pH 280 article 216 Hydrogen-Ion Concentration 139 nonhuman 115 priority journal 91 controlled study 80 chemistry 70 metabolism 66 Kinetics 60 pH effects 60 unclassified drug 60 Animals 41 animal 41 Animal 40 Article 39 kinetics 39 enzyme activity 38 temperature 33 Adsorption 32 Rats 31 Support, U.S. Gov't, P.H.S. 30 Oxidation-Reduction 29 Support, Non-U.S. Gov't 28 chemical structure 28 rat 28 enzymology 27 water 27 Argentina 26 Temperature 26 Water 26