目的通过小鼠梗黄及胆汁内外引流模型,观察小鼠肠黏膜胆汁酸核受体法尼酯衍生物X受体(Farnesoid X receptor,FXR)和病原模式识别受体Toll样受体4(Toll-like receptor 4,TLR4)的表达变化并探讨两者之间的相互作用。方法采用成年雄性昆明...目的通过小鼠梗黄及胆汁内外引流模型,观察小鼠肠黏膜胆汁酸核受体法尼酯衍生物X受体(Farnesoid X receptor,FXR)和病原模式识别受体Toll样受体4(Toll-like receptor 4,TLR4)的表达变化并探讨两者之间的相互作用。方法采用成年雄性昆明小鼠60只随机分为四组,即梗黄组(OJ组)、胆汁外引流组(ED组)、胆汁内引流组(ID组)和假手术组(SH组),每组15只。利用蛋白质印迹分析(Western blotting)和实时荧光定量PCR(qRT-PCR)法检测回肠黏膜FXR与TLR4蛋白及其mRNA的表达。此外,取40只小鼠随机分为OJ、ED、ID和SH四组,每组10只,各组中再用FXR激动剂GW4064(n=5)灌胃干预,羧甲基纤维素钠CMC-Na(n=5)作为对照。结果小鼠胆道梗阻后,肠黏膜FXR蛋白及其mRNA表达较SH组明显升高,肠黏膜TLR4蛋白及其mRNA表达较SH组明显下降。胆汁外引流术后,FXR蛋白表达较OJ组明显下降而其mRNA表达升高,TLR4蛋白及其mRNA表达明显升高。胆汁内引流术后,FXR蛋白及其mRNA表达较OJ组下降,TLR4蛋白及其mRNA表达明显上升,效果均好于外引流(P<0.05)。安慰剂灌胃和上述未行灌胃的小鼠的TLR4表达趋势基本一致,而利用FXR激动剂灌胃后,四组小鼠TLR4表达差异消失(P>0.05)。结论小鼠梗黄形成后,肠道FXR升高,TLR4下降,胆汁内引流和外引流均可逆转这些改变,但内引流效果好于外引流。肠道内胆汁酸是引起这些变化的关键。展开更多
Based on Guenther light-temperature model , annual emission of VOCs discharged by plants in Nanjing was estimated, and the impacts of VOCs discharged by afforesting vegetation in the city on ozone concentration was an...Based on Guenther light-temperature model , annual emission of VOCs discharged by plants in Nanjing was estimated, and the impacts of VOCs discharged by afforesting vegetation in the city on ozone concentration was analyzed. The results show that annual emission of VOCs dis- charged by plants in Nanjing is about 0.004 9 Tg C. The annual emmisions of isoprene, monoterpene and other VOCs account for 18.0%, 25.9% and 56.1% of total emission of VOCs respectively. VOCs discharged by afforesting vegetation in Nanjing has the greatest impact on average con- centration of ozone in winter.展开更多
Polymeric carbon nitride(PCN)has emerged as a promising candidate for photocatalytic hydrogen evolution,but its dependence on scarce and high-cost noble metal co-catalysts severely limits its extensive application.It ...Polymeric carbon nitride(PCN)has emerged as a promising candidate for photocatalytic hydrogen evolution,but its dependence on scarce and high-cost noble metal co-catalysts severely limits its extensive application.It will be of great promise to develop non-noble metal single-atom co-catalysts with low-cost and high atom utilization to improve the photocatalytic performance over PCN.Herein,single Ni atoms are successfully anchored onto carbon-vacant PCN nanosheets(CCN-SANi)via a two-step ammonia thermal treatment and photo-deposition process.Theoretical calculations and experimental results demonstrate that the optical absorption property and the charge transfer ability of CCN-SANi have been significantly improved with the introduction of single Ni atoms to form Ni-N3 sites.In comparison to carbon-vacant PCN(CCN)loaded with Ni clusters,the obtained CCN-SANi exhibits 11.4 times increased photocatalytic performance,with the highest hydrogen evolution rate reaching 511μmol/(g·h),which is even 1.7 times higher than that of CCN loaded with Pt clusters.This research proposes an inspiring and reliable strategy to design novel single-atom semiconducting polymers with electronic structures manipulated for efficient photocatalysis.展开更多
文摘Based on Guenther light-temperature model , annual emission of VOCs discharged by plants in Nanjing was estimated, and the impacts of VOCs discharged by afforesting vegetation in the city on ozone concentration was analyzed. The results show that annual emission of VOCs dis- charged by plants in Nanjing is about 0.004 9 Tg C. The annual emmisions of isoprene, monoterpene and other VOCs account for 18.0%, 25.9% and 56.1% of total emission of VOCs respectively. VOCs discharged by afforesting vegetation in Nanjing has the greatest impact on average con- centration of ozone in winter.
基金National Key Research and Development Program of China(No.2018YFB1502003)National Natural Science Foundation of China(No.21875183)+1 种基金Natural Science Basic Research Program of Shaanxi Province,China(No.2019JCW-10)Fundamental Research Funds for the Central Universities,China and the Youth Innovation Team of Shaanxi Universities,China.
文摘Polymeric carbon nitride(PCN)has emerged as a promising candidate for photocatalytic hydrogen evolution,but its dependence on scarce and high-cost noble metal co-catalysts severely limits its extensive application.It will be of great promise to develop non-noble metal single-atom co-catalysts with low-cost and high atom utilization to improve the photocatalytic performance over PCN.Herein,single Ni atoms are successfully anchored onto carbon-vacant PCN nanosheets(CCN-SANi)via a two-step ammonia thermal treatment and photo-deposition process.Theoretical calculations and experimental results demonstrate that the optical absorption property and the charge transfer ability of CCN-SANi have been significantly improved with the introduction of single Ni atoms to form Ni-N3 sites.In comparison to carbon-vacant PCN(CCN)loaded with Ni clusters,the obtained CCN-SANi exhibits 11.4 times increased photocatalytic performance,with the highest hydrogen evolution rate reaching 511μmol/(g·h),which is even 1.7 times higher than that of CCN loaded with Pt clusters.This research proposes an inspiring and reliable strategy to design novel single-atom semiconducting polymers with electronic structures manipulated for efficient photocatalysis.
