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Investigation of a Modified Cobalt-Free Alloy for Nuclear Application

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Journal of Materials Science and Chemical Engineering 2015年第9期3卷 52-56页

作者： Mamdouh mahmoud eissa Maged mahmoud Kassab Samir Uoshaa El-Kameesy Ahamed Abdel-Latif Mohamed Department of Steel and Ferroalloys CMRDI Helwan Egypt Department of Physics Faculty of Engineering Fayoum University Fayoum Egypt Department of Physics Faculty of Science Ain Shams University Cairo Egypt

Cobalt-free alloy of constituent’s “0.045%C-12.73%Ni-6.53%Cr-3.2%Mo-0.02%Ti-0.01%V” has been prepared by electro slag remelting technique. Mass attenuation coefficient, half value layer and effective atomic number have been determined for the prepared sample at photon energies 235 - 2700 keV. The results are compared with the corresponding theoretical calculations based on XCOM program and a fair agreement is obtained.

关键词： Cobalt Free Gamma Shielding Effective Atomic Number Mass Attenuation Coefficient

Quintic B-Spline Method for Solving Sharma Tasso Oliver Equation

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Journal of Applied Mathematics and Physics 2022年第12期10卷 3920-3936页

作者： Talaat S. Eldanaf Mohamed Elsayed mahmoud A. eissa Faisal Ezz-Eldeen Abd Alaal Department of Mathematics and Computer Science Faculty of Science Menoufia University Shebin El-Kom Egypt Basic Science Department School of Engineering Canadian International College “CIC” Giza Egypt Department of Mathematics Faculty of Science Damanhour University Damanhour Egypt

When analysing the thermal conductivity of magnetic fluids, the traditional Sharma-Tasso-Olver (STO) equation is crucial. The Sharma-Tasso-Olive equation’s approximate solution is the primary goal of this work. The quintic B-spline collocation method is used for solving such nonlinear partial differential equations. The developed plan uses the collocation approach and finite difference method to solve the problem under consideration. The given problem is discretized in both time and space directions. Forward difference formula is used for temporal discretization. Collocation method is used for spatial discretization. Additionally, by using Von Neumann stability analysis, it is demonstrated that the devised scheme is stable and convergent with regard to time. Examining two analytical approaches to show the effectiveness and performance of our approximate solution.

关键词： Nonlinear Partial Differential Equations Sharma-Tasso-Olver (STO) Equation Quintic B-Spline Collocation Method Von Neumann Stability Analysis

Early clinical outcomes of two regimens of prophylactic antibiotics in cardiac surgical patients with delayed sternal closure

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World Journal of Critical Care Medicine 2024年第3期13卷 32-41页

作者： mahmoud Ismail Allam eissa Rasha Kaddoura Danial Hassan Cornelia S Carr Samy Hanoura Yasser Shouman Abdulwahid Almulla Amr Salah Omar Department of Cardiothoracic Surgery Hamad Medical CooperationDoha 3050Qatar Department of Anesthesia and Intensive Care Al-Azhar UniversityCairo 11651Egypt Department of Pharmacy Heart HospitalHamad Medical CorporationDoha 3050Qatar Department of Healthcare Profession Harvard TH Chan School of Public HealthMinistry of Public HealthBostonMA 3050United States Department of Surgery Qatar UniversityDoha 3050Qatar Department of Cardiac Anesthesia Hamad Medical CorporationDoha 3050Qatar Department of Anesthesia Weill Cornell Medical College in QatarDoha 3050Qatar Department of Critical Care Medicine Beni Suef UniversityBeni Suef 62521Egypt Department of Medicine Weill Cornell Medical College in QatarDoha 3050Qatar

BACKGROUND Delayed sternal closure(DSC)can be a lifesaving approach for certain patients who have undergone cardiac *** value of the type of prophylactic antibiotics in DSC is still *** To investigate clinical outcomes of different prophylactic antibiotic regimens in patients who had DSC after cardiac *** This was a retrospective observational single-center ***-three consecutive patients who underwent cardiac surgery and had an indication for DSC were *** were subjected to two regimens of antibiotics:Narrow-spectrum and broad-spectrum *** The main outcome measures were length of hospital and intensive care unit(ICU)stay,duration of mechanical ventilation,and *** the 53 patients,12(22.6%)received narrow-spectrum antibiotics,and 41(77.4%)received broad-spectrum *** mean age was 59.0±12.1 years,without significant differences between the *** mean duration of antibiotic use was significantly longer in the broad-spectrum than the narrowspectrum group(11.9±8.7 vs 3.4±2.0 d,P<0.001).The median duration of open chest was 3.0(2.0-5.0)d for all patients,with no difference between groups(P=0.146).The median duration of mechanical ventilation was significantly longer in the broad-spectrum group[60.0(Δinterquartile range(IQR)170.0)h vs 50.0(ΔIQR 113.0)h,P=0.047].Similarly,the median length of stay for both ICU and hospital were significantly longer in the broadspectrum group[7.5(ΔIQR 10.0)d vs 5.0(ΔIQR 5.0)d,P=0.008]and[27.0(ΔIQR 30.0)d vs 19.0(ΔIQR 21.0)d,P=0.031].Five(9.8%)patients were readmitted to the ICU and 18(34.6%)patients died without a difference between *** Prophylactic broad-spectrum antibiotics did not improve clinical outcomes in patients with DSC post-cardiac surgery but was associated with longer ventilation duration,length of ICU and hospital stays vs narrow-spectrum antibiotics.

关键词： Cardiac surgery Delayed sternal closure Intensive care Open chest Prophylactic antibiotics

Occurrence and ecotoxicological risk assessment of pesticides in sediments of the Rosetta branch,Nile River, Egypt

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Journal of Environmental Sciences 2022年第8期34卷 21-31页

作者： Fawzy eissa mahmoud Al-Sisi Khaled Ghanem Environment and Bio-agriculture Department Faculty of AgricultureAl-Azhar UniversityNasr CityCairo 11884Egypt Central Laboratory of Residue Analysis of Pesticides and Heavy Metals in Food(QCAP) Agricultural Research CenterDokkiGiza 12311Egypt

This study aimed to(1) monitor the occurrence and spatiotemporal variations of 100 pesticides in sediments collected monthly from July 2018 to June 2019 from sampling sites in El-Rahawy, Sabal, and Tala, along the Rosetta branch of the Nile River, Egypt, and(2) perform an ecological risk assessment for aquatic organisms upon exposure to the detected sediment pesticides based on the risk quotient(RQ) method. Out of the 100 pesticides monitored, 16 pesticides belonging to seven chemical families were detected, and 55% of the sediment samples were contaminated with one or more pesticide residues. The mean concentration(mg/kg dry weight(dw)) and detection frequency(%) of the four most frequently detected pesticides in the sediment samples were as follows: chlorpyrifos(0.18 mg/kg dw and 34%), p,p-DDE(0.018 mg/kg dw and 30%), cypermethrin(0.03 mg/kg dw and 14%), and deltamethrin(0.026 mg/kg dw and 13%). The spatial distribution exhibited that El-Rahawy had the highest pesticide load(2.86 mg/kg dw) among the studied sites, whereas the temporal variations revealed that the highest total pesticide concentrations were detected in winter season(1.73 mg/kg dw). Meanwhile, 12 pesticides showed high RQs(>1), posing a potential ecological risk to aquatic species that live and feed on such sediments.

关键词： Pesticide residues Sediments Spatiotemporal variations Risk quotient

Study of parameters affecting infection risk from contaminated injectable products using multiple spot contamination model: a case study of insulin vials

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Journal of Chinese Pharmaceutical Sciences 2016年第11期25卷 832-837页

作者： Mostafa Essam eissa Hikma Pharma for Pharmaceutical Industry 2nd Industrial Zone

Infections of patients from consumption of contaminated pharmaceutical products constituted major health risk problems. Medicinal products are liable to microbial intrusion during in-use application. The current study focused on repeated contamination with constant level of microbiological burden by two bacteria viz. Staphylococcus aureus and Pseudomonas aeruginosa were used as dose-response models for infection through two different routes of administration. Nine different forms of insulin vials were subjected to this type of simulation study at constant assumed level of contaminations, preservative efficacy test(PET) and dose potency. Multi-spot contamination imitation study showed that initial fast rise in contamination, followed shortly by longer but steeper slope which finally turned into higher rate of contamination during the few last doses of the unit dosage forms, where the volume of the product became increasingly and progressively very small. When the probability of infection curves was constructed, both S. aureus and P. aeruginosa showed same pattern, with notably higher risk from septicemia route of the latter rather than subcutaneous route of the former. The present simulation study showed that continuous use of the same contaminated syringe progressively increased the risk of infection, especially at final few doses(between 3th and 10 th last doses depending on the dosage form sizes in the vials and the administration volumes) of the product. Small volume parenterals(SVP) are especially products at higher risk than the larger volume ones.

关键词： Insulin vials Staphylococcus aureus Pseudomonas aeruginosa Multi-spot contamination PET Simulation study

Mid-term results of sub-trochanteric valgus osteotomy for symptomatic late stages Legg-Calvé-Perthes disease

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World Journal of Orthopedics 2023年第5期14卷 328-339页

作者： Khaled M Emara Ramy Ahmed Diab Ahmed K Emara Mohamed eissa Mostafa Gemeah Shady Abdelghaffar mahmoud Department of Orthopedic Surgery Ain Shams UniversityCairo 11591Egypt Department of Orthopedic Surgery Cleveland Clinic FoundationClevelandOH 9500United States Health Care Innovation Program Arizona State UniversityTempeAZ 85287United States

BACKGROUND The treatment of late stages of Legg-Calvé-Perthes disease(LCPD)is *** the concept of femoral head containment is a well-established technique of treatment,its use remains debatable in the late stages of the disease,as it does not improve symptoms in terms of limb length discrepancy and *** To assess the results of subtrochanteric valgus osteotomy in symptomatic patients with late-stage Perthes *** From 2000 to 2007,36 symptomatic patients with late stage of Perthes disease were surgically treated with subtrochanteric valgus osteotomy and followed-up for 8 to 11 years using the IOWA score and range of motion(ROM)*** Mose classification was also assessed at the last follow-up to reflect possible *** patients were 8 years old or older at the time of surgery,in the post-fragmentation stage,and complaining of pain,limited ROM,Trendelenburg gait,and/or abductor *** The preoperative IOWA score(average:53.3)markedly improved at the 1-year post follow-up period(average:85.41)and then slightly improved at the last follow-up(average:89.4)(P value<0.05).ROM improved,with internal rotation increased on average by 22°(from 10°preoperatively to 32°postoperatively)and abduction increased on average by 15.9°(from 25°preoperatively to 41°postoperatively).The mean Mose deviation of femoral heads was 4.1 mm at the end of the follow-up *** tests used were the paired t-test and Pearson correlation test,where the level of significance was a P value less than *** Subtrochanteric valgus osteotomy can be a good option for symptomatic relief in patients with late-stage of LCPD.

关键词： Legg-Calvé-Perthes disease Femoral head avascular necrosis Valgus osteotomy Deformity correction Post fragmentation stage Late stage Perthes

A Metaheuristic Technique for Cluster-Based Feature Selection of DNA Methylation Data for Cancer

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Computers, Materials & Continua 2023年第2期74卷 2817-2838页

作者： Noureldin eissa Uswah Khairuddin Rubiyah Yusof Ahmed Madani Centre for Artificial Intelligence&Robotics Malaysia-Japan International Institute of TechnologyUniversiti Teknologi MalaysiaKuala Lumpur54100Malaysia Department of Computer Engineering Arab Academy for ScienceTechnology and Maritime TransportCairo2033Egypt Department of Mechanical Precision Engineering Malaysia-Japan International Institute of TechnologyUniversiti Teknologi MalaysiaKuala Lumpur54100Malaysia

Epigenetics is the study of phenotypic variations that do not alter DNA *** epigenetics has grown rapidly over the past few years as epigenetic alterations exist in all human *** of these alterations is DNA methylation;an epigenetic process that regulates gene expression and often occurs at tumor suppressor gene loci in ***,studying this methylation process may shed light on different gene functions that cannot otherwise be interpreted using the changes that occur in DNA ***,microarray technologies;such as Illumina Infinium BeadChip assays;are used to study DNA methylation at an extremely large number of varying *** each DNA methylation site,a beta value(β)is used to reflect the methylation ***,clustering this data from various types of cancers may lead to the discovery of large partitions that can help objectively classify different types of cancers aswell as identify the relevant loci without user *** study proposed a Nested Big Data Clustering Genetic Algorithm(NBDC-GA);a novel evolutionary metaheuristic technique that can perform cluster-based feature selection based on the DNA methylation *** efficacy of the NBDC-GA was tested using real-world data sets retrieved from The Cancer Genome Atlas(TCGA);a cancer genomics program created by the NationalCancer Institute(NCI)and the NationalHuman Genome Research *** performance of the NBDC-GA was then compared with that of a recently developed metaheuristic Immuno-Genetic Algorithm(IGA)that was tested using the same data *** NBDC-GA outperformed the IGA in terms of convergence ***,the NBDC-GA produced a more robust clustering configuration while simultaneously decreasing the dimensionality of features to a maximumof 67%and of 94.5%for individual cancer type and collective cancer,*** proposed NBDC-GA was also able to identify two chromosomes with highly contrastingDNAmethylations activities th

关键词： Cancer clustering DNA methylation feature selection metaheuristic technique the cancer genome atlas

Active control of an aircraft tail subject to harmonic excitation

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Acta Mechanica Sinica 2007年第4期23卷 451-462页

作者： M.eissa H.S.Bauomy Y.A.Amer Department of Engineering Mathematics Faculty of Electronic EngineeringMenouf 32952Egypt Department of Mathematics Faculty of ScienceZagazig UniversityZagazigEgypt

Vibration of structures is often an undesirable phenomena and should be avoided or controlled. There are two techniques to control the vibration of a system, that is, active and passive control techniques. In this paper, a negative feedback velocity is applied to a dynamical system, which is represented by two coupled second order nonlinear differential equations having both quadratic and cubic nonlinearties. The system describes the vibration of an aircraft tail. The system is subjected to multi-external excitation forces. The method of multiple time scale perturbation is applied to solve the nonlinear differential equations and obtain approximate solutions up to third order of accuracy. The stability of the system is investigated applying frequency response equations. The effects of the different parameters are studied numerically. Various resonance cases are investigated. A comparison is made with the available published work.

关键词： Active vibration control Stability Response curves Aircraft tail

Aerodynamic and solid flow properties for flaxseeds for pneumatic separation by using air stream

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International Journal of Agricultural and Biological Engineering 2009年第4期2卷 31-45页

作者： Ayman Hafiz Amer eissa Agriculture Engineering Department Faculty of AgricultureMinoufiya UniversityShibin El-Kom32516EGYPT

This study aimed to develop simple empirical equations to predict flaxseeds *** first part of the present study deals with the physical,aerodynamic and solid flow properties of flaxseeds which are evaluated as a function of change in moisture content from 8.60%to 23.90%dry basis(d.b.),the dimensions of the length,width and thickness varied from 4.14 to 4.32 mm,2.03 to 2.13 mm and 0.88 to 0.93 mm,*** the moisture content increased from 8.60%to 23.90%d.b.,the bulk density,true density and porosity were found to decrease from 46.65 to 44.89 kg/m3;1244 to 1176 kg/m3 and 46.65%to 44.89%,whereas angle of repose and terminal velocity were found to increase from 27.60 to 35.80 and 2.46 to 3.56 m/s,*** static coefficient of friction on various surfaces,namely,plywood,stainless steel,galvanized iron,iron and internal also increased linearly with the increase in moisture *** results of the experimental investigation may help to optimize some engineering parameters of separation *** second part was carried out on a series of experiments to specify the optimum conditions of separating operation which insure the highest grade of separation efficiency with minimum *** separation equipment was manufactured and tested under different combinations of the following factors:air stream velocity,feed rate and sample moisture *** performance of the equipment was evaluated by using the indices separation efficiency and percentage of seed *** results of the equipment performances showed that the combinations of air stream velocity,feed rate and sample moisture content affected significantly the separation efficiency and grain *** stream velocity of 2-6 m/s combined with 8.5 kg/*** rate and 8.6%moisture content can be considered the most favorable combination values of these *** gave the highest grades of separation efficiency and the minimum grain losses.

关键词： flaxseed physical property aerodynamics solid flow properties pneumatic separation