静电液滴工艺对蛋白质微球载体形态的影响

目的制备蛋白质药物非注射给药载体。方法以生物相容性优良的海藻酸盐为载体材料，以血红蛋白为药物模型，通过设计凝胶浴配方，采用静电液滴形成工艺制备包封蛋白质药物的微球载体。结果微球球形度优良，粒径分布窄，蛋白质包封率达到95％。结论采用静电液滴工艺实现了蛋白质在海藻酸盐微球中的高效包封，为在微球表面形成均匀控释膜、制备粒径≤10μm蛋白盾药物的口服给药微球裁体奠定了基础．     

壳聚糖-海藻酸盐微球在体检测方法探讨

为了研究壳聚糖-海藻酸盐微球在体内的转运、吸收与降解特性,探讨了微球在体检测可以采取的方法：放射性同位素示踪法和荧光探针标记法,其中荧光探针标记法方便、安全、检测灵敏性高。采用荧光素异硫氰酸酯（FITC）作为荧光标记化合物,在碱性条件下与壳聚糖共价结合,标记了FITC的壳聚糖在酸性条件下与海藻酸盐凝胶珠通过静电作用络合,达到荧光素FITC对壳聚糖-海藻酸盐微球荧光标记的目的,通过标准仪器检测FITC对微球进行示踪实验。     

载肝素钠ACA微胶囊载药量

采用乳化固化法制备粒径为820nm的海藻酸钙微球,同时采用两步成囊的方法在微球表面包覆几丁聚糖半透膜并制备海藻酸钙/几丁聚糖微胶囊.以肝素为模型药物,考察微球溶胀与非溶胀、加药浓度、载药方式、几丁聚糖相对分子质量、成膜时间、成膜液浓度、几丁聚糖改性物等因素对载药的影响.研究结果表明:所制备的微胶囊载药量最高可达77.4%.     

油包水微乳液介质中脂肪酶催化α-单硬脂酸甘油酯水解反应活性研究

以α-单硬脂酸甘油酯为底物研究油包水（W／O）微乳液介质中脂肪酶的水解催化活性。结果表明，由AOT／水／正庚烷构成的ω/O微乳液体系的w0值、pH值、缓冲液离子浓度、AOT浓度等参数对脂肪酶催化活性有影响，最佳酶活力对应的微乳液组成为：w0=8;pH=7.17(67mmol/L的KH2PO4－Na2HPO4缓冲液）；[AOT]=0.10mmol/L。研究还表明，微乳液介质中，脂肪酶催化α-单硬脂酸甘油酯水解反应动力学与水介质中相类似；当酶浓度恒定时，反应速率与底物浓度的关系符合Michaelis-Menten方程，最大反应速率vmax（用脂肪酶活力表示）约为156u,米氏常数Km约为5．6mmol/L；当底物浓度恒定时，反应速率与酶浓度成正比。     

互穿网络改性的蛋白质印迹海藻酸钙微球的制备与表征

为了改善海藻酸盐凝胶的离子交联强度较低、含水量高、凝胶稳定性差等不足.通过在海藻酸盐凝胶体系中添加少量纤维素醚(如羟乙基纤维素等)并使用戊二醛交联的方法,制备了互穿网络改性大分子及乳液双印迹海藻酸钙凝胶微球.微球机械强度和在0.9%氯化钠溶液中的抗溶胀性均有提高,振荡实验破损比例由24.4%降低为9.84%.红外光谱表明,改性组分戊二醛和羟乙基纤维素之间形成新的化学键,构成互穿网络结构.重结合实验表明,经过互穿网络改性的双印迹微球的印迹效率由2.19提高到2.70.离子交换色谱实验证实,改性微球的重结合分离系数由1.478提高到18.88.印迹重结合行为发生变化的原因可以归结为共价交联的互穿网络的形成和疏水性微环境的影响.共价交联的互穿网络可在一定程度上提高微球印迹结构的稳定性.增强对模板分子的特异性重结合能力.     

聚(α-氰基丙烯酸酯)共聚物载药微球的制备及其药物释放研究

以α-氰基丙烯酸异丁酯和α-氰基丙烯酸正辛酯为原料,泊洛沙姆188为表面活性剂,通过乳化法制备了聚(α-氰基丙烯酸酯)共聚物微球,然后通过共聚物微球对溶菌酶的吸附,制备了共聚物载药微球。考察了表面活性剂质量分数对微球粒径的影响,并就共聚物和药物的质量分数及吸附时间对微球粒径、载药率和负载率的影响进行了研究。结果表明:共聚物空白微球适宜的制备条件为,共聚物质量分数0.8%(α-氰基丙烯酸正辛酯与α-氰基丙烯酸异丁酯的物质的量比为1∶1),泊洛沙姆188质量分数1.0%,搅拌速度800r/min,体系pH2.5,反应时间3h;空白微球在pH7.0条件下进行溶菌酶吸附,在溶菌酶质量分数0.08%、吸附3h时所得的共聚物载药微球性能最佳,且所得的载药微球具有缓释特性。     

海藻酸钙季铵盐衍生物微球的制备及表征

采用乳化—凝胶法制备了海藻酸钙及其季铵盐衍生物微球,考察了海藻酸钠浓度、搅拌速度、油水比例、季铵盐浓度等因素对制备海藻酸钙季铵盐衍生物微球形态及粒径分布的影响.用红外光谱仪与光学显微镜对所制备的海藻酸钙季铵盐衍生物微球进行了表征.结果表明,通过对制备条件的优化,可制备出分布较均匀,形态较好的海藻酸钙季铵盐衍生物微球.     

5-氟尿嘧啶壳聚糖纳米微球的制备及表征

壳聚糖(CS)作载体,与三聚磷酸钠(TPP)和5-氟尿嘧啶(5-Fu)发生离子交联反应,制备具有缓释效能的5-氟尿嘧啶壳聚糖纳米微球,并以微球载药量、颗粒大小为指标设计优化了其制备方法,考察不同因数水平对微球的载药量的影响。用傅立叶红外光谱表征了其结构,用激光散射粒径仪测得微球的平均粒径为143~212 nm。氟尿嘧啶壳聚糖微球最大载药量为48.3%,在pH 7.1磷酸盐缓冲溶液中对氟尿嘧啶的缓释作用明显,释放周期较长,药物含量越大,药物从微球中释放出来的速率越快,可作为靶向药物控释体系。     

壳聚糖-海藻酸钙微球荧光标记反应对微球膜强度影响的研究

以壳聚糖-海藻酸钙载药微球给药后的体内检测为研究背景,探讨不同反应条件下壳聚糖-海藻酸钙微球荧光标记反应对微球膜在模拟体液中的强度影响.以壳聚糖、海藻酸钠为微球制备载体材料,以异硫氰酸酯(FITC)为荧光标记物对微球进行荧光标记.采用标记了FITC的微球在模拟体液中的膨胀率来表征微球膜的相对强度.采用相对分子质量为50 000、脱乙酰度85%、荧光标记浓度0.01 g/mL的壳聚糖,成膜液浓度0.015 g/mL,成膜时间30 min制备出的荧光微球在模拟胃、肠液中表现出良好的膜强度及稳定性.为研究壳聚糖-海藻酸钙载药微球在体内的分布、吸收、降解特性提供了适宜的入体实验条件.     

奥曲肽微球-凝胶复合体系的制备及加速释放

本研究旨在解决奥曲肽微球前期释放过程中的突释，将其设计成可注射的微球-凝胶复合体系。采用乳化溶剂挥发法制备奥曲肽微球，使用Box-Behnken响应面法对凝胶基质处方参数进行优化。通过考察pH、乙腈和乙醇浓度对该复合体系释药的影响，确定体外加速释放的条件，建立凝胶微球的体外加速释放方法。确定最优处方为：PL188、PL407和HPMC的质量分数分别为3%、22.2%和1%,成胶温度为37℃。该复合体系可有效减少微球前期突释，使药物释放行为更加稳定。确定体外加速释放条件为：含3%乙腈、6%乙醇、pH为7.4的PBS缓冲液为释放介质。该体外加速释放方法可快速有效评价复合体系的释放行为。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

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.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

A computer generator for randomly layered structures

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

An Index mechanism for multi-scale view in spatial databases

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.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the