; 95%CI, 0.74-1.17; P=.51), cardiogenic shock(6.3%[640/10107] vs 6.6%[667/10088]; HR, 1.05; 95%CI, 0.94-1.17; P=.38), or reinfarction(2.4%[246/10107] vs 2.3%[236/10088]-; HR, 0.98; 95%CI, 0.82-1.17; P=.81). The rates of heart failure at 7 days after randomization were also similar between the groups(16.9%[1711/10107] vs 17.1%[1721/ 10088]; HR, 1.01; 95%CI, 0,95-1.08; P=.72). The lack of benefit of GIK infusion on mortality was consistent in prespecified subgroups, including in those with and without diabetes, in those presenting with and without heart failure, in those presenting early and later after symptom onset, and in those receiving and not receiving reperfusion therapy(thrombolysis or primary percutaneous coronary intervention). Conclusion: In this large, international randomized trial, high-dose GIK infusion had a neutral effect on mortality, cardiac arrest, and cardiogenic shock in patients with acute STEMI.

阻聚剂在乳液聚合中的行为(Ⅱ)——第Ⅰ类动力学体系?〈〈 0.5)

本文研究了水溶性阻聚剂(O_2)和油溶性阻聚剂(TBC)在第I类动力学乳液聚合体系(以醋酸乙烯乳液聚合为例)中的行为,它与第Ⅱ类动力学的乳液聚合有较大的差别.对油溶性阻聚剂的影响进行了数学模拟,模拟结果与实验结果比较吻合.

BEHAVIOUR OF INHIBITORS IN EMULSION POLYMERIZATION(Ⅰ)CaseⅡKinetics

The behaviour of water soluble and monomer soluble inhibitors in emulsion polymerization of monomersfollowing Case Ⅱ kinetics(e.g.styrene)has been investigated.Experimental studies reveal that inhibitors canhave an appreciable effect on both polymer particle nucleation and growth.A mathematical model showingthese effects has been developed and simulation studies have been done.The simulation results imply that theconsequences of these effects of monomer soluble inhibitors for industrial emulsion polymerization may be quiteserious.

Relative Contributions of Intraoperative Low Dose Ketamine, Lidocaine and Ketamine-Lidocaine Combination in Addition to Intrathecal Morphine for Postoperative Analgesia in Open Liver Resection: A Prospective, Randomized, Four-Arm, Triple Blind, Placebo-Controlled Trial

Background and Aims: Open liver resection requiring an upper abdominal incision is associated with significant opioid use due to postoperative pain. We tested the hypothesis that the intraoperative combination of low dose lidocaine and ketamine would reduce opioid consumption when given in conjunction with intrathecal morphine for liver resection surgery. Methods: In this triple blind, parallel group four-arm placebo-controlled trial, we randomized 124 adult ASA 2 - 4 liver resection patients to receive intraoperative lidocaine 0.33 mg/kg/h (group L), ketamine 70 μg/kg/h (group K), combination of lidocaine 0.33 mg/kg/h and ketamine 70 μg/kg/h (group KL) and saline (group P). All patients received 300 μg intrathecal morphine prior to induction of anesthesia. All infusions were started immediately after intubation and continued until the end of surgery. Primary outcome measurements included opioid consumption at 24-hours. Secondary outcomes included pain scores, opioid consumption at 48 and 72-hours and side effects including nausea, vomiting, dizziness, hallucinations, headaches and signs of local anaesthetic toxicity. Patients were followed up for 12 weeks. Results: There was no difference in the primary outcome of opioid consumption within all 4 groups at rest or movement at 24-hours. Secondary outcome of 48-hour rest pain score was significantly higher in the L group (p = 0.03) but without any difference in opioid use. There was no difference in any other outcomes between the groups at any time points. Conclusions: Low dose lidocaine and its combination with ketamine did not add any analgesic/morphine sparing benefit in the presence of single dose intrathecal morphine in patients with major liver resection.

BEHAVIOUR OF INHIBITORS IN EMULSION POLYMERIZATION(Ⅱ)CaseⅠKinetics

The behaviour of water soluble and monomer soluble inhibitors in the emulsion polymerization for CaseI system(e.g.vinyl acetate and vinyl chloride)has been studied.The behaviour of monomer soluble inhibitorsis shown to be quite different from that observed in Case Ⅱ emulsion polymerization system.Model predictionsof the effect of these inhibitors on polymer particle nucleation and growth rate are shown to be in satisfactoryagreement with experimental results.

用光纤光栅测量材料的热膨胀系数

提出了一种利用光纤光栅来测量物质热膨胀系数的新方法。光纤光栅被固定在待测的样品上。测量的原理是基于光纤光栅的温度和应力特性。测量精度达到0.21×10-7/℃。而且测量过程非常简单和易于实现。

L波段掺铒光纤放大器的增益平坦滤波器设计

EDFA的增益平坦化是WDM系统中的重要问题 ,用成本低、插损小的光纤光栅实现该功能是一项有吸引力的方案 ,采用剥层法设计了基于啁啾光栅的增益平坦滤波器。基于时间因果律的剥层算法将光纤光栅看成一个分离的模型 ,由一系列长度为Δ的复反射器所组成 ,每个反射器的后端耦合系数都可由它的前端耦合系数递归地求出 ,从而能快速、精确地反演出光栅的耦合系数函数。啁啾光栅的目标反射谱由理想的增益平坦滤波器透射谱获得 ,利用与反射谱群时延有关的常数α可控制光栅的长度 ,α取值为 0 0 0 2 4cm2 时 ,对应的光栅长度为 3 5cm。用剥层法反演出耦合系数函数后 ,又通过解Riccati方程模拟了合成光栅的透射谱。数值模拟结果显示理想透射谱与合成光栅透射谱之间的峰峰值误差小于 0 1dB ,并且在工作带宽范围内 ,透射谱群时延的变化量小于 0 6 ps ,表明该滤波器对系统没有额外的色散影响。

弱非周期性相位取样啁啾光栅的优化方法

取样光栅可以同时对多个信道进行滤波或色散补偿 ,所以在波分复用 (WDM)系统中有广泛的应用 ,其中周期相位取样光栅是一种很有前途的设计方法 ,但周期取样的方法会使取样光栅的所有信道具有相同的色散补偿能力。提出设计弱非周期性相位取样啁啾光栅的优化方法 ,通过引入一组与信道色散补偿量有关的啁啾控制参数 ,可使不同信道的色散补偿量存在差异。运用该方法设计出弱非周期的取样光栅后 ,可用传输矩阵法来模拟该光栅的复反射谱 ,结果显示通过调整啁啾控制参数 ,可方便地控制不同信道的色散补偿能力 ,从而能实现对光纤链路色散与色散斜率的同时补偿 ,而且取样函数的幅度值的起伏则被完全消除。