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There is large amount of high hardness sand in the water flow in Dadu river. The problem of sediment deposition is very prominent in the two early reservoirs, Gongzui reservoir and Tongjiezi reservoir. In order to decrease sediment deposition effectively and extend the service life of them, the sediment characteristics of Dadu river cascade hydropower stations are analysed, as well as changes of sediment deposition in Gongzui reservoir and Tongjiezi reservoir after Pubugou reservoir puts into operation. Flood forecast and pre-discharge operation theory are studied for utilizing the discarding water to improve sediment-flushing effect, and flood and sediment joint dispatching schemes of cascade reservoirs are proposed. In order to evaluate effects of joint dispatching schemes, SBED extended one-dimensional flushing sediment mathematical model of deposited reservoir is built, and the mathematical model is used for simulative computation of coming 20-years sediment-flushing effect. After that, the effects of different schemes are analyzed comparatively. Three conclusions can be drawn from the studying. Firstly, the sediment in Gongzui reservoir and Tongjiezi reservoir is obviously reduced after Pubugou reservoir puts into operation. Secondly, flood forecast, pre-discharge operation theory and creating sand-flushing conditions can obviously improve sediment-flushing effects and avoid wasting power generation water when the water levels and outflows of Pubugou reservoir, Gongzui reservoir and Tongjiezi reservoir are rationally controlled. Finally, the larger the inflows and the lower the water level of Gongzui reservoir and Tongjiezi reservoir is, the more obvious the sediment-flushing effects are. According to situations of power plant at the time, such as rules of flood controlling and operation requirements of flood discharge facilities, it is recommended that the inflow of Gongzui reservoir is controlled at about 4500m3/s, and timely lower the water levels of Gongzui reservoir and Tongjiezi reservoir to their dead water levels, when carrying out joint dispatching schemes.

Background and Aim: Delayed postpolypectomy hemorrhage is relatively common, with occasional extensive blood loss, endangering life. This study aimed to determine the factors associated with postoperative hemorrhage. Methods: The study was a retrospective cohort study of patients hospitalized for colonoscopic polypectomy at the Department of Gastroenterology and Hepatology, Tenth People's Hospital of Tongji University, China, between January and December 2015. Data on gender, age, bowel preparation, location, size, number of polyps, operative modality, pathology, and operation practitioner were collected. Patients were divided into two groups based on the presence or absence of postoperative hemorrhage. Results: A total of 1962 polyps were detected in patients and they underwent polypectomy; hemorrhage occurred in 41 cases. A correlation was demonstrated between postpolypectomy hemorrhage and each of the following factors: polyp size and operative modality. The odds ratio (OR) was 4.535 (95% confidence interval [CI], 2.331–8.823) for 1–2‐cm polyps, 4.008 (95% CI, 0.904–17.776) for 2–3‐cm polyps, and 22.407 (95% CI, 5.783–86.812) for ≥3‐cm polyps. Compared with argon plasma coagulation, OR was 9.128 (95% CI, 3.548–23.486) for endoscopic mucosal resection and 31.257 (95% CI, 7.009–139.395) for endoscopic submucosal dissection. Conclusions: The independent risk factors for delayed postpolypectomy hemorrhage include polyp size and operative modality. The study was a retrospective cohort analysis of patients hospitalized for colonoscopic polypectomy. A total of 1962 polyps were detected in patients and they underwent polypectomy; hemorrhage occurred in 41 cases. A correlation was demonstrated between postpolypectomy hemorrhage and each of the following factors: polyp size and operative modality. [ABSTRACT FROM AUTHOR]

Purpose: To study the effects of 5-amino salicylic acids (5-ASAs) on the incidence rates of inflammatory bowel disease (IBD)-associated colonic cancer (IBDACa) and colonic dysplasia (IBDADys), as well as to evaluate the chemopreventive effects of 5-ASAs on IBDACa/Dys., Methods: Searches for officially published clinical studies on the effects of 5-ASAs on the chemoprevention of IBDACa/Dys were conducted in both foreign-language databases, including PubMed (Medline), EMCC, OVID, and the Cochrane Library, and Chinese databases, including Wanfang, Weipu (VIP), and CNKI, as well as using Google Scholar. For literature matching the selection criteria, the statistical software RevMan was employed to calculate odds ratio (OR) values and 95% confidence intervals (CIs). Sub-group analysis was performed for different study design types and IBD types., Results: A total of fourteen papers were included in this study. The results of the analysis showed that compared with patients not using 5-ASAs, patients using 5-ASAs showed only 49% of the occurrence rate of IBDACa and IBDADys, OR = 0.49 (95% CI: 0.33-0.73). The OR of ulcerative colitis (UC) patients using 5-ASAs exhibiting UCCa/Dys was 0.44 (95% CI: 0.26-0.76)., Conclusion: The use of 5-ASAs exerts a chemopreventive effect against IBDACa/Dys.