日韩av大片在线观看欧美成人不卡|午夜先锋看片|中国女人18毛片水多|免费xx高潮喷水|国产大片美女av|丰满老熟妇好大bbbbbbbbbbb|人妻上司四区|japanese人妻少妇乱中文|少妇做爰喷水高潮受不了|美女人妻被颜射的视频,亚洲国产精品久久艾草一,俄罗斯6一一11萝裸体自慰,午夜三级理论在线观看无码

 

文獻(xiàn)名：Influences of a standardized food matrix and gastrointestinal fluids on the physicochemical properties of titanium dioxide nanoparticles

 

 

作者： Yan Li, Kun Jiang, Hui Cao, Min Yuan and Fei Xu
School of Medical Instrument and Food Engineering, Shanghai Engineering Research Center for Food Rapid Detection, University of Shanghai for Science and Technology, Shanghai 200093, China.

 

 

摘要：The fast-growing applications of engineered titanium dioxide nanoparticles (e-TiO₂-NPs) in the food and pharmaceutical industry in production, packaging, sensors, nutrient delivery systems, and food additives enhance the possibility of oral exposure. Physicochemical transformations may occur when e-TiO₂-NPs are incorporated into a food matrix and pass through the human gastrointestinal tract (GIT), which may redefine the toxic effects of the e-TiO₂-NPs. In this study, a standardized food model (SFM) and simulated gastrointestinal fluids have been used to study the fate of e-TiO₂-NPs following a three-step digestion model in vitro, and a case study was carried out to assess the toxicity of the digested e-TiO₂-NPs using an in vitro cellular model. In the absence and presence of the SFM, the transformations of the tristimulus color coordinates, size, agglomeration state, surface charge and solubility of the e-TiO₂-NPs in the salivary, gastric and intestinal digestion fluids were compared with those before digestion. The results demonstrate that the presence of the SFM impacted the physicochemical properties of the e-TiO₂-NPs significantly. The SFM stabilized the e-TiO₂-NP suspensions and acted as a dispersant during each digestive phase. The e-TiO₂-NPs showed differentiated transformations of their physicochemical properties after each step of the digestive process. The pH shifts and variable concentrations of enzymes and salts in gastrointestinal fluids induced the transformations of the physicochemical properties of the e-TiO₂-NPs. The transformed e-TiO₂-NPs could release titanium ion in the gastrointestinal tract. Also, the cell viability induced by e-TiO₂-NPs was found to be strongly affected by the presence of the SFM and simulated human GIT fluids. It can be concluded that the physicochemical transformations of the e-TiO₂-NPs that were found when they were incorporated into an SFM and passed through the GIT consequently strongly affected the biological effects of the e-TiO₂-NPs, which highlights that the toxicity assessment of ingested NPs should use appropriate standardized food models and take realistic physiological conditions into account.

 

關(guān)鍵詞：