Table 3. Diagnostic terms and dominant topics for the 50 largest (of 70) clusters from the PNAS high-impact map.
| Cluster | Mean Year | No. of papers | MeSH term 1 | MeSH term 2 | Dominant PNAS topic 1997-2001, % |
|---|---|---|---|---|---|
| 3 | 1987.40 | 242 | *Oncogenes | DNA restriction enzymes | Biochemistry (30.8) |
| 4 | 1987.79 | 483 | *Genes, structural | DNA restriction enzymes | |
| 5 | 1987.82 | 524 | Cloning, molecular | Nucleic acid hybridization | Genetics (37.5) |
| 6 | 1988.17 | 281 | Oxidation-reduction | Lipoproteins, LDL/*metabolism | Medical Sciences (36.4) |
| 7 | 1988.46 | 339 | Electrophoresis, polyacrylamide gel | Alzheimer's disease/*pathology | Biochemistry (33.3) |
| 8 | 1988.80 | 194 | Mutation | Collagen/metabolism | Medical Sciences (33.3) |
| 9 | 1988.93 | 94 | Buthionine sulfoximine | Bacteriorhodopsins/genetics/*metabolism | Cell Biology (33.3) |
| 10 | 1988.96 | 348 | Nucleic acid hybridization | Escherichia coli genetics | Biochemistry (26.7) |
| 12 | 1989.25 | 492 | Cloning, molecular | Sequence homology, nucleic acid | Microbiology (31.3) |
| 13 | 1989.29 | 254 | Transforming growth factors | Biochemistry (20.7) | |
| 14 | 1989.37 | 162 | DNA restriction enzymes | H-2 Antigens/*genetics | Medical Sciences (50.0) |
| 16 | 1990.00 | 313 | Chromatography, affinity | Tumor necrosis factor | Biochemistry (25.6) |
| 17 | 1990.74 | 93 | Sarcoma viruses, avian | Biochemistry (34.8) | |
| 18 | 1990.93 | 127 | Neutralization tests | HIV-1/*immunology | Genetics (72.7) |
| 19 | 1991.03 | 171 | ADP-ribosylation factors | Hemochromatosis/genetics/* metabolism | Medical Sciences (36.4) |
| 22 | 1991.26 | 208 | *DNA replication | Biochemistry (34.4) | |
| 23 | 1991.41 | 144 | P-glycoprotein | Drug resistance/*genetics | Cell Biology (21.4) |
| 24 | 1991.45 | 130 | Autoradiography | Receptors, opiod/*metabolism | Biochemistry (32.4) |
| 25 | 1991.99 | 193 | Chromosome mapping | Genetics (16.7) | |
| 26 | 1992.20 | 172 | Receptors, fibroblast growth factor | Receptors, calcitriol | Biochemistry (33.3) |
| 28 | 1992.44 | 272 | Gene expression | Gene library | Biochemistry (34.5) |
| 29 | 1993.35 | 203 | Electric conductivity | Synapses/*physiology | Neurobiology (62.5) |
| 31 | 1993.77 | 117 | *Nucleic acid conformation | Biochemistry (25.5) | |
| 32 | 1993.87 | 157 | HIV-I reverse transcriptase | *Reverse transcriptase Inhibitors | Biochemistry (39.5) |
| 36 | 1994.58 | 304 | Alzheimer's disease/*metabolism | Amyloid β protein/*metabolism | Neurobiology (35.7) |
| 38 | 1994.78 | 200 | Phosphotyrosine | Protein-tyrosine kinase/*metabolism | Medical Sciences (22.2) |
| 40 | 1995.05 | 137 | Phylogeny | Bone marrow cells | Evolution (23.5) |
| 41 | 1995.10 | 229 | Comparative study | Sequence homology, amino acid | Medical Sciences (18.0) |
| 42 | 1995.10 | 90 | Magnetic resonance imaging | Photic stimulation | Neurobiology (44.9) |
| 43 | 1995.12 | 263 | Nitric oxide/ * metabolism | ω-N-Methylarginine | Medical Sciences (38.7) |
| 46 | 1995.32 | 155 | Brain-derived neurotrophic factor | Nerve tissue proteins/*pharmacology | Neurobiology (45.8) |
| 47 | 1995.42 | 234 | *Cell cycle | *Genes, p53 | Cell Biology (31.9) |
| 48 | 1995.54 | 92 | Photosynthetic Reaction Center, bacterial | *Bacterial proteins | Neurobiology (32.6) |
| 49 | 1995.64 | 150 | *Protein folding | *Protein conformation | Biophysics (69.4) |
| 50 | 1995.65 | 302 | Molecular sequence data | *Genetic vectors | Biochemistry (22.8) |
| 52 | 1996.09 | 156 | Cytotoxicity, immunologic | Killer cells, natural/ *immunology | Immunology (53.4) |
| 53 | 1996.10 | 200 | Lymphocyte transformation | Immunology (33.0) | |
| 57 | 1996.54 | 176 | RNA, messenger/genetics/metabolism | Defensins | Biochemistry (19.3) |
| 59 | 1996.86 | 173 | DNA primers | Tetracycline/*pharmacology | Biochemistry (22.8) |
| 60 | 1997.00 | 82 | cIF-2 kinase | NF-κ B/*antagonists & inhibitors | Immunology (33.3) |
| 61 | 1997.21 | 227 | *DNA repair | Leptin | Medical Sciences (28.8) |
| 62 | 1997.35 | 215 | Protein p53/*metabolism | *Genetics, population | Medical Sciences (24.6) |
| 63 | 1997.45 | 183 | Sirolimus | 1-phosphatidylinositol 3-Kinase/metabolism | Cell Biology (27.3) |
| 64 | 1997.63 | 286 | *Apoptosis | Protooncogene proteins c-bcl-2 | Cell Biology (24.5) |
| 65 | 1997.92 | 139 | Ubiquitins/*metabolism | Multienzyme complexes/*metabolism | Cell Biology (29.6) |
| 66 | 1997.93 | 205 | Models, molecular | Crystallography, x-Ray | Biochemistry (49.0) |
| 67 | 1997.94 | 120 | Neoplasm transplantation | Serine endopeptidases/*metabolism | Medical Sciences (25.0) |
| 68 | 1998.01 | 123 | Adenomatous polyposis coli protein | Genes, APC | Medical Sciences(22.4) |
| 69 | 1998.31 | 222 | Tumor cells, cultured | *Telomere | Biochemistry (31.7) |
| 70 | 1999.55 | 162 | Gene expression profiling | Oligonucleotide array sequence analysis | Genetics (27.1) |
Italics indicate topics with <30% dominance of a cluster.