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Materials Sciences and Applications 2014年第13期5卷 932-942页

作者： mohamed Ali Ahmed Kasim el-Sayed Rady kamel mohamed el-shokrofy Ahmed Abo Arais mohamed Said Shams Materials Science Laboratory Physics Department Faculty of Science Cairo University Giza Egypt Engineering Basic Sciences Department Faculty of Engineering Menoufia University Shebin El-Kom Egypt Department of Physics and Engineering Mathematics Faculty of Electronic Engineering Menoufia University Al Minufya Egypt

The effect of Zn2+ ions on the microstructure and electrical properties of Mn1-xZnxFe2O4 (0.0 ≤ x ≤ 0.5 in steps of 0.1) through a solid state reaction has been investigated. The structural properties have been investigated using X-ray diffraction (XRD) technique. The XRD analysis confirms that all samples are in a single-phase cubic spinel structure. The experimental lattice parameter (aexp) was decreased with increasing Zn2+ ions substitution due to the smaller ionic radius of zinc content. The crystallite size (t) of samples was estimated by Scherrer’s formula and found in the range (90 - 115 nm). Dc electrical resistivity and Seebeck voltage coefficients were measured as a function of temperature using the two probe methods. The temperature variation of resistivity exhibits two breaks, each break referring to a change in the activation energy. The Curie temperature estimated from dc resistivity measurement decreases with increasing Zn2+ ions. Seebeck voltage coefficient measurements reveal n-type conduction for all samples.

关键词： Mn-Zn Ferrite XRD Microstructure IR DC Resistivity Seeback Coefficient

Wood By-Products as UV Protection:A Consequence Review

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Journal of Renewable Materials 2024年第4期12卷 699-720页

作者： Naglaa Salem el‑Sayed mohamed Hasanin Samir kamel Cellulose and Paper Department National Research CentreCairo12622Egypt

In recent decades,the ozone layer has suffered considerable damage,increasing the entry of ultraviolet(UV)light into the atmosphere and reaching the earth’s surface,negatively affecting ***,researchers aimed to solve this problem by synthesizing advanced UV-shielding *** the other hand,developing an easy and green strategy to prepare functional materials with outstanding properties based on naturally abundant and environmentally friendly raw materials is highly desirable for sustainable *** biomass-derived materials are sustainable and biodegradable,they present a promising substitute for petroleum-based *** three main structural constituents of the plant biomass-based materials that are naturally available are cellulose,hemicellulose,and *** review details current developments using wood-based products such as cellulose,hemicellulose,and lignin in UV-shielding *** will start with assembling the structure and chemistry of cellulose,hemicellulose,and lignin,followed by their contributions to preparing UV-shielding ***,it will briefly discuss the different processing methods for the design of UV-shielding *** wood by-products offer additional opportunities to use the whole tree harvest.

关键词： UV-shielding wood cellulose lignin hemicellulose sunlight protection

Innovative surfactant of Gemini-type for dissolution mitigation of steel in pickling HCl medium

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Chinese Journal of Chemical Engineering 2021年第6期34卷 125-133页

作者： Medhat kamel mohamed Hegazy Salah Rashwan mohamed el Kotb Department of Chemistry Faculty of ScienceSuez Canal UniversityIsmailia 41522Egypt Egyptian Petroleum Research Institute(EPRI) Nasr CityCairo 11727Egypt

A new surfactant of Gemini-type,N,N'-((phthylbis(oxy))bis(ethane-2,1-diyl))bis(N,N-dimethyldodecan-1-aminium bromide)is prepped&*** dissolution suppression impact of the new compound on steel is performed in 1 mol·L^(-1)HCl environment by means of chemical and electrochemical *** prepared surfactant is an agreeable dissolution inhibitor for *** mitigation efficacy rises with the quantity of the *** surfactant belongs to inhibitors of *** adsorption of the synthesized compound followed the Langmuir's *** negative magnitudes of bothΔG_(ads)^(θ) andΔH^(adsθ)indicate that the adsorption process proceeds from its own accord and *** mechanism of adsorption is elucidated by scanning *** is established that the transfer resistance(R_(ct))value rose,where the value of the phase element(CPE)reduced with the amount of synthesized *** to the experimental data arrived by surface tension measurements,the prepared compound is a powerful active agent at the air/water boundary.

关键词： Innovative Gemini surfactant Synthesis Dissolution mitigation Steel Pickling HCl media

Development of Magnetite/Graphene Oxide Hydrogels from Agricultural Wastes for Water Treatment

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Journal of Renewable Materials 2022年第7期10卷 1889-1909页

作者： Hebat-Allah STohamy mohamed el-Sakhawy Samir kamel Cellulose and Paper Department National Research CentreCairo12622Egypt

A novel magnetic hydrogel loaded with graphene oxide(GO)was developed in this ***,GO was prepared from bagasse through a single step via oxidation in the presence of ferrocene under muffled atmospheric conditions,followed by the loading of different amounts of magnetite onto GO via co-precipitation reaction of iron onto GO ***,the 2-acrylamido-2-methyl-1-propane sulfonic acid was grafted onto carboxymethyl cellulose in the presence of magnetite GO and N,N′-methylenebisacrylamide as crosslinker yielded *** structure,morphological,and thermal behavior of the prepared hydrogels were *** addition,the adsorption performance of Ni(Ⅱ)ions from aqueous media by the prepared hydrogels was investigated as a function of temperature,time,and concentration of adsorbate in a batch *** results demonstrated a remarkable enhancement in the adsorption process of Ni(Ⅱ)(Removal efficiency=98.82%).All isotherms were found to fit the Langmuir model *** adsorption properties of both magnetic GO and magnetic hydrogel showed promising properties as green and cheap adsorbents.

关键词： Magnetite graphene oxide hydrogel Ni(Ⅱ)adsorption kinetic models thermodynamics

Experimental investigation and comparative study of interturn short-circuits and unbalanced voltage supply in induction machines

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Frontiers in Energy 2013年第3期7卷 271-278页

作者： Fatima BABAA Abdelmalek KHEZZAR mohamed el kamel OUMAAMAR Department of electrical Engineering Mentouri University Constantine25000 Algeria

A transient model for an induction machine with stator winding turn faults on a single phase is derived using reference frame transformation theory. The negative sequence component and the 3rd harmonic are often considered as accurate indicators. However, small unbalance in the supply voltage and/or in the machine structure that exists in any real system engenders the same harmonics components. In this case, it is too difficult to distinguish between the current harmonics due to the supply voltage and those originated by inter-turn short- circuit faults. For that, to have the correct diagnosis and to increase the sensitivity and the reliability of the diagnostic system, it is crucial to provide the relationship between the inter-turn short-circuits in the stator winding and the supply voltage imbalance through an accurate mathematical model and via a series of experimental essays.

关键词： induction machines fault indicator inter-turn short-circuit fault unbalance supply voltage

Bitter gourd extract improves glucose homeostasis and lipid profile via enhancing insulin signaling in the liver and skeletal muscles of diabetic rats

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Asian Pacific Journal of Tropical Biomedicine 2021年第8期11卷 344-352页

作者： Saber mohamed Eweda Mennatallah Ahmed Ali Hala mohamed Abd el-Bary Nahed Hussein el-Sokkary Madiha Hassan Helmy Maher Abdel-Nabi kamel Department of Biochemistry Faculty of ScienceAlexandria UniversityAlexandriaEgypt Department of Pharmacology&Therapeutics Faculty of Pharmacy and Drug ManufacturingPharos University in AlexandriaAlexandriaEgypt Department of Biochemistry Medical Research InstituteAlexandria UniversityAlexandriaEgypt Department of Physiology Faculty of MedicineAlexandria UniversityAlexandriaEgypt Medical Laboratories Technology College of Applied Medical SciencesTaibah UniversityMadinahKSA

Objective:To investigate the modulatory effects of bitter gourd extract on the insulin signaling pathway in the liver and skeletal muscle tissues of diabetic ***:The ethanolic extract of bitter gourd was prepared and its contents of total polyphenols and flavonoids were assayed.A neonatal streptozotocin-induced diabetic rat model was established and the diabetic rats were assigned into different groups and were treated with different doses of bitter gourd extract(100,200,400,or 600 mg/kg)or with glibenclamide(0.1 mg/kg)for 30 *** blood glucose,insulin,and lipid profile were evaluated and the insulin signaling pathway in the liver and skeletal muscle of rats was *** correlations between homeostasis model assessment(HOMA)and the components of insulin signaling pathway were also ***:Different doses of bitter gourd extract significantly ameliorated fasting blood glucose level and HOMA index for insulin ***,bitter gourd extract increased serum insulin and improved disrupted serum lipid *** levels of insulin receptor substrate-1(IRS-1),p-insulin receptorβ(p-IR-β),protein kinase C(PKC),GLUT2,and GLUT4 were improved by treatment with bitter gourd *** best results were obtained with 400 mg/kg dose of the extract,the effect of which was equivalent to that of *** in the bitter gourd treated rats was negatively correlated with p-IR-β,IRS-1 and PKC in hepatic and skeletal *** was also negatively correlated with skeletal muscle ***:Bitter gourd extract improves glucose homeostasis and lipid profile in diabetic rats via enhancement of insulin secretion and ***,bitter gourd can be used as a potential pharmacological agent for the treatment of type 2 diabetes mellitus.

关键词： Neonatal Streptozotocin Diabetic Sulfonylurea Bitter gourd Phosphorylated insulin receptor Protein kinase C IRS-1 GLUT2/GLUT4 Insulin signaling

Hepatitis C Virus RNA Strands Detection in Peripheral Blood Mononuclear Cells Legitimizes Virus Eradication in Negative Serum PCR Naive and Post-treatment Patients

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Journal of Clinical and Translational Hepatology 2017年第1期5卷 1-8页

作者： mohamed Darwish Ahmed Abd Alla Mostafa kamel el Awady Tropical Medicine Department Faculty of MedicineAl-Azhar UniversityCairoEgypt Department of Microbial Biotechnology National Research CenterCairoEgypt

Background and Aims:Hepatitis C virus(HCV)hepatotropism is associated with intra-peripheral blood mononuclear cell(PBMC)infection that causes post-treatment relapse in RNA seronegative *** understanding of the association of non-viremic hepatic fibrosis with positive anti-HCV IgG antibodies and active hepatocellular damage might be increased by PBMCs screening for intracellular ***,the goals of this study included evaluation of PBMCs PCR for diagnosing HCV infection,addressing PBMCs plus serum real-time(SRT)PCR benefits over SRT-PCR alone,studying intraPBMCs distribution of RNA sense and antisense strands,and identifying treatment feasibility in solitary intracellular ***:Enzyme-linked immunosorbent assay,SRT-PCR and PBMCs PCR were used to evaluate HCV infection in 401 *** patients were classified into groups of negative controls(n=30),positive controls(n=63),non-viremia post-treatment(experienced;n=166)and na(i)ve(n=49)cases,and non-viremia positive PBMCs PCR na(i)ve(n=35)and experienced(n=58)***:The diagnosis of true positive and negative by PBMCs PCR and SRT-PCR had 100%and 96.7%compatibility *** PCR detected intracellular HCV infection in 49 out of 215 non-viremia patients;among them,na(i)ve cirrhotics had significantly higher number of intracellular infection than the na(i)ve non-cirrhotic(Pely recognized in na(i)ve and experienced cases(P=0.01218).Intracellular HCV strands were detected in 18.02%of experienced *** of intracellular RNA strands showed significant decline in experienced compared to na(i)ve patients(Pellular HCV when SRT-PCR is *** and sense strands are respectively recognized more often in na(i)ve and experienced *** expected overall relapsing rate in our cohort was 18.02%.Int

关键词： HCV PBMCs RNA Strands

Burden of pediatric influenza A virus infection post swine-flu H1N1pandemic in Egypt

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Asian Pacific Journal of Tropical Medicine 2013年第9期6卷 693-698页

作者： Adel Khattab Malak Shaheen Terez kamel Amel el Faramay Safaa Abd el Rahman Dalia Nabil mohamed Gouda Influenza Advisory Board Egyptian Ministry of Health Chest Department Faculty of MedicineAin Shams University Pediatrics Department Faculty of MedicineAin Shams University Medical Microbiology and Immunology Department Faculty of MedicineAin Shams University

Objectne:To screen children with influenza like illness or with symptoms of acute respiratory tract infections for influenza A virus infection-post swine flu pandemic era-using rapid influenza diagnostic ***:During two year,(2010&2011),1200 children with influenza like illness or acute respiratory tract infections(according to World Health Organization criteria)were *** ages ranged from 2-60 *** aspirates specimens were collected from all children for rapid influenza A diagnostic ***:Influenza A virus rapid test was positive in 47.5%of the children;the majority(89.6%)were presented with lower respiratory tract *** rate and temperature were significantly higher among positive rapid influenza test ***:Influenza A virus infection is still a major cause of respiratory tract infections in Egyptian *** should be considered in all cases with cough and febrile episodes and influenza like symptoms even post swine flu pandemic.

关键词： Influenza A virus Burden Children Influenza like illness Egypt

Assessment of seminal plasma laminin in fertile and infertile men

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Asian Journal of Andrology 2007年第1期9卷 63-67页

作者： mohamed R. el-Dakhly Gamil A. Tawadrous Taymour Mostafa mohamed M. F. Roaia Abdel R. M. el-Nashar Shedeed A. Shedeed Ihab I. kamel Amal A. Aziz Yasser el-Mohtaseb Andrology Department Faculty of Medicine Cairo University Cairo 12311 Egypt Medical Biochemistry Department Faculty of Medicine Cairo University Cairo 12311 Egypt Clinical Pathology Department Faculty of Medicine Cairo University Cairo 12311 Egypt

Aim： To assess laminin levels in the seminal plasma of infertile and fertile men, and to analyze the correlation of laminin levels with sperm count, age, sperm motility and semen volume. Methods： One hundred and twenty-five recruited men were equally divided into five groups according to their sperm concentration and clinical examination： fertile normozoospermia, oligoasthenozoospermia, non-obstructive azoospermia （NOA）, obstructive azoospermia （OA） and congenital bilateral absent vas deferens （CBAVD）. The patients＇ medical history was investigated and patients underwent clinical examination, conventional semen analysis and estimation of seminal plasma laminin by radioimmunoassay. Results： Seminal plasma laminin levels of successive groups were： 2.82 ± 0.62, 2.49 ± 0.44, 1.77 ± 0.56, 1.72 ± 0.76, 1.35 ± 0.63 U/mL, respectively. The fertile normozoospermic group showed the highest concentration compared to all infertile groups with significant differences compared to azoospermic groups （P 〈 0.05）. Testicular contribution was estimated to be approximately one-third of the seminal laminin. Seminal plasma laminin demonstrated significant correlation with sperm concentration （r = 0.460, P 〈 0.001） and nonsignificant correlation with age （r = 0.021, P = 0.940）, sperm motility percentage （r = 0.142, P = 0.615） and semen volume （r = 0.035, P = 0.087）. Conelusion： Seminal plasma laminin is derived mostly from prostatic and testicular portions and minimally from the seminal vesicle and vas deferens. Estimating seminal laminin alone is not conclusive in diagnosing different cases of male infertility.

关键词： male infertility semen seminal plasma testis basement membrane laminin azoospermia congenital bilateral absent vas deferens

Vegetation productivity responses to drought on tribal lands in the four corners region of the Southwest USA

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Frontiers of Earth Science 2018年第1期12卷 37-51页

作者： mohamed Abd Salam el-VILALY kamel DIDAN Stuart E. MARSH Willem J.D. VAN LEEUWEN Michael A. CRIMMINS Armando Barreto MUNOZ The Intemational Food Policy Research Institute Washington DC 20006-1002 USA Vegetation Index and Phenology Lab Department of Agricultural and Biosystems Engineering The University of Arizona Tucson AZ 85721-0036 USA Arizona Remote Sensing Center School of Natural Resources and the Environment The University of Arizona Tucson AZ 85721-0043 USA Department of Soils Water and Environmental Science The University of Arizona Tucson AZ 85721-0038 USA

For more than a decade, the Four Comers Region has faced extensive and persistent drought conditions that have impacted vegetation communities and local water resources while exacerbating soil erosion. These persistent droughts threaten ecosystem services, agriculture, and livestock activities, and expose the hypersensitivity of this region to inter-annual climate variability and change. Much of the intermountain Western United States has sparse climate and vegetation monitoring stations, making fine-scale drought assessments difficult. Remote sensing data offers the opportunity to assess the impacts of the recent droughts on vegetation productivity across these areas. Here, we propose a drought assessment approach that integrates climate and topographical data with remote sensing vegetation index time series. Multisensor Normalized Difference Vegetation Index （NDVI） time series data from 1989 to 2010 at 5.6 km were analyzed to characterize the vegetation productivity changes and responses to the ongoing drought. A multi-linear regression was applied to metrics of vegetation productivity derived from the NDVI time series to detect vegetation productivity, an ecosystem service proxy, and changes. The results show that around 60.13% of the study area is observing a general decline of greenness （p 〈 0.05）, while 3.87% show an unexpected green up, with the remaining areas showing no consistent change. Vegetation in the area show a significant positive correlation with elevation and precipitation gradients. These results, while, confirming the region＇s vegetation decline due to drought, shed further light on the future directions and challenges to the region＇s already stressed ecosystems. Whereas the results provide additional insights into this isolated and vulnerable region, the drought assessment approach used in this study may be adapted for application in other regions where surfacebased climate and vegetation monitoring record is spatially and temporally limited.

关键词： drought remote sensing Hopi Navajo Nation