25321
METHODS : The sample consisted of 30 non - smokers and 16 smokers , who completed an initial assessment , followed on a separate day by a laboratory assessment of PPI prior to and following each of two intravenous nicotine infusions .
 Chemical: nicotine
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: nicotine