The aim of this study was to investigate the chemical compositions of chalk dust and examine the adverse effects of fine chalk particle matters（PM（2.5）） on rat alveolar macrophages（AMs） in vitro.Morphologies and...The aim of this study was to investigate the chemical compositions of chalk dust and examine the adverse effects of fine chalk particle matters（PM（2.5）） on rat alveolar macrophages（AMs） in vitro.Morphologies and element concentrations of chalk particles were analyzed using quantitative energydispersive electron probe X-ray microanalysis（ED-EPMA）.The oxidative response of AMs exposed to chalk PM（2.5） was measured by luminol-dependent chemiluminescence（CL）.The results showed that（1）Chalk dust was mainly composed of gypsum（CaSO4）,calcite（CaCO3）/dolomite（CaMg（CO3）2）,and organic adhesives;（2） Fine chalk particles induced the AM production of CL,which was inhibited by about 90%by diphenyleneiodonium chloride（DPI）.Based on these results,we showed that cytotoxicity of chalk PM（2.5） may be related to the reactive oxygen species（ROS） generation.展开更多
This study presents new thickness maps of post-Cretaceous sedimentary strata beneath central London. 〉1100 borehole records were analysed. London Clay is thickest in the west; thicker deposits extend as a narrow fing...This study presents new thickness maps of post-Cretaceous sedimentary strata beneath central London. 〉1100 borehole records were analysed. London Clay is thickest in the west; thicker deposits extend as a narrow finger along the axis of the London Basin. More minor variations are probably governed by periglacial erosion and faulting. A shallow anticline in the Chalk in north-central London has resulted in a pronounced thinning of succeeding strata. These results are compared to the position of London Underground railway tunnels. Although tunnels have been bored through the upper levels of London Clay where thick, some tunnels and stations are positioned within the underlying, more lithologically variable, Lower London Tertiary deposits. Although less complex than other geological models of the London Basin, this technique is more objective and uses a higher density of borehole data. The high resolution of the resulting maps emphasises the power of modelling an expansive dataset in a rigorous but simnle fashion.展开更多
基金supported by grants from the National Natural Science Foundation of China(Nos.21107064,2140509,21175086 and 21177078)by grant from Shanxi Scholarship Council of China(Nos.2013-012 and 2013-016)
文摘The aim of this study was to investigate the chemical compositions of chalk dust and examine the adverse effects of fine chalk particle matters（PM（2.5）） on rat alveolar macrophages（AMs） in vitro.Morphologies and element concentrations of chalk particles were analyzed using quantitative energydispersive electron probe X-ray microanalysis（ED-EPMA）.The oxidative response of AMs exposed to chalk PM（2.5） was measured by luminol-dependent chemiluminescence（CL）.The results showed that（1）Chalk dust was mainly composed of gypsum（CaSO4）,calcite（CaCO3）/dolomite（CaMg（CO3）2）,and organic adhesives;（2） Fine chalk particles induced the AM production of CL,which was inhibited by about 90%by diphenyleneiodonium chloride（DPI）.Based on these results,we showed that cytotoxicity of chalk PM（2.5） may be related to the reactive oxygen species（ROS） generation.
文摘This study presents new thickness maps of post-Cretaceous sedimentary strata beneath central London. 〉1100 borehole records were analysed. London Clay is thickest in the west; thicker deposits extend as a narrow finger along the axis of the London Basin. More minor variations are probably governed by periglacial erosion and faulting. A shallow anticline in the Chalk in north-central London has resulted in a pronounced thinning of succeeding strata. These results are compared to the position of London Underground railway tunnels. Although tunnels have been bored through the upper levels of London Clay where thick, some tunnels and stations are positioned within the underlying, more lithologically variable, Lower London Tertiary deposits. Although less complex than other geological models of the London Basin, this technique is more objective and uses a higher density of borehole data. The high resolution of the resulting maps emphasises the power of modelling an expansive dataset in a rigorous but simnle fashion.
