Geophysical survey to estimate the 3D sliding surface and the 4D evolution of the water pressure on part of a deep seated landslide

International audienceGeophysical surveys were conducted on the very unstable front part of the La Clapière landslide in the French Alps (Alpes Maritimes). The electrical resistivity survey was carried out to obtain, for the first time on this deep-seated landslide, 3D information on the slipping surface and the vertical drained faults. Moreover, we planned to follow within time (6 months) the evolution of the saturated zones (presence of gravitational water) and their percolation into the shearing zones. Our 4D results showed the importance of the complex water channelization within the slope and relation to geological discontinuities

Design and Simulation of a Multi-Sensor System Growing a Plurality of Heater Chips on the Same Dielectric Membrane

In micro-sensors, the Micro Hotplate (MHP) is a crucial component, in particularly gas sensors. To control the temperature of the sensing layer, micro-heater is used in metal oxide gas (MOX) sensors as a hotplate. The temperature should be in the requisite temperature range over the heater area. This allows detection of the resistive changes as a function of varying concentration of different gases. Thus, their design is a very important aspect. In this paper, we presented the design and simulation results of a platinum combinative meander-spiral micro heater for a WO3 gas sensor. The objective of this paper is also to model a multi-sensor while growing a plurality of heater chips on the same membrane to improve gas sensors selectivity performance. Four different heating voltages were applied in order to attain four maximum temperatures required to detect O3, H2S, CO and NO2, by a WO3 multi- sensor

Design and Simulation of a Multi-Sensor System Growing a Plurality of Heater Chips on the Same Dielectric Membrane

In micro-sensors, the Micro Hotplate (MHP) is a crucial component, in particularly gas sensors. To control the temperature of the sensing layer, micro-heater is used in metal oxide gas (MOX) sensors as a hotplate. The temperature should be in the requisite temperature range over the heater area. This allows detection of the resistive changes as a function of varying concentration of different gases. Thus, their design is a very important aspect. In this paper, we presented the design and simulation results of a platinum combinative meander-spiral micro heater for a WO3 gas sensor. The objective of this paper is also to model a multi-sensor while growing a plurality of heater chips on the same membrane to improve gas sensors selectivity performance. Four different heating voltages were applied in order to attain four maximum temperatures required to detect O3, H2S, CO and NO2, by a WO3 multi- sensor

Structure and Thermal Transitions in a Biomedically Relevant Liquid Crystalline Poly(ester amide)

There is still a need to develop bioresorbable polymers with high strength and high modulus for load-bearing biomedical applications. Here we investigate the liquid crystalline structural features of poly(desaminotyrosyl-tyrosine dodecyl dodecanedioate), poly(DTD DD), a new bioresorbable poly(ester amide) that is currently studied in vivo as a slow-degrading implantable biomaterial for load bearing applications. Thermally induced structural changes in poly(DTD DD) were studied using simultaneously differential scanning calorimetry (DSC) and X-ray scattering. The hexatic SmB organization of the polymer chains that exists at room temperature becomes progressively disordered upon heating, changing into a SmF phase and then into a smectic C phase at 60 °C before turning into a free-flowing melt at 130 °C. X-ray scattering data and thermal analysis indicate the presence of a 2D ordered structure in the polymer melt. A structural model with an interesting 3-fold symmetry in the packing of the side chains around the rigid aromatic main chain, and the packing of these chains into fibrils is proposed. The liquid crystalline behavior of poly(DTD DD) makes it possible to melt process it at low temperatures without thermal degradation. This is a noteworthy advantage for the use of poly(DTD DD) as a high strength, readily processable, yet biodegradable polymer

Triggering a Phase Transition by a Spatially Localized Laser Pulse: Role of Strain

Metals in Catalysis, Biomimetics & Inorganic Material

Putative IKDCs are functionally and developmentally similar to natural killer cells, but not to dendritic cells

Interferon-producing killer dendritic cells (IKDCs) have been described as possessing the lytic potential of NK cells and the antigen-presenting capacity of dendritic cells (DCs). In this study, we examine the lytic function and antigen-presenting capacity of mouse spleen IKDCs, including those found in DC preparations. IKDCs efficiently killed NK cell targets, without requiring additional activation stimuli. However, in our hands, when exposed to protein antigen or to MHC class II peptide, IKDCs induced little or no T cell proliferation relative to conventional DCs or plasmacytoid DCs, either before or after activation with CpG, or in several disease models. Certain developmental features indicated that IKDCs resembled NK cells more than DCs. IKDCs, like NK cells, did not express the transcription factor PU.1 and were absent from recombinase activating gene-2–null, common γ-chain–null (Rag2−/−Il2rg−/−) mice. When cultured with IL-15 and -18, IKDCs proliferated extensively, like NK cells. Under these conditions, a proportion of expanded IKDCs and NK cells expressed high levels of surface MHC class II. However, even such MHC class II+ IKDCs and NK cells induced poor T cell proliferative responses compared with DCs. Thus, IKDCs resemble NK cells functionally, and neither cell type could be induced to be effective antigen-presenting cells

IFNs Modify the Proteome of <i>Legionella</i>-Containing Vacuoles and Restrict Infection Via IRG1-Derived Itaconic Acid

Macrophages can be niches for bacterial pathogens or antibacterial effector cells depending on the pathogen and signals from the immune system. Here we show that type I and II IFNs are master regulators of gene expression during Legionella pneumophila infection, and activators of an alveolar macrophage-intrinsic immune response that restricts bacterial growth during pneumonia. Quantitative mass spectrometry revealed that both IFNs substantially modify Legionella-containing vacuoles, and comparative analyses reveal distinct subsets of transcriptionally and spatially IFN-regulated proteins. Immune-responsive gene (IRG)1 is induced by IFNs in mitochondria that closely associate with Legionella-containing vacuoles, and mediates production of itaconic acid. This metabolite is bactericidal against intravacuolar L. pneumophila as well as extracellular multidrug-resistant Gram-positive and -negative bacteria. Our study explores the overall role IFNs play in inducing substantial remodeling of bacterial vacuoles and in stimulating production of IRG1-derived itaconic acid which targets intravacuolar pathogens. IRG1 or its product itaconic acid might be therapeutically targetable to fight intracellular and drug-resistant bacteria

Cytolytic DNA vaccine encoding lytic perforin augments the maturation of- and antigen presentation by- dendritic cells in a time-dependent manner

The use of cost-effective vaccines capable of inducing robust CD8+ T cell immunity will contribute significantly towards the elimination of persistent viral infections and cancers worldwide. We have previously reported that a cytolytic DNA vaccine encoding an immunogen and a truncated mouse perforin (PRF) protein significantly augments anti-viral T cell (including CD8+ T cell) immunity. Thus, the current study investigated whether this vaccine enhances activation of dendritic cells (DCs) resulting in greater priming of CD8+ T cell immunity. In vitro data showed that transfection of HEK293T cells with the cytolytic DNA resulted in the release of lactate dehydrogenase, indicative of necrotic/lytic cell death. In vitro exposure of this lytic cell debris to purified DCs from naïve C57BL/6 mice resulted in maturation of DCs as determined by up-regulation of CD80/CD86. Using activation/proliferation of adoptively transferred OT-I CD8+ T cells to measure antigen presentation by DCs in vivo, it was determined that cytolytic DNA immunisation resulted in a time-dependent increase in the proliferation of OT-I CD8+ T cells compared to canonical DNA immunisation. Overall, the data suggest that the cytolytic DNA vaccine increases the activity of DCs which has important implications for the design of DNA vaccines to improve their translational prospects.Danushka K. Wijesundara, Wenbo Yu, Ben J. C. Quah, Preethi Eldi, John D. Hayball, Kerrilyn R. Diener, Ilia Voskoboinik, Eric J. Gowans, and Branka Grubor-Bau

Spatially Resolved Investigation and Control of the Bistability in Single Crystals of the [Fe(bbpya) (NCS)2] Spin Crossover Complex

The spin transition in single crystals of the [FeII(bbpya) (NCS)2] (bbpya = N,N-bis(2–2?-bipyrid-6-yl)amine) mononuclear complex was investigated by a combination of X-ray diffraction, Raman spectroscopy, as well as optical and atomic force microscopy (AFM) methods. These studies, performed around 440 K, revealed an extremely abrupt spin transition associated with a structural phase transition from a triclinic (low spin) to a monoclinic (mixed low spin/high spin) structure. Spatially resolved observations of this transition evidenced a clear phase separation associated with heterogeneous nucleation and the formation of a moving macroscopic interface whose velocity reached in some cases 300 ?m s–1. Using photothermal control it was possible to stabilize biphasic states of the crystal and then acquire AFM images of the phase boundary. A “sawtooth” like topography was repeatedly observed, which most likely emerges so as to minimize the elastic strain. Remarkably, a fine spatial control of the phase boundary could be also achieved using the AFM probe itself, through probe–sample convective heat exchange