Thierry Savin

Learn More
Particle tracking techniques are often used to assess the local mechanical properties of cells and biological fluids. The extracted trajectories are exploited to compute the mean-squared displacement that characterizes the dynamics of the probe particles. Limited spatial resolution and statistical uncertainty are the limiting factors that alter the accuracy(More)
The developing vertebrate gut tube forms a reproducible looped pattern as it grows into the body cavity. Here we use developmental experiments to eliminate alternative models and show that gut looping morphogenesis is driven by the homogeneous and isotropic forces that arise from the relative growth between the gut tube and the anchoring dorsal mesenteric(More)
The role of a finite exposure time sigma on measuring rheological properties using microrheology techniques is theoretically investigated. We concentrate on studying fluid models displaying a plateau in the mean-squared displacement (MSD) of the embedded probe particle. A model is developed to compare the resulting experimentally measured MSD of the(More)
Percutaneous transluminal balloon catheter aortic valvuloplasty (PTAV) was carried out in three elderly patients with acquired severe aortic valve stenosis. Transvalvular systolic pressure gradient was considerably decreased at the end of the procedure, during which there were no complications. Increased valve opening was confirmed by angiography and(More)
Percutaneous transluminal balloon valvuloplasty was attempted in 92 adult patients with severe calcific aortic stenosis. The mean age was 75 +/- 11 years (range 38 to 91) and 35 patients were more than 80 years old. Most of the patients were severely disabled; 66 were in New York Heart Association functional class III or IV, 27 had syncopal attacks and 21(More)
The efficacy, morbidity, and 1-year follow-up of balloon aortic valvuloplasty in patients with low ejection fraction (less than 40%) were studied on a consecutive series of 55 patients (mean age, 77 years) treated from September 1985 to February 1987. Because of their age (20 patients greater than 80 years old), poor left ventricular function, and(More)
Video microscopy can be used to simultaneously track several microparticles embedded in a complex material. The trajectories are used to extract a sample of displacements at random locations in the material. From this sample, averaged quantities characterizing the dynamics of the probes are calculated to evaluate structural and/or mechanical properties of(More)
Aortic valvular dilatation with a balloon catheter was performed in 44 patients, 20 men and 24 women, most of whom were very elderly (average age 77 years). The indication for valvular replacement had not been retained in these cases because of surgical contra-indications or a very high operative risk and in 3 cases because of patient refusal. Twenty-nine(More)
Hydrogels formed from the self-assembly of oligopeptides are being extensively studied for biomedical applications. The kinetics of their gelation, as well as a quantitative description of the forces controlling the rate of assembly has not yet been addressed. We report here the use of multiple particle tracking to measure the self-assembly kinetics of the(More)
Using computational modeling, we investigate the mechanical properties of polymeric materials composed of coiled chains, or "globules", which encompass a folded secondary structure and are cross-linked by labile bonds to form a macroscopic network. In the presence of an applied force, the globules can unfold into linear chains and thereby dissipate energy(More)