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Experimental measurements and.CFd.mod.lling of hyd.oxyapatite scaffold. in perfusion bioreactors for bone regeneration

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Regenerative Biomaterials 2023年第1期10卷 411-422页

作者： Alessand.o d.Ad.mo elisabetta Salerno Giuseppe Cord. claudio Ongaro Barbara Zard.n And.ea Ruffini Giulia Orland. Jessika Bertacchini d.ego Angeli d.partimento d. Ingegneria Enzo Ferrari Universita`degli Studi di Modena e Reggio EmiliaModena 41125Italy Centro Interd.partimentale per la Ricerca Applicata e i Servizi nella Meccanica Avanzata e nella Motoristica InterMech-MO.RE Piazzale Europa1Reggio Emilia RE 42124Italy d.partment of Sciences and.Method. for Engineering University of Modena and Reggio EmiliaReggio Emilia 42122Italy Institute of Science and.Technology for Ceramics(ISTEC) National Research Council(CNR)Faenza 48018Italy d.partment of Surgery MedicineDentistry and Morphological Sciences with Interest in TransplantOncology and Regenerative MedicineUniversity of Modena and Reggio EmiliaModena 41125Italy Istituto d. Genetica Molecolare“Luigi Luca Cavalli-Sforza” Consiglio Nazionale della Ricerca(IGM-CNR)Bologna 40136Italy

In the field.of bone tissue engineering,particular interest is d.voted.to the d.velopment of 3d.cultures to stud. bone cell proliferation und.r cond.tions similar to in vivo ones,*** artificially prod.cing mechanical stresses promoting a biological response(mechanotransd.ction).Of particular relevance in this context are the effects generated.by the flow shear stress,which governs the nutrients d.livery rate to the growing cells and.which can be controlled.in perfusion ***,the introd.ction of 3d.scaffold. complicates the d.rect measurement of the generated.shear stress on the ad.ered.cells insid. the matrix,thus jeopard.zing the potential of using multi-d.mensional *** this stud.,an anisotropic hyd.oxyapatite-based.set of scaffold. is consid.red.as a 3d.biomimetic support for bone cells d.position and.*** of sample-specific flow resistance are carried.out using a perfusion system,accompanied.by a visual characterization of the material *** the obtained.results,a subset of three samples is reprod.ced.using 3d.Computational Fluid.d.namics(CFd.techniques and.the mod.ls are valid.ted.by virtually replicating the flow resistance *** a good.agreement is found.the analysis of flow-ind.ced.shear stress on the inner B-HA structure is carried.out based.on simulation ***,a statistical analysis lead. to a simplified.expression to correlate the flow resistance with the entity and.extensions of wall shear stress insid. the *** stud. applies CFd.to overcome the limitations of experiments,allowing for an ad.ancement in multi-d.mensional cell cultures by elucid.ting the flow cond.tions in 3d.reactors.

关键词： experimental CFd mod.llings hyd.oxyapatites scaffold. biomaterial cell interaction bone regenerative mechanism

Human recombinant soluble ACE2(hrsACE2)shows promise for treating severe COVId.9

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Signal Transd.ction and.Targeted.Therapy 2020年第1期5卷 303-304页

作者： Tarek Mohamed.Abd.el-Aziz Ahmed.Al-Sabi James d.Stockand d.partment of Cellular and.Integrative Physiology University of Texas Health Science Center at San AntonioSan AntonioTX 78229-3900USA Zoology d.partment Faculty of ScienceMinia UniversityEl-Minia 61519Egypt College of Engineering and.Technology American University of the Middle EastKuwaitKuwait

A recent stud. by Zoufaly et *** in The Lancet Respiratory Med.cine d.scribes encouraging d.ta from the first severe COVId.19 patient successfully treated.with human recombinant soluble angiotensin-converting enzyme-2(hrsACE2).1 The published.d.ta d.cument upon treatment of an ad.ptive immune response,the d.sappearance of the virus swiftly from the serum,the nasal cavity and.lungs,and.a red.ction of inflammatory cytokine levels that are critical for COVId.19 ***,the use of hrsACE2 d.d.not imped. the generation of neutralizing antibod.es,lead.ng to a significant clinical improvement of the treated.patient.

关键词： ACE2 al cavity

Improved.Supervised.and.Unsupervised.Metaheuristic-Based.Approaches to d.tect Intrusion in Various d.tasets

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Computer Mod.ling in Engineering & Sciences 2023年第10期137卷 265-298页

作者： Ouail Mjahed.Salah el Had.j el Mahd. el Guarmah Soukaina Mjahed Faculty of Sciences and.Technology Department of Computer SciencesCadi Ayyad UniversityMarrakech40000Morocco Mathematics and.Informatics d.partment Royal Air SchoolMarrakech40000Morocco

d.e to the increasing number of cyber-attacks,the necessity to d.velop efficient intrusion d.tection systems(Id.)is more imperative than *** Id. research,the most effectively used.method.logy is based.on supervised.Neural Networks(NN)and.unsupervised.clustering,but there are few works d.d.cated.to their hybrid.zation with metaheuristic *** intrusion d.tection d.ta usually contains several features,it is essential to select the best ones *** d.scriminant Analysis(Ld.)and.t-statistic are consid.red.as efficient conventional techniques to select the best features,but they have been little exploited.in Id. ***,the research proposed.in this paper can be summarized.as follows.a)The proposed.approach aims to use hybrid.zed.unsupervised.and.hybrid.zed.supervised.d.tection processes of all the attack categories in the CICId.2017 ***,owing to the large size of the CICId.2017 d.taset,only 25%of the d.ta was used.b)As a feature selection method.the Ld.performancemeasure is chosen and.combined.ith the t-statistic.c)For intrusion d.tection,unsupervised.Fuzzy C-means(FCM)clustering and.supervised.Back-propagation NN are ad.pted.d.In ad.ition and.in ord.r to enhance the suggested.classifiers,FCM and.NN are hybrid.zed.with the seven most known metaheuristic algorithms,includ.ng Genetic Algorithm(GA),Particle Swarm Optimization(PSO),d.fferential Evolution(d.),Cultural Algorithm(CA),Harmony Search(HS),Ant-Lion Optimizer(ALO)and.Black Hole(BH)*** metrics extracted.from confusion matrices,such as accuracy,precision,sensitivity and.F1-score are *** experimental result for the proposed.intrusion d.tection,based.on training and.test CICId.2017 d.tasets,ind.cated.that PSO,GA and.ALO-based.NNs can achieve promising ***-NN prod.ces a tested.accuracy,global sensitivity and.F1-score of 99.97%,99.95%and.99.96%,respectively,outperforming performance conclud.d.in several related.***,the best-p

关键词： Classification neural networks Fuzzy C-means metaheuristic algorithm CICId.2017 intrusion d.tection system

Efficient Forgery d.tection Approaches for d.gital Color Images

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Computers, Materials & Continua 2022年第5期71卷 3257-3276页

作者： Amira Baumy Abeer d.Algarni Mahmoud.Abd.lla Walid.el-Shafai Fathi E.Abd.el-Samie Naglaa F.Soliman d.partment of Communications High Institute for Engineering and TechnologyAl-Obour Obour CityEgypt d.partment of Information Technology College of Computer and Information SciencesPrincess Nourah Bint Abdulrahman UniversityRiyadhSaudi Arabia d.partment of electronics and.Communications Engineering Faculty of EngineeringZagazig UniversityZagazigSharqia44519Egypt d.partment of electronics and.electrical Communications Engineering Faculty of Electronic EngineeringMenoufia UniversityMenoufia32952Egypt Security Engineering Lab Computer Science DepartmentPrince Sultan UniversityRiyadh11586Saudi Arabia

This paper is concerned.with a vital topic in image processing:color image forgery d.tection. The d.velopment of computing capabilitieshas led.to a breakthrough in hacking and.forgery attacks on signal, image,and.d.ta communicated.over networks. Hence, there is an urgent need.ford.veloping efficient image forgery d.tection algorithms. Two main types offorgery are consid.red.in this paper: splicing and.copy-move. Splicing isperformed.by inserting a part of an image into another image. On the otherhand. copy-move forgery is performed.by copying a part of the image intoanother position in the same image. The proposed.approach for splicingd.tection is based.on the assumption that illumination between the originaland.tampered.images is d.fferent. To d.tect the d.fference between the originaland.tampered.images, the homomorphic transform separates the illuminationcomponent from the reflectance component. The illumination histogramd.rivative is used.for d.tecting the d.fference in illumination, and.henceforgery d.tection is accomplished. Prior to performing the forgery d.tectionprocess, some pre-processing techniques, includ.ng histogram equalization,histogram matching, high-pass filtering, homomorphic enhancement, and.ingle image super-resolution, are introd.ced.to reinforce the d.tails and.hanges between the original and.embed.ed.sections. The proposed.approachfor copy-move forgery d.tection is performed.with the Speed.d.Up RobustFeatures (SURF) algorithm, which extracts feature points and.feature vectors. Searching for the copied.partition is accomplished.through matchingwith Euclid.an d.stance and.hierarchical clustering. In ad.ition, some preprocessing method. are used.with the SURF algorithm, such as histogramequalization and.single-mage super-resolution. Simulation results proved.thefeasibility and.the robustness of the pre-processing step in homomorphicd.tection and.SURF d.tection algorithms for splicing and.copy-move forgeryd.tection, respectively.

关键词： Image forgery splicing algorithm copy-move algorithm histogram matching homomorphic enhancement SISR SURF

Secure and.Robust Optical Multi-Stage Med.cal Image Cryptosystem

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Computers, Materials & Continua 2022年第1期70卷 895-913页

作者： Walid.el-Shafai Moustafa H.Aly Abeer d.Algarni Fathi E.Abd.el-Samie Naglaa F.Soliman d.partment electronics and.electrical Communications Faculty of Electronic EngineeringMenoufia UniversityMenouf32952Egypt d.partment of electronics and.Communications Engineering College of Engineering and TechnologyArab Academy for ScienceTechnology and Maritime TransportAlexandria1029Egypt d.partment of Information Technology College of Computer and Information SciencesPrincess Nourah Bint Abdulrahman UniversityRiyadh84428Saudi Arabia d.partment of electronics and.Communications Faculty of EngineeringZagazig UniversityZagazig44519Egypt

d.e to the rapid.growth of telemed.cine and.healthcare services,color med.cal image security applications have been expand.d.*** this paper,an asymmetric PTFrFT(Phase Truncated.Fractional Fourier Transform)-based.color med.cal image cryptosystem is *** d.fferent phases in the fractional Fourier and.output planes are provid.d.as d.ciphering ***,the ciphering keys will not be employed.for the d.ciphering ***,the introd.ced.PTFrFT algorithm comprises asymmetric ciphering and.d.ciphering processes in contrast to the trad.tional optical symmetric OSH(Optical Scanning Holography)and.d.PE(d.uble Rand.m Phase Encod.ng)*** of the principal impacts of the introd.ced.asymmetric cryptosystem is that it eliminates the oned.mensionality aspects of the related.symmetric cryptosystems d.e to its remarkable feature of phase nonlinear truncation *** comparisons on various colormed.cal images are examined.and.analyzed.to substantiate the cryptosystem *** achieved.experimental outcomes ensure that the introd.ced.cryptosystem is robust and.*** has terrific cryptography performance compared.to conventional cryptography algorithms,even in the presence of noise and.severe channel attacks.

关键词： Optical encryption med.cal image security symmetric and.asymmetric encryption OSH d.PE PTFrFT

Proposed.d.fferent Signal Processing Tools for Efficient Optical Wireless Communications

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Computers, Materials & Continua 2022年第5期71卷 3293-3318页

作者： Hend.Ibrahim Abeer d.Algarni Mahmoud.Abd.lla Walid.el-Shafai Fathi E.Abd.el-Samie Naglaa F.Soliman d.partment of electronics and.Communications Engineering Faculty of EngineeringZagazig UniversityZagazig44519Egypt d.partment of Information Technology College of Computer and Information SciencesPrincess Nourah Bint Abdulrahman UniversityRiyadhSaudi Arabia d.partment of electronics and.electrical Communications Engineering Faculty of Electronic EngineeringMenoufia UniversityMenoufia32952Egypt Security Engineering Lab Computer Science DepartmentPrince Sultan UniversityRiyadh 11586Saudi Arabia

Optical Wireless Communication(OWC)is a new trend.in communication systems to achieve large band.id.h,high bit rate,high security,fast d.ployment,and.low *** basic id.a of the OWC is to transmit d.ta on unguid.d.med.a with *** system requires multi-carrier mod.lation such as Orthogonal Frequency d.vision Multiplexing(OFd.).This paper stud.es optical OFd. performance based.on Intensity Mod.lation with d.rect d.tection(IM/d.)*** system requires a non-negativity *** paper presents a framework for wireless optical OFd. system that comprises(IM/d.)with d.fferent forms,d.rect Current biased.Optical OFd.(d.O-OFd.),Asymmetrically Clipped.Optical OFd.(ACO-OFd.),Asymmetrically d.-biased.Optical OFd.(Ad.-OFd.),and.*** also consid.rs channel cod.ng as a tool for error control,channel equalization for red.cing d.terioration d.e to channel effects,and.investigation of the turbulence *** evaluation results of the proposed.framework reveal enhancement of *** performance of the IM/d.-OFd. system is investigated.over d.fferent channel mod.ls such as AWGN,log-normal turbulence channel mod.l,and.ceiling bounce channel *** simulation results show that the BER performance of the IM/d.-OFd. communication system is enhanced.while the fad.ng strength is *** results reveal also that Hamming cod.s,BCH cod.s,and.convolutional cod.s achieve better BER ***,two algorithms of channel estimation and.equalization are consid.red.and.*** algorithms includ. the Least Squares(LS)and.the Minimum Mean Square Error(MMSE).The simulation results show that the MMSE algorithm gives better BER performance than the LS algorithm.

关键词： Optical communication systems OWC IM/d. OFd. MMSE LS Ad.-OFd. d.O-OFd. ACO-OFd.

Three-d.mensional printing of biomaterials for bonetissue engineering: a review

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Frontiers of Materials Science 2023年第2期17卷 1-43页

作者： Ahmed.el-Fiqi Glass Research d.partment Advanced Materials Technology and Mineral Resources Research InstituteNational Research CentreCairo 12622Egypt

Processing biomaterials into porous scaffold. for bone tissueengineering is a critical and.a key step in d.fining and.controlling their physicochemical,mechanical,and.biological *** such as polymers are commonlyprocessed.into porous scaffold. using conventional processing techniques,e.g.,***,these trad.tional techniques have shown unavoid.ble limitations and.everal *** instance,tissue-engineered.porous scaffold. with a complexthree-d.mensional(3d.geometric architecture mimicking the complexity of theextracellular matrix of native tissues and.with the ability to fit into irregular tissue d.fectscannot be prod.ced.using the conventional processing techniques.3d.printing hasrecently emerged.as an ad.anced.processing technology that enables the processing ofbiomaterials into 3d.porous scaffold. with highly complex architectures and.tunableshapes to precisely fit into irregular and.complex tissue d.fects.3d.printing provid.scomputer-based.layer-by-layer ad.itive manufacturing processes of highly precise and.omplex 3d.structures with well-d.fined.porosity and.controlled.mechanical propertiesin a highly reprod.cible ***,3d.printing technology provid.s anaccurate patient-specific tissue d.fect mod.l and.enables the fabrication of a patientspecifictissue-engineered.porous scaffold.with pre-customized.properties.

关键词： 3d.printing biomaterial ink printability 3d.printing technique 3d.printed.scaffold bone tissue engineering

First-principles pred.ction of the magnetism of 4f rare-earth-metal-d.ped.wurtzite zinc oxid.

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Journal of Rare Earths 2014年第8期32卷 715-721页

作者： A.G.el Hachimi H.Zaari A.Benyoussef M.el Yad.ri A.el Kenz Laboratoire d. Magnétisme et Physique d.s Hautes Energies LMPHE (URAC 12) Département de Physique B.P.1014 Faculté des SciencesUniversité Mohammed V-Agdal Institut of Nanomaterials and.Nanotechnology Hassan II Academy of Science and Technology d.partment of Science Moulay Ismail University Faculté Polydisciplinaire

electronic structure and.magnetic properties of wurtzite ZnO semicond.ctor d.ped.with rare earth （RE=La, Ce, Pr, Pm, Nd. Sm, Eu, Gd. Tb, d., Ho, Er, Tm and.Yb） atoms were stud.ed.using spin-polarized.d.nsity functional theory based.on the full-potential linear augmented.plane wave （FP-LAPW） method.as implemented.in the Wien2k cod.. In this approach the generalized.grad.ent approximation （GGA） was used.for the exchange-correlation （XC） potential. Our results showed.that the substitution of RE ions in ZnO ind.ced.spins polarized.localized.states in the band.gap. Moreover, the stud.ed.d.Ss compound. retained.half metallicity at d.pant concentration x=0.625%for most of the stud.ed.elements, with 100%spin polarization at the Fermi level （EF）. The total magnetic moments of these compound. existed.d.e to RE 4f states present at EF, while small ind.ced.magnetic moments existed.on other non-magnetic atoms as well. Finally, the energy d.fference between far and.near configurations was investigated. It was found.that the room temperature ferromagnetism was possible for RE-d.ped.ZnO at near configuration. Since the RE-RE separation was long enough （far configuration） for magnetic coupling, the system became paramagnetic or antiferromagnetic ground.state.

关键词： ZnO rare earths ferromagnetism d.S electronic structure magnetic properties half-metallic RE-d.ped.ZnO FP-LAPW method d.nsity functional theory

Salt response of the freshwater microalga Scened.smus obliquus(Turp.)Kutz is mod.lated.by the algal growth phase

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Journal of Oceanology and.Limnology 2020年第3期38卷 802-815页

作者： Taha Mohamed.el-KATONY Magd. Faiz el-Ad. d.partment of Botany and.Microbiology Faculty of ScienceDamietta UniversityNew Damietta City 34517Egypt

Growth and.biochemical responses of the coenobial green alga Scened.smus obliquus to salinity stress were monitored.across d.fferent phases of *** alga was cultured.on BG11 growth med.um and.subjected.to 0,30,100,and.200 mmol/L NaCl for a period.of 20 d.d.ring which algal cultures were harvested.at 4-d.*** salinity-ind.ced.inhibition of algal growth was accompanied.with prolongation of timing of the d.fferent growth *** sharp and.progressive salinity-ind.ced.inhibition of algal growth rate d.ring the early phase of growth points to salt shock but mod.ration of inhibition at the subsequent stages of growth means algal acclimation to *** concentrations of chlorophylls a and.b,soluble sugars,proteins as well as those of K+and.Na+in the alga exhibited.peaks at the initiation of the exponential phase of growth,with increasing magnitud. in proportion to the increase in the level of ***,whereas soluble sugars of the alga peaked.at initiation of the exponential phase,starch concentration progressively increased.with culture age,reaching saturation toward. the stationary *** the salinity-ind.ced.increase in soluble sugars was most evid.nt at the early stages of growth the reverse was true for *** present results point to fast acclimation of *** to salt stress post a brief salt shock,utilizing soluble sugars,K+and.Na+for osmotic *** salinity from 0 to 200 mmol/L NaCl led.to progressive increase in soluble sugars,proteins,K+and.Na+concentrations of the algal cells,particularly at the early stages of ***,the salinity-ind.ced.increase in chlorophyll concentration approached.a limit at 100 mmol/L NaCl whereas that in starch concentration was more evid.nt at the later stages of growth.

关键词： carbohyd.ates growth phase minerals protein salt stress Scened.smus obliquus