143 research outputs found

    Scalability Aware Energy Consumption and Dissipation Models for Wireless Sensor Networks

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    Most of Wireless Sensor Networks researches focus on reducing the amount of energy consumed by nodes and network to increase the network lifetime. Thus, several papers have been presented and published to optimize energy consumption in each area of WSNs, such as routing, localization, coverage, security, etc. To test and evaluate their propositions, authors apply an energy dissipation model; this model must be more realistic and suitable to give good results. In this paper we present a general preview on different sources of energy consumption in wireless sensor networks, and provide a comparative study between two energy models used in WSNs that offer an effective and an adequate tool for researchers

    Routine versus selective plasma exchange before thymectomy in myasthenia gravis

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    Background: Prethymectomy plasma exchange may improve the outcome of surgery; however, the technique is associated with an increased risk of complications. Therefore, the objective of this study was to compare selective versus routine plasma exchange before thymectomy in patients with myasthenia gravis. Method: We conducted a prospective multi-center cohort study to compare two protocols for plasma exchange before thymectomy. We compared the routine plasma exchange in all patients undergoing thymectomy for myasthenia gravis (group I; n= 30) versus selective exchange (Group II; n= 30). Endpoints were the duration of postoperative mechanical ventilation, plasma exchange, and operative complications. Results: There was no difference in age between both groups (30± 10.1 vs. 29± 9.2 years in Group I and II, respectively; p= 0.69). There were 17 females in Group I (56.67%) vs. 16 in group II (53.33%) (p= 0.8). Comorbidities are comparable between groups. All patients preoperative pyridostigmine, and 27 patients (90%) in Group I and 26 patients (87%) in Group II received glucocorticoids. There was no difference in pulmonary function tests between groups. Plasma exchange related complications were not different between groups. Immediate extubation was achieved in 29 patients (97%) in Group II, and after 6 hours in one patient (3.33%). In Group I, 28 patients (93%) extubated immediately, and two patients were ventilated for 7-12 hours. The mean ICU stay was 1.5 days in Group I and 1.4 days in group II (p= 0.615). The mean hospital stay was 8.5 days in Group I and 9.2 days in group II (p= 0.118). There was no significant difference in pathology between groups (p= 0.137). Conclusion: Selective plasma exchange is feasible before thymectomy for myasthenia gravis. Selective plasma exchange may decrease exchange related complications without affecting the operative outcomes

    The Role of CD 34 Hematopoietic Progenitor Cells, Macrophages, and Smooth Muscle Cells in Human Coronary Artery Atherogenesis

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    BACKGROUND: Atherosclerosis is a widespread and devastating disease and one of the leading causes of death worldwide. So much is there to understand about atherosclerosis. And although a lot is already discovered, yet most of the studies are performed in cell cultures and animal models. Recent technologies for genetic engineering and imaging are mainly performed on animal models, with few studies in human tissues. A better understanding of their role is required. AIM: We aim to study the expression of CD 34 hematopoietic progenitor stem cell, CD 68 macrophages, and smooth muscle actin (SMA)-positive smooth muscle cells (SMCs) in the human coronary arteries and correlate their differential expression with the atherosclerosis progression. RESULTS: CD 68 and CD 34 expression increase as the atherosclerotic process proceeds from early atheroma to advanced atheroma and start to decrease as the process proceeds to fibroatheroma with a significant p < 0.001. Conversely, SMA expression decreases as the atherosclerotic process progresses with a significant p < 0.001. CONCLUSION: CD34 progenitor cells in conjunction with CD 68 macrophages have a major role in the development of atherosclerosis, whereas the SMCs are minimal in the early stages and reach their maximal levels during the stage of fibroatheroma

    Role of nanoparticles in diagnosis and management of parasitic diseases: Review article

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    Background: An extensive class of materials, nanoparticles (NPs) include particulate compounds with a minimum diameter of 100 nanometers (nm). This is because of their tiny size and huge surface area, which allows them to traverse the blood-brain barrier, enter the respiratory system and be adsorbable through endothelial cells. Today, nanoparticles for drug administration are being studied to increase their sustained release, intracellular penetrability as well as bioavailability, due to the constant development and innovation of nanomedicine.Objective: To determine how nanoparticles can help diagnose and treat parasitic diseases.Conclusion: Nanoparticles could be conjugated with proteins and immunoglobulins that could help in specific diagnosis of several parasitic diseases, in addition, improved efficacy and reduced harmful side effects can be achieved by immobilizing antiparasitic medicines on or inside nanomaterials

    PROTECTIVE EFFECT OF MORINGA PEREGRINA LEAVES EXTRACT ON ACETAMINOPHEN - INDUCED LIVER TOXICITY IN ALBINO RATS.

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    Background: Acetaminophen is a common antipyretic drug but at overdose can cause severe hepatotoxicity that may further develop into liver failure and hepatic centrilobular necrosis in experimental animals and humans. This study was undertaken to assess the ameliorative role of Moringa peregrina leaves extract against acetaminophen toxicity in rats. Materials and methods: Induction of hepatotoxicity was done by chronic oral administration of acetaminophen (750 mg/kg bwt) for 4 weeks. To study the possible hepatoprotective effect, Moringa peregrina leaves extract (200 mg/kg bwt) or Silymarin (50 mg/kg bwt) was administered orally, for 4 weeks, along with acetaminophen. Results: acetaminophen significantly increased serum liver enzymes and caused oxidative stress, evidenced by significantly increased tissue malondialdehyde, glutathione peroxidase, hepatic DNA fragmentation, and significant decrease of glutathione and antioxidant enzymes in liver, blood and brain. On the other hand, administration of Moringa peregrina leaves extract reversed acetaminophen-related toxic effects through: powerful malondialdehyde suppression, glutathione peroxidase normalization and stimulation of the cellular antioxidants synthesis represented by significant increase of glutathione, catalase and superoxide dismutase in liver, blood and brain, besides, DNA fragmentation was significantly decreased in the liver tissue. Conclusion: acetaminophen induced oxidative damage can be improved by Moringa peregrina leaves extracttreatment, due to its antioxidant potential

    Biological activity and chemical identification of ornithine lipid produced by Burkholderia gladioli pv. agaricicola ICMP 11096 using LC-MS and NMR analyses

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    Lipoamino acids (LAs) have been isolated from bacterial species and are included among the most important microbial secondary metabolites. Some synthetic LAs are being increasingly used in pharmaceutical applications such as ornithine lipid (OL) which is present in relatively large amounts in some G-ve bacteria. Many Burkholderia spp. produce in vitro secondary metabolites with lipodepsipeptide nature and have showed relevant biological activities and potential practical applications. The purposes of this research were i) to study the antibacterial activity of cell-free culture filtrate of B. gladioli pv. agaricicola strain ICMP 11096; ii) HPLC fractionation and antibacterial evaluation of isolated compounds; iii) Finally, the identification by LC-MS and NMR analysis of the principle bioactive compound produced by the bacterium. Results showed that the cell-free culture filtrate has a promising antibacterial activity against the two studied target microorganisms. In addition, HPLC fractionation demonstrated the presence of five single bioactive compounds produced by the bacterium and their antibacterial activity stated that peak no. 2 is the most bioactive one against B. megaterium and E. coli. Successively, the principal bioactive compound was identified by LC-MS and ¹H NMR as OL with mass spectrum (m/z) 719. This research is considered the first report of isolation and chemical identification of OL compound isolated from B. gladioli pv. agaricicola ICMP 11096

    Theoretical development of biaxial fabric prestressed composites under tension-tension fatigue loading

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    The improvement of the composite material against fatigue loading is of a great interest. In this study, the classical lamination theory of laminated composite was developed in order to include the effect of fibre prestressing on the composite's fatigue life when it was subjected to tension-tension fatigue loading. The biaxial fabric prestress term of the plain-weave composite (E-glass/polyester) was included in the theory and simplified. The overall tensile stress within the composite lamina was reduced by inducing compressive residual stress imparted from releasing the fibre pretension load. The fatigue life of the prestressed E-glass/polyester composite lamina was prolonged 36 times compared to the non-prestressed counterparts when the fabric was biaxially prestressed with 100 MPa
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