Fig. 2From: Progressive mechanical and structural changes in anterior cerebral arteries with Alzheimer’s diseaseMechanical response of ACAs from biaxial extension-inflation test at in vivo stretch ratio. a Axial force-pressure and b pressure-outer diameter measurements. c, d Circumferential and longitudinal stress vs. circumferential stretch ratio calculated using Eq. (3). e Tangent stiffness obtained from the circumferential stress vs. stretch curves in Fig. 2c for the control, early AD, and intermediate and advanced AD groups. Error bars in a–e displayed in one direction. f Tangent stiffness at 80 mmHg among the three groups presented in Fig. 2e. *p < 0.05Back to article page