Effective biomarkers are necessary to better understand the human mercury(Hg) exposure levels. However, mismatched biomarker sampling method causes extra uncertainty in assessing the risk of Hg exposure. To compare th...Effective biomarkers are necessary to better understand the human mercury(Hg) exposure levels. However, mismatched biomarker sampling method causes extra uncertainty in assessing the risk of Hg exposure. To compare the differences between hair and fingernail, and further understand the excretion rates of methylmercury(MeHg) and inorganic mercury(IHg) via hair and fingernails, the total mercury(THg), Me Hg, and IHg concentrations in paired hair and fingernail samples were investigated through paired samples collected from two typical mining areas, Wanshan mercury mine area(WMMA) and Hezhang zinc smelting area(HZSA). The positive correlation in THg, MeHg, and IHg concentrations( p < 0.01) between hair and fingernail samples indicated that those two biomarkers can be corrected in application of assessing human Hg exposure. Compared to fingernails, the hair was suggested to be a more sensitive biomarker as the concentration of THg, MeHg and IHg were 2~4 times higher than those in fingernails. Furthermore, the amounts of THg, MeHg, and IHg excreted via hair were 70~226 times higher than that excreted via fingernails, and the hair plays a more important role than fingernails in the excretion of Hg from human bodies. Present study therefore provides some new insights to better understand the fate of human assimilated Hg.展开更多
The rational integration of multi-functional components with metal–organic frameworks(MOFs) to form MOF-based catalysts can often afford enhanced catalytic activity for specific reactions. Herein, we propose a novel ...The rational integration of multi-functional components with metal–organic frameworks(MOFs) to form MOF-based catalysts can often afford enhanced catalytic activity for specific reactions. Herein, we propose a novel strategy for the synthesis of hierarchically porous MOFs(e.g., MIL-101)-encapsulated N-doped nanocarbon(CN@MIL) by controlled pyrolysis of ionic liquids@MIL-101 precursors(ILs@MIL). The obtained CN@MIL composites not only possess abundant enlarged mesopores,but also show multi-active sites without the sacrifice of their structure stability. The CN@MIL can efficiently facilitate the mass transfer of substrates, exhibiting excellent catalytic performance in the synthesis of cyclic carbonates from epoxides and CO_(2) under mild and co-catalyst-free conditions(i.e., 90 ℃ and ambient pressure of CO_(2)). Furthermore, the multi-active Lewis acid sites and nucleophilic sites(Br ions) as well as the strong affinity of catalysts toward CO_(2)also contribute to the excellent catalytic activity of the CN@MIL. This study might open a new avenue for the rational design of MOF-based composites by employing ILs@MOF as precursors for advanced heterogeneous catalysis.展开更多
基金funded by t he Strategic Priority Research Programs of the Chinese Academy of Sciences (Pan-TPE, XDA20040502 )the National Natural Science Foundation of China (Nos. 41877405 , U1612442 , U1812403 )。
文摘Effective biomarkers are necessary to better understand the human mercury(Hg) exposure levels. However, mismatched biomarker sampling method causes extra uncertainty in assessing the risk of Hg exposure. To compare the differences between hair and fingernail, and further understand the excretion rates of methylmercury(MeHg) and inorganic mercury(IHg) via hair and fingernails, the total mercury(THg), Me Hg, and IHg concentrations in paired hair and fingernail samples were investigated through paired samples collected from two typical mining areas, Wanshan mercury mine area(WMMA) and Hezhang zinc smelting area(HZSA). The positive correlation in THg, MeHg, and IHg concentrations( p < 0.01) between hair and fingernail samples indicated that those two biomarkers can be corrected in application of assessing human Hg exposure. Compared to fingernails, the hair was suggested to be a more sensitive biomarker as the concentration of THg, MeHg and IHg were 2~4 times higher than those in fingernails. Furthermore, the amounts of THg, MeHg, and IHg excreted via hair were 70~226 times higher than that excreted via fingernails, and the hair plays a more important role than fingernails in the excretion of Hg from human bodies. Present study therefore provides some new insights to better understand the fate of human assimilated Hg.
基金financially supported by the National Natural Science Foundation of China (21825802, 22138003)the Natural Science Foundation of Guangdong Province (2017A030312005)+1 种基金the Guangdong Natural Science Funds for Distinguished Young Scholar (2018B030306050)the Science and Technology Program of Qingyuan City (2021YFJH01002)。
文摘The rational integration of multi-functional components with metal–organic frameworks(MOFs) to form MOF-based catalysts can often afford enhanced catalytic activity for specific reactions. Herein, we propose a novel strategy for the synthesis of hierarchically porous MOFs(e.g., MIL-101)-encapsulated N-doped nanocarbon(CN@MIL) by controlled pyrolysis of ionic liquids@MIL-101 precursors(ILs@MIL). The obtained CN@MIL composites not only possess abundant enlarged mesopores,but also show multi-active sites without the sacrifice of their structure stability. The CN@MIL can efficiently facilitate the mass transfer of substrates, exhibiting excellent catalytic performance in the synthesis of cyclic carbonates from epoxides and CO_(2) under mild and co-catalyst-free conditions(i.e., 90 ℃ and ambient pressure of CO_(2)). Furthermore, the multi-active Lewis acid sites and nucleophilic sites(Br ions) as well as the strong affinity of catalysts toward CO_(2)also contribute to the excellent catalytic activity of the CN@MIL. This study might open a new avenue for the rational design of MOF-based composites by employing ILs@MOF as precursors for advanced heterogeneous catalysis.
