Long-term deposition of fly ash regulates bacterial communities in different disturbance zones: Evidence from diversity, network complexity and predictive metabolic function.

The structural diversity and metabolic pathways formed by soil microbial-environmental factor interactions can be used to predict the differences in microbial ecological functions. The storage of fly ash (FA) has caused potential harm to the surrounding soil environment, whereas little is known about bacterial communities and environmental factor interactions in FA-disturbed areas. In this study, we selected two disturbed areas (DW: dry-wet deposition zone, LF: leachate flow zone) and two nondisturbed areas (CSO: control point soil, CSE: control point sediment) as the test areas and used high-throughput sequencing technology to investigate the bacterial communities. The results indicated that (1) FA disturbance significantly increased the electrical conductivity (EC), geometric mean diameter (GMD), soil organic carbon (SOC) and some potentially toxic metals (PTMs) (Cu, Zn, Se and Pb) of DW and LF and significantly decreased the AK of DW and the pH of LF (p < 0.05). (2) The relative abundance of Proteobacteria was significantly increased in the DW (p < 0.05). Similarly, the relative abundances of Proteobacteria and Firmicutes obviously increased in the LF (p < 0.001). Interestingly, the α and ß diversity of LF flora and the ß diversity of DW flora changed. (3) The order of influence of bacterial community structure was nutrient characteristics > physical properties > PTMs. Among all factors, AK (33.9 %) and pH (44.3 %) were the key environmental limiting factors for the bacterial community in the DW and the LF, respectively. (4) FA perturbation reduced the complexity, connectivity and modularity of the interaction network between bacteria and disturbed them by increasing the metabolic pathways that degrade pollutants. In conclusion, our results revealed the changes in the bacterial community and the main environmental driving factors under different pathways of FA disturbance; this information provides a theoretical basis for ecological environment management.

Contrast in soil microbial metabolic functional diversity to fertilization and crop rotation under rhizosphere and non-rhizosphere in the coal gangue landfill reclamation area of Loess Hills.

Very poor reclaimed soil quality and weak microbial activity occur in the reclamation area of a coal gangue landfill in the Loess Hills. The fourth and fifth years after farmland soil was reclaimed were studied, and the changes in and carbon source utilization characteristics of rhizosphere (R) and non-rhizosphere (S) soil microorganisms under organic and inorganic (OF), inorganic (F), and organic (O) fertilizer application and a control treatment (CK) in soybean (S) and maize (M) rotation systems were compared and analysed in Guljiao Tunlan, Shanxi Province, China. Biolog-EcoPlate technology was used to analyse the mechanism of soil characteristic change from the perspective of soil microbial metabolism function to provide a theoretical basis for reclamation and ecological reconstruction in this area. The average well colour development (AWCD) absorption and Shannon-Wiener index values of soybean and maize rhizosphere microorganisms were higher than those of non-rhizosphere microorganisms, and the mean value of the fertilizer treatment was higher than that for CK. Principal component analysis shows the main carbon sources that impact the functional diversity of the soybean rhizosphere and non-rhizosphere soil communities are a-cyclodextrin, a-D-lactose, ß-methyl D-glucoside, and glucose-1-phosphate and L-phenylalanine, while those for the maize rhizosphere and non-rhizosphere soil communities are D-cellobiose, glucose-1-phosphate, ß-methyl D-glucoside, methyl pyruvate, D-galactosate gamma lactone, D-mannitol, N-acetyl-D-glucosamine, D-galactosalonic acid, and L-serine. The comprehensive utilization score of the non-rhizosphere soil carbon source in the maize season increased with respect to that in the soybean season, and the maximum increase was 1.09 under the OF treatment. Redundancy analysis showed that the soil nutrient factors driving the changes in the metabolic function diversity index values of the rhizosphere and non-rhizosphere soil microbial communities in the different crop seasons in the reclamation area differed, but they were all related to the soil organic matter and available phosphorus. This may explain why OF treatment is the most beneficial to soil fertility under the rotation system in mining reclamation areas.

Effect of cigarette smoking on clinical outcomes of hospitalized Chinese male smokers with acute myocardial infarction.

BACKGROUND: Smoking is known to be a strong risk factor for premature atherosclerosis, acute myocardial infarction (AMI) and sudden cardiac death. According to a cross-sectional survey conducted in 2000 - 2001 in China, the prevalence of smoking among the Chinese men was 60.2%, the highest prevalence in the world. Up to date, the relationship between smoking and AMI in Chinese male smokers is still unclear. This study analyzed the baseline characteristics for male smokers hospitalized with AMI and investigated the effect of cigarette smoking on their clinical outcomes. METHODS: A total of 890 men aged 18 years or over with AMI were prospectively recruited from 1 January 2007 to 31 December 2009 from Shanxi Provincial People's Hospital. Patients were grouped into smokers and nonsmokers. The relationships between baseline characteristics and clinical outcomes were tested using either the chi-square test for trend for discrete variables or analysis of variance for continuous variables. RESULTS: Smokers accounted for 66.7% (594), more than twice of nonsmokers (296 (33.3%)), and were averaged 7 years younger ((56.61 ± 11.44) vs. (63.61 ± 11.62) years, P < 0.001). Smokers had the higher rate of TIMI flow grade 2 or 3 after thrombolytic therapy (42.4% vs. 24.5%, P = 0.002), 1 vessel disease (25.5% vs. 14.5%, P = 0.003) than nonsmokers. Smokers had better in-hospital outcome with lower in-hospital mortality rate than nonsmokers (6.2% vs. 10.8%, P = 0.023). CONCLUSIONS: Male smokers suffered from AMI in this study presented an average of 7 years earlier than nonsmokers and were more than twice as likely to have AMI as nonsmokers in China. Smoking appeared to result in earlier infarction, especially ST elevated myocardial infarction in otherwise healthier patients who are likely to survive.