Shared Metabolic–Proteinopathy Axis in Alzheimer's Disease and Parkinson's Disease: Evidence for a Convergent but Not Identical Disease Spectrum - Shun‐yu Yao; Miao‐qiao Du; Lan‐xin Lin; Xu‐hui Kang; Dai‐yi Jiang; Yong Peng (AGING MEDICINE, 2026)