首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 62 毫秒
1.
目的:通过对青蒿素脂质体的处方和制备工艺研究,研制高包封率和稳定的脂质体。方法:采用乙醇注入法制备脂质体,以正交实验优化处方,测定了脂质体中药物的包封率,并初步考察了脂质体的稳定性。结果:优化处方与工艺所得脂质体形态均匀,包封率大于85%,载药量达27.22%,粒径约为90 nm,Zeta电位约为-68.4 mV,具有良好的稳定性。结论:乙醇注入法制备脂质体工艺简便,包封率高,制备的脂质体稳定好。  相似文献   

2.
采用逆向蒸发法制备了稳定的溶菌酶脂质体.在不锈钢表面培养出稳定生物膜后,分别利用溶菌酶和溶菌酶脂质体对其进行剥离.运用Zeta电位仪、扫描电子显微镜(SEM)和红外光谱(FT-IR)对脂质体和生物膜进行表征.结果表明制备的脂质体平均粒径为80~100 nm,包封率为82.4%.相同浓度下溶菌酶及其脂质体对混合菌种形成的生物膜剥离效率分别达到62.4%和86.5%.溶菌酶脂质体在24h内对生物膜和水体中微生物去除率分别达到89.6%和99.6%.因此,溶菌酶脂质体能够有效控制不锈钢表面生物膜污染风险.  相似文献   

3.
研究菊苣酸脂质体的最佳制备工艺。采用薄膜分散-超声法制备菊苣酸脂质体,以包封率为评价指标,采用Box-Behnken design响应面优化法优化制备工艺参数。结果显示最佳制备工艺为:磷脂与胆固醇的质量比为4.20:1,磷脂与药物的质量比为11.44:1,超声时间为6.54 min,采用最优工艺制备的脂质体包封率为75.18%。采用Box Behnken design响应面法优选出了最佳制备工艺,所得工艺合理可行。  相似文献   

4.
采用逆相蒸发法制备更昔洛韦脂质体,同时对所制脂质体进行了表征和稳定性分析.采用透射电镜观察其形态;采用激光粒度仪测定平均粒径;用葡聚糖凝胶层析柱分离含药脂质体和游离药物并测定包封率;用离心加速试验及室温冷藏法考察脂质体的稳定性.结果表明,得到的更昔洛韦脂质体的平均粒径为332.3 nm,多相分散系数为0.143,包封率为43.24%,在考察时间段内,所制脂质体稳定性良好.  相似文献   

5.
氟比洛芬脂质体的制备及其载药性能研究   总被引:1,自引:0,他引:1  
利用薄膜蒸发-超声分散法制备氟比洛芬脂质体,通过鱼精蛋白凝聚法测定脂质体对氟比洛芬的包封率和载药率,研究了氟比洛芬脂质体载药性能的影响因素.结果表明,制得的氟比洛芬脂质体的粒径为100~250 nm,具有良好的分散性;氟比洛芬定位于脂质体的疏水基团区域,它在卵磷脂相和水相中的分配系数KD为815.6.当卵磷脂浓度为5.4×10-4mol.L-1时,所得脂质体对氟比洛芬的包封率和载药率比较理想;随着氟比洛芬与卵磷脂的质量比的增加,脂质体对氟比洛芬的载药率增大,包封率降低;胆固醇可以调节脂质体膜的稳定性,胆固醇与卵磷脂的质量比应该控制在0.3以下,过高浓度的胆固醇会大量插入膜内使得膜的刚性增强,导致脂质体对氟比洛芬的载药率和包封率降低.  相似文献   

6.
脂质体转移因子的制备及其活性研究   总被引:8,自引:0,他引:8  
以转移因子为包裹对象,探讨提高脂质体肽类药物的包封率和减缓渗漏率的方法和条件,以及制备过程对活性的影响。采用逆相蒸发法制备、以正交试验设计筛选最佳配方组合,制备负电荷脂质体转移因子。通过巨噬细胞吞噬试验和E-玫瑰花结试验比较不同剂型、不同给药途径对小鼠免疫功能的影响。结果表明:负电荷脂质体转移因子包封率和稳定性均比其他文献报道的有较大的提高,包封率5次平均达43%,30d渗漏率12%,具有一定的稳定性;E-玫瑰花结试验显示:制备过程对转移因子活性无显著影响;巨噬细胞吞噬试验表明:不论注射或口服脂质体转移因子,均有提高机体免疫功能的作用,脂质体转移因子的药效优于游离转移因子。  相似文献   

7.
盐酸小檗碱脂质体的制备工艺研究   总被引:3,自引:0,他引:3  
采用薄膜蒸发法制备盐酸小檗碱脂质体,紫外分光光度———透析法测定脂质体包封率;以盐酸小檗碱脂质体包封率为指标,考察影响脂质体包封率的各因素.结果表明,制备盐酸小檗碱脂质体的最佳条件为孵化温度60℃,孵化时间30 m in,胆固醇3.3 mg.mL-1,此时包封率达到最高,且脂质体的包封率随着卵磷脂浓度的增加呈线性增加.  相似文献   

8.
采用冷冻干燥法制备茶多酚前体脂质体,并对其稳定性进行研究。通过考察冷冻保护剂的种类、冷冻保护剂的用量、预冻时间、冷冻干燥时间等因素对茶多酚前体脂质体复水后包封率的影响。在最佳制备工艺条件下:海藻糖为冷冻保护剂,海藻糖与卵磷脂的质量比为4∶1,预冻时间为6h,冷冻干燥时间为36h,制备得到的茶多酚前体脂质体复水后包封率45.5%,稳定性高。该法制备的茶多酚前体脂质体包封率高,稳定性好,可以长时间贮藏。  相似文献   

9.
禽流感病毒核酸疫苗脂质体的研究   总被引:4,自引:0,他引:4  
:用逆相法、脂膜法制得了禽流感病毒血凝素 (HA)基因重组质粒pSVH7DNA(核酸疫苗 )脂质体 ;用荧光法测定了质粒DNA脂质体的包封率 ,两种方法所得脂质体的包封率分别为 15 .5 8± 1.5 5 % ,6.0 8±0 .3 5 % ,当在磷脂成份中加入阳离子十八胺时 ,脂质体的包封率分别为 70 .4 1± 6.4 9% ,4 6.5 6± 1.92 % 磷脂浓度和离子强度均能影响脂质体的包封率 ,前者能增加包封率 ,而后者使其减少 电镜结果表明 ,两种方法所得的脂质体为单室或多室球形脂质体混合物 ,其粒径大小分别为 163nm和 2 3 5nm  相似文献   

10.
乙醇注入法制备司帕沙星脂质体   总被引:4,自引:0,他引:4  
制备司帕沙星脂质体,单因素考察优化了制备工艺和处方,以提高脂质体的包封率.采用乙醇注入高压均质法制备了司帕沙星脂质体,以透析高效液相色谱法测定了含量和包封率.实验结果表明,司帕沙星脂质体的平均粒径为22.1nm,包封率为47%左右.乙醇注入高压均质法适用于制备司帕沙星脂质体,透析高效液相色谱法操作简单、准确、重复性好,可用于测定司帕沙星脂质体的含量和包封率.  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.
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   

18.
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   

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   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号