Activity Promotion of Core and Shell in Multifunctional Core-Shell Co2 P@NC Electrocatalyst by Secondary Metal Doping for Water Electrolysis and Zn-Air Batteries.

Developing cost-efficient multifunctional electrocatalysts is highly critical for the integrated electrochemical energy-conversion systems such as water electrolysis based on hydrogen/oxygen evolution reactions (HER/OER) and metal-air batteries based on OER/oxygen reduction reactions (ORR). The core-shell structured materials with transition metal phosphide as the core and nitrogen-doped carbon (NC) as the shell have been known as promising HER electrocatalysts. However, their oxygen-related electrocatalytic activities still remain unsatisfactory, which severely limits their further applications. Herein an effective strategy to improve the core and shell performances of core-shell Co2 P@NC electrocatalysts through secondary metal (e.g., Fe, Ni, Mo, Al, Mn) doping (termed M-Co2 P@M-N-C) is reported. The as-synthesized M-Co2 P@M-N-C electrocatalysts show multifunctional HER/OER/ORR activities and good integrated capabilities for overall water splitting and Zn-air batteries. Among the M-Co2 P@M-N-C catalysts, Fe-Co2 P@Fe-N-C electrocatalyst exhibits the best catalytic activities, which is closely related to the configuration of highly active species (Fe-doping Co2 P core and Fe-N-C shell) and their subtle synergy, and a stable carbon shell for outstanding durability. Combination of electrochemical-based in situ Fourier transform infrared spectroscopy with extensive experimental investigation provides deep insights into the origin of the activity and the underlying electrocatalytic mechanisms at the molecular level.

[Modified Bethesda, modified Nijmegen and blank assays for coagulation factor VIII inhibitor detection and factors affecting the results].

OBJECTIVE: To evaluate the clinical value of modified Bethesda assay, modified Nijmegen assay and blank assay for detection of coagulation factor VIII (FVIII) inhibitors in patients with hemophilia A and analyze the factors that affect FVIII inhibitor detection. METHODS: The levels of FVIII inhibitors in 257 patients with hemophilia A were detected using modified Bethesda assay, modified Nijmegen assay and blank assay (in which the buffer or FVIII-deficient plasma in the control mixture was replaced by deionized water). The 3 methods were compared for positivity rates and FVIII inhibitor titers based on the positive cut-off value of FVIII inhibitors ≥0.60 BU/mL. RESULTS: The positive rates of modified Bethesda assay, modified Nijmegen assay and blank assay were 79.38%, 85.21% and 72.37%, respectively. A strong correlation was found between the results by modified Bethesda assay and modified Nijmegen assay (r=0.996, P<0.001), and FVIII inhibitor titers (P<0.001) but not the positive rates (P=0.105) detected by the two methods differed significantly. The correlation coefficients between modified Nijmegen assay and blank assay was 0.994 (P<0.001), and a significant difference was found in FVIII inhibitor titers (P<0.001) but not the positivity rates (P=0.079) detected by the two methods. The correlation coefficient between modified Nijmegen assay and blank assay was 0.994 (r=0.994), and the two methods yielded significantly different FVIII inhibitor titers and positivity rates (P=0.001). CONCLUSION: The modified Bethesda assay has a lower sensitivity than modified Nijmegen assay but has a higher sensitivity than blank assay. The consistency level of coagulation factors in the reaction system and stable buffer system are important factors that affect FVIII-inhibitor detection.