[{"sf": "ABC", "lfs": [{"lf": "ATP-binding cassette", "freq": 1437, "since": 1990, "vars": [{"lf": "ATP-binding cassette", "freq": 1057, "since": 1990}, {"lf": "ATP binding cassette", "freq": 248, "since": 1991}, {"lf": "ATP-binding-cassette", "freq": 33, "since": 1992}, {"lf": "adenosine triphosphate-binding cassette", "freq": 23, "since": 1998}, {"lf": "ATP)-binding cassette", "freq": 16, "since": 1997}, {"lf": "ATP-Binding Cassette", "freq": 13, "since": 1993}, {"lf": "ATP Binding Cassette", "freq": 12, "since": 1998}, {"lf": "adenosine triphosphate binding cassette", "freq": 9, "since": 1993}, {"lf": "ATP-binding Cassette", "freq": 4, "since": 1993}, {"lf": "Adenosine triphosphate-binding cassette", "freq": 3, "since": 2007}, {"lf": "ATP-binding cassettes", "freq": 3, "since": 1996}, {"lf": "ATP) binding cassette", "freq": 3, "since": 2004}, {"lf": "adenosine triphosphate-binding-cassette", "freq": 2, "since": 2003}, {"lf": "ATP] binding cassette", "freq": 1, "since": 2005}, {"lf": "adenosine triphosphate)-binding cassette", "freq": 1, "since": 2005}, {"lf": "ATP-BINDING CASSETTE", "freq": 1, "since": 2007}, {"lf": "ATP)-binding-cassette", "freq": 1, "since": 1998}, {"lf": "ATP) Binding Cassette", "freq": 1, "since": 1994}, {"lf": "Atp binding cassette", "freq": 1, "since": 1997}, {"lf": "ATP binding-cassette", "freq": 1, "since": 2004}, {"lf": "ATP- binding cassette", "freq": 1, "since": 2004}, {"lf": "adenosine-triphosphate-binding cassette", "freq": 1, "since": 2007}, {"lf": "Adenosine triphosphate binding cassette", "freq": 1, "since": 2003}, {"lf": "adenosine triphosphate- binding cassette", "freq": 1, "since": 2004}]}, {"lf": "avidin-biotin-peroxidase complex", "freq": 560, "since": 1981, "vars": [{"lf": "avidin-biotin-peroxidase complex", "freq": 218, "since": 1981}, {"lf": "avidin-biotin complex", "freq": 145, "since": 1982}, {"lf": "avidin-biotin peroxidase complex", "freq": 49, "since": 1983}, {"lf": "avidin-biotin-complex", "freq": 28, "since": 1985}, {"lf": "avidin biotin complex", "freq": 13, "since": 1984}, {"lf": "avidin-biotinylated peroxidase complex", "freq": 12, "since": 1987}, {"lf": "Avidin-Biotin Complex", "freq": 10, "since": 1985}, {"lf": "Avidin-Biotin-Peroxidase Complex", "freq": 6, "since": 1986}, {"lf": "avidin-biotin-peroxidase-complex", "freq": 6, "since": 1984}, {"lf": "avidin biotin peroxidase complex", "freq": 5, "since": 1985}, {"lf": "Avidin-biotin-peroxidase complex", "freq": 5, "since": 1986}, {"lf": "Avidin-Biotin-Complex", "freq": 4, "since": 1992}, {"lf": "avidinbiotin peroxidase complex", "freq": 4, "since": 1985}, {"lf": "avidin-biotin-peroxidase complexes", "freq": 3, "since": 1983}, {"lf": "Avidin-Biotin complex", "freq": 3, "since": 1994}, {"lf": "streptavidin-biotin complex", "freq": 3, "since": 1994}, {"lf": "indirect avidin-biotin-peroxidase", "freq": 3, "since": 1984}, {"lf": "avidin-biotin-horseradish peroxidase complex", "freq": 3, "since": 1986}, {"lf": "avidinbiotin-peroxidase complex", "freq": 3, "since": 1983}, {"lf": "Avidin-biotin-complex", "freq": 2, "since": 1990}, {"lf": "avidin--biotin--peroxidase complex", "freq": 2, "since": 1982}, {"lf": "Avidin biotin peroxidase complex", "freq": 2, "since": 1989}, {"lf": "avidin-biotin complexes", "freq": 2, "since": 1986}, {"lf": "avidin biotin peroxidase-complex", "freq": 2, "since": 1988}, {"lf": "avidin-biotin immunoperoxidase complex", "freq": 2, "since": 1991}, {"lf": "avidin--biotin--immunoperoxidase complex", "freq": 1, "since": 1984}, {"lf": "avidin--biotinylated peroxidase complex", "freq": 1, "since": 1983}, {"lf": "Avidin Biotin Peroxidase Complex", "freq": 1, "since": 1989}, {"lf": "avidin biotin-complex", "freq": 1, "since": 1989}, {"lf": "Avidin-Biotin peroxidase complex", "freq": 1, "since": 1990}, {"lf": "avidin biotin-peroxidase complex", "freq": 1, "since": 1990}, {"lf": "avidin-biotinylated peroxidase complexes", "freq": 1, "since": 1983}, {"lf": "Avidin-biotin immunoperoxidase complex", "freq": 1, "since": 1999}, {"lf": "avidine-biotin-peroxidase complex", "freq": 1, "since": 1988}, {"lf": "avidin/biotin-peroxidase complex", "freq": 1, "since": 1985}, {"lf": "Avidin-Biotin peroxidase Complex", "freq": 1, "since": 1987}, {"lf": "Avidin-biotin complex", "freq": 1, "since": 2007}, {"lf": "avidin-biotin-immunoperoxidase complex", "freq": 1, "since": 1990}, {"lf": "avidin:biotin complex", "freq": 1, "since": 1992}, {"lf": "Avidin Biotin peroxidase Complex", "freq": 1, "since": 1989}, {"lf": "avidin biotinylated peroxidase complex", "freq": 1, "since": 1992}, {"lf": "avidine-biotine complex", "freq": 1, "since": 1994}, {"lf": "Avidin Biotin-Peroxidase Complex", "freq": 1, "since": 1989}, {"lf": "avidin-biotinated horseradish peroxidase complex", "freq": 1, "since": 1983}, {"lf": "avidin -biotin peroxidase complex", "freq": 1, "since": 1992}, {"lf": "avidine-biotin complex", "freq": 1, "since": 1992}, {"lf": "Avidin Biotin Complex", "freq": 1, "since": 1990}, {"lf": "Avidin-Biotin-Peroxidase complex", "freq": 1, "since": 1984}, {"lf": "avidin/biotin complex", "freq": 1, "since": 2005}, {"lf": "Avidin biotin peroxidase-complex", "freq": 1, "since": 1987}]}, {"lf": "aneurysmal bone cyst", "freq": 106, "since": 1980, "vars": [{"lf": "aneurysmal bone cyst", "freq": 51, "since": 1980}, {"lf": "Aneurysmal bone cyst", "freq": 28, "since": 1988}, {"lf": "aneurysmal bone cysts", "freq": 15, "since": 1984}, {"lf": "Aneurysmal bone cysts", "freq": 12, "since": 1991}]}, {"lf": "abacavir", "freq": 87, "since": 1998, "vars": [{"lf": "abacavir", "freq": 80, "since": 2000}, {"lf": "Abacavir", "freq": 7, "since": 1998}]}, {"lf": "advanced breast cancer", "freq": 81, "since": 1993, "vars": [{"lf": "advanced breast cancer", "freq": 72, "since": 1993}, {"lf": "advanced breast carcinoma", "freq": 5, "since": 1994}, {"lf": "Adjuvant Breast Cancer", "freq": 2, "since": 2002}, {"lf": "Advanced breast cancer", "freq": 1, "since": 2004}, {"lf": "adjuvant breast cancer", "freq": 1, "since": 1994}]}, {"lf": "antibody binding capacity", "freq": 67, "since": 1975, "vars": [{"lf": "antibody binding capacity", "freq": 29, "since": 1994}, {"lf": "antigen-binding cells", "freq": 12, "since": 1975}, {"lf": "antibody-binding capacity", "freq": 9, "since": 1996}, {"lf": "antigen binding cells", "freq": 3, "since": 1979}, {"lf": "Antigen-binding cells", "freq": 3, "since": 1975}, {"lf": "antibody binding capacities", "freq": 3, "since": 1997}, {"lf": "antigen binding capacity", "freq": 3, "since": 1976}, {"lf": "antigen-binding capacity", "freq": 2, "since": 1982}, {"lf": "antigen binding cell", "freq": 1, "since": 1981}, {"lf": "Antigen binding capacity", "freq": 1, "since": 1978}, {"lf": "Antibody binding capacity", "freq": 1, "since": 2003}]}, {"lf": "Aberrant Behavior Checklist", "freq": 60, "since": 1986, "vars": [{"lf": "Aberrant Behavior Checklist", "freq": 29, "since": 1991}, {"lf": "Autism Behavior Checklist", "freq": 20, "since": 1986}, {"lf": "Aberrant Behaviour Checklist", "freq": 5, "since": 1997}, {"lf": "aberrant behavior checklist", "freq": 3, "since": 2005}, {"lf": "aberrant behaviour checklist", "freq": 1, "since": 2002}, {"lf": "autism behavior checklist", "freq": 1, "since": 2006}, {"lf": "Aberrant Behavioral Checklist", "freq": 1, "since": 2001}]}, {"lf": "activity-based costing", "freq": 47, "since": 1995, "vars": [{"lf": "activity-based costing", "freq": 23, "since": 1995}, {"lf": "Activity-based costing", "freq": 8, "since": 1995}, {"lf": "Activity Based Costing", "freq": 4, "since": 2001}, {"lf": "activity based costing", "freq": 4, "since": 2002}, {"lf": "activity-based cost", "freq": 2, "since": 2000}, {"lf": "Activity Based Cost", "freq": 1, "since": 2003}, {"lf": "Activity-Based Cost", "freq": 1, "since": 2001}, {"lf": "Activity-Based Costing", "freq": 1, "since": 2001}, {"lf": "Activity-based cost", "freq": 1, "since": 1997}, {"lf": "activity-based-costing", "freq": 1, "since": 2000}, {"lf": "Activity based costing", "freq": 1, "since": 1996}]}, {"lf": "Activities-specific Balance Confidence", "freq": 36, "since": 1995, "vars": [{"lf": "Activities-specific Balance Confidence", "freq": 23, "since": 1995}, {"lf": "Activities-Specific Balance Confidence", "freq": 9, "since": 2000}, {"lf": "activities-specific balance confidence", "freq": 3, "since": 1998}, {"lf": "Activity-specific Balance Confidence", "freq": 1, "since": 2004}]}, {"lf": "argon beam coagulator", "freq": 35, "since": 1988, "vars": [{"lf": "argon beam coagulator", "freq": 21, "since": 1990}, {"lf": "argon beam coagulation", "freq": 4, "since": 2001}, {"lf": "Argon Beam Coagulator", "freq": 4, "since": 1988}, {"lf": "argon-beam coagulator", "freq": 3, "since": 2002}, {"lf": "Argon beam coagulation", "freq": 1, "since": 1994}, {"lf": "argon-beam coagulation", "freq": 1, "since": 2002}, {"lf": "Argon Beam Coagulation", "freq": 1, "since": 2006}]}, {"lf": "aspiration biopsy cytology", "freq": 33, "since": 1979, "vars": [{"lf": "aspiration biopsy cytology", "freq": 24, "since": 1981}, {"lf": "Aspiration biopsy cytology", "freq": 7, "since": 1979}, {"lf": "Aspiration-biopsy-cytology", "freq": 1, "since": 1986}, {"lf": "Aspiration Biopsy Cytology", "freq": 1, "since": 1986}]}, {"lf": "active breathing control", "freq": 33, "since": 1999, "vars": [{"lf": "active breathing control", "freq": 23, "since": 1999}, {"lf": "Active breathing control", "freq": 4, "since": 2000}, {"lf": "active breathing coordinator", "freq": 2, "since": 2006}, {"lf": "active breath control", "freq": 1, "since": 2005}, {"lf": "Active Breathing Control", "freq": 1, "since": 2001}, {"lf": "Active Breathing Coordinator", "freq": 1, "since": 2008}, {"lf": "active breath-control", "freq": 1, "since": 2008}]}, {"lf": "activated B-cell-like", "freq": 28, "since": 2001, "vars": [{"lf": "activated B-cell-like", "freq": 16, "since": 2002}, {"lf": "activated B cell-like", "freq": 9, "since": 2001}, {"lf": "germinal center B-cell (GCB)-like and activated B-cell", "freq": 2, "since": 2004}, {"lf": "germinal center B-cell (GCB)-like and activated-B-cell", "freq": 1, "since": 2007}]}, {"lf": "absolute blast count", "freq": 10, "since": 1992, "vars": [{"lf": "absolute blast count", "freq": 5, "since": 1996}, {"lf": "absolute band count", "freq": 3, "since": 1992}, {"lf": "Absolute band counts", "freq": 1, "since": 2002}, {"lf": "absolute blasts count", "freq": 1, "since": 2005}]}, {"lf": "adenoid basal carcinoma", "freq": 8, "since": 1988, "vars": [{"lf": "adenoid basal carcinoma", "freq": 5, "since": 1988}, {"lf": "Adenoid basal carcinoma", "freq": 3, "since": 1996}]}, {"lf": "approximate Bayesian computation", "freq": 8, "since": 2005, "vars": [{"lf": "approximate Bayesian computation", "freq": 5, "since": 2005}, {"lf": "Approximate Bayesian Computation", "freq": 1, "since": 2007}, {"lf": "Approximate Bayesian computation", "freq": 1, "since": 2005}, {"lf": "approximate Bayesian computational", "freq": 1, "since": 2006}]}, {"lf": "antibodies bound per cell", "freq": 7, "since": 2000, "vars": [{"lf": "antibodies bound per cell", "freq": 5, "since": 2000}, {"lf": "antibody bound per cell", "freq": 1, "since": 2006}, {"lf": "Antibodies Bound per Cell", "freq": 1, "since": 2008}]}, {"lf": "alveolar bone crest", "freq": 6, "since": 1985, "vars": [{"lf": "alveolar bone crest", "freq": 6, "since": 1985}]}, {"lf": "accelerated blood clearance", "freq": 6, "since": 2004, "vars": [{"lf": "accelerated blood clearance", "freq": 4, "since": 2004}, {"lf": "Accelerated blood clearance", "freq": 2, "since": 2008}]}, {"lf": "Alternative Birthing Center", "freq": 4, "since": 1980, "vars": [{"lf": "Alternative Birthing Center", "freq": 2, "since": 1980}, {"lf": "alternative birth center", "freq": 1, "since": 1983}, {"lf": "Alternative Birth Center", "freq": 1, "since": 1992}]}, {"lf": "artificial beta cell", "freq": 3, "since": 1984, "vars": [{"lf": "artificial beta cell", "freq": 3, "since": 1984}]}, {"lf": "American Biophysics Corporation", "freq": 3, "since": 2001, "vars": [{"lf": "American Biophysics Corporation", "freq": 3, "since": 2001}]}, {"lf": "adenine nucleotide binding cassette", "freq": 3, "since": 2000, "vars": [{"lf": "adenine nucleotide binding cassette", "freq": 2, "since": 2000}, {"lf": "adenine nucleotide-binding cassette", "freq": 1, "since": 2008}]}, {"lf": "Movement Assessment Battery for Children", "freq": 3, "since": 1998, "vars": [{"lf": "Movement Assessment Battery for Children", "freq": 3, "since": 1998}]}, {"lf": "Alcoholic Beverage Control", "freq": 3, "since": 1984, "vars": [{"lf": "Alcoholic Beverage Control", "freq": 2, "since": 1984}, {"lf": "alcohol beverage control", "freq": 1, "since": 1992}]}, {"lf": "The area between curves", "freq": 2, "since": 1992, "vars": [{"lf": "The area between curves", "freq": 2, "since": 1992}]}]}]