公理化局部有限空间中映射连续性的扩展

用公理化方法研究了局部有限空间中的连续映射及其扩张问题。给出了局部有限空间的公理化定义方法;利用邻近关系研究了局部有限空间中的连续映射、同胚和局部同胚等问题;通过对局部有限空间变形的研究,定义了局部有限空间的一种特殊收缩核,有效地解决了局部有限空间中连续映射的扩张问题。     

大鼠血管内皮细胞siRNA转染条件的优化

目的:旨在优化siRNA转染大鼠血管内皮细胞的转染条件.方法:将0.75μL和1.5μL的脂质体LipofectamineTM3000分别与20、40、60、80nmol带荧光标记的FAMsiRNA组合,转染6、12、18、24h后,用荧光显微镜计数阳性细胞率、MTT法检测各浓度条件下内皮细胞的存活率,筛选最优转染条件.结果:(1)转染12h后,用荧光显微镜检测20、40、60、80nmol各组,均可观察到绿色荧光(2)siRNA浓度为60nmol/L,脂质体为1.5μL的组合转染效率最高,继续增加siRNA的浓度,转染效率提高不明显.(3)转染时间超过24h,各组细胞荧光减弱,细胞死亡率显著增加.结论:结果表明,以1.5μL LipofectamineTM3000与60nmol/L的siRNA浓度组成转染混合物转染12h可以实现对大鼠血管内皮细胞高效转染并保持较高的细胞活性.     

带有临界增长的Kirchhoff方程极小能量变号解的存在性

为了深入研究Kirchhoff方程的性质,讨论了带有Hartree项和临界增长非线性项的Kirchhoff方程极小能量变号解的存在性。利用能量泛函在变号Nehari流形上的下确界C_λ收敛于0,得到空间E紧嵌入L~6(R~3)这一技术性结果。结果表明,利用限制变分方法和定量形变引理获得极小化序列对应的极小值点是该问题的非平凡解。研究方法在理论证明方面得到了良好的结果,对研究其他Kirchhoff方程解的存在性有一定的指导意义。     

哺乳动物核移植研究进展

核移植技术具有重大的生物学的意义，特别是体细胞核移植技术的成功表明动物分化的体细胞核可再程序化，哺乳动物核移植的研究虽然还存在许多问题需要解决，但在挽救濒危动物，转基因动物研究，人类器官移植等许多方面展现了广阔的应用前景．     

PEMFC电催化剂利用率研究方法的探讨

提高电催化剂的利用率以降低质子交换膜燃料电池(PEMFC)的成本，是加速其商业化的一个重要途径。文中讨论了现有的CV法在研究PEMFC电催化剂利用率时存在的一些问题，如CV法扫描速度的影响及Pt理论比表面积难于准确确定等，为了较好地解决这一问题，提出了一种以单位质量电催化剂产生电池功率或电能来表示膜电极中电催化剂利用率的方法。     

光电转换体系太阳能聚集器

In standard P-V systems, the high cost and low quantum efficiency of silicon cells has held back widespread adoption of this technology for decades. To generate electrical power from solar energy in a cost effective way, most methods require the concentration of the sunlight in order to increase the efficiency of energy conversion. Most systems use parabolic mirrors to focus sunlight to either a line （trough systems） or a small volume （dishes）. One of the reasons solar power still remains little utilised, is the high cost of the collection systems. Light focussing devices using reflection usually take the form of a curved rein＇or. In contrast, this paper describes the new design of a device consisting of an array of small angled reflecting m/trot facets located in a planar form. The three dimensional angle of each facet in the array is a function of its position in the array, and is calculated to be such that for a parallel beam striking the array, each facet will reflect the light in such a way as to form a focal point region.     

Specific anti-tumor effect induced by attenuated Salmonella typhimurium vaccine expressing extracellular region of vascular endothelial growth factor receptor 2

The purposes of this research were to study the stable expression of exogenous gene encoding therapeutic protein in attenuated Salmonella typhimurium, observe the metabolism of oral gene vaccine carried by attenuated Salmonella typhimurium in BALB/c mouse, and investigate the feasibility of prevention and treatment of tumors by the recombinant bacteria. Recombinant plasmid pcDNA3.1 VEGFR2(n1-7) was transformed into competent attenuated Salmonella typhimurium SL3261 to develop oral DNA vaccine SL3261-pcDNA3.1 VEGFR2(n1-7). To observe whether the exogenous gene can be expressed in the recombinant bacteria, PCR was performed to amplify the CMV promoter of the eukaryotic expression vector as the proof of stable expression of exogenous protein; transmission elec- tron microscopy (TEM) was applied to observe the morphology of the recombinant bacteria to confirm that the exogenous gene has no impact on the growth of the bacteria, and then BALB/c mice were immunized with the gene vaccine. After inoculation of the gene vaccine, the recombinant bacteria SL3261 could be detected in the tissues such as small intestine, colon, liver and spleen. And then, mice in each group were challenged with tumor cells. The results of animal experiment showed that tumor growth of the mice in experimental group was inhibited and survival time of immunized mice was prolonged compared with control groups. A higher lymphocyte infiltration in tumors from animals treated with DNA vaccine was observed. Immunohistochemical analysis of tumor samples revealed an en- hanced accumulation of CD8 cytotoxic T lymphocytes, as well as an increase in CD4 cells in the tumors of animals treated with the oral gene vaccine compared to tumors from control group mice. Ultrastructure of the tumor tissue showed that tumor cells in the samples of the immunized mice were well-differentiated. Our research confirmed that the exogenous gene can be stably expressed in the attenuated Salmonella typhimurium and has no impact on the growth of the recombinant bacteria; the exogenous gene can de delivered to the host by attenuated Salmonella typhimurium to produce anti-tumor effect with no obvious cytotoxity to the host. In this study, it is established that attenuated Salmonella typhimurium could be used as a vector for oral gene vaccine, and our study provided a theoretical basis for the body distribution and the metabolism of the recombinant bacteria. This strategy may provide a simple, safe and effective way for the prevention and treatment of tumors.     

基于系统动力学理论建模的教育投资、经济增长和就业问题的研究

运用系统动力学的理论、方法构建模型,对教育投资、经济增长与就业问题进行了模拟,提出应加大教育投资力度,提高国民教育水平,将巨大的人口压力转化为巨大的人力资本优势,同时也必须兼顾由于人口总量以及其他因素导致的巨大的就业压力问题,在教育投资与固定投资之间保持合理的比例关系,以促进经济的持续、适度发展,为政府决策提供参考和依据。     

Therapeutic applications of bone marrow-derived stem cells in liver transplantation for end-stage liver diseases

Today, liver transplantation (LT) is the only established treatment for end-stage liver diseases. The de- velopment of LT, including OLT, cadaveric LT, split LT, living donor LT (LDLT), brings hopes to patients with these diseases. However, increasing donor shortage, rejection and life-long immunosuppression with its side effects are the major limitations of this therapy strategy. Bone marrow-derived stem cells (BMDSCs) are capable of differentiating into hepatocyte-like cells and contribute to liver injury repair. The microenvironment of liver injury caused by rejection, ischemia/reperfusion, loss of liver mass, recurrence of HCV and "small-for-size syndrome" after LT can attract a variety of bone marrow-derived stem cell population to the peripheral circulation and then migration to the injury liver to promote the hepatic function restoration. Additionally, BMDSCs can also take part in the functional regeneration of living donor liver after LDLT. This participation in liver regeneration may be associated to the interac- tion between SDF-1and its receptor CXCR4, involving HGF, IL-8, MMP9, and VEGF/VEGFR-2. BMDSC with its bio-characteristics could maintain the allograft tolerance from different angles and in different ways. In conclusion, BMDSCs transplantation, as a new assistant therapeutic method for LT, will ex- pand the space of LT, and provide more survival opportunities for the patients suffering liver diseases in the future.