20838
For example , GdIO nanoparticles with a diameter of ~ 4 . 8 nm exhibited a high r1 relaxivity of 7 . 85 mM ( - 1 ) . S ( - 1 ) and a low r2 / r1 ratio of 5 . 24 .
 GdIO
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 GdIO