Newborn rat pups and dams were placed into an OIR model that cycled oxygen concentration between 50 % and 10 % every 24 h for 14 days , and then were placed in room air ( RA ) for an additional 4 days ( rat OIR model ) .
O B-OrganismTaxon O O O O O O O B-DiseaseOrPhenotypicFeature O O O B-ChemicalEntity O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B-OrganismTaxon B-DiseaseOrPhenotypicFeature O O O