priority journal article 98 controlled study 80 nonhuman 80 Animals 52 male 42 unclassified drug 38 Male 36 animal experiment 34 Article 32 human 32 animal tissue 30 cell density 28 Humans 26 Female 24 animal cell 24 female 24 Density functional theory 22 animal model 22 density functional theory 22 rat 22 Rats 20 metabolism 20 animal 18 chemical structure 18 Centrifugation, Density Gradient 16 optical density 16 Kinetics 14 Mice 14 Models, Molecular 14