2957
A fourth - generation ( G4 ) poly ( amidoamine ) ( PAMAM ) dendrimer ( G4 - NH2 ) has been used as a template to deliver nearly monodispersed catalyst nanoparticles to SiO2 / Si , Ti / Si , sapphire , and porous anodic alumina ( PAA ) substrates .
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Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Anatomy 
Text: {0} 
Answer:
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