Fluidic diode for critical two-phase flows

A fluidic diode for critical two-phase flows is developed and validated for the boiling water reactor KERENA. To investigate the fluidic behavior of this fluidic diode, a 3D cavitation model accounting for non-equilibrium and quality effects is developed. This model is the first application of the stochastic-field method to multi-phase flow. Validation of this model indicates that agreement with experimental results is obtained for very differing applications with a fixed set of model constants

Spontaneous migration of cellular aggregates from giant keratocytes to running spheroids

Despite extensive knowledge on the mechanisms that drive singlecell migration, those governing the migration of cell clusters, as occurring during embryonic development and cancer metastasis,remain poorly understood. Here, we investigate the collective migration of cell on adhesive gels with variable rigidity, using 3D cellular aggregates as a model system. After initial adhesion to the substrate, aggregates spread by expanding outward a cell monolayer, whose dynamics is optimal in a narrowrange of rigidities. Fast expansion gives rise to the accumulation of mechanical tension that leads to the rupture of cell–cell contacts and the nucleation of holes within the monolayer, which becomes unstable and undergoes dewetting like a liquid film. This leads to a symmetry breaking and causes the entire aggregate to move as a single entity. Varying the substrate rigidity modulates the extent of dewetting and induces different modes of aggregate motion: “giant keratocytes,” where the lamellipodium is a cell monolayer that expands at the front and retracts at the back; “penguins,” characterized by bipedal locomotion; and “running spheroids,” for nonspreading aggregates. We characterize these diverse modes of collectivemigration by quantifying the flows and forces that drive them, andwe unveil the fundamental physical principles that govern these behaviors, which underscore the biological predisposition of living material to migrate, independent of length scale

Glycolipid Biosurfactant as Multilamellar Vesicular Drug Carriers

Microbial amphiphiles, known as biosurfactants, are molecules obtained fermentation of yeasts or bacteria. Biobased and biodegradable, they have been historically developed for detergency formulations, whereas more recent work has shown their interest as antimicrobials or depollutants. However, their self-assembly properties and their interactions with macromolecules suggest a broader potential of applications. Drug encapsulation for anti-cancer purposes is a well-known application of lipids such as phospholipids. In this study, for the first time, a drug delivery system based on microbial amphiphiles is designed and tested against human cervical carcinoma HeLa cells. For this purpose, multilamellar wall vesicles (MLWV) consisting of microbial glucolipid (GC) amphiphiles and polylysine (PLL), attracted by electrostatic interactions, have been synthesized. Curcumin, a highly lipophilic molecule, has been used as natural drug model to evaluate the GCPLL MLWVs as potential nanocarrier to specifically deliver drugs into cancer cells. The curcumin loaded MLWVs uptake measured by flow cytometry is much higher in Hela cells (50%) compared to NHDF (35%) and THP-1 derived macrophages (20%). This uptake is correlated to cytotoxicity as cell viability only decreases for Hela cells (by 50%). A dedicated mechanistic study shows that the cytotoxic effect is based on MLWV fusion with the cell membrane and the curcumin release within the cellular cytoplasm. Taken together, these results demonstrate that microbial amphiphiles can be used to develop engineered drug delivery system to efficiently target cancer cells

Glycolipid Biosurfactant as Multilamellar Vesicular Drug Carriers

Microbial amphiphiles, known as biosurfactants, are molecules obtained fermentation of yeasts or bacteria. Biobased and biodegradable, they have been historically developed for detergency formulations, whereas more recent work has shown their interest as antimicrobials or depollutants. However, their self-assembly properties and their interactions with macromolecules suggest a broader potential of applications. Drug encapsulation for anti-cancer purposes is a well-known application of lipids such as phospholipids. In this study, for the first time, a drug delivery system based on microbial amphiphiles is designed and tested against human cervical carcinoma HeLa cells. For this purpose, multilamellar wall vesicles (MLWV) consisting of microbial glucolipid (GC) amphiphiles and polylysine (PLL), attracted by electrostatic interactions, have been synthesized. Curcumin, a highly lipophilic molecule, has been used as natural drug model to evaluate the GCPLL MLWVs as potential nanocarrier to specifically deliver drugs into cancer cells. The curcumin loaded MLWVs uptake measured by flow cytometry is much higher in Hela cells (50%) compared to NHDF (35%) and THP-1 derived macrophages (20%). This uptake is correlated to cytotoxicity as cell viability only decreases for Hela cells (by 50%). A dedicated mechanistic study shows that the cytotoxic effect is based on MLWV fusion with the cell membrane and the curcumin release within the cellular cytoplasm. Taken together, these results demonstrate that microbial amphiphiles can be used to develop engineered drug delivery system to efficiently target cancer cells

Multilamellar Nanovectors composed of Microbial Glycolipid-Polylisine Complexes for Drug Encapsulation

This study addresses the potential use of single-glucose microbial amphiphiles as phospholipid-free drug carriers. Microbial amphiphiles, also known as biosurfactants, are molecules obtained from the fermentation of bacteria, fungi or yeast and largely studied for their antimicrobial, cleaning or anti-pollution potential. However, recent understanding of their self-assembly properties combined to their interactions with macromolecules suggest broader potential applications, one being the phospholipid-free conception of drugs. In this study, we want to demonstrate that this class of bio-based molecules can be directly used to design colloidally-stable vesicular carriers for hydrophobic drugs, without employing phospholipid supports, and that the actives can be delivered to human cells. In this study, multilamellar wall vesicles (MLWVs) have been synthesised using a microbial glycolipid amphiphile and polylysine, held together by electrostatic attractive interactions. Curcumin, a highly lipophilic molecule, was used as natural drug model to evaluate the present colloidal system as potential nanocarrier. The cell uptake of the curcumin-loaded nanocarriers was significantly higher for HeLa cells (50 %) compared to Normal Human Dermal Fibroblasts (35 %) and to THP-1 derived macrophages (20 %). The cytotoxic effect of delivered curcumin or other pharmaceuticals (Doxorubicin, Docetaxel, Paclitaxel) was higher in HeLa cells as the cell viability was reduced by 50 %

Gaps in the management of food‐induced anaphylaxis reactions at school

International audienc

Gaps in the management of food‐induced anaphylaxis reactions at school

International audienc

Dossier : L'eau dans la ville antique

This work proposes a Multibody Structure from Motion (MSfM) algorithm for moving object reconstruction that incorporates instance-aware semantic segmentation and multiple view geometry methods. The MSfM pipeline tracks two-dimensional object shapes on pixel level to determine object specific feature correspondences, in order to reconstruct 3D object shapes as well as 3D object motion trajectories