Origin identification of Polygonatum cyrtonema based on hyperspectral data / 中国中药杂志

In this study, visual-near infrared(VNIR), short-wave infrared(SWIR), and VNIR + SWIR fusion hyperspectral data of Polygonatum cyrtonema from different geographical origins were collected and preprocessed by first derivative(FD), second derivative(SD), Savitzky-Golay smoothing(S-G), standard normalized variate(SNV), multiplicative scatter correction(MSC), FD+S-G, and SD+S-G. Three algorithms, namely random forest(RF), linear support vector classification(LinearSVC), and partial least squares discriminant analysis(PLS-DA), were used to establish the identification models of P. cyrtonema origin from three spatial scales, i.e., province, county, and township, respectively. Successive projection algorithm(SPA) and competitive adaptive reweighted sampling(CARS) were used to screen the characteristic bands, and the P. cyrtonema origin identification models were established according to the selected characteristic bands. The results showed that(1)after FD preprocessing of VNIR+SWIR fusion hyperspectral data, the accuracy of recognition models established using LinearSVC was the highest, reaching 99.97% and 99.82% in the province origin identification model, 100.00% and 99.46% in the county origin identification model, and 99.62% and 98.39% in the township origin identification model. The accuracy of province, county, and township origin identification models reached more than 98.00%.(2)Among the 26 characteristic bands selected by CARS, after FD pretreatment, the accuracy of origin identification models of different spatial scales was the highest using LinearSVC, reaching 98.59% and 97.05% in the province origin identification model, 97.79% and 94.75% in the county origin identification model, and 90.13% and 87.95% in the township origin identification model. The accuracy of identification models of different spatial scales established by 26 characteristic bands reached more than 87.00%. The results show that hyperspectral imaging technology can realize accurate identification of P. cyrtonema origin from different spatial scales.

Origin identification of Poria cocos based on hyperspectral imaging technology / 中国中药杂志

To realize the non-destructive and rapid origin discrimination of Poria cocos in batches, this study established the P. cocos origin recognition model based on hyperspectral imaging combined with machine learning. P. cocos samples from Anhui, Fujian, Guangxi, Hubei, Hunan, Henan and Yunnan were used as the research objects. Hyperspectral data were collected in the visible and near infrared band(V-band, 410-990 nm) and shortwave infrared band(S-band, 950-2 500 nm). The original spectral data were divided into S-band, V-band and full-band. With the original data(RD) of different bands, multiplicative scatter correction(MSC), standard normal variation(SNV), S-G smoothing(SGS), first derivative(FD), second derivative(SD) and other pretreatments were carried out. Then the data were classified according to three different types of producing areas: province, county and batch. The origin identification model was established by partial least squares discriminant analysis(PLS-DA) and linear support vector machine(LinearSVC). Finally, confusion matrix was employed to evaluate the optimal model, with F1 score as the evaluation standard. The results revealed that the origin identification model established by FD combined with LinearSVC had the highest prediction accuracy in full-band range classified by province, V-band range by county and full-band range by batch, which were 99.28%, 98.55% and 97.45%, respectively, and the overall F1 scores of these three models were 99.16%, 98.59% and 97.58%, respectively, indicating excellent performance of these models. Therefore, hyperspectral imaging combined with LinearSVC can realize the non-destructive, accurate and rapid identification of P. cocos from different producing areas in batches, which is conducive to the directional research and production of P. cocos.

Research progress on influencing factors of depressive symptoms in adolescents / 中国学校卫生

Abstract@#In recent years, mental health problems such as anxiety and depression among adolescents in China have attracted attention from all walks of life. Given that adolescence is a transitional and critical period for individual development, mental health affect the developmental opportunities. Therefore, in the review, the effects of environment, psychosocial factors and behavioral patterns on depressive symptoms are analyzed by combining with the characteristics of physical and mental development among adolescents. It is found that early adolescence and even childhood should be the key period for the prevention and intervention of depression. In order to formulate effective interventions and prevention strategies, it is proposed that future research should combine real situation in China with active exploration of protective factors and early predictors of depression.

Physical activity of Chinese children and adolescents:age, gender and regional characteristics / 中国学校卫生

Objective@#To explore age, gender, and regional differences in physical activity among children and adolescents in China, and to provide a scientific reference for enhancing physical activity promotion.@*Methods@#A total of 4 269 children and adolescents aged 7 to 18 years were selected from six administrative regions of China (East China, Northwest China, North China, Central China, Southwest China and South China) using a stratified random cluster sampling method from September to December 2018. A questionnaire was administered to evaluate the physical activity level of Chinese children and adolescents aged 7 to 18.@*Results@#The overall detection rate of MVPA insufficiency in children and adolescents in China was 53.8%, of which the detection rate of MVPA insufficiency was 50.8% among boys and 57.1% among girls. Gender differences were statistically significant ( χ 2= 17.10 , P <0.05). Among the different age groups, the lowest detection rate of MVPA among 10-12 year olds was 43.6%, whereas the highest rate among 16-18 year olds was 63.0%, with significant differences between gender ( χ 2=4.33, 30.79, P <0.05). The P 50 values of total physical activity(TPA), light intensity physical activity(LPA), moderate intensity physical activity(MPA), vigorous intensity physical activity(VPA), moderate to vigorous physical activity(MVPA) were 92.9,24.3,41.4,7.1 and 55.7 min/d , respectively. The P 50 values of physical exercise, housework activities, entertainment activities and transportation activities were 34.3 , 2.1, 2.3 and 30.0 min/d, respectively, and the difference in age groups was statistically significant( H =95.03, 74.99, 300.26 , 64.16, P <0.05). There was a statistically significant difference in the detection rate of insufficient MVPA among children and adolescents in different regions ( χ 2=83.91, P <0.05). The lowest rate was 44.0% in North China, and the highest was 65.9% in East China.@*Conclusion@#The detection rate of MVPA insufficiency among Chinese children and adolescents firstly decreased and then increased with age. Boys participated in higher levels of physical activity than girls.