一点红提取物抑菌活性研究

采用滤纸片法测定了一点红乙醇提取物对各种供试菌种的抑菌圈直径,同时就一点红提取物浓度以及加热处理对一点红提取物抑菌效果的影响进行了初步研究.结果表明:一点红乙醇提取物对G~-和G~-细菌有较强的抑制作用,而对霉菌抑菌效果不明显一点红提取物抑菌作用因菌种不同而最低抑菌质量浓度有所不同,大肠杆菌为0.05g·ml~(-1)、金黄色葡萄球菌为0.0625g·ml~(-1)、枯草芽孢杆菌为0.125g·ml~(-4),其抑菌圈直径分别为:大肠杆菌12.1mm、金黄色葡萄球菌15.3mm、枯草芽孢杆菌14.9mm,表明对常见细菌有较好的抑制作用,其在7h时抑菌效果最好.而对于真菌,黑根霉和米曲霉的最佳抑菌质量浓度分别为0.125g·ml~(-1)和0.05g·ml~(-1).在111℃湿热条件下20min后一点红提取物抑菌效果基本不变,说明一点红提取物具有良好的热稳定性.     

A-单调映象的广义隐拟变分包含

本文引入了一类A-单调映象的广义隐拟变分包含问题,利用A-单调映象的预解算子技巧研究了这类变分包含解的迭代算法逼近,证明了其解的存在性以及由算法生成的迭代序列的收敛性。     

拟共形映射的唯一极值问题

拟共形映射的极值问题是拟共形映射理论中的重要课题,将考虑曲面R=U Ri(i∈I)上的极值问题,其中每个Ri为双曲Riemman曲面,Ri ∩Ri=Φ,i≠j,I为可数非空指标集.我们将把经典情形极值问题的几个重要结果推广到我们要研究的空间R上来.     

社会网络与大学毕业生的就业研究

中国国内的劳动力市场可划分为体制内和体制外两块,格兰诺维特的弱关系假设可运用于毕业生的体制外求职,因为弱关系让求职者拥有不同特征的关系网络,利于求职者把握求职信息,而边燕杰的强关系假设可运用于毕业生的体制内求职,因为求职者利用强关系对于权力的拥有者施加影响,而获得职位。研究发现毕业生不论在体制内或体制外求职,都要求自身拥有一定的实力。     

超声波提取扁蓄总黄酮及测定

目的:从扁蓄中提取总黄酮并测定其含量.方法:选择乙醇为溶剂,用超声波技术从扁蓄中提取黄酮类物质,并对所提取的黄酮类物质进行验证,用分光光度法测定含量.结果:测得样品中总黄酮的平均含量为1.88%,平均回收率为100.95%.结论:运用超声波法从扁蓄中可以提取出黄酮类物质,加快提取速度,提高提取效率.     

CD40L对B淋巴细胞表面分子及分泌IL-12的影响

在体外使用CD40L作用于B淋巴细胞使之活化,通过测定B淋巴细胞表面分子及分泌细胞因子的变化,探讨B淋巴细胞作为抗原递呈细胞在抗肿瘤免疫中的优势,为B淋巴细胞特异性活化细胞毒T淋巴细胞(cytotoxic T lymphocyte,CTL)进而发挥其肿瘤细胞杀伤效应奠定基础.取7名健康成人外周静脉血,经淋巴细胞分离液分离人外周血单个核细胞(PBMC),分为对照组和实验组,实验组培养液中加入加入CD40L和IL-4,共培养21 d.观察B淋巴细胞生长状况,并在第7 d、第14 d和第21 d,用流式细胞仪(FCAS)测定其表面分子CD80、CD86和CD19,在第21 d,使用酶联免疫吸附法(ELISA)测定培养液中的IL-12水平.结果显示,在CD40L的作用下,B淋巴细胞呈克隆样增殖,并高表达表面分子CD80/CD86和CD19,和对照组相比,B淋巴细胞分泌IL-12水平升高(P＜0.05).上述实验结果说明通过CD40L的刺激,B淋巴细胞得到了活化,提示通过该途径活化的B淋巴细胞具备了作为抗原递呈细胞而发挥其抗肿瘤免疫治疗的能力.     

Water‐disintegrative and biodegradable blends containing poly(L‐lactic acid) and poly(butylene adipate‐co‐terephthalate)

In this study, novel biodegradable materials were successfully generated, which have excellent mechanical properties in air during usage and storage, but whose structure easily disintegrates when immersed in water. The materials were prepared by melt blending poly(L ‐lactic acid) (PLLA) and poly(butylene adipate‐co‐terephthalate) (PBAT) with a small amount of oligomeric poly(aspartic acid‐co‐lactide) (PAL) as a degradation accelerator. The degradation behavior of the blends was investigated by immersing the blend films in phosphate‐buffered saline (pH = 7.3) at 40 °C. It was shown that the PAL content and composition significantly affected morphology, mechanical properties, and hydrolysis rate of the blends. It was observed that the blends containing PAL with higher molar ratios of L ‐lactyl [LA]/[Asp] had smaller PBAT domain size, showing better mechanical properties when compared with those containing PAL with lower molar ratios of [LA]/[Asp]. The degradation rates of both PLLA and PBAT components in the ternary blends simultaneously became higher for the blends containing PAL with higher molar ratios of [LA]/[Asp]. It was confirmed that the PLLA component and its decomposed materials efficiently catalyze the hydrolytic degradation of the PBAT component, but by contrast that the PBAT component and its decomposed materials do not catalyze the hydrolytic degradation of the PLLA component in the blends. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2010     

Smooth solutions for a stochastic hydrodynamical equation in Heisenberg paramagnet

In this article, we consider a stochastic hydrodynamical equation in Heisenberg paramagnet driven by additive noise. We prove the existence and uniqueness of smooth solutions to this equation with difference method.     

Internal waves in a two‐layer system using fully nonlinear internal‐wave equations

In order to understand the nonlinear effect in a two‐layer system, fully nonlinear strongly dispersive internal‐wave equations, based on a variational principle, were proposed in this study. A simple iteration method was used to solve the internal‐wave equations in order to solve the equations stably. The applicability of the proposed numerical computation scheme was confirmed to agree with linear dispersion relation theoretically obtained from variational principle. The proposed computational scheme was also shown to reproduce internal waves including higher‐order nonlinear effect from the analysis of internal solitary waves in a two‐layer system. Furthermore, for the second‐order numerical analysis, the balance of nonlinearity and dispersion was found to be similar to the balance assumed in the KdV theory and the Boussinesq‐type equations. Copyright © 2009 John Wiley & Sons, Ltd.     

对称化L2-偏差下组合设计的均匀性

基于对称化L2-偏差讨论了组合设计的均匀性,在两种特殊的情形下分别得到了两水平部分因子设计的组合设计的离散偏差的下界,数值例子说明这些下界是紧的,因此这些下界可以作为寻找最优折叠反转方案的基准。