| 1 | Ecology | 842 | 68.0K | 6 | 6 |
| 2 | Pollution | 540 | 45.8K | 4 | 3 |
| 3 | Biology | 308 | 42.8K | 36 | 35 |
| 4 | Environment | 328 | 37.8K | 11 | 7 |
| 5 | Science | 250 | 33.5K | 39 | 35 |
| 6 | Biodiversity conservation | 230 | 29.7K | 2 | 2 |
| 7 | Climate change | 151 | 25.0K | 2 | 1 |
| 7 | Eutrophication | 151 | 25.0K | 2 | 1 |
| 9 | Physics | 95 | 22.8K | 93 | 46 |
| 10 | environmental pollution | 304 | 16.0K | 5 | 4 |
| 11 | Natural history | 56 | 15.3K | 32 | 48 |
| 12 | Agricultural Ecology | 128 | 13.1K | 1 | 1 |
| 13 | Agriculture | 128 | 12.7K | 6 | 2 |
| 14 | Environmental Health | 194 | 12.1K | 20 | 18 |
| 15 | Geophysics | 146 | 11.1K | 46 | 24 |
| 16 | Environmental Engineering | 125 | 9.3K | 11 | 7 |
| 17 | Environmental Policy | 102 | 9.2K | 8 | 5 |
| 18 | Chemistry | 59 | 8.9K | 820 | 201 |
| 19 | Hydrology | 153 | 8.5K | 7 | 5 |
| 20 | Microbial Ecology | 71 | 8.1K | 17 | 11 |
| 21 | Meteorology | 112 | 8.0K | 9 | 8 |
| 22 | Atmospheric Physics | 108 | 7.5K | 16 | 9 |
| 23 | Biodiversity | 157 | 7.3K | 6 | 5 |
| 24 | Microbiology | 69 | 7.2K | 82 | 49 |
| 25 | Atmospheric Chemistry | 87 | 7.1K | 6 | 5 |
| 26 | Environmental monitoring | 95 | 7.0K | 20 | 14 |
| 27 | Water | 81 | 6.9K | 17 | 11 |
| 28 | Evolution | 70 | 6.9K | 14 | 8 |
| 29 | Wildlife conservation | 103 | 6.3K | 3 | 1 |
| 30 | Research | 117 | 5.9K | 63 | 58 |
| 31 | Medicine | 107 | 5.4K | 115 | 143 |
| 32 | Plant Ecology | 99 | 5.4K | 10 | 12 |
| 33 | Botany | 75 | 4.9K | 126 | 87 |
| 34 | sanitation | 75 | 4.5K | 5 | 7 |
| 35 | Technology | 48 | 4.4K | 56 | 24 |
| 36 | environmental protection | 45 | 4.3K | 21 | 11 |
| 37 | ecosystem | 73 | 4.3K | 4 | 4 |
| 38 | pollutants | 120 | 4.2K | 4 | 5 |
| 38 | Environmental pollutants | 120 | 4.2K | 4 | 5 |
| 40 | water supply | 49 | 4.1K | 32 | 21 |
| 41 | soil microbiology | 62 | 4.1K | 8 | 8 |
| 42 | Environmental Management | 101 | 4.0K | 8 | 7 |
| 43 | Earth Sciences | 66 | 3.8K | 14 | 10 |
| 44 | Biotechnology | 32 | 3.7K | 151 | 65 |
| 45 | Environmental Microbiology | 24 | 3.6K | 20 | 9 |
| 46 | Environmental Law | 26 | 3.6K | 16 | 7 |
| 47 | Biogeography | 49 | 3.6K | 10 | 5 |
| 48 | Planets | 39 | 3.6K | 134 | 48 |
| 49 | Animal ecology | 62 | 3.5K | 8 | 5 |
| 50 | Molecular Biology | 59 | 3.5K | 264 | 293 |
| 51 | Zoology | 64 | 3.4K | 17 | 8 |
| 52 | Biochemistry | 56 | 3.4K | 247 | 200 |
| 53 | Marine Biology | 82 | 3.4K | 12 | 9 |
| 54 | biological evolution | 26 | 3.3K | 36 | 19 |
| 55 | freshwater biology | 59 | 3.2K | 3 | 3 |
| 56 | Water pollution | 53 | 3.2K | 12 | 11 |
| 57 | Biogeochemistry | 86 | 3.1K | 4 | 7 |
| 58 | Climatology | 40 | 3.1K | 25 | 17 |
| 59 | Entomology | 67 | 3.0K | 16 | 7 |
| 60 | Toxicology | 68 | 3.0K | 43 | 34 |
| 61 | Soil biology | 52 | 3.0K | 5 | 5 |
| 62 | Environmental Chemistry | 59 | 2.8K | 7 | 12 |
| 63 | Molecular Genetics | 39 | 2.7K | 49 | 55 |
| 64 | Biochemical Engineering | 7 | 2.3K | 172 | 50 |
| 65 | Bioengineering | 9 | 2.2K | 304 | 73 |
| 66 | Virology | 27 | 2.1K | 93 | 286 |
| 67 | Biogeochemical cycles | 20 | 2.1K | 18 | 23 |
| 68 | Sustainable Development | 34 | 2.0K | 11 | 12 |
| 69 | Genomics | 38 | 1.8K | 33 | 30 |
| 70 | Molecular ecology | 29 | 1.8K | 83 | 108 |
| 71 | environmental indicators | 41 | 1.8K | 4 | 3 |
| 72 | Soil Science | 44 | 1.8K | 13 | 11 |
| 73 | Birds | 85 | 1.8K | 3 | 3 |
| 74 | Ecosystem management | 26 | 1.6K | 2 | 2 |
| 75 | Ornithology | 72 | 1.6K | 2 | 1 |
| 76 | Population Genetics | 28 | 1.6K | 67 | 88 |
| 76 | plant communities | 39 | 1.6K | 19 | 35 |
| 78 | global environmental change | 41 | 1.6K | 4 | 9 |
| 79 | Geography | 34 | 1.5K | 38 | 24 |
| 80 | Animal Behavior | 23 | 1.4K | 24 | 21 |
| 81 | Aquatic ecology | 28 | 1.4K | 5 | 2 |
| 82 | Hydrometeorology | 4 | 1.4K | 4 | 1 |
| 83 | sustainability | 22 | 1.4K | 2 | 4 |
| 84 | Data Mining | 18 | 1.4K | 13 | 12 |
| 85 | data collection | 17 | 1.4K | 12 | 8 |
| 86 | Plant diseases | 28 | 1.4K | 29 | 15 |
| 87 | gene mapping | 20 | 1.3K | 40 | 40 |
| 88 | atmospheric models | 34 | 1.3K | 9 | 14 |
| 89 | rivers | 13 | 1.3K | 5 | 2 |
| 90 | Parasitology | 25 | 1.2K | 28 | 22 |
| 91 | geological modeling | 11 | 1.1K | 34 | 37 |
| 92 | Geochemical Modeling | 9 | 1.1K | 42 | 37 |
| 93 | Insects | 28 | 1.1K | 15 | 12 |
| 94 | Engineering | 20 | 1.1K | 45 | 14 |
| 95 | Mathematics | 20 | 1.1K | 584 | 85 |
| 96 | Psychophysiology | 7 | 1.0K | 366 | 125 |
| 97 | human behavior | 6 | 955 | 130 | 69 |
| 97 | Behavior | 6 | 955 | 386 | 105 |
| 99 | Ethology | 16 | 940 | 24 | 32 |
| 100 | Fisheries | 18 | 923 | 65 | 39 |
| 101 | Conservation Biology | 24 | 922 | 20 | 32 |
| 102 | bioclimatology | 10 | 881 | 20 | 7 |
| 103 | Immunology | 11 | 879 | 454 | 410 |
| 104 | Economic Development | 7 | 826 | 58 | 32 |
| 104 | Parasitic Diseases | 18 | 826 | 30 | 29 |
| 106 | Oceanography | 21 | 777 | 85 | 80 |
| 107 | Soil ecology | 20 | 759 | 6 | 9 |
| 108 | Computational Biology | 12 | 732 | 118 | 132 |
| 109 | Endocrinology | 14 | 723 | 100 | 138 |
| 110 | herbicides | 3 | 719 | 20 | 3 |
| 111 | Scandinavia | 26 | 712 | 9 | 17 |
| 112 | Flood control | 38 | 698 | 2 | 3 |
| 113 | Geochemistry | 11 | 697 | 120 | 65 |
| 114 | Environmental Toxicology | 20 | 684 | 50 | 72 |
| 115 | weather | 10 | 675 | 14 | 9 |
| 116 | biological invasions | 20 | 670 | 8 | 6 |
| 117 | Climate | 7 | 659 | 12 | 9 |
| 118 | Nanotechnology | 18 | 650 | 603 | 860 |
| 119 | irrigation | 32 | 646 | 2 | 2 |
| 120 | Virulence | 3 | 643 | 98 | 56 |
| 121 | Plant physiology | 11 | 638 | 139 | 128 |
| 122 | Plants | 19 | 625 | 131 | 271 |
| 123 | biological monitoring | 18 | 595 | 4 | 5 |
| 124 | Sustainable agriculture | 32 | 583 | 4 | 8 |
| 125 | Forest Management | 17 | 574 | 12 | 12 |
| 126 | drainage | 30 | 573 | 2 | 2 |
| 127 | Forest Ecology | 16 | 562 | 12 | 15 |
| 128 | Radiation Protection | 38 | 556 | 3 | 3 |
| 129 | Hydraulic Engineering | 21 | 537 | 5 | 8 |
| 130 | Parasites | 15 | 536 | 24 | 25 |
| 131 | Neurology | 2 | 535 | 4133 | 901 |
| 131 | atmosphere | 11 | 535 | 17 | 7 |
| 133 | Geology | 19 | 467 | 104 | 112 |
| 134 | Systems Biology | 8 | 465 | 48 | 33 |
| 135 | Landscape Ecology | 22 | 464 | 4 | 6 |
| 136 | Genetics | 15 | 455 | 231 | 489 |
| 137 | viruses | 2 | 448 | 266 | 79 |
| 138 | sexual behavior | 4 | 443 | 46 | 15 |
| 139 | Wetland ecology | 6 | 425 | 9 | 6 |
| 140 | soil management | 14 | 423 | 5 | 8 |
| 141 | Plant cells | 7 | 405 | 365 | 446 |
| 142 | Meteorites | 3 | 402 | 171 | 43 |
| 143 | Bioinformatics | 4 | 398 | 221 | 146 |
| 144 | Wetland conservation | 5 | 397 | 10 | 6 |
| 144 | Wetlands | 5 | 397 | 11 | 6 |
| 146 | Infections | 1 | 396 | 106 | 36 |
| 146 | infection | 1 | 396 | 222 | 39 |
| 148 | Human genetics | 1 | 390 | 750 | 572 |
| 149 | Epidemiology | 10 | 379 | 336 | 322 |
| 150 | Immunity | 3 | 378 | 509 | 287 |
| 151 | environmental issues | 13 | 375 | 3 | 10 |
| 152 | Energy Policy | 4 | 369 | 118 | 82 |
| 153 | energy resources | 2 | 363 | 114 | 57 |
| 154 | Geobiology | 15 | 355 | 29 | 63 |
| 155 | Land use | 11 | 354 | 29 | 40 |
| 156 | plant molecular biology | 5 | 353 | 385 | 378 |
| 157 | Geomorphology | 10 | 340 | 41 | 56 |
| 158 | Spectrum analysis | 4 | 335 | 439 | 180 |
| 159 | Physical Geography | 6 | 322 | 12 | 4 |
| 160 | Radiation | 6 | 310 | 60 | 28 |
| 161 | Microorganisms | 3 | 307 | 90 | 59 |
| 162 | Medical Microbiology | 2 | 304 | 247 | 127 |
| 163 | Biomass Energy | 10 | 298 | 55 | 99 |
| 164 | Climate Change Mitigation | 2 | 295 | 4 | 3 |
| 164 | Global warming | 2 | 295 | 6 | 3 |
| 164 | sea level | 2 | 295 | 4 | 3 |
| 167 | radiation monitoring | 12 | 294 | 7 | 4 |
| 167 | United States | 9 | 294 | 763 | 470 |
| 169 | natural disasters | 12 | 289 | 15 | 21 |
| 170 | Industrial Microbiology | 5 | 284 | 96 | 92 |
| 171 | Fishery management | 8 | 281 | 88 | 72 |
| 172 | Biomass | 8 | 280 | 11 | 18 |
| 173 | Genetic engineering | 4 | 279 | 173 | 192 |
| 174 | Health Physics | 11 | 275 | 2 | 2 |
| 175 | Public Health | 10 | 274 | 547 | 826 |
| 176 | Invertebrates | 8 | 268 | 17 | 25 |
| 177 | Coastal zone management | 4 | 261 | 12 | 6 |
| 178 | Social behavior | 6 | 251 | 64 | 60 |
| 179 | Host-parasite interactions | 2 | 247 | 144 | 125 |
| 180 | Aquaculture | 6 | 246 | 119 | 74 |
| 181 | emergency management | 9 | 222 | 17 | 17 |
| 182 | mammals | 6 | 221 | 37 | 52 |
| 183 | DNA | 7 | 219 | 18 | 36 |
| 184 | reforestation | 3 | 217 | 7 | 3 |
| 184 | afforestation | 3 | 217 | 7 | 3 |
| 186 | Chemical Ecology | 6 | 209 | 21 | 19 |
| 186 | Ecohydrology | 13 | 209 | 6 | 23 |
| 188 | Forest genetics | 10 | 206 | 5 | 7 |
| 189 | disease vectors | 7 | 198 | 22 | 28 |
| 190 | Algae | 7 | 197 | 70 | 66 |
| 191 | Analytical Chemistry | 5 | 195 | 464 | 371 |
| 192 | Environmental risk assessment | 8 | 192 | 5 | 17 |
| 193 | Marine Ecology | 11 | 191 | 12 | 12 |
| 194 | Environmental Geology | 5 | 189 | 28 | 32 |
| 194 | Chromosome mapping | 3 | 189 | 181 | 182 |
| 196 | transgenic organisms | 2 | 182 | 29 | 10 |
| 197 | environmental control | 6 | 180 | 10 | 19 |
| 198 | Developing countries | 6 | 179 | 114 | 144 |
| 199 | pheromones | 5 | 178 | 20 | 23 |
| 200 | international cooperation | 1 | 174 | 156 | 75 |
| 201 | Agricultural Economics | 3 | 171 | 10 | 4 |
| 201 | Remote Sensing | 5 | 171 | 42 | 28 |
| 201 | Vaccines | 2 | 171 | 228 | 116 |
| 204 | Waste management | 10 | 169 | 24 | 37 |
| 205 | Plant genetic engineering | 1 | 163 | 661 | 424 |
| 205 | transgenic animals | 1 | 163 | 39 | 14 |
| 205 | Transgenic plants | 1 | 163 | 72 | 31 |
| 208 | Agricultural Science | 5 | 157 | 4 | 26 |
| 208 | Agronomy | 5 | 157 | 49 | 64 |
| 210 | Cell Biology | 2 | 154 | 4616 | 3378 |
| 211 | Cosmochemistry | 6 | 153 | 16 | 24 |
| 212 | environmental exposure | 8 | 150 | 100 | 185 |
| 213 | Water chemistry | 3 | 148 | 35 | 10 |
| 214 | Molecular evolution | 4 | 144 | 136 | 193 |
| 215 | Chemical Engineering | 3 | 138 | 1723 | 1394 |
| 215 | Restoration Ecology | 9 | 138 | 20 | 74 |
| 217 | Biophysics | 6 | 136 | 1205 | 1644 |
| 218 | Mountains | 1 | 135 | 91 | 9 |
| 219 | Seaweed | 3 | 134 | 135 | 95 |
| 220 | Immunotherapy | 1 | 131 | 357 | 258 |
| 220 | Immune system | 1 | 131 | 566 | 320 |
| 222 | Marine Pollution | 3 | 129 | 54 | 55 |
| 222 | Agricultural systems | 2 | 129 | 18 | 15 |
| 224 | Natural resources | 4 | 128 | 53 | 70 |
| 224 | Hydrodynamics | 4 | 128 | 12 | 19 |
| 226 | Metallurgy | 4 | 126 | 313 | 267 |
| 226 | Electrochemistry | 4 | 126 | 788 | 607 |
| 226 | Aerosols | 2 | 126 | 40 | 24 |
| 229 | Risk Management | 8 | 125 | 35 | 131 |
| 229 | Flood forecasting | 8 | 125 | 4 | 20 |
| 229 | polar regions | 5 | 125 | 20 | 21 |
| 232 | Phylogeny | 2 | 124 | 94 | 72 |
| 233 | Cytology | 3 | 122 | 2390 | 2898 |
| 234 | Physiology | 4 | 121 | 1804 | 2301 |
| 234 | soil conservation | 4 | 121 | 110 | 147 |
| 236 | Geographic information systems | 1 | 120 | 101 | 25 |
| 237 | Nanostructures | 2 | 114 | 192 | 202 |
| 238 | Ecological Genetics | 6 | 109 | 17 | 22 |
| 239 | air quality management | 5 | 107 | 74 | 188 |
| 239 | Nanostructured Materials | 2 | 107 | 3798 | 3399 |
| 239 | Nanoparticles | 2 | 107 | 2971 | 2871 |
| 242 | sustainable growth | 1 | 104 | 1 | 1 |
| 243 | Diagnostic microbiology | 2 | 103 | 109 | 169 |
| 244 | Fluid Mechanics | 8 | 102 | 34 | 80 |
| 244 | River Engineering | 8 | 102 | 1 | 1 |
| 246 | Microbiota | 2 | 101 | 6 | 3 |
| 247 | Pharmacology | 2 | 100 | 4234 | 3450 |
| 247 | Ecological Engineering | 4 | 100 | 20 | 43 |
| 249 | Australia | 2 | 99 | 945 | 452 |
| 249 | bees | 1 | 99 | 34 | 15 |
| 251 | Wildlife management | 5 | 97 | 109 | 102 |
| 252 | Thorax | 1 | 96 | 65 | 43 |
| 253 | Green Chemistry | 1 | 95 | 1614 | 1089 |
| 254 | Protozoa | 4 | 94 | 72 | 99 |
| 255 | Radioisotopes | 3 | 91 | 119 | 57 |
| 256 | Fisheries Law | 3 | 90 | 40 | 73 |
| 256 | fisheries management | 3 | 90 | 40 | 73 |
| 258 | Luminescence | 1 | 89 | 600 | 111 |
| 258 | bioluminescence | 1 | 89 | 507 | 86 |
| 260 | animals | 4 | 88 | 96 | 94 |
| 261 | Chemical industry | 1 | 86 | 892 | 263 |
| 262 | Water quality management | 4 | 85 | 105 | 149 |
| 263 | Neuroendocrinology | 1 | 82 | 19 | 26 |
| 264 | indoor air pollution | 1 | 81 | 344 | 257 |
| 264 | Ventilation | 1 | 81 | 359 | 258 |
| 264 | Sick building syndrome | 1 | 81 | 344 | 257 |
| 267 | energy development | 2 | 77 | 77 | 99 |
| 268 | Renewable Energy Sources | 3 | 76 | 251 | 452 |
| 268 | soil pollution | 2 | 76 | 28 | 25 |
| 270 | enzymes | 2 | 74 | 132 | 169 |
| 271 | Social Sciences | 2 | 73 | 825 | 535 |
| 271 | Humanities | 2 | 73 | 204 | 135 |
| 273 | Plant breeding | 3 | 72 | 121 | 132 |
| 274 | Pesticide residues | 1 | 67 | 9 | 11 |
| 274 | Food additives | 1 | 67 | 153 | 115 |
| 274 | food contamination | 1 | 67 | 356 | 125 |
| 274 | nucleic acids | 1 | 67 | 415 | 472 |
| 278 | energy conservation | 1 | 61 | 1082 | 491 |
| 278 | Soil fertility | 2 | 61 | 20 | 31 |
| 280 | Neurophysiology | 1 | 59 | 1084 | 1168 |
| 281 | Freshwater invertebrates | 3 | 58 | 12 | 20 |
| 281 | Mass Spectrometry | 4 | 58 | 293 | 549 |
| 283 | land degradation | 3 | 56 | 145 | 378 |
| 283 | Genetic markers | 1 | 56 | 30 | 20 |
| 283 | biochemical markers | 1 | 56 | 239 | 265 |
| 283 | degradation | 3 | 56 | 145 | 378 |
| 287 | Water Purification | 1 | 54 | 93 | 81 |
| 288 | Civil Engineering | 1 | 52 | 144 | 40 |
| 288 | proteins | 3 | 52 | 720 | 1092 |
| 290 | Economic History | 1 | 50 | 1489 | 659 |
| 290 | Development | 1 | 50 | 142 | 120 |
| 290 | Economic Assistance | 1 | 50 | 105 | 93 |
| 290 | world | 1 | 50 | 132 | 122 |
| 294 | Cartography | 1 | 49 | 53 | 20 |
| 294 | Public Administration | 1 | 49 | 716 | 405 |
| 294 | Geodesy | 1 | 49 | 67 | 44 |
| 297 | health services accessibility | 5 | 48 | 58 | 154 |
| 297 | Environmental hydraulics | 2 | 48 | 1 | 1 |
| 299 | Psychology | 2 | 44 | 3197 | 4100 |
| 299 | investigative techniques | 1 | 44 | 59 | 58 |
| 301 | Environmental Economics | 1 | 43 | 48 | 48 |
| 301 | Biometrics | 2 | 43 | 1016 | 866 |
| 301 | coal | 1 | 43 | 122 | 149 |
| 304 | Mycology | 2 | 42 | 211 | 242 |
| 304 | Fungi | 2 | 42 | 74 | 119 |
| 306 | Comparative Physiology | 1 | 39 | 85 | 112 |
| 306 | Scotland | 6 | 39 | 1 | 3 |
| 308 | Psychiatry | 1 | 37 | 3718 | 3684 |
| 308 | Global Health | 3 | 37 | 125 | 379 |
| 310 | occupational diseases | 2 | 36 | 283 | 526 |
| 311 | California | 1 | 35 | 132 | 115 |
| 312 | Health equity | 1 | 33 | 13 | 10 |
| 312 | urban health | 1 | 33 | 84 | 114 |
| 312 | plankton | 1 | 33 | 24 | 27 |
| 315 | Sociology | 3 | 32 | 468 | 1180 |
| 315 | Plant Pathology | 1 | 32 | 108 | 74 |
| 315 | Animal genetics | 2 | 32 | 181 | 345 |
| 315 | Watershed management | 2 | 32 | 11 | 14 |
| 315 | Great Lakes | 2 | 32 | 24 | 36 |
| 320 | wetland management | 1 | 28 | 14 | 16 |
| 321 | preventive medicine | 2 | 27 | 225 | 500 |
| 321 | Travel | 2 | 27 | 96 | 152 |
| 323 | Environmental Psychology | 1 | 26 | 24 | 55 |
| 324 | Radiology | 1 | 25 | 259 | 214 |
| 324 | Bioremediation | 2 | 25 | 86 | 263 |
| 324 | Molecular cloning | 1 | 25 | 197 | 335 |
| 324 | Genetic recombination | 1 | 25 | 194 | 323 |
| 324 | Radiobiology | 1 | 25 | 499 | 470 |
| 324 | Recombinant DNA | 1 | 25 | 214 | 357 |
| 324 | Population | 2 | 25 | 98 | 188 |
| 331 | Hydrogeology | 1 | 24 | 56 | 95 |
| 331 | Engineering Geology | 1 | 24 | 201 | 249 |
| 331 | Plant Morphology | 2 | 24 | 23 | 58 |
| 331 | Physical Chemistry | 1 | 24 | 571 | 680 |
| 331 | Solutions | 1 | 24 | 16 | 13 |
| 331 | Tropical Medicine | 1 | 24 | 1603 | 1473 |
| 331 | DNA polymerases | 1 | 24 | 102 | 234 |
| 338 | Robotics | 1 | 23 | 540 | 640 |
| 338 | Regional Planning | 1 | 23 | 719 | 757 |
| 338 | Quality Control | 1 | 23 | 834 | 882 |
| 338 | Bioacoustics | 1 | 23 | 9 | 6 |
| 338 | Water Microbiology | 1 | 23 | 54 | 88 |
| 338 | Groundwater | 1 | 23 | 150 | 197 |
| 338 | nanoscience | 1 | 23 | 598 | 982 |
| 338 | city planning | 1 | 23 | 530 | 563 |
| 346 | Maps | 2 | 22 | 5 | 9 |
| 347 | Biological Systems | 1 | 21 | 91 | 141 |
| 347 | water reuse | 1 | 21 | 26 | 31 |
| 349 | Food Safety | 1 | 20 | 261 | 287 |
| 349 | Europe | 1 | 20 | 1163 | 1201 |
| 351 | Public Policy | 3 | 19 | 185 | 691 |
| 351 | Genetically modified organisms | 1 | 19 | 7 | 7 |
| 351 | plant viruses | 1 | 19 | 31 | 42 |
| 351 | safety | 1 | 19 | 16 | 20 |
| 351 | Radiation dosimetry | 1 | 19 | 47 | 36 |
| 356 | Animal Nutrition | 1 | 18 | 369 | 455 |
| 356 | Animal breeding | 1 | 18 | 399 | 432 |
| 356 | Medical Anthropology | 1 | 18 | 449 | 786 |
| 356 | Raman spectroscopy | 1 | 18 | 415 | 704 |
| 356 | Enzyme | 1 | 18 | 50 | 99 |
| 361 | Urban Policy | 2 | 17 | 38 | 126 |
| 361 | urban forestry | 2 | 17 | 15 | 33 |
| 363 | Microbial Metabolism | 1 | 16 | 17 | 33 |
| 363 | hazard mitigation | 1 | 16 | 83 | 115 |
| 363 | China | 3 | 16 | 426 | 1304 |
| 363 | aerosol | 1 | 16 | 65 | 61 |
| 367 | Epigenetics | 1 | 15 | 27 | 49 |
| 367 | Epigenomics | 1 | 15 | 27 | 48 |
| 367 | Marine mammals | 1 | 15 | 140 | 241 |
| 370 | Surface Chemistry | 1 | 14 | 1177 | 1693 |
| 370 | Colloids | 1 | 14 | 854 | 1459 |
| 370 | radioactive waste | 1 | 14 | 58 | 180 |
| 370 | industrial waste | 1 | 14 | 61 | 180 |
| 370 | Sociobiology | 1 | 14 | 27 | 38 |
| 370 | Hazardous waste | 1 | 14 | 72 | 208 |
| 370 | Structure-activity relationship | 1 | 14 | 40 | 81 |
| 370 | Acarology | 2 | 14 | 18 | 42 |
| 370 | Mites | 2 | 14 | 28 | 48 |
| 370 | Ticks | 2 | 14 | 22 | 42 |
| 370 | Acari | 2 | 14 | 18 | 41 |
| 381 | forest policy | 1 | 12 | 35 | 77 |
| 382 | Proteomics | 1 | 11 | 193 | 481 |
| 382 | Health Policy | 2 | 11 | 800 | 3012 |
| 382 | Sedimentology | 1 | 11 | 229 | 486 |
| 382 | protein | 1 | 11 | 1010 | 1570 |
| 382 | bats | 1 | 11 | 10 | 19 |
| 382 | Fertilizers | 2 | 11 | 17 | 58 |
| 388 | Marine biodiversity | 1 | 10 | 24 | 27 |
| 389 | Paleontology | 2 | 9 | 525 | 1404 |
| 389 | Nuclear Chemistry | 1 | 9 | 358 | 403 |
| 389 | Radiochemistry | 1 | 9 | 101 | 138 |
| 389 | Reservoirs | 1 | 9 | 35 | 76 |
| 389 | lakes | 1 | 9 | 30 | 67 |
| 389 | wildlife diseases | 1 | 9 | 18 | 34 |
| 395 | Medical Technology | 1 | 8 | 345 | 925 |
| 395 | Medical Laboratory Science | 1 | 8 | 308 | 686 |
| 395 | Atmospheric Science | 2 | 8 | 14 | 41 |
| 395 | Systems Analysis | 1 | 8 | 110 | 238 |
| 395 | Stochastic Processes | 1 | 8 | 302 | 416 |
| 395 | Aquatic ecosystems | 1 | 8 | 20 | 26 |
| 395 | System analysis | 1 | 8 | 405 | 802 |
| 402 | Archaeology | 1 | 7 | 337 | 434 |
| 402 | landscapes | 1 | 7 | 17 | 29 |
| 402 | visualization | 3 | 7 | 552 | 1547 |
| 402 | Recycling | 1 | 7 | 59 | 171 |
| 406 | Water quality | 1 | 6 | 204 | 615 |
| 406 | big data | 1 | 6 | 35 | 92 |
| 406 | space environment | 1 | 6 | 195 | 389 |
| 406 | Mitochondrial DNA | 1 | 6 | 18 | 37 |
| 410 | Organic Geochemistry | 2 | 5 | 13 | 62 |
| 410 | water resources | 1 | 5 | 16 | 29 |
| 412 | Environmental Geography | 1 | 4 | 25 | 77 |
| 412 | Human Geography | 1 | 4 | 356 | 872 |
| 412 | Crystallization | 1 | 4 | 47 | 97 |
| 412 | Crystallography | 1 | 4 | 168 | 269 |
| 412 | X-ray crystallography | 1 | 4 | 81 | 149 |
| 417 | Risk assessment | 1 | 3 | 65 | 178 |
| 417 | ecological risk assessment | 1 | 3 | 27 | 75 |
| 417 | Bipolar Disorder | 1 | 3 | 600 | 1388 |
| 417 | Randomized Controlled Trials | 1 | 3 | 200 | 513 |
| 417 | Africa | 1 | 3 | 495 | 1236 |
| 417 | Continental shelf | 1 | 3 | 36 | 85 |
| 417 | Health Risk Assessment | 1 | 3 | 57 | 139 |
| 417 | disaster relief | 1 | 3 | 94 | 501 |
| 417 | Isotopes | 1 | 3 | 10 | 28 |
| 426 | Computer Science | 1 | 2 | 474 | 1155 |
| 426 | History | 4 | 2 | 55 | 355 |
| 426 | Bryology | 1 | 2 | 38 | 82 |
| 426 | Horticulture | 1 | 2 | 190 | 472 |
| 426 | Marine Meteorology | 1 | 2 | 47 | 94 |
| 426 | Alternative Medicine | 1 | 2 | 317 | 932 |
| 426 | complementary therapies | 1 | 2 | 365 | 1063 |
| 426 | bryophytes | 1 | 2 | 27 | 69 |
| 426 | Respiration | 1 | 2 | 210 | 666 |
| 426 | Radiation effects | 2 | 2 | 34 | 187 |
| 436 | Landscape Architecture | 1 | 1 | 17 | 49 |
| 436 | Japan | 1 | 1 | 749 | 1968 |
| 436 | Dementia | 2 | 1 | 1287 | 3896 |
| 436 | Alzheimer's disease | 2 | 1 | 1292 | 3940 |
| 436 | Egypt | 2 | 1 | 30 | 145 |
| 441 | Geriatrics | 1 | 0 | 3499 | 8199 |
| 441 | Agricultural Chemistry | 1 | 0 | 384 | 972 |
| 441 | Rural Development | 1 | 0 | 102 | 432 |
| 441 | Immunochemistry | 2 | 0 | 73 | 441 |
| 441 | radiative transfer | 1 | 0 | 41 | 113 |
| 441 | Gerontology | 1 | 0 | 793 | 2022 |
| 441 | Elderly | 1 | 0 | 306 | 460 |
| 441 | older people | 1 | 0 | 430 | 829 |
| 441 | Aging | 1 | 0 | 1137 | 2861 |
