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A comparative study of liquid and solid inner contact roxatidine acetate ion-selective electrode membranes

Chinese Chemical Letters 2015年第6期26卷 714-720页

作者： Mohamed K.Abd el-Rahman Hala E.Zaazaa Samah S.Abbas Badr el-Zeany Zeinab a.el-Sherif dalia a.el-haddad Analytical Chemistry Department Faculty of PharmacyCairo University National Organization for Drug Control and Research

A comparative study was conducted using two designs of a roxatidine acetate （ROX）-selective electrode; a conventional liquid inner contact called electrode A and a graphite-coated solid contact called electrode 13. The fabrication of electrodes was based on roxatidine-tetraphenylborate （ROX-TPB） as an ion-association complex in a PVC matrix using different plasticizers. electrode A has a linear dynamic range of 2.2 ×10^-5 mol/L to 1.0 ×10^-2 mol/L, with a Nernstian slope of 54.7 mV/decade and a detection limit of 1.4 ×10^-6 mol/L. electrode B shows linearity over the concentration range of 1.0×10^-6 mol/L to 1.0×10^-2 tool/L, with a Nernstian slope of 51.2 mV/decade and a limit of detection of 1.1×10^7 mol/L which is remarkably improved as a result of diminishing ion fluxes in this solid contact, ion-selective electrode. The proposed sensors display useful analytical characteristics for the determination of ROX in bulk powder and its pharmaceutical formulation. The present electrodes show clear discrimination of ROX from several inorganic, organic ions, sugars, some common drug excipients and the degradation product （3-[3-（1-piperidinyl methyl） phenoxy] propyl amine） of ROX. Furthermore, the proposed electrodes were utilized for the determination of ROX in human plasma, where electrode B covers drug Cmax which indicated its applicability to pharmacokinetic, bioavailability and bioequivalent studies. The results obtained by the proposed electrodes were statistically analyzed and compared with those obtained by a reported HPLC method. No significant difference for either accuracy or precision was observed.

关键词： Comparative study Roxatidine acetate Liquid inner contact electrode Solid contact electrode Degradation product Plasma

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Thermal explosion of a reactive gas mixture at constant pressure for non-uniform and uniform temperature systems

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Defence Technology（防务技术） 2022年第10期18卷 1842-1851页

作者： Saad a.el-Sayed Mechanical Power Engineering Dept.Zagazig University ZagazigAlshrkiaEgypt

In this study,the approximate and exact solutions for the stationary-state of the solids model with neglecting reactant consumption for both non-uniform and uniform temperature systems were applied on gas ignition under a constant pressure *** criticality conditions for a slab,an infinite cylinder,and a sphere are determined and discussed using dimensionless temperatures under constant ambient and surface temperatures for a non-uniform temperature *** solution for a Semenov model with convection heat loss was also *** solution of the Semenov problem for constant volume or density as a solid and constant pressure were *** critical parameterδis calculated and compared with those of Frank-Kamenetskii solution *** validation of the calculated ignition temperatures with other exact solution and experimental results were *** relation between critical parameters form Semenov and *** solution was introduced.

关键词： Thermal explosion Approximate solution Critical conditions Distributed and uniform temperature systems

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Ca-,Al-rich refractory inclusions and Pt-metal nuggets in the Ningqiang carbonaceous chondrite

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Chinese Science Bulletin 1999年第8期44卷 725-731页

作者： a.el Goresy Max-Planck-Institut fr Kernphysik 6 900 Heidelberg 1 Germany

Petrography and mineral chemistry of Ca, Al-rich inclusions of Ningqiang carbonaceous chondrite are studied and the highly Re-Os fractionated Pt-metal nuggets in it is discovered. The refractory inclusions are classified into melilite-spinel-rich, and spinel-pyroxene-rich types. The former probably crystallized from melts, while the latter could be aggregates of the nebular condensates. The strong f ractionation between Re and Os suggests a pre-solar origin of the Pt-metal nuggets, which probably experienced various processes of formation and evolution before being captured by the refractory inclusions as indicated by the depletions of W and Mo.

关键词： meteorite refractory inclusion Pt-metal nuggets solar nebula.

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Modeling environmental sensitivity and risk assessment of PAHs in sediments along two marine coastal areas in Egypt

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Petroleum Research 2024年第1期9卷 125-142页

作者： Muhammad a.el-Alfy National Institute of Oceanography and Fisheries NIOFCairoEgypt

Modeling the environmental sensitivity index(ESI)is vital in the planning and management processes,especially along the coastal *** main objectives of the study were to define the main sources of polycyclic aromatic hydrocarbons(PAHs),establish an ESI model,and measure the risk of PAHs on humans and the environment using various *** methodology of the research involved analyzing PAHs according to the EPA 550 methodology in sediments of the coastline in two important coastline areas in Egypt,na.ely the Gulf of Suez and the Mediterranean Sea,modeling the sensitivity of PAHs using ArcGIS 10.5 by integrating different physical,biological,and land use/cover factors,identifying the sources,and performing a risk *** sediment samples were collected from each *** produced sensitivity map could explain the highly sensitive areas along the Mediterranean Sea and Gulf of Suez coastlines(especially areas that were near drains'outlets,industrial sites,and sea ports).The highest mean PAH concentrations were Acenaphthylene and Fluorine in the Mediterranean Sea and Suez Gulf,***'s obvious that the individual PAH concentrations were within the ERL,ERM,and Pel threshold limits,indicating no adverse biological *** ratios of BaA/BaA+Chy,Flu/Flu+Py,and Ant/Ant+Phe gave an indication that most PAH sources were petrogenic(63.64%)and others(36.36%)were from petroleum *** principle component analysis(PCA)indicated a diverse correlation among the isomer ratios and LU/LC *** carcinogenic risk values were in the very low category(elines and seawater free of oil spillage act

关键词： Polycyclic aromatic hydrocarbons(PAHs) Modeling Sensitivity Gulf of Suez And Mediterranean sea

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Enhancing optical absorption in visible light of ZnO co-doped with europium and promethium by first-principles study through modified Becke and Johnson potential scheme

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Journal of Rare Earths 2019年第4期37卷 416-421页

作者： A.G.el Hachimi M.L.Ould NE a.el Yousfi A.Benyoussef a.el Kenz Laboratory of Condensed Matter and Interdisciplinary Sciences (LaMCScI) Associé Au CNRST (URAC 12) Département de Physique B.P.1014 Faculté des SciencesUniversité Mohammed V Hassan Ⅱ Academy of Science and Technology

By using first-principles calculations we studied the electronic, optical and magnetic properties of ZnO co-doped with Eu and Pm. In this calculation, we used Wien2 k code based on full potential linearized augmented plane waves(FP-LAPW) method with the modified Becke-Johnson(mBJ) approximation. This correction gives good band gap compared to experimental band gap. The introduction of Eu and Pm codoping leads to an increase in the band gap. electrons can transit easily from the valence band to the conduction band, which results in an enhancement of visible light absorption in a wider absorption range. Absorption spectra reach a high value in visible and infrared light regions. With the significance of the obtained results, the studied compounds may potentially find spintronic and optoelectronic applications.

关键词： Zinc oxide Rare earth Density functional theory Modified Becke-Johnson Magnetic properties Spintronics

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Ginseng a.eliorates pulmonary toxicity induced by silicon dioxide nanoparticles in rats

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Asian Pacific Journal of Tropical Biomedicine 2021年第6期11卷 254-262页

作者： Raghda a.el-Sayed Fatma M.el-Demerdash Mohammed a.el-Magd Department of Environmental Studies Institute of Graduate Studies and ResearchAlexandria UniversityEgypt Department of Anatomy Faculty of Veterinary MedicineKafrelsheikh UniversityEgypt

Objective:To investigate the protective and therapeutic role of ginseng against silicon dioxide nanoparticles(SiO2NPs)-induced toxicity in the ***:Sixty male rats were divided into five groups(n=12/group);group 1 was used as a control,group 2 received ginseng,group 3 was treated with SiO2NPs,and group 4 was pretreated with ginseng one week before SiO2NPs,while group 5 was given SiO2NPs one week before supplementation with *** were treated with both ginseng and SiO2NPs orally for five ***-time PCR was used to measure gene ***,DNA damage and cell cycle changes were determined by comet assay and flow cytometry,*** study was also done to assess the effect of ginseng on SiO2NPs-induced ***:SiO2NPs increased lipid peroxidation and decreased the activities of antioxidant ***2NPs induced apoptosis in lung tissues as revealed by upregulation of Bax and caspase 3 and downregulation of Bcl-2 as well as the induction of DNA ***2NPs also caused inflammation as indicated by upregulation of the inflammation-related genes[interleukin 1 beta(IL-1β),tumor necrosis factor-alpha(TNF-α),nuclear factor kappa B(NF-κB),cyclooxygenase 2(COX2),and transforming growth factor-beta 1(TGFβ1)]as well as cell cycle arrest in the G0/G1 phase of lung ***,histopathological examination proved the biochemical and molecular perturbations that occurred due to SiO2NPs ***,ginseng alleviated SiO2NPs-induced toxicity in rat ***:Ginseng has a potent preventive and therapeutic effect and could be used in the treatment of SiO2NPs-induced pulmonary toxicity.

关键词： Silicon dioxide nanoparticles Ginseng Oxidative stress Inflammation Pulmonary toxicity

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Air renewal times and ventilation rate calculations for underground workings using radioactive measurement

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International Journal of Mining Science and Technology 2016年第5期26卷 843-850页

作者： Ayman a.el-Abnoudy Sayed F.Hassan Production Sector Nuclear Materials Authority

Potential alpha emitters are of prime concern to the ventilation engineer due to their rapid concentration increasing once radon released in the mine atmosphere, causing tissue irradiation and lung *** of the time based variations of the natural ventilation in tunnels and their relationship to the external parameters contribute to the air circulation assessment. Due to the continuous and high fluctuation of the meteorological conditions affecting the air circulation and intensity through the underground workings, there is a difficulty in the natural ventilation assessment by only the ordinary meteorological measurements. So, in this paper, the possibility of using the radioactive measurements, allowing for the air aging and ventilation quality to be qualified, is investigated through three different underground structures. Referring to the most confined structure of them, results show that one structure has a better exchange rate by a factor 1.8 and the other has the best rate by a factor 2.1. This parameter can be linked to the operating costs and size of a future ventilation system.

关键词： Mining ventilation Air circulation Radon gas measurement Air aging

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Synthesis, spectral, optical and anti-inflammatory activity of complexes derived from 2-aminobenzohydrazide with some rare earths

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Journal of Rare Earths 2015年第7期33卷 758-764页

作者： Nasser Mohammed Hosny el Sayed a.el Morsy Yousery E.Sherif Chemistry Department Faculty of Science Port-Said University Clinical Pharmacology Department Faculty of Medicine Mansoura University Pharmacology and Therapeutics Department Qassim College of Medicine Qassim University Department of Chemistry Faculty of Science and Arts Taibah University

Three new metal complexes derived from Er（Ⅲ）, Dy（Ⅲ） and Zr（Ⅳ） with 2-aminobenzohydrazide （ABH） were synthesized and characterized by elemental analyses, IR, ^1H-NMR, ES-MS and transmission electron microscopy （TEM）. The morphology and the particle size were determined by TEM. The results showed that the ligand acted as neutral bi-dentate coordinating to the metal ions through the carbonyl oxygen and amidic amino nitrogen. The aromatic amine group remained inert towards coordination. The optical band gap was measured and found to be 3.3, 3.5 and 4.3 eV for Er（Ⅲ）, Dy（Ⅲ） and Zr（Ⅳ）, respectively. The optical band gap values indicated a semi-conducting nature of the investigated complexes. The anti-inflammatory and analgesic activities of the tested compounds were determined and compared with standard meloxicam.

关键词： Er(Ⅲ) Dy(Ⅲ) Zr(Ⅳ) metal complexes optical band gap rare earths

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Dynamics of a multi-mode maximum entangled coherent state over an amplitude damping channel

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Chinese Physics B 2011年第11期20卷 67-73页

作者： a.el Allati Y.Hassouni N.Metwally Faculté des Sciences Laboratoire de Physique Theorique URAC 13Université Mohammed V-Agdal The Abdus Salam International Centre for Theoretical Physics Mathematics Department College of ScienceUniversity of Bahrain Mathematics Department Faculty of ScienceSouth Valley University

The dynamics of the maximum entangled coherent state tra.eling through an amplitude damping channel is investigated. For small values of the transmissivity rate, the tra.eling state is very fragile to this noise channel, which suffers from the phase flip error with high probability. The entanglement decays smoothly for larger values of the transmissivity rate and speedily for smaller values of this rate. As the number of modes increases, the tra.eling state over this noise channel quickly loses its entanglement. The odd and even states vanish at the same value of field intensity.

关键词： entanglement quantum communication decoherence coherent states

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Implementing Effective Learning with Ubiquitous Learning Technology During Coronavirus Pandemic

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Computer Systems Science & Engineering 2022年第1期40卷 389-404页

作者： Hosam F.el-Sofany Samir a.el-Seoud King Khalid University AbhaKingdom of Saudi Arabia Cairo Higher Institute for Engineering Computer Science and ManagementCairoEgypt British University in Egypt—BUE Faculty of Informatics and Computer ScienceCairoEgypt

Ubiquitous computing supports U-learning to develop and implement a new educational environment that provides effective and interactive learning to students wherever they *** study aims to present a qualitative evaluation for using U-learning instead of traditional education to avoid the spread of the Coronavirus *** authors introduce a UTAUT(Unified Theory of Acceptance and Use of Technology)model to assess the capability of the given factors that are expected to affect the learners’intention and behavior for accepting the U-learning technology for full *** research study shows a promising impact on the use of U-learning apps for implementing their learning activities in both the present and coming *** study also presents the descriptive statistics that affect the students’answers by using U-learning while implementing learning assignments including exams,projects,forums,essays,presentations,and *** research experiments demonstrate both the composite reliability(CR)and the average variance extracted(AVE)of the presented *** experimental results have shown that(1)the factor loadings≥0.75,CR≥0.9,and AVE≥0.75,which present appropriate proof for the validity and reliability of the proposed model,and(2)the total average of students that accept the U-learning is 82.99%,and who disagree is 8.13%,while who neither agree nor disagree is 6.44%.

关键词： Ubiquitous learning U-learning E-learning M-learning COVID-19 pandemic coronavirus UTAUT model

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