Nitrogen-doped graphitic porous carbons (NGPCs) have been synthesized by using a zeolite-type nanoscale metal-organic framework (NMOF) as a self-sacrificing template, which simultaneously acts as both the carbon and nitrogen sources in a facile carbonization process. The NGPCs not only retain the nanopolyhedral morphology of the parent NMOF, but also possess rich nitrogen, high surface area and hierarchical porosity with well-conducting networks. The promising potential of NGPCs as metal-free electrocatalysts for oxygen reduction reactions (ORR) in fuel cells is demonstrated. Compared with commercial Pt/C, the optimized NGPC-1000-10 (carbonized at 1000 C for 10 h) catalyst exhibits comparable electrocatalytic activity via an efficient four-electron-dominant ORR process coupled with superior methanol tolerance as well as cycling stability in alkaline media. Furthermore, the controlled experiments reveal that the optimum activity of NGPC-1000-10 can be attributed to the synergetic contributions of the abundant active sites with high graphitic-N portion, high surface area and porosity, and the high degree of graphitization. Our findings suggest that solely MOF-derived heteroatom-doped carbon materials can be a promising alternative for Pt-based catalysts in fuel cells.

Ankylosing spondylitis (AS), a common type of spondyloarthropathy, is a chronic inflammatory autoimmune disease that mainly affects spine joints, causing severe, chronic pain; additionally, in more advanced cases, it can cause spine fusion. Significant progress in its pathophysiology and treatment has been achieved in the last decade. Immune cells and innate cytokines have been suggested to be crucial in the pathogenesis of AS, especially human leukocyte antigen (HLA)‑B27 and the interleukin‑23/17 axis. However, the pathogenesis of AS remains unclear. The current study reviewed the etiology and pathogenesis of AS, including genome-wide association studies and cytokine pathways. This study also summarized the current pharmaceutical and surgical treatment with a discussion of future potential therapies.