Objective To investigate the mechanism of chaos during ventricular fibrillation(VF)after acute myocardial infarction(AMI)and observe the property of nonlinear dynamics of VF in order to provide clinical doctors with theory evidences to prevent VF after AMI.Methods From Jun.2003 to Dec.2005,we made the acute myocardial infacrtion model and induced VF of canine in vivo by using rapid pacing,and recorded the cardiac electrophysiological parameters by using 64-trains multi-polar epicardial-mapping electrocardiogram system to observe the change of the cycle length(CL)of ventricular arrhythmia in the Second Affiliated Hospital of China Medical Univercity.Results The pacing interval of VF in acute ischemia myocardium had been significantly increased; the cycle length(CL)showed the spatiotemporal complexity,such as period doubling bifurcation and quasiperiodicity and its Poincar'e plots formed a ring-like structure meaning nonlinear dynamics property during VF.Conclusion The liminal value of VF has been significantly increased during acute myocardial infarction.VF is induced by system come-into period doubling bifurcation,quasiperiodicity and chaos.

OBJECTIVE:To systematically evaluate therapeutic efficacy and safety of Yupingfeng powder in adjavant therapy of allergic rhinitis,and to provide evidence-based reference for clinical treatment. METHODS:Retrieved from Wanfang database,VIP,CJFD,CBM,Cochrane Library,EMBase and PubMed,RCTs about Yupingfeng powder combined with chemical medicine (trial group)vs. chemical medicine alone in the treatment of allergic rhinitis were collected. Meta-analysis was conducted by using Rev Man 5.2 statistical software after data extraction and quality evaluation according to Cochrane system evaluation method 5.1.0. RESULTS:A total of 15 RCTs were included,invovling 1366 patients. The results of Meta analysis showed that response rate [OR=3.95,95%CI(2.80,5.58),P<0.001],recurrence rate [OR=0.37,95%CI(0.22,0.63),P<0.001] and the incidence of ADR [OR=0.15,95%CI(0.06,0.35),P<0.001] in trial group were significantly higher than control group,with statistical significance. CONCLUSIONS:Yupingfeng powder in adjuvant therapy of allergic rhinitis show good therapeutic efficacy and can reduce recur-rence rate with good safety.