Transitional Fetal Circulation: A Comprehensive Review of Physiological Adaptation, Failure, and Neonatal Outcomes - Cureus

Sarcopenia is increasingly recognized as a multidimensional syndrome reflecting impaired physiological reserve rather than isolated skeletal muscle loss. Although numerous circulating biomarkers have been associated with sarcopenia and adverse orthopaedic outcomes, their biological significance varies according to the underlying clinical context. This narrative review integrates current evidence on circulating biomarkers of sarcopenia and physiological reserve across elective total hip and knee arthroplasty, fragility hip fracture, community-dwelling older adults, and medically complex populations. The available evidence demonstrates that sarcopenic phenotypes differ substantially between these populations, with predominantly disuse-related muscle deterioration in elective arthroplasty, frailty-associated sarcopenia after hip fracture, and metabolically driven muscle loss in chronic systemic diseases. Nutritional (albumin, geriatric nutritional risk index), inflammatory (C-reactive protein (CRP), neutrophil-to-lymphocyte ratio, CRP-to-albumin ratio), metabolic (aspartate aminotransferase-to-alanine aminotransferase ratio, glucose-to-albumin ratio), endocrine (vitamin D, insulin-lik

We’re sharing this article early to provide faster access to peer-reviewed, accepted research. It is citable and carries a permanent DOI. This version is subject to further edits and will be replaced automatically by the final Version of Record. All legal disclaimers apply. AbstractMultiplexed sensor arrays expand biomedical interfaces by allowing independently recoverable sensing sources to share limited transmission, addressing, readout, acquisition, and computational resources. This Review compares time-, frequency-, spatial-, optical-, code-, and hybrid-multiplexing through a requirement–resource framework. We examine how signal integrity, front-end electronics, calibration, materials, mechanics, power, and data handling constrain source-specific recovery and outline architecture-selection principles for reliable physiological sensing and bidirectional biointerfaces.