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.     

低温等离子体处理纤维素纤维的机理和性能研究

本文应用不同技术参数的低温等离子体对Lyocell纤维进行处理,借助SEM等手段对其表面特征和物理性能进行研究,通过化学热力学和化学动力学,对反应机理做了研究和分析,证明了通过这种新型手段对Lyocell纤维进行接枝和改性的可行性和优越性,并针对Lyocell纤维的一些相关性能进行了处理前和处理后的比较,结果表明低温等离子体处理后的Lyocell纤维在不降低物理机械性能的同时很大程度上减少了纤维的原纤化。     

芳纶Ⅲ纤维的原纤化研究

对芳Ⅲ纤维进行原纤化处理并对原纤化过程中纤维的形态结构变化进行了研究。SEM观察发现:芳Ⅲ纤维在原纤化过程中出现皮层剥落、结构疏松、轴向劈裂、进一步解离从而实现原纤化。对制备的芳Ⅲ原纤化浆粕进行表征,结果表明制得的浆粕打浆度达到60°SR,保水值为261%,比表面积9.42m2/g,结晶度42.49%。     

某型飞机超薄腹板类零件的加工

对某型机超薄腹板类零件的加工方案进行了研究,列举了传统的加工方案和多种新式加工方案,并对各种加工方案进行了对比,分析了各自优势和不足,凸显出新式加工方案在此类零件加工中的优势。     

天丝/锦纶交织桃皮绉染整工艺实践

利用锦纶纤维热收缩性能和天丝纤维原纤化特性,通过选择合理的热收缩和原纤化工艺条件,可以获得满意的桃皮绒绉纹效果;定型时要注意解决保持绉纹效果与手感和防水性之间的关系。面料手感柔软富有弹性,风格独特时尚。     

Tencel纤维与粘胶纤维的湿加工性能比较

通过打浆实验，研究探讨了Tencel纤维与粘胶纤维的湿加工性能，结果表明：Tencel纤维由于其良好的刚性、湿强度及易于原纤化的特征，使其具有良好的湿加工性能，从而为Tencel纤维在特种纸领域的开发应用提供理论依据。     

高原纤化Lyocell纤维的制备及其性能

为探究Lyocell纤维原纤化的生成条件,拓展高原纤化Lyocell纤维在过滤织物、覆盖面料及吸收衬垫等领域的应用,以次氯酸钠(NaClO)溶液为氧化剂,采用汽蒸处理方法制备了不同原纤化程度的Lyocell纤维,研究了NaClO 溶液质量分数和热处理时间对Lyocell纤维结构及性能的影响。结果表明:在本文实验范围内,当NaClO 溶液质量分数(有效Cl^-质量分数)为1.50%、热处理时间为180 s时,Lyocell纤维表面微原纤分布均匀、原纤化程度最为明显,纤维保持了较强的吸湿能力,较未处理前升高了135.8%,其干态断裂强度为3.69 cN/dtex,断裂伸长率为11.3%,基本保持了后续应用领域要求的较高力学性能。该方案实施难度小,效率高,有利于高原纤化Lyocell纤维在水刺织物、混纺制造纺织用品等领域的应用和工业化推广。     

心电图信号的频域分析

提出了一种简便有效的、由心电图（ECG）曲线提取QRS-T复合波的新方法，从而获得P波（当房颤未发生时）或f波（当房颤时）；利用功率谱、自相关、互相关等信号处理技术，对它进行了处理和分析，特别是，比较了未房颤时和发生房颤时的相关信息的显著差别。