To investigate the effects of silver nanoparticles(Ag NPs)and low temperature double-pressure on the wastewater treatment efficacy and the microbial community structure of constructed wetlands,a pilot-scale vertical f...To investigate the effects of silver nanoparticles(Ag NPs)and low temperature double-pressure on the wastewater treatment efficacy and the microbial community structure of constructed wetlands,a pilot-scale vertical flow constructed wetland was set up to treat synthetic wastewater under laboratory conditions.By measuring the effluent concentration of ammonia nitrogen(NH_(4)^(+)-N),total nitrogen(TN),total phosphorus(TP),chemical oxygen demand(COD),and the diversity,richness,and community structure of microorganisms of the upper and lower soil layers in the wetland,the nutrient removal effect of the constructed wetland and the changes in the microflora of the soil layer were studied.The results reveal that the correlation coefficients between the removal rates of TN and NH_(4)^(+)-N and the temperature are 0.463 and 0.692,respectively,indicating a significant positive correlation.From the warm to the cold season,both the diversity and richness of microorganisms in the lower soil layer of wetlands are inhibited under the double-pressure of Ag NPs and low temperature,and the abundances of the denitrogenation functional bacteria such as Candidatus nitrososphaera,Sulfuritalea,Anaeromyxobacter,Candidatus solibacter,Nitrospira,and Zoogloea are altered.Low temperature and Ag NPs exposure can thus affect the wastewater treatment performance of constructed wetlands,possibly because of the seasonal changes of the microflora.展开更多
目的建立人3型副流感病毒(human parainfluenza virus type 3,HPIV3)感染小鼠模型,并研究其免疫应答特点。方法用HPIV3兰州分离株HPIV3LZ1728C19毒株鼻腔接种BALB/c小鼠,每天检测体温和体质量。用ELISA检测血清HPIV3特异性IgG、IgA滴度...目的建立人3型副流感病毒(human parainfluenza virus type 3,HPIV3)感染小鼠模型,并研究其免疫应答特点。方法用HPIV3兰州分离株HPIV3LZ1728C19毒株鼻腔接种BALB/c小鼠,每天检测体温和体质量。用ELISA检测血清HPIV3特异性IgG、IgA滴度,实时定量PCR检测鼻腔灌洗液和肺组织病毒滴度,流式细胞术检测外周血、肺、脾淋巴细胞中的HPIV3特异性IFN-γCD4^(+)和IFN-γCD8^(+)T细胞,酶联免疫斑点法检测分泌HPIV3特异性IgG/IgA的B淋巴细胞,肺组织切片观察病理变化。结果感染后第3天,小鼠鼻腔和肺的病毒负载量分别到达峰值104拷贝/ml鼻洗液和107拷贝/g组织,肺部发生炎症性病理变化。感染组早期体质量增加显著滞后于对照组(感染后第3天:t=4.64,P<0.05)。感染组血清中HPIV3特异性IgG(t=2.94,P<0.05)和IgA水平(t=18.66,P<0.05)显著增高,外周血、肺、脾均出现HPIV3特异性抗体分泌淋巴细胞。病毒感染诱导小鼠肺产生记忆性IFN-γCD8^(+)T和IFN-γCD4^(+)T细胞应答,脾和外周血产生IFN-γCD4^(+)T细胞应答。结论成功建立了HPIV3感染小鼠动物模型,感染小鼠产生了显著的肺黏膜体液和细胞免疫应答。展开更多
The excellent bactericidal performance of silver nanoparticles （Ag NPs） has led to their wide applications, resulting in increasing concerns about their potential environmental impacts. This study evaluated the infl...The excellent bactericidal performance of silver nanoparticles （Ag NPs） has led to their wide applications, resulting in increasing concerns about their potential environmental impacts. This study evaluated the influences of different concentrations of Ag NPs （0, 1, 10, and 100 μg g^-1 dry soil） on the ammonia-oxidizing microorganisms in soil at cultivation temperatures of 25 and 5 ℃ for 37 d. The results showed that 1μg g^-1 dry soil of Ag NPs had no acute effects on the ammonia-oxidizing microorganisms. However, 10 and 100μg g^-1 dry soil of Ag NPs levels were found to significantly inhibit the activities of soil nitrification, with a decrease of 69.89% and 94.55%, respectively, at 25 ℃ and 61.65% and 83.79%, respectively, at 5℃ compared to the control （0 μg g^-1 dry soil of Ag NPs）. These levels of Ag NPs also obviously decreased soil urease activity from about 380.47 ± 0.07 （at 5℃） and 529.76 ± 13.44 （at 25℃） mg N g^-1 dry soil d^-1 to 61.70 ± 2.97 and 68.29 ± 8.22 mg N g^-1 dry soil d^-1, respectively, after 37 d of cultivation. Quantitative polymerase chain reaction showed the abundance of ammonia-oxidizing archaea and bacteria. For the same exposure time, the effects of Ag NPs on the activities of ammonia-oxidizing microorganisms and urease decreased with decreasing temperature. The threshold concentration of Ag NPs that induced negative effects on ammonia-oxidizing microorganisms was higher at 5 -C than at 25 -C. Therefore, the temperature has a major impact on the toxicity of Ag NPs to ammonia-oxidizing microorganisms and on the urease activity, with toxicity being reduced with decreasing temperature.展开更多
基金The National Natural Science Foundation of China(No.50909019,51479034)the Fundamental Research Funds for the Central Universities(No.2242019K40064)。
文摘To investigate the effects of silver nanoparticles(Ag NPs)and low temperature double-pressure on the wastewater treatment efficacy and the microbial community structure of constructed wetlands,a pilot-scale vertical flow constructed wetland was set up to treat synthetic wastewater under laboratory conditions.By measuring the effluent concentration of ammonia nitrogen(NH_(4)^(+)-N),total nitrogen(TN),total phosphorus(TP),chemical oxygen demand(COD),and the diversity,richness,and community structure of microorganisms of the upper and lower soil layers in the wetland,the nutrient removal effect of the constructed wetland and the changes in the microflora of the soil layer were studied.The results reveal that the correlation coefficients between the removal rates of TN and NH_(4)^(+)-N and the temperature are 0.463 and 0.692,respectively,indicating a significant positive correlation.From the warm to the cold season,both the diversity and richness of microorganisms in the lower soil layer of wetlands are inhibited under the double-pressure of Ag NPs and low temperature,and the abundances of the denitrogenation functional bacteria such as Candidatus nitrososphaera,Sulfuritalea,Anaeromyxobacter,Candidatus solibacter,Nitrospira,and Zoogloea are altered.Low temperature and Ag NPs exposure can thus affect the wastewater treatment performance of constructed wetlands,possibly because of the seasonal changes of the microflora.
文摘目的建立人3型副流感病毒(human parainfluenza virus type 3,HPIV3)感染小鼠模型,并研究其免疫应答特点。方法用HPIV3兰州分离株HPIV3LZ1728C19毒株鼻腔接种BALB/c小鼠,每天检测体温和体质量。用ELISA检测血清HPIV3特异性IgG、IgA滴度,实时定量PCR检测鼻腔灌洗液和肺组织病毒滴度,流式细胞术检测外周血、肺、脾淋巴细胞中的HPIV3特异性IFN-γCD4^(+)和IFN-γCD8^(+)T细胞,酶联免疫斑点法检测分泌HPIV3特异性IgG/IgA的B淋巴细胞,肺组织切片观察病理变化。结果感染后第3天,小鼠鼻腔和肺的病毒负载量分别到达峰值104拷贝/ml鼻洗液和107拷贝/g组织,肺部发生炎症性病理变化。感染组早期体质量增加显著滞后于对照组(感染后第3天:t=4.64,P<0.05)。感染组血清中HPIV3特异性IgG(t=2.94,P<0.05)和IgA水平(t=18.66,P<0.05)显著增高,外周血、肺、脾均出现HPIV3特异性抗体分泌淋巴细胞。病毒感染诱导小鼠肺产生记忆性IFN-γCD8^(+)T和IFN-γCD4^(+)T细胞应答,脾和外周血产生IFN-γCD4^(+)T细胞应答。结论成功建立了HPIV3感染小鼠动物模型,感染小鼠产生了显著的肺黏膜体液和细胞免疫应答。
基金supported by the National Natural Science Foundation of China (No. 51479034)the Fundamental Research Funds for the Central Universities of China (No. 2242016R30008)
文摘The excellent bactericidal performance of silver nanoparticles （Ag NPs） has led to their wide applications, resulting in increasing concerns about their potential environmental impacts. This study evaluated the influences of different concentrations of Ag NPs （0, 1, 10, and 100 μg g^-1 dry soil） on the ammonia-oxidizing microorganisms in soil at cultivation temperatures of 25 and 5 ℃ for 37 d. The results showed that 1μg g^-1 dry soil of Ag NPs had no acute effects on the ammonia-oxidizing microorganisms. However, 10 and 100μg g^-1 dry soil of Ag NPs levels were found to significantly inhibit the activities of soil nitrification, with a decrease of 69.89% and 94.55%, respectively, at 25 ℃ and 61.65% and 83.79%, respectively, at 5℃ compared to the control （0 μg g^-1 dry soil of Ag NPs）. These levels of Ag NPs also obviously decreased soil urease activity from about 380.47 ± 0.07 （at 5℃） and 529.76 ± 13.44 （at 25℃） mg N g^-1 dry soil d^-1 to 61.70 ± 2.97 and 68.29 ± 8.22 mg N g^-1 dry soil d^-1, respectively, after 37 d of cultivation. Quantitative polymerase chain reaction showed the abundance of ammonia-oxidizing archaea and bacteria. For the same exposure time, the effects of Ag NPs on the activities of ammonia-oxidizing microorganisms and urease decreased with decreasing temperature. The threshold concentration of Ag NPs that induced negative effects on ammonia-oxidizing microorganisms was higher at 5 -C than at 25 -C. Therefore, the temperature has a major impact on the toxicity of Ag NPs to ammonia-oxidizing microorganisms and on the urease activity, with toxicity being reduced with decreasing temperature.
