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A comprehensive investigation on nonlinear vibration and bending characteristics of bio-inspired helicoidal laminated composite structures

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Applied Mathematics and Mechanics(English Edition) 2025年第1期46卷 81-100页

作者： s.sAUrABH r.KIrAN D.sINGH r.VAIsH V.s.CHAUHAN school of Mechanical and Materials Engineering Indian Institute of Technology Mandi

Bio-inspired helicoidal composite laminates, inspired by the intricate helical structures found in nature, present a promising frontier for enhancing the mechanical properties of structural designs. Hence, this study provides a comprehensive investigation into the nonlinear free vibration and nonlinear bending behavior of bio-inspired composite plates. The inverse hyperbolic shear deformation theory(IHsDT) of plates is employed to characterize the displacement field, with the incorporation of Green-Lagrange nonlinearity. The problem is modeled using the C0finite element method(FEM), and an in-house code is developed in the MATLAB environment to solve it numerically. Various helicoidal layup configurations including helicoidal recursive(Hr), helicoidal exponential(HE), helicoidal semi-circular(Hs), linear helicoidal(LH), and Fibonacci helicoidal(FH)with different layup sequences and quasi-isotropic configurations are studied. The model is validated, and parametric studies are conducted. These studies investigate the effects of layup configurations, side-to-thickness ratio, modulus ratios, boundary conditions, and loading conditions at different load amplitudes on the nonlinear vibration and nonlinear bending behaviors of bio-inspired composite plates. The results show that the laminate sequence exerts a substantial impact on both nonlinear natural frequencies and nonlinear bending behaviors. Moreover, this influence varies across different side-to-thickness ratios and boundary conditions of the bio-inspired composite plate.

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Multiphysics of multifunctional nanofluids based on different oxides nanoparticles and glycerol fluid

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Particuology 2023年第5期76卷 46-62页

作者： r.J.sengwa Mukul saraswat Dielectric research Laboratory Department of PhysicsJai Narain Vyas UniversityJodhpur342005India

Nanofluid(NF)materials consisting of glycerol(Gly)and different inorganic nano oxides(TiO_(2),ZnO,Al_(2)O_(3),and siO_(2) for the oxides concentration of 0.01 wt%to the weight of Gly base fluid)were prepared by a two-step method through ultrasonic cavitation *** nanofluids were investigated by employing an X-ray diffractometer(XrD),ultraviolet-visible(UV-Vis)spectrophotometer,20 Hz to 1 MHz frequency range dielectric relaxation spectroscopy(Drs),ultrasonic interferometer,and rotational *** multiphysics of these nanofluids includes structural and optical properties,dielectric permittivity,electrical conductivity,conductivity relaxation,ultrasound velocity,adiabatic compress-ibility,acoustic impedance,viscosity,density,thermal conductivity,and viscoacoustic relaxation were *** XrD patterns identified monodispersed and stable suspensions of these different characteristic nanoparticles in the hydrogen-bonded 3D supramolecular structure of ultra-high viscous glycerol fluid which were supported by their UV-Vis absorbance *** energy band gap values of the TiO_(2)and ZnO containing nanofluids were found primarily ruled by the characteristic optical prop-erties of these oxides *** complex dielectric and various electrical functions studied at 25℃revealed that the suspension of different oxide nanoparticles in the glycerol fluid increased the static permittivity whereas reduced the direct current electrical conductivity which showed strong conductivity relaxation process *** rheological measurements of the formulated nanofluids were performed over a shear rate range of 0.4-40 s^(-1)at temperatures of 25-55℃.The linear rela-tionship between shear rate and shear stress and also the shear rate-independent viscosity revealed the Newtonian behaviour of these *** shear viscosity non-linearly decreased with the increase of temperature and exhibited the Arrhenius behaviour for all different oxides contain

关键词： Glycerol Nano oxides Nanofluids Optical properties Dielectric properties Thermophysical parameters

revisiting cerebral endothelial cells in Alzheimer’s disease

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Neural regeneration research 2025年第10期20卷 2911-2912页

作者： Amira s.Hanafy Department of Neurosurgery University Hospital BonnBonnGermany

Alzheimer’s disease(AD)is the most common neurodegenerative disorder characterized by slow and progressive decline of cognitive and memory *** only approximately 5%of the cases,AD is familial,as often predisposed by genetic mutations(Hoogmartens et al.,2021),while sporadic AD accounts for approximately 95%of the *** amyloid cascade hypothesis is one of the fundamental hypotheses put out to explain AD pathogenesis as dysregulated homeostasis of amyloid-β(Aβ)peptides that leads to the accumulation of Aβplaques in the parenchyma,an anatomical hallmark of AD.

关键词： Alzheimer Aβ cerebral

Emerging structures and dynamic mechanisms ofγ-secretase for Alzheimer’s disease

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Neural regeneration research 2025年第1期20卷 174-180页

作者： Yinglong Miao Michael s.Wolfe Computational Medicine Program and Department of Pharmacology University of North Carolina–Chapel HillChapel HillNCUSA Department of Medicinal Chemistry University of KansasLawrenceKSUSA

γ-secretase,called“the proteasome of the membrane,”is a membrane-embedded protease complex that cleaves 150+peptide substrates with central roles in biology and medicine,including amyloid precursor protein and the Notch family of cell-surface *** inγ-secretase and amyloid precursor protein lead to early-onset familial Alzheimer’s disease.γ-secretase has thus served as a critical drug target for treating familial Alzheimer’s disease and the more common late-onset Alzheimer’s disease as ***,critical gaps remain in understanding the mechanisms of processive proteolysis of substrates,the effects of familial Alzheimer’s disease mutations,and allosteric modulation of substrate cleavage byγ-*** this review,we focus on recent studies of structural dynamic mechanisms ofγ-*** mechanisms,including the“Fit-stay-Trim,”“sliding-Unwinding,”and“Tilting-Unwinding,”have been proposed for substrate proteolysis of amyloid precursor protein byγ-secretase based on all-atom molecular dynamics *** an incorrect registry of the Notch1 substrate was identified in the cryo-electron microscopy structure of Notch1-boundγ-secretase,molecular dynamics simulations on a resolved model of Notch1-boundγ-secretase that was reconstructed using the amyloid precursor protein-boundγ-secretase as a template successfully capturedγ-secretase activation for proper cleavages of both wildtype and mutant Notch,being consistent with biochemical experimental *** approach could be potentially applied to decipher the processing mechanisms of various substrates byγ-*** addition,controversy over the effects of familial Alzheimer’s disease mutations,particularly the issue of whether they stabilize or destabilizeγ-secretase-substrate complexes,is ***,an outlook is provided for future studies ofγ-secretase,including pathways of substrate binding and product release,effects of modulators on familial Alzheimer’s disease mutations

关键词： Alzheimer’s disease amyloid precursor protein cryo-EM structures drug design intramembrane proteolysis molecular dynamics Notch

Complementary roles of glial cells in generating region-specific neuroinflammatory responses and phagocytosis in Parkinson’s disease

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Neural regeneration research 2025年第10期20卷 2917-2918页

作者： Leyre Ayerra Maria s.Aymerich Universidad de Navarra Facultad de CienciasDepartamento de Bioquímica y GenéticaPamplonaSpain CIMA-Universidad de Navarra PamplonaSpain IdisNA Instituto de Investigación Sanitaria de NavarraPamplonaSpain

Neuroinflammation is associated with Parkinson’s disease:reactive gliosis and neuroinflammation are hallmarks of Parkinson’s disease(PD),a multisystem neurodegenerative disorder characterized by a progressive loss of dopaminergic *** has long been considered a mere consequence of neuronal loss,but whether it promotes PD or is a key player in disease progression remains to be *** leukocyte antigen.

关键词： inflammation leukocyte generating

Free vibration and transient response of double curved beams connected by intermediate straight beams

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Applied Mathematics and Mechanics(English Edition) 2025年第1期46卷 37-62页

作者： r.A.JAFArI-TALOOKOLAEI H.GHANDVAr E.JUMAEV s.KHATIr T.CUONG-LE school of Mechanical Engineering Babol Noshirvani University of Technology Department of Mechanical Engineering Faculty of Engineering New Uzbekistan University University of Business and science Center for Engineering Application and Technology solutions Ho Chi Minh City Open University

This paper investigates the free vibration and transient response of interconnected structures including double curved beams and intermediate straight beams,which are all constructed from functionally graded porous(FGP) materials. The strain potential and kinetic energies of each beam along with the work done by the external force are calculated. Additionally, a higher-order beam element is introduced to derive stiffness and mass matrices, along with the force vector. The curved and straight beams are discretized, and their assembled stiffness, mass matrices, and force vectors, are *** conditions at the joints are used to derive the total matrices of the entire structure. subsequently, the natural frequencies and transient response of the system are determined. The accuracy of the mathematical model and the self-developed computer program is validated through the comparison of the obtained results with those of the existing literature and commercial software ANsYs, demonstrating excellent ***, a comprehensive study is conducted to investigate the effects of various parameters on the free vibration and transient response of the considered structure.

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Getting physical with medical education:Exercise based virtual anatomy review classes for medical students

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World Journal of Methodology 2025年第1期15卷 20-25页

作者： Nadeesha r samarasinghe Taniya s Nagpal Michele L Barbeau Charys M Martin Division of General surgery Faculty of MedicineUniversity of British ColumbiaVancouver V6T 1Z3BCCanada Faculty of Kinesiology Sport and RecreationUniversity of AlbertaEdmonton T6G 2R3ABCanada Anatomy and Cell Biology University of Western OntarioLondon N6A 3K7ONCanada Department of Anatomy and Cell Biology Schulich School of Medicine and DentistryThe University of Western OntarioLondon N6A 3K7ONCanada

The benefits of regular physical activity are well ***,few studies have examined the effectiveness of integrating physical activity(PA)into curricula within a post-secondary *** investigate the incorporation of PA into medical curriculum,we developed a series of optional exercise-based review sessions designed to reinforce musculoskeletal(MsK)anatomy course *** synchronous sessions were co-taught by a group fitness instructor and an anatomy *** fitness instructor would lead students through both strength and yoga style exercises,while the anatomy instructor asked questions about relevant anatomical structures related to course material previously *** the sessions,participants were asked to evaluate the classes on their self-reported exam preparedness in improving MsK anatomy knowledge,PA levels,and mental *** participants completed surveys;a majority agreed that the classes increased understanding of MsK concepts(90.0%)and activity levels(97.7%).Many(70.0%)felt that the classes helped reduce *** majority of respondents(90.0%)agreed that the classes contributed to increased feelings of social ***,medical students saw benefit in PA based interventions to supplement MsK course *** with increasing activity levels and promoting health behaviours,integrating PA into medical curriculum may improve comprehension of learning material,alleviate stress and foster social connectivity among medical students.

关键词： Medical education Musculoskeletal Anatomy Exercise Online learning

simulation of Case Depth of Cementation steels According to Fick’s Laws

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Journal of Iron and steel research International 2012年第11期19卷 71-78页

作者： s r Elmi Hosseini Faculty of Engineering Department of Materials Science and EngineeringUniversity of Sistan and Baluchestan

The carburizing process is the enrichment of the depth of low carbon steels with carbon. It leads to samples with a combination of high surface hardness and high core toughness and to an impact strength that is required for many engineering parts. The material studied is a low carbon steel. The carbon content is little in this type of steel （wc = 0.2 ~）. The calculation of case depth is very important for cementation steels that are hardened in the carburi- zing process. The effective case depth is defined as the perpendicular distance from the surface to a place at which the hardness is HV 550. Nowadays, a great number of studies have been carried out on the simulation of effective case depth, but no studies have been conducted to determine the numerical relation between the total case depth on one hand and the carburizing time and the effective case depth on the other hand. The steel specimens were subjected to graphite powder. Then, they were heat treated at 925 ~C for about 3, 5, 8 and 12 h, respectively. Then, these parts were quenched in oil. To determine the effective case depth, the micr0hardness test was performed on the cross-section of specimens. Plotting the case depth vs carburizing time, the required conditions for obtaining the specified case depth were determined. Also, the comparison between the case depths in numerical solution and the actual position in pack carburizing was performed.

关键词： cementation steel carburizing case depth Fick's law simulation

Charged current quasi-elastic scattering of vμoff^12C

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Chinese Physics C 2018年第12期42卷 25-31页

作者： Deepika Grover Kapil saraswat Prashant shukla Venktesh singh Department of Physics Institute of ScienceBanaras Hindu UniversityVaranasi 221005India Nuclear Physics Division Bhabha Atomic Research CentreMumbai 400085India Homi Bhabha National Institute Anushakti NagarMumbai 400094India

In this work, we study charged current quasi-elastic scattering （QEs） of vμ off nucleon and nucleus using a formalism based on the Llewellyn smith （Ls） model. Parameterizations by Galster et al. are used for electric and magnetic sach＇s form factors of the nucleons. We use the Fermi gas model along with the Pauli suppression condition to take into account the nuclear effects in the anti-neutrino-nucleus QEs. We calculate vμ-p and vμ-^12C charged current quasi-elastic scattering differential and total cross sections for different values of axial mass MA, and compare the results with data from the GGM, sKAT, BNL, NOMAD, MINErVA and MiniBooNE experiments. The present theoretical approach gives a good description of differential cross section data. The calculations with axial mass MA =0.979 and 1.05 GeV are compatible with data from most of the experiments.

关键词： cross section quasi-elastic scattering axial mass form factors