青海湖旅游区生命周期问题探讨

本文立足青海实际，在分析影响青海湖旅游区生命周期的诸因素基础上，提出了延长该区旅游生命周期的具体措施。     

宇宙临界减速因子

本文证明了如果中微子具有质量,那么膨胀宇宙的临界减速因子q_c就不是通常所说的1/2而是等于1。     

传染病医院污水处理工艺选择案例

文章通过对临汾市传染病医院拟建的传染病区污水的来源、排放量、污染物的分析,结合污水处理原则,提出了具体的污水处理工艺。并根据污染物去除率预测了污染物浓度,与污染物排放标准进行对比分析,结果表明所选工艺处理后的污染物浓度能够达标,污水处理工艺是可行的。     

40Cr大轴断裂分析

对冶金矿山某产品的40Cr材料制作的大轴热处理后发生断裂现象，进行了理化检验及综合分析，找出了造成大轴断裂原因－首先是由于存在淬火应力，而未得到及时回火，其次是原材料中存在严重的冶金缺陷。     

植物基因环境效应启动子

植物的生长发育受到光照、温度、水分及氧等环境因素的影响，根据对不同环境的响应，植物基因的启动子主要可以分为光效应启动子，温度效应启动子和水效应启动子。在这些启动子中，除了含有基本启动子外，还存在一些特异的顺式调节元件，这些顺式调节元件在特异表达中发挥重要作用。     

卡介苗素治疗慢性支气管炎的临床观察

目的　研究卡介苗素对慢性支气管炎的预防及治疗作用 .方法　对 90例慢性支气管炎患者给予控制感染、对症治疗 .除常规给予止咳、化痰药外 ,同时肌注卡介苗素 2mL/次 ,每周 3次 ,3个月为 1个疗程 ,并与常规治疗对比 .结果　经治疗后卡介苗素组血清IgG(免疫球蛋白G)和IgE(免疫球蛋白E)明显下降 ,其抗复发的显效率、有效率分别为 4 7.8%、34.4 % ,总有效率为 82 .2 % ,显著优于对照治疗组 .结论　卡介苗素能明显改善机体免疫功能 ,对IgE有一定的调节作用 .     

中水回用前景及其实际意义

概述了中水及中水回用的概念,分析了目前中水回用中存在的问题,探讨了水源热泵技术的应用。     

靖西县新圩铝土矿地质特征及控矿因素

根据多年的实际工柞经验，论述了靖西新圩铝土矿床的地质特征及控矿因素。     

辽宁大学生身体健康状况的调查研究

运用问卷调查、健康检测及数理统计等方法,对辽宁大学生健康状况及影响诱因进行调查分析。结果表明:大学生身体健康状况基本良好,运动目的性呈现多元倾向。部分学生的认识和行为表现不一致,健康知识的知晓度欠缺,导致身体健康水平不高。提出相应改善对策,为高校实施健康教育、科教兴省提供参考。     

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.