The coupling reactions of simple methyl ketones with o-bromoacetophenones and subsquential cyclization reactions were realized to produce a range of 1-naphthols. These cascade reactions were initiated by a rare Cu-cat...The coupling reactions of simple methyl ketones with o-bromoacetophenones and subsquential cyclization reactions were realized to produce a range of 1-naphthols. These cascade reactions were initiated by a rare Cu-catalyzed arylation reaction of methyl ketones with aromatic bromides.展开更多
Background：PM2.5 （aerodynamic diameter ≤ 2.5 μtm） is a dominant and ubiquitous air pollutant that has become a global concern as PM2.5 exposure has been linked to many adverse health effects including cardiovascu...Background：PM2.5 （aerodynamic diameter ≤ 2.5 μtm） is a dominant and ubiquitous air pollutant that has become a global concern as PM2.5 exposure has been linked to many adverse health effects including cardiovascular and pulmonary diseases.Emerging evidence supports a correlation between increased air PM2.5 levels and skin disorders although reports on the underlying pathophysiological mechanisms are limited.Oxidative stress is the most common mechanism of PM2.5-induced adverse health effects.This study aimed to investigate PM2.5-induced oxidative damage and apoptosis in immortalized human keratinocyte （HaCaT） cells.Methods：HaCaT cells were exposed to 0,25,50,100,or 200 μtg/ml PM2.5 for 24 h.Reactive oxygen species （ROS） generation,lipid peroxidation products,antioxidant activity,DNA damage,apoptotic protein expression,and cell apoptosis were measured.Results：PM2.5 exposure （0-200 μtg/ml） for 24 h resulted in increased ROS levels （arbitrary unit：201.00 ± 19.28,264.50 ± 17.91,305.05 ± 19.57,427.95 ＋ 18.32,and 436.70 ± 17.77） and malondialdehyde production （0.54 ± 0.05 nmol/mg prot,0.61 ± 0.06 nmol/mg prot,0.68 ± 0.05 nmol/mg prot,0.70 ± 0.05 nmol/mg prot,and 0.76 ± 0.05 nmol/mg prot）,diminished superoxide dismutase activity （6.47 ± 0.28 NU/mg prot,5.97 ± 0.30 NU/mg prot,5.15 ± 0.42 NU/mg prot,4.08 ± 0.20 NU/mg prot,and 3.76 ± 0.37 NU/mg prot）,and increased DNA damage and apoptosis in a dose-dependent manner in HaCaT cells.Moreover,cytochrome-c,caspase-3,and caspase-9 expression also increased proportionately with PM2.5 dosing.Conclusion：PM2.5 might elicit oxidative stress and mitochondria-dependent apoptosis that likely manifests as skin irritation and damage.展开更多
A straightforward electrochemical reduction of benzo[b]thiophene 1,1-dioxides with HFIP as the hydrogen donor has been reported in an undivided cell under metal-free conditions.Moreover,the tolerance of various functi...A straightforward electrochemical reduction of benzo[b]thiophene 1,1-dioxides with HFIP as the hydrogen donor has been reported in an undivided cell under metal-free conditions.Moreover,the tolerance of various functional groups and scaled-up experiments showed the practicability and potential applications of this methodology.展开更多
Main observation and conclusion A general and practical protocol for the construction of diversified sulfur heterocycles has been described through organic electrosynthesis means.In undivided cell,dihydrothiophenes,th...Main observation and conclusion A general and practical protocol for the construction of diversified sulfur heterocycles has been described through organic electrosynthesis means.In undivided cell,dihydrothiophenes,thiazolines and 1,4-dithiines could be easily generated from various availableβ-ketothioamides under metal-free and external oxidant-free conditions.展开更多
Main observation and conclusion Through the intramolecular cyclization of N-methoxybenzamides,a simple and efficient method for constructing valuable isoindolinones under metal-free conditions was developed.The reacti...Main observation and conclusion Through the intramolecular cyclization of N-methoxybenzamides,a simple and efficient method for constructing valuable isoindolinones under metal-free conditions was developed.The reaction was featured by employing low-cost catalyst,simple operation,100%atomic economy and excellent regioselectivity.Moreover,a detailed computational study on the reaction system has been performed to clarify the mechanism.展开更多
基金supported by National Natural Science Foundation of China (Nos. 21102080, 21372138)Tsinghua University Initiative Scientific Research Program (No. 2011Z02150)
文摘The coupling reactions of simple methyl ketones with o-bromoacetophenones and subsquential cyclization reactions were realized to produce a range of 1-naphthols. These cascade reactions were initiated by a rare Cu-catalyzed arylation reaction of methyl ketones with aromatic bromides.
文摘Background：PM2.5 （aerodynamic diameter ≤ 2.5 μtm） is a dominant and ubiquitous air pollutant that has become a global concern as PM2.5 exposure has been linked to many adverse health effects including cardiovascular and pulmonary diseases.Emerging evidence supports a correlation between increased air PM2.5 levels and skin disorders although reports on the underlying pathophysiological mechanisms are limited.Oxidative stress is the most common mechanism of PM2.5-induced adverse health effects.This study aimed to investigate PM2.5-induced oxidative damage and apoptosis in immortalized human keratinocyte （HaCaT） cells.Methods：HaCaT cells were exposed to 0,25,50,100,or 200 μtg/ml PM2.5 for 24 h.Reactive oxygen species （ROS） generation,lipid peroxidation products,antioxidant activity,DNA damage,apoptotic protein expression,and cell apoptosis were measured.Results：PM2.5 exposure （0-200 μtg/ml） for 24 h resulted in increased ROS levels （arbitrary unit：201.00 ± 19.28,264.50 ± 17.91,305.05 ± 19.57,427.95 ＋ 18.32,and 436.70 ± 17.77） and malondialdehyde production （0.54 ± 0.05 nmol/mg prot,0.61 ± 0.06 nmol/mg prot,0.68 ± 0.05 nmol/mg prot,0.70 ± 0.05 nmol/mg prot,and 0.76 ± 0.05 nmol/mg prot）,diminished superoxide dismutase activity （6.47 ± 0.28 NU/mg prot,5.97 ± 0.30 NU/mg prot,5.15 ± 0.42 NU/mg prot,4.08 ± 0.20 NU/mg prot,and 3.76 ± 0.37 NU/mg prot）,and increased DNA damage and apoptosis in a dose-dependent manner in HaCaT cells.Moreover,cytochrome-c,caspase-3,and caspase-9 expression also increased proportionately with PM2.5 dosing.Conclusion：PM2.5 might elicit oxidative stress and mitochondria-dependent apoptosis that likely manifests as skin irritation and damage.
基金supported by the National Natural Science Foundation of China(21801152 and 21572110)We thank the Youth Innovation Science and Technology Plan of Colleges and Universities in Shandong Province(2021KJ076).
文摘A straightforward electrochemical reduction of benzo[b]thiophene 1,1-dioxides with HFIP as the hydrogen donor has been reported in an undivided cell under metal-free conditions.Moreover,the tolerance of various functional groups and scaled-up experiments showed the practicability and potential applications of this methodology.
基金This work was supported by the National Natural Science Foundation of China(21801152 and 21572110)the Natural Science Foundation of Shandong Province(ZR2019BB005 and ZR2019MB010).
文摘Main observation and conclusion A general and practical protocol for the construction of diversified sulfur heterocycles has been described through organic electrosynthesis means.In undivided cell,dihydrothiophenes,thiazolines and 1,4-dithiines could be easily generated from various availableβ-ketothioamides under metal-free and external oxidant-free conditions.
基金the National Natural Science Foundation of China(Nos.21801152 and 21572110)the Natural Science Foundation of Shandong Province(Nos.ZR2019BB005 and ZR2019MB010)for financial supportShao-Fei Ni acknowledge funding from the STU Scientific Research Foundation for Talents(NTF20022).
文摘Main observation and conclusion Through the intramolecular cyclization of N-methoxybenzamides,a simple and efficient method for constructing valuable isoindolinones under metal-free conditions was developed.The reaction was featured by employing low-cost catalyst,simple operation,100%atomic economy and excellent regioselectivity.Moreover,a detailed computational study on the reaction system has been performed to clarify the mechanism.
