基于小波多分辨分析的第一第二心音提取

在心音信号的分析中,为了有针对性的分析第一心音(S1)、第二心音(S2)、第三心音(S3)、第四心音(S4),首先需要将它们从采集的心音信号中分离出来.本文提出一种方法,利用小波多分辨分析,提取第一心音及第二心音的同步信号,从而完成对第一心音和第二心音的实时分离.该方法区别于传统的依靠心电信号进行同步提取第一心音和第二心音的方法,避免了采集心音信号的同时需采集心电信号的麻烦,也提供了一种实现信号自同步的思路.用本方法对28例心音信号进行了仿真实验,1、S2均能被正确地分离出,表明该方法是可行的.     

肿瘤发生的潜在分子基础(1)

肿瘤发生是一个多步骤过程.绝大多数人肿瘤由产生了系列相继变化的单一细胞形成.这些变化导致细胞有丝分裂信号或生长控制的细微异常,逐步赋予细胞赘生的特性,直至细胞形成恶性肿瘤.防御肿瘤发生的一个重要机能是诱导细胞死亡,这种机能持续不断地清除机体内多余的,受损的或变异的细胞.对肿瘤细胞增殖优势的分子机理的认识,揭示了许多肿瘤细胞如何应答异常有丝分裂信号的内在现象,而蛋白磷酸激酶是介导这些信号通路的主体.天然细胞或病毒蛋白能作为细胞死亡效应子发挥作用,尤其有意义的是,有些细胞和病毒蛋白具有肿瘤特异性细胞死亡效应,可望发展成为新的抗肿瘤治疗制剂.     

益肾活血胶囊对高同型半胱氨酸血症及动脉粥样硬化兔TGF-β_1 mRNA和蛋白表达的影响

目的探讨益肾活血胶囊对高同型半胱氨酸（Hcy）血症致动脉粥样硬化（AS）兔转化生长因子-β1（TGF-β1）表达的影响。方法 48只新西兰兔,随机平分为正常组、模型组,益肾活血胶囊小剂量组、中剂量组、大剂量组及西药（叶酸、维生素B6、维生素B12）组,除正常组外,其他组建立高Hcy血症及AS动物模型,分别给予相应的药物治疗,观察血浆Hcy浓度、腹主动脉血管形态学变化及TGF-β1mRNA和蛋白表达。结果益肾活血胶囊和叶酸等维生素均可明显降低血浆Hcy水平,减轻血管内膜厚度,下调腹主动脉TGF-β1mRNA和蛋白表达,益肾活血胶囊大剂量组疗效最佳。结论益肾活血胶囊可明显降低血浆Hcy水平,抑制Hcy诱导的动脉粥样硬化形成,其机制可能与抑制TGF-β1表达有关。     

红花注射液热转化的HPLC/UV/MS特征图研究

目的 通过HPLC/UV/MS技术研究红花注射液(红花)的热转化特征图谱中特征峰的化学成分,并进行初步判定.方法 以红花药材超声水提取液和热提取的特征峰变化与红花注射液作比较.检测方法采用色谱柱Alltima C18(250mm ×4.6 mm,5μm);流动相0.2％醋酸水溶液-乙腈,梯度洗脱;检测波长310 nm,403 nm;体积流量0.8 mL/min;电喷雾质谱(ESI-MS)分析,正、负离子一级扫描,扫描范围(m/z)200～1 200.结果 标示出了红花热转化图谱中的4个特征峰,其中羟基红花黄色素A(10 min)及其同分异构体(21 min)的峰对热是稳定的,橙酮(42 min)的峰对热是不稳定的,查尔酮(33 min)的峰是受热后产生的.结论 该方法揭示了红花注射液和红花药材中热稳定物质、热不稳定物质的转化结果.     

甘草毛状根诱导培养及其黄酮含量检测的研究

 目的 探讨影响甘草毛状根的诱导培养的因素及其总黄酮含量。方法 利用发根农杆菌的遗传和液体培养技术,研究了甘草（Glycyrrhiza uralensis毛状根的诱导和离体培养及其黄酮的产生情况。结果 不同发根农杆菌中,A4菌株侵染效果最好,约96%的子叶节外植体产生毛状根;不同外植体中,子叶节的转化效果最高,毛状根产生只需3~4 d;在毛状根的液体培养过程中,接种量为0.3 g,培养容积为500 mL时生长速率最快,毛状根湿重增长41倍;毛状根能产生药用成分甘草黄酮,根系中最高黄酮含量高于商品甘草,达干重的2.042%,约为未转化植株根的4.3倍;毛状根中的黄酮还分泌到培养液中,最高量为每100 mL培养液1.36 mg。结论 较为系统地研究了甘草毛状根的诱导培养条件和总黄酮量,为今后规模培养甘草毛状根生产药用甘草黄酮提供了可能性。     

斑蝥在生物转化前后斑蝥素含量比较

目的:利用斑蝥与红栓菌进行生物发酵转化的新方法,探索提高中药斑蝥中可利用的斑蝥素含量,增加斑蝥素的溶出率,从而扩大斑蝥资源的更有效利用。方法:以斑蝥素为标准品,用气相色谱法测定斑蝥中生物转化前后斑蝥素含量。采用HP-5气相色谱柱,香兰素为内标,柱温为175℃保持5 min,4℃/min升到240℃,保持5min,建立了斑蝥素含量测定方法。结果:建立的测定方法具有良好的重现性,转化前斑蝥中可溶出斑蝥素的含量为0.70%,转化后可溶出斑蝥素的含量为1.29%,转化前后测得斑蝥素的含量有明显提高。结论:利用红栓菌发酵对斑蝥素含量的提高具有重要的意义,为斑蝥资源的有效利用提供实验依据。     

CHI3L1 (YKL‐40) is expressed in human gliomas and regulates the invasion,growth and survival of glioma cells

Chitinase 3‐like 1 (CHI3L1) is a secreted glycoprotein that has pleiotropic activity in aggressive cancers. In our study, we examined the expression and function of CHI3L1 in glioma cells. CHI3L1 was highly expressed in human glioma tissue, whereas its expression in normal brain tissue was very low. CHI3L1 suppression by shRNA reduced glioma cell invasion, anchorage‐independent growth and increased cell death triggered by several anticancer drugs, including cisplatin, etoposide and doxorubicin, whereas CHI3L1 overexpression had the opposite effect in glioma cells. Because the invasive nature of glioma cells plays a critical role in the high morbidity of glioma, we have further defined the role of CHI3L1 in the process of glioma invasion. Downregulation of CHI3L1 results in decreased cell–matrix adhesion and causes a marked increase in stress fiber formation and cell size with fewer cellular processes. Furthermore, the expression and activity of matrix metalloproteinase‐2 was also decreased in glioma cells in which CHI3L1 was knocked down. Taken together, these results suggest that CHI3L1 plays an important role in the regulation of malignant transformation and local invasiveness in gliomas. Thus, targeting the CHI3L1 molecule may be a potential therapeutic molecular target for gliomas.     

Evolved pseudo-wavelet function to optimally decompose sEMG for automated classification of localized muscle fatigue

The purpose of this study was to develop an algorithm for automated muscle fatigue detection in sports related scenarios. Surface electromyography (sEMG) of the biceps muscle was recorded from ten subjects performing semi-isometric (i.e., attempted isometric) contraction until fatigue. For training and testing purposes, the signals were labelled in two classes (Non-Fatigue and Fatigue), with the labelling being determined by a fuzzy classifier using elbow angle and its standard deviation as inputs. A genetic algorithm was used for evolving a pseudo-wavelet function for optimising the detection of muscle fatigue on any unseen sEMG signals. Tuning of the generalised evolved pseudo-wavelet function was based on the decomposition of twenty sEMG trials. After completing twenty independent pseudo-wavelet evolution runs, the best run was selected and then tested on ten previously unseen sEMG trials to measure the classification performance. Results show that an evolved pseudo-wavelet improved the classification of muscle fatigue between 7.31% and 13.15% when compared to other wavelet functions, giving an average correct classification of 88.41%.     

基于图像几何变换映射的色盲矫正方法

为了提高色盲患者分辨色彩的能力,提出了基于图像几何变换映射的色盲矫正方法。首先根据图像中颜色面两侧的颜色比例对颜色空间各个平面进行相应的几何变换,进而划分不同的颜色映射区域,通过颜色变换,生成色盲患者较易分辨颜色的图像。实验表明,该方法可以改善色盲患者对原本难以区分的颜色的分辨能力,同时计算速度快,有望满足实时处理的需要,性能上优于已有的方法。