Lumen shape reconstruction using a soft robotic balloon catheter and electrical impedance tomography

Incorrectly sized balloon catheters can lead to increased post-surgical complications, yet even with preoperative imaging, correct selection remains a challenge. With limited feedback during surgery, it is difficult to verify correct deployment. We propose the use of integrated impedance measurements and Electrical Impedance Tomography (EIT) imaging to assess the deformation of the balloon and determine the size and shape of the surrounding lumen. Previous work using single impedance measurements, or pressure data and analytical models, whilst demonstrating high sizing accuracy, have assumed a circular cross section. Here we extend these methods by adding a multitude of electrodes to detect elliptical and occluded lumen and obtain EIT images to localise deformations. Using a 14 Fr (5.3 mm) catheter as an example, numerical simulations were performed to find the optimal electrode configuration of two rings of 8 electrodes spaced 10 mm apart. The simulations predicted that the maximum detectable aspect ratio decreased from 0.9 for a 14mm balloon to 0.5 at 30mm. The sizing and ellipticity detection results were verified experimentally. A prototype robotic balloon catheter was constructed to automatically inflate a compliant balloon while simultaneously recording EIT and pressure data. Data were collected in experiments replicating stenotic vessels with an elliptical and asymmetrical profile, and the widening of a lumen during angioplasty. After calibration, the system was able to correctly localise the occlusion and detect aspect ratios of 0.75. EIT images further localised the occlusion and visualised the dilation of the lumen during balloon inflation

Catalytic combustion of polycyclic aromatic hydrocarbons (PAH) over zeolite type catalysts : effect of Si/Al ratio, structure and acidity

SSCI-VIDE+ATARI+JSO:PGEInternational audiencePAHs show adverse health effects. For instance, benzo(a)pyrene is classified as carcinogenic by IARC. Therefore, at the international level, many countries have committed themselves to minimizing air emissions through the Aarhus Protocol on POPs which was signed in 1998 under the Geneva Long Range Transboundary Air Pollution Convention. At the French level, emission limit values for PAHs have been introduced in a recent regulation on combustion plants with a thermal input higher than 20 MWth (Ministerial Decree of 26 August 2013). Catalytic oxidation is one of the most promising technologies to reduce the emissions of air pollutants [1]. Metal oxides or supported noble metals methods are the most investigated catalysts for the destruction of organic pollutants. Acid zeolites (protonic forms) have been considered as effective cheap alternative catalysts to metal oxides for hydrocarbons oxidation [2]. Catalytic performances of these zeolites were associated with the presence of Bronsted acid sites. In this work, the removal of 1-methyl naphthalene (1-MN), a model compound representative of PAH, by catalytic combustion in the presence of steam is investigated. The behavior of various acidic zeolites and Pd exchanged acidic zeolites towards the gas-phase catalytic oxidation of 1-MN is studied. The effect of some parameters on 1-MN oxidation is studied: zeolite structure, Lewis and Bronsted acidity, and Si/Al ratio and Pd loading. The catalytic performance of the zeolitic catalysts is compared to that of reference Pd catalysts supported on SiO2 and Al2O3

Catalytic combustion of polycyclic aromatic hydrocarbons (PAH) over zeolite type catalysts: effect of Si/Al ratio, structure and acidity

SSCI-VIDE+ATARI+JSO:PGEInternational audienceNon

Catalytic combustion of polycyclic aromatic hydrocarbons (PAH) over zeolite type catalysts: effect of Si/Al ratio, structure and acidity

SSCI-VIDE+ATARI+JSO:PGEInternational audienceNon

Maturation of Rhodococcus equi-containing vacuoles is arrested after completion of the early endosome stage.

Rhodococcus equi is a facultative intracellular bacterium that can cause bronchopneumonia in foals and AIDS patients. Here, we have analyzed R. equi-containing vacuoles (RCVs) in murine macrophages by confocal laser scanning microscopy, by transmission electron microscopy and by immunochemistry upon purification. We show that RCVs progress normally through the early stages of phagosome maturation acquiring PI3P, early endosome antigen-1, and Rab5, and loosing all or much of them within minutes. Although mature RCVs possess the normally late endocytic markers, lysosome-associated membrane proteins, lysobisphosphatidic acid and Rab7, they lack other hallmark features of late endocytic organelles such as possession of cathepsin D, acid beta-glucuronidase, proton-pumping ATPase and the ability to fuse with prelabeled lysosomes. Bacterial strains possessing a virulence-associated plasmid maintain a nonacidified compartment for 48 h, whereas isogenic strains lacking such plasmids acidify progressively. In summary, RCVs represent a novel phagosome maturation stage positioned after completion of the early endosome stage and before reaching a fully mature late endosome compartment. In addition, vacuole biogenesis can be influenced by bacterial plasmids