528
There was a direct proportional relationship between the spiral artery flow and the pressure difference between the spiral artery and the amniotic fluid ; the pressure difference per flow ( the resistance of the cotyledonary unit ) was found to be 1 - - 3 mm Hg . ml - 1 . min ( 8 - - 24kPa . ml - 1 . s ) .
 None
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: GENE 
Text: {0} 
Answer:
 None