In the sentence extracted from biomedical literature, identify all the chemical entities. The required answer format is the same sentence with HTML <span> tags to mark up specific entities. 
### Entity Markup Guides:
Use <span class="chemical"> to denote a chemical.

### Input Text: End - systolic left ventricular posterior wall dimension at the 5 - micrograms / kg per min dobutamine infusion for the doxorubicin - treated group was 14 . 1 + / - 2 . 4 mm versus 19 . 3 + / - 2 . 6 mm for control subjects ( p less than 0 . 01 ) . ( ABSTRACT TRUNCATED AT 250 WORDS )
### Output Text:
End - systolic left ventricular posterior wall dimension at the 5 - micrograms / kg per min <span class="chemical">dobutamine</span> infusion for the <span class="chemical">doxorubicin</span> - treated group was 14 . 1 + / - 2 . 4 mm versus 19 . 3 + / - 2 . 6 mm for control subjects ( p less than 0 . 01 ) . ( ABSTRACT TRUNCATED AT 250 WORDS ) 