[Periphytic Algae Community Structure and Its Relation to Environment Factors in the Main Stream of the Songhua River from 2014 to 2019].

Periphytic algae are often used as an indicator to evaluate water quality. Here, the community structure of periphytic algae and its relationship with environment factors were analyzed in the main stream of the Songhua River during the summers of 2014 to 2019. The status and trends in ecological water quality were also evaluated based on bioassessments. Phytoplankton species belonging to 4 phyla and 58 genera were recorded, including 28 Bacillariophyta genera, 17 Chlorophyta genera, 10 Cyanophyta genera, and 3 Euglenophyta genera; Bacillariophyta, Chlorophyta, and Cyanophyta accounted for 48.28%, 29.31%, and 17.24% of the community, respectively. Cell densities varied between 1.29×104 and 8.42×104 ind·cm-3, with an average of 4.35×104 ind·cm-3. The dominant genera were Cyclotella, Melosira, Asterionella, Cymbella, Synedra, Pinnularia, Navicula, and Scenedesmus. The physicochemical water quality showed notable changes during the past six-year monitoring period. Specifically, the dissolved oxygen content increased year on year; ammonia nitrogen, total phosphorus, and total nitrogen first increased and then decreased; and, overall, water quality significantly improved in 2019. Relationship between periphytic algae and environmental factors was further examined using redundancy analysis (RDA), which showed that time was the main factor driving the succession of algal community structure. Dissolved oxygen (DO), ammonia nitrogen (NH4+-N), total nitrogen (TN), total phosphorus (TP), five-day biochemical oxygen demand (BOD), and chemical oxygen demand (COD) were also important environmental variables affecting algal community structure.

Study on application of bioassay method in drug-release evaluation in vitro of Salvia miltiorrhiza hydrophilic gel matrix tablets / 中国中药杂志

To investigate the feasible application of the bioassay method in the evaluation of traditional Chinese medicine sustained-release preparations, develop a rapid drug-release evaluation method in vitro for multi-component preparations, and replace the biological activity determination method characterizing the overall behavior with the existing drug-release evaluation method for single component, in order to give better instruction for sustained-release preparations. HPLC was adopted to determine dissolution media, drug releasing rates, and accumulative releasing of active ingredients (salvianolic acid B, protocatechuic aldehyde and rosmarinic acid) of Salvia Miltiorrhiza hydrophilic gel matrix tablets. The ultraviolet spectroscopy was adopted to determine the antioxidant activity of release media, and evaluate the correlation between the drug-time curve of various drug components and the drug-time curve of the total antioxidant activity. The correlation coefficient between the drug-release curve of various components and the drug-time curve of the total antioxidant activity was higher than the critical value r 0.898 (P < 0.001). This indicated that the drug-release curve of the three phenolic acids and the drug-time curve of the total antioxidant activity had a good correlation in different conditions, such as dissolution media, release rates and component ratios. The bioassay method for determination was feasible, simple and convenient for preparation quality evaluation and prescription design in the place of in vitro dissolution.