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1.
通过三亲结合转移方式,将含人肿瘤坏死因子α(TNF_α)cDNA和psbA启动子的鱼腥藻-大肠杆菌穿梭质粒PDC_TNF导入单细胞丝状鱼腥藻7120中.Southern杂交结果表明,人肿瘤坏死因子αcDNA在鱼腥藻7120细胞中能以自主复制形式存在于PDC_TNF质粒上.SDS_PAGE和免疫印迹分析结果显示,转PDC_TNF的鱼腥藻7120可表达分子量约为17ku的人TNF_α,其表达量约占藻体蛋白的16%左右.转PDC_TNF的鱼腥藻7120粗提液的TNF生物学比活性约为25×104u/mg.  相似文献   

2.
用SDS-PAGE对经超声波处理的气味沙雷氏菌全菌体进行分离,切胶分别洗脱,经丙酮沉淀、脱盐处理后得到九个蛋白组分,将九个组分分别用L929,QGY肿瘤细胞为靶细胞进行细胞毒性试验(MTT),经初步鉴定从此且分具有抗癌细胞活性,组分F6相对分子质量范围为28000-33000,其抑制50%细胞生长的蛋白浓度(IC50);对L929细胞为0.046mg/ml对QGY细胞为0.01250mg/ml,活  相似文献   

3.
人肿瘤坏死因子穿梭表达载体的构建   总被引:10,自引:1,他引:9  
应用DNA重组技术,将人肿瘤坏死因子(rhTNF)cDNA插到质粒PRL439的PpsbA启动子下游,得到中间载体PRL_TNF;再把PRL_TNF上含PpsbA和(rhTNF)cDNA的片段连到穿梭载体PDC_8上,构建成穿梭表达载体PDC_TNF.转化大肠杆菌TG1后,进行发酵培养.SDS_PAGE分析和免疫印迹检测结果显示rhTNF获稳定表达,分子量为17ku.本研究结果为rhTNF在蓝藻中的表达提供了技术基础.  相似文献   

4.
目的 探讨TNF-α在SLE患者免疫调节紊乱中的作用。方法 ELISA法测定血清TNF-α蛋白水平,PBLRNA斑点杂交测定TNF-α蛋白水平有增高趋势,但血清TNE-α蛋白水平差别很大。TNF-α基因转录比正常显著增高(P〈0.01)。结论 提示TNF-α参与SLE的免疫调节紊乱。  相似文献   

5.
用正电子湮没技术(PAT),受体结合分析和L929细胞活力测定等方法研究了天然型hTNF-α和突变型hTNF-b肿瘤坏死因子(TNF)的结构特征。实验结果表明,在TNF-α中的正电子湮没长寿命(τ2)和相应强度(I2)分别大于和小于TNF-b的τ2和I2,用受体的放射配基结合分析,TNF-b对HEP-2(仅表达TNF-R55)和U937(主要表达TNF-R75)的ID50分别比TNF-α低1/2和高40倍。由此可得到一个有意义的结论,TNF-b的分子间自由体积减小,导致它的密度和细胞毒活性增大  相似文献   

6.
应用链霉菌抗生物素蛋白-过氧化物酶(SP)法染色技术测定65例非小细胞肺癌(NSCLC)组织标本的CD44v6、VEGF、C-erbB-2和nm23基因蛋白的表达水平。显示CD44v6、VEGF、C-erbB-2及nm23在NSCLC组织中表达的阳性率分别为66.2%、78.5%、63.1%及73.8%,均显著高于癌旁组织;上述四项指标阳性率与NSCLC的病理类型无明显关系;区域性淋巴结转移组CD  相似文献   

7.
用正电子湮没技术,受体结合分析和L929细胞活力测定等方法研究了天然型hTNF-α和突变型hTNF-b肿瘤坏死因子的结构特征。实验结果表明,在TNF-α中珠正电子湮没长寿命和相应强度分别大于和小于TNF-b的τ2和I2,用受体的放射配基结合分析,TNF-b对HEP-2和U987的ID50分别比TNF-α低1/2和高40倍。  相似文献   

8.
通过检测小鼠脾脏PFC,CD+4/CD+8T淋巴细胞亚群比值、淋巴细胞转化活性及脾细胞产生肿瘤坏死因子(TNF)等免疫指标,观察三普虫草精(SPCS)对环磷酰胺(CY)损伤小鼠免疫功能的影响。发现SPCS在有效剂量范围内单独使用,能促进CY损伤小鼠PFC功能的恢复(P<0.01);使因CY损伤而失调的CD+4/CD+8T淋巴细胞亚群比值得到改善(P<0.05);使降低了的淋巴细胞转化活性得以恢复(P<0.001);能显著促进ConA诱导CY损伤小鼠脾细胞TNFβ的合成与释放(P<0.001)。  相似文献   

9.
将人肿瘤坏死因子受体Ⅰ(hTNFRI)死亡域基因克隆在氯霉素乙酰转移酶(CAT)的后面,构建成重组表达质粒pLT10 CATLDd.该融合蛋白基因转化大肠杆菌后发酵,IPTG诱导2 h,SDS-PAGE测定CATLDd 蛋白质的分子质量为39 ku.Western 印迹实验进一步作了鉴定.表达产物为包涵体.CATLDd 蛋白质经Q-Sepharose 柱层析后纯度大于95% .  相似文献   

10.
用PCR突变的方法使人白血病抑制因子基因的终止密码子缺失,并与质粒pPICZαA上的myc表位及6个组氨酸处于同一读码框,构建融合表达载体pPICZαA-hLIFM.通过氯化理化学转化法使表达载体整合到毕赤巴斯德酵母X-33的基因组DNA中。转化子经甘油增菌和甲醇诱导,实现了hLIF基因在毕赤酵母表达载体系统中的表达.SDS-PAGE检测和 Western blot分析结果表明在相对分子质量为61 000处有一条人白血病抑制因子特异蛋白带.凝胶薄层扫描分析结果显示表达的目的蛋白占培养液上清总蛋白的 33.3%.且该表达产物具有抑制小鼠畸胎瘤细胞F9克隆形成的活性.  相似文献   

11.
There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.  相似文献   

12.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

13.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

14.
Instead of following Fock’s expansion,we solve the Schrodinger equation for some quantum mechanical manybody systems such as electrons in atoms and charged excitons in quantum wells in a similar way in hyperspherical coordinates by expanding the wave functions into orthonormal complete basis sets of the hyperspherical hannonics(HHs)of hyperangles and generalized Laguerre polynomials(GLPs)of the hyperradius.This leads the equation to  相似文献   

15.
Future mobile communication systems aim at providing very high data transmission rates, even in high-mobility scenarios such as high-speed wheel-track trains, maglev trains, highway vehicles, airplanes, guided missiles or spacecraft. A particularly important commercial application is the strong and increasing worldwide demand for high- speed broadband wireless communications (up to 574.8 km/ h test speeds or 380 km/h commercial speeds) in railways, providing data, voice and video services for applications such as onboard entertainment services to passengers, train control, train dispatch, train sensor status handling and sur- veillance. In such high-mobility scenarios, there are a number of communication challenges, including fast hand- over, location updating, high-speed channel modeling, estimation and equalization, anti-Doppler spreading tech- niques, fast power control, and dedicated network architec- ture. Because signal transmission in very high-speed scenarios will inevitably experience serious deterioration, it is imperative to develop key broadband mobile communi- cation techniques for such high-speed vehicles.  相似文献   

16.
17.
Being the primary media of geographical information and the elementary objects manipulated, almost all of maps adopt the layer-based model to represent geographic information in the existent GIS. However, it is difficult to extend the map represented in layer-based model. Furthermore, in Web-Based GIS, It is slow to transmit the spatial data for map viewing. In this paper, for solving the questions above, we have proposed a new method for representing the spatial data. That is scale-based model. In this model we represent maps in three levels: scale-view, block, and spatial object, and organize the maps in a set of map layers, named Scale-View, which associates some given scales.Lastly, a prototype Web-Based GIS using the proposed spatial data representation is described briefly.  相似文献   

18.
本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。  相似文献   

19.
Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with  相似文献   

20.
The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to  相似文献   

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