[Characteristics and Impact Factors of Number Concentration of Primary Biological Aerosol Particles in Beijing].

Primary biological aerosol particles (PBAP) are an important part of ambient aerosols. Both living and dead organisms not only influence human health and air quality but also play important roles in regulating certain atmospheric processes and affect the hydrological cycle and climate change. In this study, flow cytometry (FCM) was utilized in combination with the simultaneous use of permeant (SYBR Green I) and impermeant (propidium iodide, PI) nucleic acid fluorescent staining to detect and quantify the viable and dead airborne biological particles. At the same time, based on this method, the dead/viable PBAP in a Beijing urban area was detected and quantified. Moreover, the influence of environmental factors on the concentrations of primary biological aerosol particles was illuminated. The results showed that the media number concentration of dead and alive PBAP in the Beijing urban area during summer (1.03×106 m-3 and 7.43×105 m-3, respectively) were higher than those during winter (7.34×105 m-3and 6.18×105 m-3, respectively). Statistical analysis showed that there was no significant correlation between PBAP number concentration and environmental factors, i.e., meteorological conditions and air quality, showing a weak positive correlation with temperature and humidity and weak negative correlations with O3, maximum wind speed, and sunshine duration. The number concentration of PBAP was weakly correlated with the mass concentration of PM2.5 but positively correlated with that of coarse particulate matter (PM2.5-10). Both stable weather and dust transport could increase the number concentration of PBAP in Beijing.

CircRNA expression profiles and circRNA-miRNA-mRNA crosstalk in allergic rhinitis.

BACKGROUND: Circular RNAs (circRNAs) are involved in inflammation; however, their role in allergic rhinitis (AR) remains unclear. In this study, we analyzed circRNA expression and identified a circRNA-miRNA-mRNA network through which circRNAs regulate AR pathogenesis. METHODS: We analyzed circRNA, miRNA, and mRNA expression profiles in the nasal mucosa by high-throughput sequencing (HTS), using a fold-change >1.5 and p-value < 0.05 to pinpoint significantly differentially expressed (DE) circRNAs, miRNAs, and mRNAs in AR. A DEcircRNA-DEmiRNA-DEmRNA crosstalk network was then constructed using bioinformatics and statistical analysis. Gene ontology and Kyoto encyclopedia of genes and genomes pathway analyses were performed to identify the biological terms enriched in the network; whereas RT-PCR and Sanger sequencing were used to confirm the circRNAs. RESULTS: A total of 264 DEcircRNAs were identified by HTS, including 120 upregulated and 144 downregulated in AR compared to controls. A DEcircRNA-DEmiRNA-DEmRNA crosstalk network was constructed with 17 miRNAs, 11 circRNAs, 29 mRNAs, and 64 interaction pairs. These genes were involved in the Wnt signaling pathway, TNF biosynthesis, inflammatory responses, the PI3K-Akt signaling pathway, and Toll-like receptors. Of the 11 DEcircRNAs, hsa_circ_0008668 and circTRIQK were upregulated, whereas hsa_circ_0029853 and circRNA_01002 were downregulated in AR tissues. Sanger sequencing confirmed the back-splicing junctions of these circRNAs. CONCLUSIONS: We constructed a novel DEcircRNA-DEmiRNA-DEmRNA network for AR that provides a basis for future studies to investigate its underlying molecular mechanisms.

[Comparison of Chemical Components Characteristics of PM2.5 Between Haze and Clean Periods During Summertime in Lin'an].

PM2.5 samples were collected at a background site of the Yangtze River Delta in China, during summertime, of which the carbonaceous components, i.e., OC and EC, and water-soluble inorganic ions, including sulfate, nitrate, and ammonium, were quantified. The average concentrations of OC and EC in PM2.5 during summer at Lin'an were (14.3±3.95) µg·m-3 and (3.33±1.47) µg·m-3, respectively. Compared to an urban site, the correlation between OC and EC during summertime in Lin'an, which was a rural site, was relatively weak (R2=0.31, P<0.01). The concentrations of secondary inorganic aerosols (sulfate as SO42-, nitrate as NO3-, and ammonium as NH4+) were much higher than those of other water-soluble inorganic ions, with average values of (8.70±5.66), (2.04±1.07), and (3.25±2.29) µg·m-3, respectively. Based on long-term intensive observations, combined with the analysis of back trajectory and fire spots observations, it was revealed that regional transport and stable synoptic conditions both play important roles in controlling the variations in aerosol chemical components. During the transition from clean to hazy days, the EC and POC fractions showed no obvious variation; in contrast, the SOC fraction decreased obviously. Unlike for SOAs, relative contributions of sulfate and ammonia to PM2.5 increased during hazy days, suggesting enhanced chemical production via other pathways for these two secondary inorganic ions, probably through heterogeneous reactions.

[Characteristics Analysis of Sulfur Dioxide in Pearl River Delta from 2006 to 2010].

Based on the in-situ SO2 observation dataset from 2006 to 2010 in Pearl River Delta(PRD) , the temporal characteristics of SO2 are analyzed. The results show that the annual average volume fraction of surface SO2 in 2010 declines to a level below average values in recent years, with reducing the frequency of high concentration episodes occurring. The seasonal, monthly and diurnal characteristics of surface SO2 are influenced by particular weather conditions in the PRD. The Probability Distribution Function(PDF) of surface SO2 volume fraction are complicated. The PDF is different every month maybe caused by the variation of the seasonal factors.