20776
The incorporation of radioactive ( 13 ) N atoms in the Al2O3 NPs allowed the study of the biodistribution of the metal oxide NPs in rats after intravenous administration via PET .
 Chemical: ( 13 ) N; Chemical: Al2O3; Chemical: metal oxide
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: ( 13 ) N; Chemical: Al2O3; Chemical: metal oxide