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Physique de systèmes biologiques
(18) Production(s) de l'année 2019
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Spinning Drop Dynamics in Miscible and Immiscible Environments
Auteur(s): Carbonaro A., Cipelletti L., Truzzolillo D.
(Article) Publié:
Langmuir, vol. 35 p.11330-11339 (2019)
Texte intégral en Openaccess :
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4D compressive sensing holographic microscopy imaging of small moving objects
Auteur(s): Brodoline A., Rawat Nitin, Alexandre D., Cubedo Nicolas, Gross M.
(Article) Publié:
Optics Letters, vol. 44 p.2827 (2019)
Texte intégral en Openaccess :
Ref HAL: hal-02189448_v1
DOI: 10.1364/OL.44.002827
WoS: 000469838100055
Exporter : BibTex | endNote
11 Citations
Résumé: We show that compressive sensing (CS) calculations are very ecient to reconstruct in 3D sparse objects whose 2D hologram has been recorded by digital holographic microscopy. The method is well adapted to image small scattering objects moving within a larger motionless object. This situation corresponds to red blood cells (RBCs) circulating in the vascular system of a zebrash (Danio rerio) larva. RBCs positions are imaged in 3D from a single hologram, while the RBCs trajectories, i.e. the perfused blood vessels, are imaged from a sequence of holograms. With respect to previous work (Donnarumma et al., Opt. express, 24, 26887, 2016), we get a gain of ∼ 500 in calculation speed.
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Interfacial behavior of plant proteins
Auteur(s): Banc A., Poirier A., Stocco A., In M., Ramos L.
Conference: Edible Soft Matter (Le Mans, FR, 2019-04-18)
Ref HAL: hal-02130225_v1
Exporter : BibTex | endNote
Résumé: Challenges of public health and sustainable development require replacing in food products animal proteins by plant proteins. In this optics, it is crucial to understand the structure and kinetic of formation of a film of plant proteins in order to improve the control of emulsions and foams stabilized by these proteins.In this talk we will present experimental results on the behaviour interfacial properties of wheat gluten, sunflower and rapeseed proteins at liquid interfaces. Thanks to a combination of tensiometry, dilatational rheology and ellipsometry, rational physical pictures of the dynamics of the interfacial properties are achieved, for the various proteins and at both air/water and oil/water interfaces. For gluten proteins, a time-concentration superposition of the data is evidenced whatever the subphase concentration, which reveals that the kinetics of protein adsorption at the interface is dominated by bulk diffusion. We propose a consistent physical picture of the multistep diffusion-controlled irreversible adsorption of the gliadin proteins at an air/water interface, and evidence surface-induced conformational changes of the proteins followed by film gelation [1]. Sunflower and rapeseed proteins by contrast do not reorganize once adsorbed at an interface and display a simpler dynamics of film formation. In addition the failure at high concentration of the time-concentration superposition of the tensiometry and viscoelastic data strongly suggest a surface-induced aggregation process, which we confirm with turbidity measurements. By quantitatively comparing the surface pressure dependence viscoelasticity of the various interfaces, we hightlight the crucial role on the behavior of plant proteins at liquid interfaces of the solvent quality and of the protein softness, that is discussed in regard to the protein structure.
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Coupling Space-Resolved Dynamic Light Scattering and Rheometry to Investigate Heterogeneous Flow and Nonaffine Dynamics in Glassy and Jammed Soft Matter
Auteur(s): Pommella A., Philippe A. M., Phou T., Ramos L., Cipelletti L.
(Article) Publié:
Physical Review Applied, vol. 11 p.034073 (2019)
Texte intégral en Openaccess :
Ref HAL: hal-03029048_v1
Ref Arxiv: 1809.00506
DOI: 10.1103/PhysRevApplied.11.034073
WoS: 000462959200003
Ref. & Cit.: NASA ADS
Exporter : BibTex | endNote
2 Citations
Résumé: We present a new light scattering setup coupled to a commercial rheometer operated in the plate-plate geometry. The apparatus allows the microscopic dynamics to be measured, discriminating between the contribution due to the affine deformation and additional mechanisms, such as plasticity. Light backscattered by the sample is collected using an imaging optical layout, thereby allowing the average flow velocity and the microscopic dynamics to be probed with both spatial and temporal resolution. We successfully test the setup by measuring the Brownian diffusion and flow velocity of diluted colloidal suspensions, both at rest and under shear. The potentiality of the apparatus are explored in the startup shear of a biogel. For small shear deformations, $\gamma \le 2\%$, the rheological response of the gel is linear. However, striking deviations from affine flow are seen from the very onset of deformation, due to temporally and spatially heterogeneous rearrangements bearing intriguing similarities with a stick-slip process.
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Bronchial Epithelial Calcium Metabolism Impairment in Smokers and Chronic Obstructive Pulmonary Disease Decreased ORAI3 Signaling
Auteur(s): Petit Aurelie, Knabe Lucie, Khelloufi Kamel, Jory M., Gras Delphine, Cabon Yann, Begg Malcolm, Richard Sylvain, Massiera G., Chanez Pascal, Vachier Isabelle, Bourdin Arnaud
(Article) Publié:
American Journal Of Respiratory Cell And Molecular Biology, vol. 61 p.501-511 (2019)
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Inferring data on cilia spatiotemporal coordination through bronchial epithelium imaging
Auteur(s): Jory M., Fort Aurélie, Casanellas Vilageliu L., Vachier Isabelle, Bourdin Arnaud, Massiera G.
(Affiches/Poster)
Physics and Physiology of Motile Cilia (Bad Honnef, DE), 2019-01-27
Ref HAL: hal-02061766_v1
Exporter : BibTex | endNote
Résumé: The mucociliary function of the bronchial epithelium ensures the continuous clearance of the respiratory system. This function relies on two main elements: mucus properties and cilia beating coordination. We work on high speed optical microscopy videos of Human bronchial epithelium from ALI (Air-liquid interface) cultures. We present here a technique based on the tracking of each cilium and on the spatiotemporal analysis of the obtained trajectories. To relate each cilium to its corresponding cell, a clustering method is used. The spatiotemporal coordination can than be quantified both, inside and in-between ciliated cells. In addition the physical parameters can be mapped to observe the heterogeneity of the cilia activity and compare different pathologies.
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