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Some exact solutions of the oscillatory motion of a generalized second grade fluid in an annular region of two cylinders

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Acta Mechanica Sinica 2010年第4期26卷 541-550页

作者： A.Mahmood C.Fetecau n.a.khan M.Jamil Department of Mathematics COMSATS Institute of Information Technology Department of Mathematics Technical University of Iasi Department of Mathematics University of Karachi Abdus Salam School of Mathematical Sciences GC University

The velocity field and the associated shear stress corresponding to the longitudinal oscillatory flow of a generalized second grade fluid, between two infinite coaxial circular cylinders, are determined by means of the Laplace and Hankel transforms. Initially, the fluid and cylinders are at rest and at t = 0＋ both cylinders suddenly begin to oscillate along their common axis with simple harmonic motions having angular frequencies Ω1 and Ω2. The solutions that have been obtained are presented under integral and series forms in terms of the generalized G and R functions and satisfy the governing differential equation and all imposed initial and boundary conditions. The respective solutions for the motion between the cylinders, when one of them is at rest, can be obtained from our general solutions. Furthermore, the corresponding solutions for the similar flow of ordinary second grade fluid and newtonian fluid are also obtained as limiting cases of our general solutions. At the end, the effect of different parameters on the flow of ordinary second grade and generalized second grade fluid are investigated graphically by plotting velocity profiles.

关键词： Generalized second grade fluid Velocity field Shear stress Longitudinal oscillatory flow Laplace and Hankel transforms

Flow of micropolar fluid over an off centered rotating disk with modified Darcy's law

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Propulsion and Power Research 2017年第4期6卷 285-295页

作者： n.a.khan S.khana A.Ara Department of Mathematics University of KarachiKarachiSindh 75270Pakistan Department of Computer Science Mohammad Ali Jinnah UniversityKarachiSindh 75400Pakistan

The problem of the steady, incompressible, three dimensional stagnation point flow of a micropolar fluid over an off centered infinite rotating disk in a porous medium is studied in this article. Injection/suction is applied uniformly throughout the surface of porous disk. The Darcy's resistance for the micropolar fluid is also formulated. The partial differential equations are converted into the set of ordinary differential equation by utilizing the suitable transformation. The system of equations is analytically solved by the means of a non-perturbative technique, homotopy analysis method (HAM). The influence of rotational parameter, material parameter, spin gradient viscosity parameter, micro-inertia density parameter, porosity parameter and suction/injection parameter on velocity functions is presented in graphical form and discussed in detail. Verification of the solutions is made by a numerical comparison with the previous study.

关键词： Micropolar fluid Stagnation point Modified Darcy'slaw Porous medium

生长素和落叶对芥菜光合作用和乙烯演变的影响

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国外作物育种 2003年第4期22卷 25-25页

作者： n.a.khan 雷波

Interactive Effect of GA_3 ,n and P Ameliorate Growth, Seed and Fibre Yield by Enhancing Photosynthetic Capacity and Carbonic Anhydrase Activity of Linseed: A Dual Purpose Crop

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Journal of Integrative Agriculture 2013年第7期12卷 1183-1194页

作者： Mohammad n khan Firoz Mohammad Department of Biology Faculty of Science University of Tabuk Plant Physiology Section Department of Botany Aligarh Muslim University

Linseed （Linum usitatissimum L.） is an important dual-purpose, industrial crop. Its seeds are used for the extraction of oil and stem for fibres. However, the production of linseed is not going parallel with the increasing demand of its products. The present work was carried out with an aim to find out whether exogenous application of gibberellic acid （GA3） with or without graded levels of nitrogen （n） and phosphorus （P） could improve the performance of three linseed genotypes Parvati, Shekhar and Shubhra together with minimizing the costly fertilizer input and losses. Four combinations of n and P, viz., 0 mg n＋0 mg P kg-1 soil （n0P0）, n13.4 P4.46 , n26.8P8.94 and n40.2P13.4 were constituted. Half dose of each combination was applied basally at the time of sowing and remaining half dose was given at 40 d after sowing （DAS） as foliar spray along with 10-6 mol L-1 GA3 . Prior to sowing, the seeds of each linseed genotype were grouped in to two, one group of seeds was soaked in 0 mol L-1 GA3 （control） and the other group was soaked in 10-6 M GA3 solution, each for 8 hours. Treatments were comprised of （i） 0 mol L-1 GA3＋n0P0 （T0 , control）, （ii） 10-6 mol L-1 GA3 ＋ n13.4P4.46 （T1）, （iii） 10-6 mol L-1 GA 3 ＋n 26.8 P 8.94 （T2） and （iv） 10-6 mol L-1 GA3＋n40.2P13.4 （T3）. The crop performance was assessed in terms of growth, physiological and biochemical parameters at 60 and 75 DAS and yield attributes at harvest （175 DAS）. The results showed a parallel increase in most of the parameters with increasing levels of n and P. However, application of 10-6 mol L-1 GA3 in association with n26.8P8.94 proved best, it enhanced seed yield, oil yield and fibre yield by 83.3, 97.3 and 78.7%, respectively accompanied with increase in net photosynthetic rate, carbonic anhydrase activity and dry matter accumulation. Among the genotypes tested, Shubhra performed best, while Parvati the least for most of the parameters studied. Thus, combined application of 10-6 mol L-1 GA3 plus n26.8P8.94 pro

关键词： gibberellin photosynthesis crbonic anhydrase linseed

nucleoside modified mRnA-lipid nanoparticles as a new delivery platform for the repair of the injured spinal cord

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neural Regeneration Research 2025年第8期20卷 2311-2312页

作者： Krisztián Pajer Tamás Bellák Antal nógrádi Department of Anatomy Histology and EmbryologyAlbert Szent-Györgyi Medical SchoolUniversity of SzegedSzegedHungary

Spinal cord injury and treatment opportunities:The adult mammalian spinal cord has a very limited capacity for spontaneous regeneration due to various intrinsic molecular and cellular *** the spinal cord neurons have the capacity to regenerate their axons,the expression of growth inhibitory factors,lack or suppression of proper guidance cues,and profound inflammatory responses do not permit successful regeneration(Khyeam et al.,2021).

关键词： injured capacity modified

Impacts of PI3K/protein kinase B pathway activation in reactive astrocytes: from detrimental effects to protective functions

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neural Regeneration Research 2025年第4期20卷 1031-1041页

作者： Ramón Pérez-núñez María Fernanda González Ana María Avalos Lisette Leyton Cellular Communication Laboratory Programa de Biología Celular y MolecularCenter for Studies on ExerciseMetabolism and Cancer(CEMC)Instituto de Ciencias Biomédicas(ICBM)Facultad de MedicinaUniversidad de ChileSantiagoChile Advanced Center for Chronic Diseases(ACCDiS) Faculty of Chemical and Pharmaceutical Sciences&Faculty of MedicineUniversidad de ChileSantiagoChile Instituto de Ciencias Biomédicas Facultad de Ciencias de la SaludUniversidad Autónoma de ChileSantiagoChile

Astrocytes are the most abundant type of glial cell in the central nervous *** injury and inflammation,astrocytes become reactive and undergo morphological and functional *** on their phenotypic classification as A1 or A2,reactive astrocytes contribute to both neurotoxic and neuroprotective responses,***,this binary classification does not fully capture the diversity of astrocyte responses observed across different diseases and *** analysis has revealed that reactive astrocytes have a complex landscape of gene expression profiles,which emphasizes the heterogeneous nature of their *** actively participate in regulating central nervous system inflammation by interacting with microglia and other cell types,releasing cytokines,and influencing the immune *** phosphoinositide 3-kinase(PI3K)/protein kinase B(AKT)signaling pathway is a central player in astrocyte reactivity and impacts various aspects of astrocyte behavior,as evidenced by in silico,in vitro,and in vivo *** astrocytes,inflammatory cues trigger a cascade of molecular events,where nuclear factor-κB serves as a central mediator of the pro-inflammatory ***,we review the heterogeneity of reactive astrocytes and the molecular mechanisms underlying their *** highlight the involvement of various signaling pathways that regulate astrocyte reactivity,including the PI3K/AKT/mammalian target of rapamycin(mTOR),αvβ3 integrin/PI3K/AKT/connexin 43,and notch/PI3K/AKT *** targeting the inactivation of the PI3K/AKT cellular signaling pathway to control reactive astrocytes and prevent central nervous system damage,evidence suggests that activating this pathway could also yield beneficial *** dual function of the PI3K/AKT pathway underscores its complexity in astrocyte reactivity and brain function *** review emphasizes the importance of employing astrocyte-exclusive models to underst

关键词： inflammation integrins neuroprotective neurotoxic phosphatidylinositol 3-kinase reactive astrocytes signal transduction Thy-1(CD90)

Sex differences in aging and injured brain

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neural Regeneration Research 2025年第10期20卷 2901-2902页

作者： Jordan n.Williamson Yuan Yang University of Illinois Urbana-Champaign Grainger College of EngineeringDepartment of BioengineeringUrbanaILUSA Carle Foundation Hospital Stephenson Family Clinical Research InstituteClinical Imaging Research CenterUrbanaILUSA University of Illinois Urbana-Champaign Beckman Institute for Advanced Science and TechnologyUrbanaILUSA northwestern University Department of Physical Therapy and Human Movement SciencesChicagoILUSA

Background:The prevalence,age of onset,and symptomatology of traumatic brain injury,stroke,and neurodegenerative diseases(such as Alzheimer’s disease(AD),Parkinson’s disease,amyotrophic lateral sclerosis,and Huntington’s disease)differ substantially between males and *** higher prevalence of these brain disorders has been attributed to females having a greater longevity compared with *** one of the greatest risk factors of acquired brain injury(such as stroke,traumatic brain injury caused by fall)and neurodegenerative disease is age.

关键词： Huntington prevalence traumatic

Astrocytes, reactive astrogliosis, and glial scar formation in traumatic brain injury

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neural Regeneration Research 2025年第4期20卷 973-989页

作者： María Belén Cieri Alberto Javier Ramos Laboratorio de neuropatología Molecular IBCN UBA-CONICETFacultad de MedicinaUniversidad de Buenos AiresBuenos AiresArgentina

Traumatic brain injury is a global health crisis,causing significant death and disability *** that follows traumatic brain injury has serious consequences for neuronal survival and cognitive impairments,with astrocytes involved in this *** traumatic brain injury,astrocytes rapidly become reactive,and astrogliosis propagates from the injury core to distant brain *** astroglial proteins are downregulated near the traumatic brain injury core,while pro-inflammatory astroglial genes are *** altered gene expression is considered a pathological remodeling of astrocytes that produces serious consequences for neuronal survival and cognitive *** addition,glial scar formed by reactive astrocytes is initially necessary to limit immune cell infiltration,but in the long term impedes axonal reconnection and functional *** therapeutic strategies for traumatic brain injury are focused on preventing acute ***,cannabinoids,progesterone,beta-blockers,and cerebrolysin demonstrate neuroprotective benefits but most of them have not been studied in the context of *** this review,we discuss the cell signaling pathways activated in reactive astrocytes following traumatic brain injury and we discuss some of the potential new strategies aimed to modulate astroglial responses in traumatic brain injury,especially using cell-targeted strategies with miRnAs or lncRnA,viral vectors,and repurposed drugs.

关键词： astrocyte glial scar innate immunity neuroinflammation stab injury Toll-like receptors

Making bridges between preclinical and clinical insights into age-related cognitive decline

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neural Regeneration Research 2025年第8期20卷 2321-2322页

作者： David VC Brito Clévio nóbrega Algarve Biomedical Center-Research Institute(ABC-RI) Campus GambelasFaroPortugal Algarve Biomedical Center-(ABC) Campus GambelasFaroPortugal Faculty of Medicine and Biomedical Sciences(FMCB) University of AlgarveGambelas CampusFaroPortugal

With people living longer,the societal impact of age-related cognitive decline is becoming more pronounced(Crimmins,2015).Thus,it is increasingly important to comprehend the cognitive shifts linked to aging-whether th... 详细信息

关键词： bridges becoming insight