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INTRODUCTION: Peptic ulcer disease (PUD) and postprocedural artificial ulcers are common ulcer disease. For them, proton pump inhibitor (PPI) and potassium-competitive acid blocker (P-CAB) are commonly used in clinical practice. PPI requires acid, time, and multiple doses, but P-CAB has fewer limitations. We compared the efficacy, safety, and prevention of PPI and P-CAB in PUD or artificial ulcer. METHODS: We searched PubMed, ClinicalTrials.gov , Embase, Cochrane Library, and Web of Science databases for all studies. All eligible randomized controlled trials up to August 5, 2023, were included. Healing rates, shrinking rates, treatment-emergent adverse events rates, and recurrence rates were measured. Risk of bias, sensitivity analyses, and heterogeneity were also performed. RESULTS: Twenty researches that were selected from 926 screening studies and in total 6,551 participants were included. The risk ratio (RR) of healing rate with P-CABs vs PPIs of PUD at 4 weeks was RR 1.01 (95% confidence interval 0.98-1.04). In addition, the healing rate distinction of artificial peptic ulcer was RR 1.04 (0.89-1.22), and the shrinking rate was mean difference 0.10 (-1.30-1.51). The result of treatment-emergent adverse event rate of PUD was RR 1.11 (0.91-1.35), and the delayed bleeding rate of artificial ulcer was RR 0.35 (0.16-0.80). The RR for recurrence rate of drug-related ulcers was 0.45 (0.25-0.81). DISCUSSION: P-CAB is noninferior in healing artificial ulcer and PUD, also the incidence of treatment-emergent adverse events. But, there may be a statistical advantage in holding back delayed bleeding and preventing drug-induced ulcers. More standardized experiments are needed for further applications and more precise conclusions.
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Graphene supported electrocatalysts have demonstrated remarkable catalytic performance for oxygen reduction reaction (ORR). However, their durability and cycling performance are greatly limited by Oswald ripening of platinum (Pt) and graphene support corrosion. Moreover, comprehensive studies on the mechanisms of catalysts degradation under 0.6-1.6 V versus RHE (Reversible Hydrogen Electrode) is still lacking. Herein, degradation mechanisms triggered by different defects on graphene supports are investigated by two cycling protocols. In the start-up/shutdown cycling (1.0-1.6 V vs. RHE), carbon oxidation reaction (COR) leads to shedding or swarm-like aggregation of Pt nanoparticles (NPs). Theoretical simulation results show that the expansion of vacancy defects promotes reaction kinetics of the decisive step in COR, reducing its reaction overpotential. While under the load cycling (0.6-1.0 V vs. RHE), oxygen containing defects lead to an elevated content of Pt in its oxidation state which intensifies Oswald ripening of Pt. The presence of vacancy defects can enhance the transfer of electrons from graphene to the Pt surface, reducing the d-band center of Pt and making it more difficult for the oxidation state of platinum to form in the cycling. This work will provide comprehensive understanding on Pt/Graphene catalysts degradation mechanisms.
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The pore structure of carbon anodes plays a crucial role in enhancing the sodium storage capacity. Designing more confined pores in carbon anodes is accepted as an effective strategy. However, current design strategies for confined pores in carbon anodes fail to achieve both high capacity and initial Coulombic efficiency (ICE) simultaneously. Herein, we develop a strategy for utilizing the repeated impregnation and precarbonization method of liquid pitch to regulate the pore structure of the activated carbon (AC) material. Driven by capillary coalescence, the pitch is impregnated into the pores of AC, which reduces the specific surface area of the material. During the carbonization process, numerous pores with diameters less than 1 nm are formed, resulting in a high capacity and improved ICE of the carbon anode. Moreover, the ordered carbon layers derived from the liquid pitch also enhance the electrical conductivity, thereby improving the rate capability of as-obtained carbon anodes. This enables the fabricated material (XA-4T-1300) to have a high ICE of 91.1% and a capacity of 383.0 mA h g-1 at 30 mA g-1. The capacity retention is 95.5% after 300 cycles at 1 A g-1. This study proposes a practical approach to adjust the microcrystalline and pore structures to enhance the performance of sodium-ion storage in materials.