Expression profiling of laser-microdissected intrapulmonary arteries in hypoxia-induced pulmonary hypertension

BACKGROUND: Chronic hypoxia influences gene expression in the lung resulting in pulmonary hypertension and vascular remodelling. For specific investigation of the vascular compartment, laser-microdissection of intrapulmonary arteries was combined with array profiling. METHODS AND RESULTS: Analysis was performed on mice subjected to 1, 7 and 21 days of hypoxia (FiO(2 )= 0.1) using nylon filters (1176 spots). Changes in the expression of 29, 38, and 42 genes were observed at day 1, 7, and 21, respectively. Genes were grouped into 5 different classes based on their time course of response. Gene regulation obtained by array analysis was confirmed by real-time PCR. Additionally, the expression of the growth mediators PDGF-B, TGF-β, TSP-1, SRF, FGF-2, TIE-2 receptor, and VEGF-R1 were determined by real-time PCR. At day 1, transcription modulators and ion-related proteins were predominantly regulated. However, at day 7 and 21 differential expression of matrix producing and degrading genes was observed, indicating ongoing structural alterations. Among the 21 genes upregulated at day 1, 15 genes were identified carrying potential hypoxia response elements (HREs) for hypoxia-induced transcription factors. Three differentially expressed genes (S100A4, CD36 and FKBP1a) were examined by immunohistochemistry confirming the regulation on protein level. While FKBP1a was restricted to the vessel adventitia, S100A4 and CD36 were localised in the vascular tunica media. CONCLUSION: Laser-microdissection and array profiling has revealed several new genes involved in lung vascular remodelling in response to hypoxia. Immunohistochemistry confirmed regulation of three proteins and specified their localisation in vascular smooth muscle cells and fibroblasts indicating involvement of different cells types in the remodelling process. The approach allows deeper insight into hypoxic regulatory pathways specifically in the vascular compartment of this complex organ

Experimental investigation of the dielectric barrier discharge using design of experiments

AbstractMany experimental and numerical studies were devoted to Dielectric Barrier Discharge (DBD) in air, but no mathematical models were proposed, either for current or for power. As they depend on several parameters, it is difficult to find a formula that considers many factors. The aim of this paper is first to make a brief comparison between surface and volume DBD, and second to model the current and power of a DBD in a “multipoints-plane” electrode system, using the methodology of experimental design. Three factors were considered: inter-electrode distance, distance between adjacent points, and thickness of the glass dielectric barrier. A double Composite Centred Faces experimental design (CCF) was carried out. The obtained results made it possible to propose mathematical models and, therefore to study interactions between various factors

New separation technique of metal/polymer granular materials using an electrostatic sorting device

International audienceElectric curtain consisting of a series of parallel electrodes and powered by a polyphase voltage has been extensively used for transporting and/or separating micronized insulating particles. The aim of this work is to investigate a new electrostatic sorting device (ESD) similar to an inter-digitated electrode configuration for the separation of millimeter-size metal/plastic particles, based on the electro-adhesive force applied on the metal granules. The granular mixture is deposited on a dielectric cylinder covered by two-phase inter-digitated electrodes and rotating at a controlled speed. An experimental analysis was carried out to analyze the influence of various factors on the performance of this new separator. The obtained results showed that the new separator makes it possible to obtain high-purity products; its performance depends on several factors such as the level of the applied voltage, the signal frequency and the rotation speed of the drum

Analysis of a novel insulating conveyor-belt tribo-electrostatic separator for highly humid granular products

International audienceThe objective of this work is to describe a new configuration of tribo-electrostatic separator equipped with an insulating rubber belt conveyor, to facilitate the processing particles saturated with moisture. The insulating belt is continually charged by corona discharge produced by a fine-wire electrode, placed at a distance of 5 mm above it. The experiments were carried out under conditions of high humidity using samples of HDPE and PP particles. Separation experiments have shown that when the belt is charged by corona, more than 50% of the particles were separated with purity higher than 95%