20774
We present a simple and straightforward method for the direct proton beam activation of synthetic or commercially available aluminum oxide NPs ( Al2O3 NPs ) via the ( 16 ) O ( p , alpha ) ( 13 ) N nuclear reaction in order to assess their biological fate using positron emission tomography ( PET ) .
 Chemical: aluminum oxide; Chemical: Al2O3; Chemical: ( 16 ) O; Chemical: ( 13 ) N
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: aluminum oxide; Chemical: Al2O3; Chemical: ( 16 ) O; Chemical: ( 13 ) N