The most recent in vitro tests used to determine metal bioaccessiblility are generally time-consuming and expensive. This study aimed at determining potential relationships between the concentrations of metals extract...The most recent in vitro tests used to determine metal bioaccessiblility are generally time-consuming and expensive. This study aimed at determining potential relationships between the concentrations of metals extracted using single-extraction methods and the concentrations of bioaccessible metals assessed by a harmonised in vitro test, the Unified BARGE Method （UBM）. A total number of 27 soil samples were collected from kitchen gardens and lawns with various physicochemical parameters and contamination levels. Significant relationships were obtained between Cd, Pb and Zn extracted in gastric and gastrointestinal phases and using single extractions. The best relationhips were established using acetic and citric acids for Cd, whereas for Pb, citric acid and ethylenedi- aminetetraacetic acid （EDTA） were identified as the best extractants. These relationships were improved by means of a linear multiple regression with a downward stepwise procedure involving agronomic parameters （soil cation exchange capacity and assimilated P）. This method highlighted the fact that the cation exchange capacity and P contents in soils were the two main parameters that controlled the human bioaccessibility of Cd, Pb and Zn in the gastric phase. Besides, the metal concentrations extracted with the acetic and citric acids correlated well with the metal concentrations in the gastric and gastrointestinal phases, suggesting that the bioaceessible metals were mainly in a soluble form, weakly bound to the organic matter and associated with the carbonates and the Fe and Mn oxides/hydroxides in soils.展开更多
Graphene has lots of applications, such as field-effect transistors, solar cells and transparent electrodes. In this work, we developed a new donor-acceptor graphene hybrid by covalently bonding a donor phenanthrene-9...Graphene has lots of applications, such as field-effect transistors, solar cells and transparent electrodes. In this work, we developed a new donor-acceptor graphene hybrid by covalently bonding a donor phenanthrene-9-carboxaldehyde (PCA) onto the acceptor graphene (PCA-graphene) via 1,3-dipolar cycloaddition azomethine ylides. The resulting PCA-graphene is soluble in N,N-dimethyformamide (DMF). The optoelectronic device (photoanode) fabricated by spin-coating DMF solution of the hybrids exhibits an enhanced photocurrent under visible irradiation.展开更多
基金the Nord-Pas de Calais Council and Agence de l’Environnement et de la Matrise de l’Energie (ADEME), France, for the financial support of this research
文摘The most recent in vitro tests used to determine metal bioaccessiblility are generally time-consuming and expensive. This study aimed at determining potential relationships between the concentrations of metals extracted using single-extraction methods and the concentrations of bioaccessible metals assessed by a harmonised in vitro test, the Unified BARGE Method （UBM）. A total number of 27 soil samples were collected from kitchen gardens and lawns with various physicochemical parameters and contamination levels. Significant relationships were obtained between Cd, Pb and Zn extracted in gastric and gastrointestinal phases and using single extractions. The best relationhips were established using acetic and citric acids for Cd, whereas for Pb, citric acid and ethylenedi- aminetetraacetic acid （EDTA） were identified as the best extractants. These relationships were improved by means of a linear multiple regression with a downward stepwise procedure involving agronomic parameters （soil cation exchange capacity and assimilated P）. This method highlighted the fact that the cation exchange capacity and P contents in soils were the two main parameters that controlled the human bioaccessibility of Cd, Pb and Zn in the gastric phase. Besides, the metal concentrations extracted with the acetic and citric acids correlated well with the metal concentrations in the gastric and gastrointestinal phases, suggesting that the bioaceessible metals were mainly in a soluble form, weakly bound to the organic matter and associated with the carbonates and the Fe and Mn oxides/hydroxides in soils.
基金supported by the National Natural Science Foundation of China (20920102034, 20877076 & 20907056)the National Basic Research Program of China (2010CB933503 & 2007CB613306)
文摘Graphene has lots of applications, such as field-effect transistors, solar cells and transparent electrodes. In this work, we developed a new donor-acceptor graphene hybrid by covalently bonding a donor phenanthrene-9-carboxaldehyde (PCA) onto the acceptor graphene (PCA-graphene) via 1,3-dipolar cycloaddition azomethine ylides. The resulting PCA-graphene is soluble in N,N-dimethyformamide (DMF). The optoelectronic device (photoanode) fabricated by spin-coating DMF solution of the hybrids exhibits an enhanced photocurrent under visible irradiation.
