Fig. 3From: The pulmonary toxicity of carboxylated or aminated multi-walled carbon nanotubes in mice is determined by the prior purification methodLactate dehydrogenase (LDH) activity and total protein in BAL fluid at 3 or 60 days after exposure to a low and high dose of purified and functionalized MWCNTs. a LDH activity. b Total protein. Statistically significant difference to the vehicle control: *** P < 0.001, ** P < 0.01, * P < 0.05, the parent NC7000 sample: ^^^ P < 0.001, ^^ P < 0.01, or to the chemically-purified sample CP7000: ### P < 0.001, # P < 0.05Back to article page