Study on the Characteristics of Urban Air Pollution Based on Correspondence Analysis--A Case Study of Six Provincial Capitals in Central-south China

[Objective] The aim was to study the characteristics of urban air pollution on the basis of correspondence analysis.[Method] By using the correlated data from China Statistical Yearbook in 2010,a correspondence analysis on the air pollution indicators(like respirable particles,SO2 and NO2) of six provincial capitals in central-south China was carried out by means of SPSS software,and the characteristics of air pollution in the cities of China during different industrialization stages were summarized further.[Result] In the cities during early industrialization(like Nanning City and Guiyang City) and mineral resource-based cities(like Taiyuan City),the air was mainly polluted by SO2;for the cities in the middle industrialization(such as Changsha City,Wuhan City,Zhengzhou City and Chengdu City),the air was polluted by respirable particles chiefly;in the cities in late industrialization(like Guangzhou City and Shenzhen City) or completing industrialization(like Shanghai City),the air was mainly polluted by NO2;for the cities in pre-industrial stage(like Haikou City and Lhasa City),the characteristic of air pollution wasn't obvious.[Conclusion] The study could provide references for the control of urban air pollution in China in the further.

白藜芦醇对高糖环境下肾小管上皮细胞PTEN表达及纤维化效应的影响

观察白藜芦醇(resveratrol,Res)对高糖培养条件下的大鼠肾小管上皮细胞第10号染色体缺失的磷酸酶和张力蛋白同源基因(phosphatase and tensin homology deleted on chromosome ten,PTEN)表达的影响,探讨Res减轻高糖条件下肾小管上皮细胞纤维化病变效应的作用及可能机制。将高糖培养的大鼠肾小管上皮细胞(NRK-52E)给予Res或PTEN抑制剂SF1670预处理后,分别设正常糖组(NG)、正常糖+SF1670组(NS)、高糖组(HG)、高糖+SF1670组(HS)、高糖+不同浓度(5、10、25μmol·L^(-1))Res处理组。采取免疫荧光细胞化学法观察E-cadherin、α-SMA在肾小管上皮细胞中的表达和分布;Western blot法检测PTEN、E-cadherin、α-SMA、p-Akt^((Thr308))、collagen Ⅳ蛋白的表达变化;real-time PCR法检测PTEN mRNA的表达水平。结果显示,与NG组相比,HG组PTEN mRNA和蛋白表达减少,E-cadherin蛋白表达减少,而α-SMA、p-Akt^((Thr308))、collagenⅣ蛋白表达增多。与HG组相比,随Res剂量增加,PTEN mRNA和蛋白表达水平逐渐上调,E-cadherin蛋白表达水平逐渐上调,α-SMA、collagen Ⅳ、p-Akt^((Thr308))蛋白表达水平逐渐下调,呈量效依赖性。与NG组相比,NS组无明显差异。与HG组相比,HS组E-cadherin蛋白表达进一步减少,α-SMA、p-Akt^((Thr308))、collagen Ⅳ蛋白表达进一步增多,而PTEN mRNA和蛋白表达无明显差异。使用PTEN抑制剂后不影响PTEN,但其他蛋白表达变化均与Res处理后的效应相反,且加重了纤维化病变效应,提示SF1670产生作用是通过抑制PTEN,激活Akt,增加collagen Ⅳ等细胞外基质(extracellular matrix,ECM)的合成,从而促进纤维化。结果表明,Res可拮抗高糖介导的肾小管上皮细胞纤维化病变效应,其机制可能是通过上调PTEN抑制PI3K/Akt信号通路而实现的。