Standing waves of the stepped dropshaft in a deep tunnel stormwater system.

The deep tunnel stormwater system, consisting of dropshafts and underground tunnels, is used to alleviate or prevent urban water problems associated with extreme rainfall events. The stepped dropshaft can transport surface runoff to the tunnels with high energy dissipation, low risk of cavitation and good exhaust performance, which well meets the requirement of the deep tunnel stormwater system. In the present study, the characteristics of the standing wave were investigated by experiments and numerical simulations, including the peak, trough and length of the standing wave. The flow regimes were divided into the nappe flow, the transition flow and the skimming flow with the increase of discharge, in which the standing wave mainly occurs on the external wall under the nappe flow and the transition flow. Influences of inflow discharge and dropshaft geometries were analyzed, including step rotation angle, relative step height and dropshaft curvature. The relations of the characteristics of standing wave with these effect factors were obtained. The maximum discharge capacity of the stepped dropshaft was established by considering that the standing wave just reached the above steps, which could be useful for the design and safe operation of the stepped dropshaft.

Clinical and laboratory features and factors predicting disease severity in pediatric patients with hemorrhagic fever with renal syndrome caused by Hantaan virus.

The clinical features and factors associated with disease severity in children with hemorrhagic fever with renal syndrome (HFRS) have not been well characterized. This study analyzed the clinical and laboratory factors associated with disease severity in children with HFRS caused by Hantaan virus. Data in pediatric patients with HFRS were retrospectively collected from Xi'an Children's Hospital over a 9-year period. Independent factors associated with disease severity were identified. Nomogram predicting disease severity was constructed based on variables filtered by feature selection. In total, 206 children with HFRS were studied. Fever, digestive tract symptoms, headache, backache, bleeding, and renal injury signs were the common symptoms. Elevated white blood cell, reduced platelet, hematuria, proteinuria, coagulation abnormalities, increased blood urea nitrogen (BUN) and procalcitonin (PCT), decreased estimated glomerular filtration rate and low serum Na+ , Cl- , and Ca2+ were the common laboratory findings. In the 206 patients, 21 patients had critical type disease and 4 patients (1.9%) died. Hydrothorax, hypotension and cerebral edema/cerebral herniation at hospital admission were independent clinical characteristics, and neutrophil %, prothrombin activity, PCT, BUN, and Ca2+ at hospital admission were independent laboratory factors associated with critical disease. Feature selection identified BUN, PCT and prothrombin time as independent factors related to critical disease. A nomogram integrating BUN and PCT at admission was constructed and calibration showed high accuracy for the probability prediction of critical disease. In conclusion, this study characterized the clinical and laboratory features and constructed a nomogram predicting disease severity in pediatric HFRS, providing references for disease severity evaluation in managing children HFRS.

Association of 5-Hydroxytryptamine 3 Receptor Antagonists With the Prognosis of Liver Failure.

Liver failure is a severe clinical syndrome with high mortality. 5-Hydroxytryptamine 3 receptor antagonists (5-HT3RAs) can reduce liver damage in animal models. We investigated whether 5-HT3RAs may improve the prognosis of liver failure. We analyzed the 28 and 90 days mortality of liver failure patients in relation to the use of 5-HT3RAs using data from a tertiary hospital in northwest China. According to the use of 5-HT3RAs, 419 patients with liver failure (46 acute, 93 sub-acute, 44 chronic, 236 acute on chronic) were divided into 5-HT3RA group (n = 105) and control group (n = 314). 5-HT3RAs were associated with decreased 28 days (HR 0.18, 95% CI 0.10-0.34, p < 0.001) and 90 days (HR 0.21, 95% CI 0.13-0.33, p < 0.001) mortality. After propensity score matching (PSM) (n = 67 in each group), 5-HT3RAs were still significantly associated with reduced 28 days (HR 0.10, 95%CI 0.04-0.26, p < 0.001) and 90 days (HR 0.16, 95%CI 0.08-0.31, p < 0.001) mortality. 5-HT3RA group patients had significantly higher 28 and 90 days survivals than controls both before and after PSM (all p < 0.001). This study shows that 5-HT3RAs are associated with increased survival of liver failure patients and thus may be used to treat liver failure if the findings are confirmed by additional studies.

Advances in the use of chloroquine and hydroxychloroquine for the treatment of COVID-19.

Coronavirus Disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is spreading worldwide. Antiviral therapy is the most important treatment for COVID-19. Among the drugs under investigation, anti-malarials, chloroquine (CQ) and hydroxychloroquine (HCQ), are being repurposed as treatment for COVID-19. CQ/HCQ were shown to prevent receptor recognition by coronaviruses, inhibit endosome acidification, which interferes with membrane fusion, and exhibit immunomodulatory activity. These multiple mechanisms may work together to exert a therapeutic effect on COVID-19. A number of in vitro studies revealed inhibitory effects of CQ/HCQ on various coronaviruses, including SARS-CoV-2 although conflicting results exist. Several clinical studies showed that CQ/HCQ alone or in combination with a macrolide may alleviate the clinical symptoms of COVID-19, promote viral conversion, and delay disease progression, with less serious adverse effects. However, recent studies indicated that the use of CQ/HCQ, alone or in combination with a macrolide, did not show any favorable effect on patients with COVID-19. Adverse effects, including prolonged QT interval after taking CQ/HCQ, may develop in COVID-19 patients. Therefore, current data are not sufficient enough to support the use of CQ/HCQ as therapies for COVID-19 and increasing caution should be taken about the application of CQ/HCQ in COVID-19 before conclusive findings are obtained by well-designed, multi-center, randomized, controlled studies.