504 research outputs found

    Increased NFκ-B Activity in HCT116 Colorectal Cancer Cell Line Harboring TLR4 Asp299Gly Variant

    Get PDF
    Toll-Like Receptor 4 (TLR4), considered one of the most important TLR, recognizes lipopolysaccharide of gram-negative bacteria. Recognition of ligands by TLRs induces signaling pathways resulting in activation of transcriptional factors such as NF-κB which are involved in the expression of inflammatory cytokines and chemokines. To prevent an inappropriate immune response, a complex network of molecules negatively regulates TLRs and their associated signaling pathways. Two cosegregating single nucleotide polymorphisms of the human TLR4 gene, namely Asp299Gly and Thr399Ile, have been associated with hyporesponsiveness to inhaled LPS. The purpose of this study was to determine the impact of TLR4 gene variant on NF-κB activity in colorectal cancer cell line. HCT116 cells were transfected with wild-type and mutants Flag-CMV1-TLR4 expression vectors. Western blot analysis was performed to evaluate selected molecules involved in TLR4 signaling. NF-κB activity was assessed by dualluciferase reporter assay and cytokine profiles were evaluated by ELISA and Cytometric Bead Array method. Results showed that the activity of pNF-κB was higher in cells harboring TLR4 D299G compared to the other cells. However, the activity of pAKT, pERK1 and pIRAK was higher in wild-type. The results of cytokine measurements showed about four fold higher level of IL-8 in cells with wild-type TLR4. This study suggest that TLR4 Asp299Gly gene variant has an impact on TLR4 signaling and potentially on intestinal homeostasis due to impaired control signals at the epithelial cell level which may lead to chronic intestinal inflammation and interrupted intestinal homeostasis and may eventually lead to colorectal cancer. Copyright© 2012, Iranian Journal of Allergy, Asthma and Immunology. All rights reserved

    Antimicrobial effects of folk medicinal plants from the North of Iran against Mycobacterium tuberculosis

    Get PDF
    Background: Medicinal plants have been used traditionally in Golestan province (north of Iran), against Mycobacterium tuberculosis or the clinical signs of tuberculosis (TB). Objectives: This study aimed to define the inhibitory effects of ethanolic extracts of six of these medicinal plants against Mycobacterium tuberculosis. Materials and Methods: Peganum harmala (seed extract), Punica granatum (peel extract), Digitalis sp. (leaf extract), fruit extract of Citrus lemon, Rosa canina and Berberis vulgaris were extracted in ethanol and their activity against M. tuberculosis isolates were determined by the agar diffusion method. The zone of inhibition (at 200 to 1.6 mg/mL) was measured and the results were compared with isoniazid and rifampin as standard positive controls. Also the concentration of vitamin C of each the extracts was evaluated. Results: The ethanolic extract of Peganum harmala seed and Punica granatum peel exhibited potential activity against all M. tuberculosis isolates with mean inhibitory zone of 18.7 and 18.8 mm, at 200 mg/mL concentration. The mean inhibitory zone around isoniazid and rifampinwere 19.2 and 18.8 mm. Ethanolic extract of Citrus lemon showed moderate inhibitory activity only against sensitive (non MDR; non multi drug resistant) strains of M. tuberculosis, and Digitalis sp. showed inhibitory effects on five isolates. Ascorbic acid content was 43.3 mg/dL in Punica granatum and Digitalis sp. and only 9.1 mg/dL in ethanolic extract of Peganum harmala. Conclusions: The highest content of vitamin C was observed in the extract of Punica granatum, which was observed to be highly active against Mycobacterium tuberculosis, while the P. harmala must have contained other phytochemical constituents that contributed to the anti-tuberculosis effects of this plant. Our findings showed that ethanolic extracts of P. granatum and P. harmala had anti-TB effects comparable to isoniazid and rifampin and can be good candidates for novel and safe natural products against tuberculosis. © 2015, Pediatric Infections Research Center

    Applications of Genetic Algorithm and Its Variants in Rail Vehicle Systems: A Bibliometric Analysis and Comprehensive Review

    Get PDF
    Railway systems are time-varying and complex systems with nonlinear behaviors that require effective optimization techniques to achieve optimal performance. Evolutionary algorithms methods have emerged as a popular optimization technique in recent years due to their ability to handle complex, multi-objective issues of such systems. In this context, genetic algorithm (GA) as one of the powerful optimization techniques has been extensively used in the railway sector, and applied to various problems such as scheduling, routing, forecasting, design, maintenance, and allocation. This paper presents a review of the applications of GAs and their variants in the railway domain together with bibliometric analysis. The paper covers highly cited and recent studies that have employed GAs in the railway sector and discuss the challenges and opportunities of using GAs in railway optimization problems. Meanwhile, the most popular hybrid GAs as the combination of GA and other evolutionary algorithms methods such as particle swarm optimization (PSO), ant colony optimization (ACO), neural network (NN), fuzzy-logic control, etc with their dedicated application in the railway domain are discussed too. More than 250 publications are listed and classified to provide a comprehensive analysis and road map for experts and researchers in the field helping them to identify research gaps and opportunities

    Energy Management Systems for Smart Electric Railway Networks: A Methodological Review

    Get PDF
    Energy shortage is one of the major concerns in today’s world. As a consumer of electrical energy, the electric railway system (ERS), due to trains, stations, and commercial users, intakes an enormous amount of electricity. Increasing greenhouse gases (GHG) and CO2 emissions, in addition, have drawn the regard of world leaders as among the most dangerous threats at present; based on research in this field, the transportation sector contributes significantly to this pollution. Railway Energy Management Systems (REMS) are a modern green solution that not only tackle these problems but also, by implementing REMS, electricity can be sold to the grid market. Researchers have been trying to reduce the daily operational costs of smart railway stations, mitigating power quality issues, considering the traction uncertainties and stochastic behavior of Renewable Energy Resources (RERs) and Energy Storage Systems (ESSs), which has a significant impact on total operational cost. In this context, the first main objective of this article is to take a comprehensive review of the literature on REMS and examine closely all the works that have been carried out in this area, and also the REMS architecture and configurations are clarified as well. The secondary objective of this article is to analyze both traditional and modern methods utilized in REMS and conduct a thorough comparison of them. In order to provide a comprehensive analysis in this field, over 120 publications have been compiled, listed, and categorized. The study highlights the potential of leveraging RERs for cost reduction and sustainability. Evaluating factors including speed, simplicity, efficiency, accuracy, and ability to handle stochastic behavior and constraints, the strengths and limitations of each optimization method are elucidated

    Effect of substrate grain size on structural and corrosion properties of electrodeposited nickel layer protected with self-assembled film of stearic acid

    Get PDF
    In the present study, the impact of copper substrate grain size on the structure of the succeeding electrodeposited nickel film and its consequent corrosion resistance in 3.5% NaCl medium were evaluated before and after functionalization with stearic acid. Nickel layers were electrodeposited on two different copper sheets with average grain size of 12 and 25 \u3bcm, followed by deposition of stearic acid film through self-assembly. X-ray diffraction analysis of the electrodeposited nickel films revealed that the deposition of nickel film on the Cu substrate with small (12 \u3bcm) and large (25 \u3bcm) grains is predominantly governed by growth in the (220) and (111) planes, respectively. Both electrodeposited films initially exhibited a hydrophilic nature, with water-contact angles of 56\ub0 and <10\ub0, respectively. After functionalization with stearic acid, superhydrophobic films with contact angles of ~150\ub0 were obtained on both samples. In a 3.5% NaCl medium, the corrosion resistance of the nickel layer electrodeposited on the copper substrate with 25 \u3bcm grains was three times greater than that deposited on the copper substrate with 12 \u3bcm grains. After functionalization, the corrosion resistance of both films was greatly improved in both short and long immersion times in 3.5% NaCl medium

    Recycled cobalt from spent Li-ion batteries as a superhydrophobic coating for corrosion protection of plain carbon steel

    Get PDF
    A new recycling and film formation scheme is developed for spent Li-ion batteries, which involves the combination of ascorbic-assisted sulfuric leaching and electrodeposition to fabricate a corrosion resistance superhydrophobic coating. The idea behind the simultaneous use of sulfuric and ascorbic is to benefit from the double effect of ascorbic acid, as a leaching reducing agent and as morphological modifier during electrodeposition. Quantum chemical calculations based on the density functional theory are performed to explain the cobalt-ascorbate complexation during the electrocristalization. The optimum parameters for the leaching step are directly utilized in the preparation of an electrolyte for the electrodeposition process, to fabricate a superhydrophobic film with a contact angle of > 150\ub0 on plain carbon steel. The potentiodynamic polarization measurments in 3.5 wt % NaCl showed that boric-pulsed electrodeposited cobalt film has 20-times lower corrosion current density and higher corrosion potential than those on the non-coated substrate

    Tanzania: Recent Economic Developments

    Get PDF
    https://www.elibrary.imf.org/doc/IMF002/06676-9781451838282/06676-9781451838282/Other_formats/Source_PDF/06676-9781463912642.pd
    • …
    corecore