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Aims: Few studies on early recurrence (ER) focused on patients with persistent atrial fibrillation (AF). We aimed to investigate the characteristics and clinical significance of ER in patients with persistent AF after catheter ablation (CA)., Methods: A total of 348 consecutive patients who underwent first-time CA for persistent and long-standing persistent AF between January 2019 and May 2022 were investigated., Results: About 5/348 (1.44%) patients who failed to convert to sinus rhythm after CA were excluded. A total of 110/343 (32.1%) patients had ER, in which 98 (89.1%) were persistent and 50.9% occurred in the first 24 h after CA. Compared with the patients without ER, those with ER were more likely to have late recurrence (LR) (92.7% vs. 1.7%, P  < 0.001) during a median follow-up of 13 (IQR 6-23) months. ER was the most significant independent predictor for LR (OR 120.5, 95% CI 41.5-349.8, P  < 0.001). ER as atrial flutter (AFL) had a lower risk of LR when compared with ER as AF ( P  = 0.011) and both AF and AFL ( P  = 0.003). Early intervention of the patient with ER improved the short-term outcomes ( P  < 0.001), not long-term outcomes. Only 22/251 (8.76%) patients of LR appears among those who had no recurrence in the first month., Conclusions: Patients with persistent AF may not have a blanking period but rather have a risk period. Clinical significance of the blanking period should be given differential treatment between paroxysmal AF and persistent AF., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (© 2023 Fu, Zhu, Chu, Zhong, Wang, Li, Wang, Li, Gong, Wang, Yao and Wang.)

Surface lattice oxygen is crucial to the degradation of volatile organic compounds (VOCs) over transition metal oxides according to the Mars-van Krevelen mechanism. Herein, λ-MnO 2 in situ grown on the surface of CoMn spinel was prepared by acid etching of corresponding spinel catalysts (CoMn-H x -T y ) for VOC oxidation. Experimental and relevant theoretical exploration revealed that acid etching on the CoMn spinel surface could decrease the electron cloud density around the O atom and weaken the adjacent Mn-O bond due to the fracture of the surface Co-O bond, facilitating electron transfer and subsequently the activation of surface lattice oxygen. The obtained CoMn-H1-T1 exhibited an excellent catalytic performance with a 90% acetone conversion at 149 °C, which is 42 °C lower than that of CoMn spinel. Furthermore, the partially maintained spinel structure led to better stability than pure λ-MnO 2 . In situ diffuse reflectance infrared Fourier transform spectroscopy confirmed a possible degradation pathway where adsorptive acetone converted into formate and acetate species and into CO 2 , in which the consumption of acetate was identified as the rate-limiting step. This strategy can improve the catalytic performance of metal oxides by activating surface lattice oxygen, to broaden their application in VOC oxidation.

The development of catalysts for volatile organic compound (VOC) treatment by catalytic oxidation is of great significance to improve the atmospheric environment. Size-effect and oxygen vacancy engineering are effective strategies for designing high-efficiency heterogeneous catalysts. Herein, we explored the in situ carbon-confinement-oxidation method to synthesize ultrafine MnO x nanoparticles with adequately exposed defects. They exhibited an outstanding catalytic performance with a T 90 of 167 °C for acetone oxidation, which is 73 °C lower than that of bulk MnO x (240 °C). This excellent catalytic activity was primarily ascribed to their high surface area, rich oxygen vacancies, abundant active oxygen species, and good reducibility at low temperatures. Importantly, the synthesized ultrafine MnO x exhibited impressive stability in long-term, cycling and water-resistance tests. Moreover, the possible mechanism for acetone oxidation over MnO x -NA was revealed. In this work, we not only prepared a promising material for removing VOCs but also provided a new strategy for the rational design of ultrafine nanoparticles with abundant defects.