Design of MoS2 edge-anchored single-atom catalysts for propane dehydrogenation driven by DFT and microkinetic modeling.

The design of efficient catalysts for direct propane dehydrogenation (PDH) to inhibit coke formation and deactivation of traditional Pt-based catalysts are challenging tasks. Herein, by exploiting the unique geometric feature and tunability of single atom catalysts (SACs), a wide range of 3d-5d transition metals anchored on the MoS2 edge in the single atom form (TM1-S4/edge) are comprehensively investigated for the PDH application by first-principles calculations, ab initio molecular dynamics (AIMD) simulations and microkinetic modeling. Five criteria are assessed in terms of the feasibility of preparation, practical stability, feasibility of recovery after air oxidation, activity and selectivity. We identified Ru1-S4/edge SAC as the most promising candidate with activity six times higher than that of the conventional Pt(111) catalyst. Interestingly, AIMD simulations show that the motif region of the highly reactive TM1-S4/edge SACs (such as Ru, Os, Rh, and Ir) exhibits a dynamic change, with a TM-coordinated S atom tending to flutter at reaction temperatures and return to its initial position when the species is adsorbed on TMs, thereby affecting the PDH activities. In addition to identifying the potential PDH catalyst from a practical application point of view, we believe that this study also provides a comprehensive picture for the theoretical screening of low-coordination single-atom catalysts.

Combined microscope-endoscopy resection of petrous bone cholesteatoma with temporary facial nerve transposition versus nontransposition.

PURPOSE: The narrow supralabyrinthine space affects surgical procedures. To study the effect of temporary transposition of geniculate ganglion of facial nerve versus nontransposition on lesion recurrence and facial nerve function in patients with petrous bone cholesteatoma. METHODS: A total of 18 patients with petrous bone cholesteatoma involving the facial nerve were treated in our hospital from November 2016 to March 2023. The main surgical method is the extended supralabyrinthine approach assisted by a microscope and an endoscope. We collected and retrospectively analyzed their medical records. RESULTS: Temporary facial nerve transposition was performed in five patients, and nontransposition was performed in 13 patients. Cholesteatoma recurred in three patients with facial nerve nontransposition, whereas none in patients with facial nerve transposition. In this study, except for one case with a second operation, postoperative facial paralysis in other cases was improved to varying degrees, and there was no significant difference between the two groups. CONCLUSION: Temporary transposition of geniculate ganglion of facial nerve will not affect the postoperative nerve function of patients and can reduce the possibility of cholesteatoma recurrence of the petrous bone.

[Study on the management of granulation during surgery for congenital preauricular fistula infection stage].

Objective:To investigate the management of granulation tissue during surgery for infected congenital preauricular fistula and to assess the surgical outcomes. Methods:To summarize the surgical methods and the treatment of granulation methods in 140 cases of congenital preauricular fistula during the period of infection treated in our department from January 2018 to September 2022. The study divided patients into an observation group （79 patients） undergoing fistulectomy without granulation treatment, and a control group （61 patients） where fistulectomy and granulation resection were performed concurrently.. After six months of follow-up, the wound healing, recurrence rates, and the aesthetic assessment of granulation healing were evaluated using the Stony Brook Scar Evaluation Scale（SBSES）. Results:The two surgical approaches were applied to a total of 140 patients with infected congenital preauricular fistula. There was no statistical difference in wound healing and recurrence rates between the observation group and the control group. However, the observation group exhibited smaller scars. Conclusion:In cases of infected congenital preauricular fistula, surgical removal without excising granulation tissue is feasible, leading to effective healing and lesser scar formation.