马钱子总生物碱缓释片处方和工艺的研究

以羟丙基甲基纤维素(HPMC)为骨架材料,制备马钱子生物碱缓释片,建立马钱子生物碱缓释片释放度的HPLC测定方法,并考察其体外释放度.采用HPLC测定马钱子生物碱缓释片的体外释放度,并对影响释药的因素进行了单因素考察.羟丙甲纤维素(HPMC)的规格和用量对释药速率有显著影响,马钱子生物碱缓释片的体外释放曲线基本符合Higuchi方程.本法制备的缓释片比普通片具有明显的缓释作用.该制备工艺简单易行,生产成本低,片剂外观及可压性良好.     

阿司匹林HPC骨架片实验研究

目的:研究以羟丙基纤维素(hydroxypropylcellulose,HPC)作为骨架材料,采用粉末直接压片法制备阿司匹林缓释片的方法.方法:根据预实验结果,采用正交设计进行处方设计和工艺优化,对按最优处方制备的样品进行质量考察.结果:优选的阿司匹林缓释片处方工艺合理,由其制备的缓释片体外释药2h释放度为26%～28%,4h释放度为51%～53%,8h释放度为89%～90%.样品经过两年稳定性考察质量稳定.结论:HPC为骨架材料制备阿司匹林缓释片工艺简单可行,骨架片体外释放效果良好,样品质量稳定.     

氯化钾-乙基纤维素骨架缓释片的制备及处方工艺优化

研制了氯化钾-乙基纤维素骨架缓释片并优化处方.以乙基纤维素10(以下简称EC)为缓释骨架材料,并以氢化植物油为润滑剂,乙醇为黏合剂,流化床制粒并制备氯化钾-EC骨架缓释片.在处方单因素考察的基础上,选择对缓释片释放行为影响较大的三个处方因素-EC微丸用量、氢化植物油用量、压片压力,以累计释放度为指标,利用正交实验设计L9(34)对缓释片进行优化,将自制的乙基纤维素-氯化钾缓释片与市售产品进行比较.结果表明在3因素中压片的压力对氯化钾-乙基纤维素骨架缓释片的释放度影响最大,最佳处方组成为5%EC占比48.75%,6%EC占比48.75%,氢化植物油2.50%,压片压力设置为30kN.自制的氯化钾-乙基纤维素骨架缓释片具有明显的缓释效果,并优于市售产品.     

盐酸奈福泮缓释片的制备和体外释放度

目的:研制盐酸奈福泮缓释片,并考察其体外释放度。方法:运用正交设计方法筛选缓释片的处方,通过释放试验评价缓释效果。结果:制备的缓释片在人为释放介质时可持续释药12 h,释放曲线符合Higuchi方程(r>0.99)。结论:以正交设计法优选的处方较合理,制备工艺较简单,制得的缓释骨架片具有较理想的缓释作用。     

熔融法制备盐酸二甲双胍缓释片及其稳定性考察

目的:制备盐酸二甲双胍缓释片并考察其稳定性.方法:以十八醇为骨架材料,采用熔融法制备盐酸二甲双胍缓释片,以体外释放度为评价指标,正交试验设计优化处方,并对制剂进行稳定性考察.结果:十八醇用量和加热温度显著影响盐酸二甲双胍释药速率.优化处方下制备的缓释片体外释放曲线10h内符合Higuchi方程,24个月内主药含量、释放度、有关物质及其他检查项目未见明显变化.结论:通过使用适量十八醇,可获得具有理想释药行为的盐酸二甲双胍缓释片,该制剂稳定性良好.     

烟酰水杨酸缓释片制备工艺及体外释放性的研究

制备烟酰水杨（Nicofinylsalicylic acid，NSA）缓释片，对其释放度进行研究，并确定其工艺流程和制备方法。采用转篮法考察缓释片的释放度，以高效液相色谱法（HPLC）测定烟酰水杨酸缓释片的累积释放浓度，并进行释放机制的研究。烟酰水杨酸缓释片的体外释放符合Higuchi方程。缓释片处方合理，工艺简单，相对于其普通片释药延长。体外释放度实验结果表明制备的烟酰水杨酸缓释片具有缓释作用。     

芦丁壳聚糖缓释片体外释放度研究

以壳聚糖为骨架材料制备芦丁壳聚糖缓释片,并用高效液相色谱法考察其体外释放度.结果芦丁壳聚糖缓释片在30min、60min、120min、180min、240min、360min、480min、720min的体外释放度为(11.37±0.96)%、(18.66±1.09)%、(28.26±0.94)%、(35.72±1.22)%、(41.37±1.20)%、(53.22±1.20)%、(60.66±0.85)%、(75.39±1.32)%.壳聚糖对芦丁具有缓释作用,药物的体外释放符合Higuchi方程.     

盐酸雷尼替丁胃内滞留漂浮型缓释片研制以及犬体内药物动力学

制备了24h盐酸雷尼替丁胃内滞留漂浮型缓释片(RHRFSRT).以水凝胶骨架作为胃内滞留漂浮型缓释片材料处方,研究了制剂体外释放度,漂浮性能以及对制剂在犬体内的药物动力学进行了初步研究.实验结果表明RHRFSRT的累积释放百分率符合Higuchi方程;体内药物动力学参数为AUC＝25571.691ng·h/mL,MRT=5.2h,ρmax＝5867.98ng/mL,相对生物利用度为178.16%.该制剂制备工艺简单,质量稳定,可以延长体内滞留时间并能提高生物利用度.     

龙牙缓释片释放度测定及体外释药机制研究

测定龙牙缓释片体外释放度,考察体外释药机制.采用HPLC测定龙牙缓释片的释放度,并对其进行释药机制研究.龙牙缓释片中的成分齐墩果酸HPLC测定波长为210 nm,齐墩果酸在0.21～5.12μg之间呈良好的线性关系(r=0.999 9).药物体外释药模式符合Higuich方程.龙牙缓释片的释药机理为药物扩散和骨架溶蚀的协同作用.     

布洛芬缓释片处方筛选及释放度研究

目的制备布洛芬12h缓释片并进行体外释放度测定.方法选用丙烯酸树脂和羟丙甲纤维素作为缓释材料,采用湿法制粒制备缓释片,通过正交试验优选处方组成,并对最优处方进行释放度测定和体外释药模型拟合.结果按最优处方制得的缓释片体外释放满足要求.缓释片释药行为符合一级动力学方程.结论该缓释片处方设计合理,工艺重现性高,缓释效果好.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

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.     

A computer generator for randomly layered structures

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

海南岛地体及其毗邻陆缘晚中生代—新生代古地磁研究和构造演化

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。     

Exciton Seebeck in Molecular Systems

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     

Achieving Unusual States of Matter Under High Pressure

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     

《Chinese Science Bulletin》SUBJECT INDEX TO VOLUME 59(2014)

正~~     

An on-line scaling method for improving scalability of a database cluster

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.     

An improved R-tree based on childnode''s probability

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).     

Integrating GIS Web services based on mediating architecture

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.     

Tracking data management using topology of moving object database system for moving object constrained trajectory in LBS application

Advances in wireless technologies and positioning technologies and spread of wireless devices, an interest in LBS (Location Based Service) is arising. To provide location based service, tracking data should have been stored in moving object database management system (called MODBMS) with proper policies and managed efficiently. So the methods which acquire the location information at regular time intervals then, store and manage have been studied. In this paper, we suggest tracking data management techniques using topology that is corresponding to the moving path of moving object. In our techniques, we update the MODBMS when moving object arrived at a street intersection or a curved road which is represented as the node in topology and predict the location at past and future with attribute of topology and linear function. In this technique, location data that are corresponding to the node in topology are stored, thus reduce the number of update and amount of data. Also in case predicting the location,because topology are used as well as existing location information, accuracy for prediction is increased than applying linear function or spline function.