3280
Long - term variability was significantly greater for all density measures ( 0 . 7 % to 2 . 0 % ; p < 0 . 05 versus short - term ) and several structure measures : cortical thickness ( Ct . Th ) ( 3 . 4 % ; p < 0 . 01 versus short - term ) , cortical porosity ( Ct . Po ) ( 15 . 4 % ; p < 0 . 01 versus short - term ) , and trabecular thickness ( Tb . Th ) ( 2 . 2 % ; p < 0 . 01 versus short - term ) .
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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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