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@#新型冠状病毒（2019 novel coronavirus，SARS-CoV-2）感染现已被纳入《中华人民共和国传染病防护法》规定的乙类传染病，并采取甲类传染病预防控制措施。
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The association between atrial fibrillation (AF) after coronary artery bypass grafting (CABG) and the surgical techniques selected has been extensively reported.However,no consistent results were obtained.In the present study,a meta-analysis was conducted by searching the electronic databases PubMed,Embase,Web of Science,and Cochrane to identify the association of post-CABG AF with on-pump (conventional CABG,cCABG) or off-pump CABG (OPCABG).Outcomes from randomized clinical trials (RCTs) and propensity score matching (PSM) trials were pooled by using the fixed-effect or the random-effect modeling method,and verified by the quality-effect modeling method.There were 35 studies with 36 independent reports that met the inclusion criteria and were eventually included in our meta-analysis.The total odds ratio (OR) of the incidence of post-CABG AF between OPCABG and cCABG was 0.80 (95％ CI 0.71-0.91).The 25 randomized clinical trials (RCTs) had an OR of 0.69 (95％ CI 0.56-0.86),while the OR of the 11 PSM trials was 0.88 (95％ CI 0.77-1.00).Twenty-six studies involving the patients at a mean age no more than 65 years showed an OR of 0.76 (95％ CI 0.64-0.90),whereas 10 studies with patients greater than 65 years old showed an OR of 0.90 (95％ CI 0.78-1.05).The results of this meta-analysis suggest that OPCAB surgery may reduce the incidence of post-CABG AF when compared to cCABG and that younger patients may benefit more from OPCAB and have a lower incidence ofpost-CABG AF.
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Autonomic nervous system activation can result in significant changes of atrial electrophysiology and facilitate induction of atrial fibrillation.By recording influence of different concentrations of acetylcholine (ACh) on atrial fibers (AF),we investigated the role of the increased vagal tone in electrical remodeling in atrial fibrillation.Parameters of action potentials and force contraction (Fc) in atrial fibers were recorded by using standard intracellular microelectrode technique and force transducer.It was found that:(1) ACh at 0.1 μmol/L had no significant influence on spontaneous action potentials (SAPs) and Fc (n=6,P＞0.05); ACh at both 1.0 and 10.0 μmol/L shortened action potential duration (APD) and Fc of human AF from right atrium (n=6,P＜0.05); there was no significant difference in shortening APD between 10.0 and 1.0 μmol/L of ACh; (2) ACh at 0.1 μmol/L had no significant desensitization (n=6,P＞0.05),but ACh at 1.0 and 10.0 μmol/L had desensitization (n=6,P＜0.05) to SAPs and Fc.The desensitization of ACh on APD in AF was concentration- and time-dependent.It was shown that APD was longer than the control along with extending time of continuous Tyrode's solution perfusion after desensitization.It is concluded that ACh changes the electrophysiological characteristics of human AF,indicating that increased vagal tone plays a role in the development of a vulnerable substrate for atrial electrical remodeling in atrial fibrillation.
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Summary: The regulation of hypoxic response elements on the expression of vascular endothelial growth factor (VEGF) gene transfected to primary cultured rat skeletal myoblasts under hypoxic environment was investigated, pEGFP-C3-9HRE-CMV-VEGF vector was constructed with molecular biology technique and transfected to primary cultured rat skeletal myoblasts by lipofectamine in vitro. Gene expression of transfected myoblasts was detected by RT-PCR, Western blot and fluorescence microscope under different oxygen concentrations and different hypoxia time. The results showed that in hypoxia group, the VEGF gene bands were seen and with the decrease of oxygen concentrations and prolongation of hypoxia time, the expression of VEGF mRNA was obviously increased.Under hypoxic environment, the expression of VEGF protein in the transfected myoblasts was significantly increased. EGFP was expressed only under hypoxic environment but not under normoxic environment. It was concluded that hypoxia promoter could be constructed with HRE and regulate the expression of VEGF gene under hypoxic and normoxic environment, which could enhance the reliability of gene therapy.