2264
Average lacunar densities ( +/- standard deviation ) from the anterior , posterior , medial and lateral regions were 27 , 169 +/- 1935 , 26 , 3643 +/- 1262 , 37 , 521 +/- 6416 and 33 , 972 +/- 2513 lacunae per mm ( 3 ) of bone tissue , respectively .
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Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
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