| B - ORGANISMS 
 | Deleted term |  | Concept absorbed by | 
 
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| B01 - INVERTEBRATES 
 B03 - BACTERIA
 
 B04 - VIRUSES
 
 
 
 
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| C - DISEASES 
 | Deleted term |  | Concept absorbed by | 
 
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| C09 - OTORHINOLARYNGOLOGIC DISEASES 
 
 
 
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| D - CHEMICALS AND DRUGS 
 | Deleted term |  | Concept absorbed by | 
 
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| D02 - ORGANIC CHEMICALS 
 D06 - HORMONES, HORMONE SUBSTITUTES, AND HORMONE ANTAGONISTS
 
 D08 - ENZYMES, COENZYMES, AND ENZYME INHIBITORS
 
 
 
 
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| E - ANALYTICAL, DIAGNOSTIC AND THERAPEUTIC TECHNIQUES AND EQUIPMENT 
 | Deleted term |  | Concept absorbed by | 
 
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| E04 - SURGICAL PROCEDURES, OPERATIVE 
 
 
 
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| G - BIOLOGICAL SCIENCES 
 | Deleted term |  | Concept absorbed by | 
 
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| G01 - BIOLOGICAL SCIENCES 
 
 
 
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