OBJECTIVE:To optimize the extraction and purification technology of total flavonoids from Engelhardia roxburghi-ana,and to establish the method for the content determination of 3 kinds of effective components. METHODS:Using the extrac-tion transfer rate of astilbin as index,single factor test was used to investigate extraction solvent,extraction method,volume frac-tion of percolation solvent ethanol,percolation material-liquid ration,soaking time before percolation and percolation rate of extrac-tion technology,and volume fraction of eluant ethanol in AB-8 resin purification technology. The contents of 3 effective compo-nents as astilbin,texifolin and engelitin in total flavonoids from E. roxburghiana were determined by HPLC. RESULTS:The opti-mal extraction technology was using 70% ethanol as extraction and percolation solvent,percolation extraction,soaking for 8 h be-fore percolation,percolation material-liquid ratio of 1∶16(g/ml),percolation rate of 30 ml/(min·kg). The purification technology was diluting the solution to 0.5 g (crude drug)/ml with water,ethyl acetate extraction,dissolved extract with 50% ethanol after evaporated to dryness,AB-8 resin for sampling,eluted with 50% ethanol,concentrating and drying. In verification test,extraction transfer rate of astilbin was more than 80%(RSD=0.42%,n=3). The contents of astilbin,taxifolin and engeletin in total flavo-noids from E. roxburghiana by purified were 57.94%,3.72% and 2.83%,respectively;the contents of 3 components accounted for 64.00% of total flavonoids. CONCLUSIONS:The extraction and purification technology is stable,rational and reliable;the content determination method of 3 effective components in total flavonoids of E. roxburghiana is accurate,simple and producible.

Objective:To evaluate the feasibility and accuracy of a multi-dimensional peripheral quick contrast sensitivity function (pqCSF) measurement established based on Bayesian probability estimation algorithm.Methods:A cross-sectional study was conducted.Nineteen eyes of 12 healthy emmetropic subjects in Zhongshan Ophthalmic Center of Sun Yat-sen University from September 2017 to March 2018 were included, with an average age of (22.92±2.91) years.The average spherical power and cylindrical power were (-0.34±0.52)D and (-0.30±0.42)D, respectively, and the average uncorrected vision acuity was≥1.0.Based on the Bayesian probability algorithm, the peak contrast sensitivity γ max, the peak spatial frequency ? max, the bandwidth β and the low contrast intercept δ were used to quickly describe the contrast sensitivity function (CSF) curve of the full spatial frequency through multi-dimensional pqCSF method.The 16 peripheral visual field positions of all subjects were tested at 6°, 12°, 18° and 24° eccentricity of the superior, inferior, the temporal and nasal visual field by the pqCSF method, but the 18° eccentricity of temporal field, which was near the physiological blind spot, was excluded.The area under Log CSF (AULCSF) of different peripheral visual fields and the Log CSF of 19 spatial frequencies (distributed at equal intervals in logarithmic units) were compared.This study followed the Declaration of Helsinki, and the study protocol was approved by an Ethics Committee of Zhongshan Ophthalmic Center of Sun Yat-sen University (No.2018KYPJ017). Written informed consent was obtained from each subject prior to any examination. Results:With the increase of eccentricity in different visual fields, the AULCSF decreased gradually, and there were significant differences in AULCSF between different eccentricities (all at P<0.05). The AULCSF of the nasal and temporal visual field at 6°, 12° and 24° eccentricity was significantly larger than that of the superior and inferior visual field (all at P<0.05). As the distance from the fovea was increased, the pqCSF, the AULCSF, and the high-frequency cutoff were all decreased, and the standard deviation of AULCSF was increased gradually. Conclusions:The pqCSF method can depict a relatively complete peripheral CSF curve of a wide peripheral visual field, and reflect the function quality of the peripheral vision comprehensively and accurately.

Objective:To evaluate the calf muscle cross-sectional area (CSA) and fat fraction (FF) in amateur marathon runners based on T 2WI-Flex fat-suppression sequence and iterative decomposition of water and fat with echo asymmetrical and least-squares estimation quantitation sequence (IDEAL-IQ) technique, and to explore the correlation between them and age, body mass index (BMI), running age, speed exercise, and monthly exercise. Methods:From September to November 2022, 37 amateur marathon group (marathon group) and 12 healthy volunteers (control group) who did not often exercise were recruited in Shijiazhuang. T 2WI-Flex fat-suppression sequence and IDEAL-IQ sequence were performed on all subjects. The anterior group of the right calf (tibialis anterior, extensor hallucis longus, extensor digital longus), external group of the calf (peroneus longus, peroneus brevis), soleus, medial head and lateral head of the gastrocnemius were delineated along the edge of the muscle contour as regions of interest, and the CSA and FF values of the muscles were obtained. Twelve subjects matched with the clinical data of the control group were selected from the marathon group (marathon matched group), and the differences in CSA and FF were compared by independent sample t test or Mann-Whitney U test. Spearman correlation analysis was used to evaluate the correlation between CSA and FF values of the right calf and running-related indicators including age, BMI, running age, speed exercise, and monthly exercise in 37 amateur marathon runners. Results:The CSA of the right calf soleus muscle in the marathon matched matched group was larger than that in the control group ( t=-2.09, P=0.048). There was no significant difference in CSA of other calf muscles between the two groups ( P>0.05). The FF values of the right calf anterior group, the outer group, the soleus muscle, the medial head and the lateral head of the gastrocnemius muscle in the marathon matched group were lower than those in the control group ( P<0.05). The BMI of 37 amateur marathon runners was positively correlated with the CSA and FF values of the anterior group, the outer group, the soleus, the medial head and the lateral head of the gastrocnemius muscle (CSA: r=0.628, 0.468, 0.680, 0.566, 0.615, respectively, all P<0.05; FF value: r=0.395, 0.567, 0.631, 0.482, 0.516, respectively, all P<0.05). The FF values of the anterior group, the outer group, the soleus, the medial head and the lateral head of the gastrocnemius muscle were negatively correlated with monthly exercise ( r=-0.337, -0.405, -0.437, -0.338, -0.446, respectively, all P<0.05). Conclusions:Long-term running training can reduce the FF value of each calf muscle group, and the FF value of calf muscles is negatively correlated with the amount of running each month. Long-term running training has the greatest effect on the CSA of soleus muscle.

【Objective】 To explore the influencing factors of adolescent runaway and its correlation with family health so as to provide epidemiological evidence for future comprehensive interventions. 【Methods】 Using the quota sampling method, 1 065 adolescents aged 12-18 years old were surveyed by Questionnaire Star in 120 cities in China from July to September 2021. A well-developed electronic questionnaire was used to collect information about demographic characteristics, psychological characteristics, family health, social support, and behavior of running away from home. Univariate analysis and Logistic regression were used to explore the influencing factors of adolescent runaway and its correlation with family health. 【Results】 A total of 1 065 adolescents were investigated, among whom 334 were the only children (31.36%) and 442 were boys (41.50%). Univariate analysis revealed that 7.6% of teenagers had the experience of running away from home in the last 30 days. Participants who were ethnic minorities (P=0.031) and had education of technical school or junior college (P=0.029) and a low family income (P<0.001) were more likely to have running away behavior. Adolescents with low self-efficacy (P=0.005), depression (P<0.001), anxiety (P<0.001), and more stress had higher detection rates of runaway behavior. However, adolescents with higher family health and social support were less likely to run away from home (P<0.01). Multivariate analysis showed that compared with adolescents with low family health, adolescents with high (OR=0.16, 95% CI: 0.06-0.46) and moderate (OR=0.27, 95% CI: 0.14-0.55) family health had a significantly lower risk of runaway behavior. 【Conclusion】 The family is of great significance in preventing teenagers from running away from home. Parents should build a good parent-child relationship and create a happy family atmosphere to reduce the occurrence of teenagers running away from home.

【Objective】 To explore the effects of perceived risk of COVID-19 of college students on their anxiety and depression, as well as the roles of attention to negative information and perceived social support, so as to provide theoretical basis for colleges and universities to formulate corresponding intervention measures. 【Methods】 By the convenience sampling method, totally 1 404 college students from Shaanxi and Henan provinces were investigated online by using General Information Questionnaire, Perceived Risk of COVID-19 Pandemic Scale, Attention to Negative Information Scale, Patient Health Questionnaire, Generalized Anxiety Disorder and Perceived Social Support Scale. SPSS 20.0 was used for data analysis, Pearson correlation method was used to explore the correlation between variables. The mediating effect of attention to negative information and the moderating effect of perceived social support were analyzed by PROCESS. 【Results】 The scores of anxiety and depression of the 1 404 college students included in the study were 4.03±4.48 and 6.21±5.41, respectively. The detection rate of anxiety symptom was 29.9%, and that of depression symptom was 44.4%. The risk perception of COVID-19 epidemic of the college students was positively correlated with attention to negative information (r=0.373, P<0.001), anxiety (r=0.227, P<0.001), and depression (r=0.226, P<0.001). Anxiety (r=0.553, P<0.001) and depression (r=0.497, P<0.001) were positively correlated with attention to negative information, while perceived social support was negatively correlated with the risk perception of the COVID-19 (r=-0.154, P<0.001), attention to negative information (r=-0.259, P<0.001), anxiety (r=-0.321, P<0.001) and depression (r=-0.278, P<0.001). The risk perception of COVID-19 affected the anxiety and depression of the students mainly through the mediating effect of attention to negative information. The total effect of risk perception of COVID-19 and anxiety was 0.227, and the mediating effect accounted for 80.18% of the total effect. The total effect of risk perception of COVID-19 and depression was 0.228, and the mediating effect accounted for 90.35% of the total effect. Perceived social support played a moderating role in the last half of this mediating model. 【Conclusion】 Risk perception of COVID-19 indirectly affects the occurrence of anxiety and depression in college students through attention to negative information, and perceived social support plays a moderating role in this mediating model. The findings suggest that when a risk event occurs, colleges and universities should pay attention to guiding students to adjust their attentional bias to external information, and give students enough care and support to improve their mental health.

【Objective】 To explore the relationship between chronic comorbidity and the physical and mental health of relatives of elderly people during the nursing home confinement, and to analyze the mediating effects of perceived stress and intolerance of uncertainty in this context. 【Methods】 A total of 568 family members of elderly people in nine elderly institutions in Shaanxi Province were selected. The survey included the short version of the Perceived Stress Scale, Intolerance of Uncertainty Scale, and The World Health Organization-5 Well-being Index. The data were analyzed with Stata for correlation and mediation effects. 【Results】 ① The comorbidities of chronic diseases was positively correlated with the perceived stress (r=0.16, P<0.001) and intolerance of uncertainty (r=0.11, P=0.006) of the family members, but negatively correlated with the physical and mental health of the family members (r=-0.13, P=0.002). ② The mediating effect of perceived stress between chronic disease co-morbidity and physical and mental health of family members in older adults was -0.023, accounting for 18.8% of the total effect; the mediating effect of intolerance of uncertainty between chronic disease co-morbidity and physical and mental health of family members in older adults was -0.041, accounting for 33.5% of the total effect. 【Conclusion】 During closed management in a nursing facility, the physical and mental health of family members of older adults with chronic co-morbidities is poorer than that of family members of non-chronic co-morbidities. And it can lead to a decline in physical and mental health of family members through increased perceived stress and intolerance of uncertainty.