DLI-CVD of TiO2–Cu antibacterial thin films: Growth and characterization

TiO2–Cu nanocomposite films were grown by pulsed direct liquid injection chemical vapor deposition (DLICVD) on stainless steel, silicon and glass substrates with the goal to produce bactericidal surfaces. Copper bis (2,2,6,6-tetramethyl-3,5-heptadionate), Cu(TMHD)2, and titanium tetra-iso-propoxide, TTIP, were used as metalorganic precursors. Liquid solutions of these compounds in xylene were injected in a flash vaporization chamber connected to a cold wall MOCVD reactor. The deposition temperature was typically 683 K and the total pressure was 800 Pa. The copper content of the layers was controlled by the mole fraction of Cu (TMHD)2 which was adjusted by the injection parameters (injection frequency and concentration of the starting solution). The chemical, structural and physical characteristics of the films were investigated by XRD, XPS, FEG-SEM and TEM. Copper is incorporated as metal particles with a relatively large size distribution ranging from 20 to 400 nm (with a large majority in 20–100 nm) depending on the copper content of the films. The influence of the growth conditions on the structural features and the antibacterial properties of the thin films are reported and discussed

Comparative study of antibacterial efficiency of M-TiO2 (M = Ag, Cu) thin films grown by CVD

M-TiO2 (M = Ag, Cu) nanocomposite layers were grown by pulsed direct liquid injection chemical vapor deposition (DLICVD) on various substrates to produce bactericidal surfaces with long term activity. Monodisperse Ag nanoparticles (NPs) with an average size of 5-10 nm are embedded in an anatase matrix. A bactericidal behavior determined by the JIS Z 2801 standard test was found for Ag-TiO2 films for Ag ≤ 1 at. % and above. Higher Ag content is not necessary since efficiency is already at its maximum (relative activity 100%). By contrast, using Cu as antibacterial agent, a larger size distribution of metal particles was found (20 to 400 nm). Cu-TiO2 films exhibit a bactericidal behavior if their thickness is higher than 100 nm and Cu content ≥ 3.5 at. %. These coatings are still antibacterial after 5 months of aging and their efficiency has decreased by only 35%

The High-Resolution Imaging (HRI) Portable Array: A Seismic (and Internet) Network Dedicated to Kilometric-scale Seismic Imaging

International audienceWe have developed a network of portable seismic stations dedicated to the high resolution imaging of geological, potentially hazardous, targets. These targets - volcanoes, fault zones, landslide areas - are characterized by strong medium heterogeneities, rugged topography, rough field conditions, and require dedicated equipment in order to maximize the number of recording points. This new network is designed to a) operate experiments with a limited size crew, b) run on low power for possible use in remote areas and difficult conditions, c) record both active and passive seismic sources. The actual network consists of 30 clusters of 9 channels digital acquisition system (DAS), equipped with 6 vertical sensors plus 1 three-component sensor. Each DAS uses Ethernet and 802.11 (WiFi) connections that permit to a single operator to remotely control the entire network. We present the main characteristics of this new portable array, describe the calibration method developed for our sensors and show examples of configuration and recordings for two recent experiments

Semi-empirical dissipation source functions for ocean waves: Part I, definition, calibration and validation

New parameterizations for the spectra dissipation of wind-generated waves are proposed. The rates of dissipation have no predetermined spectral shapes and are functions of the wave spectrum and wind speed and direction, in a way consistent with observation of wave breaking and swell dissipation properties. Namely, the swell dissipation is nonlinear and proportional to the swell steepness, and dissipation due to wave breaking is non-zero only when a non-dimensional spectrum exceeds the threshold at which waves are observed to start breaking. An additional source of short wave dissipation due to long wave breaking is introduced to represent the dissipation of short waves due to longer breaking waves. Several degrees of freedom are introduced in the wave breaking and the wind-wave generation term of Janssen (J. Phys. Oceanogr. 1991). These parameterizations are combined and calibrated with the Discrete Interaction Approximation of Hasselmann et al. (J. Phys. Oceangr. 1985) for the nonlinear interactions. Parameters are adjusted to reproduce observed shapes of directional wave spectra, and the variability of spectral moments with wind speed and wave height. The wave energy balance is verified in a wide range of conditions and scales, from gentle swells to major hurricanes, from the global ocean to coastal settings. Wave height, peak and mean periods, and spectral data are validated using in situ and remote sensing data. Some systematic defects are still present, but the parameterizations yield the best overall results to date. Perspectives for further improvement are also given.Comment: revised version for Journal of Physical Oceanograph

A genome-wide association study by ImmunoChip reveals potential modifiers in myelodysplastic syndromes

Because different findings suggest that an immune dysregulation plays a role in the pathogenesis of myelodysplastic syndrome (MDS), we analyzed a large cohort of patients from a homogeneous Sardinian population using ImmunoChip, a genotyping array exploring 147,954 single-nucleotide polymorphisms (SNPs) localized in genomic regions displaying some degree of association with immune-mediated diseases or pathways. The population studied included 133 cases and 3,894 controls, and a total of 153,978 autosomal markers and 971 non-autosomal markers were genotyped. After association analysis, only one variant passed the genome-wide significance threshold: rs71325459 (p = 1.16 × 10−12), which is situated on chromosome 20. The variant is in high linkage disequilibrium with rs35640778, an untested missense variant situated in the RTEL1 gene, an interesting candidate that encodes for an ATP-dependent DNA helicase implicated in telomere-length regulation, DNA repair, and maintenance of genomic stability. The second most associated signal is composed of five variants that fall slightly below the genome-wide significance threshold but point out another interesting gene candidate. These SNPs, with p values between 2.53 × 10−6 and 3.34 × 10−6, are situated in the methylene tetrahydrofolate reductase (MTHFR) gene. The most associated of these variants, rs1537514, presents an increased frequency of the derived C allele in cases, with 11.4% versus 4.4% in controls. MTHFR is the rate-limiting enzyme in the methyl cycle and genetic variations in this gene have been strongly associated with the risk of neoplastic diseases. The current understanding of the MDS biology, which is based on the hypothesis of the sequential development of multiple subclonal molecular lesions, fits very well with the demonstration of a possible role for RTEL1 and MTHFR gene polymorphisms, both of which are related to a variable risk of genomic instability

5G-ALLSTAR: Beyond 5G satellite-terrestrial multi-connectivity

International audienceThis paper presents a summary of the results of the 5G-ALLSTAR project. It describes the enablers that have been developed and validated and will help make 5G and beyond satellite-terrestrial multi-connectivity (MC) a reality in the near future.We proposed and evaluated solutions for critical aspects of the integration of non-terrestrial networks into a 5G and beyond terrestrial network.The OpenAirInterface implementation of the 5G physical layer (PHY) has been upgraded to meet the satellite radio channel constraints. We addressed the issue of co-tier interference between satellite and terrestrial systems. We designed and implemented customized 5G Physical layer, specifically adapted for terrestrial-satellite spectrum sharing. On top of the dedicated beam-forming and hardware design, we validated the full potential of MC by conceiving and testing our proposed resource allocation algorithms based on a custom multipath TCP protocol. The contribution of MC in vehicular use cases has been demonstrated onsite by implementing a terrestrial 5G PHY in conjunction with a satellite/terrestrial traffic controller. Finally, radio resource management solutions were examined. Thanks to these tools, the presence of industry partners in the consortium and to an active participation in standardization, the 5G-ALLSTAR project is an accelerator for the integration of non-terrestrial networks in 5G and beyond