Objective To select the best condition for microwave assisted extraction (MAE) of flavones from leaves of Ginkgo biloba L . and compare this method with the most conventional extraction way. Methods Both microwave assisted extraction and theat maceration were adopted for flavones from leaves of Ginkgo biloba L. , and the total content was determined by spectrophotometry. Results Under appropriate MAE conditions, both the recovery and purity of total flavones obtained from the experiments by uniform design and the orthogonal design were very similar. The optimal recovery and purity by orthogonal experimental design were 212 4 mg/g and 61 9%, respectively. The optimal results by orthogonal experimental design were 216 2 mg/g and 57 1%, respectively. However, the results by maceration were only 114 6 mg/g and 40 1%, respectively. Conclusion MAE is a more suitable method for the extraction of flavones from leaves of Ginkgo biloba L . because of its higher extraction rate and purity.

Objective To analyze and construct systolic blood pressure(SBP)fluctuation trajectory in a community population with hypertension and to analyze the factors influencing different trajectories.Methods This is a community-based retrospective cohort study.A latent class trajectory model was used to identify and construct longitudinal trajectories of blood pressure change.Multinomial logistic regression analysis was performed to identify the associated factors of blood pressure trajectories by adjusting for different confounders.Potential confounding factors were identified using a directed acyclic graph based on a priori knowledge.Results A total of 793 patients with hypertension were enrolled in the analysis.They were divided into 3 groups by LCTM-fitted systolic blood pressure trajectories,namely stable low-level group(n=561,70.74％),declining group(n=170,21.44％)and rising group(n=62,7.82％).Significant differences were observed among the 3 trajectories groups in terms of age,frequency of exercise,ways of follow-up,salt intake,compliance behavior,and referral(P＜0.05).Compared to the stable low-level group and adjusting for corresponding confounding factors,the male patients and the patients with"outpatient follow-up"were more likely to be classified into"declining group",with OR and 95％CI of 1.436(1.016～2.030)and 1.702(1.202～2.410),respectively.The participants aged ≥ 65 years,who did not exercise or occasionally exercised,and had moderate and severe salt intake,were more likely to be classified into the"rising group"(OR=1.949,2.284,2.433,4.540,95％CI:1.145～3.317,1.305～3.998,1.272～4.654,1.291～15.963).Conclusion SBP trajectories in community-dwelling hypertensive population can be divided into stable low-level,declining and rising groups.Gender,age,salt intake,exercise frequency,and follow-up methods may be influencing factors for SBP blood pressure trajectory.