ABSTRACT
Objective@#To determine the relationship between mental sub-health and dietary behavior among Chinese adolescents, and to provide a scientific basis for improving adolescent mental sub-health through healthy dietary behavior.@*Methods@#A total of 16 545 adolescents aged 13 to 22 years were sampled by random cluster sampling method in six administrative regions of China. A questionnaire survey was conducted to investigate adolescents’ dietary behaviors and mental sub-health status.@*Results@#The proportion of boys consuming breakfast, snacks, carbonated drinks, vegetables, fish and dairy products was 76.2%, 20.2%, 19.0%, 78.4%, 52.4% and 59.2%, respectively, while the proportion of girls was 79.2%, 28.6%, 12.6%, 78.3%, 43.2% and 54.9%, respectively. Except for the "vegetable" option, dietary behaviors showed significant sex differences(χ2=20.79,320.10,229.06,150.27,32.21,P<0.01). In terms of mental sub-health, the detection rates of male adolescents’ mental sub-health status, behavioral sub-health and social sub-health were 20.7%, 26.0% and 17.2%, respectively, while those of female adolescents were 18.6%, 24.1% and 14.8%, respectively. The differences between boys and girls were statistically significant (χ2=17.32,7.66,17.46,P<0.01). Controlling for age and gender, breakfast "normally eating" and "occasionally eat", vegetables "normally eating" and "occasionally eat", fish "normally eating" and "occasionally eat", milk, dairy products "normally drink" and "occasional drink",was negatively associated with teenagers’ psychological sub-health (OR=0.60,0.73;0.50,0.65;0.74,0.77;0.73,0.69,P<0.05).@*Conclusion@#Healthy dietary behavior could be protective to avoid adolescent mental sub-health.Nutritional lectures and guideline books are needed among students and their parents.Nutritionists are encouraged to provide healthy nutritional advice to school canteen.
ABSTRACT
OBJECTIVE:To compare the performance of several pattern recognition methods in the identification of volatile oils of traditional Chinese medicine(TCM)by infrared spectroscopy. METHODS:The volatile oils of several Lonicera and Citrus TCM were determined by infrared spectroscopy. All samples of infrared spectrum were classified by hierarchical clustering,K-mean clustering,artificial neural networks,and support vector machine. RESULTS:The results of hierarchical clustering and K-mean clus-tering were ineffective. Methods of artificial neural networks and support vector machine achieved correct classification rate of 100%. CONCLUSIONS:Artificial neural networks and support vector machine can be combined with infrared spectroscopy to cre-ate chemometric fingerprinting for the identification of volatile oils of TCM.
ABSTRACT
Objective To set up a method for identification of Lonicerae japonicae flos volatile oils using Fourier-transform infrared spectroscopy. Methods The volatile oils of Lonicerae japonicae flos and Lonicerae flos was extracted by steam distillation combined with continuous liquid-liquid extraction with hexane. An oil film was prepared for Fourier-transform infrared spectroscopy scanning by dropping the volatile oils solution on the KBr disc and evaporating the solvent. The obtained infrared spectrum was treated by baseline removing and median filter smoothing. The spectral data within 1800-850 cm-1 was selected as the characteristic spectrum for hierarchical cluster analysis. And the volatile oils of Lonicerae japonicae flos and Lonicerae flos were discriminated by the result of hierarchical cluster analysis. Results Enough volatile oils were extracted for obtaining Fourier-transform infrared spectrum from small amount of Lonicerae japonicae flos. The method developed in the study was able to discriminate Lonicerae japonicae flos volatile oils from Lonicerae flos volatile oils. Conclusion The method can be used for identification of Lonicerae japonicae flos volatile oils.