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1.
《科学通报(英文版)》2008,(19)
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. 相似文献
2.
薄亚明 《南京邮电大学学报(自然科学版)》2008,28(5)
通过模仿团队进步需要的学习、探索行为和成员更新规则,提出了一种新颖的双群体演化算法,称为团队进步算法(TPA).算法将一个团队的成员分为精英和普通组,建立了两组的学习样板,定义了学习和探索运算,并合理设定了成员更新规则.两组成员在搜索过程中出现了明显分工,使算法兼备了全局搜索、局部搜索和定向搜索的能力.数值试验结果验证了新算法具有实现简单、全局寻优成功率高、收敛快、计算量少、坚韧性强和参数选择相对容易等特性,对解决优化应用问题具有较大的价值. 相似文献
3.
徐惠萍 《科技情报开发与经济》2007,17(36):18-20
分析了大学生产生心理疾病的原因,探讨了"阅读治疗"对大学生心理健康的作用,提出了高校图书馆开展阅读治疗的措施。 相似文献
4.
本文论述了描述微波与生物组织相互作用的数学表达式,讨论工作频率选择、透入深度、反射、极化、泄漏及防护等实际问题。 相似文献
5.
研究螫合萃取剂1—苯基—3—甲基—4—苯甲酰吡唑酮—5(HPMBP)与酰胺型革取剂N_(503)氯仿溶液从硝酸介质中协萃钯(Ⅱ)的热力学行为。在30℃、pH=1.70条件下,萃取剂浓度与分配比的关系式可表达为lgD′=2.948lg[HPMBP]_((o)) 6.645,lgD″=0.9809lg[N_(503).HNO_3]_((0)) 2.796。温度与分配比的关系表达为lgD=424.923/T-0.3088。测得协革平衡常数k=34.67,焓变△H=-8.316kJ.mol~(-1),自由能变△G=-8.932kJ.mol~(-1)和熵变△S=2.036J.mol~(-1).K~(-1). 相似文献
6.
目的:探讨降纤酶对脑梗塞的治疗效果及对血液流变学的影响。方法:治疗组64例采用降纤酶治疗脑梗塞,对照组58例采用5%低分子右旋糖酐加维脑路通注射液静脉滴注治疗脑梗塞,进行对比观察。结果:对治疗前后患的神经功能缺损进行评定,治疗组降低纤维蛋白原、改善血液流变学明显优于对照组。结论:降纤酶溶栓治疗急性脑梗塞有一定疗效。 相似文献
7.
研究了HPMBP与N503的氯仿溶液从硝酸介质中协萃钯(Ⅱ)的性能.用斜率法和等摩尔系列法确定萃合物组成为(CH3CONHR2)Pd(PMBP)3;求得该协萃反应的平衡常数及协萃配合物的生成常数分别为:lgk12=1.54,lgβ12=2.39.考察了温度对协萃平衡的影响,测定了协萃反应的热力学函数. 相似文献
8.
Earthshaker: A mobile rescue robot for emergencies and disasters through teleoperation and autonomous navigation
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Yu Zhang Yuxiang Li Hefei Zhang Yu Wang Zhihao Wang Yinong Ye Yongming Yue Ning Guo Wei Gao Haoyao Chen Shiwu Zhang 《中国科学技术大学学报》2023,53(1):4-1-4-13
To deal with emergencies and disasters without rescue workers being exposed to dangerous environments, this paper presents a mobile rescue robot, Earthshaker. As a combination of a tracked chassis and a six-degree-of-freedom robotic arm, as well as miscellaneous sensors and controllers, Earthshaker is capable of traversing diverse terrains and fulfilling dexterous manipulation. Specifically, Earthshaker has a unique swing arm—dozer blade structure that can help clear up cumbersome obstacles and stabilize the robot on stairs, a multimodal teleoperation system that can adapt to different transmission conditions, a depth camera-aided robotic arm and gripper that can realize semiautonomous manipulation and a LiDAR aided base that can achieve autonomous navigation in unknown areas. It was these special systems that supported Earthshaker to win the first Advanced Technology & Engineering Challenge (A-TEC) championships, standing out of 40 robots from the world and showing the efficacy of system integration and the advanced control philosophy behind it. 相似文献
9.
《科学通报(英文版)》1998,43(5):363-363
During the long period of time when people have been seeking for an effective therapeutic method for PD, the gene therapy has shown greater and greater advantages over other methods. It can be performed mainly in two ways: ex vivo and in vivo. With the former, TH gene as well as some neurotrophic factor genes (such as GDNF, BNDF genes) can be invited to some cell lines or primary cells thus forming engineered cells and then implanting them into brain. While with the latter, viral vectors including HSV-1, Ad, AAV that can be utilized to construct recombinant viruses, or non-virus vectors can be used to delived DNA into brain directly. The present review summarizes the recent research advances in the gene therapy for PD, and it is reasonable for us to predict a notable progress in prevention and treatment for PD in the next decade. 相似文献
10.
脱臭蒜素胶囊的研制 总被引:2,自引:0,他引:2
孙东 《科技情报开发与经济》2005,15(19):182-183
介绍了大蒜的主要化学成分及食疗价值,探讨了大蒜的脱臭机理,阐述了脱臭蒜素胶囊的制造技术. 相似文献