. "139663" . "1"^^ . . "How Ageing is Reflected by Longitudinal Pretension in Abdominal Aorta" . . "I, P(GA106/08/0557), P(TA01010185), S, Z(MSM6840770012)" . . "1"^^ . . . . "How Ageing is Reflected by Longitudinal Pretension in Abdominal Aorta"@en . . . . "http://users.fs.cvut.cz/~hornyluk/files/How-aging-is-reflected-by-longitudinal-pretension-in-abdominal-aorta-PhD-Horny.pdf" . . . . . . . . . "Horn\u00FD, Luk\u00E1\u0161" . "[6083E2E1492F]" . "Studies on the influence of ageing on the longitudinal mechanical response of elastic arteries are rare, though longitudinal behaviour may have a significant effect on pressure pulse wave transmission. Longitudinal prestrain in physiological conditions ensures almost constant length of the artery during the cardiac cycle. This may not, however, be true in aged arteries. Our study was designed to elucidate how ageing is reflected in the longitudinal prestress, prestretch and pretension force. The study involved ten human samples (six female, four male) of the abdominal aorta with longitudinal prestretch determined in autopsy (age 47/12; prestretch 1.13/0.1; mean/SD). Cylindrical samples underwent a longitudinal elongation test in order to estimate the force necessary to attain the in situ length and to determine the corresponding axial stress (prestress). The elastic modulus was estimated employing a limiting chain extensibility model to describe the stress-strain relationship. It was found that pretension force, longitudinal prestress and prestretch are negatively correlated with age. The axial prestress decreases with age within one order of magnitude (from tens of kPa to units of kPa). The decreased longitudinal force necessary to obtain the in situ length suggested that the decrease in the prestress occurs not only due to the age-related increase in the cross-section area. Since elastin is the main constituent responsible bearing the prestretch, this suggests that the observed decrease in the longitudinal prestress and prestretch reflects ageing-induced damage to the elastin. Finally, constitutive modelling showed that limiting chain extensibility is a concept that is suitable for describing the ageing effect." . "RIV/68407700:21220/12:00193513" . . "Studies on the influence of ageing on the longitudinal mechanical response of elastic arteries are rare, though longitudinal behaviour may have a significant effect on pressure pulse wave transmission. Longitudinal prestrain in physiological conditions ensures almost constant length of the artery during the cardiac cycle. This may not, however, be true in aged arteries. Our study was designed to elucidate how ageing is reflected in the longitudinal prestress, prestretch and pretension force. The study involved ten human samples (six female, four male) of the abdominal aorta with longitudinal prestretch determined in autopsy (age 47/12; prestretch 1.13/0.1; mean/SD). Cylindrical samples underwent a longitudinal elongation test in order to estimate the force necessary to attain the in situ length and to determine the corresponding axial stress (prestress). The elastic modulus was estimated employing a limiting chain extensibility model to describe the stress-strain relationship. It was found that pretension force, longitudinal prestress and prestretch are negatively correlated with age. The axial prestress decreases with age within one order of magnitude (from tens of kPa to units of kPa). The decreased longitudinal force necessary to obtain the in situ length suggested that the decrease in the prestress occurs not only due to the age-related increase in the cross-section area. Since elastin is the main constituent responsible bearing the prestretch, this suggests that the observed decrease in the longitudinal prestress and prestretch reflects ageing-induced damage to the elastin. Finally, constitutive modelling showed that limiting chain extensibility is a concept that is suitable for describing the ageing effect."@en . "How Ageing is Reflected by Longitudinal Pretension in Abdominal Aorta"@en . . . . "ageing; aorta; arteriosclerosis; constitutive modelling; elastin; prestress; prestretch"@en . "21220" . "RIV/68407700:21220/12:00193513!RIV13-MSM-21220___" . "How Ageing is Reflected by Longitudinal Pretension in Abdominal Aorta" . . . .