MuRF-1 and Atrogin-1 Protein Expression and Quadriceps Fiber Size and Muscle Mass in Stable Patients with COPD - Natanek,SA; Riddoch-Contreras,J; Marsh,GS; Hopkinson,NS; Moxham,J; Man,WD-C; Kemp,PR; Polkey,MI (Copd-Journal of Chronic Obstructive Pulmonary Disease, 2013)