controlled study Article 72 nonhuman 56 scanning electron microscopy 47 transmission electron microscopy 36 human 32 chemistry 31 unclassified drug 27 Humans 25 animal experiment 19 particle size 19 Animals 18 X ray diffraction 18 animal 18 animal tissue 17 drug effect 17 metabolism 16 in vitro study 15 surface property 15 Fourier transform infrared spectroscopy 14 animal model 14 male 14 ultrastructure 14 Microscopy, Electron, Scanning 13 antiinfective agent 13 human cell 13 mouse 13 antibacterial activity 12 minimum inhibitory concentration 12 procedures 12