Pierre-and-Marie-Curie University

About: Pierre-and-Marie-Curie University is a education organization based out in Paris, France. It is known for research contribution in the topics: Population & Raman spectroscopy. The organization has 34448 authors who have published 56139 publications receiving 2392398 citations.

Bedside monitoring to adjust antiplatelet therapy for coronary stenting.

Abstract: In the monitoring group, high platelet reactivity in patients taking clopidogrel (34.5% of patients) or aspirin (7.6%) led to the administration of an additional bolus of clopidogrel, prasugrel, or aspirin along with glycoprotein IIb/IIIa inhibitors during the procedure. The primary end point occurred in 34.6% of the patients in the moni - toring group, as compared with 31.1% of those in the conventional-treatment group (hazard ratio, 1.13; 95% confidence interval (CI), 0.98 to 1.29; P = 0.10). The main secondary end point, stent thrombosis or any urgent revascularization, occurred in 4.9% of the patients in the monitoring group and 4.6% of those in the conventional- treatment group (hazard ratio, 1.06; 95% CI, 0.74 to 1.52; P = 0.77). The rate of major bleeding events did not differ significantly between groups. CONCLUSIONS This study showed no significant improvements in clinical outcomes with platelet- function monitoring and treatment adjustment for coronary stenting, as compared with standard antiplatelet therapy without monitoring. (Funded by Allies in Cardiovas -

Emergence of macroscopic directed motion in populations of motile colloids

Abstract: Populations of millions of colloidal rolling particles are shown to self-organize to achieve coherent motion; comparison between experiment and theory based on the microscopic interactions between these ‘rollers’ suggests that hydrodynamic interactions promote the emergence of the collective motion. Collective motion can be observed in the natural world at all scales, from flocking birds to schooling fish and swarming bacteria, but it is difficult to capture such behaviour in simple physical models. Artificial 'active matter' systems that show collective behaviour usually rely on collisions, making the description of interactions complex. Denis Bartolo and colleagues have now developed a unique experimental system consisting of self-propelled rolling spheres that self-organize and move in one direction in a crowd of millions. The spheres 'sense' each other via straightforward hydrodynamic interactions so that all parameters can be easily calculated and tuned. This work demonstrates that genuine physical interactions at the individual level are sufficient to set homogeneous active populations into stable directed motion. The system could be used to model natural collective motion and to design new self-organized materials and swarming microrobots. From the formation of animal flocks to the emergence of coordinated motion in bacterial swarms, populations of motile organisms at all scales display coherent collective motion. This consistent behaviour strongly contrasts with the difference in communication abilities between the individuals. On the basis of this universal feature, it has been proposed that alignment rules at the individual level could solely account for the emergence of unidirectional motion at the group level1,2,3,4. This hypothesis has been supported by agent-based simulations1,5,6. However, more complex collective behaviours have been systematically found in experiments, including the formation of vortices7,8,9, fluctuating swarms7,10, clustering11,12 and swirling13,14,15,16. All these (living and man-made) model systems (bacteria9,10,16, biofilaments and molecular motors7,8,13, shaken grains14,15 and reactive colloids11,12) predominantly rely on actual collisions to generate collective motion. As a result, the potential local alignment rules are entangled with more complex, and often unknown, interactions. The large-scale behaviour of the populations therefore strongly depends on these uncontrolled microscopic couplings, which are extremely challenging to measure and describe theoretically. Here we report that dilute populations of millions of colloidal rolling particles self-organize to achieve coherent motion in a unique direction, with very few density and velocity fluctuations. Quantitatively identifying the microscopic interactions between the rollers allows a theoretical description of this polar-liquid state. Comparison of the theory with experiment suggests that hydrodynamic interactions promote the emergence of collective motion either in the form of a single macroscopic ‘flock’, at low densities, or in that of a homogenous polar phase, at higher densities. Furthermore, hydrodynamics protects the polar-liquid state from the giant density fluctuations that were hitherto considered the hallmark of populations of self-propelled particles2,3,17. Our experiments demonstrate that genuine physical interactions at the individual level are sufficient to set homogeneous active populations into stable directed motion.

Development and validation of the HScore, a score for the diagnosis of reactive hemophagocytic syndrome.

Abstract: Objective Because it has no unique clinical, biologic, or histologic features, reactive hemophagocytic syndrome may be difficult to distinguish from other diseases such as severe sepsis or hematologic malignancies. This study was undertaken to develop and validate a diagnostic score for reactive hemophagocytic syndrome. Methods A multicenter retrospective cohort of 312 patients who were judged by experts to have reactive hemophagocytic syndrome (n = 162), were judged by experts to not have reactive hemophagocytic syndrome (n = 104), or in whom the diagnosis of reactive hemophagocytic syndrome was undetermined (n = 46) was used to construct and validate the reactive hemophagocytic syndrome diagnostic score, called the HScore. Ten explanatory variables were evaluated for their association with the diagnosis of hemophagocytic syndrome, and logistic regression was used to calculate the weight of each criterion included in the score. Performance of the score was assessed using developmental and validation data sets. Results Nine variables (3 clinical [i.e., known underlying immunosuppression, high temperature, organomegaly], 5 biologic [i.e., triglyceride, ferritin, serum glutamic oxaloacetic transaminase, and fibrinogen levels, cytopenia], and 1 cytologic [i.e., hemophagocytosis features on bone marrow aspirate]) were retained in the HScore. The possible number of points assigned to each variable ranged from 0–18 for known underlying immunosuppression to 0–64 for triglyceride level. The median HScore was 230 (interquartile range [IQR] 203–257) for patients with a positive diagnosis of reactive hemophagocytic syndrome and 125 (IQR 91–150) for patients with a negative diagnosis. The probability of having hemophagocytic syndrome ranged from 99% with an HScore of ≥250. Conclusion The HScore can be used to estimate an individual's risk of having reactive hemophagocytic syndrome. This scoring system is freely available online (http://saintantoine.aphp.fr/score/).