Elsherbiny N.M.,Mansoura University
Inflammation & allergy drug targets | Year: 2013
Diabetes is one of the risk factors to human health, which progressively leads to renal complications known as diabetic nephropathy. Many previous studies illustrated biochemical and morphological abnormalities in various animal models of diabetic nephropathy, which may be attributed to altered action of adenosine, an endogenous purine nucleoside released from various tissues and organs. Adenosine is a potent autocrine anti-inflammatory and immunosuppressive molecule that is released from cells into the extracellular space at sites of inflammation and tissue injury. This review will give a general overview of the adenosine receptors and focuses on their role in diabetes nephropathy. The insight into the signaling pathway through adenosine receptors could be helpful in developing novel therapeutic tools to regulate the pathophysiological conditions that arise progressively in diabetes.
El-Haddad M.N.,Mansoura University
Carbohydrate Polymers | Year: 2014
The inhibition effect of hydroxyethylcellulose (HEC) on 1018 c-steel corrosion in 3.5% NaCl solution was investigated by using potentiodynamic polarization, electrochemical frequency modulation (EFM) and electrochemical impedance spectroscopy (EIS) techniques. The potentiodynamic polarization studies suggested that HEC acts as a mixed-type inhibitor. Data obtained from EIS were analyzed to model the corrosion inhibition process through equivalent circuit. Results obtained from EFM technique were shown to be in agreement with potentiodynamic and EIS techniques. The adsorption behavior of HEC on steel surface follows the Langmuir adsorption isotherm. Thermodynamic parameter (ΔG°ads) and activation parameters (Ea*, ΔH* and ΔS*) were calculated to investigate mechanism of inhibition. Scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) analysis system were performed to characterize the film formed on the metal surface. DMol3 quantum chemical calculations were performed to support the adsorption mechanism with the structure of HEC molecule. © 2014 The Authors. Published by Elsevier Ltd.
Elshafei E.A.M.,Mansoura University
Energy | Year: 2010
Experiments were performed on natural convection heat transfer from circular pin fin heat sinks subject to the influence of its geometry, heat flux and orientation. The geometric dependence of heat dissipation from heat sinks of widely spaced solid and hollow/perforated circular pin fins with staggered combination, fitted into a heated base of fixed area is discussed. Over the tested range of Rayleigh number, 3.8×106≤Ra≤1.65×107, it was found that the solid pin fin heat sink performance for upward and sideward orientations shows a competitive nature, depending on Rayleigh number and generally shows higher heat transfer coefficients than those of the perforated/hollow pin fin ones in both arrangement. For all tested hollow/perforated pin fin heat sinks, however, the performance for sideward facing orientation was better than that for upward facing orientation. This argument is supported by observing that the augmentation factor was around 1.05-1.11, depending on the hollow pin diameter ratio, Di/Do. Meanwhile, the heat sink of larger hollow pin diameter ratio, Di/. Do offered higher heat transfer coefficient than that of smaller Di/Do for upward orientation, and the situation was reversed for sideward orientation. The heat transfer performance for heat sinks with hollow/perforated pin fins was better than that of solid pins. The temperature difference between the base plate and surrounding air of these heat sinks was less than that of solid pin one and improved with increasing Di/Do. © 2010.
Elalami M.E.,Mansoura University
Knowledge-Based Systems | Year: 2011
This paper presents a proposed model for content-based image retrieval (CBIR) which depends only on extracting the most relevant features according to a feature selection technique. The suggested feature selection technique aims at selecting the optimal features that not only maximize the detection rate but also simplify the computation of the image retrieval process. The proposed model is divided into three main techniques, the first one is concerned with the features extraction from images database, the second is performing feature discrimination, and the third is concerned with the feature selection from the original ones. As for the first technique, the 3D color histogram and the Gabor filter algorithm are used to extract the color and texture features respectively. While the second technique depends on a genetic algorithm (GA) for replacing numerical features with nominal features that represent intervals of numerical domains with discrete values. The GA is utilized in this technique to obtain the optimal boundaries of these intervals, and consequently to reduce the complexity in feature space. In the third technique, the feature selection performs two successive functions which are called preliminary and deeply reduction for extracting the most relevant features from the original features set. Indeed, the main contribution of the proposed model is providing a precise image retrieval in a short time. © 2010 Elsevier B.V. All rights reserved.
Elnaghy A.M.,Mansoura University
International Endodontic Journal | Year: 2014
Aim: To investigate the effect of QMix irrigant compared with several other irrigating solutions on the bond strength of glass fibre posts to root dentine and on smear layer removal after post space preparation. Methodology: One hundred and fifty single-rooted teeth were used. The specimens were divided into six groups in each test according to the irrigation regimen used: group 1, distilled water; group 2, 5.25% sodium hypochlorite (NaOCl); group 3, 2% chlorhexidine digluconate (CHX); group 4, 17% ethylenediaminetetraacetic acid (EDTA); group 5, 17% EDTA followed by 2% CHX; and group 6, QMix. Dual-cure self-adhesive resin cement (i CEM; Heraeus Kulzer, Hanau, Germany) was used for testing the adhesion of glass fibre post (Reblida; VOCO, Cuxhaven, Germany) to root dentine using a micropush-out test. Debonding specimens were examined with a scanning electron microscope. Scanning electron microscopy was also used to examine and score the treated specimens for debris removal and dentinal tubule opening. Micropush-out data were analysed using anova and Tukey's test. Debris and dentinal tubule opening scores were analysed with the Kruskal-Wallis and Mann-Whitney U-tests. Results: QMix and 17% EDTA/2% CHX demonstrated the highest mean bond strength values in all root levels amongst the groups. Most failure modes were adhesive type of failures between post and luting material (42.6%). QMix, 17% EDTA and 17% EDTA/2% CHX performed significantly better than the other groups on smear layer removal and dentinal tubule opening. Conclusion: QMix is an effective irrigant that can remove smear layer, open dentinal tubules and simplify the irrigation protocol, without compromising the bonding strength of glass fibre posts cemented with a self-adhesive resin cement to root dentine. © 2013 International Endodontic Journal.