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Asyut, Egypt

Assiut University is an university located in Assiut, Egypt. Assiut University was established in October 1957 as the first university in Upper Egypt. Wikipedia.

Abdo M.A.B.,Assiut University
Engineering Structures

Among different approaches developed for structural damage detection, changes in the measured static response have shown promise for locating structural damage. In this paper, an analytical study of the relationship between damage characteristics (location and severity) and changes in displacement curvatures is presented. Then a parametric study is carried out on using changes in displacement curvatures in structural damage detection. The influence of many parameters are investigated and applied numerically to two examples; an overhanging beam (statically determinate structure) and a two-span continuous beam (statically indeterminate structure) with different damage characteristics. The numerical results clarify that the displacement curvature, has the characteristic of localization at the damaged region. Also, the obtained results show that the displacement curvature, derived from static response only, can accurately locate single and multiple damages with different damage characteristics for specific load case. The merits as well as the disadvantages of using displacement curvature in structural damage detection are also discussed. © 2011 Elsevier Ltd. Source

Abdel-Aleem H.,Assiut University
The Cochrane database of systematic reviews

Preterm birth is a major health problem and contributes to more than 50% of the overall perinatal mortality. Preterm birth has multiple risk factors including cervical incompetence and multiple pregnancy. Different management strategies have been tried to prevent preterm birth, including cervical cerclage. Cervical cerclage is an invasive technique that needs anaesthesia and may be associated with complications. Moreover, there is still controversy regarding the efficacy and the group of patients that could benefit from this operation. Cervical pessary has been tried as a simple, non-invasive alternative that might replace the above invasive cervical stitch operation to prevent preterm birth. To evaluate the efficacy of cervical pessary for the prevention of preterm birth in women with risk factors for cervical incompetence. We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (1 September 2012), Current Controlled Trials and the Australian New Zealand Clinical Trials Registry (1 September 2012). We selected all published and unpublished randomised clinical trials comparing the use of cervical pessary with cervical cerclage or expectant management for prevention of preterm birth. We did not include quasi-randomised trials. Cluster-randomised or cross-over trials were not eligible for inclusion. Two review authors independently assessed trials for inclusion. The review included one randomised controlled trial. The study included 385 pregnant women with a short cervix of 25 mm or less who were between 18 to 22 weeks of pregnancy. The use of cervical pessary (192 women) was associated with a statistically significantly decrease in the incidence of spontaneous preterm birth less than 37 weeks' gestation compared with expectant management (22% versus 59 %; respectively, risk ratio (RR) 0.36, 95% confidence interval (CI) 0.27 to 0.49). Spontaneous preterm birth before 34 weeks was statistically significantly reduced in the pessary group (6% and 27% respectively, RR 0.24; 95% CI 0.13 to 0.43). Mean gestational age at delivery was 37.7 + 2 weeks in the pessary group and 34.9 + 4 weeks in the expectant group. Women in the pessary group used less tocolytics (RR 0.63; 95% CI 0.50 to 0.81) and corticosteroids (RR 0.66; 95% CI 0.54 to 0.81) than the expectant group. Vaginal discharge was more common in the pessary group (RR 2.18; 95% CI 1.87 to 2.54). Among the pessary group, 27 women needed pessary repositioning without removal and there was one case of pessary removal. Ninety-five per cent of women in the pessary group would recommend this intervention to other people. Neonatal paediatric care admission was reduced in the pessary group in comparison to the expectant group (RR 0.17; 95% CI 0.07 to 0.42). The review included only one well-designed randomised clinical trial that showed beneficial effect of cervical pessary in reducing preterm birth in women with a short cervix. There is a need for more trials in different settings (developed and developing countries), and with different risk factors including multiple pregnancy. Source

This paper presents survey about Fault Ride Through (FRT) techniques and controllers which employed with all wind generation system types. After presenting a comprehensive FRT survey, paper proposes three Fault Ride Through (FRT) controllers for keeping stability of Fixed Speed Wind Generation (FSWG) system serving in isolated Micro-Grid (MG). The first controller has been implemented by inserting Superconductor Fault Current Limiter (SFCL) in series with wind generator terminals during fault instant. The second proposed FRT controller is modifying the conventional Pitch Angle Controllers (PAC) to can spill and reduce high percentage of extracted mechanical wind power during and subsequent fault occurrence which in turns help stability improvement and restoration. Third FRT technique is performed by adapting the wind turbine gearbox ratio which forces the wind generation system to run far from the maximum power point. The best performance is obtained with the SFCL controller. Superior results are obtained when the three proposed FRT controllers are employed simultaneously. The three developed FRT controllers are simple, reliable and economical attractive. Effects of fault type on SFCL FRT controller performance are analyzed and investigated in details. The proposed SFCL FRT controller has been tested under single phase, double phase, phase to phase, and three phases to ground faults. Results display that the three phases to ground fault is the most severe type on SFCL FRT performance from stability point of view. On the other hand, double phase to ground fault is the most severe one from fluctuations and oscillations points of view. Parameters of the SFCL must be adjusted based on the three phases to ground fault. If the SFCL FRT controller is designed to can deal with three phases fault, it sure can deal with the other fault types successfully. © 2014 Elsevier Ltd. Source

Elsabahy M.,Texas A&M University | Elsabahy M.,Assiut University | Wooley K.L.,Texas A&M University
Chemical Society Reviews

Nanoscale objects, whether of biologic origin or synthetically created, are being developed into devices for a variety of bionanotechnology diagnostic and pharmaceutical applications. However, the potential immunotoxicity of these nanomaterials and mechanisms by which they may induce adverse reactions have not received sufficient attention. Nanomaterials, depending on their characteristics and compositions, can interact with the immune system in several ways and either enhance or suppress immune system function. Cytokines perform pleiotropic functions to mediate and regulate the immune response and are generally recognized as biomarkers of immunotoxicity. While the specificity and validity of certain cytokines as markers of adverse immune response has been established for chemicals, small and macromolecular drugs, research on their applicability for predicting and monitoring the immunotoxicity of engineered nanomaterials is still ongoing. The goal of this review is to provide guidelines as to important cytokines that can be utilized for evaluating the immunotoxicity of nanomaterials and to highlight the role of those cytokines in mediating adverse reactions, which is of particular importance for the clinical development of nanopharmaceuticals and other nanotechnology-based products. Importantly, the rational design of nanomaterials of low immunotoxicity will be discussed, focusing on synthetic nanodevices, with emphasis on both the nanoparticle-forming materials and the embedded cargoes. © 2013 The Royal Society of Chemistry. Source

Elsabahy M.,Texas A&M University | Elsabahy M.,Assiut University | Wooley K.L.,Texas A&M University
Chemical Society Reviews

Polymeric nanoparticles-based therapeutics show great promise in the treatment of a wide range of diseases, due to the flexibility in which their structures can be modified, with intricate definition over their compositions, structures and properties. Advances in polymerization chemistries and the application of reactive, efficient and orthogonal chemical modification reactions have enabled the engineering of multifunctional polymeric nanoparticles with precise control over the architectures of the individual polymer components, to direct their assembly and subsequent transformations into nanoparticles of selective overall shapes, sizes, internal morphologies, external surface charges and functionalizations. In addition, incorporation of certain functionalities can modulate the responsiveness of these nanostructures to specific stimuli through the use of remote activation. Furthermore, they can be equipped with smart components to allow their delivery beyond certain biological barriers, such as skin, mucus, blood, extracellular matrix, cellular and subcellular organelles. This tutorial review highlights the importance of well-defined chemistries, with detailed ties to specific biological hurdles and opportunities, in the design of nanostructures for various biomedical delivery applications. © 2012 The Royal Society of Chemistry. Source

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