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1.
氯酚红与人血清白蛋白的结合   总被引:3,自引:1,他引:2  
在人体条件下,用荧光光谱法研究了氯酚红(CPR)与人血清白蛋白(HSA)之间的相互作用.实验表明:氯酚红对人血清白蛋白的荧光有较强的猝灭作用,从荧光猝灭结果求得不同温度下CPR与HSA的结合常数K,随反应温度上升K值下降.由CPR与HSA反应焓变、熵变,确定CPR与HSA的结合主要是静电引力.依据非辐射能量转移机理,探讨了不同温度下CPR与HSA相互结合时,其给体-受体间距离和能量转移效率.进一步证实该反应为单一静态猝灭过程,且阐明了其猝灭机理是通过能量转移产生的.  相似文献   

2.
溴甲酚紫与血清白蛋白的相互结合反应   总被引:3,自引:3,他引:0  
应用荧光光谱法研究了水溶液体系中,溴甲酚紫与牛血清白蛋白(BSA)、人血清白蛋白(HSA)之间的相互作用.结果表明溴甲酚紫对血清白蛋白的荧光有较强的猝灭作用,其荧光猝灭主要为静态猝灭,从荧光猝灭结果求得不同温度下溴甲酚紫与BSA,HSA的结合常数K,发现随反应温度上升K值下降.由反应焓变、熵变,确定了溴甲酚紫与血清白蛋白的结合主要是静电引力.依据非辐射能量转移机理,测定了不同温度下溴甲酚紫与血清白蛋白相互结合时,其给体-受体间距离和能量转移效率.进一步证实了该反应为单一静态猝灭过程,且阐明了其猝灭机理是通过能量转移产生的.  相似文献   

3.
本文采用荧光猝灭光谱和紫外-可见吸收光谱研究木糖醇与人血清白蛋白(HSA)的相互作用。结果表明木糖醇对HSA有较强的荧光猝灭作用,荧光猝灭机理属于二者形成复合物所引起的静态猝灭和非辐射能量转移;根据不同温度下木糖醇对HSA的荧光猝灭作用,利用Stern-Volmer方程处理实验数据,得到木糖醇与HSA之间的结合常数KA为2.46×104 mol-1·L(298K)和1.01×104 mol-1·L(308K),结合位点数n分别为0.922 8和0.997 0。根据不同作用温度时非共价结合复合物的热力学参数变化,证明木糖醇与人血清白蛋白分子间的结合力主要是静电引力。研究结果为进一步研究木糖醇的药理和保健作用,尤其是对血浆蛋白构象的影响和新药品的开发提供了重要信息。  相似文献   

4.
应用荧光光谱法,研究了苦杏仁苷与人血清白蛋白(HSA)在pH=7.40的Tris-HCl缓冲溶液中相互作用的情况.研究表明,苦杏仁苷通过静态机理猝灭了HSA的内源荧光.并计算得到苦杏仁苷与HSA的结合常数和结合位点数.通过热力学数据,推断出苦杏仁苷与人血清白蛋白之间主要靠氢键和范德华力结合.同时采用同步荧光技术考察了苦杏仁苷对HSA构象的影响.  相似文献   

5.
采用荧光光谱法研究了Cu2+对1-酮-2-(对二甲氨基苯亚甲基)-四氢萘(KDTN)与人血清白蛋白(HSA)相互作用的影响.结果表明,Cu2+的存在对KDTN与HSA的猝灭类型及分子之间作用力没有影响,使KDTN对HSA的猝灭效应增强;荧光猝灭双倒数曲线表明,Cu2+的存在使KDTN与HSA的结合常数发生明显变化,结合位点仍接近1.  相似文献   

6.
在模拟的生理条件下,采用荧光发射光谱、紫外-可见分光光度法、同步荧光光谱、三维荧光光谱和圆二色(Circular dichroism,CD)光谱等技术研究了灿烂甲酚蓝(Brilliant cresyl blue,BCB)与人血清白蛋白(Human serum albumin,HSA)的结合性质以及药物的结合对HSA构象的影响.结果表明,BCB和能猝灭HSA的内源荧光,BCB对HSA的荧光猝灭是形成HSA-BCB复合物的静态猝灭过程,紫外-可见吸收光谱的结果也进一步证实了BCB对HSA荧光的静态猝灭.BCB与HSA分子Trp残基的距离r小于7 nm,说明HSA与BCB之间能够发生非辐射能量转移,但由于rR0值,这说明形成HSA-BCB复合物导致的静态猝灭是HSA荧光猝灭的主要原因.热力学参数计算结果表明BCB与HSA相互作用形成HSA-BCB复合物的过程是自发进行的,疏水作用力和氢键在形成HSA-BCB复合物的过程中发挥主要作用.同步荧光光谱、三维荧光光谱和CD光谱的结果说明BCB与HSA的相互作用形成的HSA-BCB复合物导致了HSA的构象发生了变化.  相似文献   

7.
用荧光光谱、紫外光谱和圆二色谱法研究了抗凝血药物华发灵钠与人血清白蛋白(HSA)的相互作用.初步确定华法灵钠对人血清白蛋白的荧光产生猝灭现象,猝灭方式为静态,并计算了二者形成化合物的结合常数K和结合位点数n.根据不同温度下的热力学函数,确定了华发灵钠与人血清白蛋白的相互作用力类型为氢键和范德华力.发现华法灵钠的存在明显改变人血清白蛋白的构象,并讨论了华发灵钠使人血清白蛋白构象发生变化的可能原因.  相似文献   

8.
利用荧光光谱法以及分子对接计算研究了橙皮素同人血清白蛋白(HSA)间的相互作用,并将结果同牛血清白蛋白(BSA)进行对比。实验结果表明,橙皮素均可以通过静态猝灭的方式有效地猝灭这2种蛋白质,且猝灭常数相近,猝灭效率差别很小。橙皮素与HSA结合位点数与BSA相同,但是结合常数小于BSA,并且同步荧光光谱数据显示橙皮素与BSA和HSA的相互作用使得这2种血清蛋白的结构发生了一些变化,从而导致荧光猝灭。分子对接计算表明,橙皮素同BSA及HSA的作用方式相似,都是在疏水及氢键作用驱动下结合在BSA或HSA部分氨基酸残基形成的疏水性口袋中。  相似文献   

9.
采用荧光光谱法研究了不同温度下氨甲苯酸与人血清白蛋白(HSA)的结合反应.结果表明:氨甲苯酸对HSA的荧光猝灭机制主要为静态猝灭,与HSA之间形成了1∶1的复合物,结合常数与结合位点数n分别为3.686×103,0.9253(298K)和1.671×103 L.mol-1.s-1,0.8982(310K),其作用力以氢键和范德华力为主.同步荧光光谱表明氨甲苯酸使色氨酸残基的疏水性减弱.  相似文献   

10.
用荧光猝灭法研究人血清白蛋白与吲哚美辛的结合反应   总被引:1,自引:1,他引:1  
应用荧光光谱法研究了吲哚美辛与人血清白蛋白(HSA)的相互作用. 发现吲哚美辛对HSA的荧光有较强的猝灭作用. 采用两种计算结合常数KA的方法, 并对两种计算方法进行比较. 探讨了温度对吲哚美辛与HSA结合反应的影响, 得到了不同温度下的结合常数 KA 与结合位点数n值. 进一步探讨了一些金属离子对吲哚美辛与HSA结合常数的影响. 根据热力学常数确定了它们之间的主要作用力类型.  相似文献   

11.
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   

12.
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   

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

14.
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   

15.
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   

16.
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   

17.
18.
The explosive growth of the Internet and database applications has driven database to be more scalable and available, and able to support on-line scaling without interrupting service. To support more client's queries without downtime and degrading the response time, more nodes have to be scaled up while the database is running. This paper presents the overview of scalable and available database that satisfies the above characteristics. And we propose a novel on-line scaling method. Our method improves the existing on-line scaling method for fast response time and higher throughputs. Our proposed method reduces unnecessary network use, i.e. , we decrease the number of data copy by reusing the backup data. Also, our on-line scaling operation can be processed parallel by selecting adequate nodes as new node. Our performance study shows that our method results in significant reduction in data copy time.  相似文献   

19.
R-Tree is a good structure for spatial searching. But in this indexing structure,either the sequence of nodes in the same level or sequence of traveling these nodes when queries are made is random. Since the possibility that the object appears in different MBR which have the same parents node is different, if we make the subnode who has the most possibility be traveled first, the time cost will be decreased in most of the cases. In some case, the possibility of a point belong to a rectangle will shows direct proportion with the size of the rectangle. But this conclusion is based on an assumption that the objects are symmetrically distributing in the area and this assumption is not always coming into existence. Now we found a more direct parameter to scale the possibility and made a little change on the structure of R-tree, to increase the possibility of founding the satisfying answer in the front sub trees. We names this structure probability based arranged R-tree (PBAR-tree).  相似文献   

20.
The geographic information service is enabled by the advancements in general Web service technology and the focused efforts of the OGC in defining XML-based Web GIS service. Based on these models, this paper addresses the issue of services chaining,the process of combining or pipelining results from several interoperable GIS Web Services to create a customized solution. This paper presents a mediated chaining architecture in which a specific service takes responsibility for performing the process that describes a service chain. We designed the Spatial Information Process Language (SIPL) for dynamic modeling and describing the service chain, also a prototype of the Spatial Information Process Execution Engine (SIPEE) is implemented for executing processes written in SIPL. Discussion of measures to improve the functionality and performance of such system will be included.  相似文献   

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