105 research outputs found

    2D Electrical Resistivity Tomography surveys optimisation of solutes transports in porous media

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    International audienceThe purpose of this study is to quantify experimentally the evolution of dissolved species in porous media from 2D resistivity models. Transport experiments are carried out at the laboratory scale by performing flow in a model porous medium obtained by filling a transparent container with mono disperse glass beads. A tracer made by mixing a dissolved of blue dye and a known NaCl concentration is injected with a constant flow rate through the porous medium already saturated by a transparent fluid. ERT measurements are acquired during the fluid flow. The measurement conditions and the inversion parameters are estimated so that the relation between spatial and temporal resolutions is optimised. A video follow-up is also carried out during the upward tracer propagation. The comparison of the temporal evolution of the NaCl concentration distribution estimated from ERT models with Video analysis shows remarkable agreement

    Evaluation of the effects of short-term amendment with olive mill pomace on some soil properties

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    The extraction of olive oil produces an enormous quantity of waste, such as olive mill wastewater (OMWW) and olive mill pomace (OMP), The majority of the agricultural wastes, including olive oil mill waste, are used as soil amendments due to their high nutritional value. The purpose of this study was to investigate the effects of the amendment with olive mill pomace from a 3-phase cold-pressed system on the characteristics of the soil pH, electrical conductivity (EC), and organic matter content (OM). The experiment was carried out using increasing rates of olive mill pomace (12.5%, 25%, 50%, 75%, and 100% w/w) plus the control untreated soil in microcosms under laboratory conditions. The results showed that the treatment of soil with olive mill pomace has a significant effect on soil properties (pH, EC, OM, OC, and CaCO3) soil pH was decreased under OMP treatment, especially with high doses of PR4 and PR5, and the electrical conductivity of the soil (EC) was increased, as well as soil carbonate content. Moreover, the soil organic matter content and soil organic carbon content were highly increased under the treatment with OMP. As a result, we can consider the olive mill pomace as a soil fertilizer. Pretreatment of olive mill pomace to reduce acidic pH and salt content before use as a soil amendment is also recommended. © 2022 by the authors

    Comparative Study to Optimize Surface Roughness of the Titanium Alloy Ti-6Al-4V by Applying Taguchi, RSM and TLBO Methods

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    Titanium alloys are used in aeronautics and the shipbuilding industry for their good intrinsic properties, namely low density (40% less than steel), very good mechanical properties and resistance to corrosion. The purpose of this study is to optimize the cutting conditions during the turning of Ti-6Al-4V titanium alloy with Minimum of Quantity of Lubrication (MQL) conditions leading to minimize the surface roughness (Ra). The tests were carried out according to a Taguchi L18 design plan by varying four input factors namely: the cutting speed, the feed rate, the depth of cut and the cutting tool material (coated carbide with (PVD) (GC1125) and uncoated carbide (H13A)). Analysis of variance (ANOVA) was used to found the contribution of each factor and to determine which parameters had a significant influence on the surface roughness. The treatment of the results made it possible to propose a mathematical model, which allows predicting Ra. In addition, Taguchi Signal/Noise (S/N) analysis was used in order to optimize the cutting conditions permitting to minimize Ra. The Desirability Function (DF) was also determined. In addition, the obtained results were compared to the one determined using Response Surface Methodology (RSM) and Teaching and Learning Based Optimization (TLBO). It is important to note that the TLBO method gave a very satisfactory result

    2D Electrical Resistivity Tomography survey optimisation of solute transport in porous media

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    The purpose of this study is to quantify experimentally the evolution of dissolved species in porous media from 2D resistivity models. Transport experiments are done at the lab level by performing flow in a model porous medium obtained by filling a transparent container with mono disperse glass beads. A tracer made by mixing a dissolved blue dye and a known NaCl concentration is injected with a constant flow rate through the porous medium already saturated by a transparent fluid. ERT measurem..

    Activation of Rac1 and the p38 Mitogen-activated Protein Kinase Pathway in Response to All-trans-retinoic Acid

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    Several signaling pathways are activated by all-trans-retinoic acid (RA) to mediate induction of differentiation and apoptosis of malignant cells. In the present study we provide evidence that the p38 MAP kinase pathway is activated in a RA-dependent manner in the NB-4, acute pro-myelocytic leukemia, and the MCF-7, breast carcinoma, cell lines. RA treatment of cells induces a time- and dose-dependent phosphorylation of p38, and such phosphorylation results in activation of its catalytic domain. p38 activation is not inducible by RA in a variant NB-4 cell line, NB-4.007/6, which is resistant to the effects of RA, suggesting a role for this pathway in the induction of RA responses. Our data also demonstrate that the small G-protein Rac1 is activated by RA and functions as an upstream regulator of p38 activation, whereas the MAPKAPK-2 serine kinase is a downstream effector for the RA-activated p38. To obtain information on the functional role of the Rac1/p38/MAPKAPK-2 pathway in RA signaling, the effects of pharmacological inhibition of p38 on RA-induced gene transcription and cell differentiation were determined. Our results indicate that treatment of cells with the SB203580 inhibitor does not inhibit RA-dependent gene transcription via retinoic acid response elements or induction of Stat1 protein expression. However, treatment with SB203580 or SB202190 strongly enhances RA-dependent induction of cell differentiation and RA-regulated growth inhibitory responses. Altogether, our findings demonstrate that the Rac1/p38 MAP kinase pathway is activated in a RA-dependent manner and exhibits negative regulatory effects on the induction of differentiation

    Molecular analysis of endocrine disruption in hornyhead turbot at wastewater outfalls in southern california using a second generation multi-species microarray.

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    Sentinel fish hornyhead turbot (Pleuronichthysverticalis) captured near wastewater outfalls are used for monitoring exposure to industrial and agricultural chemicals of ~ 20 million people living in coastal Southern California. Although analyses of hormones in blood and organ morphology and histology are useful for assessing contaminant exposure, there is a need for quantitative and sensitive molecular measurements, since contaminants of emerging concern are known to produce subtle effects. We developed a second generation multi-species microarray with expanded content and sensitivity to investigate endocrine disruption in turbot captured near wastewater outfalls in San Diego, Orange County and Los Angeles California. Analysis of expression of genes involved in hormone [e.g., estrogen, androgen, thyroid] responses and xenobiotic metabolism in turbot livers was correlated with a series of phenotypic end points. Molecular analyses of turbot livers uncovered altered expression of vitellogenin and zona pellucida protein, indicating exposure to one or more estrogenic chemicals, as well as, alterations in cytochrome P450 (CYP) 1A, CYP3A and glutathione S-transferase-α indicating induction of the detoxification response. Molecular responses indicative of exposure to endocrine disruptors were observed in field-caught hornyhead turbot captured in Southern California demonstrating the utility of molecular methods for monitoring environmental chemicals in wastewater outfalls. Moreover, this approach can be adapted to monitor other sites for contaminants of emerging concern in other fish species for which there are few available gene sequences

    Efficiency of Hydrogen Peroxide and Fenton Reagent for Polycyclic Aromatic Hydrocarbon Degradation in Contaminated Soil: Insights from Experimental and Predictive Modeling

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    \ua9 2024 by the authors.This study investigates the degradation kinetics of polycyclic aromatic hydrocarbons (PAHs) in contaminated soil using hydrogen peroxide (H2O2) and the Fenton process (H2O2/Fe2+). The effect of oxidant concentration and the Fenton molar ratio on PAH decomposition efficiency is examined. Results reveal that increasing H2O2 concentration above 25 mmol/samples leads to a slight increase in the rate constants for both first- and second-order reactions. The Fenton process demonstrates higher efficiency in PAH degradation compared to H2O2 alone, achieving decomposition yields ranging from 84.7% to 99.9%. pH evolution during the oxidation process influences PAH degradation, with alkaline conditions favoring lower elimination rates. Fourier-transform infrared (FTIR) spectroscopy analysis indicates significant elimination of PAHs after treatment, with both oxidants showing comparable efficacy in complete hydrocarbon degradation. The mechanisms of PAH degradation by H2O2 and the Fenton process involve hydroxyl radical formation, with the latter exhibiting greater efficiency due to Fe2+ catalysis. Gaussian process regression (GPR) modeling accurately predicts reduced concentration, with optimized ARD-Exponential kernel function demonstrating superior performance. The Improved Grey Wolf Optimizer algorithm facilitates optimization of reaction conditions, yielding a high degree of agreement between experimental and predicted values. A MATLAB 2022b interface is developed for efficient optimization and prediction of C/C0, a critical parameter in PAH degradation studies. This integrated approach offers insights into optimizing the efficiency of oxidant-based PAH remediation techniques, with potential applications in contaminated soil remediation

    Investigation of photoprotective, anti-inflammatory, antioxidant capacities and lc–esi–ms phenolic profile of astragalus gombiformis pomel

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    Plant-derived compounds have recently been gaining popularity as skincare factors due to their ability to absorb ultraviolet radiations and their anti-inflammatory, and antioxidant properties. In this light, this work aimed to evaluate in vitro the pharmacological activities of the butanolic extract prepared from the aerial parts of Astragalus gombiformis Pomel, an endemic species to southern Algeria. The sun protection factor was used to assess the photoprotective effect (SPF), the protein denaturation method to determine the anti-inflammatory activity, and brine shrimp nauplii and OxHLIA assay, respectively, to assess the cytotoxicity and antioxidant capacity of A. gombiformis. In addition, LC–ESI–MS analysis was employed for the characterization of the phenolic constituents of A. gombiformis. The results showed that A. gombiformis had high capacity for absorbing UV radiations with an SPF of 37.78 ± 0.85 and significant anti-inflammatory activity with a percentage inhibition of 75.38% which is close to that of diclofenac and ketoprofen. In addition, A. gombiformis was found to have effective cytotoxicity against Artemia nauplii with a DC50 value of about 44.7 µg/mL, but a weak hemolytic effect against human erythrocytes. LC–ESI–MS results detected the presence of 17 phenolic compounds with a predominance of cirsiliol, silymarin, quercitrin (quercetin-3-O-rhamnoside), and kaempferol. Taken together, these results suggest that A. gombiformis extract could be used as a skincare agent in cosmetic formulations, providing excellent antioxidant and anti-inflammatory protection, allowing the treatment of skin conditions, as well as a pharmaceutical agent with multidimensional applications.The authors are grateful to the Algerian Ministry of Higher Education and Scientific Research and the National Centre for Biotechnology Research (C.R.B.T) for their respective financial and material supports

    Ultrasound-assisted extraction, LC–MS/MS analysis, anticholinesterase, and antioxidant activities of valuable natural netabolites from Astragalus armatus Willd.: In silico molecular docking and In Vitro enzymatic studies

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    The Astragalus armatus Willd. plant’s phenolic constituent extraction and identification were optimized using the ultrasound-assisted extraction (UAE) method and the LC–MS/MS analysis, respectively. Additionally, cupric reducing antioxidant capacity (CUPRAC), beta carotene, reducing power, DMSO alcalin, silver nanoparticle (SNP)-based method, phenanthroline, and hydroxyl radical tests were utilized to assess the extract’s antioxidant capacity, while the neuroprotective effect was examined in vitro against acetylcholinesterase enzyme. This study accurately estimated the chemical bonding between the identified phenolic molecules derived from LC–MS/MS and the AChE. The extract was found to contain sixteen phenolic substances, and rosmarinic, protocatechuic, and chlorogenic acids, as well as 4-hydroxybenzoic, hyperoside, and hesperidin, were the most abundant substances in the extract. In all antioxidant experiments, the plant extract demonstrated strong antioxidant activity and a significant inhibitory impact against AChE (40.25 ± 1.41 μg/mL). According to molecular docking affinity to the enzyme AChE, the top-five molecules were found to be luteolin, quercetin, naringenin, rosmarinic acid, and kaempferol. Furthermore, these tested polyphenols satisfy the essential requirements for drug-like characteristics and Lipinski’s rule of five. These results highlight the significance of the A. armatus plant in cosmetics, as food additives, and in the pharmaceutical industry due to its rosmarinic and chlorogenic acid content
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