709 research outputs found

    Experimental investigation and statistical modelling for assessing the sliding wear of Futilized Filament Fabrication (FFF) fabricated parts

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    A significant historical enabler for the improvement of industrial goods has been the characterization of novel materials. For example, a large variety of polymeric materials are readily accessible to manufacture the appropriate items depending on the production method. Due to its capacity to produce components with complicated geometries without the need for tools or a human interface, fused filament fabrication (FFF) is acquiring a unique edge in the industrial sector. By adjusting process parameters at the right values, the qualities of FFF-built items may be enhanced since they rely heavily on these factors. Increasing the service life of functioning components requires taking wear resistance into account. Because of this, the current work concentrates on a thorough investigation to comprehend the impact of 3 crucial elements, including layer thickness, printing speed, also infill density, infill density, and the sliding wear of test specimens. A mechanism of wear is explained by utilizing microphotographs

    An Innovative Platform Merging Elemental Analysis and Ftir Imaging for Breast Tissue Analysis

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    Histopathology and immunohistology remain the gold standard for breast cancer diagnostic. Yet, these approaches do not usually provide a sufficiently detailed characterization of the pathology. The purpose of this work is to demonstrate for the first time that elemental analysis and Fourier transform infrared spectroscopy microscopic examination of breast tissue sections can be merged into one dataset to provide a single set of markers based on both organic molecules and inorganic trace elements. For illustrating the method, 6 mammary tissue sections were used. Fourier transform infrared (FTIR) spectroscopy images reported a fingerprint of the organic molecules present in the tissue section and laser ablation elemental analysis (LA-ICP-MS) images brought inorganic element profiles. The 6 tissue sections provided 31 106 and 150,000 spectra for FTIR and LA-ICP-MS spectra respectively. The results bring the proof of concept that breast tissue can be analyzed simultaneously by FTIR spectroscopy and laser ablation elemental analysis (LA-ICP-MS) to provide in both case reasonably high resolution images. We show how to bring the images obtained by the two methods to a same spatial resolution and how to use image registration to analyze the data originating from both techniques as one block of data. We finally demonstrates the elemental analysis is orthogonal to all FTIR markers as no significant correlation is found between FTIR and LA-ICP-MS data. Combining FTIR and LA-ICP-MS imaging becomes possible, providing two orthogonal methods which can bring an unprecedented diversity of information on the tissue. This opens a new avenue of tissue section analyses providing unprecedented diagnostic potential. - 2019, The Author(s).This study was made possible by a NPRP Award [7–1267–3–328] from the Qatar National Research Fund (a member of The Qatar Foundation). E.G. is Research Director with the National Fund for Scientific Research (Belgium). The statements made herein are solely the responsibility of the authors.Scopu

    Free Convection of Ag/H2O Nanofluid in Square Cavity with Different Position and Orientation of Egg Shaped Cylinder

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    A numerical simulation was conducted to study the free convection of Ag/H2O nanofluid between a square cavity with cold walls and an egg shaped cylinder with a hot wall. Utilizing the egg equation, dimensionless governing equations were solved using the Galerkin Finite Element Method (GFEM). In this work, several parameters were studied, i.e. Rayleigh number (103 ≤ Ra ≤ 106), volume fraction (0 ≤ φ ≤ 0.05), position (-0.2 ≤ Y ≤ 0.2), and orientation angle (-90° ≤ γ ≤ 90°). The numerical results are presented as streamline contours, isotherm contours, and local and average Nusselt numbers. Moreover, the results were used to analyze the fluids’ structure, temperature distribution, and heat transfer rate. The numerical results confirmed that the stream intensity value increased with an increase of the Rayleigh number as well as the movement of the cylinder towards the bottom wall for all values of the orientation angle. Variation of the vertical position of the cylinder inside the cavity had a noticeable effect on , which increased by 50% at γ = -90°, and by 58% at γ = -45°. However, at Y = -0.2,  increased by 58% at γ = -45° and decreased by 7% at γ = -90°. The highest heat transfer rate was obtained at high Rayleigh number (Ra = 106), volume fraction (φ = 0.05), negative position (Y = -0.2), and the highest positive orientation angle (γ = 90°)

    Coherent states associated to the wavefunctions and the spectrum of the isotonic oscillator

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    Classes of coherent states are presented by replacing the labeling parameter zz of Klauder-Perelomov type coherent states by confluent hypergeometric functions with specific parameters. Temporally stable coherent states for the isotonic oscillator Hamiltonian are presented and these states are identified as a particular case of the so-called Mittag-Leffler coherent states.Comment: 12 page

    EFFICACY AND SAFETY OF ACETAMINOPHEN COMPARED TO TRAMADOL AFTER LAPAROSCOPIC CHOLECYSTECTOMY

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    Abstract Background: Laparoscopic cholecystectomy become widely popular because of its less postoperative pain produced compared to conventional cholecystectomy. The use of opioids postoperatively to reduce pain may be harmful and produce some adverse effects .Tramadol is a centrally acting opioid which is effective for postoperative analgesic pain but produce undesirable adverse effects the patients do not tolerate it so that intravenous acetaminophen could be helpful to optimize postoperative analgesia by reducing the requirement for opioids and their adverse effects.Method: A prospective randomized clinical trial was carried out on 27 adults undergoing elective laparoscopic cholecystectomy were randomly assigned to two groups in this study (13patients) to receive intravenously 1000mg acetaminophen and (14 patients) to receive intramuscularly tramadol 100mg postoperatively; visual analog scale (VAS) was utilized to asses pain severity and efficacy of analgesic agents. Pain scores were assessed at 0,2,4,6,8,10 and 12h after surgery the incidence of adverse effects was also assessed.Results: Over a period of 12hours, visual analog scale (VAS) scores were significantly lower in each group at each time interval compared to zero time; there is a non significant difference in pain score between the different groups; the incidence of adverse effects like nausea and vomiting was significant in tramadol group compared to acetaminophen group.Conclusion: Postoperative intravenous acetaminophen infusion of 1000mg is useful for reducing pain scores after elective laparoscopic cholecystectomy; it is effective and safe analgesic with less adverse effects compared to tramadol.  Key words: laparoscopic cholecystectomy, Acetaminophen, Tramadol, Postoperative analgesia.  Â

    Health promotion, disease prevention and periodic health checks: perceptions and practice among family physicians in eastern Mediterranean region

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    Introduction: The aim of this study was to identify the current practices and perceptions of family physicians regarding health promotion, disease prevention including periodic screening and health checks in Eastern Mediterranean Region. Methods: A multi-country cross-sectional study was conducted in six countries of EMR, from September 2014 to March 2015. Family Physicians who were currently practicing in different countries of EMR were invited to participate in the study through email. A pre-tested structured questionnaire was used for data collection. Data was entered and analyzed on SPSS 19 and logistic regression analysis was performed. Results: A total of 100 physicians data was included in the final analysis. The majority were female physicians (76%): 63% were 25 to 35 years of age. Approximately 53% of Family physicians always recommend periodic screening and health checks to their patients. The common screening question asked to patients in medical history was related to their blood pressure (86%). Almost all (99%) of the Family physicians believe they should conduct periodic health checks. Those who had postgraduate training in Family Medicine (OR: 0.5; 95% CI: 0.39-1.67) and attended CME sessions regularly (OR: 0.11; 95% CI: 0.01-0.93), are more likely to recommend periodic screening and health checks to their patients. Conclusion: Periodic screening and health check is an important strategy to prevent disease and maintain health. It is an underutilized practice and a great need exists for its implementation in family practice

    Investigation of the effect of PD-L1 blockade on triple negative breast cancer cells using fourier transform infrared spectroscopy

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    Interactions between programmed death-1 (PD-1) with its ligand PD-L1 on tumor cells can antagonize T cell responses. Inhibiting these interactions using immune checkpoint inhibitors has shown promise in cancer immunotherapy. MDA-MB-231 is a triple negative breast cancer cell line that expresses PD-L1. In this study, we investigated the biochemical changes in MDA-MB-231 cells following treatment with atezolizumab, a specific PD-L1 blocker. Our readouts were Fourier Transform Infrared (FTIR) spectroscopy and flow cytometric analyses. Chemometrical analysis, such as principal component analysis (PCA), was applied to delineate the spectral differences. We were able to identify the chemical alterations in both protein and lipid structure of the treated cells. We found that there was a shift from random coil and ?-helical structure to ?-sheet conformation of PD-L1 on tumor cells due to atezolizumab treatment, which could hinder binding with its receptors on immune cells, ensuring sustained T cell activation for potent immune responses. This work provides novel information about the effects of atezolizumab at molecular and cellular levels. FTIR bio-spectroscopy, in combination with chemometric analyses, may expedite research and offer new approaches for cancer immunology. - 2019 by the authors. Licensee MDPI, Basel, Switzerland.Diabetes Research Center, Qatar Biomedical Research Institute (QBRI), Hamad Bin Khalifa University (HBKU), Qatar Foundation (QF), P.O. Box 34110 Doha, Qatar Cancer Research Center, Qatar Biomedical Research Institute (QBRI), Hamad Bin Khalifa University (HBKU), Qatar Foundation (QF), P.O. Box 34110 Doha, Qatar Department of Chemistry and Earth Sciences, Qatar University (QU), P.O. Box 2713 Doha, Qatar Qatar Computing Research Institute, Hamad Bin Khalifa University (HBKU), Qatar Foundation (QF), P.O. Box 34110 Doha, Qatar Qatar Environment & Energy Research Institute (QEERI), Hamad Bin Khalifa University (HBKU), Qatar Foundation (QF), P.O. Box 34110 Doha, Qatar Correspondence: [email protected] (M.H.M.A.); [email protected] (E.E.

    Evaluation of the level of Some Heavy Metals in Tobacco of Domestic and Imported Cigarette Brands Used in Iraq

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    Smoking-related diseases can be attributed to the inhalation of many different toxins, including heavy metals, which have a host of harmful health effects. The primary objective of this study was to determine whether local and imported cigarette brands used in Iraq , have they elevated levels of metals or not .Three metals Lead (Pb) , Cadmium (Cd) and Chromium(Cr) were determined in tobacco of seventeen brands of imported cigarettes commonly available in Iraq and three Iraqi domestic cigarettes , which were randomly taken from retail market in Baghdad by using flame atomic absorption spectrometry. The produced data of imported and local cigarette brands were discussed and compared together and with studies from elsewhere .The results obtained showed that mean concentrations of lead for all cigarette brands was 5.87 ?g/g dry weight (range 2.27-11,67 ?g/g) , cadmium 0.57?g/g dry weight (range 0.1-1.57 ?g/g) and chromium 3.77?g/g dry weight (range 0.0-11.21 ?g/g) ..There was a large variability in Pb, Cd and Cr content of samples of cigarettes. Pb concentration was the highest, followed by Cr while Cd was the lowest. The investigation confirmed that most of the Iraqi and imported cigarettes in Iraq are contaminated with Pb, Cd, and Cr and quantitatively their distribution is clearly above the safer limits of WHO

    POTENTIAL ROLE OF HAEMATOCOCCUS PLUVIALIS AGAINST DIABETES INDUCED OXIDATIVE STRESS AND INFLAMMATION IN RATS

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    Objective: The aim of this study is to investigate the impact of Haematococcus pluvialis extract against oxidative stress and inflammatory cytokines induced by hyperglycemia in diabetic rats.Methods: Oxidative stress; lipid peroxide (as presented by Malondialdehyde; MDA) and nitric oxide (NO), beside total antioxidant capacity, enzymatic and non-enzymatic antioxidants including reduced glutathione, glutathione peroxidase, and glutathione reductase were evaluated. The inflammatory cytokines; tumor necrosis factor-alpha and interleukin-1 beta were also investigated in rats' serum. Several analyses including expression of antioxidant enzyme related genes, reactive oxygen species (ROS) formation and DNA adducts were performed.Results: The results showed that diabetes mellitus induced-rats exhibited increase in oxidative stress biomarkers and inflammatory cytokines, lower expression levels of the antioxidant enzyme genes; superoxide dismutase and glutathione S-transferase than those in control rats. In addition, diabetic rats exhibited significantly higher levels of ROS generation and 8-hydroxy-2'-deoxyguanosine (8-OHdG) formation. In contrary, supplementation of diabetic rats with H. pluvialis extract improved the negative effect of the hyperglycemia on antioxidant enzymes, the gene expression of antioxidant enzymes, and ROS generation as well as 8-OHdG formation.Conclusion: H. pluvialis extract decreased the oxidative stress, enhanced antioxidant status and inflammatory cytokines induced by hyperglycemia in diabetic rats. The effect of H. pluvialis extract involved in the increase of expression levels of antioxidant enzyme genes; decreased the levels of ROS generation and 8-OHdG formation which may be attributed to the presence of astaxanthin in H. pluvialis extract.Keywords: Haematococcus pluvialis, Hyperglycemia, Diabetes mellitus, Oxidative stress, Inflammatory cytokines, DNA adducts
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