27707
This systematic study was initiated as follow - up to personal anecdotal evidence acquired over more than 10 years by MH Bhattacharyya regarding PO ' s efficacy for treating burns .
 None
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
 Entities:  
Answer:
 None