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Applied Mathematics and Mechanics(English Edition) 2024年第3期45卷 407-424页

作者： M.SAFI M.VAKILIFARD M.j.MAHMOODI Faculty of Civil Water&Environmental EngineeringShahid Beheshti UniversityTehran ***Iran Faculty of Mechanical and Energy Engineering Shahid Beheshti UniversityTehran ***Iran

In this paper,layered periodic foundations(LPFs)are numerically examined for their responses to longitudinal and transverse modes in the time and frequency domains.Three different unit-cells,i.e.,2-layer,4-layer,and 6-layer unit-cells,comprising concrete/rubber,concrete/rubber/steel/rubber,and concrete/rubber/steel/rubber/lead/rubber materials,respectively,are taken into account.Also,the viscoelasticity behavior of the rubber is modeled with two factors,i.e.,a frequency-independent(FI)loss factor and a linear frequency-dependent(FD)loss factor.Following the extraction of the complex dispersion curves and the identification of the band gaps(BGs),the simulations of wave transmission in the time and frequency domains are performed using the COMSOL software.Subsequent parametric studies evaluate the effects of the rubber viscoelasticity models on the dispersion curves and the wave transmission for the longitudinal and transverse modes.The results show that considering the rubber viscoelasticity enhances the wave attenuation performance.Moreover,the transverse-mode damping is more sensitive to the viscoelasticity model than its longitudinal counterpart.The 6-layer unit-cell LPF exhibits the lowest BG,ranging from 4.8 Hz to 6.5 Hz.

关键词： layered metamaterial periodic foundation complex dispersion curve wave transmission diagram

Use of donepezil for neurocognitive recovery after brain injury in adult and pediatric populations:a scoping review

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Neural Regeneration Research 2024年第8期19卷 1686-1695页

作者： Avery L.Miller Nathan K.Evanson j.Michael Taylor University of Cincinnati College of Medicine CincinnatiOHUSA Department of Pediatrics University of CincinnatiCincinnatiOHUSA Department of Neurology and Rehabilitation Medicine University of CincinnatiCincinnatiOHUSA Division of Pediatric Rehabilitation Medicine Cincinnati Children’s Hospital Medical CenterCincinnatiOHUSA Division of Neurology Cincinnati Children’s Hospital Medical CenterCincinnatiOHUSA

There are few pharmacologic options for the treatment of cognitive deficits associated with traumatic brain injury in pediatric patients.Acetylcholinesterase inhibitors such as donepezil have been evaluated in adult patients after traumatic brain injury,but relatively less is known about the effect in pediatric populations.The goal of this review is to identify knowledge gaps in the efficacy and safety of acetylcholinesterase inhibito rs as a potential a djuvant treatment fo r neurocognitive decline in pediatric patients with traumatic brain injury.Investigators queried PubMed to identify literature published from database inception thro ugh june 2023 desc ribing the use of donepezil in young adult traumatic brain injury and pediatric patients with predefined conditions.Based on preselected search criteria,340 unique papers we re selected for title and abstra ct screening.Thirty-two reco rds were reviewed in full after eliminating preclinical studies and pape rs outside the scope of the project.In adult traumatic brain injury,we review results from 14 papers detailing 227 subjects where evidence suggests donepezil is well tole rated and shows both objective and patient-reported efficacy for reducing cognitive impairment.In children,3 pape rs report on 5 children recovering from traumatic brain injury,showing limited efficacy.An additional 15 pediatric studies conducted in populations at risk for cognitive dysfunction provide a broader look at safety and efficacy in 210 patients in the pediatric age group.Given its promise for efficacy in adults with traumatic brain injury and tole rability in pediatric patients,we believe further study of donepezil for children and adolescents with traumatic brain injury is warranted.

关键词： acetylcholinesterase inhibitor adult cognition donepezil pediatrics traumatic brain injury

On the Trail of Self-Directed Online Learners

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ECNU Review of Education 2024年第2期7卷 406-419页

作者： Curtis j.Bonk 朱美娜 School of Education Indiana University201 N.Rose AvenueBloomingtonIN 4740lUSA Wayne State University

Purpose We describe a series of more than a dozen studies on self-directed online learning spanning over a decade.Design/Approach/Methods We incorporated surveys,interviews,focus groups,and content analyses into these research studies,which initially targeted the goals,motivations,and challenges of learners using open educational resources and OpenCourseWare and then focused on learning from massive open online courses(MOOCs).This research accelerated after creating a database of over 3,000 MOOC instructors,through which we explored cultural sensitivity and personalization practices in MOOCs as well as instructional design considerations and challenges,MOOC instructor professional development and career development,instructor motivation and engagement,and student and instructor perceptions of self-directed learning.Findings This study reveals that self-directed online learners(SDOLs)seek learning environments offering freedom,choice,control,and a sense of autonomy and that both learners and instructors have intrinsic motivation for engaging in open online learning environments.Originality/Value Based on this research with both MOOC instructors and MOOC learners,we offer instructional design guidelines to address SDOLs’needs and assist in efforts to foster a new generation of SDOLs.

关键词： MOOCs motivation online learning self-directed learning self-management self-monitoring

Biomaterials and emerging technologies for tissue engineering and in vitro models

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Bio-Design and Manufacturing 2024年第3期7卷 237-239页

作者： j.Miguel Oliveira Rui L.Reis 3B’s Research Group I3Bs-Research Institute on BiomaterialsBiodegradables and BiomimeticsHeadquarters of the European Institute of Excellence on Tissue Engineering and Regenerative MedicineUniversity of MinhoAveParkZona Industrial da Gandra4805-017 BarcoGuimarãesPortugal ICVS/3B’s-PT Government Associate Laboratory 4806-909 Braga/GuimarãesPortugal

The latest advances in the field of biomaterials have opened new avenues for scientific breakthroughs in tissue engineer-ing which greatly contributed for the successful translation of tissue engineering products into the market/clinics.Bio-materials are easily processed to become similar to natural extracellular matrix,making them ideal temporary supports for mimicking the three-dimensional(3D)microenvironment required for maintaining the adequate cell/tissue functions both in vitro and in vivo^([1]).

关键词： breakthrough biomaterials engineer

Analysis of synthetic parameters for coating aluminum powders with phenyltriethoxysilane coupling agent and their effects on powder flow behavior

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Particuology 2024年第7期90卷 412-417页

作者： Lillian M.Mawby Bellamarie Ludwig Benjamin j.Lear Department of Chemistry The Pennsylvania State UniversityUniversity ParkPA16802USA Applied Research Laboratory The Pennsylvania State UniversityUniversity ParkPA16802USA

Though silanization of aluminum powder is currently used to improve its flow properties,for use as an alternative fuel source,there are a wide range of experimental parameters for the process and not all of them have been thoroughly explored.Until this is complete,it is unknown if the process is optimized in terms of time,efficiency,and effect.Herein,we report on a study into the effects of changes in humidity,degree of agitation,reaction temperature,and curing time upon the deposition of phenyl triethoxysilane into 20μm(d50)aluminum particles.We confirm the deposition of the coating via diffuse reflectance infrared spectroscopy and x-ray photoelectron spectroscopy.We then characterize the coated particles using apparent density measurements and Carney flow methods.Using analysis of variance,we find that,of the parameters explored,only changes in cure time and reaction temperature provide meaningful changes to the apparent density,while none of our parameters produced statistically significant changes in Carney flow values.Thus,we conclude that,when optimizing silanization of aluminum particles,environmental control of humidity is unneeded and that the reaction can be run with minimal agitation.The ability to largely ignore these parameters is a benefit to large-scale processing.

关键词： Aluminum powder Silane Fluidization Apparent density Carney flow

Translating Pathological Brain Activity Primers in Parkinson’s Disease Research

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Research 2024年第1期2023卷 735-752页

作者： Daniela Mirzac Svenja L.Kreis Heiko j.Luhmann Gabriel Gonzalez-Escamilla Sergiu Groppa Movement Disorders and Neurostimulation Department of NeurologyFocus Program Translational NeuroscienceRhine Main Neuroscience NetworkUniversity Medical Center of the Johannes Gutenberg University Mainz55131 MainzGermany Institute of Physiology University Medical Center of the Johannes Gutenberg University Mainz55131 MainzGermany

Translational experimental approaches that help us better trace Parkinson’s disease(PD)pathophysiological mechanisms leading to new therapeutic targets are urgently needed.In this article,we review recent experimental and clinical studies addressing abnormal neuronal activity and pathological network oscillations,as well as their underlying mechanisms and modulation.Our aim is to enhance our knowledge about the progression of Parkinson's disease pathology and the timing of its symptom’s manifestation.Here,we present mechanistic insights relevant for the generation of aberrant oscillatory activity within the cortico-basal ganglia circuits.We summarize recent achievements extrapolated from available PD animal models,discuss their advantages and limitations,debate on their differential applicability,and suggest approaches for transferring knowledge on disease pathology into future research and clinical applications.

关键词： clinical knowledge insight

A quantitative analysis of the US materials flow methodology and comparison to the EU methodology for MSW statistics

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Waste Disposal and Sustainable Energy 2024年第1期6卷 85-94页

作者： Demetra Tsiamis Fabio Poretti Stefano Consonni Marco j.Castaldi Earth Engineering Center Department of Chemical EngineeringThe City College of New YorkNew YorkNYUSA Dipartimento Di Energetica Politecnico Di MilanoPiazza Leonardo da Vinci 3220133MilanItaly

The European Union(EU)and the United States(US)determine municipal solid waste(MSW)statistics differently.The EU applies a site-specific methodology that directly measures waste whereas the US employs a materials flow methodology that estimates MSW statistics indirectly based on production and recovery data from industries.This study dissects the materials flow methodology and presents quantitative materials flow Sankey diagrams for the primary MSW materials to highlight data gaps that can be addressed to improve the methodology’s accuracy.Private industry plastics data were applied to the materials flow methodology,and the results were within 10%of the plastics statistics reported by the US Environmental Protection Agency(US EPA).Drawbacks to the methodologies include EU measurement inaccuracies due to double-counting and not accounting for residual waste in the US.The latter may partially explain why landfilling tonnages reported by the US EPA were approximately 60%less than the tonnages reported by the Waste to Energy Research and Technology Council(WTERT)in its national MSW survey that applied the EU methodology in the US.Unlike the EU,there is no US national policy that requires states to measure and report state-level waste data to the US EPA.Future improvements in US MSW statistics rely heavily on the implementation of national policies to homogenize the measurement and collection of waste data from states.

关键词： Materials flow methodology Site-specific methodology United States European Union Municipal solid waste Discrepancy

Adenosine A_(2A)receptor blockade attenuates excitotoxicity in rat striatal medium spiny neurons during an ischemic-like insult

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Neural Regeneration Research 2024年第2期19卷 255-257页

作者： Elisabetta Coppi Federica Cherchi Alasdair j.Gibb Department of Neuroscience PsychologyDrug Research and Child HealthUniversity of FlorenceFlorenceItaly Department of Neuroscience Physiology and PharmacologyUniversity College LondonLondonUK

During brain ischemia,excitotoxicity and peri-infarct depolarization injuries occur and cause cerebral tissue damage.Indeed,anoxic depolarization,consisting of massive neuronal depolarization due to the loss of membrane ion gradients,occurs in vivo or in vitro during an energy failure.The neuromodulator adenosine is released in huge amounts during cerebral ischemia and exerts its effects by activating specific metabotropic receptors,namely:A_(1),A_(2A),A_(2B),and A_(3).The A_(2A)receptor subtype is highly expressed in striatal medium spiny neurons,which are particularly susceptible to ischemic damage.Evidence indicates that the A2Areceptors are upregulated in the rat striatum after stroke and the selective antagonist SCH58261 protects from exaggerated glutamate release within the first 4 hours from the insult and alleviates neurological impairment and histological injury in the following 24 hours.We recently added new knowledge to the mechanisms by which the adenosine A2Areceptor subtype participates in ischemia-induced neuronal death by performing patch-clamp recordings from medium spiny neurons in rat striatal brain slices exposed to oxygen and glucose deprivation.We demonstrated that the selective block of A2Areceptors by SCH58261 significantly reduced ionic imbalance and delayed the anoxic depolarization in medium spiny neurons during oxygen and glucose deprivation and that the mechanism involves voltage-gated K+channel modulation and a presynaptic inhibition of glutamate release by the A2Areceptor antagonist.The present review summarizes the latest findings in the literature about the possibility of developing selective ligands of A2Areceptors as advantageous therapeutic tools that may contribute to counteracting neurodegeneration after brain ischemia.

关键词： adenosine A_(2A)receptors anoxic depolarization brain ischemia glutamate excitotoxicity medium spiny neurons oxygen and glucose deprivation

Laboratory Implementation of Direct Torque Controller based Speed Loop Pseudo Derivative Feedforward Controller for PMSM Drive

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CES Transactions on Electrical Machines and Systems 2024年第1期8卷 12-21页

作者： Prabhakaran Koothu Kesavan Umashankar Subramaniam Dhafer j.Almakhles IEEE Renewable Energy Laboratory Department of Electrical EngineeringPrince Sultan UniversityRiyadh 12435Saudi Arabia

This paper,evaluate the effectiveness of a proposed speed loop pseudo derivative feedforward(PDFF)controller-based direct torque controller(DTC)for a PMSM drive against the performance of existing PI speed controller-based DTC and hysteresis current controller(HCC).The proposed PDFF-based speed regulator effectively reduces oscillation and overshoot associated with rotor angular speed,electromagnetic torque,and stator current.Two case studies,one using forward-to-reverse motoring operation and the other involving reverse-to-forward braking operation,has been validated to show the effectiveness of the proposed control strategy.The proposed controller's superior performance is demonstrated through experimental verification utilizing an FPGA controller for a 1.5 kW PMSM drive laboratory prototype.

关键词： Direct torque control Pseudo derivative feedforward controller Permanent magnet synchronous motor(PMSM)

A Tutorial Review of the Solar Power Curve: Regressions, Model Chains, and Their Hybridization and Probabilistic Extensions

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Advances in Atmospheric Sciences 2024年第6期41卷 1023-1067页

作者： Dazhi YANG Xiang’ao XIA Martin jános MAYER School of Electrical Engineering and Automation Harbin Institute of TechnologyHarbin 150001HeilongjiangChina Key Laboratory for Middle Atmosphere and Global Environment Observation(LAGEO) Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Department of Energy Engineering Faculty of Mechanical EngineeringBudapest University of Technology and EconomicsMűegyetem rkp.3Budapest H-1111Hungary

Owing to the persisting hype in pushing toward global carbon neutrality,the study scope of atmospheric science is rapidly expanding.Among numerous trending topics,energy meteorology has been attracting the most attention hitherto.One essential skill of solar energy meteorologists is solar power curve modeling,which seeks to map irradiance and auxiliary weather variables to solar power,by statistical and/or physical means.In this regard,this tutorial review aims to deliver a complete overview of those fundamental scientific and engineering principles pertaining to the solar power curve.Solar power curves can be modeled in two primary ways,one of regression and the other of model chain.Both classes of modeling approaches,alongside their hybridization and probabilistic extensions,which allow accuracy improvement and uncertainty quantification,are scrutinized and contrasted thoroughly in this review.

关键词： review energy meteorology solar power curve model chain solar power prediction