RESUMEN
Superconductivity in a highly correlated kagome system has been theoretically proposed for years (refs. 1-5), yet the experimental realization is hard to achieve6,7. The recently discovered vanadium-based kagome materials8, which exhibit both superconductivity9-11 and charge-density-wave orders12-14, are nonmagnetic8,9 and weakly correlated15,16. Thus these materials are unlikely to host the exotic superconductivity theoretically proposed. Here we report the discovery of a chromium-based kagome metal, CsCr3Sb5, which is contrastingly featured with strong electron correlations, frustrated magnetism and characteristic flat bands close to the Fermi level. Under ambient pressure, this kagome metal undergoes a concurrent structural and magnetic phase transition at 55 K, with a stripe-like 4a0 structural modulation. At high pressure, the phase transition evolves into two transitions, possibly associated with charge-density-wave and antiferromagnetic spin-density-wave orderings. These density-wave-like orders are gradually suppressed with pressure and, remarkably, a superconducting dome emerges at 3.65-8.0 GPa. The maximum of the superconducting transition temperature, Tcmax = 6.4 K, appears when the density-wave-like orders are completely suppressed at 4.2 GPa, and the normal state exhibits a non-Fermi-liquid behaviour, reminiscent of unconventional superconductivity and quantum criticality in iron-based superconductors17,18. Our work offers an unprecedented platform for investigating superconductivity in correlated kagome systems.
RESUMEN
BACKGROUND: Transcolonic endoscopic appendectomy (TEA) is rapidly evolving and has been reported as a minimally invasive alternative to appendectomy. We aimed to characterize the feasibility and safety of a novel unassisted single-channel TEA. METHOD: We retrospectively investigated 23 patients with appendicitis or appendiceal lesions who underwent TEA from February 2016 to December 2022. We collected clinicopathological characteristics, procedurerelated parameters, and followup data and analyzed the impact of previous abdominal surgery and traction technique. RESULTS: The mean age was 56.0 years. Of the 23 patients with appendiceal lesions, fourteen patients underwent TEA and nine underwent traction-assisted TEA (T-TEA). Eight patients (34.8%) had previous abdominal surgery. The En bloc resection rate was 95.7%. The mean procedure duration was 91.1 ± 45.5 min, and the mean wound closure time was 29.4 ± 18.6 min. The wounds after endoscopic appendectomy were closed with clips (21.7%) or a combination of clip closure and endoloop reinforcement (78.3%), and the median number of clips was 7 (range, 3-15). Three patients (13.0%) experienced major adverse events, including two delayed perforations (laparoscopic surgery) and one infection (salvage endoscopic suture). During a median follow-up of 23 months, no residual or recurrent lesions were observed, and no recurrence of abdominal pain occurred. There were no significant differences between TEA and T-TEA groups and between patients with and without abdominal surgery groups in each factor. CONCLUSION: Unassisted single-channel TEA for patients with appendiceal lesions has favorable short- and long-term outcomes. TEA can safely and effectively treat appendiceal disease in appropriately selected cases.