title: Low Density Lipoprotein and Non-Newtonian Oscillating Flow Biomechanical Parameters for Normal Human Aorta.
abstract: BACKGROUND
  The temporal variation of the hemodynamic mechanical parameters during cardiac pulse wave is considered as an important atherogenic factor. Applying non-Newtonian blood molecular viscosity simulation is crucial for hemodynamic analysis. Understanding low density lipoprotein (LDL) distribution in relation to flow parameters will possibly spot the prone to atherosclerosis aorta regions.
  
  
  METHODS
  The biomechanical parameters tested were averaged wall shear stress (AWSS), oscillatory shear index (OSI) and relative residence time (RRT) in relation to the LDL concentration. Four non-Newtonian molecular viscosity models and the Newtonian one were tested for the normal human aorta under oscillating flow. The analysis was performed via computational fluid dynamic.
  
  
  RESULTS
  Tested viscosity blood flow models for the biomechanical parameters yield a consistent aorta pattern. High OSI and low AWSS develop at the concave aorta regions. This is most noticeable in downstream flow region of the left subclavian artery and at concave ascending aorta. Concave aorta regions exhibit high RRT and elevated LDL. For the concave aorta site, the peak LDL value is 35.0% higher than its entrance value. For the convex site, it is 18.0%. High LDL endothelium regions located at the aorta concave site are well predicted with high RRT.
  
  
  CONCLUSIONS
  We are in favor of using the non-Newtonian power law model for analysis. It satisfactorily approximates the molecular viscosity, WSS, OSI, RRT and LDL distribution. Concave regions are mostly prone to atherosclerosis. The flow biomechanical factor RRT is a relatively useful tool for identifying the localization of the atheromatic plaques of the normal human aorta.
authors.affiliation: Department of Civil Engineering, Fluid Mechanics Division, School of Engineering, Demokrition University of Thrace, Vas. Sofias 12, 67100 Xanthi, Greece; These authors contributed equally to this work.
authors.forename: Johannes V
authors.initials: JV
authors.lastname: Soulis
authors.affiliation: Department of Civil Engineering, Fluid Mechanics Division, School of Engineering, Demokrition University of Thrace, Vas. Sofias 12, 67100 Xanthi, Greece; These authors contributed equally to this work.
authors.forename: Dimitrios K
authors.initials: DK
authors.lastname: Fytanidis
authors.affiliation: Department of Civil Engineering, Fluid Mechanics Division, School of Engineering, Demokrition University of Thrace, Vas. Sofias 12, 67100 Xanthi, Greece; These authors contributed equally to this work.
authors.forename: Olga P
authors.initials: OP
authors.lastname: Lampri
authors.affiliation: The 1st Cardiology Department, Cardiovascular Engineering and Atherosclerosis Laboratory, AHEPA University Hospital, Medical School, Aristotle University of Thessaloniki, Thessaloniki, Kiriakidi 1, 54621 Thessaloniki, Greece; These authors contributed equally to this work.
authors.forename: George D
authors.initials: GD
authors.lastname: Giannoglou
keywords: Low density lipoprotein; Non-Newtonian models; Normal human aorta; Oscillatory shear index; Relative residence time