Intraoperative dexmedetomidine reduces postoperative sleep disturbance in older adults undergoing major abdominal surgery: a single-center, randomized, double-blind, placebo-controlled trial. - Peng HP; Hu JH; Fan LP; Yang X; Liu HY; Shan XS; Liu H; Sudhan N; Ji FH; Peng K (Communications medicine, 2026)