铱催化C—H键活化硼化及其转化合成聚三氟苯乙烯衍生物

在1,5-环辛二烯氯化铱(I)二聚体(［IrCl(COD)］2)和4,4′-二叔丁基-2,2’-联吡啶（dtbpy）的催化作用下,成功实现了聚三氟苯乙烯（PTFS）的C—H键活化硼化反应。通过调节联硼酸频那醇酯与PTFS中重复单元的物质的量之比,可以有效地控制PTFS中硼酸酯基团的含量。然后通过聚三氟苯乙烯(PTFS-Bpin)与含羰基或砜基的溴代芳烃间的Suzuki-Miyaura偶联反应,将含羰基或砜基的芳基侧链引入到PTFS中。采用核磁共振（1H-NMR、11B-NMR和13C-NMR）、凝胶渗透色谱（GPC）、差示扫描量热分析（DSC）和热重分析（TG）等测试分析了聚合物的结构和性质。结果表明：经硼化及偶联反应修饰后的PTFS具有良好的溶解性和热稳定性,硼酸酯官能团的存在为向PTFS中进一步引入其他功能性侧链提供了可能。     

Use and Misuse of Multivariable Approaches in Interventional Cardiology Studies on Drug‐Eluting Stents: A Systematic Review

Aims: Randomized clinical trials (RCTs) are the most reliable evidence, even if they require important resource and logistic efforts. Large, cost‐free and real‐world datasets may be easily accessed yielding to observational studies, but such analyses often lead to problematic results in the absence of careful methods, especially from a statistic point of view. We aimed to appraise the performance of current multivariable approaches in the estimation of causal treatment and effects in studies focusing on drug‐eluting stents (DES). Methods and Results: Pertinent studies published in the literature were searched, selected, abstracted, and appraised for quality and validity features. Six studies with a logistic regression were included, all of them reporting more than 10 events for covariates and different length of follow‐up, with an overall low risk of bias. Most of the 15 studies with a Cox proportional hazard analysis had a different follow‐up, with less than 10 events for covariates, yielding an overall low or moderate risk of bias. Sixteen studies with propensity score were included: the most frequent method for variable selection was logistic regression, with underlying differences in follow‐up and less than 10 events for covariate in most of them. Most frequently, calibration appraisal was not reported in the studies, on the contrary of discrimination appraisal, which was more frequently performed. In seventeen studies with propensity and matching, the latter was most commonly performed with a nearest neighbor‐matching algorithm yet without appraisal in most of the studies of calibration or discrimination. Balance was evaluated in 46% of the studies, being obtained for all variables in 48% of them. Conclusions: Better exploitation and methodological appraisal of multivariable analysis is needed to improve the clinical and research impact and reliability of nonrandomized studies. (J Interven Cardiol 2012;25:611–621)     

Dual Epicardial Ventricular Tachycardia: A Tale of Two VTs

A young female with isolated ventricular noncompaction and acute myocarditis presented with incessant dual epicardial ventricular tachycardia consisting of a manifest reentrant circuit and a shorter cycle length concealed circuit. A single radiofrequency terminated both tachycardias. (PACE 2012; 35:e1–e5)     

Improving the Oral Bioavailability of Sulpiride by a Gastric-retained Form in Rabbits

To improve the limited oral bioavailability of sulpiride, a gastric-retained form was developed and evaluated using gastric-emptying-controlled rabbits. The AUC value after oral administration of sulpiride as an aqueous solution was less than that after oral administration of sulpiride original powder. The dissolution was not important as a rate limiting factor for sulpiride oral absorption. Sulpiride was absorbed predominantly from the upper part of the small intestine of the rabbit. A gastric-retained tablet prepared from Carbopol 934P, with sustained-release characteristics, was found to be suitable for improving and extending the oral bioavailability of sulpiride.