Effects of switching redox conditions on sediment phosphorus immobilization by calcium/aluminum composite capping: Performance, ecological safety and mechanisms.

There many materials were used in lake restoration to immobilize phosphorus (P) and reduce the effect of eutrophication. Among them, calcium/aluminum composite (CAC) showed a good capacity of P adsorption. However, a comprehensive of its performance, ecological safety, and the mechanism of P passivation in the aluminum-bound P (Al -P) dominated sediments under varying redox conditions remains incomplete. In the current study, both unwashed CAC (UCAC) and washed CAC (WCAC) showed good P adsorption properties, and the greatest maximum capacity for P adsorption (Qmax) reached 206.8 mg/g at pH 8.5 for UCAC. The SRP and TP in the overlying water of the uncapped sediments showed a decrease-increase-decrease trend in a sequence of transition from aerobic to anaerobic to re-aerobic stages. In contrast, the SRP and TP of the two CACs-capped sediments were maintained low. Phosphorus forms in the uncapped sediment also underwent significant changes during continuous variation of dissolved oxygen (DO) levels. In particular, the decrease in iron-bound P (Fe-P) and Al-P was significantly promoted in the anaerobic phase, and the released P was reabsorbed to form mainly Fe-P in the re-aerobic phase. The CACs-capping promoted the transformation of Fe-P to residual P (Res-P), forming a thick static layer in the surface sediment, thus significantly inhibiting sediment P release. Moreover, the CACs-capping did not induce the Al3+ leaching and significant changes of the microbial community in sediments, and their performances of P immobilization could keep stable to resist the redox variation, which promised to be a good choice for P passivation in eutrophic lake sediments dominated by Al/Fe-P. These findings also confirmed that the risk of P release from Al/Fe-P (mainly Al-P)-dominated sediments was strongly influenced by continuously changing redox conditions, and was probably enhanced by the formation of Fe-P from the resorption of the released P.

Efficacy of carboprost tromethamine combined with leonurus japonicus for prevention of postpartum hemorrhage in high-risk pregnant women: A protocol for systematic review and meta-analysis.

BACKGROUND: No well-designed and systematic evaluation of the efficacy and safety of leonurus japonicus injection (LJI) in combination with carboprost tromethamine has been found. Therefore, we undertook a meta-analysis to assess the efficacy and safety of carboprost tromethamine combined with LJI for the prevention of postpartum hemorrhage in high-risk pregnant women to provide new evidence-based medical evidence for clinical treatment. METHODS: This systematic review and meta-analysis would be performed according to Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines. The following databases including EMBASE, MEDICINE, Wanfang, China National Knowledge Infrastructure database, and Cochrane central controlled trial registries were searched by 2 reviewers from inception to July 2021. Mesh and keyword search terms were "motherwort," "Yimucao," "leonurus japonicas," "carboprost tromethamine," and "postpartum hemorrhage." Any cohort studies that assessed the efficacy and safety of carboprost tromethamine combined with LJI for the prevention of postpartum hemorrhage would be included. P < .05 was set as the level of significance. RESULTS: The review would add to the existing literature by showing compelling evidence and improved guidance in clinic settings. OSF REGISTRATION NUMBER: 10.17605/OSF.IO/2WC53.