ObjectivesTo systematically review the correlation between maternal serum selenium levels during pregnancy and premature birth.MethodsDatabases including PubMed, The Cochrane Library, EMbase, Web of Science, CNKI and CBM were searched to collect studies on correlation between maternal serum selenium levels during pregnancy with preterm birth in the offspring from inception to January, 2020. Two reviewers independently screened literature, extracted data and evaluated risk of bias of the included literature. Then, meta-analysis was conducted by using RevMan 5.3 software.ResultsA total of 12 studies involving 2 484 patients were included. The results of meta-analysis showed that compared with control group, the preterm group had lower serum selenium levels in pregnant females (SMD=−0.89, 95%CI −1.56 to −0.22, P=0.01). The results of the subgroup analysis showed that heterogeneity among subjects was still large when grouped accorcding to the continent to which a country belongs, the time of blood sample collection and test method in pregnant females.ConclusionsLow maternal serum selenium levels during pregnancy may increase the risk of preterm birth. Due to the limitation of the quantity and quality of the included studies, the above conclusions are required to be verified by more high quality studies.
ObjectiveTo evaluate the evidence of the experience with medical sewage treatment procedures in medical institutions in China. MethodsDatabases including CNKI, WanFang Data, PubMed, Web of Science, and EBSCO were electronically searched to collect studies on the medical sewage treatment process, flow, and specifications in medical institutions in China. We used the quality evaluation system to classify and grade the experiences based on the principles and methods of evidence-based science and performed a descriptive analysis. ResultsAfter the SARS pandemic in 2003, China systematically established and standardized the technical criteria of medical sewage treatment and discharge. Moreover, a prevention system for the epidemic using medical sewage was constructed, which guaranteed that the quality of medical sewage treatment and discharge would meet the criteria and protect the citizens, and the technical specifications of medical sewage treatment would progress and increase strictly. At present, medical sewage treatment in medical institutions in China was based on mechanical and biological methods, and disinfection was mainly performed using chlorine and its compounds, ozone, and ultraviolet light. ConclusionThe COVID-19 pandemic requires a higher quality of medical sewage treatment and discharge criteria for medical institutions in China. To meet these criteria, all medical institutions in China should check, replace, and update their old facilities; strengthen personnel training and effectively ensure the quality of medical sewage treatment.