Rapid Aeromonas hydrophila identification by TaqMan PCR assay: comparison with a phenotypic method

International audienceAims: Aeromonas hydrophila is recognized as a human pathogen following wound exposure or ingestion of contaminated water and food. For rapid identification of this bacterium, a TaqMan-based real-time PCR assay has been developed. Methods and Results: Primers and probes that target specific sequences of the 16S rRNA gene and cytolytic enterotoxin gene (aerA) were combined in a duplex assay. Presence and size of PCR products were confirmed with microchannel fluidics electrophoresis analysis. After validation, using type strain CIP7614T DNA, the PCR assay was tested on 12 positive and negative controls. Twenty-one Aeromonas strains were isolated from environmental samples and were identified with biochemical tests as Aer. sobria, Aer. caviae and Aer. hydrophila. Only Aer. hydrophila strains tested positive by PCR assay. Conclusions: The PCR developed here was successfully applied for the identification of Aer. hydrophila from reference, clinical and environmental samples and showed a high discrimination between Aer. hydrophila and other Aeromonas species. Significance and Impact of the Study: This molecular method is convenient, rapid (2 center dot 5 h vs 24 h), specific to identify Aer. hydrophila and usable for diagnosis in medical and veterinary laboratories

Double external cavity laser diode for DWDM applications

International audienceA balanced dual-wavelength external cavity laser diode operating at 1.3 µm is reported with a side-mode suppression ratio of >35 dB. The construction of this laser is based on a double external cavity using a 1:2 coupler and two different Bragg reflectors photo-written within each channel. Thanks to the photo-written external cavity behaviour, a laser with more than eight channels could be considered

Double external cavity laser diode for DWDM applications

International audienceA balanced dual-wavelength external cavity laser diode operating at 1.3 µm is reported with a side-mode suppression ratio of >35 dB. The construction of this laser is based on a double external cavity using a 1:2 coupler and two different Bragg reflectors photo-written within each channel. Thanks to the photo-written external cavity behaviour, a laser with more than eight channels could be considered

OH kinetics in photo-triggered discharges used for VOCs conversion

The kinetic of the hydroxyl radical is studied in N2/O2/H2O mixtures with small amounts of acetone or isopropyl alcohol (0.5%). The radical density is measured in absolute value in the afterglow of a photo-triggered discharge, which generates an homogeneous transient non-equilibrium plasma, using a time resolved absorption measurement method. For dry mixtures, experimental results are compared to predictions of a self-consistent 0D discharge and kinetic model. It is shown that dissociation of the VOCs through quenching collisions of nitrogen metastable states plays an important role in the production of OH. Measurements can not be explained looking only at the oxidation of acetone or IPA by the oxygen atom. This result is reinforced by experimental results about the OH density in wet mixtures, with or without VOCs, compared to dry ones

Collective Microoptics on Fiber Ribbon for Optical Interconnecting Devices

International audienceNew microoptics are proposed to interconnect single-mode fiber (SMF) ribbons. These microoptics allow the increase of the fiber spot size. Low loss, wide misalignment tolerances, long working distance, and low cost could be achieved. The fabrication process and experimental results are presented

Microwave air plasmas in capillaries at low pressure II. Experimental investigation

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Hydrodynamic study of a microwave plasma torch

A hydrodynamic model was developed to simulate the flow and the heat transfer with the gas/plasma system produced by a microwave-driven (500–900 W at 2.45 GHz) axial injection torch, running in atmospheric pressure helium at 3–9 L min−1 input gas flows. The model solves the Navier-Stokes’ equations, including the effect of the plasma upon the momentum and the energy balance, in order to obtain the spatial distributions of the gas velocity and temperature. The model predicts average gas temperatures of 2500–3500 K, in the same range of those obtained by optical measurements. Simulations show that the plasma influences the gas flow path and temperature, promoting an efficient power transfer

Numerical and experimental analysis of microwave micro-plasmas in air

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