11 research outputs found

    Helicobacter pylori Impairs Murine Dendritic Cell Responses to Infection

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    International audienceBACKGROUND: Helicobacter pylori, a human pathogen associated with chronic gastritis, peptic ulcer and gastric malignancies, is generally viewed as an extracellular microorganism. Here, we show that H. pylori replicates in murine bone marrow derived-dendritic cells (BMDCs) within autophagosomes. METHODOLOGY/PRINCIPAL FINDINGS: A 10-fold increase of CFU is found between 2 h and 6 h p.i. in H. pylori-infected BMDCs. Autophagy is induced around the bacterium and participates at late time points of infection for the clearance of intracellular H. pylori. As a consequence of infection, LC3, LAMP1 and MHC class II molecules are retained within the H. pylori-containing vacuoles and export of MHC class II molecules to cell surface is blocked. However, formalin-fixed H. pylori still maintain this inhibitory activity in BMDC derived from wild type mice, but not in from either TLR4 or TLR2-deficient mice, suggesting the involvement of H. pylori-LPS in this process. TNF-alpha, IL-6 and IL-10 expression was also modulated upon infection showing a TLR2-specific dependent IL-10 secretion. No IL-12 was detected favoring the hypothesis of a down modulation of DC functions during H. pylori infection. Furthermore, antigen-specific T cells proliferation was also impaired upon infection. CONCLUSIONS/SIGNIFICANCE: H. pylori can infect and replicate in BMDCs and thereby affects DC-mediated immune responses. The implication of this new finding is discussed for the biological life cycle of H. pylori in the host

    Quality attributes of Bearss Seedless lime (Citrus latifolia Tan) juice during storage.

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    The composition of three types of date juices, that differs by their couple of extraction and obtained from the rest of the sorting of cultivars Deglet Nour, were studied. The fruits were grown in Djerid region (Tozeur, Tunisia). Juices were characterised by yield, pH, soluble solids, organic acid, minerals content, individual carbohydrates, vitamin C, yeasts and moulds, coliforms and flora total aerobe contents. For the physicochemical parameters, only the J3 presents the best yields with content in citric acid of 2.13 g L-1, in phosphor of 0.083% (dry mater), in glucose 26.529 g L-1, in fructose 39.59 g L-1 and in sucrose 185.883 g L-1. For the bacteriological parameters, the results show that all prepared juices answer the microbiological requirements of hygiene well

    A Review on Recent Development of Cooling Technologies for Photovoltaic Modules

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    When converting solar energy to electricity, a big proportion of energy is not converted for electricity but for heating PV cells, resulting in increased cell temperature and reduced electrical efficiency. Many cooling technologies have been developed and used for PV modules to lower cell temperature and boost electric energy yield. However, little crucial review work was proposed to comment cooling technologies for PV modules. Therefore, this paper has provided a thorough review of the up-to-date development of existing cooling technologies for PV modules, and given appropriate comments, comparisons and discussions. According to the ways or principles of cooling, existing cooling technologies have been classified as fluid medium cooling (air cooling, water cooling and nanofluids cooling), optimizing structural configuration cooling and phase change materials cooling. Potential influential factors and sub-methods were collected from the review work, and their contributions and impact have been discussed to guide future studies. Although most cooling technologies reviewed in this paper are matured, there are still problems need to be solved, such as the choice of cooling fluid and its usability for specific regions, the fouling accumulation and cleaning of enhanced heat exchangers with complex structures, the balance between cooling cost and net efficiency of PV modules, the cooling of circulating water in tropical areas and the freezing of circulating water in cold areas. To be advocated, due to efficient heat transfer and spectral filter characters, nanofluids can promote the effective matching of solar energy at both spectral and spatial scales to achieve orderly energy utilization

    An overview of the System of Rice Intensification for Paddy Fields of Malaysia

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