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Decoding molecular mechanisms:brain aging and Alzheimer's disease

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Neural Regeneration Research 2025年第8期20卷 2279-2299页

作者： Mahnoor Hayat Rafay Ali Syed Hammad Qaiser Mohammad Uzair khalid Al-Regaiey Roaa Khallaf Lubna Abdullah Mohammed Albassam Imdad Kaleem Xueyi Wang Ran Wang Mehwish SBhatti Shahid Bashir Atta-ur-Rahman School of Applied Biosciences(ASAB) National University of Sciences and Technology(NUST)IslamabadPakistan Department of Biotechnology Quaid-i-Azam UniversityIslamabadPakistan Department of Biological Sciences Faculty of Basic&Applied SciencesInternational Islamic University Islamabad(IIUI)IslamabadPakistan Department of Bioengineering King Fahd University of Petroleum and MineralsDhahranSaudi Arabia Department of Physiology College of MedicineKing Saud UniversityRiyadhSaudi Arabia Department of Neurology Neuroscience CenterKing Fahad Specialist HospitalDammamSaudi Arabia Department of Mental Health Neuroscience CenterKing Fahad Specialist HospitalDammamSaudi Arabia Department of Biosciences Commission on Science and Technology for Sustainable Development in the South(COMSATS University)IslamabadPakistan Department of Psychiatry The First Hospital of Hebei Medical UniversityShijiazhuangHebei ProvinceChina Mental Health Institute of Hebei Medical University ShijiazhuangHebei ProvinceChina Department of Neurobiology and Behavior University of CaliforniaIrvineCAUSA Neuroscience Center King Fahad Specialist Hospital DammamDammamSaudi Arabia

The complex morphological,anatomical,physiological,and chemical mechanisms within the aging brain have been the hot topic of research for *** aging process alters the brain structure that affects functions and cognitions,but the worsening of such processes contributes to the pathogenesis of neurodegenerative disorders,such as Alzheimer's *** these observable,mild morphological shifts,significant functional modifications in neurotransmission and neuronal activity critically influence the aging *** these changes is important for maintaining cognitive health,especially given the increasing prevalence of age-related conditions that affect *** review aims to explore the age-induced changes in brain plasticity and molecular processes,differentiating normal aging from the pathogenesis of Alzheimer's disease,thereby providing insights into predicting the risk of dementia,particularly Alzheimer's disease.

关键词： Alzheimer’s disease brain aging cognitive health dementia molecular mechanisms neuronal activity neuroplasticity neurotransmission

Application of maximum rank distance codes in designing of STBC-OFDM system for next-generation wireless communications

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Digital Communications and Networks 2024年第4期10卷 1048-1056页

作者： Arslan khalid Prapun Suksompong School of Information Computer and Communication TechnologySirindhorn International Institute of TechnologyThammasat UniversityPathumthani12000Thailand

Space-Time Block Coded(STBC)Orthogonal Frequency Division Multiplexing(OFDM)satisfies higher data-rate requirements while maintaining signal quality in a multipath fading ***,conventional STBCs,including Orthogonal STBCs(OSTBCs),Non-Orthogonal(NOSTBCs),and Quasi-Orthogonal STBCs(QOSTBCs),do not provide both maximal diversity order and unity code rate simultaneously for more than two transmit *** paper targets this problem and applies Maximum Rank Distance(MRD)codes in designing STBCOFDM *** following the direct-matrix construction method,we can construct binary extended finite field MRD-STBCs for any number of transmitting *** uses MRD-STBCs built over Phase-Shift Keying(PSK)modulation to develop an MRD-based STBC-OFDM *** MRD-based STBC-OFDM system sacrifices minor error performance compared to traditional OSTBC-OFDM but shows improved results against NOSTBC and *** also provides 25%higher data-rates than OSTBC-OFDM in configurations that use more than two transmit *** tradeoffs are minor increases in computational complexity and processing delays.

关键词： Bit error rate(BER) Galois field Maximum rank distance(MRD)codes Orthogonal frequency division multiplexing (OFDM) Primitive polynomials Space-time block codes(STBC)

Application of Hilbert's Projective Metric on Symmetric Cones

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Acta Mathematica Sinica,English Series 2006年第5期22卷 1467-1472页

作者： khalid KOUFANY Institut Elie Cartan UMR 7502(UHP-CNRS-INRIA)Université Henri Poincaré(Nancy 1)B.P.239F-54506 Vandoeuvre-lès-Nancy CedexFrance

Let Ω be a symmetric cone. In this note, we introduce Hilbert＇s projective metric on Ω in terms of Jordan algebras and we apply it to prove that, given a linear invertible transformation g such that g（Ω） = Ω an... 详细信息

关键词： Hilbert's projective metric Symmetric cone

Numerical simulation of compression corner flows at Mach number 9

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Chinese Journal of Aeronautics 2020年第6期33卷 1611-1624页

作者： Amjad APASHA khalid AJUHANY Department of Aerospace Engineering King Abdulaziz UniversityJeddah 21589Saudi Arabia

A hypersonic vehicle encounters a wide range of conditions during its complete flight *** flight conditions may vary from low to high Mach numbers with varying angles of *** near-wall viscous dissipation associated with flows at combined high Mach and Reynolds numbers leads to significant wall heat transfer rates and shear *** shock wave/boundary-layer interaction results in a flow separation region,which commonly augments total pressure losses in the flow and lowers the efficiency of aerodynamic control surfaces such as fins installed on a *** standard turbulence models,when used to resolve such flows,result in incorrect separation bubble size for large separated ***,it results in an inaccurate aerodynamic load,such as the wall pressures,skin friction distribution,and heat transfer *** previous studies,the application of the shock-unsteadiness correction to the standard two-equation k-ωturbulence model improved the separation bubble size leading to an accurate pressure prediction and shock definition with the assumption of constant Prandtl *** the present work,the new shock-unsteadiness modification to the k-ωturbulence model is applied to the hypersonic compression corner *** new model with variable Prandtl number is based on the model parameter,which depends upon the local density *** computed wall pressures,heat flux and flow field are compared to the experimental data.A parametric study is carried out by varying compression deflection angles,free stream Reynolds number and wall temperatures to compute the flow field and wall data accurately,particularly in the shock boundary layer interaction *** new shockunsteadiness modified k-ωmodel with variable Prandtl number shows an accurate prediction of initial pressure rise location,pressure distribution in the plateau region and heat flux in comparison to the standard k-ωmodel.

关键词： Boundary layer Expansion fan Heat transfer Hypersonic flows Separation length Shock-unsteadiness model Shock wave Turbulence model Turbulent Prandtl number

Numerical and experimental study of wave shaper effects on detonation wave front

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Defence Technology（防务技术） 2018年第1期14卷 45-50页

作者： khalid Naeem Arshad Hussain SCME (NUST) Islamabad Simulation Lab.Room 113 SCME NUST H-12 Campus SCME (NUST) H-12 Campus

In the current study, streak camera was used to find concentricity of the assembly during detonation,investigate and compare shock front within the high explosive and behavior of the shock front on the surface of the liner, one containing wave shaper and the other without wave shaper. Streaks revealed that the whole assembly was concentric till the formation of the jet. Observed streaks vindicate the uniform propagation of shock front in both the cases. Results obtained for shock front velocities are in agreement with those obtained from simulations. In the presence of wave shaper higher shock front velocity was observed both in simulation and experiment. Simulation without wave-shaper showed that shock front struck the copper cone at grazing angle while in the presence of wave-shaper it struck at an angle of 125.

关键词： Shock front Streak camera Simulation Wave shaper

Assessment of the properties of polycrystalline rock salt synthesized under nominally dry and wet conditions

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Journal of Rock Mechanics and Geotechnical Engineering 2021年第2期13卷 311-320页

作者： Amirsalar Moslehy khalid Alshibli Department of Civil and Environmental Engineering University of TennesseeKnoxvilleTN37996USA

Polycrystalline rock salt’s compression is a function of applied stresses,exposure duration to the applied stresses,ambient temperature,and water *** salt’s compressional behavior under different conditions and its effects on the specimens’mechanical properties have been investigated in the ***,the one-dimensional(1D)compression behavior of polycrystalline rock salt at various water contents and how the specimen’s compression at different water contents further affects its physical and mechanical properties are not fully understood *** this study,polycrystalline rock salt specimens were prepared under nominally dry and wet conditions and some of the dry and wet specimens were annealed after the *** relationship between the porosity of the specimens and the logarithm of the applied axial stresses during the 1D compression was found to follow a linear relationship after reaching unique critical porosities of 32%and 37%for the dry and wet specimens,*** and reloading the specimens did not result in any major changes in the porosity of the *** specimens compressed under wet condition showed an average final porosity of 2.6%compared to 6.9%for the dry *** dry and wet specimens that were annealed after the compression exhibited a lower porosity in comparison to the dry and wet specimens,*** compression experiments on the specimens showed dry and wet specimens possess averaged unconfined compressive strengths(σ_(u))of 64.3 and 16.2 MPa,*** decreased σ_(u)of the dry specimens to 39.6 MPa and increased σ_(u)of the wet specimens to 41 MPa.

关键词： Halite Rock salt Unconfined compression One-dimensional(1D)compression

Observability by using viability kernels

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控制理论与应用（英文版） 2012年第3期10卷 303-308页

作者： khalid KASSARA Systems and Control Group University Hassan ⅡCasablanca 20100Morocco

The aim of this paper is to propose a new way to deal with observability of systems governed by ODEs, in a more general setting than the standard output equation. The primary finding is that observability over a time horizon reduces to single-valuedness of the vertical section of a set we name the observability kernel. The latter consists of the viability kernel of the output domain under the augmented system. The approach may be used either for global or local observability, to which available results on single-valuedness of multifunctions shall be applied in order to get necessary and/or sufficient characterizing conditions. Several examples are provided in order to illustrate the method.

关键词： Observability Viability kernel Single-valuedness Lower semicontinuity Monotone multifunctions

Modulating microRNAs in cancer: next-generation therapies

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Cancer Biology & Medicine 2022年第3期19卷 289-304页

作者： Nahid Arghiani khalid Shah Center for Stem Cell and Translational Immunotherapy(CSTI) Harvard Medical SchoolBostonMA 02115USA Department of Neurosurgery Brigham and Women’s HospitalHarvard Medical SchoolBostonMA 02115USA Harvard Stem Cell Institute Harvard UniversityCambridgeMA 02138USA

MicroRNAs(miRNAs)are a class of endogenously expressed non-coding regulators of the genome with an ability to mediate a variety of biological and pathological *** is growing evidence demonstrating frequent dysregulation of microRNAs in cancer cells,which is associated with tumor initiation,development,migration,invasion,resisting cell death,and drug *** have shown that modulation of these small RNAs is a novel and promising therapeutic tool in the treatment of a variety of diseases,especially cancer,due to their broad influence on multiple cellular ***,suboptimal delivery of the appropriate miRNA to the cancer sites,quick degradation by nucleases in the blood circulation,and off target effects have limited their research and clinical ***,there is a pressing need to improve the therapeutic efficacy of miRNA modulators,while at the same time reducing their *** delivery vehicles for miRNA modulators have been shown to be effective in vitro and in *** this review,we will discuss the role and importance of miRNAs in cancer and provide perspectives on currently available carriers for miRNA *** will also summarize the challenges and prospects for the clinical translation of miRNAbased therapeutic strategies.

关键词： MiRNAs dysregulation delivery systems cancer therapy clinical translation

Analytical Investigation of Soliton Solutions to Three Quantum Zakharov-Kuznetsov Equations

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Communications in Theoretical Physics 2018年第10期70卷 405-412页

作者： Rahmatullah Ibrahim Nuruddeen khalid Suliman Aboodh khalid K. Ali Department of Mathematics Federal University Dutse Department of Mathematics Faculty of Science & Technology Omdurman Islamic University Department of Mathematics Faculty of Science & Arts University of Bisha Mathematics Department Faculty of Science Al-Azhar University

In the present paper, the two-dimensional quantum Zakharov-Kuznetsov(QZK) equation, three-dimensional quantum Zakharov-Kuznetsov equation and the three-dimensional modified quantum Zakharov-Kuznetsov equation are analytically investigated for exact solutions using the modified extended tanh-expansion based method. A variety of new and important soliton solutions are obtained including the dark soliton solution, singular soliton solution, combined dark-singular soliton solution and many other trigonometric function solutions. The used method is implemented on the Mathematica software for the computations as well as the graphical illustrations.

关键词： two-dimensional QZK equation three-dimensional QZK equations soliton solutions