PM2.5 aerosols were collected in forests along north latitude in boreal-temperate, temperate, subtropical and tropical climatic zones in eastern China, i.e., Changbai Mountain Nature Reserve （CB）, Dongping National ...PM2.5 aerosols were collected in forests along north latitude in boreal-temperate, temperate, subtropical and tropical climatic zones in eastern China, i.e., Changbai Mountain Nature Reserve （CB）, Dongping National Forest Park in Chongming Island （CM）, Dinghu Mountain Nature Reserve （DH）, Jianfengling Nature Reserve in Hainan Island （HN）. The mass concentrations of PM2.5, organic carbon （OC）, elemental carbon （EC）, water soluble organic carbon （WSOC） as well as concentrations of ten inorganic ions （F？, Cl？, NO3？, SO42？, C2O42？, NH4＋, Na＋, K＋, Ca2＋, Mg2＋） were determined. Aerosol chemical mass closures were achieved. The 24-hr average concentrations of PM2.5 were 38.8, 89.2, 30.4, 18 μg/m3 at CB, CM, DH and HN, respectively. Organic matter and EC accounted for 21%–33% and 1.3%–2.3% of PM2.5 mass, respectively. The sum of three dominant secondary ions （SO42-, NO3-, NH4＋） accounted for 44%, 50%, 45% and 16% of local PM2.5 mass at CB, CM, DH and HN, respectively. WSOC comprised 35%–65% of OC. The sources of PM2.5 include especially important regional anthropogenic pollutions at Chinese forest areas.展开更多
This paper explores the role of the secondary inorganic aerosol （SIA） species ammonium,NH4＋,nitrate,NO3-,and sulfate,SO24-,during haze and fog events using hourly mass concentrations of PM2.5 measured at a suburban...This paper explores the role of the secondary inorganic aerosol （SIA） species ammonium,NH4＋,nitrate,NO3-,and sulfate,SO24-,during haze and fog events using hourly mass concentrations of PM2.5 measured at a suburban site in Hangzhou,China.A total of 546 samples were collected between 1 April and 8 May 2012.The samples were analyzed and classified as clear,haze or fog depending on visibility and relative humidity （RH）.The contribution of SIA species to PM2.5 mass increased to ～50％ during haze and fog.The mass contribution of nitrate to PM2.5 increased from 11％ during clear to 20％ during haze episodes.Nitrate mass exceeded sulfate mass during haze,while near equal concentrations were observed during fog episodes.The role of RH on the correlation between concentrations of SIA and visibility was examined,with optimal correlation at 60％-70％ RH.The total acidity during clear,haze and fog periods was 42.38,48.38 and 45.51 nmol m-3,respectively,indicating that sulfate,nitrate and chloride were not neutralized by ammonium during any period.The nitrate to sulfate molar ratio,as a function of the ammonium to sulfate molar ratio,indicated that nitrate formation during fog started at a higher ammonium to sulfate molar ratio compared to clear and haze periods.During haze and fog,the nitrate oxidation ratio increased by a factor of 1.6-1.7,while the sulfur oxidation ratio increased by a factor of 1.2-1.5,indicating that both gaseous NO2 and SO2 were involved in the reduced visibility.展开更多
Recent studies have explored the relationship between aerosol optical depth (AOD) measurements by satellite sensors and concentrations of particulate matter with aerodynamic diameters less than 2.5 μm (PM2.5). Howeve...Recent studies have explored the relationship between aerosol optical depth (AOD) measurements by satellite sensors and concentrations of particulate matter with aerodynamic diameters less than 2.5 μm (PM2.5). However, relatively little is known about spatial and temporal patterns in this relationship across the contiguous United States. In this study, we investigated the relationship between US Environmental Protection Agency estimates of PM2.5 concentrations and Moderate Resolution Imaging Spectroradiometer (MODIS) AOD measurements provided by two NASA satellites (Terra and Aqua) across the contiguous United States during 2005. We found that the combined use of both satellite sensors provided more AOD coverage than the use of either satellite sensor alone, that the correlation between AOD measurements and PM2.5 concentrations varied substantially by geographic location, and that this correlation was stronger in the summer and fall than that in the winter and spring.展开更多
Alzheimer s disease,among the most common neurodegenerative disorders,is chara cterized by progressive cognitive impairment.At present,the Alzheimer’s disease main risk remains genetic ris ks,but major environmental ...Alzheimer s disease,among the most common neurodegenerative disorders,is chara cterized by progressive cognitive impairment.At present,the Alzheimer’s disease main risk remains genetic ris ks,but major environmental fa ctors are increasingly shown to impact Alzheimer’s disease development and progression.Microglia,the most important brain immune cells,play a central role in Alzheimer’s disease pathogenesis and are considered environmental and lifestyle"sensors."Factors like environmental pollution and modern lifestyles(e.g.,chronic stress,poor dietary habits,sleep,and circadian rhythm disorde rs)can cause neuroinflammato ry responses that lead to cognitive impairment via microglial functioning and phenotypic regulation.However,the specific mechanisms underlying interactions among these facto rs and microglia in Alzheimer’s disease are unclear.Herein,we:discuss the biological effects of air pollution,chronic stress,gut micro biota,sleep patterns,physical exercise,cigarette smoking,and caffeine consumption on microglia;consider how unhealthy lifestyle factors influence individual susceptibility to Alzheimer’s disease;and present the neuroprotective effects of a healthy lifestyle.Toward intervening and controlling these environmental risk fa ctors at an early Alzheimer’s disease stage,understanding the role of microglia in Alzheimer’s disease development,and to rgeting strategies to to rget microglia,co uld be essential to future Alzheimer’s disease treatments.展开更多
目的研究不同剂量直径≤2.5μm的细颗粒物(PM2.5)诱导卵清蛋白(OVA)致哮喘小鼠肺损伤的程度。方法雄性BALB/c小鼠被随机分为正常对照组、OVA哮喘组、(1、5、15)mg/m L PM2.5处理的OVA哮喘组。收集支气管肺泡灌洗液(BALF)进行Gimsa染色...目的研究不同剂量直径≤2.5μm的细颗粒物(PM2.5)诱导卵清蛋白(OVA)致哮喘小鼠肺损伤的程度。方法雄性BALB/c小鼠被随机分为正常对照组、OVA哮喘组、(1、5、15)mg/m L PM2.5处理的OVA哮喘组。收集支气管肺泡灌洗液(BALF)进行Gimsa染色观察白细胞数量,ELISA检测小鼠血清γ干扰素(IFN-γ)、白细胞介素17(IL-17)和IL-10的含量;实时定量PCR进行外周血单个核细胞(PBMC)Toll样受体4(TLR4)、核因子κB(NF-κB)的mRNA水平;Western blot法检测T细胞表达的T盒(T-bet)、维甲酸相关孤核受体γt(RORγt)和叉头盒P3(FOXP3)蛋白水平;HE染色观察小鼠肺组织病变情况。结果与对照组相比,OVA哮喘组小鼠的肺泡间隔增厚,肺泡腔增大,且出现较明显的炎性细胞浸润,BALF中与炎症反应相关的白细胞数目增多;与OVA哮喘组相比,15 mg/m L PM2.5诱导的哮喘小鼠上述变化极其明显。与对照组相比,OVA哮喘组小鼠血清中IFN-γ、IL-10显著降低,而IL-17显著增加;与OVA哮喘组相比,15 mg/m L PM2.5处理的OVA哮喘组IFN-γ、IL-10含量显著减少,而IL-17含量显著增加。与对照组相比,OVA哮喘组小鼠PBMC中TLR4、NF-κB表达量明显增加,与OVA哮喘组相比,15 mg/m L PM2.5处理OVA哮喘组TLR4、NF-κB表达量显著增加。与对照组相比,OVA哮喘组小鼠T-bet和FOXP3蛋白水平明显降低,RORγt蛋白水平明显升高;与OVA哮喘组相比,15 mg/m L PM2.5处理OVA哮喘组小鼠T-bet和FOXP3蛋白水平极显著降低,而RORγt蛋白水平显著增加。结论 15 mg/m L PM2.5通过激活TLR4/NF-κB信号通路促进OVA诱发的哮喘和肺损伤。展开更多
基金supported by the National Natrual Science Foundation of China (No. 20677036, 20877051)the Shanghai Leading Academic Disciplines (No. S30109)+1 种基金the Scientific Research Foundation for Returned Overseas Chinese Scholars, State Education Ministrysupported by the Graduate Innovative Fund from Shanghai University
文摘PM2.5 aerosols were collected in forests along north latitude in boreal-temperate, temperate, subtropical and tropical climatic zones in eastern China, i.e., Changbai Mountain Nature Reserve （CB）, Dongping National Forest Park in Chongming Island （CM）, Dinghu Mountain Nature Reserve （DH）, Jianfengling Nature Reserve in Hainan Island （HN）. The mass concentrations of PM2.5, organic carbon （OC）, elemental carbon （EC）, water soluble organic carbon （WSOC） as well as concentrations of ten inorganic ions （F？, Cl？, NO3？, SO42？, C2O42？, NH4＋, Na＋, K＋, Ca2＋, Mg2＋） were determined. Aerosol chemical mass closures were achieved. The 24-hr average concentrations of PM2.5 were 38.8, 89.2, 30.4, 18 μg/m3 at CB, CM, DH and HN, respectively. Organic matter and EC accounted for 21%–33% and 1.3%–2.3% of PM2.5 mass, respectively. The sum of three dominant secondary ions （SO42-, NO3-, NH4＋） accounted for 44%, 50%, 45% and 16% of local PM2.5 mass at CB, CM, DH and HN, respectively. WSOC comprised 35%–65% of OC. The sources of PM2.5 include especially important regional anthropogenic pollutions at Chinese forest areas.
基金supported by the National Natural Science Foundation of China (Grant Nos. 21190053 and 21177025)the Shanghai Science and Technology Commission of Shanghai Municipality (Grant Nos. 12DJ1400100 and 13XD 1400700)the Priority Fields for Ph.D. Programs Foundation of the Ministry of Education of China (Grant No.20110071130003)
文摘This paper explores the role of the secondary inorganic aerosol （SIA） species ammonium,NH4＋,nitrate,NO3-,and sulfate,SO24-,during haze and fog events using hourly mass concentrations of PM2.5 measured at a suburban site in Hangzhou,China.A total of 546 samples were collected between 1 April and 8 May 2012.The samples were analyzed and classified as clear,haze or fog depending on visibility and relative humidity （RH）.The contribution of SIA species to PM2.5 mass increased to ～50％ during haze and fog.The mass contribution of nitrate to PM2.5 increased from 11％ during clear to 20％ during haze episodes.Nitrate mass exceeded sulfate mass during haze,while near equal concentrations were observed during fog episodes.The role of RH on the correlation between concentrations of SIA and visibility was examined,with optimal correlation at 60％-70％ RH.The total acidity during clear,haze and fog periods was 42.38,48.38 and 45.51 nmol m-3,respectively,indicating that sulfate,nitrate and chloride were not neutralized by ammonium during any period.The nitrate to sulfate molar ratio,as a function of the ammonium to sulfate molar ratio,indicated that nitrate formation during fog started at a higher ammonium to sulfate molar ratio compared to clear and haze periods.During haze and fog,the nitrate oxidation ratio increased by a factor of 1.6-1.7,while the sulfur oxidation ratio increased by a factor of 1.2-1.5,indicating that both gaseous NO2 and SO2 were involved in the reduced visibility.
文摘Recent studies have explored the relationship between aerosol optical depth (AOD) measurements by satellite sensors and concentrations of particulate matter with aerodynamic diameters less than 2.5 μm (PM2.5). However, relatively little is known about spatial and temporal patterns in this relationship across the contiguous United States. In this study, we investigated the relationship between US Environmental Protection Agency estimates of PM2.5 concentrations and Moderate Resolution Imaging Spectroradiometer (MODIS) AOD measurements provided by two NASA satellites (Terra and Aqua) across the contiguous United States during 2005. We found that the combined use of both satellite sensors provided more AOD coverage than the use of either satellite sensor alone, that the correlation between AOD measurements and PM2.5 concentrations varied substantially by geographic location, and that this correlation was stronger in the summer and fall than that in the winter and spring.
基金supported by the National Natural Science Foundation of China,Nos.82071190 and 82371438(to LC)Innovative Strong School Project of Guangdong Medical University,No.4SG21230G(to LC)Scientific Research Foundation of Guangdong Medical University,No.GDMUM2020017(to CL)。
文摘Alzheimer s disease,among the most common neurodegenerative disorders,is chara cterized by progressive cognitive impairment.At present,the Alzheimer’s disease main risk remains genetic ris ks,but major environmental fa ctors are increasingly shown to impact Alzheimer’s disease development and progression.Microglia,the most important brain immune cells,play a central role in Alzheimer’s disease pathogenesis and are considered environmental and lifestyle"sensors."Factors like environmental pollution and modern lifestyles(e.g.,chronic stress,poor dietary habits,sleep,and circadian rhythm disorde rs)can cause neuroinflammato ry responses that lead to cognitive impairment via microglial functioning and phenotypic regulation.However,the specific mechanisms underlying interactions among these facto rs and microglia in Alzheimer’s disease are unclear.Herein,we:discuss the biological effects of air pollution,chronic stress,gut micro biota,sleep patterns,physical exercise,cigarette smoking,and caffeine consumption on microglia;consider how unhealthy lifestyle factors influence individual susceptibility to Alzheimer’s disease;and present the neuroprotective effects of a healthy lifestyle.Toward intervening and controlling these environmental risk fa ctors at an early Alzheimer’s disease stage,understanding the role of microglia in Alzheimer’s disease development,and to rgeting strategies to to rget microglia,co uld be essential to future Alzheimer’s disease treatments.
文摘目的研究不同剂量直径≤2.5μm的细颗粒物(PM2.5)诱导卵清蛋白(OVA)致哮喘小鼠肺损伤的程度。方法雄性BALB/c小鼠被随机分为正常对照组、OVA哮喘组、(1、5、15)mg/m L PM2.5处理的OVA哮喘组。收集支气管肺泡灌洗液(BALF)进行Gimsa染色观察白细胞数量,ELISA检测小鼠血清γ干扰素(IFN-γ)、白细胞介素17(IL-17)和IL-10的含量;实时定量PCR进行外周血单个核细胞(PBMC)Toll样受体4(TLR4)、核因子κB(NF-κB)的mRNA水平;Western blot法检测T细胞表达的T盒(T-bet)、维甲酸相关孤核受体γt(RORγt)和叉头盒P3(FOXP3)蛋白水平;HE染色观察小鼠肺组织病变情况。结果与对照组相比,OVA哮喘组小鼠的肺泡间隔增厚,肺泡腔增大,且出现较明显的炎性细胞浸润,BALF中与炎症反应相关的白细胞数目增多;与OVA哮喘组相比,15 mg/m L PM2.5诱导的哮喘小鼠上述变化极其明显。与对照组相比,OVA哮喘组小鼠血清中IFN-γ、IL-10显著降低,而IL-17显著增加;与OVA哮喘组相比,15 mg/m L PM2.5处理的OVA哮喘组IFN-γ、IL-10含量显著减少,而IL-17含量显著增加。与对照组相比,OVA哮喘组小鼠PBMC中TLR4、NF-κB表达量明显增加,与OVA哮喘组相比,15 mg/m L PM2.5处理OVA哮喘组TLR4、NF-κB表达量显著增加。与对照组相比,OVA哮喘组小鼠T-bet和FOXP3蛋白水平明显降低,RORγt蛋白水平明显升高;与OVA哮喘组相比,15 mg/m L PM2.5处理OVA哮喘组小鼠T-bet和FOXP3蛋白水平极显著降低,而RORγt蛋白水平显著增加。结论 15 mg/m L PM2.5通过激活TLR4/NF-κB信号通路促进OVA诱发的哮喘和肺损伤。
