3,131 research outputs found

    Emerging Trends in Polymer Matrix Composites .

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    The performance characteristics of PMC products are determined by the microstructure developed during the processing of composite materials. The structure development in processing is the result of integration of process parameters and inherent material characteristics. The properties of PMCs can thus be manipulated through both changes in the materials composition and process conditions. The present article illustrates the scientific approach followed in engineering of matrix materials and optimization of the processing conditions with specific reference to case studies on toughening of thermosetting resins and structure development in injection molding of thermoplastic composites. A novel approach is demonstrated for toughening of unsaturated polyester resins that involves the use of reactive liquid polymers chemically bonded to the matrix. The use of processing science is demonstrated by the significant effect of the mold temperature on the crystallinity and properties of molded poly (phenylene sulfide), a high performance engineering thermoplastic. An interactive approach is proposed for specific product and applications development

    Endoplasmic Reticulum - Mitochondrial Interactions in House Dust Mite Induced Inflammation

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    Rationale: Airway epithelial cells (AECs) are critical regulators of inflammatory, immune and injury responses to allergens that contribute to asthma pathogenesis. The response of AECs to allergens requires an integrated-complex, extracellular receptors and intracellular organelle interaction to achieve secretion of pro-inflammatory cytokines and chemokines. Endoplasmic reticulum (ER) and mitochondria interactions have previously been shown to induce mitochondrial fission. Mitochondrial fission may be a key parameter allergen induced airway inflammation in asthma. However, ER-mitochondria interactions, mitochondrial fission, and subsequent production and secretion of cytokines and chemokines in response to House Dust Mite (HDM) are not well understood. Objective: Here we will assess the ability of HDM to induce ER-mitochondrial interactions and subsequent mitochondrial fission in human bronchiolar epithelial (HBE) cells. We will also investigate the impact on cytokine production downstream of mitochondrial fission in HBE cells treated with HDM. Methods: ER-mitochondrial interactions were quantified using confocal and epifluorescence microscopy. Cytokine/chemokine profiles were determined by enzyme linked immunosorbant assay (ELISA) using HBE cells treated with HDM. Measurements and Main Results: Using epifluorescence and confocal microscopy we show that ER-mitochondrial contacts are increased in response to HDM treatment, as well as HDM-induced mitochondrial fission increased in HBE cells. Inhibition of DRP1, a protein essential for mitochondrial fission, decreases HDM induced ER-mitochondrial interaction. In addition, HDM-induced pro-inflammatory cytokines were decreased in HBE cells where mitochondrial fission is inhibited. Conclusion: HDM induces ER-Mitochondrial interactions that promote mitochondrial fission and subsequent production of pro-inflammatory cytokines

    Zika virus infection reprograms global transcription of host cells to allow sustained infection.

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    Zika virus (ZIKV) is an emerging virus causally linked to neurological disorders, including congenital microcephaly and Guillain-Barré syndrome. There are currently no targeted therapies for ZIKV infection. To identify novel antiviral targets and to elucidate the mechanisms by which ZIKV exploits the host cell machinery to support sustained replication, we analyzed the transcriptomic landscape of human microglia, fibroblast, embryonic kidney and monocyte-derived macrophage cell lines before and after ZIKV infection. The four cell types differed in their susceptibility to ZIKV infection, consistent with differences in their expression of viral response genes before infection. Clustering and network analyses of genes differentially expressed after ZIKV infection revealed changes related to the adaptive immune system, angiogenesis and host metabolic processes that are conducive to sustained viral production. Genes related to the adaptive immune response were downregulated in microglia cells, suggesting that ZIKV effectively evades the immune response after reaching the central nervous system. Like other viruses, ZIKV diverts host cell resources and reprograms the metabolic machinery to support RNA metabolism, ATP production and glycolysis. Consistent with these transcriptomic analyses, nucleoside metabolic inhibitors abrogated ZIKV replication in microglia cells

    Synthesis and Characterization of Naphthalenediimide-Functionalized Flavin Derivatives

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    Two acceptor–acceptor dyads have been synthesized featuring a flavin moiety and a naphthalenediimide (NDI) unit. The NDI unit is linked to the flavin through a short spacer group via either the N(3) or N(10) positions of the flavin. We have investigated the UV-Vis and redox properties of these multi-electron accepting systems which indicate that these materials display the collective properties of their component systems. Fluorescence spectroscopy measurements have revealed that their emission properties are dominated by the flavin unit

    Ayurveda Concept of Immunity and Biological Factors Associated with Immunity

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    The term immunity stands for the power which protects from the diseases, the immune system acts as defense mechanism against many common diseases including infections. The Ayurveda described term Vyadhikshamatva for inherent defense mechanism. There are many drugs especially Rasayana herbs which improves immunity, Bala and Agni. Vyadhikshamatva varies person to person depending upon their Prakriti therefore some person possess good immunity while others deprived the same. The other factors such as diet, environmental factor, genetic predisposition, mental status and life style, etc. also affect Vyadhiksamatwa of individual. Bala and Ojas also associated with inherent immunity, Ojas or Bala helps to prevents manifestations of common infections thus restore normal health status. Ayurveda ways of daily regimen, balanced diet and Yoga can help to improves Vyadhikshamatva. Natural drugs like Guduchi, Ginger, Tulsi, Turmeric and Amalaki, etc. are well known for their immune boosting effects. Present article explores Ayurveda concept of immunity

    Experimental Investigation on Surface Roughness in Electrical Discharge Turning of Ti-6Al-4V Alloy

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    This study presents a novel EDM turning process specially designed and developed to generate precise cylindrical forms on hard and difficult-to-machine materials. For this purpose, a specially designed turning spindle is used. The spindle was mounted on a conventional die-sinking EDM machine to rotate the workpiece. Axially symmetric parts can be manufactured by feeding the shaped tool into the rotating workpiece. In this way an axisymmetric workpiece can be made with small tools at both macro and micro levels. Effects of machining parameters, such as the current, pulse-on time, rotational speed, flushing pressure, and duty factor, on the surface roughness of Ti-6Al-4V alloy in electrical discharge turning were investigated. Taguchi\u27s design of experiment technique was used. Analysis of variance and regression analysis were performed on experimental data. The signal-to-noise ratio analysis was employed to find the optimal condition
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