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Gastrointestinal and hepatic diseases during the COVID-19 pandemic:Manifestations,mechanism and management

World Journal of Gastroenterology 2021年第28期27卷 4504-4535页

作者： Dina Zakaria Mohamed Mai El-Sayed Ghoneim Sally El-Sayed Abu-Risha ramy ahmed abdelsalam Mohamed Abdelhalem Farag Department of Pharmacology and Toxicology Faculty of PharmacyTanta UniversityTanta 31511Egypt Department of Pharmacology and Toxicology Faculty of PharmacyUniversity of Sadat CityMenoufia 32632Egypt Department of Pathology Faculty of MedicineMansoura UniversityMansoura 35511Egypt Department of Pediatrics Nebru General HospitalNebru 35511Egypt

Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)is considered the causative pathogen of coronavirus disease 2019(COVID-19)and has become an international danger to human *** respiratory transmission and symptoms are still the essential manifestations of COVID-19,the digestive system could be an unconventional or supplementary route for COVID-19 to be transmitted and manifested,most likely due to the presence of angiotensin-converting enzyme 2(ACE2)in the gastrointestinal *** addition,SARS-CoV-2 can trigger hepatic injury via direct binding to the ACE2 receptor in cholangiocytes,antibodydependent enhancement of infection,systemic inflammatory response syndrome,inflammatory cytokine storms,ischemia/reperfusion injury,and adverse events of treatment *** symptoms,including anorexia,nausea,vomiting,and diarrhea,which are unusual in patients with COVID-19,and some digestive signs may occur without other respiratory ***,SARS-CoV-2 can be found in infected patients’stool,demonstrating the likelihood of transmission through the fecal-oral *** addition,liver function should be monitored during COVID-19,particularly in more severe *** review summarizes the evidence for extra-pulmonary manifestations,mechanisms,and management of COVID-19,particularly those related to the gastrointestinal tract and liver.

关键词： COVID-19 Angiotensin-converting enzyme 2 Gastrointestinal Inflammatory bowel disease Liver Management

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From seawater to hydrogen via direct photocatalytic vapor splitting: A review on device design and system integration

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Frontiers in Energy 2024年第3期18卷 291-307页

作者： Hongxia LI Khaja WAHAB ahmed Mohamed A.abdelsalam Michael FOWLER Xiao-Yu WU Technology Innovation Institute Masdar CityAbu Dhabi 9639United Arab Emirates Department of Chemical Engineering University of WaterlooWaterlooON N2L 3G1Canada Department of Mechanical and Nuclear Engineering Khalifa University of Science and TechnologyAbu Dhabi 127788United Arab Emirates Department of Mechanical and Mechatronics Engineering University of WaterlooWaterlooON N2L 3G1Canada

Solar-driven hydrogen production from seawater attracts great interest for its emerging role in decarbonizing global energy consumption. Given the complexity of natural seawater content, photocatalytic vapor splitting offers a low-cost and safe solution, but with a very low solar-to-hydrogen conversion efficiency. With a focus on cutting-edge photothermal–photocatalytic device design and system integration, the recent research advances on vapor splitting from seawater, as well as industrial implementations in the past decades were reviewed. In addition, the design strategies of the key processes were reviewed, including vapor temperature and pressure control during solar thermal vapor generation from seawater, capillary-fed vaporization with salt repellent, and direct photocatalytic vapor splitting for hydrogen production. Moreover, the existing laboratory-scale and industrial-scale systems, and the integration principles and remaining challenges in the future seawater-to-hydrogen technology were discussed.

关键词： seawater hydrogen photocatalytic vapor splitting solar-driven

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Steady-State Performance Evaluation of Linux TCPs versus TCP Wave over Leaky Satellite Links

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China Communications 2017年第3期14卷 17-30页

作者： ahmed abdelsalam Cesare Roseti Francesco Zampognaro Department of Electronics Engineering University of Rome "Tor Vergata" Via del Politecnico 1 Rome 00133 Italy

Internet access is becoming even more heterogeneous, including different wireless backhauling links, with Ka-band satellites as a possible alternative. Since communication path is unknown a priori, adoption of PEP solutions to optimize TCP performance over satellite is discouraged to allow dynamic network reconfigurations. To opposite, an endto-end TCP performance evaluation on such a challenging scenario, with possible large latency and transmission losses, is herein considered of paramount importance. Several TCP variants exist to tackle different aspects of communication networks. In Linux, the different TCP congestion control schemes differ from the theoretical formulations and RFC specifications, introducing a varying set of optimizations and options. This aspect makes difficult to identify a standard/reference TCP version for the proposed scenario, while testing with the real protocol stacks is deemed necessary to obtain consistent results. In addition, an innovative end-to-end TCP, namely TCP Wave, is introduced to replace the traditional window-based transmission with a burst-based strategy, representing a valid alternative to Linux TCP. To offer a fair, realistic and comprehensive evaluation, we configured a simulation setup where different Linux TCPs can be run within ns-3 network simulator and compared with TCP Wave.

关键词： TCP satellite internet leaky channels Linux ns-3

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Virtual orthopedic assessment:Main principles and specific regions

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World Journal of Orthopedics 2021年第9期12卷 672-684页

作者： Khaled M Emara ramy ahmed Diab Mohamed Amr Shady Abdelghaffar Mahmoud Mohamed Nour ahmed abdelsalam Mahmoud ahmed Elshobaky Mona Farhan Mostafa Gemeah ahmed K Emara Orthopedic Surgery Department Ain Shams UniversityCairo 11566Egypt Orthopedic Surgery Department Bank Ahly HospitalCairo 11566Egypt Department of Health Care Innovation Arizona State UniversityArizonaAZ 85287United States Department of Orthopedic Surgery Cleveland ClinicOhioNY 44195United States

Telemedicine was originally created as a way to treat patients who were located in remote places far away from local health facilities or in areas with shortages of medical *** is still used today to address those problems,and is increasingly becoming a tool for convenient medical *** the emergence of pandemics,telemedicine became almost a mandatory and valuable option for continuing to provide medical care in various *** the threat of pandemic progress has continued for months and may continue for years,it is essential to validate existing tools to maintain clinical assessment and patient treatment to avoid negative consequences of the lack of medical ***,the establishment of a virtual assessment technique that can be conducted effectively is of outmost importance as a way of adapting to the current *** study evaluated the role of telemedicine in the assessment of various orthopedic pathologies by means of a systematic virtual evaluation.

关键词： Telemedicine Virtual assessment Orthopedics Epidemic diseases

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Effect of heat input and filler metals on weld strength of gas tungsten arc welding of AISI 316 weldments

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China Welding 2020年第1期29卷 8-16页

作者： Essam ahmed ramy ahmed A EL-Nikhaily A R S Essa Metallurgical and Materials Engineering Department Faculty of Petroleum and Mining EngineeringSuez University43721 Egypt Mechanical Department Faculty of Industrial EducationSuez University43721 Egypt Mechanical Engineering Department Egyptian Academy for Engineering&Advanced TechnologyAffiliated to Ministry of Military ProductionCairo 3056Egypt

The present work investigates the effect of filler metals and heat input on weld bead geometry and mechanical properties of alloy316 welded by using ***309 L,ER316 L and ERNi Cr Mo-3 filler metals,are applied to study their effect on the *** defects are examined using radiographic *** mechanical properties of welds are evaluated through uniaxial testing,hardness measuring,and bending *** mechanical properties and cooling rate decrease with increasing heat *** strength,yield stress and percentage elongation of weldments using three fillers are *** results are obtained using ERNi Cr ***,weld nugget area,cooling time and solidification time increases with increasing heat ***,applying bending test on weld samples,cracks,tearing and surface defects are not observed.

关键词： TIG welding filler metals nugget area stainless steel cooling rate

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Chemical stability, thermal behavior, and shelf life assessment of extruded modified double-base propellants

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Defence Technology（防务技术） 2018年第1期14卷 70-76页

作者： Sherif Elbasuney ahmed Fahd Hosam E.Mostafa Sherif F.Mostafa ramy Sadek School of Chemical Engineering Military Technical College

Double base propellant suffers from lack of chemical stability; this could result in self ignition during storing. Modified double base(MDB) propellant based on stoichiometric binary mixture of oxidizermetal fuel(Ammonium perchlorate/Aluminum), and energetic nitramines(HMX) offered enhanced thrust as well as combustion characteristics. This study is devoted to evaluate the impact of such energetic additives on thermal behavior, chemical stability, and shelf life. Extruded MDB formulations were manufactured by extrusion process. Artificial aging at 80℃ for 28 days was conducted. Shelf life assessment was performed using Van't Hoff's equation. Quantification of evolved NOxgases with aging time was performed using quantitative stability tests. MDB formulation based on HMX demonstrated extended service life of 16 years compared with(AP/Al)-MDB which demonstrated 9 years. This finding was ascribed to the reactivity of AP with nitroglycerin with the formation of perchloric acid. Thermal behavior of aged MDB, exhibited an increase in heat released with time; this was ascribed to the autocatalytic thermal degradation during artificial aging. The increase in released heat by 31% was found to be equivalent to evolved NOx gases of 6.2 cm^3/5 g and 2.5 cm^3/1 g for Bergmann-Junk test, and Vacuum stability test respectively. This manuscript shaded the light on a novel approach to quantify evolved NOx gases to heat released with aging time. MDB based on HMX offered balanced ballistic performance,chemical stability, and service life.

关键词： Double-base Chemical stability Thermal behavior Artificial aging Shelf life assessment

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Novel colored flames via chromaticity of essential colors

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Defence Technology（防务技术） 2019年第2期15卷 210-215页

作者： ramy Sadek Mohamed Kassem Mohamed Abdo ahmed Fahd Hesham Tantawy Amir Elsaidy Sherif Elbasuney School of Chemical Engineering Military Technical College

Colored flame compositions have distinctive variety of applications ranging from military signaling,rocket tracking, and illuminating devices. Certain elements and compounds when heated to high temperature are able to emit unique wavelengths in the visible region. This study, reports on the development of novel colored flames that cannot be generated by emitting atomic/molecular species. This was achieved by using chromaticity of basic colored flames. Mixing of high quality primary colored flames including Blue, Yellow, and Red in proper ratio was conducted; any interfering incandescent emission resulted from MgO was eliminated using Al metal fuel. The spectral characteristics in terms of luminous intensity, and color quality were evaluated using digital luxmeter and UV-Vis. spectrometer *** quality mixed colored flames include violet, sweet pink, and marigold were developed. This study shaded the light on the state of the art for the real development of novel colored flame compositions and chromaticity of basic colored flames.

关键词： Pyrotechnics Colored flame Atomic spectroscopy Molecular spectroscopy Luminous intensity Color quality Chromaticity

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Ion-acoustic waves at the night side of Titan's ionosphere:higher-order approximation

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Communications in Theoretical Physics 2020年第5期72卷 70-77页

作者： S M ahmed E R Hassib U M abdelsalam R E Tolba W M Moslem Department of Mathematics Faculty of ScienceSuez UniversitySuezEgypt Department of Mathematics Faculty of ScienceFayoum UniversityFayoumEgypt Department of Mathematics Rustaq College of EducationOman Centre for Theoretical Physics The British University in Egypt(BUE)El-Shorouk CityCairoEgypt Department of Physics Faculty of SciencePort Said UniversityPort Said 42521Egypt

Nonlinear solitary waves are investigated for a plasma system at the night side of Titan's *** plasma model consists of three positive ions,namely C2H5^+,HCNH^+,and C3H5^+,as well as Maxwellian *** basic set of fluid equations is reduced to a Korteweg de-Vries(KdV)equation and linear inhomogeneous higher order KdV(LIHO-KdV)*** solitary wave solutions of both equations are obtained using a renormalization *** solitary waves'existence region and the wave profile are investigated,and their dependences on the plasma parameters at the night side of Titan's ionosphere are *** solitary waves'phase velocities are subsonic or supersonic,and the propagating pulses are usually *** effect of higher-order corrections on the perturbation theory is *** is found that the higher-order contribution makes the amplitude slightly taller,which is suitable for describing the solitary waves when the amplitude augments.

关键词： plasmas ion-acoustic waves planets and satellites:atmospheres

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Novel aspects for thermal stability studies and shelf life assessment of modified double-base propellants

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Defence Technology（防务技术） 2019年第3期15卷 300-305页

作者： Sherif Elbasuney Ashraf.M. A. Elghafour Mostafa Radwan ahmed Fahd Hosam Mostafa ramy Sadek Amr Motaz School of Chemical Engineering Military Technical College Kobry El-Kobba Cairo Egypt British University in Egypt Elshrouk city Cairo Egypt

Modified DB propellants, based on energetic nitramine(RDX) were manufactured by solventless extrusion process. Thermal stability and shelf life assessment of modified DB propellant were investigated. Shelf life assessment was evaluated using Van’t Hoff’s formula and artificial aging at 70℃ up to120 days. Quantification of total heat released and heat flow with aging time was conducted using differential scanning calorimetry(DSC) and thermal activity monitoring(TAMIII) respectively. Modified DB formulation based on 20 wt % RDX demonstrated enhanced thermal stability in terms of controlled heat flow, and slow decomposition reactions at elevated temperature. This formulation demonstrated extended service life up to 56 years compared with reference formulation. These novel finding was ascribed to the high thermal stability of RDX and its compatibility with DB constituents. This manuscript shaded the light on novel and effective approach for thermal stability via monitoring thermal activity with aging.

关键词： Double-base propellant Thermal stability Artificial aging Shelf-life assessment

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Cystic pancreatic lesions,the endless dilemma

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World Journal of Gastroenterology 2021年第21期27卷 2664-2680页

作者： Hussein Hassan Okasha Abeer Awad ahmed El-meligui Reem Ezzat Ashraf Aboubakr Sameh AbouElenin ramy El-Husseiny ahmed Alzamzamy Department of Internal Medicine and Gastroenterology Hepatology UnitKasr Al-Aini HospitalsCairo UniversityCairo 11562Egypt Department of Internal Medicine and Gastroenterology Hepatology UnitAssuit UniversityAssuit 71515Egypt Department of Gastroenterology and Hepatology Maadi Armed Forces Medical ComplexMilitary Medical AcademyCairo 11441Egypt Department of Gastroenterology and Hepatology Military Medical AcademyCairo 11441Egypt Department of Hepatology and Tropical Medicine National Hepatology and Tropical Medicine Research Institute(NHTMRI)Cairo 11441Egypt

Cystic pancreatic lesions involve a wide variety of pathological entities that include neoplastic and non-neoplastic *** proper diagnosis,differentiation,and staging of these cystic lesions are considered a crucial issue in planning further *** are great challenges for their diagnostic *** our time,new emerging methods for this diagnosis have been *** ultrasonography-guided fine-needle aspiration cytology with chemical and molecular analysis of cyst fluid and EUS-guided fine needlebased confocal laser endomicroscopy,through the needle microforceps biopsy,and single-operator cho-langioscopy/pancreatoscopy are promising methods that have been used in the diagnosis of cystic pancreatic *** we discuss the diagnosis of cystic pancreatic lesions and the benefits of various diagnostic models.

关键词： Pancreatic cystic lesion Endoscopic diagnosis Endoscopic ultrasonography Cyst fluid markers Endoscopic ultrasonography-guided fine needle-based confocal laser endomicroscopy Through the needle microforceps biopsy Single operator cholangioscopy/pancreatoscopy

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