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The interaction between biological surfactant sodium deoxycholate (NaDC) and nonionic surfactants polyoxyethylene (n) nonylphenol ether (NPn) for the formation of micelles in aqueous solution were investigated. Surface tension, interfacial dilational viscoelasticity, and transmission electron microscopy (TEM) were characterized to systematically study the interaction between NaDC and NPn in buffer solution. At last, the mechanism of the interaction between NPn and NaDC were analyzed. The surface tension results show that the interaction between NaDC and NPn was displayed synergism action. The composition of the mixed systems has been estimated on account of the regular solution theory, Clint's equation, Rubingh theory and Rosen theory. The surface dilational rheology provided abundant effective information on the feature of adsorbed layers. From the oscillating barrier measurements, the peak values of the dilational modulus moved to lower concentrations in NaDC/NPn binary system compared to single surfactant. The dilational elasticity of the binary system decreased distinctly on the basis of the rigid structure of NaDC. The interaction of these two substances was proved directly by TEM images, that the boundaries of the aggregates are clearer due to the protection of NPn molecules. The new complex systems have potential application in environmental protection. Schematic illustration of the aggregation in NPn/NaDC mixed systems and concentration increased from left to right. [ABSTRACT FROM AUTHOR]

We sought to validate the Dutch Eating Behavior Questionnaire (DEBQ) in a sample of Chinese adolescents and investigate differences in eating behaviors among Chinese normal weight, overweight, and obese adolescents. Chinese middle and high school students completed the DEBQ, Eating Disorder Inventory-1, and the Self-Control Scale. Result showed that the DEBQ had good internal consistency, test–retest reliability and criterion validity. Furthermore, the obese and overweight adolescents scored significantly higher than normal weight adolescents on three subscales. The DEBQ is effective for assessing eating behaviors in Chinese adolescents. [ABSTRACT FROM PUBLISHER]