Utilisation d'un laser à argon ionisé en endoscopie digestive : photocoagulation des lésions hémorragiques

An endoscopic laser photocoagulation has been developed by the authors. The purpose of this system is to induce through endoscopy the hemostasis of bleeding lesions in the digestive tract. The blue-green light of the argon laser in transmitted by an optic fiber. The various parameters involved in the intensity of the photocoagulation have been determined by an experimental study on animals. After having been officially approved by the French Health Ministry, the first patients have been treated. From the first results the laser coagulation appears to be a non dangerous and effective method of endoscopic treatment of the digestive hemorrhages.Les auteurs ont fabriqué un photocoagulateur endoscopique par rayon laser. Cet appareil est destiné à induire par voie endoscopique l'hémostase des lésions digestives hémorragiques. Il est réalisé avec un laser à argon ionisé dont le faisceau est transmis par fibre optique. Une étude expérimentale a permis de déterminer les paramètres qui règlent l'intensité de la photocoagulation. Une fois obtenue l'autorisation ministérielle de la mise à l'essai clinique, les auteurs ont pu commencer à traiter des malades. Au vu des premiers résultats, il semble que la photocoagulation par voie endoscopique soit une méthode efficace et sûre de traitement des hémorragies digestives

Large-Area Oxidized Phosphorene Nanoflakes Obtained by Electrospray for Energy-Harvesting Applications

Bidimensional (2D) materials are nowadays being developed as outstanding candidates for electronic and optoelectronic components and devices. Targeted applications include sensing, energy conversion, and storage. Phosphorene is one of the most promising systems in this context, but its high reactivity under atmospheric conditions and its small-area/lab-scale deposition techniques have hampered the introduction of this material in real-world applications so far. However, phosphorene oxides in the form of low-dimensional structures (2D POx) should behave as an electroresponsive material according to recent theoretical studies. In the present work, we introduce electrospraying for the deposition of stoichiometric and large-area 2D POx nanoflakes starting from a suspension of liquid-phase-exfoliated phosphorene. We obtained 2D POx nanostructures with a mean surface area two orders of magnitude larger than phosphorene structures obtained with standard mechanical and liquid exfoliation techniques. X-ray spectroscopy and high-resolution electron microscopy confirmed the P2O5-like crystallographic structure of the electrosprayed flakes. Finally, we experimentally demonstrated for the first time the electromechanical responsivity of the 2D P2O5 nanoflakes, through piezoresponse force microscopy (PFM). This work sheds light on the possible implementation of phosphorus oxide-based 2D nanomaterials in the value chain of fabrication and engineering of devices, which might be easily scaled up for energy-harvesting/conversion applications

Lenalidomide restrains motility and overangiogenic potential of bone marrow endothelial cells in patients with active multiple myeloma.

Purpose: To determine the in vivo and in vitro antiangiogenic power of lenalidomide, a "lead compound" of IMiD immunomodulatory drugs in bone marrow (BM) endothelial cells (EC) of patients with multiple myeloma (MM) in active phase (MMEC). Experimental Design: The antiangiogenic effect in vivo was studied using the chorioallantoic membrane (CAM) assay. Functional studies in vitro (angiogenesis, "wound" healing and chemotaxis, cell viability, adhesion, and apoptosis) were conducted in both primary MMECs and ECs of patients with monoclonal gammopathies (MGUS) of undetermined significance (MGEC) or healthy human umbilical vein endothelial cells (HUVEC). Real-time reverse transcriptase PCR, Western blotting, and differential proteomic analysis were used to correlate morphologic and biological EC features with the lenalidomide effects at the gene and protein levels. Results: Lenalidomide exerted a relevant antiangiogenic effect in vivo at 1.75 mu mol/L, a dose reached in interstitial fluids of patients treated with 25 mg/d. In vitro, lenalidomide inhibited angiogenesis and migration of MMECs, but not of MGECs or control HUVECs, and had no effect on MMEC viability, apoptosis, or fibronectin-and vitronectin-mediated adhesion. Lenalidomide-treated MMECs showed changes in VEGF/VEGFR2 signaling pathway and several proteins controlling EC motility, cytoskeleton remodeling, and energy metabolism pathways. Conclusions: This study provides information on the molecular mechanisms associated with the antimigratory and antiangiogenic effects of lenalidomide in primary MMECs, thus giving new avenues for effective endothelium-targeted therapie

Towards more reliable measurements of sound absorption coefficient in reverberation rooms: An Inter-Laboratory Test

The internationally recognized procedure ISO 354:2003 for measuring sound absorption coefficients under diffuse field conditions is now under revision. The main reason for this revision is the limited reproducibility of absorption coefficients measured in different laboratories that may have significant implications spanning from room acoustic design to material selection. A network of Italian laboratories have come together to carry out an Inter-Laboratory Test (ILT) to assess and compare the measurement uncertainties resulting from the application of the current version of ISO 354:2003 and of the new ISO/CD 354:2019. After detailing the methodological aspects, the paper presents the results of the measurements, discussing the compliance of the laboratories to the standard requirements and new qualification tests, and, more importantly, providing a quantitative estimation of their effects on measurement uncertainty and accuracy

Design Principles of the Italian Round Robin Test on Reverberation Rooms

This paper describes the design principles underlying the Round Robin Test (RRT) carried out among the laboratories of the Sound Absorption working group of the Italian Standardization Body (UNI). In recent years, the determination of the measurement uncertainties in the fields of building and room acoustics has attracted increasing attention. In particular, sound absorption in a diffuse sound field might be difficult to determine, especially for very highly absorptive materials. Results coming from different laboratories cannot always be compared, due to differences in the actual sound field found in nominally equivalent facilities. During this RRT, carefully selected samples have been measured in the reverberation rooms of the different laboratories participating in the RRT according to standard ISO 354 in force as well as the newly proposed draft. The procedure will be presented in the paper