14654
Our study showed that polarization of the nucleobases by K ( + ) enhanced electrostatic attraction between the base and ions .
 Chemical: nucleobases; Chemical: K ( + )
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: nucleobases; Chemical: K ( + )