Application of liquid pre-column capillary electrophoresis technique to the study of interaction between drug enantiomers and human serum albumin

Based on the chiral separation of several basic drugs, dimetindene, tetryzoline, theodrenaline and verapamil, the liquid pre-column capillary electrophoresis (LPC-CE) technique was established. It was used to determine free concentrations of drug enantiomers in mixed solutions with human serum albumin (HSA). To prevent HSA entering the CE chiral separation zone, the mobility differences between HSA and drugs under a specific pH condition were employed in the LPC. Thus, the detection confusion caused by protein was totally avoided. Further study of binding constants determination and protein binding competitions was carried out. The study proves that the LPC technique could be used for complex media, particularly the matrix of protein coexisting with a variety of drugs.

管理干部胜任特征评价方法的初步研究

Competency Assessment Method (CAM) is an important technique of Human Resource Management and Development in theory and practice, especially in personnel selection and training. Based on literatures of related fields, the thesis explored the feasibility of CAM in China. The main results found in this study are as follows: 1. Competencies scored in Behavioral Event Interviews (BEI) are not influenced by length of protocol, by performance in the preceding year. Average level and maximal level of complexity correlate significantly with length of protocol. Total competency frequency of outstanding executives is not significantly different from that of typical executives. These results support McCleland's view. But there is significant correlation between length of protocol and competency frequencies, which which is not agreed by McCleland. We found that competency scores using coding standard of average level and maximal level of complexity show more reliability than that using coding standard of competency frequencies. But this isn't confirmed by McCleland. 2. Inter-rater reliability was studied. The results indicated: total Category Agreement (CA) is 55.45%, over 70 percent of 20 competencies of the inter-rater reliability coefficients based on the classical test theory are significantly correlated. G coefficient based on the generalization theory is 0.85697. 3. Study of criterion sample shows that manager's competencies of China's communication enterprise are as follows: Impact and Influence, Organization Commitment, Information Seeking, Achievement Orientation, Team Leadership, Interpersonal Understanding, Initiative, Market Awareness, Self-confidence, Developing Others. This result in similar to the generic competency model of managers presented in Spencer's book. 4. CAM showed more advantages than the method of experts panel judgement.

Column switching-back flushing technique for the analysis of aromatic compounds in gasoline

A simple method, based on the technique of capillary column switching-back flushing, has been developed for the detailed analysis of aromatic compounds in gasoline. The sample was first separated on a 30-m long OV-2330 polar precolumn and then backflushed onto a nonpolar analytical column. The early eluting components from the precolumn and the components of interest (aromatic compounds plus heavier compounds) eluting from the analytical column are all directed to the same flame ionization detection system through a T piece, which permits the quantitative analysis of aromatic hydrocarbons in gasoline by a normalization method using correcting factors. The switching time window of the method is +/-5 s, resulting in easier operation and higher reliability. The reproducibility of the quantitative analysis was less than or equal to3% RSD for real gasoline samples. (C) 2002 Elsevier Science B.V. All rights reserved.