阿霉素凝胶体外释放度的测定

建立阿霉素凝胶的制备方法,并考察其体外释放度。采用紫外分光光度法,恒温空气浴摇床装置(温度为37℃±0.5℃,转速为50r/min),以pH7.4的PBS为溶出介质测定阿霉素凝胶的释放度,检测波长为254nm。阿霉素凝胶在24h内释放较快,体外释放率达到56.67%左右,随后可持续稳定释药,释放时间可达到7天以上。阿霉素凝胶体外释放性能良好,具有明显的缓释作用。     

落球法测定重力加速度的新方法

在用落球法测定重力加速度的实验中, 提出借助数码相机拍视频替代计时器来测定重力加速度的方 法. 结果显示, 由该方法测得的g值与参考值之间的相对误差小于2%, 说明借助照相机拍视频方法测定重力加速 度的方法是可行的. 该方法所需实验器材简单易得, 步骤简单, 操作性强, 是一个可以在教学过程中实施测定重力 加速度的新方法     

油茶皂苷-干酪素控释片的制备及其性能研究

以油茶皂苷为主药,采用干酪素和瓜尔豆胶为控释辅料,制备油茶皂苷-干酪素控释片。研究油茶皂苷-干酪素片中油茶皂苷含量的测定方法、溶出介质对油茶皂苷-干酪素控释片释放度的影响及油茶皂苷-干酪素控释片的红外光谱,并对油茶皂苷-干酪素片体外释放动力学方程进行拟合。用香草醛-浓硫酸显色法测定pH 6.8的磷酸盐缓冲溶液作为释放介质时油茶皂苷-干酪素片中油茶皂苷的含量,回收率为98.59%。油茶皂苷-干酪素控释片在pH 6.8的磷酸盐缓冲液中,释放时间分别为3,6和12h时,其释放度分别为:23.80%,51.26%和94.77%。体外释药曲线与零级方程拟合相关性较好,相关系数(R2)为0.996。油茶皂苷、干酪素和瓜尔豆胶之间可能形成了化学键。     

雷公藤胃漂浮缓释胶囊的制备及体外释放度的考察

制备了雷公藤胃漂浮缓释胶囊,对其释放机制进行考察.建立HPLC法考察其体外释放度,以羟丙基甲基纤维素(HPMCK4M)为主要辅料,制备亲水凝胶型骨架胶囊,采用L9(34)正交试验筛选出胶囊的处方.所制备的胃漂浮缓释胶囊在12h内呈良好的零级释药特征;以正交试验设计的雷公藤胃漂浮缓释胶囊处方合理,体外释放性能良好.     

聚合物梯度折射率微球透镜的研制

选取高分子单体组合,用悬浮扩散共聚法研制具有球对称梯度折射率(Gradient Refractive Index,GRIN)的微型聚合物球透镜.用剪切干涉法测定微透镜试样的折射率剖面,根据分布曲线的特征调整、优化制备工艺条件,成功获得直径0.3～1.4 mm、透明、在半径的全程范围具有球对称折射率梯度,折射率差ΔN为0.006～0.014的微型聚合物球透镜.     

蒙特卡洛模拟漫辐射时两种确定表面发射方向方法的比较

介绍一种有效的确定能束发射方向的方法——切球法.分析传统方法和切球法确定发射方向的原理及实施过程,说明切球法更为方便.采用2种方法对一简单的几何模型的角系数进行蒙特卡洛计算,所得结果与文献中积分结果进行比较,说明了切球法的可行性,计算精度能满足工程要求.同时对2种方法的计算耗时进行比较,切球法可以节省计算时间.将切球法应用到复杂系统中其优越性将会得到更加充分体现.     

光学测试

光学元件测试与设备TB962007021784激光相位调制法布里-珀罗腔精细度法测定反射率=Measurement of reflectivity of optical mirrors using laserphase modulation and fineness of Fabry-Perot cavity[刊,中]/鲁红刚(华东师范大学物理系光谱学与波谱学教育部重点实验室.上海(200062)),蒋燕义…//中国激光.-2006,33(12).-1675-1679在谐振腔精细度方法的基础上引入激光相位调制技术,提出激光相位调制法布里-珀罗(F-P)腔精细度法测定反射率。利用电光调制器对激光进行射频相位调制,以产生的调制边带与激光载波的频率间隔作为“射频标尺”,…     

异烟肼乳酸-乙醇酸共聚物磁性微球的制备和体外释放

采用化学共沉法制备磁性Fe3O4纳米粒,再采用W/O/W复乳-溶剂挥干法制备异烟肼乳酸-乙醇酸共聚物[Poly(lactide-co-glycolide),PLGA]磁性微球(INH-PLGA-MMS);电镜考察INH-PLGA-MMS形态、激光粒径分析仪考察粒径分布、磁场计测定磁感应强度、高效液相色谱法(HPLC)测定包封率、载药量及其释放度。结果表明,W/O/W复乳-溶剂挥干法制得的INH-PLGA-MMS外观圆整、表面光滑,平均粒径为3.02μm,磁感应强度为11.403emu/g,平均包封率为62.52%,平均载药量为9.21%,体外释放表明该制剂具有明显的缓释功能,外加振荡磁场可以增加磁性微球中药物的释放。     

升球法测量变温液体粘滞系数

将传统落球法测定液体粘滞系数改为升球法进行试验,很好地控制小球上升匀速段,提高精度;同时配以激光光电计时器计时,使测量结果更加精准。另外,本套装置中配设水循环系统,室温和变温下的液体粘滞系数均可测量。     

球共振声学法测量普适气体常数

设计和建立了高精度的球共振声学法气体音速测量装置,分析了实际的球共鸣器的结构对共振频率的影响,并给予了相应的修正.测量了温度为29315K,压力在02MPa—08MPa范围内氩气的音速,并根据音速数据确定了普适气体常数.实验温度、压力和普适气体常数的不确定度分别为±14mK,±2kPa和±00036%.最终确定的普适气体常数R为831439±000030J·mol-1·K-1. 关键词： 普适气体常数 音速 球共振器 声学法     

Preparation of magnetic polylactic acid microspheres and investigation of its releasing property for loading curcumin

In order to obtain a targeting drug carrier system, magnetic polylactic acid (PLA) microspheres loading curcumin were synthesized by the classical oil-in-water emulsion solvent-evaporation method. In the Fourier transform infrared spectra of microspheres, the present functional groups of PLA were all kept invariably. The morphology and size distribution of magnetic microspheres were observed with scanning electron microscopy and dynamic light scattering, respectively. The results showed that the microspheres were regularly spherical and the surface was smooth with a diameter of 0.55-0.75 μm. Magnetic Fe₃O₄ was loaded in PLA microspheres and the content of magnetic particles was 12 wt% through thermogravimetric analysis. The magnetic property of prepared microspheres was measured by vibrating sample magnetometer. The results showed that the magnetic microspheres exhibited typical superparamagnetic behavior and the saturated magnetization was 14.38 emu/g. Through analysis of differential scanning calorimetry, the curcumin was in an amorphous state in the magnetic microspheres. The drug loading, encapsulation efficiency and releasing properties of curcumin in vitro were also investigated by ultraviolet-visible spectrum analysis. The results showed that the drug loading and encapsulation efficiency were 8.0% and 24.2%, respectively. And curcumin was obviously slowly released because the cumulative release percentage of magnetic microspheres in the phosphate buffer (pH=7.4) solution was only 49.01% in 72 h, and the basic release of curcumin finished in 120 h.     

Drug Controlled Release and Biological Behavior of Poly(D,L-Lactide-Co-Glycolide) Microspheres

Poly(D,L-lactide-co-glycolide) (PLGA, 75/25) microspheres loaded with bovine serum albumin (BSA) were prepared using the W/O/W emulsification solvent evaporation technique. The cytotoxicity in vitro of PLGA microspheres was investigated and the BSA release from PLGA microspheres was also studied. Scanning electron micrographs showed that the PLGA microspheres were regular and the surface was smooth. BSA release typically began with an initial burst and then became steady. Analysis of the PLGA microspheres cytotoxicity showed that they had no cytotoxic effect and behaved very similar to the negative control of polystyrene. The hemolysis rate of the PLGA microspheres was 0.148%, suggesting it had no potential to induce hemolysis. The results show that PLGA microspheres may provide a useful controlled release protein drug system for used in pharmaceutics.     

The Use of Weissler Method for Scale-Up a Kraft Pulp Oxidation by TEMPO-Mediated System from a Batch Mode to a Continuous Flow-Through Sonoreactor

The efficiency of cellulose oxidation mediated by the 4-acetamido-TEMPO radical under ultrasonic cavitation was investigated using two ultrasonic systems: a batch lab scale ultrasonic bath with a glass reactor and a semi-continuous flow-through sonoreactor. The main objective was to explore the possibility of scaling up the production of oxidized cellulose under ultrasound, from a lab scale process to a pilot plant process, which served as a precursor for producing nanofibrils cellulose. It was found that under acoustic cavitation, the efficiency of TEMPO-mediation oxidation of native cellulose was significantly improved, particularly in the flow-through sonoreactor. In comparison with the glass reactor, the flow-through sonoreactor reduce the applied energy by 88% while increasing 7.8 times the production rate of radicals. These results enable a possibility of producing oxidized fibers for industrial applications.     

微凝胶模板法制备P（AM-co-MAA）/ZnO有机-无机复合微球的研究

采用反相悬浮聚合法合成了甲基丙烯酸（MAA）含量不同的聚丙烯酰胺-甲基丙烯酸[P（AM-co-MAA）]微凝胶,并以其作为模板,通过外源沉积法制备了一系列微米级,表面具有纳米级颗粒堆积的P（AM-co-MAA）/ZnO有机-无机复合微球。复合微球的表面结构与微凝胶的组成和ZnO的沉积量有关。详细考察了MAA含量,Zn（Ac）2浓度,NaOH醇溶液的浓度对ZnO负载量的影响。利用扫描电子显微镜（SEM）,能谱分析仪（EDX）,X衍射分析仪（XRD）,傅里叶红外分析仪（FT-IR）等对复合微球的形貌、组成进行了表征。     

Sonochemical synthesis of liquid-encapsulated lysozyme microspheres

Liquid-encapsulated lysozyme microspheres were successfully synthesized using a sonochemical method. The encapsulation of four different liquids, namely, sunflower oil, tetradecane, dodecane and perfluorohexane on the formation, stability and morphology of the lysozyme microspheres was studied. Among the four different liquids used for encapsulation, perfluorohexane-filled microspheres were found to be most stable in the dried state with a narrow size distribution. In order to explore the possibility of encapsulating biofunctional molecules (e.g., drugs) within these microspheres, liquids containing a fluorescent dye (Nile red) were encapsulated and the ultrasound-induced release of these dye-loaded liquids was studied. The fluorescence data for the liquid-filled lysozyme microspheres demonstrated the potential use of the sonochemical technique for synthesizing these “vehicles” for the encapsulation and the controlled delivery of dyes, flavours, fragrances or drugs.     

土壤中无机砷测定的三种前处理方法比较

对土壤无机砷分析的样品前处理技术-微波辅助提取、超声波提取、水浴提取进行了对比研究.结合氢化物发生-原子荧光光谱(HG-AFS)测定技术比较了3种方法对国家土壤标准物质中无机砷的提取效果,并对溶剂类型、提取时间和提取剂用量等影响因素进行了考察.与超声波提取法和水浴提取法相比,微波辅助提取法具有快速、高效的优势.     

Automated measurement and classification of pulmonary blood-flow velocity patterns using phase-contrast MRI and correlation analysis

An automated method was evaluated to detect blood flow in small pulmonary arteries and classify each as artery or vein, based on a temporal correlation analysis of their blood-flow velocity patterns. The method was evaluated using velocity-sensitive phase-contrast magnetic resonance data collected in vitro with a pulsatile flow phantom and in vivo in 11 human volunteers. The accuracy of the method was validated in vitro, which showed relative velocity errors of 12% at low spatial resolution (four voxels per diameter), but was reduced to 5% at increased spatial resolution (16 voxels per diameter). The performance of the method was evaluated in vivo according to its reproducibility and agreement with manual velocity measurements by an experienced radiologist. In all volunteers, the correlation analysis was able to detect and segment peripheral pulmonary vessels and distinguish arterial from venous velocity patterns. The intrasubject variability of repeated measurements was approximately 10% of peak velocity, or 2.8 cm/s root-mean-variance, demonstrating the high reproducibility of the method. Excellent agreement was obtained between the correlation analysis and radiologist measurements of pulmonary velocities, with a correlation of R2=0.98 (P<.001) and a slope of 0.99+/-0.01.     

Continuous contact- and contamination-free ultrasonic emulsification-a useful tool for pharmaceutical development and production

A novel concept was developed here for the continuous, contact- and contamination-free treatment of fluid mixtures with ultrasound. It is based on exciting a steel jacket with an ultrasonic transducer, which transmitted the sound waves via pressurised water to a glass tube installed inside the jacket. Thus, no metallic particles can be emitted into the sonicated fluid, which is a common problem when a sonotrode and a fluid are in direct contact. Moreover, contamination of the fluid from the environment can be avoided, making the novel ultrasonic flow-through cell highly suitable for aseptic production of pharmaceutical preparations. As a model system, vegetable oil-in-water emulsions, fed into the cell as coarse pre-emulsions, were studied. The mean droplet diameter was decreased by two orders of magnitude yielding Sauter diameters of 0.5 microm and below with good repeatability. Increasing the residence time in the ultrasonic field and the sonication power both decreased the emulsion mean diameter. Furthermore, the ultrasonic flow-through cell was found to be well suited for the production of nanoparticles of biodegradable polymers by the emulsion-solvent extraction/ evaporation method. Here, perfectly spherical particles of a volume mean diameter of less than 0.5 microm could be prepared. In conclusion, this novel technology offers a pharmaceutically interesting platform for nanodroplet and nanoparticle production and is well suited for aseptic continuous processing.     

Silver–titanium dioxide nanocomposites as effective antimicrobial and antibiofilm agents

Recent studies have revealed the existence of liver cancer stem cells (CSCs). Therefore, there is an urgent need for new and effective treatment strategies specific to liver CSCs. In this work, the poly(d,l-lactide-coglycolide) nanoparticles containing paclitaxel were prepared by emulsification-solvent evaporation method. The nanoparticles decorated with anti-CD133 antibody, termed targeted nanoparticles, were prepared by carbodiimide chemistry for liver CSCs. The physicochemical characteristics of the nanoparticles (i.e., encapsulation efficiency, particle size distribution, morphology, and in vitro release) were investigated. Cellular uptake and accumulation in tumor tissue of nanoparticles were observed. To assess anti-tumor activity of nanoparticles in vitro and in vivo, cell survival assay and tumor regression study were carried out using liver cancer cell lines (Huh7 and HepG2) and their xenografts. Particle size of targeted nanoparticles was 429.26 ± 41.53 nm with zeta potential of ?11.2 mV. Targeted nanoparticles possessed spherical morphology and high encapsulation efficiency (87.53 ± 5.9 %). The accumulation of targeted nanoparticles depends on dual effects of passive and active targeting. Drug-loaded nanoparticles showed cytotoxicity on the tumor cells in vitro and in vivo. Targeted nanoparticles resulted in significant improvement in therapeutic response through selectively eliminating CD133 positive subpopulation. These results suggested that the novel nanoparticles could be a promising candidate with excellent therapeutic efficacy for targeting liver CSCs.