title: Correlation between amniotic fluid lecithin-sphingomyelin (L/S) ratio and optical density measured after centrifugation at varying forces.
mesh_terms: D000653:Amniotic Fluid / Q000032:analysis*; D002499:Centrifugation, Density Gradient; D005260:Female; D005325:Fetal Organ Maturity; D006801:Humans; D008168:Lung / Q000196:embryology; D055095:Optics and Photonics; D010713:Phosphatidylcholines / Q000032:analysis*; D013109:Sphingomyelins / Q000032:analysis*
chemical_list: D010713:Phosphatidylcholines; D013109:Sphingomyelins