Influence of a biofilm bioreactor on water quality and microbial communities in a hypereutrophic urban river.

Biofilms play an important role in degradation, transformation and assimilation of anthropogenic pollutants in aquatic ecosystems. In this study, we assembled a tubular bioreactor containing a biofilm substrate and aeration device, which was introduced into mesocosms to explore the effects of bioreactor on physicochemical and microbial characteristics of a hypereutrophic urban river. The biofilm bioreactor greatly improved water quality, especially by decreasing dissolved inorganic nitrogen (DIN) concentrations, suggesting that biofilms were the major sites of nitrification and denitrification with an oxygen concentration gradient. The biofilm bioreactor increased the abundance of planktonic bacteria, whereas diversity of the planktonic microbial community decreased. Sequencing revealed that Proteobacteria, Bacteroidetes, Planctomycetes, and Actinobacteria were the four predominant phyla in the planktonic microbial community, and the presence of the biofilm bioreactor increased the relative abundance of Proteobacteria. Variations in microbial communities were most strongly affected by the presence of the biofilm bioreactor, as indicated by principal component analysis (PCA) and redundancy analysis (RDA). This study provides valuable insights into changes in ecological characteristics associated with self-purification processes in hypereutrophic urban rivers, and may be of important for the application of biofilm bioreactor in natural urban river

Clinical characteristics of tracheobronchomalacia complicated with pulmonary infection in children and the significance of electronic fiberoptic bronchoscopy in diagnosis and treatment

Objective To analyze the clinical features of children with tracheobronchomalacia （TBM） complicated with pulmonary infection，and to explore the significance of fiberoptic bronchoscopy in the diagnosis and treatment of this disease. Methods Clinical data of 236 children admitted to our hospital due to recurrent pulmonary infection were collected. Among them， 37 children were diagnosed with TBM by fiberoptic bronchoscopy. Clinical features of TBM and fiberoptic bronchoscopy results were analyzed. The differences between TBM and non-TBM children were statistically compared. Results The proportion of TBM children aged<1 year was high （30/37）. The average age of TBM children was significantly younger than that of non-TBM counterparts， and the average length of hospital stay of TBM children was significantly longer than that of non-TBM counterparts， and the differences were statistically significant （both P < 0.05）. The main manifestations of TBM and non-TBM children were cough， wheezing and recurrent respiratory tract infection， and there were no statistical differences in the male-to-female ratio （all P > 0.05）. Fiberoptic bronchoscopy found mild and moderate TBM at a single site in TBM children， and favorable outcomes were obtained. Conclusion TBM is one of the important factors of recurrent pulmonary infection and wheezing in young children. It is challenging to identify the symptoms of TBM. Bronchoscopy is beneficial to timely diagnosis and treatment

Effects of aquatic nitrogen pollution on particle-attached ammonia-oxidizing bacteria in urban freshwater mesocosms.

Ammonia-oxidizing bacteria (AOB) attached to aquatic particles are important participants in ammonia oxidation within hypereutrophic urban river systems. To explore the effects of aquatic nitrogen pollution on particle-attached AOB in urban river, we utilized laboratory mesocosms to investigate the responses of abundances and community structure of particle-attached AOB to ammonium (NH4+) and glycine (C2H5NO2) amendments. The abundance and community structure of particle-attached AOB were determined with quantitative real-time polymerase chain reaction (qRT-PCR) analysis and high-throughput sequencing based on the AOB amoA gene, respectively. Most of the bacterial amoA sequences from different treatments were affiliated with uncultured Nitrosomonadaceae bacterium, uncultured Nitrosomonadales bacterium, and uncultured Nitrosomonas sp., which are closely associated with organic pollution. The species richness and diversity of particle-attached AOB communities increased with increasing NH4+ and glycine concentrations. Treatment effects contributed significantly to the variance in particle-attached AOB communities. Although, glycine was completely transformed to ammonium within a few days and ammonium amendments would change the community structure of particle-attached AOB, the effect of glycine on the particle-attached AOB community was regulated by both the resulting ammonium concentration, as well as organic matter availability to the heterotrophic bacteria. Results suggested that high anthropogenic nitrogen loadings appeared to promote higher particle-attached AOB richness and diversity in the hypereutrophic urban river, but the effect of organic nitrogen on the particle-attached AOB community was different from the effect of inorganic nitrogen. This study informs ammonia oxidization mechanisms in the hypereutrophic urban rivers, which contributes to remediation/restoration strategies

Short-term effects of atmospheric particulate matter on myocardial infarction: a cumulative meta-analysis

Atmospheric particulate matter (PM) is hypothesized to increase the risk of myocardial infarction (MI). However, the epidemiological evidence is inconsistent. We identified 33 studies with more than 4 million MI patients and applied meta-analysis and meta-regression to assess the available evidence. Twenty-five studies presented the effects of the PM level on hospitalization for MI patients, while eight studies showed the effects on mortality. An increase in PM10 was associated with hospitalization and mortality in myocardial infarction patients (RR per 10 μg/m3 = 1.011, 95 % CI 1.006–1.016; RR per 10 μg/m3 = 1.008, 95 % CI 1.004–1.012, respectively); PM2.5 also increased the risk of hospitalization and mortality in MI patients (RR per 10 μg/m3 = 1.024, 95 % CI 1.007–1.041 for hospitalization and RR per 10 μg/m3 = 1.012, 95 % CI 1.010–1.015 for mortality). The results of the cumulative meta-analysis indicated that PM10 and PM2.5 were associated with myocardial infarctionwith the addition of new studies each year. In conclusion, short-term exposure to high PM10 and PM2.5 levels revealed to increase risk of hospitalization and mortality for myocardial infarction. Policy support of pollution control and individual protection was strongly recommended

Properties of bacterial communities attached to artificial substrates in a hypereutrophic urban river

Abstract Bacterial communities of biofilms growing on artificial substrates were examined at two time periods (7 and 14 days) and two locations (lentic and lotic areas) in a hypereutrophic urban river of eastern China. Previous studies in this river network indicated that variations of microbial communities were the major factor affecting the distribution of antibiotic resistant genes highlighting the importance of understanding controls of microbial communities. Bacterial communities associated with biofilms were determined using epifluorescence microscopy and high-throughput sequencing. Results showed that sampling time and site had significant effects on the abundances of surface-associated bacteria. No significant differences were found in the number of surface-associated bacteria between two substrate types (filament vs. slide). Sequencing revealed microbial communities attached to artificial substrates in a hypereutrophic urban river were composed of 80,375 OTUs, and distributed in 47 phyla. Proteobacteria and Cyanobacteria/Chloroplast were the two dominant phyla, followed by Planctomycetes, Actinobacteria, Verrucomicrobia, Firmicutes and Bacteroidetes. Taxonomic composition showed ammonia-oxidizing microorganisms, fecal indicator bacteria and pathogens enriched in attached microbial communities, especially the ammonia-oxidizing Nitrosomonas bacteria. These results indicated that there were significant temporal and intra-river heterogeneity of attached microbial community structure, but no significant difference in community composition was detected between the two substrate types

Association between fibre intake and indoxyl sulphate/P-cresyl sulphate in patients with chronic kidney disease: meta-analysis and systematic review of experimental studies

Background and objective: Indoxyl sulphate (IS) and p-cresyl sulphate (PCS), which are difficult to excrete adequately out of the body, are closely related to the progression of chronic kidney disease (CKD) and various deuteropathy. Better than peritoneal dialysis (PD) and haemodialysis (HD), dietary fibre has been considered to reduce IS and PCS levels. In view of the absence of formal recommendations on fibre intake in CKD nutritional guidelines, we conducted this meta-analysis to assess the effects of dietary fibre on IS and PCS for CKD patients. Methods: The effects were pooled and expressed in terms of weighted mean difference (WMD) with 95% confidence interval (95% CI). Q test and I2 statistics were used to assess the heterogeneity. Results: A total of 12 relevant estimates from 7 reports, including 203 CKD patients, showed that dietary fibre significantly reduced their PCS level (WMD = −16.160, 95% CI: −23.824, −8.495). Conclusions: The meta-analysis produced a strong corroboration that dietary fibre intake does have a good therapeutic effect on patients with CKD. The conclusions need to be validated by randomised controlled experiments (RCT) with better design, larger samples, longer course of treatment and higher quality