Comparison study of chitosan/β-cyclodextrin and carboxymethyl chitosan/β-cyclodextrin microspheres

To compare two microspheres of chitosan/β-cyclodextrin and carboxymethyl chitosan/β-cyclodextrin loaded theophylline as pulmonary sustained drug delivery carriers, the characteristics and ciliotoxicity were studied. The drug loadings of chitosan/β-cyclodextrin and carboxymethyl chitosan/β-cyclodextrin microspheres were 21.09% and 21.42%, and the encapsulation efficiencies were 91.40% and 92.80%. The distributions of 50% (d _0.5) of chitosan/β-cyclodextrin and carboxymethyl chitosan/β-cyclodextrin microspheres were 4.89 and 5.83 μm, respectively. Both microspheres showed spherical shape with smooth or wrinkled surfaces. FT-IR of chitosan/β-cyclodextrin microspheres demonstrated that theophylline had formed hydrogen bonds with chitosan and β-cyclodextrin, while for the carboxymethyl chitosan/β-cyclodextrin microspheres theophylline had interaction with carboxymethyl chitosan. The moisture absorption showed that an equilibrium was reached within 24 h. The two microspheres possessed better adaptability. In vitro release of theophylline from chitosan/β-cyclodextrin microspheres was slower than that from carboxymethyl chitosan/β-cyclodextrin microspheres at pH 6.8. Biography: LI Ruobao(1968–), male, Associate professor, research direction: foundation research of respiratory system.     

中国苏北预先导孔CCSD-PP2片麻岩中锆石的矿物包裹体及其超高压变质作用的证据

采用激光Raman及阴极发光技术，确认中国大陆科学钻探工程预选预先导孔CCSD－PP2几乎所有类型片麻岩中的锆石均保存典型的柯石英包体以及绿辉石、硬玉、石榴石、多硅白云母等矿物包体，表明片麻岩类岩石曾普遍经历了超高压变质作用，该成果对于重新探讨苏鲁超高压变质带的俯冲－折返机制和对中国大陆科学钻探工程的选址有重要的科学意义。     

Behavior and adrenal activity in a group of zoo golden snub-nosed monkeys, Rhinopithecus roxellana, following social structure change

The effects of individual removal by zoo managers on behavior and fecal glucocorticoid changes in snub-nosed monkeys(Rhinopithecus roxellana) were investigated at Beijing Zoo.The results showed that the effect of the removal of three subordinate individuals(DD,male,4 years;XZZ,male,3 years and LL,female,3 years) from a group varied across the remaining group members that may be related to individual’s social status,gender and age.The dominant male was impacted less than subordinate individuals in both the frequency and time duration for the four main behavioral categories.The frequency of stereotypic behavior significantly decreased in the dominant female after the removal of three animals(Z= 2.862,P=0.003).Fluctuations were found in both the behavioral frequency and time duration in other remaining individuals.These findings suggest that small,socially stable groups were somewhat resilient to changes in member composition.Moreover,the cortisol level did not change significantly in the remaining members.An alternative method of hormone assay using fecal samples for vulnerable animals was presented,and that may be useful for monitoring wild golden monkeys and other endangered species of animal.     

市政工程建设项目施工技术方案优化

文章针对工程建设项目施工技术方案的分类和内涵进行了定义论述，提出了施工技术方案优化的目的、原则、方法与程序。     

应用平台维护初探

信息技术的日新月异使得信息化进程大为加快，应用系统也面临着集中度高、重要性强的特点。如何能保证应用系统平稳高效运行成为一个重要的课题。文章仅从应用系统平台的方面来讨论如何加强管理。     

一种基于555集成电路的恒温器设计

文章通过对555电路的分析，结合双向可控硅和运放F007的特性进行恒温电路设计。     

科学发展观视域下的经济法探微

科学发展观是崭新的哲学理论，经济法是现代法律制度，虽然不在同一层次上，但是科学发展观与经济法具有一定的内在联系。科学发展观对经济法的立法、实施具有重要的指导意义，而经济法是实现科学发展观的主要制度性方法：     

高斯型Runge-Kutta方法研究

提出了一类高斯型Runge—Kutta公式的推导思想，并具体的给出了一个两点三阶高斯型Runge—Kutta公式，证明了高斯型Runge—Kutta公式的精度高于传统的对应的Runge—Kutta公式。     

In-situ cosmogenic 36Cl denudation rates of carbonates in Guizhou karst area

This study quantifies surface denudation of carbonate rocks by the first application of in-situ cosmogenic36Cl in China. Concentrations of natural Cl and in-situ cosmogenic36Cl in bare carbonates from Guizhou karst areas were measured with isotope dilution by accelerator mass spectrometer. The Cl concentration varied from 16 to 206 ppm. The 36Cl concentrations were in range of (0.8-2.4)106 atom g-1 , resulting in total denudation rates of 20-50 mm ka-1 that averaged over a 104-105 a timescale. The 36Cl-denudation rates showed roughly a negative correlation with the local mean temperature. This preliminary observation may suggest the variations of proportions of chemical weathering and physical erosion in denudation process, depending upon local climatic conditions.     

一次同余式组的两种求解方法

运用矩阵的初等变换法和不定方程求解法,给出了求解同余式组的两种简便方法.