Sun, 20 Jul 2008 13:37:32 BST CiteULike: matthewhflamm aggregation http://www.citeulike.org/user/matthewhflamm/tag/aggregation CiteULike.org en-gb Copyright © 2004-2008 citeulike.org http://www.citeulike.org/user/matthewhflamm/article/2683066 <i>Proceedings of the National Academy of Sciences, Vol. 103, No. 46. (14 November 2006), pp. 17164-17169.</i><br /><br />Mural thrombi are composed dominantly of platelets and develop under a blood flow. Portions can break off and are carried in the blood flow as emboli. Thrombus growth rates are affected by the velocity of the blood flow, but they do not simply increase with it, they exhibit a maximum, with subsequent decrease. Whereas this variation indicates an interaction of biochemical and physical processes, studies have concentrated widely on understanding only the biochemical processes. Here we show results of simulation of thrombus formation in 3D flows by accounting for the movements of individual platelets. Each platelet follows prescribed rules for interactions while the local flow around the thrombus continuously adjusts to the growing structure of the thrombus, also when embolization occurs. With an activation delay time assigned to each platelet we demonstrate the dependence of thrombus growth rate on blood velocity as found experimentally by Begent and Born [Begent N, Born GV (1970) Nature 227:926-930]. With activated platelets having mutual tensile action sustainable up to a prescribed distance we achieve thrombus growth faster than with shorter maximum distances that make a thrombus less porous; when the prescribed maximum distance is large enough the thrombus shape is not like a "hill" but like a "carpet." We find that thrombus growth rate is enhanced by modest pulsatility but less so when pulsations are amplified in part because of more embolization. 10.1073/pnas.0608546103 Blood flow velocity effects and role of activation delay time on growth and form of platelet thrombi Igor Pivkin Peter Richardson George Karniadakis doi:10.1073/pnas.0608546103 Proceedings of the National Academy of Sciences, Vol. 103, No. 46. (14 November 2006), pp. 17164-17169. 2008-04-17T17:52:05-00:00 2006 Proceedings of the National Academy of Sciences 103 46 17164 17169 aggregation computational_simulation convection platelet