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A focus on parietal cells as a renewing cell population

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World Journal of Gastroenterology 2010年第5期16卷 538-546页

作者： sherif M Karam department of Anatomy Faculty of Medicine and Health Sciences United Arab Emirates University Al-Ain PO Box 17666 United Arab Emirates

The fact that the acidsecreting parietal cells undergo continuous renewal has been ignored by many gastroenterologists and cell biologists. In the past, it was thought that these cells were static. However, by using 3Hthymidine radioautography in combination with electron microscopy, it was possible to demonstrate that parietal cells belong to a continuously renewing epithelial cell lineage. In the gastric glands, stem cells anchored in the isthmus region are responsible for the production of parietal cells. The stem cells give rise to three main progenitors: prepit, preneck and preparietal cells. Parietal cells develop either directly from the noncycling preparietal cells or less commonly via differentiation of the cycling prepit and preneck cell progenitors. The formation of a parietal cell is a sequential process which involves diminishment of glycocalyx, production of cytoplasmic tubulovesicles, an increase in number and length of microvilli, an increase in number and size of mitochondria, and fi nally, expansion and invagination of the apical membrane with the formation of an intracellular canalicular system. Little is known about the genetic counterparts of these morphological events. However, the time dimension of parietal cell production and the consequences of its alteration on the biological features of the gastric gland are well documented. The production of a new parietal cell takes about 2 d. However, mature parietal cells have a long lifespan during which they migrate bidirectionally while their functional activity for acid secretion gradually diminishes. Following an average lifespan of about 54 d, in mice, old parietal cells undergo degeneration and elimination. Various approaches for genetic alteration of the development of parietal cells have provided evidence in support of their role as governors of the stem/progenitor cell proliferation and differentiation programs. Revealing the dynamic features and the various roles of parietal cells would help

关键词： Cell differentiation Cell dynamics Cell renewal Oxyntic gland Oxyntic mucosa Parietal cell Preparietal cell

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Journal of Materials Science & Technology 2022年第1期96卷 248-261页

作者： Seyedmohammad Tabaie Farhad Rézaï-Aria Bertrand C.d.Flipo Mohammad Jahazi department of Mechanical Engineering École de Technologie Supérieure(ÉTS)H3C 1K3 MontrealQCCanada Institut Clément Ader(ICA) Universitéde ToulouseCNRSIMT Mines AlbiINSAUPSISAECampus Jarlard81013 AlbiFrance TWI Ltd Granta ParkGreat AbingtonCambridge CB216ALUnited Kingdom

The continuous growth in the manufacture of aerospace components such as blisks has led to an increase in the application of different hybrid materials fabricating methods,and thus the requirements for joining and strengthening of dissimilar *** to this goal,selective laser melted(SLM)Inconel718 was joined with forged Ad730^(TM)Nickel-based superalloy through linear friction welding(LFW)in this *** variation,specifically with respect to secondary phases precipitation was *** microhardness and strengthening mechanisms of the weldment were also *** precipitation(volume fraction and size of particles)at different regions of both sides of the weld line was *** to the weld line,the dissolution ofγ’/γ"and Laves phases and grain refinement occurred which reveals the effects of both compression strain and high temperature on recrystallization and high degree of elemental diffusion in the weld zone(WZ).It is shown that the size,volume fraction,and shape of secondary phases increased and changed(from spherical to long-striped for Laves particles)as we went from the WZ toward the base ***,the measured microhardness indicated that the strength of Ad730^(TM)alloy depends significantly on the grain size,while strength in SLM Inconel 718 was dominated by shape(or size)and the presence of secondary phases(γ’/γ"and Laves).

关键词： Additive manufacturing Linear friction welding Ni-based superalloy Precipitation Microhardness Strengthening mechanisms

Evaluation of axis alignment and refractive results of toric phakic IOL using image-guided system

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International Journal of Ophthalmology(English edition) 2020年第4期13卷 667-670页

作者： sherif Emerah Ophthalmology department Research Institute of OphthalmologyGizaEgypt Magrabi Eye Hospital DubaiUAE

AIM: To evaluate accuracy of axis alignment and refractive results of toric phakic intraocular lens(IOL) implantation using a digital imaging system. METHOdS: This retrospective study investigated toric implantable collamer lens(ICL) implantation in 30 eyes of 21 patients with myopic astigmatism more than 2.0 d guided with digital imaging system. data were collected during the first week after phakic IOL ***: Thirty eyes of 21 patients were included in our study. Patients includes 9 males and 12 females. The mean age of the patients was 26.5±7.1(range 21-44)y. The mean preoperative manifest astigmatism was 3.2±1.7(range from 2.25 to 4.75) d. The mean postoperative uncorrected distance visual acuity(UCdVA) were 0.07±0.07(range from 0.1 to 0.0) log MAR. The mean postoperative residual refractive cylinder was 0.25±0.29(range 0-0.75) d. Eyes with postoperative residual refractive cylinder of 0.5 d or less represented 80%(24 eyes). The mean postoperative toric IOL misalignment measured by the OPd scan III was 1.9°±1.45°(range from 0 to 5°). CONCLUSION: Image guided system allows accurate alignment of toric ICL. This is associated with good postoperative visual acuity and low residual refractive astigmatism which correlates with the precision of toric phakic IOL alignment.

关键词： myopic astigmatism toric intraocular lenses image guided system

development of sensing system for 3-dimensional mapping of underground optic fibre cable conduit

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Journal of Control and decision 2022年第3期9卷 265-276页

作者： Min Li sherif Bakr department of Mechanical and Civil Engineering Minnesota State University MankatoMankatoMNUSA

This paper presents a newly designed sensing system for 3-dimensional(3d)mapping of underground optic fibre cable conduit with inertial sensors and *** system consists of a sensing unit containing an inertial measurement unit(IMU)and battery,a duct rodder and a fibre blowing machine with an encoder.A sensor fusion algorithm is developed to estimate the orientation with the measurements of the gyroscope and *** the assumption that the sensing unit only moves along one direction,the 3d trajectory or position of the sensing unit is estimated with the encoder readings and orientation *** information,such as the orientation and position of the starting and ending points,are integrated into the algorithm to correct the sensing drifting and refine the position *** with three different layouts of the conduits are conducted and analysed graphically and numerically by comparing with the actual layouts。

关键词： 3d mapping IMU underground conduit sensor fusion

Hyperspectral imaging and remote trace detection of cis-1,3,4,6-tetranitrooctahydroimidazo-[4,5 d]imidazole(BCHMX)compared with traditional explosives using laser induced fluorescence

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defence Technology（防务技术） 2021年第5期17卷 1609-1616页

作者： Hany S.Ayoub Ashraf F.El-sherif Ahmed Elbeih department of Physics Faculty of ScienceCairo UniversityEgypt Laser Photonics Research Center Engineering Physics DepartmentMilitary Technical CollegeCairoEgypt Explosives department Military Technical CollegeKobry ElkobbahCairoEgypt

cis-1,3,4,6-Tetranitrooctahydroimidazo-[4,5 d]imidazole(BCHMX)is an advanced energetic compound that expected to spread worldwide in the near ***,no approved remote detection methods were reported in current literature for this material,we performed hyper-spectral imaging and laser induced fluorescence(LIF)to a BCHMX sample under low laser fluence for determining the optimum laser wavelength used in any future BCHMX-LIF based remote detection *** this purpose,an experimental setup consisted of a sun spectrum lamp and hyper-spectral camera was built to illuminate and image white powder samples of BCHMX in comparison with the traditional explosives,HMX(1,3,5,7-tetranitro-1,3,5,7-tetraazacyclooctane),RdX(1,3,5-trinitro-1,3,5-triazacyclohexane),PETN(2,2-Bis[(nitroxy)methyl]propane-1,3-diyldinitrate).The imaging reveals strong BCHMX sample absorption contrast among other samples at wavelength ranging from 400 to 410 *** light source was replaced by a 405 nm laser diode illuminator,a strong BCHMX sample LIF at the spectral range from 425 to 700 nm was observed under low laser fluence condition of 0.1 mJ/cm^(2).Finally,we demonstrated successfully the ability of the 405 nm LIF and the hyperspectral imaging technique to detect finger print traces of BCHMX on white cellulose fabric from a distance of 15 m and a detection limit of 1 mg/cm^(2).

关键词： Hyperspectral imaging Remote trace detection BCHMX Laser induced fluorescence

Fault diagnosis in Robot Manipulators Using SVM and KNN

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Intelligent Automation & Soft Computing 2023年第2期35卷 1957-1969页

作者： d.Maincer Y.Benmahamed M.Mansour Mosleh Alharthi sherif S.M.Ghonein Laboratoire de Robotiques Parallélisme et Systèmes Embarquer Département Automatique et ControlUniversitédes Sciences et Technologie Houari BoumedieneAlgiersAlgeria Laboratoire de Recherche en Electrotechnique Ecole Nationale PolytechniqueB.P 182El-Harrach16200AlgiersAlgeria Electrical Engineering department College of EngineeringTaif UniversityP.O.Box 11099Taif21944Saudi Arabia

In this paper,Support Vector Machine(SVM)and K-Nearest Neighbor(KNN)based methods are to be applied on fault diagnosis in a robot manipulator.A comparative study between the two classiﬁers in terms of successfully detecting and isolating the seven classes of sensor faults is considered in this *** both classiﬁers,the torque,the position and the speed of the manipulator have been employed as the input ***,it is to mention that a large database is needed and used for the training and testing *** SVM method used in this paper is based on the Gaussian kernel with the parametersγand the penalty margin parameter“C”,which were adjusted via the PSO algorithm to achieve a maximum accuracy *** were carried out on the model of a Selective Compliance Assembly Robot Arm(SCARA)robot manipulator,and the results showed that the Particle Swarm Optimization(PSO)increased the per-formance of the SVM algorithm with the 96.95%accuracy while the KNN algo-rithm achieved a correlation up to 94.62%.These results showed that the SVM algorithm with PSO was more precise than the KNN algorithm when was used in fault diagnosis on a robot manipulator.

关键词： Support Vector Machine(SVM) Particle Swarm Optimization(PSO) K-Nearest Neighbor(KNN) fault diagnosis manipulator robot(SCARA)

Preparation of solar-enhanced AlZnO@carbon nano-substrates for remediation of textile wastewaters

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Journal of Environmental Sciences 2020年第6期32卷 52-68页

作者： Esraa M.El-Fawal sherif A.Younis Yasser M.Moustafa Philippe Serp Central Laboratories Analysis and Evaluation DepartmentEgyptian Petroleum Research InstituteNasr CityCairo 11727Egypt Laboratoire de Chimie de Coordination(LCC) Unite Propre de Recherche(UPR)Du Centre National de La Recherche Scientifique(CNRS)8241Composante de L’Ecole Nationale D’Ingenieurs en Arts Chimiques et Technologiques(ENSIACET)Universite de ToulouseUniversite Paul Sabatier(UPS)Institut National Polytechnique(INP)-LCC4 Allee Emile Monso31030Toulouse Cedex 4France

Photoactive aluminum doped ZnO(AlZnO)was synthesized by sol-gel *** that,AlZnO photocatalyst was deposited on five carbon-based materials(CBMs)using ultrasonic route followed by solid-state mixing using ball *** CBMs used were poly aniline(PANI),carbon nitride(CN),carbon nanotubes(CNT),graphene(G),and carbon nanofibers(CNF).The crystal phases,elemental compositions,morphological,and optical properties of the AlZnO@CBMs composites were *** results revealed that two of AlZnO@CBMs composites exhibited superior bleaching efficiency(100%removal)and photocatalytic stability(three cycles)for 50μmol/L Methylene Blue(MB)contaminated water after 60 min irradiation in visible light at pH 6.5,0.7%H2O2,and 5 g/L inorganic *** optimum conditions,AlZnO@CBMs nanocomposites were employed for the treatment of mixed dyestuffs composed of MB,Methyl Orange(MO),Astrazone Blue FRR(BB 69),and Rhodamine B(RhB)dyes under dark,ultraviolet,visible,and direct *** mixed dyestuffs,the AlZnO@G achieved the highest dye sorption capacity(60.91μmol dye stuffs/g)with kinetic rate 8.22×10^-3 min^-1 in 90 min via multi-layer physisorption(Freundlich isotherm)on graphene *** additions,AlZnO@CN offered the highest photo-kinetic rate(Kphoto)of^54.1×10^-3 min^-1(93.8%after 60 min)under direct ***,the selective radical trapping experiment confirmed that the holes and oxidative superoxide radicals are crucial on dyes photodegradation *** to their superior performance,AlZnO@G and AlZnO@CN nanocomposites can offer an effective in-situ solar-assisted adsorption/photocatalytic remediation of textile wastewater effluents.

关键词： Carbon nanomaterials AlZnO photocatalyst Hybrid adsorption/photo-catalysis Kinetic and isotherm modeling Textile wastewater remediation

ANN approaches to determine the dielectric strength improvement of MgO based low density polyethylene nanocomposite

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Journal of Advanced dielectrics 2021年第4期11卷 27-36页

作者： sherif Haggag Loai Nasrat Hanafy Ismail Faculty of Engineering Department of Power and Machines Ain Shams UniversityCairoEgypt Faculty of Engineering department of Electrical Engineering Aswan University AswanEgypt

This paper presents the modification occurred to the dielectric strength feature of low density polyethylene compounded with nano magnesia(LdPE/MgO).MgO nanoparticles were prepared using sol-gel technique,MgO filler surface was functionalized to improve the interfacial ***’s groups of composites with different filler concentrations were fabricated by mix blend *** exposed to various salinity media by immersion,dielectric strength test was applied on each set according to relevant ASTM standard with identical testing *** results were statistically processed then compared to the pristine *** results utilized to learn Artificial Neural Network in order to acquire the value of dielectric strength of compounds having similar composition but containing different doping amounts or influenced with various salinity level *** dielectric strength is enhanced by the addition of MgO *** the investigation of the obtained results,it is concluded that additives of 1.4%filler concentration by weight is the optimum MgO content for LdPE/MgO nanofiller *** think that this paper may promote a good researching methodology that gather both empirical work and numerical tools in this field.

关键词： Polymer nanocomposites salinity surface treatment breakdown strength artificial neural network

Anisotropic alignments of hierarchical Li2SiO3/TiO2@nano-C anode//LiMnPO4@nano-C cathode architectures for full-cell lithium-ion battery

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National Science Review 2020年第5期7卷 863-880页

作者： Hesham Khalifa sherif A. El-Safty Abdullah Reda Mohamed A. Shenashen Alaa I.Eid Research Center for Functional Materials National Institute for Materials Science department of Petrochemical Egyptian Petroleum Research Institute Composite Lab Advanced Materials Division Central Metallurgical R&D Institute

We report on low-cost fabrication and high-energy density of full-cell lithium-ion battery (LIB) ***-hierarchical electrode architectures of Li2SiO3/TiO2@nano-carbon anode (***@nano-C) and high-voltage olivine LiMnPO4@nano-carbon cathode (LMPO@nano-C) are designed for half-and full-system LIB-CR2032 coin cell *** the basis of primary architecture-power-driven LIB geometrics,the structure keys including three-dimensional (3d) modeling superhierarchy,multiscale micro/nano architectures and anisotropic surface heterogeneity affect the buildup design of anode/cathode LIB *** hierarchical electrode surface topologies enable continuous in-/out-flow rates and fast transport pathways of Li+-ions during charge/discharge *** stacked layer configurations of pouch LIB-types lead to excellent charge/discharge rate,and energy density of237.6 Wh *** the most promising LIB-configurations,the high specific energy density of hierarchical pouch battery systems may improve energy storage for long-driving range of electric ***,the anisotropic alignments of hierarchical electrode architectures in the large-scale LIBs provide proof of excellent capacity storage and outstanding durability and *** full-system LIB-CR2032 coin cell models maintain high specific capacity of～89.8%within a long-term life period of2000 cycles,and average Coulombic efficiency of99.8%at 1C rate for future configuration of LIB manufacturing and commercialization challenges.

关键词： lithium-ion batteries micro/nano architectures LiMnPO4@nano-carbon cathode Li2SiO3/TiO2@nano-carbon anode LIB-CR2032 coin cell models