251 research outputs found

    Triggering and modulation of the host-parasite interplay by Echinococcus multilocularis: a review

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    As more facts emerge regarding the ways in which E. multilocularis-derived molecules trigger the host immune response and modulate the host-parasite interplay, it becomes possible to envisage how the parasite can survive and proliferate in its intermediate host, while in other hosts it dies out. Through effects on cells of both the innate and adaptive arms of the immune response, E. multilocularis can orchestrate a range of outcomes that are beneficial not only to the parasite, in terms of facilitating its intrahepatic proliferation and maturation, and thus life cycle over all, but also to its intermediate host, in limiting pathology. The present review deals with the role of metacestode surface molecules as well as excretory/secretory (E/S) metabolic products of the parasite in the modulation of the host responses such as to optimize its own surviva

    Seasonal and regional occurrence of heat-resistant spore-forming bacteria in the course of ultra-high temperature milk production in Tunisia

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    International audienceSpore-forming bacteria, principally Bacillus species, are important contaminants of milk. Because of their high heat resistance, Bacillus species spores are capable of surviving the heat treatment process of milk and lead to spoilage of the final product. To determine the factors influencing the contamination of milk, spore-forming bacteria occurrence throughout the UHT milk production line during winter, spring, and summer was studied. The obtained results confirm that the total viable rate decreases rapidly throughout the production line of UHT milk showing the efficiency of thermal treatments used. However, the persistent high rate of spore-forming bacteria indicates their high heat resistance , especially in spring and summer. In addition, a significant variation of the quality of raw milk according to the location of the collecting centers was revealed. The molecular identification showed a high degree of diversity of heat-resistant Bacillus species, which are isolated from different milk samples. The distribution of Bacillus species in raw milk, stored milk, bactofuged milk, pasteurized milk, and UHT milk were 28, 10, 16, 13, and 33%, respectively. Six Bacillus spp. including Bacillus licheniformis (52.38%), Bacillus pumilus (9.52%), Bacillus sp. (4.76%), Bacillus sporothermodurans (4.76%), Terribacillus aidingensis (4.76%), and Paenibacillus sp. (4.76%) were identified in different milk samples

    A New Algorithm For Solving Isothermal Carbonization Of Wood Particle

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    A new algorithm based on the lattice Boltzmann method (LBM) is proposed as a potential solver for one-dimensional heat and mass transfer for isothermal carbonization of thick wood particles. To check the validity of this algorithm, computational results have been compared with the published data and a good agreement is obtained. Then, the model is used to study the effect of reactor temperature and particle size on the evolution of the local temperature and mass loss inside the wood particle

    Radiation heat transfer effect in solid oxide fuel cell: Application of the Lattice Boltzmann Method

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    the radiation effect within the solid anode, electrolyte, and cathode SOFC layers problem has been investigated in this paper. Energy equation is solved by the Lattice Boltzmann method (LBM). The Rosseland method is used to model the radiative transfer in the electrodes. The Schuster-Schwarzschild method is used to model the radiative transfer in the electrolyte. Without radiatve effect, the found results are in good agreement with those published. The obtained results show that the radiative effect can be neglected

    Characterization of Vortex Development and Thermo-Solutal Transfers on Confined Wall Jets Submitted to Suction or Blowing: Part 2

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    A computational study is conducted to explore the effect of vertical wall suction or blowing on two-dimensional confined wall jet hydrodynamic characteristics. Using an implicit finite volume technique in Cartesian coordinate system, several parameters have been investigated for a wide range of Lewis numbers by fixing the Prandtl number at 7 that corresponds to water. The main purpose is to analyze the control size and location effectiveness on the flow pattern as well as heat and mass transfer rates. Detailed numerical simulations demonstrated that as the local blowing is moved downstream, discrete vortex formation begins at a critical location then shedding phenomenon occurs behind the slot at advanced positions. Since the flow dynamic structure is mainly altered, averages skin friction and thermo-solutal coefficients distributions are largely influenced. Approximately for x_s≤4 (upstream of the natural vortex emission position), Nusselt and Sherwood numbers slightly increase with the control location x_s. However, they gradually decrease as the blowing slot approaches the domain exit. Optimum values were obtained when locating the slot just downstream of the uncontrolled Kelvin-Helmholtz instability onset. Furthermore, computations illustrated that an appropriate suction slot length selection could be a simple and efficient tool to delay or even suppress natural structure emission and development. This choice is essentially related to the recirculation cell size

    Commercial window glass tested as possible high dose dosimeter. Electron and gamma irradiation

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    The use of commercial window glass as possible high dose routine dosimeter has been investigated. Glass samples have been irradiated with doses in the range of 1-50 kGy using 60Co γ source, 4 MeV and 12 MeV electron accelerators. The samples were given a post irradiation thermal treatment (150 oC for 20 min) in order to improve the post irradiation stability of the measured specific optical absorbance, since a rapid fading of the optical absorbance has been observed at room temperature immediately after irradiation. The optical absorbance measurements of the irradiated samples, kept in the dark and at room temperature, were carried on for several weeks. The samples submitted to heat treatment showed a decrease of about 10-15% of the specific optical absorbance that became much less pronounced after 10 days from the irradiation. The response of the window glass plates is energy and dose rate dependent. This study shows the feasibility of using commercial window glass as a routine dosimeter in a certain dose range after proper calibration in the irradiation plant where they are going to be used

    Polarization-Sensitive Photodetectors Based on Directionally Oriented Organic Bulk-Heterojunctions

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    Polarized spectroscopic photodetection enables numerous applications in diverse areas such as sensing, industrial quality control, and visible light communications. Although organic photodetectors (OPDs) can offer a cost-effective alternative to silicon-based technology—particularly when flexibility and large-area arrays are desired—polarized OPDs are only beginning to receive due research interest. Instead of resorting to external polarization optics, this report presents polarized OPDs based on directionally oriented blends of poly(3-hexylthiophene) (P3HT) and benchmark polymer or nonfullerene acceptors fabricated using a versatile solution-based method. Furthermore, a novel postprocessing scheme based on backfilling and plasma etching is advanced to ameliorate high dark-currents that are otherwise inherent to fibrillar active layers. The resulting polarized P3HT:N2200 OPDs exhibit a broad enhancement across all principal figures of merit compared to reference isotropic devices, including peak responsivities of 70 mA W−1^{-1} and up to a threefold increase in 3 dB bandwidth to 0.75 MHz under parallel-polarized illumination. Polarization ratios of up to 3.5 are obtained across a spectral range that is determined by the specific donor–acceptor combinations. Finally, as a proof-of-concept demonstration, polarized OPDs are used for photoelasticity analysis of rubber films under tensile deformation, highlighting their potential for existing and emerging applications in advanced optical sensing

    Polarization-Sensitive Photodetectors Based on Directionally Oriented Organic Bulk-Heterojunctions

    Get PDF
    Polarized spectroscopic photodetection enables numerous applications in diverse areas such as sensing, industrial quality control, and visible light communications. Although organic photodetectors (OPDs) can offer a cost-effective alternative to silicon-based technology—particularly when flexibility and large-area arrays are desired—polarized OPDs are only beginning to receive due research interest. Instead of resorting to external polarization optics, this report presents polarized OPDs based on directionally oriented blends of poly(3-hexylthiophene) (P3HT) and benchmark polymer or nonfullerene acceptors fabricated using a versatile solution-based method. Furthermore, a novel postprocessing scheme based on backfilling and plasma etching is advanced to ameliorate high dark-currents that are otherwise inherent to fibrillar active layers. The resulting polarized P3HT:N2200 OPDs exhibit a broad enhancement across all principal figures of merit compared to reference isotropic devices, including peak responsivities of 70 mA W−1^{-1} and up to a threefold increase in 3 dB bandwidth to 0.75 MHz under parallel-polarized illumination. Polarization ratios of up to 3.5 are obtained across a spectral range that is determined by the specific donor–acceptor combinations. Finally, as a proof-of-concept demonstration, polarized OPDs are used for photoelasticity analysis of rubber films under tensile deformation, highlighting their potential for existing and emerging applications in advanced optical sensing
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