Stormwater runoff is generally characterized as non-point source pollution. In the present study, antibiotic concentration and antibiotic susceptibilities of cultivable heterotrophic bacteria were investigated in two small shallow urban lakes before and after strong storm event. Several antibiotics, lactose-fermenting bacteria and cultivable heterotrophic bacteria concentrations increased in surface water and/or surface sediment of two small urban lakes (Lake Xuanwu and Wulongtan) after strong storm event. In general, the frequencies of bacteria showing resistance to nine antibiotics increased after storm event. Based on the 16S rRNA genes of 50 randomly selected isolates from each water sample of two lakes, Aeromonas and Bacillus were dominant genera in samples from two lakes, while genera Proteus and Lysinibacillus were the third abundant genera in Lake Xuanwu and Wulongtu, respectively. Presences of nine antibiotic resistance genes (ARGs) in the 100 isolates were detected and most of these isolates harbored at least two ARGs with different functions. The detection frequency of ARGs in Gram-negative isolates was higher than that in Gram-positive isolates. The most prevalent integron in 100 isolates was int(II) (n = 28), followed by int(I) (n = 17) and int(III) (n = 17). Our results indicate that strong storm events potentially contribute to the transfer of ARGs and antibiotic-resistant bacteria from land-sewer system to the urban Lakes.
This study presents a quantitative assessment of urbanization effects on hydrological runoff and drainage network in the city of Hohhot, China. The evolution of urban spatial morphology for the historical years (1987-2010) and projected year (2020) is described by changes in geographic information system (GIS)-based land use maps and further represented in hydrological parameters in the Storm Water Management Model (SWMM) simulation. The results show the levels of service of historical drainage were too low to have dominant impacts on flood risks, and hence a significant upward trend in catchment runoff response was observed over time. Comparisons with changes in system overloading indicate that the relative increase in flood risk is greatest at the early stage of urbanization with relatively low levels of development. The proposed adaptation measures based on a cost-effective optimal approach was found feasible to significantly improve the drainage performance and mitigate the increasing flooding impacts.
Background and Aim
Even though endoscopic submucosal dissection is an important endoscopic resection technique for gastrointestinal neoplasms, there are chances that postoperative esophageal stricture might take place as a side effect. Steroid applications were reported to be effective for the prevention of stricture formation. Therefore, this study aims to evaluate the efficacy and safety of different steroid applications.
Methods
Eligible studies published on PubMed, the Cochrane Library, Embase, Web of Science, and Chinese Biomedical Literature Database before August 2018 were reviewed. The preventions were divided as placebo/no treatment, long‐term oral steroid (LOS), median‐term oral steroid, short‐term oral steroid, single‐dose steroid injection, multiple‐dose steroid injection, topical superficial steroid, steroid injection combined with oral steroid, and preemptive endoscopic balloon dilatation. The primary outcomes were postoperative esophageal stricture rate and endoscopic balloon dilatation sessions required. Complications were also analyzed.
Results
A total of 19 studies were included. The network meta‐results illustrated that compared with the placebo, all kinds of steroid interventions were associated with lower rates of postoperative esophageal stenosis and less number of endoscopic balloon dilatation sessions. Moreover, combined therapy was no better than single regimen therapy. No significant differences between various steroid applications in the incidence of complications were spotted during this study. Based on the results of the network and clustered ranking, LOS might be the superior prevention for postoperative stricture with satisfying efficacy.
Conclusion
The present study showed that LOS appears to be the optimal prevention method for postoperative stricture formation.
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