Rapid Formation of Epitaxial Oxygen Evolution Reaction Catalysts on Dendrites with High Catalytic Activity and Stability.

Oxygen evolution reaction is an essential but kinetically sluggish step in many energy storage and conversion processes and therefore is in pursuit of highly efficient and stable catalysts. Although nanosized transition-metal-based oxides/hydroxides exhibit high catalytic activity toward the oxygen evolution reaction (OER), many of them suffer from low stability at an anode current density in industrial scale. Herein, by combining a rapid epitaxial formation method with dynamic bubble-templated electrodeposition, we successfully developed single crystalline NiFeCu oxide catalysts with a hierarchical porous structure. It was found that the structure can facilitate fast electron transportation for the catalysts and retard the diffusion of the O atoms to the inner metallic current collector. The hierarchical pores inherited from the hydrogen bubble templates built ideal channels for the massive and rapid release of oxygen bubbles. As a consequence, the NiFeCu oxides catalyzed the OER more efficiently and steadily than the commercial RuO2 catalyst at an anode current density in industrial scale (300 mA/cm2). This work, by resolving the durability concerns for nanosized oxides, offers a series of highly efficient and stable catalysts for OER and a structure building strategy to boost the catalytic activity and stability for nonconductive catalysts.

Entropy-Stabilized Multicomponent Porous Spinel Nanowires of NiFeXO4 (X = Fe, Ni, Al, Mo, Co, Cr) for Efficient and Durable Electrocatalytic Oxygen Evolution Reaction in Alkaline Medium.

Cost-effective electrochemical water splitting technology hinges on the development of efficient and durable catalysts for oxygen evolution reaction (OER). Spinel oxides (formula: AxB3-xO4) are structurally stable for real applications. Much effort has been devoted to improving the catalytic activity. Here, we report a eutectic dealloying strategy to activate the porous spinel NiFe2O4 nanowires with up to four metal cation substitutions. As-obtained spinel NiFeXO4 (X = Fe, Ni, Al, Mo, Co, Cr) delivers a benchmark current density of 10 mA·cm-2 at an overpotential of only 195 mV, outperforming most spinel phase OER electrocatalysts and comparable to the state-of-the-art NiFe hydroxides. It is stable for over 115 h of electrolysis. Aberration-corrected transmission electron microscopy, high-resolution electron energy loss spectroscopy, and atomic-scale strain mappings reveal that the multivalent cation substitutions result in substantial lattice distortion and significant electronic coupling of metal 3d and O 2p orbitals for increased covalency. Further theoretical calculations suggest that the NiFeXO4 are stabilized by the high configurational entropy, and their synergy favors the absorption of H2O molecules and lowers the adsorption energy barrier of the OOH* intermediate. The improved intrinsic activity together with the highly nanoporous structures contribute to the appealing apparent catalytic performances. The work demonstrates an effective approach for the synthesis of stable multicomponent spinel oxides and highlights the effectiveness of the multication substitution strategy for producing highly durable and active spinel catalysts, which meet multiplexed structure and superior property requirements in practical applications.

Meta-analysis of safety of human purified Vero cell rabies vaccine after exposure / 中国生物制品学杂志

@#Objective To evaluate the safety of human purified Vero cell rabies vaccine(PVRV)after exposure in China by Meta-analysis.Methods With rabies,vaccine and safety as key words,a systematic search was performed in PubMed,EMBASE,Cochrane and China National Knowledge Infrastructure(CNKI),supplemented by manual retrieval.A Meta-analysis was performed to analyze the incidence of adverse events of two immunization regimens Zagreb and Essen using Review Manager 5.4 software after literature screening and data extraction according to the inclusion and exclusion criteria.Results A total of 12 studies were included,of which 7 were prospective studies and 5 were retrospective studies.Most included in the studies showed a low risk of bias.The incidence of adverse events in Zagreb regimen was significantly higher than that in Essen regimen[relative risk(RR)= 1.01,95% CI = 0.90 ～ 1.14;I2= 73.00%,P<0.05],but there was a high degree of heterogeneity.The incidence of fever,pain and induration in Zagreb regimen was significantly higher than that in Essen regimen(RR = 1.14,0.92 and 0.86,95% CI = 0.82 ～ 1.60,0.73 ～ 1.14 and 0.29 ～ 2.51;I2= 73.00%,P<0.05],but there was a high degree of heterogeneity.The incidence of fever,pain and induration in Zagreb regimen was significantly higher than that in Essen regimen(RR = 1.14,0.92 and 0.86,95% CI = 0.82 ～ 1.60,0.73 ～ 1.14 and 0.29 ～ 2.51;I2= 81%,65% and 92%,respectively,P<0.01).Conclusion Two regimens of PVRV vaccination after exposure showed good safety.However,when adopting Zagreb regimen,attention should be paid to the physical conditions of children and the elderly with relatively poor immunity to avoid adverse events.

Synergistic Hybrid Electrocatalysts of Platinum Alloy and Single-Atom Platinum for an Efficient and Durable Oxygen Reduction Reaction.

Pt single-atom materials possess an ideal atom economy but suffer from limited intrinsic activity and side reaction of producing H2O2 in catalyzing the oxygen reduction reaction (ORR); platinum alloys have higher intrinsic activity but weak stability. Here, we demonstrate that anchoring platinum alloys on single-atom Pt-decorated carbon (Pt-SAC) surmounts their inherent deficiencies, thereby enabling a complete four-electron ORR pathway catalysis with high efficiency and durability. Pt3Co@Pt-SAC demonstrates an exceptional mass and specific activities 1 order of magnitude higher than those of commercial Pt/C. They are durable throughout 50000 cycles, showing only a 10 mV decay in half-wave potential. An in situ Raman analysis and theoretical calculations reveal that Pt3Co core nanocrystals modulate electron structures of the adjacent Pt single atoms to facilitate the intermediate absorption for fast kinetics. The superior durability is attributed to the shielding effect of the Pt-SAC coating, which significantly mitigates the dissolution of Pt3Co cores. The hybridizing strategy might promote the development of highly active and durable ORR catalysts.

Safety and immunogenicity of human rabies vaccine for the Chinese population after PEP: A systematic review and meta-analysis.

AIM: To evaluate the safety and immunogenicity of rabies vaccine for human use after post-exposure in China. METHODS: A systematic search was performed from PubMed, EMBASE, CNKI and Cochrane Library database, supplemented by manual retrieval. According to the inclusion and exclusion criteria, a meta-analysis was performed using Stata 16.0 software after independent literature screening, data extraction and quality assessment by two evaluators. RESULTS: A total of 32 studies were included. It was found that rabies vaccination after PEP could induce the body to produce sufficient RVNA. Both Essen and Zagreb regimens showed good immunogenicity, with no significant difference in systemic events and local events after PEP, but a relatively high incidence of local and systemic events after PEP under the Zagreb regimen. CONCLUSION: For the Chinese population, rabies vaccination after PEP has shown relatively a good immune efficacy and acceptable safety for preventing human rabies. The survey also found that the Zagreb regimen was comparable to the Essen regimen in terms of rabies prophylaxis with an acceptable safety profile.

Safety and immunogenicity of a quadrivalent inactivated subunit non-adjuvanted influenza vaccine: A randomized, double-blind, active-controlled phase 1 clinical trial.

Quadrivalent influenza inactivated vaccine (IIV4) is more likely to provide wider protection against yearly circulating influenza viruses than trivalent inactivated influenza vaccine (IIV3). In this study, a total of 320 participants were allocated to four age cohorts (6-35 months, 3-8 years, 9-17 years, and ≥ 18 years; 80 participants/cohort) according to their actual date of birth. Participants in each cohort were randomly assigned to two groups to receive intramuscular injection of the trial vaccine or the comparative vaccine in a one-dose (3-8 years, 9-17 years,and ≥ 18 years) schedule on day 0 or two-dose (6-35 months cohort) schedule on day 0 and 28. The first objective is to evaluate the safety and immunogenicity of the full-dose subunit non-adjuvanted IIV4 (FD-subunit NAIIV4) we developed versus an active-control, China-licensed split-virion NAIIV4, in people ≥ 3 years. The second objective is to evaluate the safety and immunogenicity of FD-subunit NAIIV4 versus the half-dose (HD-subunit NAIIV4) in toddlers aged 6-35 months. Results showed that all adverse reactions noted were rare, mild, and self-limited. In ≥ 3 years cohorts, systemic adverse reactions in FD-subunit NAIIV4 groups were less than the active control split-virion NAIIV4 groups ([Systemic adverse reaction rates (95%CI)], 15.0 (8.6-21.4) versus 19.2(12.1-26.2), p = 0.391). The overall seroprotection efficacy after vaccination were comparable between FD-subunit NAIIV4 and the active control split-virion NAIIV4([Seroprotection rates (95%CI)], H1N1, 99.2(81.3-100.0) versus 94.9(90.9-98.9), p = 0.117; H3N2, 81.7(74.7-88.6) versus 82.1(75.1-89.0), p = 0.939; BV, 75.8(68.2-83.5) versus 74.4(66.4-82.3), p = 0.793; BY, 94.2(90.0-98.4) versus 92.3(87.5-97.1), p = 0.568). Additionally, FD-subunit NAIIV4 has comparable safety and better seroprotection versus that of the half-dose in 6-35 months toddlers groups ([Total adverse reaction rates (95%CI)], 37.5(18.5-56.5) versus 47.5(26.1-68.9), p = 0.366) ([Seroprotection rates (95%CI)], H1N1, 85(56.4-100.0) versus 75.7(47.6-100.0), p = 0.117; H3N2, 50(28.1-71.9) versus 29.7(12.2-47.3), p = 0.070; BV, 75(48.2-100.0) versus 29.7(12.2-47.3), p < 0.001; BY, 75(48.2-100.0) versus 56.8(32.5-81.0), p = 0.091). As a result, the FD-subunit NAIIV4 we developed is safe and effective to provide broader and adequate protection against the circulating influenza viruses during 2018-2019, which could be an essential component of the global preventive strategy for influenza pandemic.

Atomic Ni and Cu co-anchored 3D nanoporous graphene as an efficient oxygen reduction electrocatalyst for zinc-air batteries.

Highly active, cost-effective and durable electrocatalysts for the oxygen reduction reaction (ORR) are critically important for renewable energy conversion and storage. Here we report a 3D bicontinuous nitrogen doped nanoporous graphene electrocatalyst co-anchoring with atomically dispersed nickel and copper atoms ((Ni,Cu)-NG) as a highly active single-atom ORR catalyst, fabricated by the combination of chemical vapor deposition and high temperature gas transportation. The resultant (Ni,Cu)-NG exhibits an exceptional ORR activity in alkaline electrolytes, comparable to the Pt-based benchmarks, from the synergistic effect of the CuNx and NiNx complexes. Endowed with high catalytic activity and outstanding durability under harsh electrochemical environments, rechargeable zinc-air batteries using (Ni,Cu)-NG as the cathodes show excellent energy efficiency (voltage gap of 0.74 V), large power density (150.6 mW cm-2 at 250 mA cm-2) and high cycling stability (>500 discharge-charge cycles at 10 mA cm-2). This study may pave an efficient avenue for designing highly durable single-atom ORR catalysts for metal-air batteries.

Rapid Fabrication of Ni/NiO@CoFe Layered Double Hydroxide Hierarchical Nanostructures by Femtosecond Laser Ablation and Electrodeposition for Efficient Overall Water Splitting.

The development of simple and effective methods for the rapid preparation of electrocatalysts for overall water splitting from earth-abundant elements is an important and challenging task. A facile and ultrafast two-step method was developed to prepare a Ni/NiO@CoFe layered double hydroxide hierarchical nanostructure (NCF) within a few minutes by femtosecond laser ablation and electrodeposition. In 1 m KOH solution, the optimized NCF catalysts show a low overpotential of 230 mV for the oxygen evolution reaction (OER) at a current density of 10 mA cm-2 with a low Tafel slope of 34.3 mV dec-1 , indicating fast and efficient OER kinetics. Owing to the synergistic effect between NiO and CoFe layered double hydroxide, the hydrogen evolution reaction performance of the NCF was also improved. The synthesized electrocatalysts were further utilized in overall water splitting with a potential of only 1.56 V at a current density of 10 mA cm-2 and excellent durability, better than that of the commercial RuO2 (+)//Pt/C(-) system. The present work provides new insights on the rapid and facile preparation of efficient electrocatalysts for overall water splitting on a large scale.

One-pot synthesis of CuPt nanodendrites with enhanced activity towards methanol oxidation reaction.

CuPt nanodendrites have special electrocatalytic performance due to their unique morphologies and structures. In this work, we report a facile and one-pot synthesis of highly branched and dispersed CuPt nanodendrites with a size of about 22 nm and Pt/Cu ratio of 2 : 1. X-ray photoelectron spectra indicate a Pt-rich surface of the prepared CuPt nanodendrites. The combination of a highly branched structure with a Pt-rich shell would be very beneficial for catalytic properties, which was confirmed by electrochemical tests towards MOR. A systematic study on morphology evolution of the products and understanding of their growth mechanism was carried out using the effects of reaction time and reducing agents.