P-Bridging Asymmetry Diatomic Catalysts Sites Drive Efficient Bifunctional Oxygen Electrocatalysis for Zinc-Air Batteries

Rechargeable zinc-air batteries (ZABs) rely on the development of high-performance bifunctional oxygen electrocatalysts to facilitate efficient oxygen reduction/evolution reactions (ORR/OER). Single-atom catalysts (SACs), characterized by their precisely defined active sites, have great potential for applications in ZABs. However, the design and architecture of atomic site electrocatalysts with both high activity and durability present significant challenges, owing to their spatial confinement and electronic states. In this study, a strategy is proposed to fabricate structurally uniform dual single-atom electrocatalyst (denoted as P-FeCo/NC) consisting of P-bridging Fe and Co bimetal atom (i.e., Fe-P-Co) decorated on N, P-co-doped carbon framework as an efficient and durable bifunctional electrocatalyst for ZABs. Experimental investigations and theoretical calculations reveal that the Fe-P-Co bridge-coupling structure enables a facile adsorption/desorption of oxygen intermediates and low activation barrier. The resultant P-FeCo/NC exhibits ultralow overpotential of 340 mV at 10 mA cm-2 for OER and high half-wave potential of 0.95 V for ORR. In addition, the application of P-FeCo/NC in rechargeable ZABs demonstrates enhanced performance with maximum power density of 115 mW cm-2 and long cyclic stability, which surpass Pt/C and RuO2 catalysts. This study provides valuable insights into the design and mechanism of atomically dispersed catalysts for energy conversion applications.

A core outcome set for clinical trials of first- and second-degree perineal tears prevention and treatment: a study protocol for a systematic review and a Delphi survey

BACKGROUND

Perineal tear is a common consequence of vaginal births affecting females globally. Even mild perineal tears could cause short- and long-term complications for females. Though many studies of interventions to prevent or treat perineal tears to minimize the consequences have been conducted, there is a significant heterogeneity in the outcomes measured and reported in existing studies, which makes meaningful comparison difficult and makes the generalizability to clinical practice challenging. Developing a core outcome set (COS) could solve these methodological concerns. In this paper, we report a protocol to develop a COS for clinical trials of mild perineal tears, which shall assist in establishing the evidence base and implementation of effective measures to reduce the incidence and minimize the consequences of mild perineal tears.

METHODS/DESIGN

The development of this COS will be guided by a study advisory group composed of obstetricians, midwives, nursing managers, service users, and methodologists. This study will include four stages: (1) a systematic research of the literature to identify outcomes reported in prior studies, (2) a semi-structured interview with key stakeholders to collect their opinions on important outcomes, (3) a panel of experts will be invited to conduct a three-round Delphi survey to prioritize these outcomes, and (4) a consensus meeting with key stakeholders to determine the list of outcomes included in the final COS.

DISCUSSION

The development of this COS will provide international standards for the outcomes to be collected and reported in all clinical trials and audits of practice, which involve prevention and treatment of first- and second-degree perineal tears for women with vaginal delivery. This will facilitate comparing and contrasting of studies and allow for combining of appropriate studies with the ultimate goal of improved perineal care for women choosing vaginal delivery.

TRIAL REGISTRATION

This study was registered in the database of Core Outcome Measures in Effectiveness Trials (COMET) on June11th, 2021 ( https://comet-initiative.org/Studies/Details/1884 ).

OsMYB3 is a R2R3-MYB gene responsible for anthocyanin biosynthesis in black rice

Black rice is a rare type of rice germplasm with various health benefits that are largely attributed to anthocyanin pigment accumulation in the pericarps. The anthocyanin biosynthesis in plant tissues is activated mainly by the MBW complexes, consisting of three types of transcription factors R2R3-MYB, bHLH, and WDR. In black rice, the bHLH and WDR components regulating anthocyanin biosynthesis in pericarps have been characterized, while the R2R3-MYB factor remains unknown. By examining the expression correlation between all putative rice MYB genes and anthocyanin biosynthesis-related genes based on transcriptome data of pericarps in combination with further molecular and genetic analysis, we proved that OsMYB3 (LOC_Os03g29614) was the determinant R2R3-MYB gene for anthocyanin biosynthesis in rice pericarps. The expression level of OsMYB3 in pericarps of black rice was significantly higher than that of white rice. The knockout of OsMYB3 in a black rice variety caused significant downregulation of 19 anthocyanin metabolites and many other flavonoids in grains. Our research deepens the understanding of regulatory system for anthocyanin biosynthesis in rice pericarps and provides implications for breeding black rice varieties with high anthocyanin level.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11032-021-01244-x.