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Influence of Zn^(2+)or Cu^(2+) on Reduction and Recalcination Behavior of Fe_2TiO_5

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Journal of materials Science & Technology 2007年第5期23卷 697-702页

作者： m.bahgat m.H.Khedr H.S.Abdelmaksoud CmRDI P.O.Box 87-HelwanCairoEgypt Chemistry Department Faculty of ScienceBenisuef UniversityEgypt

Fe2O3, TiO2, CuO and ZnO powders were mixed according to the formula of （1-x）TiO2 xCuO-Fe2O3 or （1-x）TiO2 xZnO-Fe2O3 （x=0, 0.2 0.4, 0.6, 0.8, 1）, and well ball-milled with H2O for 3 h to ensure homogeneity of the powdered solids, then fired at 1200℃ for 4 h. The fired samples were reduced at 500℃ with hydrogen gas. The reduced samples were subjected to recalcination at 500℃ in CO2 atmosphere. Both of fired, reduced and calcined samples were characterized by X-ray diffraction, vibrating sample magnetometry, reflected light microscopy and scanning electron microscopy. Different phases were formed after firing of Cu^＋2 or Zn^2＋ substituted Fe2TiO5. magnetization （Bs） of the formed phases after firing are very low corresponding to diluted magnetic semiconductors （DmS） and increases with increasing the substituted cations （Cu^＋2 or Zn^2＋）. The reduction of the fired samples enhanced the Bs values whereas the reducibility increases with increasing the Cu^＋2 or Zn^2＋ content. Samples show different tendency toward CO2 decomposition which is very important for environmental minimization for CO2.

关键词： nanosized ferrite Titanate Reduction magnetic properties Reduction-recalcin-ation CO2 decomposition

Formation of Aln from Secondary Al Resources

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Journal of materials Science & Technology 2006年第5期22卷 621-624页

作者： m.bahgat m.Radwan F.E.Farghaly Central metallurgical Research and Development Institute (CmRDI) P.O.Box 87 Helwan Cairo 11421 Egypt

Synthesis of Aln by nH4Cl-assisted direct nitridation of secondary Al resources was studied. Aluminum alloy scrap contained mg and Zn element was used. milled Al scrap （-1 mm） was mixed with nH4Cl and heated at 1000℃ for 1 h in presence of 1 L/min n2 flow gas. The nitrided product was evaluated by X-ray diffraction semi-quantitative analysis and scanning electron microscopy （SEm）. Aluminium nitride of 90.5% concentration was obtained with a hexagonal crystalline form. Aln is mostly formed in nano-whisker morphology （50～150 nm） which is homogenously distributed.

关键词： Aln Direct nitridation nanowhisker Secondary resources

Enhancement of Electric Conductivity in Transparent Glasse—Ceramic nanocomposites of Bi_2O_3—BaTiO_3 Glasses

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Journal of materials Science & Technology 2013年第12期29卷 1166-1176页

作者： A.A.bahgat m.G.moustafa E.E.Shaisha Department of Physics Faculty of ScienceAl-Azhar University

The frequency and temperature dependent electrical conductivity measurements for heat-treated binary glass system with composition of （lO0-x）Bi203-xBaTi03 （x = 20, 30, 40 and 50, in mol%） were carried out. The glass was prepared by melt quenching technique and their corresponding glass-ceramic nanocomposites were obtained by suitable heat treatment. nanostructured behavior and electrical properties of these glasses and their corresponding glass-ceramic nanocomposites were studied. X-ray diffraction （XRD） and differential scanning calorimetry confirmed the amorphous nature of the glasses. moreover, XRD patterns of the samples indicate nanocrystallites embedded in the glass matrix. The Fourier transform infrared spectroscopy （FT-IR） spectral analysis showed that the band positions of glass system are within the wave number range of Bi06, Bi03 and Ti06 structural units. It is observed that the electrical conductivity is enhanced by 102-103 times in the transparent glass-ceramic nanocomposite phase. With further heat treatment, the conductivity decreased considerably in the stage of glass-ceramic nanocomposite phase as compared with the glassy phase sample. Therefore, partially devitrified phase is more suitable as cathode material in secondary batteries compared to its vitreous or fully crystalline counterpart. The conduction mechanism was confirmed to obey the adiabatic small polaron hopping （SPH）. AC conductivity measurements were performed as a function of temperature and frequency, showing a very slow increasing rate at low temperatures and then a fast rate at higher temperatures.

关键词： Barium titanat Transparent glass--ceramic nanocomposites DC electrical conductivity AC electrical conductivity Smallpolaron hopping

Interaction Between the neglected Tropical Disease Human Schistosomiasis and HCV Infection in Egypt:a Puzzling Relationship

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Journal of Clinical and Translational Hepatology 2014年第2期2卷 134-141页

作者： mahmoud m. bahgat Immunology and Infectious Diseases Group Therapeutic Chemistry Department the Centre of Excellence for Advanced Sciences the National Research Centre Dokki Cairo Egypt Research Group of Biomarkers for Infection and Immunity Institute of Experimental Infection Research TWINCORE Centre for Experimental and Clinical Infection Research Hannover Germany

Egypt has the highest prevalence of chronic hepatitis C virus (HCV) infection and seropositivity worldwide, and it has been proposed that this enhanced susceptibility to HCV is related to coinfection with schistosomiasis. Although currently, there are no studies regarding the actual prevalence of both human schistosomiasis and schistosomiasis/HCV coinfection evi-dences strongly support that eliminating human schistoso-miasis from Egypt is necessary to reduce both HCV prevalence and liver pathology. The present review highlights the significant impact of the neglected tropical disease human schistosomiasis on both susceptibility of Egyptians to HCV coinfection, severity of the resulting liver pathology, and poor response to antiviral therapy. The immune evasion mechan-isms exerted by the HCV-nS3/4A protease domain, and the possible impact of immune evasion mechanisms exerted by proteases of larval, worm and egg stages of the parasite Schistosoma on human susceptibility to HCV infection are discussed. In addition, schistosome immune evasion mechanisms may include immunosuppression that in turn prevents clearance of HCV viremia and leads to relapsing HCV infection and severe liver pathology. I propose the generation of a replicon system from the most prevailing genotype (HCV-4a) in Egypt and establishing its replication on hepatoplas-toma or immune cells in presence of bilharzial antigens. Finally, the use of a humanized small animal model that can acquire both HCV and S. mansoni infections will be important to further understand in real time the impact of coinfection on both the immune system and liver pathology.

关键词： Egypt neglected tropical disease Human schistosomiasis HCV Coinfection Immune evasion mechanisms HCV protease Schistosome pro-teases

HepG2 cells support viral replication and gene expression of hepatitis C virus genotype 4 in vitro

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World Journal of Gastroenterology 2006年第30期12卷 4836-4842页

作者： mostafa K El-Awady Ashraf A Tabll Yasmine S El-Abd mahmoud m bahgat.husse.n a shoe. Samar S Youssef noha G Bader El Din El-Rashdy m Redwan maha El-Demellawy moataza H Omran Wael T El-Garf Said A Goueli Department of Biomedical Technology National Research Center Tahrir Street PO 12622 Dokki Cairo Egypt Department of medicinal Chemistry Na- tional Research Center Tahrir Street PO 12622 Dokki Cairo Egypt Department of microbiology and Immunology Faculty of Pharmacy Cairo University Cairo Egypt Genetic Engineering and Biotechnology Research Institute New Borg El-Arab City Alexandria Egypt Department of Pathology School of medicine University of Wisconsin Madison WI United States

AIm： TO establish a cell culture system with longterm replication of hepatitis C virus （HCV） genome and expression of viral antigens in vitro. mETHODS： HepG2 cell line was tested for its susceptibility to HCV by incubation with a serum from a patient with chronic hepatitis C. Cells and supernatant were harvested at various time points during the culture. Culture supernatant was tested for its ability to infect na＇ive cells. The presence of minus （antisense） RnA strand, and the detection of core and E1 antigens in cells were examined by RT-PCR and immunological techniques （flow cytometry and Western blot） respectively. RESULTS： The intracellular HCV RnA was first detected on d 3 after infection and then could be consistently detected in both cells and supernatant over a period of at least three months. The fresh cells could be infected with supernatant from cultured infected cells. Flow cytometric analysis showed surface and intracellular HCV antigen expression using in house made polyclonal antibodies （anti-core, and anti-E1）. Western blot analysis showed the expression of a cluster of immunogenic peptides at molecular weights extended between 31 and 45 kDa in an one month old culture of infected cells whereas this cluster was undetectable in uninfected HepG2 cells. COnCLUSIOn： HepG2 cell line is not only susceptible to HCV infection but also supports its replication in vitro. Expression of HCV structural proteins can be detected in infected HepG2 cells. These cells are also capable of shedding viral particles into culture media which in turn become infectious to uninfected cells.

关键词： Hepatitis C virus In vitro propagation Genomic replication Gene expression HepG2 cells

Resveratrol and fenofibrate ameliorate fructose-induced nonalcoholic steatohepatitis by modulation of genes expression

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World Journal of Gastroenterology 2016年第10期22卷 2931-2948页

作者： Enas A Abd El-Haleim Ashraf K bahgat Samira Saleh Department of Pharmacology and Toxicology Faculty of PharmacyCairo University Currently Faculty of Pharmaceutical Sciences and Pharmaceutical Industries Future University in Egypt

AIm: To evaluate the effect of resveratrol, alone and in combination with fenofibrate, on fructose-induced metabolic genes abnormalities in ***: Giving a fructose-enriched diet (FED) to rats for 12 wk was used as a model for inducing hepatic dyslipidemia and insulin resistance. Adult male albino rats (150-200 g) were divided into a control group and a FED group which was subdivided into 4 groups, a control FED, fenofibrate (FEnO) (100 mg/kg), resveratrol (RES) (70 mg/kg) and combined treatment (FEnO + RES) (half the doses). All treatments were given orally from the 9th week till the end of experimental period. Body weight, oral glucose tolerance test (OGTT), liver index, glucose, insulin, insulin resistance (HOmA), serum and liver triglycerides (TGs), oxidative stress (liver mDA, GSH and SOD), serum AST, ALT, AST/ALT ratio and tumor necrosis factor-α (TnF-α) were measured. Additionally, hepatic gene expression of suppressor of cytokine signaling-3 (SOCS-3), sterol regulatory element binding protein-1c (SREBP-1c), fatty acid synthase (FAS), malonyl CoA decarboxylase (mCD), transforming growth factor-β1 (TGF-β1) and adipose tissue genes expression of leptin and adiponectin were investigated. Liver sections were taken for histopathological examination and steatosis area were ***: Rats fed FED showed damaged liver, impairment of glucose tolerance, insulin resistance, oxidative stress and dyslipidemia. As for gene expression, there was a change in favor of dyslipidemia and nonalcoholic steatohepatitis (nASH) development. All treatment regimens showed some benefit in reversing the described deviations. Fructose caused deterioration in hepatic gene expression of SOCS-3, SREBP-1c, FAS, mDA and TGF-β1 and in adipose tissue gene expression of leptin and adiponectin. Fructose showed also an increase in body weight, insulin resistance (OGTT, HOmA), serum and liver TGs, hepatic mDA, serum AST, AST/ALT rat

关键词： Fructose nonalcoholic steatohepatitis Suppressor of cytokine signaling-3 Sterol regulatory element binding protein-1c Fatty acid synthase malonyl CoA decarboxylase Leptin Adiponectin Transforming growth factor-β Tumor necrosis factor-α

Electrical Relaxation in mixed Alkali Bi_2O_3-K_2O-Li_2O-Fe_2O_3 Glasses

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Journal of materials Science & Technology 2006年第5期22卷 701-707页

作者： E.E.Shaisha Sh.F.El-Desouki I.Shaltout A.A.bahgat Department of physics Faculty of science Al-Azhar UniversityNasr CityCairo 11884Egypt

A new glass system （Bi2O3）50（Fe2O3）10（Li2O）x（K2O）40-x, where x changes in steps of 5 mole fraction between 0 and 40, was selected to study the electrical relaxation and the mixed alkali effect （mAE） phenomena. measurements of ac conductivity σac, dielectric permittivity ε′ and loss factor tanδ in the frequency range of 0.12～10^2 kHz and in the temperature range of 300～650 K were carried out. The temperature dependence of the ac conductivity shows a slow increasing rate at low temperature and high frequency and a rapid increase at high temperature and low frequency. At constant temperature, the ac conductivity is found to be proportional to ω^8, where s is the frequency exponent, which is less than 1. Analysis of the conductivity data and the frequency exponent shows that the overlapping large polaron tunnelling （OLPT） model of ions is the most favorable mechanism for the ac conduction in the present glass system. The ac response, the dc conductivity and dielectric relaxation have the same activation energy and they originate from the same basic transport mechanism. The results of the dielectric permittivity show no maximum peak in the temperature and frequency range studied. This absence of maximum peak is an indication of non-ferroelectric behavior of all the studied samples. The mAE has been detected in the ac conductivity, which is the same as the classical mAE in the dc conductivity. The electrical parameters such as dielectric permittivity ε′ and real dielectric modulus m′ show a typical minimum deviation from linearity by about two orders of magnitude. The loss factor tanδ and the imaginary dielectric modulus m″ are insignificantly dependent on composition even at the same transition temperature Tg.

关键词： Dielectric permittivity Dielectric modulus Loss factor Conduction mechanism mAE (mixed alkali effect)

Investigation of SARS-CoV-2 main Protease Potential Inhibitory Activities of Some natural Antiviral Compounds Via molecular Docking and Dynamics Approaches

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Phyton-International Journal of Experimental Botany 2022年第5期91卷 1089-1104页

作者： nada m.mostafa muhammad I.Ismail Amr m.El-Araby Dina m.bahgat Ahmed m.Elissawy Ahmed m.mostafa Omayma A.Eldahshan Abdel nasser B.Singab Department of Pharmacognosy Faculty of PharmacyAin Shams UniversityCairo11566Egypt Department of Pharmaceutical Chemistry Faculty of PharmacyThe British University in EgyptCairo11837Egypt Department of Pharmaceutical Chemistry Faculty of PharmacyAin Shams UniversityCairo11566Egypt Department of Biochemistry Faculty of PharmacyAin Shams UniversityCairo11566Egypt Center for Drug Discovery and Development Research Ain Shams UniversityCairo11566Egypt

Coronaviruses caused an outbreak pandemic disease characterized by a severe acute respiratory distress syndrome leading to the infection of more than 200 million patients and the death of more than 4 million *** primary treatment is either supportive or *** products have an important role in the development of various ***,screening of natural compounds with reported antiviral activities can lead to the discovery of potential inhibitory entities against *** the current study,an in-silico molecular docking experiment was conducted on the effects of some of these natural antiviral phytoconstituents,(e.g.,procyanidin B2,theaflavin,quercetin,ellagic acid,caffeoylquinic acid derivatives,berginin,eudesm-1β,6α,11-triol and arbutin),on the crystal structure of SARS-CoV-2 main protease(PDB ID:6w63)using AutoDock-Vina *** of the docked compounds revealed good binding affinity,with procyanidin B2(–8.6 Kcal/mol)and theaflavin(–8.5 Kcal/mol)showing a better or similar binding score as the ligand(–8.5 Kcal/mol).molecular dynamics simulations were carried out at 100 ns and revealed that procyanidin B2 forms a more stable complex with SARS-CoV-2 main protease than *** B2,theaflavin,and 4,5-dicaffeoylquinic acid were evaluated for toxicity by ProTox-II webserver and were non-toxic according to the predicted LD50 values and safe on different organs and ***,these phytoconstituents showed good ADmE properties and acceptable lipophilicity,as evaluated using *** the tested compounds,procyanidin B2 showed the highest lipophilic *** is worth mentioning that these natural inhibitiors of SARS-CoV-2 main protease are components of green and black tea that can be used as a supporting supplement for COVID patients or as potential nuclei for further drug design and development campaigns.

关键词： Coronavirus natural products SARS-CoV-2 main protease molecular docking molecular dynamics tea

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轴承间隙对齿轮动力响应的影响

机械传动 1983年第3期 22-26页

作者： m.O.m. OSman B.m. bahgat T.S.Sankar 张信志

本文提出了考虑轴承间隙的齿轮动力分析方法。本方法基于运动学与动力学的相互依存关系上,在轴承与轴颈相互接触时,此种依存关系是起主导作用的。接触模型被简化为轴承偏心矢量与接触点的轴承法向力必须在同一条直线上。分析本身主要依... 详细信息

本文提出了考虑轴承间隙的齿轮动力分析方法。本方法基于运动学与动力学的相互依存关系上,在轴承与轴颈相互接触时,此种依存关系是起主导作用的。接触模型被简化为轴承偏心矢量与接触点的轴承法向力必须在同一条直线上。分析本身主要依靠确定瞬时间隙角(轴承偏心矢量角)。间隙角控制方程用接触点位置的几何约束及速比导出。为说明此方法,分析了一个具有两个轴承旋转间隙(revolute clearanee)的刚性直齿轮作为例子。

关键词：齿轮轴承间隙间隙角动力响应动力反应