Environmental factors and particle size shape the community structure of airborne total and pathogenic bacteria in a university campus.

Given the dense population on university campuses, indoor and outdoor airborne bacterial contamination may lead to the rapid spread of diseases in a university environment. However, there are few studies of the characteristics of airborne and pathogenic bacterial communities in different sites on a university campus. In this study, we collected particulate matter samples from indoor and outdoor locations at a university in Bengbu City, Anhui Province, China, and analyzed the community characteristics of airborne and pathogenic bacteria using a high-throughput sequencing technique. The results showed that the composition of the dominant airborne and pathogenic bacterial communities was consistent among sites at the phylum and genus levels, with differences in their relative abundance. There were significant differences in the structure of the airborne and pathogenic bacterial communities between indoor and outdoor sites (p < 0.05). An analysis of similarities (ANOSIM) indicated that the structure of airborne bacterial communities in indoor sites was influenced by the room occupancy rate, ventilation conditions, and the extent of indoor furnishing (p < 0.05), while the structure of pathogenic bacterial communities was influenced by the number of individuals and spatial dimensions (p < 0.05). The impact of particle size on the structure of airborne and pathogenic bacterial communities was relatively minor. A total of 194 suspected pathogenic bacterial species were identified, accounting for 0.0001-1.3923% of the total airborne bacteria, all of which were conditional pathogens. Among them, Saccharopolyspora rectivirgula, Acinetobacter johnsonii, and Moraxella osloensis exhibited relatively high relative abundance, accounting for 24.40, 16.22, and 8.66% of the total pathogenic bacteria, respectively. Moreover, 18 emerging or re-emerging pathogenic bacterial species with significant implications for human health were identified, although their relative abundance was relatively low (0.5098%). The relative abundance of pathogenic bacteria in indoor environments was significantly higher than outdoors, with the laboratory and dormitory having the highest levels. The findings of this study provide valuable guidance for the prevention and control of airborne bacterial contamination and the associated health risks in both a campus environment and other public spaces with high occupancy rates.

Source analysis and health risk assessment of polycyclic aromatic hydrocarbon (PAHs) in total suspended particulate matter (TSP) from Bengbu, China.

The polycyclic aromatic hydrocarbon (PAH) concentrations in total suspended particulate matter (TSP) samples collected from October, 2021 to September, 2022 were analyzed to clarify the pollution characteristics and sources of 16 PAHs in the atmospheric TSP in Bengbu City. The ρ(PAHs) concentrations ranged from 1.71 to 43.85 ng/m3 and higher concentrations were detected in winter, followed by spring, autumn, and summer. The positive matrix factorization analysis revealed that, in spring and summer, PAH pollution was caused mainly by industrial emissions, gasoline and diesel fuel combustion, whereas in autumn and winter, it was coal, biomass and natural gas combustion. The cluster and potential source factor analyses showed that long-range transport was a significant factor. During spring, autumn, and winter, the northern and northwestern regions had a significant impact, whereas the coastal area south of Bengbu had the greatest influence in summer. The health risk assessment revealed that the annual total carcinogenic equivalent concentration values for PAHs varied from 0.0159 to 7.437 ng/m3, which was classified as moderate. Furthermore, the annual incremental lifetime cancer risk values ranged from 1.431 × 10-4 to 3.671 × 10-3 for adults and from 6.823 × 10-5 to 1.749 × 10-3 for children, which were higher than the standard.

[Studies on chemical constituents from stem barks of Fraxinus paxiana].

OBJECTIVE: To investigate the chemical constituents of Fraxinus paxiana. METHOD: The chemical constituents were isolated and purified by chromatographic techniques and the structures of the compounds were identified with or by spectroscopic methods. RESULT: Fifteen compounds were obtained from the methanol extract of F. paxiana and their structures were elucidated as esculin (1), esculetin (2), fraxin (3), fraxetin (4), salidroside (5), osmanthuside H (6), liriodendrin (7), 3-(4-beta-D-glucopyranosyloxy-3-methoxy)-phenyl-2E-propenol (8), threo-syringylglycerol (9), euscaphic acid (10), 3-hydroxy-1-(4-hydroxy-3, 5-dimethoxyphenyl)-1-propanone (11), omega-hydroxypropioguaiacone (12), sinapyladehyde (13), betulinic acid (14) and mannitol (15). CONCLUSION: All compounds were obtained from this plant for the first time.

[Effects of different types and standard of processing vinegaron inherent constituents in rhizoma of Corydalis yanhusuo].

OBJECTIVE: To investigate the effects of processing adjuvants-different types of processing vinegar on effective constituents in rhizoma of Corydalis yanhusuo, and evaluate the quality of different types of vinegar in China. METHOD: The HPLC method was adopted to determine the extraction solubility of dl-tetrahydropalmation and total alkaloids in rhizoma of Corydalis yanhusuo processed by vinegar. The sample extracts were separated on kromasil ODS column with mobile phase of methanol-1% phosphoric acid solution(65:35) and detection wavelength was 280 nm. RESULT: There was a remarkable increase in extraction solubility of dl-tetrahydropalmation and total alkaloids in the rhizoma of Corydalis yanhusuo processed by the vinegar products with high content of total acids or with known trademarks. CONCLUSION: Some types of vinegar with known trademarks had been preliminarily selected for the process of Chinese traditional medicine and they also met the requitrement of processing adjuvants with medicine grade. The results will be benefited to the foundation of standardization of vinegar.

[Determination of synephrine and N-methyltyramine in Pericarpium Citri Reticulatae viride by HPLC].

OBJECTIVE: To establish a quantitative method for determination of synephrine and N-methyltyramine in Citri Reticulatae. METHOD: Samples were extracted with 30% methanol. ODS column was used with methanol-water-sodium dodecyl sulfate (55:45:0.1) as mobile phase. Detection wavelength was 285 nm. RESULT: Synephrine and N-methyltyramine in sample solution were well separated. Linearity of synephrine was good (r = 0.9999) in range of 0.35-11.24 microg. The average recovery was 97.1%, and RSD of repeatability was 1.9%. CONCLUSION: This method can be used for quality control of Citri Reticulatae.