Technology: general issues 284 Research & information: general 181 History of engineering and technology 178 TP Chemical technology 177 TA Engineering (General). Civil engineering (General) 160 human 156 Humans 131 TJ Mechanical engineering and machinery 112 Biology, life sciences 98 Article 81 Materials science 81 TK Electrical engineering. Electronics Nuclear engineering 71 Research and information: general 66 Chemistry 63 History of engineering & technology 63 Sustainable development 59 chemistry 57 Animals 56 article 56 female 55 animal 54 controlled study 54 male 54 nonhuman 45 Physics 42 adult 42 physiology 40 Female 39 Male 39 procedures 39