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Exploration of structural,optical,and photoluminescent properties of (1-x)NiCo_(2)O_(4)/xPbS nanocomposites for optoelectronic applications

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Chinese Physics B 2022年第6期31卷 663-670页

作者： Zein K Heiba mohamed bakr mohamed Noura M Farag Ali Badawi Physics Department Faculty of ScienceAin Shams UniversityCairoEgypt Physics Department Faculty of ScienceTaibah UniversityAl-Madina al MunawarahSaudi Arabia Department of Physics College of ScienceTaif UniversityP.O.Box 11099Taif 21944Saudi Arabia Department of Physics University College of TurabahTaif UniversityP.O.Box 11099Taif 21944Saudi Arabia

The(1-x)NiCo_(2)O_(4)/x PbS(0≤x≤0.2)nanocomposite samples are synthesized using the hydrothermal and thermolysis *** different phases developed in the obtained nanocomposite samples are accurately determined using the x-ray diffraction technique equipped with a *** percentage of the formed phases(NiCo_(2)O_(4)(NCO),PbS,PbSO_(4)),structural and microstructure parameters are determined using Rietveld quantitative phase *** transmission electron microscope(TEM)images and Rietveld analysis reveal almost isotropic particle size in the nano range with a very narrow size *** obtained phase percentage of PbS and PbSO4are smaller than nominated values(x)suggesting dissolving of some Pb and S ions into NCO which is then confirmed by the analysis of Fourier-transform infrared(FTIR)spectra of nanocomposite *** absorption spectra are modified upon doping NCO with *** optical band gaps of the nanocomposites increase as the amount of PbS *** effect of alloying on extinction coefficient,refractive index,dielectric constant,optical conductivity,the intensity,and emitted color from the photoluminescence of the nanocomposite samples are also *** refractive index value of NCO and NCO-PbS nanocomposite samples exhibit normal *** photoluminescent measurements reveal that the NCO-PbS nanocomposites can emit a violet *** improvement in the values of the nonlinear optical(NLO)parameters of pristine NCO at high frequencies or the nanocomposite samples at low frequencies,are made them used in NLO photonic devices.

关键词： Co_(2)O_(4)and PbS nanocomposite FTIR optical photoluminescence

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Impact of composition ratio on the structure and optical properties of(1-x)MnFe_(2)O_4/(x)ZnMn_(2)O_4 nanocomposite

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Chinese Physics B 2022年第7期31卷 481-489页

作者： Zein K.Heiba mohamed bakr mohamed Ali A.Alkathiri Sameh I.Ahmed A A Alhazime Department of Physics Faculty of ScienceAin shams UniversityCairo 11566Egypt Physics Department Faculty of ScienceTaibah UniversityAl-Madina al MunawarahSaudi Arabia Depatment of Physics College of ScienceTaif UniversityP.O.Box 11099Taif 21944Saudi Arabia

(1-x)MnFe_(2)O_(4)(MFO)/xZnMn_(2)O_(4)(ZMO)(x=0,0.2,0.5,0.8,and 1.0)nanocomposite samples were prepared using co-precipitation *** phase percentage,cell parameters,and crystallite size of MFO and ZMO phases in each nanocomposite sample were calculated using Rietveld refinement *** x-ray diffraction(XRD)analysis and Fourier-transform infrared spectroscopy techniques established the variation in the lattice parameters of each phase are due to permutation of all cations among the octahedral and tetrahedral sites of MFO and *** different oxidation states of different ions in all samples were determined using x-ray photoelectron spectroscopy(XPS)*** variation in absorbance of the nanocomposite samples with composition parameter(x)is dependent on the wavelength *** optical bandgap of the nanocomposite samples is decreased as the content of ZMO phase *** effect of alloying on the refractive index,extinction coefficient,dielectric constant,optical conductivity,and the nonlinear optical behaviors of all samples were studied in *** nanocomposite sample x=0.5 disclosed upgraded optical parameters with the highest refractive index,optical conductivity,and PL intensity,which nominate it to be functional in various application fields.

关键词： MFO and ZMO composite XPS structure optical

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Linearly and Quadratically Separable Classifiers Using Adaptive Approach

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Journal of Computer Science & Technology 2011年第5期26卷 908-918页

作者： mohamed Abdel-Kawy mohamed Ali Soliman Rasha M.Abo-bakr Department of Computer and Systems Engineering Faculty of EngineeringZagazig UniversityZagazigEgypt Departement of Mathematics Faculty of ScienceZagazig UniversityZagazigEgypt

This paper presents a fast adaptive iterative algorithm to solve linearly separable classification problems in R *** each iteration,a subset of the sampling data （n-points,where n is the number of features） is adaptively chosen and a hyperplane is constructed such that it separates the chosen n-points at a margin and best classifies the remaining *** classification problem is formulated and the details of the algorithm are ***,the algorithm is extended to solving quadratically separable classification *** basic idea is based on mapping the physical space to another larger one where the problem becomes linearly *** illustrations show that few iteration steps are sufficient for convergence when classes are linearly *** nonlinearly separable data,given a specified maximum number of iteration steps,the algorithm returns the best hyperplane that minimizes the number of misclassified points occurring through these *** with other machine learning algorithms on practical and benchmark datasets are also presented,showing the performance of the proposed algorithm.

关键词： linear classification quadratic classification iterative approach adaptive technique

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Salvadora persica extract attenuates cyclophosphamide-induced hepatorenal damage by modulating oxidative stress, inflammation and apoptosis in rats

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Journal of Integrative Medicine 2022年第4期20卷 348-354页

作者： Talat Albukhari Bassem Refaat El-Sayed bakr Sameh Baz Bodour Rajab Hossam Gadalla mohamed El-Boshy Department of Immunology and Hematology Faculty of MedicineUmm Al-Qura UniversityMakkah 21955Saudi Arabia Department of Laboratory Medicine Faculty of Applied Medical SciencesUmm Al-Qura UniversityMakkah 7607Saudi Arabia Clinical Nutrition Department Faculty of Applied Medical Sciences Umm Al-Qura UniversityMakkah 7607Soudi Arabia Clinical Pathology Department Faculty of Veterinary MedicineMansoura UniversityMansoura 35516Egypt

Objective: Salvadora persica(SP) is used as a food additive and is a common ingredient in folk *** study investigates the antioxidant, anti-inflammatory, and beneficial effects of SP against cyclophosphamide(CYP) toxicity in ***: In a 10-day study, 32 male rats were equally allocated into 4 groups(8 rats/group) as follows:the normal control(NC group), normal rats that only received oral aqueous extract of SP(100 mg/[kg·d];SP group), animals treated with intraperitoneal CYP injections(30 mg/[kg·d];CYP group), and the CYP + SP group that concurrently received CYP with SP aqueous extract. Serum samples were collected to measure the liver and renal biochemical profiles, as well as antioxidant and oxidative stress markers and the concentrations of interleukin-1β(IL-1β), IL-6, IL-10, tumor necrosis factor-a(TNF-a), nuclear factor-κB(NF-κB) and adenosine 5’-monophosphate-activated protein kinase(AMPK). Hepatic and renal tissues were also harvested for histopathology and to measure apoptosis using the terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling technique, alongside tissue levels of oxidative stress ***: Liver enzymes, total bilirubin, creatinine and urea, as well as serum IL-1β, IL-6, TNF-a and NF-κB increased significantly, whilst total protein, albumin, calcium, IL-10 and AMPK declined in serum of the CYP group relative to the NC group. The hepatorenal concentrations of glutathione, glutathione peroxidase and catalase declined markedly in the CYP group, whereas malondialdehyde, protein adducts, and apoptosis index increased compared with the NC group. By contrast, the hepatorenal biochemistry and apoptosis index of the SP group were comparable to the NC group. Interestingly, the CYP + SP group had significant improvements in the liver and renal biochemical parameters, enhanced anti-oxidative and anti-inflammatory effects, and marked declines in hepatic and renal apoptosis relative to the CYP group. Moreover, all mon

关键词： Cyclophosphamide Salvadora persica Cytokine NF-κB AMP-activated protein kinases Antioxidants Anti-inflammatory agents

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Effect of reperfusion strategy on QT dispersion in patients with acute myocardial infarction:Impact on in-hospital arrhythmia

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World Journal of Cardiology 2023年第3期15卷 106-115页

作者： mohamed Aboel-Kassem F Abdelmegid mohamed M bakr Hamdy Shams-Eddin Amr A Youssef Ahmed Abdel-Galeel Department of Cardiovascular Medicine Assiut University Heart HospitalAssiut UniversityAssiut 71526Egypt Department of Cardiology Sohag Heart and GIT CenterSohag 85264Egypt Department of Cardiology Assiut Police HospitalAssiut 71526Egypt Department of Cardiology Qena General HospitalQena 92354Egypt

BACKGROUND Myocardial ischemia and ST-elevation myocardial infarction(STEMI)increase QT dispersion(QTD)and corrected QT dispersion(QTcD),and are also associated with ventricular *** To evaluate the effects of reperfusion strategy[primary percutaneous coronary intervention(PPCI)or fibrinolytic therapy]on QTD and QTcD in STEMI patients and assess the impact of the chosen strategy on the occurrence of in-hospital *** This prospective,observational,multicenter study included 240 patients admitted with STEMI who were treated with either PPCI(group I)or fibrinolytic therapy(group II).QTD and QTcD were measured on admission and 24 hr after reperfusion,and patients were observed to detect in-hospital *** There were significant reductions in QTD and QTcD from admission to 24 hr in both group I and group II *** and QTcD were found to be shorter in group I patients at 24 hr than those in group II(53±19 msec vs 60±18 msec,P=0.005 and 60±21 msec vs 69+22 msec,P=0.003,respectively).The occurrence of in-hospital arrhythmia was significantly more frequent in group II than in group I(25 patients,20.8%vs 8 patients,6.7%,P=0.001).Furthermore,QTD and QTcD were higher in patients with in-hospital arrhythmia than those without(P=0.001 and P=0.02,respectively).CONCLUSION In STEMI patients,PPCI and fibrinolytic therapy effectively reduced QTD and QTcD,with a higher observed reduction using *** was associated with a lower incidence of in-hospital arrhythmia than fibrinolytic *** addition,QTD and QTcD were shorter in patients not experiencing in-hospital arrhythmia than those with arrhythmia.

关键词： Arrhythmia QT dispersion ST-segment elevation myocardial infarction Reperfusion Primary percutaneous coronary intervention Fibrinolytic therapy

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Early detection of hepatocellular carcinoma co-occurring with hepatitis C virus infection: A mathematical model

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World Journal of Gastroenterology 2016年第16期22卷 4168-4182页

作者： Abdel-Rahman Nabawy Zekri Amira Salah El-Din Youssef Yasser Mabrouk bakr Reham mohamed Gabr Ola Sayed Ahmed Mostafa Hamed Elberry Ahmed Mahmoud Mayla mohamed Abouelhoda Abeer A Bahnassy Molecular Virology and Immunology Unit Cancer Biology Department National Cancer Institute Cairo University Systems and Biomedical Engineering Department Faculty of Engineering Cairo University Center for Informatics Sciences Nile University Sheikh Zayed City Pathology Department National Cancer Institute Cairo University

AIM: To develop a mathematical model for the early detection of hepatocellular carcinoma (HCC) with a panel of serum proteins in combination with α-fetoprotein (AFP).METHODS: Serum levels of interleukin (IL)-8, soluble intercellular adhesion molecule-1 (sICAM-1), soluble tumor necrosis factor receptor II (sTNF-RII), proteasome, and β-catenin were measured in 479 subjects categorized into four groups: (1) HCC concurrent with hepatitis C virus (HCV) infection (n = 192); (2) HCV related liver cirrhosis (LC) (n = 96); (3) Chronic hepatitis C (CHC) (n = 96); and (4) Healthy controls (n = 95). The R package and different modules for binary and multi-class classifiers based on generalized linear models were used to model the data. Predictive power was used to evaluate the performance of the model. Receiver operating characteristic curve analysis over pairs of groups was used to identify the best cutoffs differentiating the different ***: We revealed mathematical models, based on a binary classifier, made up of a unique panel of serum proteins that improved the individual performance of AFP in discriminating HCC patients from patients with chronic liver disease either with or without cirrhosis. We discriminated the HCC group from the cirrhotic liver group using a mathematical model (-11.3 + 7.38 × Prot + 0.00108 × sICAM + 0.2574 × β-catenin + 0.01597 × AFP) with a cutoff of 0.6552, which achieved 98.8% specificity and 89.1% sensitivity. For the discrimination of the HCC group from the CHC group, we used a mathematical model [-10.40 + 1.416 × proteasome + 0.002024 × IL + 0.004096 × sICAM-1 + (4.251 × 10-4) × sTNF + 0.02567 × β-catenin + 0.02442 × AFP] with a cutoff 0.744 and achieved 96.8% specificity and 89.7% sensitivity. Additionally, we derived an algorithm, based on a binary classifier, for resolving the multi-class classification

关键词： Mathematical model Hepatocellular carcinoma α -fetoprotein Soluble intercellular adhesion molecule-1 β -catenin Interleukin-8 Soluble tumor necrosis factor receptor II Proteasome

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Influence of Nano-Barium Sulfate Agglomeration on Microstructure and Properties of the Hardened Cement-Based Materials

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Journal of Materials Science and Chemical Engineering 2015年第11期3卷 72-81页

作者： mohamed El-Shahate Ismaiel Saraya Inas Mostafa bakr Department of Chemistry Faculty of Science Al-Azhar University Cairo Egypt Faculty of Engineering Mattareya Helwan University Cairo Egypt

The aim of the present work is to study the effect of Nano-barium sulfate additions on the physic-mechanical properties of hardened cement pastes. Nano-barium sulfate was prepared by the precipitation method. Eight mixes of filled cement pastes containing 0.5 wt%, 1.0 wt%, 1.5 wt% and 2.0 wt% of both nano-barium sulfate and micro-limestone were prepared and compared to the base OPC. The hydration characteristics were evaluated by the measure of combined water content, bulk density, total porosity and compressive strength for samples hydrated up to 90 days. The progress of hydration reactions was followed up by XRD analysis. The morphology and microstructure were studied by SEM. Nano-size barium sulfate acted as a nucleating agent and enhanced the hydration of cement pastes up to 2.0% mass content. Also, the microstructure was improved considerably. Accordingly, nano-size barium sulfate can be used successfully in the preparation of filled cement.

关键词： Nano-Barium Sulfate Cement Paste Filler Compressive Strength Microstructure

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Assessment of natural radioactivity levels in Yemen rocks

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Journal of Environmental Science and Engineering 2009年第7期3卷 58-63页

作者： Haman mohamed Diab Abou bakr A. Ramadan Abdel-Hamed Osman National Centre for Nuclear Safety and Radiation Control Atomic Energy Authority Nasr 11762 Egypt Atomic Energy Authority Nasr 11762 Egypt Yemen Atomic Energy Authority Sana＇a 2579 Yemen

Studies on radiation level and radionuclide distribution in Yemen were studied. The samples were collected from eight locations： Ma＇rib, A1 Jawf, Sana＇a, Dhamar, Amran, Ibb, Al Bayda and Al Dalea. The purpose of this study is to provide a baseline map of radioactivity background levels in the investigated area and this study will be used as reference information to assess any change in the radioactive background level due to geological processes. The highest values of 22~ and 2~l＇h concentrations （8797.2 and 24984.1 ***＂l, respectively） were observed at A1 Jawf, region, whereas the highest average value of 40K concentration was 1561.9 ***-1. The investigation of the geological maps of the area under study showed that the surface rock outcrops consist mainly of granites, diorite, granodiorite, gneisses, and schists. All these rock types arc known to be rich in radioactive materials, which are considered natural sources for gamma radiation. The low mdiological background characterizing some Yemeni rocks could be attributed to nature of these rocks which consist of lime stone （sands and gravels）. The absorbed dose rate in air was found to be in the range between 5.40 and 45.11 nGy.h-1 depending on the geological features, and radium equivalent activity concentration was found in the range between 29.57 and 71.85 ***-1. Also the representative extcmal hazard index values for the corresponding samples were also estinlated and given.

关键词： natural radioactivity gamma radiation soil rock elemental concentration potassium thorium uranium

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On the Production Testing of Memristor Ratioed Logic (MRL) Gates

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Circuits and Systems 2016年第10期7卷 3016-3025页

作者： Ahmed Shukry Emara Ahmed Hassan Madian Hassanein Hamed Amer Sherif Hassanein Amer mohamed bakr Abdelhalim Electronics and Communications Engineering The American University in Cairo Cairo Egypt Radiation Energy Department Egyptian Atomic Energy Authority Cairo Egypt College of Computing and Information Technology AASTMT Cairo Egypt

This paper focuses on the production testing of Memristor Ratioed Logic (MRL) gates. MRL is a family that uses memristors along with CMOS inverters to design logic gates. Two-input NAND and NOR gates are investigated using the stuck at fault model for the memristors and the five-fault model for the transistors. Test escapes may take place while testing faults in the memristors. Therefore, two solutions are proposed to obtain full coverage for the MRL NAND and NOR gates. The first is to apply scaled input voltages and the second is to change the switching threshold of the CMOS inverter. In addition, it is shown that test speed and order should be taken into consideration. It is proven that three ordered test vectors are needed for full coverage in MRL NAND and NOR gates, which is different from the order required to obtain 100% coverage in the conventional NAND and NOR CMOS designs.

关键词： Memristors MRL Production Testing Fault Model Fault Coverage

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Urinary Vascular Endothelial Growth Factor (VEGF) as a Novel Marker for Early Prediction of Esophageal Varices in Patients with Chronic Liver Disease

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Open Journal of Gastroenterology 2017年第5期7卷 141-153页

作者： Yasser bakr mohamed Ula M. Al-Jarhi Mona Mohsen Sarah Ahmad El Morsy Department of Medicine Cairo University Cairo Egypt Department of Chemical Pathology Cairo University Cairo Egypt Mataria Hospital Cairo Egypt

Background/Aims: Vascular Endothelial Growth Factor (VEGF) has a crucial role in portal hypertension and collateral vessels formation. This study aims to assess urinary VEGF in cirrhotic patients as a predictor of presence of esophageal varices, and variceal bleeding. Settings and Design: 42 cirrhotic patients were randomly selected and classified into 2 groups according to the presence of variceal bleeding. Methods and Material: Urinary VEGF was measured and corrected against urinary creatinine. Platelet count, liver functions, abdominal ultrasonography and upper endoscopy were done. Statistical Analysis Used: Comparison was done by Mann Whitney and Kruskal Wallis tests. Correlation was done using Spearman rank correlation. Multivariable logistic regression was done to identify predictors of variceal bleeding and presence of large varices. Receiver operator characteristic curve (ROC) analysis was used to determine the optimum cut off value of predictors. Results and Conclusions: Urinary VEGF was lower in cirrhotic patients with esophageal varices than those without. Low VEGF, low platelet count and splenomegaly were found to be independent predictors of both the presence of large esophageal varices, and variceal bleeding. Cut-off values for platelet count ≤ 166.3 × 103/μL, and corrected VEGF ≤ 59.12 pg/mg were predictive of large esophageal varices with 93.1%, 86.2% sensitivity and 74.5%, 58.2% specificity respectively. While variceal bleeding could be predicted at a platelet count ≤ 153 × 103/μL, and corrected VEGF ≤ 45.08 pg/mg with 90.9%, 81.8% sensitivity and 72.6%, 59.7% specificity respectively. The study concludes that urinary VEGF can be used as an alternative to upper endoscopic screening.

关键词： Liver Cirrhosis Portal Hypertension Esophageal Varices VEGF Variceal Bleeding

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