142 research outputs found

    Scientific Research: Publication and Visibility of Institutes and Countries in Relation to Development

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    The aim of this paper is to provide an overview of the role of scientific research in ranking universities at the international or African scale. The number and quality of of journals published by institutions as well as their presence in databases such as Web of science, Scopus, Google Scholar, etc., affect their visibility and reputation. Each researcher has an identifier (ID) and is evaluated based on  the publication number, total citations, Impact factor, etc. Findings on several databases show that China is the leader since the year 2000. In 2022, China published more than one million papers exceeding the US (702840 papers). Among African countries, Morocco ranks fourth behind Egypt, South Africa and Nigeria. The indexed journals on SCImago highlighted the urgent  for policy makers to develop IMIST (Institut Marocain de l’Information Scientifique et Technique) to improve the scientific information and communication system in Morocc

    Effects of magnesium treatment in a model of internal capsule lesion in spontaneously hypertensive rats

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    <p><b>Background and Purpose:</b> The study aim was to assess the effects of magnesium sulfate (MgSO4) administration on white matter damage in vivo in spontaneously hypertensive rats.</p> <p><b>Methods:</b> The left internal capsule was lesioned by a local injection of endothelin-1 (ET-1; 200 pmol) in adult spontaneously hypertensive rats. MgSO4 was administered (300 mg/kg SC) 30 minutes before injection of ET-1, plus 200 mg/kg every hour thereafter for 4 hours. Infarct size was measured by T2-weighted magnetic resonance imaging (day 2) and histology (day 11), and functional recovery was assessed on days 3 and 10 by the cylinder and walking-ladder tests.</p> <p><b>Results:</b> ET-1 application induced a small, localized lesion within the internal capsule. Despite reducing blood pressure, MgSO4 did not significantly influence infarct volume (by magnetic resonance imaging: median, 2.1 mm3; interquartile range, 1.3 to 3.8, vs 1.6 mm3 and 1.2 to 2.1, for the vehicle-treated group; by histology: 0.3 mm3 and 0.2 to 0.9 vs 0.3 mm3 and 0.2 to 0.5, respectively). Significant forelimb and hindlimb motor deficits were evident in the vehicle-treated group as late as day 10. These impairments were significantly ameliorated by MgSO4 in both cylinder (left forelimb use, P<0.01 and both-forelimb use, P<0.03 vs vehicle) and walking-ladder (right hindlimb score, P<0.02 vs vehicle) tests.</p> <p><b>Conclusions:</b> ET-1–induced internal capsule ischemia in spontaneously hypertensive rats represents a good model of lacunar infarct with small lesion size, minimal adverse effects, and a measurable motor deficit. Despite inducing mild hypotension, MgSO4 did not significantly influence infarct size but reduced motor deficits, supporting its potential utility for the treatment of lacunar infarct.</p&gt

    Effect of Calcium/phosphorus Ratio on the Chemical and Structural Properties of Oxygenated Apatite Synthesized by Neutralization

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    Zinc oxide-based cements are commonly used to fill dental canals, but they have drawbacks such as poor bonding and bacterial infection. In this work, we propose a novel phosphocalcic apatitic cement/oxygenated apatite mixture, which can mimic the natural filling of dental canals. Oxygenated apatite is a type of apatite that contains molecular oxygen in their tunnels. We aim to evaluate the effect of the Calcium/Phosphorus (Ca/P) atomic ratio on the chemical and structural properties of the synthesized oxygenated apatite, as well as on the quantity of oxygen retained in their tunnels. We use the neutralization method to precipitate apatite from lime milk and orthophosphoric acid, in the presence of hydrogen peroxide. We characterize the materials the materials by X-ray diffraction, infrared absorption spectroscopy, thermal analysis, adsorption-desorption of nitrogen, and elemental analysis. We obtain simple oxygenated apatitic phases with a Ca/P ratio ranging from 1.53 to 1.76, an oxygen insertion rate of 3.5x10-4 moles, and a chemical formula of Ca9,9(PO4)6(OH)2(O2)0,69(CO2)0,01. We find that the deviation from stoichiometry and calcination at 900°C lead to the formation of a biphasic mixture of PAH/β-TCP. The synthesized apatites have low crystallinity and high specific surface area, which decreases from 156.3 to 141.6 m2/g as the Ca/P ratio increases

    ROSEMARY ESSENTIAL OILS: EXTRACTION, GC/MS ANALYSIS, ANTIOXIDANT ACTIVITY WITH DFT AND IN SILICO INSIGHTS OF PROSPECTIVE NANO-ANTIOXIDANTS

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    The objective of this work is to identify the bioactive molecules in the essential oil of the dried leaves of Rosemary from two cities in the Eastern region of Morocco: Taourirt and Jerrada. These essential oils have already been extracted by the steam distillation method in the cooperative. the chemical composition have been determined by gas chromatography coupled with mass spectrometry (GC/MS), in which cineole 41.77%, alpha-Pinene 10.75% and Camphor 9.32% represent the majority compounds for essential oil of Rosemary from Taourirt and cineole 51.68%, alpha-Pinene 11.91 % and Camphor 10.29 % predominate in that of Jerada rosemary. Antioxidant activity in vitro was assessed in three different ways: the DPPH test, the β-carotene bleaching technique, and the reduction power measurement. The DFT analysis of the different compounds and the Docking study were also investigated in objective to study the molecular reactivity of the majority compounds, also study their affinity to various cyclodextrin as prospective encapsulation systems

    Comparative study of inhibitory efficacy of methionine and its derivatives in acidic medium by mild steel

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    Corrosion inhibition effect of L-Methionine (MT1), L-Methionine sulfoxide (MT2) and L-Methionine sulfone (MT3) on mild steel corrosion in 1M HCl solution was studied by using weight loss, electrochemical polarization and electrochemical impedance spectroscopy (EIS) techniques. The experimental results showed that the inhibitory efficiency of the three aminoacids improves with the increase of concentration to reach the maximum value of 95.20% for MT1, 94.14% for MT2 and 88.92% for MT3 for a concentration of 10-3M, which translates that the surface covered by the inhibitor increases with the concentration. The effect of temperature on the corrosion rate was investigated and some thermodynamic parameters were calculated. Polarization studies show that three studied inhibitors suggested that three inhibitors control the anodic as well as cathodic reactions and act as mixed type in nature. The results show that MT1, MT2 and MT3 are good inhibitors, and the adsorption of each inhibitor on mild steel surface obeys Flory-Huggins and Langmuir, with a better fit of the Langmuir isotherm through mixed adsorption (physisorption as well as chemisorption) process. In addition, the quantum approach based on density functional theory (DFT), monte Carlo (MC) and molecular dynamics (MD) simulations was confirmed the reactivity of the studied compound towards the corrosion process

    Nanocellulose fibers: A Review of Preparation Methods, Characterization Techniques, and Reinforcement Applications

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    Cellulose, which occurs naturally in abundance, has the benefit of being the most widely used biomass material on a global scale. It is generated from natural fibers and can be processed to produce various types of nanocellulose fibers, each with its hierarchical configuration. This review summarizes current advances in the production of nanocellulose particles, focusing on the analytical techniques most widely used for their preparation, extraction, and characterization. These techniques include FT-IR, TGA, FESEM, and XRD. The review also demonstrates that research into nanocellulose fibers has progressed exponentially over the last decade (over 400 references). Many manufacturing techniques have been developed to use nanofibers in multiple applications as advanced sustainable materials. The presented data will reinforce the applications of nanocellulose fibers for various purposes
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