检索结果-南通市图书馆

Modulation of the Nogo signaling pathway to overcome amyloid-β-mediated neurite inhibition in human pluripotent stem cell-derived neurites

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Neural Regeneration Research 2025年第9期20卷 2645-2654页

作者： Kirsty Goncalves stefan Przyborski Department of Biosciences Durham UniversityDurhamUK Reprocell Europe Ltd. GlasgowUK

Neuronal cell death and the loss of connectivity are two of the primary pathological mechanisms underlying Alzheimer's *** accumulation of amyloid-βpeptides,a key hallmark of Alzheimer's disease,is believed to induce neuritic abnormalities,including reduced growth,extension,and abnormal growth cone morphology,all of which contribute to decreased ***,the precise cellular and molecular mechanisms governing this response remain *** this study,we used an innovative approach to demonstrate the effect of amyloid-βon neurite dynamics in both two-dimensional and three-dimensional cultu re systems,in order to provide more physiologically relevant culture *** utilized various methodologies,including the addition of exogenous amyloid-βpeptides to the culture medium,growth substrate coating,and the utilization of human-induced pluripotent stem cell technology,to investigate the effect of endogenous amyloid-βsecretion on neurite outgrowth,thus paving the way for potential future applications in personalized ***,we also explore the involvement of the Nogo signaling cascade in amyloid-β-induced neurite *** demonstrate that inhibition of downstream ROCK and RhoA components of the Nogo signaling pathway,achieved through modulation with Y-27632(a ROCK inhibitor)and Ibuprofen(a Rho A inhibitor),respectively,can restore and even enhance neuronal connectivity in the presence of amyloid-β.In summary,this study not only presents a novel culture approach that offers insights into the biological process of neurite growth and inhibition,but also proposes a specific mechanism for reduced neural connectivity in the presence of amyloid-βpeptides,along with potential intervention points to restore neurite ***,we aim to establish a culture system that has the potential to serve as an assay for measuring preclinical,predictive outcomes of drugs and their ability to promote neurite outgrowth,both generally and in a patie

关键词： Alzheimer's disease induced pluripotent stem cell neurite outgrowth neuron Nogo Rho A ROCK stem cell three-dimensional culture

Light tuning CO/H_(2)composition on Ag:Unraveling CO_(2)mass transfer and electron-phonon coupling in plasmon-enhanced electrocatalysis

在线全文

学校读者我要写书评

暂无评论

Nano Research 2025年第1期18卷 173-185页

作者： Rui Lin Dong Fan Luca MBerger Thomas Possmayer Yu Zhou Jiexin Zhu Xingbao Chen Wen Luo Lars Allmendinger Andreas Tittl Leonardo de Souza Menezes Guillaume Maurin Shihe Yang and stefan AMaier Nanoinstitute Munich Faculty of PhysicsLudwig-Maximilians-Universität München80539 MunichGermany Institut Charles Gerhardt Montpellier UMR 5253 CNRS ENSCM UniversitéMontpellierPlace E.Bataillon34090 MontpellierFrance Guangdong Provincial Key Lab of Nano-Micro Material Research School of Advanced MaterialsPeking University Shenzhen Graduate SchoolShenzhen 518055China State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of TechnologyWuhan 430070China Faculty of Chemistry and Pharmacy Ludwig-Maximilians-Universität München81377 MunichGermany Departamento de Física Universidade Federal de Pernambuco50670-901 Recife-PEBrazil School of Physics and Astronomy Monash University Clayton CampusMelbourneVictoria 3800Australia Department of Physics Imperial College LondonSW72AZ LondonUK

Plasmon-enhanced electrocatalysis(PEEC)is an emerging approach to mitigate CO_(2)*** mechanisms behind CO_(2)adsorption and reduction at the catalyst-electrolyte interface in PEEC still need to be further ***,we employ a well-defined Ag nanostructure to elucidate these pivotal *** shining light with wavelengths of 625,525,405 nm on Ag,an adjustable CO/H_(2)ratio from 35 to 1 can be *** reaction pathway changing under plasmonic excitation does not originate from the lowered CO_(2)mass transfer in the vicinity of Ag,as the electrochemical quartz crystal microbalance results unravel that a slightly elevated temperature in bulk electrolyte caused by light irradiation cannot weaken the CO_(2)adsorption at the Ag catalyst-electrolyte *** calculations reveal that optical excitation towards shorter wavelengths leads to a progressive lowered energy barrier for H_(2)formation together with an enhanced energy barrier for^(*)COOH *** thermodynamically suppressed,CO_(2)reduction can still be improved kinetically by optimizing the excitation wavelength and intensity,being accompanied with the enhanced *** absorption spectroscopy results further correlate the higher photocurrent with a prolonged electron-phonon coupling time,verifying that the improvement of CO_(2)reduction kinetics in PEEC can be realized by hot electron harnessing.

关键词： plasmonic catalysis photoelectrochemical CO_(2)reduction CO/H_(2)ratio hot electron generation electronphonon coupling thermal effect

Generalized Sampling in Shift Invariant Spaces with Frames

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2012年第9期28卷 1823-1844页

作者： stefan ERICSSON Department of Engineering Sciences and Mathematics Lule University of Technology

Generalized sampling in a shift invariant subspace V of L2（R） is considered. A function f in V is processed with different filters Lm and then one tries to reconstruct f from the samples L^mf（j＇k）. We develop a theory of how to do this in the case when V possesses a shift invariant frame. Special attention is paid to the question： How to obtain dual frames with compact support？

关键词： Generalized sampling frames Riesz basis reproducing kernel shift invariant spaces

Constitutive relations for the shear band evolution in granular matter under large strain

在线全文

学校读者我要写书评

暂无评论

Particuology 2008年第6期6卷 501-505页

作者： stefan Luding Multi Scale Mechanics TS CTW UTwente P.O. Box 217 7500 AE Enschede Netherlands

A so-called ＂split-bottom ring shear cell＂ leads to wide shear bands under slow, quasi-static deformation. Unlike normal cylindrical Couette shear cells or rheometers, the bottom plate is split such that the outer part of it can move with the outer wall, while the other part （inner disk） is immobile. From discrete element simulations （DEM）, several continuum fields like the density, velocity, deformation gradient and stress are computed and evaluated with the goal to formulate objective constitutive relations for the powder flow behavior. From a single simulation, by applying time- and （local） space-averaging, a non-linear yield surface is obtained with peculiar stress dependence. The anisotropy is always smaller than the macroscopic friction coefficient. However, the lower bound of anisotropy increases with the strain rate, approaching the maximum according to a stretched exponential with a specific rate that is consistent with a shear path of about one particle diameter.

关键词： Ring shear cell Shear bands DEM simulation Micro-macro transition Objective constitutive relations Yield stress fluid

Experimental investigation on slip conditions during thread rolling with flat dies

在线全文

学校读者我要写书评

暂无评论

Friction 2024年第1期12卷 136-143页

作者： stefan VOLZ Peter GROCHE Institute for Production Engineering and Forming Machines Technical University DarmstadtOtto-Berndt Straße 2Darmstadt 64287Germany

The process design of flat die rolling operations can be a tedious and costly process due to the challenges posed by small process *** this work,an effort is made to closely investigate and understand the process limits caused by excessive slippage of the *** measurements are carried out to capture the characteristics of excessive slippage and the influence of the stroke rate and the tribological system on this process *** differences in slippage were observed,depending on the tribological *** systems with polymer based lubricants showed excessive slippage at low stroke rates,systems using oil or no lubricant endured higher stroke rates before process limits were *** optical measurements revealed three major forms of slippage:successful rolling without slippage,failure due to excessive slippage at process start,and failure due to excessive slippage at around one workpiece rotation.

关键词： rolling incremental forming thread rolling slippage profile rolling

Influence of sample preparation on nanoindentation results of twinninginduced plasticity steel

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2021年第5期28卷 877-887页

作者： Jiali Zhang stefan Zaefferer Institute for Materials Applications in Mechanical Engineering RWTH Aachen UniversityAachen 52062Germany Max-Planck-Institut für Eisenforschung Düsseldorf 40237Germany

Nanoindentation is an attractive characterization technique,as it not only measures the local properties of a material but also facilitates understanding of deformation mechanisms at submicron ***,because of the complex stress-strain field and the small scale of the deformation under the nanoindenter,the results can be easily influenced by artifacts induced during sample *** this work,a systematic study was conducted to better understand the influence of sample preparation methods on the nanoindentation results of ductile *** experiments were conducted on a steel(Fe-22Mn-0.65C,wt%)with twinning-induced plasticity(TWIP),which was selected for its large grain size and sensitivity to different surface preparation *** grouping the results obtained from each nanoindent,chemical polishing was found to be the best sample preparation method with respect to the resulting mechanical properties of the *** contrast,the presence of a deformation layer left by mechanical polishing and surface damage induced by focused ion beam(FIB)scanning were confirmed by the dislocation-nucleation-induced pop-in events of nanoindentation.

关键词： TWIP steels nanoindentation mechanical polishing chemical polishing pop-in

Hopf algebras and Dyson-Schwinger equations

在线全文

学校读者我要写书评

暂无评论

Frontiers of physics 2016年第3期11卷 161-177页

作者： stefan Weinzierl PRISMA Cluster of Excellence Institut fiir Physik Johannes Gutenberg- Universitiit Mainz D - 55099 Mainz Germany

In this paper I discuss Hopf algebras and Dyson-Schwinger equations. This paper starts with an introduction to Hopf algebras, followed by a review of the contribution and application of Hopf algebras to particle physi... 详细信息

关键词： Feynman integrals Hopf algebras Dyson-Schwinger equations

Simulation of spray coating in a spouted bed using recurrence CFD

在线全文

学校读者我要写书评

暂无评论

Particuology 2019年第1期17卷 92-103页

作者： Paul Kieckhefena Thomas Lichtenegger Swantje Pietsch stefan Pirker stefan Heinrich Institute of Solids Process Engineering and Particle Technology Hamburg University of Technology. HamburgGermany Department for Particulate Flow Modelling. Johannes Kepler University LinzAustria Linz Institute of Technology (LIT) Johannes Kepler UniversityLinzAustria

Although numerical models such as the computational fluid dynamics–discrete element method (CFD–DEM) have enabled the accurate simulation of laboratory-scale apparatuses, the application of these methods to large-scale apparatuses with many particles and time scales ranging from minutes to hours remains a challenge. The recently developed recurrence CFD (rCFD) method seeks to overcome these issues in pseudo-periodic processes by extrapolating globally recurring patterns in a physically meaningful way and describing the transport and interaction of passive scalars using Lagrangian tracers. Spouted beds represent an interesting target because of the associated variety of flow regimes. They can be effectively described by CFD–DEM on the time scale of tens of seconds, whereas industrially relevant processes typically take hours. In this contribution, we established the validity of applying the Lagrangian rCFD method to spouted beds by demonstrating the accurate reproduction of the particle residence time distribution in a fictitious spray zone. The deposition of spray droplets onto tracer particles was simulated for 1 h, and the particle surface coverage distribution was estimated using a statistical approach for both an unstabilized prismatic spouted bed and one stabilized by draft plates.

关键词： CFD–DEM Recurrence CFD Spray coating Time-scale decoupling Spouted bed Draft plate

Product design based on discrete particle modeling of a fluidized bed granulator

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Particuology 2014年第1期12卷 13-24页

作者： Lennart Fries Sergiy Antonyuk stefan Heinrich Gerhard Niederreiter stefan Palzer Nestlé Research Center Institute of Solids Process Engineering and Particle Technology Hamburg University of Technology

Fluidized bed agglomeration is a process commonly used to construct powdered food or pharmaceuti cal products to improve their instant properties. This works analyzes the influence of a wide range of operating parameters （i.e., fluidization air flow rate, temperature, and liquid injection rate） on growth rate, process stability, and product particle structure. Different granulator configurations （i.e., top spray, Wurster coater, spouted bed） are compared using identical process parameters. The impacts of both pro cess variables and granulator geometry on the fluidization regime, the particle and collision dynamics, and the resulting product structure and corresponding properties are studied in detailed simulations using a discrete particle model （DPM） and labscale agglomeration experiments with amorphous dextrose syrup （DE21）. The combination of numerical and experimental results allows to correlate the kinetics of micro scale particle interactions and the final product properties （i.e., agglomerate structure and strength）. In conclusion, detailed DPM simulations are proven as a valuable tool for knowledgebased product design.

关键词： FluidizationAgglomerationDiscrete element methodFood powderCollision dynamics