Al Fayyum, Egypt
Al Fayyum, Egypt

Fayoum University is a public university located in the Egyptian city of Al Fayoum in northern Egypt. From 1976 to 2005, Fayoum University was a public institution within the University of Cairo. In August 2005, it was established as an independent campus with 2,000 faculty members and enrollment of about 25. 000 students. The city of Fayoum is an oasis located approximately 63 miles southwest of Cairo and is noted for its agricultural production and tourism. Wikipedia.

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Long-term intermittent hypoxia (IH) is a characteristic hallmark of obstructive sleep apnea (OSA) and causes most of the neurological aspects of OSA, such as spatial memory and learning deficits. These deficits are accompanied by an increase in oxidative stress and inflammation in brain areas involved in cognition, such as the hippocampus, particularly in children. Resveratrol is a natural polyphenolic compound with potent antioxidant, anti-inflammatory and neuroprotective properties. Aim: The aim of this work is to study the possible protective effect of resveratrol against IH-induced neurobehavioral deficits and to investigate the possible mechanism of this protective effect in the young rat model of OSA. Methods: The effect of resveratrol (5 and 10 mg/kg, orally) on anxiety, spatial memory and learning deficits in young rats exposed to IH for 6 weeks and the corresponding biochemical changes were studied. Results: Resveratrol attenuated IH-induced anxiety and spatial memory deficits, as indicated by the elevated plus maze and Morris water maze tests, respectively, in a dose-dependent manner. In addition, resveratrol antagonized IH-induced increases in hippocampal glutamate, TBARS and 8-OHdG levels and p47Phox expression and decreases in GSH levels and GSH-Px activity in the hippocampus of IH-exposed young rats. Conclusion: Resveratrol ameliorates IH-induced anxiety and spatial learning deficits through multiple beneficial effects on hippocampal oxidative pathways that involve decreased expression of the p47Phox subunit of NADPH oxidase. Hence, the potential therapeutic role of resveratrol in OSA may be utilized in the near future and deserves further exploration. © 2016 Elsevier B.V..

Ibrahim W.M.,Fayoum University
Journal of Hazardous Materials | Year: 2011

Biosorption is an effective process for the removal and recovery of heavy metal ions from aqueous solutions. The biomass of marine algae has been reported to have high biosorption capacities for a number of heavy metal ions. In this study, four species of red seaweeds Corallina mediterranea, Galaxaura oblongata, Jania rubens and Pterocladia capillacea were examined to remove Co(II), Cd(II), Cr(III) and Pb(II) ions from aqueous solution. The experimental parameters that affect the biosorption process such as pH, contact time and biomass dosage were studied. The maximum biosorption capacity of metal ions was 105.2. mg/g at biomass dosage 10. g/L, pH 5 and contact time 60. min. The biosorption efficiency of algal biomass for the removal of heavy metal ions from industrial wastewater was evaluated for two successive cycles. Galaxaura oblongata biomass was relatively more efficient to remove metal ions with mean biosorption efficiency of 84%. This study demonstrated that these seaweeds constitute a promising, efficient, cheap and biodegradable sorbent biomaterial for lowering the heavy metal pollution in the environment. © 2011 Elsevier B.V.

Abdel-Karim M.,Fayoum University
European Journal of Mechanics, A/Solids | Year: 2011

In order to identify different variables that affect ratchetting simulations, variation of elastic modulus during loading and unloading is considered and discussed based on the experimental observations which pointed out by Morestin and Boivin (1996), Ishikawa (1997), Cleveland and Ghosh (2002), Zhou et al. (2005) and recently by Khan et al. (2009a,b,c). Then the effect of such variation on simulations is scrutinized from the theoretical point of view by considering simulations of ratchetting experiments conducted on stainless steel 304L by Hassan et al. (2008) using the well-known Armstrong-Frederick model. It is shown that, using two different values for the elastic modulus during loading and unloading could have a significant effect on simulations of uniaxial ratchetting. On the other hand, such significant effect hardly occurs in the case of simulations of biaxial ratchetting experiments under consideration. The importance of such findings is that the excessive ratchetting over-prediction resulting from any specific kinematic hardening rule is expected to decrease significantly by taking into consideration this effect. In this case, modeling of kinematic hardening rules could necessitate more attention and reconsideration. © 2010 Elsevier Masson SAS. All rights reserved.

El Sayed A.M.,Fayoum University
Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms | Year: 2014

Carboxymethyl cellulose (CMC)/Polyvinyl alcohol (PVA) blend films were prepared by solution casting method. Then, these films were irradiated with γ-rays from a Co-60 source at doses over the range 0-70 kGy to investigate the modifications induced in the optical and dielectric properties. The dielectric constant (ε′) was measured in the temperature range 303-408 K and in the frequency range 10 kHz-1 MHz. The indirect optical band gap was found to increase within the dose range 0-10 kGy, and to decrease at the higher doses. The refractive index values, however, showed a reversed behavior. The highest transmittance percentage was obtained at 10 kGy dose. According to the frequency and temperature dependence of ε′, α- relaxation peaks were observed in all samples and assigned to the micro-Brownian motion of the blend chains. The values of É showed a decrease in the dose range 0-10 kGy and an increase in the dose range 10-70 kGy. The ac conductivity σac (T) showed an Arrhenius type behavior separated into two distinct regions. The results of the present system are compared with those of similar materials. © 2013 Elsevier B.V. All rights reserved.

Hassan A.M.S.,Fayoum University
Phytochemical Analysis | Year: 2012

Introduction Bioautographic assays using TLC play an important role in the search for active compounds from plants. A TLC bioautographic assay has previously been established for the detection of acetylcholinesterase inhibitors but not for lipases. Objective Development of a TLC bioautographic method for detecting lipase inhibitors in plant extracts. Methodology After migration of the plant extracts, the TLC plate was sprayed with α-naphtyl acetate and enzyme solutions before incubation at 37°C for 20 min. Finally, the solution of Fast Blue B salt was sprayed onto the TLC plate giving a purple background colouration. Results Lipase inhibitors were visualised as white spots on the TLC plates. Orlistat (a known lipase inhibitor) inhibited lipase down to 0.01 μg. Methanolic extracts of Camellia sinensis (L.) kuntz and Rosmarinus officinalis L after migration on TLC gave enzymatic inhibition when applied in amounts of 82 and 56 μg, respectively. On the other hand the methanolic extract of Morus alba leaves did not exhibit any lipase inhibitory activity. Conclusion The screening test was able to detect lipase inhibition by pure reference substances and by compounds present in complex matrices, such as plant extracts. Copyright © 2011 John Wiley & Sons, Ltd.

The plants of Phaseolus vulgaris L. were grown in the presence of NaCl and/or CdCl 2 and were sprayed with 5μM of 24-epibrassinolide (EBL) at 15 days after transplanting (DAT) and were sampled at 30 DAT and at the end of experiment. The plants exposed to NaCl and/or CdCl 2 exhibited a significant decline in growth, the level of pigment parameters, green pod yield and pod protein. However, the follow up treatment with EBL detoxified the stress generated by NaCl and/or CdCl 2 and significantly improved the above parameters. The NaCl and/or CdCl 2 increased electrolyte leakage, lipid peroxidation and plant Cd 2+ content, and decreased the membrane stability index (MSI) and relative water content. However, the EBL treatment in absence of the stress improved the MSI and relative water content and minimized plant Cd 2+ content but could not influence electrolyte leakage and lipid peroxidation. The antioxidative enzymes and the level of proline exhibited a significant increase in response to EBL as well as to NaCl and/or CdCl 2 stress. © 2011 Elsevier B.V.

At room temperature, the contact of Tb3+ ions dissolved in bidistilled water with a polystyrene film incorporating 2-pyridone (PS-Pyr) exhibits terbium-sensitized photoluminescence (PL) when excited at 295 nm. The Tb3+-sensitized emission is attributed to a complex formation as well as a highly efficient and selective energy transfer from 2-pyridone to Tb 3+ ions. This has been utilized as the basis for a selective spectrofluorimetric detection of Tb3+. The association constant and the lifetime of the formed complex were determined; also, the sensing mechanism of the optosensor was proposed. The linear response range covers a concentration range of Tb3+ from 5.0 × 10-9 to 1.0 × 10-6 mol L-1. The LOD and LOQ were 2.9 × 10 -9 and 9.7 × 10-9 mol L-1, respectively. The sensitizer exhibits a unique and a highly selective energy transfer towards Tb3+ ions over a large number of interfering ions. Moreover, the proposed optosensor was easy to prepare, has a relatively fast response time ∼30 s and high stability for at least 42 days. The optosensor has been applied to the determination of terbium ion in synthetic samples with high sensitivity, good reproducibility and accuracy. © 2014 Elsevier B.V.

Abdel-Karim M.,Fayoum University
International Journal of Pressure Vessels and Piping | Year: 2010

In this work, an extension of the well-known Ohno-Wang model to incorporate isotropic hardening is presented and discussed. The model is extended by taking into account isotropic hardening depending on accumulated plastic strain. It is assumed that isotropic hardening will be associated with kinematic hardening in the governing equations where activation of either isotropic or kinematic hardening is controlled through a specific controller parameter κ. The accuracy of simulations can be adjusted by changing the value of this controller parameter. It is shown that such an extension is effective and restrains activation of dynamic recovery resulting in less accumulated ratchetting strain with large values of the controller parameter. In addition, it is shown that the extended model simulates multiaxial ratchetting experiments conducted on SS 304L by Hassan et al. fairly well. © 2010 Elsevier Ltd.

Abdel-Karim M.,Fayoum University
International Journal of Plasticity | Year: 2010

This study evaluates the performance of several non-linear kinematic hardening rules in predicting the various biaxial ratchetting experiments of stainless steel (SS) 304L under various stress-controlled histories performed by Hassan et al. (2008). The non-linear kinematic hardening rules proposed by Burlet and Cailletaud (1986), Ohno and Wang (1993, 1994), Abdel-Karim and Ohno (2000), Kang (2004), Chen and Jiao (2004), Chen et al. (2005) and the different rules of Abdel-Karim (2009) are examined and carefully scrutinized. The considered kinematic hardening rules range from the simple classical ones to more detailed rules, which incorporate additional terms and/or parameters to simulate different factors that affect ratchetting. It is shown that none of the examined kinematic hardening rules is general enough to simulate all of the ratchetting responses for the experiments under consideration. © 2009 Elsevier Ltd. All rights reserved.

The effects of bio-regulators salicylic acid (SA) and 24-epibrassinolide (EBL) as seed soaking treatment on the growth traits, content of photosynthetic pigments, proline, relative water content (RWC), electrolyte leakage percent (EC%), antioxidative enzymes and leaf anatomy of Zea mays L. seedlings grown under 60 or 120mM NaCl saline stress were studied. A greenhouse experiment was performed in a completely randomized design with nine treatments [control (treated with tap water); 60mM NaCl; 120mM NaCl; 10-4M SA; 60mM NaCl+10-4M SA; 120mM NaCl+10-4M SA; 10μM EBL; 60mM NaCl+10μMEBL or 120mM NaCl+10μM EBL] each with four replicates. The results indicated that NaCl stress significantly reduced plant growth traits, leaf photosynthetic pigment, soluble sugars, RWC%, and activities of catalase (CAT), peroxidase (POX) as well as leaf anatomy. However, the application of SA or EBL mitigated the toxic effects of NaCl stress on maize seedlings and considerably improved growth traits, photosynthetic pigments, proline, RWC%, CAT and POX enzyme activities as well as leaf anatomy. This study highlights the potential ameliorative effects of SA or EBL in mitigating the phytotoxicity of NaCl stress in seeds and growing seedlings. © 2013 South African Association of Botanists.

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