Serotype-independent pneumococcal vaccines

Streptococcus pneumoniae remains an important cause of disease with high mortality and morbidity, especially in children and in the elderly. The widespread use of the polysaccharide conjugate vaccines in some countries has led to a significant decrease in invasive disease caused by vaccine serotypes, but an increase in disease caused by non-vaccine serotypes has impacted on the overall efficacy of these vaccines on pneumococcal disease. The obvious solution to overcome such shortcomings would be the development of new formulations that provide serotype-independent immunity. This review focuses on the most promising approaches, including protein antigens, whole cell pneumococcal vaccines, and recombinant bacteria expressing pneumococcal antigens. The protective capacity of these vaccine candidates against the different stages of pneumococcal infection, including colonization, mucosal disease, and invasive disease in animal models is reviewed. Some of the human trials that have already been performed or that are currently ongoing are presented. Finally, the feasibility and the possible shortcomings of these candidates in relation to an ideal vaccine against pneumococcal infections are discussed.     

Cell-permeable dual inhibitors of protein kinases CK2 and PIM-1: structural features and pharmacological potential

It has been proposed that dual inhibitors of protein kinases CK2 and PIM-1 are tools particularly valuable to induce apoptosis of cancer cells, a property, however, implying cell permeability, which is lacking in the case of selective CK2/PIM-1 inhibitors developed so far. To fill this gap, we have derivatized the scaffold of the promiscuous CK2 inhibitor TBI with a deoxyribose moiety, generating TDB, a selective, cell-permeable inhibitor of CK2 and PIM-1. Here, we shed light on the structural features underlying the potency and narrow selectivity of TDB by exploiting a number of TDB analogs and by solving the 3D structure of the TDB/CK2 complex at 1.25?Å resolution, one of the highest reported so far for this kinase. We also show that the cytotoxic efficacy of TDB is almost entirely due to apoptosis, is accompanied by parallel inhibition of cellular CK2 and PIM-1, and is superior to both those observed combining individual inhibitors of CK2 and PIM-1 and by treating cells with the CK2 inhibitor CX4945. These data, in conjunction with the observations that cancer cells are more susceptible than non-cancer cells to TDB and that such a sensitivity is maintained in a multi-drug resistance background, highlight the pharmacological potential of this compound.     

BP网络应用于黄河水质的预测研究

利用黄河兰州段水质指标浓度时间序列作为学习样本,选取了DO、COD、氨氮、重金属离子等l0项指标作为输出参数,运用人工神经网络BP模型中的Levenberg—Marguardt优化算法对学习样本优化建模,将优化好的网络的预测结果与实测结果进行了比较,表明BP网络可以很好地用于黄河水质指标值及水质类别的预测。     

地铁钢弹簧浮置板轨道垂向振动特性研究

摘要:针对我国部分地铁线路出现振动噪声加剧及钢轨异常波磨的现实情况,开展地铁钢轨波磨形成原因的研究.利用多体动力学仿真软件SIMPACK建立包含地铁车辆和轨道结构的车辆系统动力学模型,研究车辆-轨道系统动力学响应以及弹性轨道系统振动特性对波磨形成的影响.研究结果表明：改变轨道板长度、厚度、钢弹簧垂向刚度和跨度等轨道参数,浮置板的各阶固有频率均有所变化,但其振型特性基本不变;内侧钢轨在116和161Hz处易发生较为明显的共振现象,这可能造成波长为132和95mm内侧钢轨波磨现象的产生.综合钢轨和轨道板垂向弯曲振型以及频谱特性可知,轨道系统的垂向振动可能是造成钢轨波磨初期产生或促进其发展的主要原因,这些为此后研究钢弹簧浮置板轨道的钢轨波磨问题提供相应思路和方法.     

一种改进的规划器算法在军用软件GUI测试用例自动生成中的应用

以人工智能中智能规划方法为基础,对军用软件测试用例自动生成技术进行了研究。现有的许多规划器都不能避免组合爆炸问题的发生,而这一问题又是导致规划失败的一个重要问题,针对这一现象,以IPP规划器为例,提出目标分解法对规划器所需事实文件进行划分,并对IPP规划器应用多事实文件处理算法进行扩展,扩展后的MF-IPP规划器能够处理多个事实文档,有效避免了组合爆炸问题的发生。将该方法应用到军用主控软件GUI(Graphical User Interface)测试用例自动生成中,主要思想是首先利用规划器生成初始测试用例,其次提出解扩展的方法来完善测试用例的生成。针对测试用例生成问题进行了比对分析,结果显示,MF-IPP可以很好地防止组合爆炸问题的发生。所生成的测试用例生成时间短、覆盖率高,不仅能够很好地辅助软件测试人员进行测试用例的编写,还能应用于自动化软件测试。     

基于改进的卷积神经网络的钢号识别

为获取样本的多样性特征;提出了一种改进的卷积神经网络结构。该网络中引入多层递归神经网络;利用卷积神经网络提取输入图像的浅层特征;同时利用卷积神经网络和递归神经网络并行提取高层特征;最后将两种网络学习到的特征进行融合输入到分类器中分类。利用迁移学习理论解决小样本集数据训练不足的问题;并将这种卷积神经网络结构应用于石油物资管线钢号识别中。实验探究了递归神经网络个数与卷积核个数对网络性能的影响;实验结果表明;改进的网络结构与其它网络进行对比;错误率降低了 3% 。     

油田管道风险及完整性评价体系构建与应用

为提升油田管道安全隐患的预警和分析能力,根据 GB32167-2015《油气输送管道完整性管理规范》的要求和管道密集型油田的实际特点,对Ⅲ类管道进一步精细划分; 同时结合地理和周边居住区情况,对管道的高后果区进行有效识别,从而对管道进行风险等级分类,完善管道完整性的评价体系。通过互联网 + 数据驱动的模式建立油田管道完整性数据管理平台,以可视化方式全面评价油田管道运行风险。该平台可提高油田管道风险评估的准确性,确保及时准确预测风险。     

无人机航迹规划常用算法综述

为促进航迹规划技术的发展,对航迹规划常用算法进行综述。首先对航迹规划的规划思想和构成进行分析; 其次将航迹规划算法分为传统经典算法和现代智能算法两大类,对其中几种常用算法进行分析总结; 最后阐述现代智能算法在航迹规划应用中的改进、多重算法的融合改进以及多无人机四维航迹规划算法研究3 个研究热点及未来发展趋势。     

贮藏时间对单丛茶成分及其抑制脂肪酶、α - 葡萄糖苷酶活性的影响

以同一品种、不同贮藏时间的单丛茶样为试样,在分析对比其内含成分的基础上,对其体外抑制脂肪酶和α-葡萄糖苷酶的生物活性进行研究。结果表明：陈年单丛茶的茶多酚、儿茶素和游离氨基酸含量均低于新鲜茶样,水浸出物、可溶性总糖、没食子酸和茶黄素含量均高于新鲜茶样。儿茶素含量与茶黄素含量之间呈现极显著负相关。1996年单丛茶对脂肪酶活性的抑制率最高,为43.01%,2016年单丛茶对α-葡萄糖苷酶活性的抑制率最高,为94.48%。经相关性分析,推测没食子酸为单从茶抑制脂肪酶活性、发挥减肥作用的主要有效成分,咖啡碱可能是单从茶发挥降血糖作用的主要生物活性成分。本研究结果为单丛茶的深度开发和收藏增值利用提供了理论依据。     

Gemini表面活性剂在气/液界面上的微区形貌随表面压的变化

测定了Gemini表面活性剂在pH值为10．86,NaBr浓度为1．0mol／L的溶液气／液界面上的表面压一分子面积的等温线。用自制的Brewster角显微镜(BAM)观察了由Gemini表面活性剂在界面上所形成单分子膜的微区形貌随表面压的变化。结果表明：当pH值为10．86时,Gemini表面活性剂在1．0mol／L NaBr溶液的气／液界面上生成了凝聚态的单分子膜;当表面压较低时,观察到在界面上形成了同心圆结构;随着表面压的增加,这些同心圆可发生聚并而形成多中心结构。