Chemistry 129 Organic chemistry 119 QD Chemistry 93 chemistry 92 Research & information: general 85 Article 40 human 40 Humans 37 Technology: general issues 37 Research and information: general 30 Analytical chemistry 29 Spectrum analysis, spectrochemistry, mass spectrometry 27 nonhuman 24 procedures 23 controlled study 22 Industrial chemistry and chemical engineering 21 metabolism 21 Animals 20 animal 19 Inorganic chemistry 17 Physical chemistry 16 Biology, life sciences 15 Polymer chemistry 15 genetics 15 Biochemistry 14 Environmental science, engineering & technology 13 male 13 unclassified drug 13 Male 12 pH 12