Simvastatin Attenuates the Oxidative Stress,Endothelial Thrombogenicity and the Inducibility of Atrial Fibrillation in a Rat Model of Ischemic Heart Failure

Increased atrial oxidative stress has an important role in inducing and maintaining atrial fibrillation (AF), and the activation of the small GTPase Rac1 contributes to the oxidative stress. We investigated the relationship of Rac1, atrial endothelial thromboprotective markers and AF inducibility and if simvastatin has a potential beneficial effect on a myocardial infarction (MI)-induced heart failure (HF) rat model. Rats were randomized into three groups (shams, MI group and simvastatin treatment group) and underwent echocardiography, AF induction studies and left atrial (LA) fibrosis analysis. Atrial Rac 1, sodium calcium exchanger (I_NCX), sarcoplasmic reticulum calcium ATPase (SERCA), endothelial nitric oxide synthase (eNOS) and induced nitric oxide synthase (iNOS) were measured. AF inducibility, AF duration and LA fibrosis were significantly higher in the MI group (p < 0.001 vs. sham), which were significantly reduced by simvastatin (p < 0.05 vs. MI). The reduced expressions of atrial eNOS, SERCA, thrombomodulin, tissue factor pathway inhibitor and tissue plasminogen activator in the MI group were significantly improved by simvastatin. Furthermore, the increased expression of atrial iNOS, I_NCX and Rac1 activity were significantly decreased by the simvastatin. Oxidative stress, endothelial dysfunction and thrombogenicity are associated with the promotion of AF in a rat model of ischemic HF. These were associated with increased Rac1 activity, and simvastatin treatment prevents these changes.     

Lyocell纤维——减少原纤化的替代方法

除了用树脂整理来减少Ｌｙｏｃｅｌｌ纤维原纤化之外，还存在其他可能，本文对 可能性进行了研究。反应性染料由于结构和浓度因素而影响原纤维化性能，甚至连无色的反应性物质也能对此造成影响，这很容易由Ｌｙｏｃｅｌｌ纤维的湿态抗原纤维所证实。对抗皱与洗旧性也进行了评价。     

Use of modified sample entropy measurement to classify ventricular tachycardia and fibrillation

A study of ventricular fibrillation (VF) and ventricular tachycardia (VT) was undertaken using modified sample entropy analysis. Sample entropy (SampEn) is believed to provide the quantitative information about the complexity of experimental data that is corrupted by noise, short in data length. However, the similarity definition of vectors is based on a Heaviside function, of which the boundary is discontinuous and hard, which may cause the problems in the validity and accuracy of SampEn. To deal with the encountered problems, a modified sample entropy (mSampEn) based on fuzzy membership function was proposed. Its performances on characterizing VF and VT signals, as well as several simulated time series, demonstrate that mSampEn can more efficiently measure the complexity of time series. It is shown that, as a criteria for discriminating between VF and VT, mSampEn provides a significantly (p < 0.0001) higher (99%) accuracy rate than the standard one.     

不同强度华法林在冠状动脉粥样硬化性心脏病并发心房颤动患者中的效果对比

目的:探讨不同强度华法林在冠状动脉粥样硬化性心脏病并发心房颤动患者中的效果。方法: 选取2011年6月到2013年7月期间我院收治的冠状动脉粥样硬化性心脏病并发心房颤动患者107例,采取随机数字表的方式将患者随机分成对照组和试验组;试验组54例,对照组53例;试验组（低强度）初始量1.25 mg/d,服药后24 h开始监测国际标准化比值（INR）,若INR<1.4,3～5 mg/d增加0.5～1.0 mg/d,1周监测1次,INR维持1.4～2.0。对照组（中强度）INR维持2.0～2.6。INR稳定后监测1次/月。所有患者都经过约 4周的调整时间,华法林维持剂量1.25～7.5 mg/d;观察比较两组治疗2年后主要终点和次要终点及出血事件。结果: 试验组和对照组INR分别为1.71±0.38、2.36±0.35,试验组低于对照组,差异有统计学意义（P<0.05）;试验组和对照组的总出血事件比例为22.2%、41.5%,试验组低于对照组,差异有统计学意义（P<0.05）。结论:低强度的华法林治疗冠状动脉粥样硬化性心脏病并发心房颤动的治疗效果与中强度华法林治疗的效果相当,但低强度的华法林的安全性更高。     

胺碘酮及氯沙坦对慢性房颤射频消融术后心房结构及房颤复发的影响

目的: 探讨胺碘酮及氯沙坦对慢性房颤射频消融术(RFCA)后心房结构及房颤复发的影响。方法: 将本院2010年1月-2012年12月期间经RFCA的入选患者240例,按照随机化原则分为两组:胺碘酮组(A组,120例)和胺碘酮+氯沙坦组(B组,120例),A和B两组按照持续性房颤或永久性房颤再分别分为A₁、A₂和B₁、B₂两个亚组,比较术后6、12、18个月两组及其亚组左房前后径(LAD)、左房容积(LAV)及房颤复发率。结果: A、B组及其亚组术前LAD、LAV比较差异均无统计学意义(P>0.05),LAD和LAV术后有不同程度缩小,A组和A₁亚组均大于相对应时间的B组和B₁亚组且差异有统计学意义(P<0.05),A₂和B₂术后6个月差异有统计学意义(P<0.05),术后12、18个月的差异无统计学意义(P>0.05)。术后18个月,A组、A₁和A₂亚组窦性心律维持率 50.83%、53.85%和 48.53%,低于对应的B组、B₁和B₂亚组的 77.50%、80.00%和 75.71%,且差异有统计学意义(P<0.05),其中部分复发者再治疗后窦性心律维持率差异无统计学意义(P>0.05)。结论: 胺碘酮联合氯沙坦在首次RFCA术后较单用胺碘酮的疗效及左房重塑效应更好,复发率更低,这可能与氯沙坦的心房结构重塑和心电传导重建有关,但对术后复发患者的应用价值需进一步研究。     

In situ fibrillation of isotactic polypropylene in ethylene-vinyl acetate: Toward enhanced rheological and mechanical properties

In situ microfibrillar reinforced composites with ethylene-vinyl acetate (EVA) as matrix and isotactic polypropylene (iPP) as dispersed fibrils were successfully fabricated by multistage stretching extrusion with an assembly of laminating-multiplying elements (LMEs). Four types of EVA with different apparent viscosity were utilized to study the influence of viscosity ratio on the morphology and mechanical properties of EVA/iPP in situ microfibrillar blends. The scanning electron micrographs revealed that the dividing–multiplying processes in LMEs could effectively transform the morphology of iPP phase into microfibrils and the morphology of iPP microfibrils strongly depended on the viscosity ratio. Higher viscosity ratio was favorable for formation of finer microfibrils with narrower diameter distribution. The morphology development of iPP with different viscosity ratio greatly affected the rheological and mechanical properties of EVA/iPP blends. The dynamic rheological results shown that the iPP microfibrils were helpful to increase the storage modulus and loss modulus. The tensile test indicated that the mechanical properties of EVA/iPP blends were controlled by the morphology of iPP phase and the polarity of EVA matrix. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47557.     

Fibrous raw material of bamboo origin with improved fibrillation and spinnability

For making use of the natural biomass, the textile features of the bamboo fibres were optimized. Since lignin content of the fibres is responsible for its textile properties, the alkali-treated bamboo fibres were bleached with peracetic acid that resulted into the desired removal of lignin content of the fibres. As evident from the scanning electron microscopic images, the morphology of the fibres was much improved over the control samples. The resulting fibre possesses desirable tenacity, colouring properties and strength. Overall, an improved method for chemical treatment of bamboo fibres is developed so that this natural biomass is used for textile purpose.     

原纤化过程对纸基空气滤材结构和性能的影响

以木浆为原料,分别采用不同磨浆转数对木浆纤维进行原纤化处理,使其表面分丝帚化,再利用冷冻干燥技术保持纤维表面分丝状态而避免角质化,从而制备出可生物降解的纸基空气过滤材料。研究了不同程度原纤化处理对纸基空气滤材结构和性能的影响,探讨了原纤化处理对滤材Z向形貌的影响机理。结果表明,浆料浓度为1.5%、冷冻温度为-56℃、磨浆转数为50000 r时,纸基空气滤材具有较佳的过滤性能。     

房颤患者华法林初始剂量及出血危险因素的调查分析

目的: 比较两种华法林初始剂量在房颤患者中应用的安全性及有效性,并探讨其出血相关危险因素。方法: 采用回顾性调查方法,将某医院服用华法林的住院房颤患者按初始剂量分为超低剂量组(1.25~1.875 mg)和低剂量组(2.5~3.0 mg),比较两组患者抗凝的安全性和有效性指标。同时采用Logistic回归分析主要的出血危险因素。结果: 超低剂量患者各项安全性指标与低剂量组均无统计学差异(P>0.05);但前者首次达到目标国际标准化比值(INR)的时间较后者显著延长(P＜0.05),同时INR低于目标范围的比例显著增加且INR的控制率显著降低(P＜0.001)。年龄>65岁,肝功能不全,出血体质,卒中史,联用胺碘酮会显著增加华法林的出血风险(OR>1且P<0.05)。结论: 房颤患者应用超低初始剂量华法林抗凝的出血风险与低初始剂量相当但血栓风险增加;对于联用胺碘酮的患者,应加强出血风险的监护。