The present paper covers a simple, reliable and reproducible method, based on capillary zone electrophoresis(CZE) with amperometric detection(AD), for the separation and the determination of ephedrine hydrochloride, p...The present paper covers a simple, reliable and reproducible method, based on capillary zone electrophoresis(CZE) with amperometric detection(AD), for the separation and the determination of ephedrine hydrochloride, promethazine hydrochloride and codeine phosphate. Under the optimal conditions, the three analytes were base-line separated completely within 16 min. Good linear relationships between the peak heights and the concentrations of the three analytes were obtained with the correlation coefficients better than 0 9993. The method was directly applied to the determination of the active ingredients in pharmaceutical preparations and the assay results were satisfactory.展开更多
Evidence seems to show that coding DNA is more random than noncoding DNA, but other conflictingevidence also exists. Based on the third-base degeneracy of codons, we regard the third position of codons as a 'noisy...Evidence seems to show that coding DNA is more random than noncoding DNA, but other conflictingevidence also exists. Based on the third-base degeneracy of codons, we regard the third position of codons as a 'noisy'position. By deleting one fixed position of non-overlapping triplets in a given sequence, three masked sequences may bededuced from the sequence. We have investigated the block-to-site mutual information functions of coding and noncodingsequences in yeast without and with the masking. Characteristics that distinguish coding from noncoding DNA havebeen found. It is observed that the strong correlations in the coding regions may be blocked by the third base of codons,and the proper masking can extract the correlations. Distribution of dimeric tandem repeats of unmasked sequences isalso compared with that of masked sequences.展开更多
基金Supported by the Key L aboratory of Electroanalytical Chemistry,Changchun Institute of Applied Chem istry of Chi-nese AcademyofSciences
文摘The present paper covers a simple, reliable and reproducible method, based on capillary zone electrophoresis(CZE) with amperometric detection(AD), for the separation and the determination of ephedrine hydrochloride, promethazine hydrochloride and codeine phosphate. Under the optimal conditions, the three analytes were base-line separated completely within 16 min. Good linear relationships between the peak heights and the concentrations of the three analytes were obtained with the correlation coefficients better than 0 9993. The method was directly applied to the determination of the active ingredients in pharmaceutical preparations and the assay results were satisfactory.
基金the Special Funds for Major National Basic Research Projects，国家自然科学基金
文摘Evidence seems to show that coding DNA is more random than noncoding DNA, but other conflictingevidence also exists. Based on the third-base degeneracy of codons, we regard the third position of codons as a 'noisy'position. By deleting one fixed position of non-overlapping triplets in a given sequence, three masked sequences may bededuced from the sequence. We have investigated the block-to-site mutual information functions of coding and noncodingsequences in yeast without and with the masking. Characteristics that distinguish coding from noncoding DNA havebeen found. It is observed that the strong correlations in the coding regions may be blocked by the third base of codons,and the proper masking can extract the correlations. Distribution of dimeric tandem repeats of unmasked sequences isalso compared with that of masked sequences.
