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| 1 | Microbial aerosol characteristics in highly polluted and nearpristine environments featuring different climatic conditions显示文摘There is an increasing interest in understanding ambient bioaerosols due to their roles both in health and in climate. Here, we deployed an Ultraviolet Aerodynamic Particle Sizer to monitor viable(fluorescent) bioaerosol concentration levels at city centers(highly polluted) and their corresponding suburbs(near pristine)(total 40 locations) in 11 provinces featuring different climate zones in China between July 16 and 28, 2013. The concentration levels of viable bioaerosol particles(Bio PM) of [0.5 lm were measured, and corresponding percentages of Bio PM%(biological fraction of total PM) and Bio PM2.5%(biological fraction of PM2.5) in particulate matter(PM)and Bio PM, respectively, were determined. For some key cities, indoor viable bioaerosol levels were also obtained.In addition, bacterial structures of the air samples collected across these monitoring locations were studied using pyrosequencing. Bio PM concentration levels ranged from2.1 9 104 to 2.4 9 105/m3 for city centers [Bio PM% =6.4 %(±6.3 %)] and 0.5 9 104 to 4.7 9 105/m3 for suburbs [Bio PM% = 10 %(±8.7 %)]. Distinctive bioaerosol size distribution patterns were observed for different climate zones, e.g., some had fluorescence peaks at 3 lm, while the majority had peaks at 1 lm. Ambient bacterial aerosol community structures were also found different for different geophysical locations. Results suggest that there was a poor overall relationship between PM and Bio PM across 40 monitoring locations(R2= 0.081, two-tailed P value =0.07435). Generally, city centers had higher PM concentrations than suburbs, but not Bio PM and Bio PM%. Indoor bioaerosol levels were found at least tenfold higher than those corresponding outdoors. Bacillus was observed to dominate the bacterial aerosol community in the air sample. | Kai Wei Yunhao Zheng Jing Li Fangxia Shen Zhuanglei Zou Hanqing Fan Xinyue Li Chang-yu Wu Maosheng Yao | 2015 | Science Bulletin2015,60,16: | 10 |
| 2 | Negatively and positively charged bacterial aerosol concentration and diversity in natural environments显示文摘Bioaerosol charge information is of vital importance for their electrostatic collection. Here, electrostatic means and molecular tools were applied to studying bioaerosol charge dynamics. Positively or negatively charged bioaerosols were collected using an electrostatic sampler operated with a field strength of 1.1 kV cm 1 at a flow rate of 3 L min 1 for 40 min. Those with fewer or no charges bypassing the sampler were also collected using a filter at the downstream of the electrostatic sampler in one environment. The experiments were independently conducted three times in three different environments. The collected bacterial aerosols were cultured directly on agar plates at 26°C, and the colony forming units (CFU) were manually counted. In addition, the CFUs were washed off from the agar plates, and further subjected to polymerase chain reaction (PCR) and denaturing gradient gel electrophoresis (DGGE) for culturable diversity analysis. The results revealed remarkable differences in positively and negatively charged culturable bacterial aerosol concentration and diversity among the studied environments. In the office environment, negatively charged culturable bacterial aerosols appeared to dominate (P = 0.0489), while in outdoor and hotel environments both polarities had similar concentration levels (P = 0.078, P = 0.88, respectively). DGGE patterns for positively charged culturable bacterial aerosols were shown strikingly different from those of negatively charged regardless of the sampling environments. In addition, for each of the environments positively charged culturable bacterial aerosols collected were found to have more band pattern similarity with those positively charged for respective regions of agar plates than those negatively charged, and vice versa. The information developed here is useful for developing efficient electrostatic sampling protocols for bioaerosols. | SHEN FangXia KAI Wei YAO MaoSheng | 2013 | Chinese Science Bulletin2013,58,26: | 1 |
| 3 | Development of a novel conductance-based technology for environmental bacterial sensing显示文摘In this study, a simple impedance based technology for measuring bacterial concentrations was developed. The measurement system includes the signal amplification, copper probes and a sample loader. During the experiments, the conductance of Bacillus subtilis var niger, Pseudomonas fluorescens, and Escherichia coli were measured using the combination of a pre-amplifier and a lock-in amplifier. The conductance data were modeled verses the bacterial concentrations. Results indicated that the relationship between the conductance of bacterial suspensions and their concentrations follows a generic model: Y=C1+C2×e ( X/C3 ) , where Y is the conductance (S), X is the bacterial concentration (Number/mL: abbreviated to N/mL) for all species tested, and C1 3 are constants. Gram negative P. fluorescens and E. coli assumed similar conductance curves, which were flatter than that of gram positive B. subtilis var niger. For P. fluorescens and E. coli the culturing technique resulted in higher concentration levels (statistically significant) from 2 to 4 times that measured by the impedance based technology. For B. subtilis var niger, both methods resulted in similar concentration levels. These differences might be due to membrane types, initial culturability and the obtained conductance curves. The impedance based technology here was shown to obtain the bacterial concentration instantly, holding broad promise in realtime monitoring biological agents. | SHEN FangXia TAN MiaoMiao XU Hong XU ZhenCheng YAO MaoSheng | 2013 | Chinese Science Bulletin2013,58,4: | 1 |
| 4 | Nonlinear proinflammatory effect of short-term PM_(2.5)exposure:A potential role of lipopolysaccharide显示文摘The association between PM_(2.5)(particulate matter≤2.5μm)short-term exposure and its health effect is non-linear from the epidemiological studies.And this nonlinearity is suggested to be related with the PM_(2.5)heterogeneity,however,the underlying biological mechanism is still unclear.Here,a total of 38 PM_(2.5)filters were collected continuously for three weeks in winter Beijing,with the ambient PM_(2.5)varying between 10 and 270μg/m^(3).Human monocytes-derived macrophages(THP-1)were treated with PM_(2.5)water-soluble elutes at10μg/mL to investigate the PM_(2.5)short-term exposure effect from a proinflammatory perspective.The proinflammatory cytokine tumor necrosis factor(TNF)induced by the PM_(2.5)elutes at equal concentrations were unequal,showing the heterogeneity of PM_(2.5)proinflammatory potentials.Of the various chemical and biological components,lipopolysaccharide(LPS)showed a strong positive association with the TNF heterogeneity.However,some outliers were observed among the TNF-LPS association.Specifically,for PM_(2.5)from relatively clean air episodes,the higher LPS amount corresponded to relatively low TNF levels.And this phenomenon was also observed in the promotion tests by treating macrophages with PM_(2.5)elutes dosed with additional trace LPS.Gene expression analysis indicated the involvement of oxidative-stress related genes in the LPS signaling pathway.Therefore,a potential oxidative-stress-mediated suppression on the PM_(2.5)-borne LPS proinflammatory effect was proposed to be accounted for the outliers.Overall,the results showed the differential role of LPS in the heterogeneity of PM_(2.5)proinflammatory effects from a component-based perspective.Future experimental studies are needed to elucidate the signaling pathway of LPS attached on PM_(2.5)from different air quality episodes. | Fangxia Shen Mutong Niu Haoxuan Chen Ting Zhang Jing Li Haijie Tong Yan Wu | 2024 | Journal of Environmental Sciences2024,,2: | 0 |
| 5 | Bioaerosol nexus of air quality, climate system and human health显示文摘Aerosols of biological origins,known as bioaerosols,in addition to having the aerosol properties,have those of a living system that offers them some enabling functionalities.From science to technology,visible progress around the world has been made in bioaerosol field before and especially during the COVID-19 pandemic.Here the roles of bioaerosol across various disciplines,including air quality,climate and human health are highlighted and appreciated in light of Anthropocene and one health concept.In particular,we recognized the importance of aerobiology under haze air pollution,allergenic pollen and bioaerosol involvement in infectious and inflammation-related non-communicable diseases.Future interdisciplinary studies focusing on the chemical and biological process of microorganisms in air,airborne transmission of emerging pathogens and allergens and the association between bioaerosol exposure and the development and variations of human microbiome and immune response are needed to elucidate the interactions of bioaerosols with the earth system. | Fangxia Shen Maosheng Yao | 2023 | National Science Open2023,2,4: | 0 |