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Ahmed R.A.,Taif University | Ahmed R.A.,Forensic Chemistry Laboratories | Fadl-Allah S.A.,Taif University | Fadl-Allah S.A.,Cairo University | And 4 more authors.
Applied Surface Science | Year: 2014

Biocomposite consists of gold nanoparticles (AuNPs) and a natural polymer as Chitosan (CS) was electrodeposited over NiTi alloy to improve biocompatibility, biostability, surface corrosion resistance and antibacterial effect for orthopedic implantation. The forming process and surface morphology of this biocomposite coats over NiTi alloy were studied. The results showed that the nm-scale gold particles were embedded in the composite forming compact, thick and smooth coat. Elemental analysis revealed significant less Ni ion release from the coated NiTi alloy compared with the uncoated one by 20 fold. Furthermore, the electrochemical corrosion measurements indicated that AuNPs/CS composite coat was effective for improving corrosion resistance in different immersion times and at all pH values, which suggests that the coated NiTi alloys have potential for orthopedic applications. Additionally, the efficiencies of the biocomposite coats for inhibiting bacterial growth indicate high antibacterial effect. © 2013 Elsevier B.V. Source


Gad El-Rab S.M.F.,Taif University | Gad El-Rab S.M.F.,Asuit University | Fadl-Allah S.A.,Taif University | Fadl-Allah S.A.,Cairo University | And 2 more authors.
Applied Surface Science | Year: 2012

Titanium metal (Ti) with antibacterial function was successfully developed in the present study by electrodeposition of biomimetic Ca-P coat in simple supersaturated calcium and phosphate solution (SCPS). The electrochemical behavior and corrosion resistance of Ca-P deposited on anodized titanium (AT) have been investigated in SCPS by using electrochemical impedance spectroscopy (EIS). The plate-counting method was used to evaluate the antibacterial performance against Staphylococcus aureus (ATCC6538). In vitro antibacterial activity study indicated a significantly reduced number of bacteria S. aureus on Ca-P/AT plate surface when compared with that on Ti or AT surfaces and the corresponding antibacterial mechanism is discussed. The morphology and chemical structure of different titanium samples were systematically investigated by scanning electron microscope (SEM) and energy dispersive X-ray analysis (EDX). The study confirmed that the antibacterial properties of the samples were related to chemical composition of sample surface. © 2012 Elsevier B.V. All rights reserved. Source


Fadlallah S.A.,Taif University | Fadlallah S.A.,Cairo University | El-Bagoury N.,Taif University | El-Bagoury N.,Central Metallurgical Research and Development Institute | And 5 more authors.
Journal of Alloys and Compounds | Year: 2014

Nowadays, Nickel-titanium nearly equiatomic is considered as one of the best biomaterials. The aim of the present work deals with the evolution of the electrochemical behavior of NiTi in simulated oral environment. The hardness, microstructures corrosion resistance and antibacterial performance of NiTi alloy were compared with pure titanium. The hardness of NiTi is twice the hardness of pure titanium. Electrochemical techniques were used to detect the corrosion resistance of both biomaterials in Hank's solution containing (-)-epigallocatechin gallate (EGCG) which used to simulate the oral environment. In the physiological solution selected for the present study, the impedance spectroscopy (EIS) results showed that EGCG sharply increase the corrosion resistance of NiTi from 129 kΩ cm2 to 1.10 T Ω cm 2 while slowly increase the corrosion resistance of pure titanium from 9.4 kΩ cm2 to 11.3 kΩ cm2 during the duration time of immersion at 37 C. The plate-counting method was used to evaluate the antibacterial performance against Staphylococcus aureus (ATCC 6538). Among the two specimens of biomaterials studied, the antibacterial performance results revealed that the NiTi alloy is better than the pure titanium. The morphology and chemical structure of NiTi and Ti samples were systematically investigated by scanning electron microscope (SEM) and energy dispersive X-ray analysis (EDX). The study confirmed that the distinctive characteristics of the NiTi alloy back to its chemical composition with two phases from nickel and titanium. © 2013 Elsevier B.V. All rights reserved. Source


Osman A.M.G.,University of Mississippi | Abourashed E.A.,Chicago State University | Slade D.,MRI Global | Ahmed S.A.,Suez Canal University | And 8 more authors.
Medicinal Chemistry Research | Year: 2015

Ferutinin (1), the major constituent of Ferula hermonis and other Ferula species, is a sesquiterpene ester with remarkable estrogenic activity, beside other valuable medicinal properties. To investigate the influence of chemical modification of the ferutinin structure on its estrogenic effect and binding affinity toward the cannabinoid CB1 and CB2 receptors, twelve derivatives of 1 were prepared and evaluated in vitro, together with the parent compound, for the respective bioactivities, based on the recent evidence for estrogen-endocannabinoid interaction. Nine of the prepared derivatives (3-11) are new semisynthetic esters of 1. The parent compound ferutinin (1) exhibited the highest level of estrogenic activity (EC50 0.3 μM and a percent maximal 17β-estradiol response of 90 % at 1 μM). Compound 6 was found to be a selective agonist for CB2 receptor (EC50 0.051 μM, Ki 0.025 μM), with much less affinity for CB1 receptor (EC50 97 μM, Ki 48.5 μM). Compound 8 was a selective agonist for CB1 (EC50 62, Ki 0.031 μM) with no affinity toward CB2. © 2015 Springer Science+Business Media. Source


Ali H.F.M.,Alexandria University | Bab A.M.R.F.E.,Asuit University | Zyada Z.,University of Technology Malaysia | Zyada Z.,Tanta University | Megahed S.M.,Alexandria University
2015 10th Asian Control Conference: Emerging Control Techniques for a Sustainable World, ASCC 2015 | Year: 2015

Many places in the world are contaminated with Landmines, normally buried under shallow or deep layers of sand and mud, which causes landmine detection and/or removal to be challenging tasks. To design a reliable landmine sensing system some deep analysis and many test cases are required. In this paper, existence of landmine under the ground surface is examined and its inclination angle effect on detection is analyzed applying finite element method and artificial neural networks. Inverse analyses are used to produce 'forward results'. Applying a contact pressure (lower than the expected landmine activation pressure) on the ground containing a landmine under its surface would produce a pressure distribution that is dependent on the landmine type, depth and inclination. COMSOL Multi-physics is applied to model sandy soil contaminated by two landmines of different types at different depths and surface pressure distribution is obtained applying external pressure load of 1kPa. Three NNs are trained applying the obtained surface pressure distribution data. The first NN is of perceptron type which classifies the introduced objects in sand. The other two NNs are of feed-forward NN type and are developed for estimating depths of two landmines of different types, one for each. The Landmine inclination angles (0°-30°) effect on detection rate is studied. The results are tabulated and justified. The results show that the anti-tank landmine is fully detected, while the anti-personnel landmine is only detected with a rate of 75%. It is also shown that landmine characteristics estimation is reliable when its inclination angle is small. © 2015 IEEE. Source

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