The main purpose of this paper is to investigate the singularities of solutions to the single Tricomi equation with derivative term and combined memory term.In addition,the blow-up of the solution to the weakly couple...The main purpose of this paper is to investigate the singularities of solutions to the single Tricomi equation with derivative term and combined memory term.In addition,the blow-up of the solution to the weakly coupled system with memory term is also considered,where one is a power nonlinear term and the other is a derivative nonlinear term.Upper bound lifespan estimates of solution are obtained in the sub-critical by utilizing the test function method and iteration technique.The innovation of this paper focuses on the lifespan estimates of the solutions,which extends the well-known Strauss and Glassey conjectures.展开更多
The distinctive feature of the adaptive immune system is its ability to generate immunological memory that can provide defense against subsequent infections.In the case of antibody-mediated immune responses,this memor...The distinctive feature of the adaptive immune system is its ability to generate immunological memory that can provide defense against subsequent infections.In the case of antibody-mediated immune responses,this memory comes in two cellular forms:plasma cells(PCs)and memory B cells(MBCs).PCs protect against reinfection by constitutively producing antibodies.The presence of a diverse pool of MBCs,which can expand and differentiate into PCs in secondary immune responses,is thought to be particularly important for defense against new pathogen variants.Recent studies have shown that the MBC compartment is far more heterogeneous than previously anticipated.This heterogeneity,among other factors,is shaped by their developmental pathway(germinal center(GC)vs non-GC-derived MBCs),the duration and strength of antigenic stimulation,anatomical and microanatomical localization,and the timing of generation in ontogeny.Combinations of these“layers”of MBC identities can define MBCs’properties and their fate in recall responses.Here,we review the mechanisms underlying MBC differentiation,maintenance,and reactivation and explore how the layered identity of MBCs contributes to the functions of these cells.展开更多
Aerobic exercise facilitates synaptic plasticity,thereby improving cognitive functions such as learning and memory.The 5-hydroxytryptamine system has been indicated in these processes.5-Hydroxytryptamine type 3 recept...Aerobic exercise facilitates synaptic plasticity,thereby improving cognitive functions such as learning and memory.The 5-hydroxytryptamine system has been indicated in these processes.5-Hydroxytryptamine type 3 receptors are necessary for exercise-induced hippocampal neurogenesis.Some antipsychotic drugs with 5-hydroxytryptamine type 3 receptor antagonistic properties may impede the amelioration of cognitive impairment and hippocampal plasticity induced by exercise.However,the mechanisms underlying the facilitation of synaptic plasticity by aerobic exercise have not yet been elucidated.In this study,we found that 5-hydroxytryptamine type 3 receptors played an important role in aerobic exercise-mediated improvement of hippocampal-dependent spatial and exploratory memory in mice.While 5-hydroxytryptamine type 3 receptors did not affect baseline neurogenesis in the hippocampal dentate gyrus,5-hydroxytryptamine type 3 receptors were required for aerobic exercise-induced neurogenesis and astrocyte proliferation in this region.In addition,5-hydroxytryptamine type 3 receptors were crucial for maintaining long-term potentiation in the CA1,dentate gyrus,and CA3 regions of the hippocampus.The long-term potentiation changes induced by aerobic exercise in sub-regions of the hippocampus were heterogeneous:5-hydroxytryptamine type 3 receptors were essential for aerobic exercise to enhance long-term potentiation in the CA3,but not the CA1 or dentate gyrus,regions of the hippocampus.Furthermore,aerobic exercise up-regulated 5-hydroxytryptamine type 3 receptor expression and increased brain-derived neurotrophic factor release in the hippocampus in a 5-hydroxytryptamine type 3 receptor-dependent manner.These results suggest that aerobic exercise increases hippocampal dentate gyrus neurogenesis and astrocyte proliferation via the up-regulation of 5-hydroxytryptamine type 3 receptors,leading to more brain-derived neurotrophic factor production and release from these cells,which results in long-term potentiation facilitation in the hippocampal CA3 region and help improve memory.Our findings provide insight into the mechanisms by which physical activity enhances memory and may have implications for improving memory through modulating 5-hydroxytryptamine type 3 receptor.展开更多
Near-infrared(NIR)light-responsive shape memory polymers(SMPs)show great promise for biomedical applications,but conventional photothermal agents suffer from high cost,complex preparation,or poor biocompatibility,whil...Near-infrared(NIR)light-responsive shape memory polymers(SMPs)show great promise for biomedical applications,but conventional photothermal agents suffer from high cost,complex preparation,or poor biocompatibility,while lignin-based alternatives exhibit insufficient photothermal conversion efficiency.Herein,we developed a novel strategy to enhance photothermal performance of lignin through sequential demethylation modification and Fe^(3+)complexation for constructing NIR light responsive SMPs.Dealkaline lignin(DL)was first demethylated using iodocyclohexane to produce demethylated lignin(DDL)with increased catechol content,which was then incorporated into polycaprolactone-based polyurethane synthesis followed by Fe^(3+)complexation.Results showed that DDL-Fe^(3+)complexes have significantly enhanced photothermal conversion performance,and the resulting PU-DDL+Fe^(3+)polyurethane with 0.5 wt%DDL content demonstrated a temperature increases of 39.8℃under 0.33 W·cm-2808 nm NIR irradiation.This excellent photothermal performance enables the shape-fixed PU-DDL+Fe^(3+)polyurethane to rapidly recover to its initial shape under NIR light irradiation.Additionally,PU-DDL+Fe^(3+)polyurethane exhibits good mechanical properties and biocompatibility,demonstrating significant biomedical application potential.展开更多
The goal of this paper is to investigate the long-time dynamics of solutions to a Kirchhoff type suspension bridge equation with nonlinear damping and memory term.For this problem we establish the well-posedness and e...The goal of this paper is to investigate the long-time dynamics of solutions to a Kirchhoff type suspension bridge equation with nonlinear damping and memory term.For this problem we establish the well-posedness and existence of uniform attractor under some suitable assumptions on the nonlinear term g(u),the nonlinear damping f(u_(t))and the external force h(x,t).Specifically,the asymptotic compactness of the semigroup is verified by the energy reconstruction method.展开更多
GABA_(A) receptors containingα5-subunits(GABA_(A)R-α5)cluster at both extrasynaptic and synaptic locations,interacting with the scaffold proteins radixin and gephyrin,respectively,and the re-localization of GABA_(A...GABA_(A) receptors containingα5-subunits(GABA_(A)R-α5)cluster at both extrasynaptic and synaptic locations,interacting with the scaffold proteins radixin and gephyrin,respectively,and the re-localization of GABA_(A)R-α5 influences GABAergic transmission.Here,we found that when early spatial memory deficits occurred in aged mice at 24 h after sevoflurane anesthesia,there was a re-localization of GABA_(A)R-α5 that enhanced tonic inhibition and reduced the decay kinetics of miniature inhibitory postsynaptic currents in the hippocampal CA1 region.Mechanistically,increased phosphorylation of radixin at threonine 564(Thr564)mediates the re-localization of GABA_(A)R-α5.Acute treatment with the selective extrasynaptic GABA_(A)R-α5 antagonist S44819 restored the GABA_(A)R-α5-mediated inhibitory currents by reversing radixin phosphorylation-dependent GABA_(A)R-α5 re-localization,then improved the sevoflurane-induced spatial memory impairment in aged mice.Our results suggest that the localization of GABA_(A)R-α5 altered by sevoflurane is linked to unbalanced GABAergic transmission,which induces early memory impairment in aged mice.Modulating the GABA_(A)R-α5 localization might be a novel strategy to improve memory after sevoflurane exposure.展开更多
Oxide semiconductors(OSs),introduced by the Hosono group in the early 2000s,have evolved from display backplane materials to promising candidates for advanced memory and logic devices.The exceptionally low leakage cur...Oxide semiconductors(OSs),introduced by the Hosono group in the early 2000s,have evolved from display backplane materials to promising candidates for advanced memory and logic devices.The exceptionally low leakage current of OSs and compatibility with three-dimensional(3D)architectures have recently sparked renewed interest in their use in semiconductor applications.This review begins by exploring the unique material properties of OSs,which fundamentally originate from their distinct electronic band structure.Subsequently,we focus on atomic layer deposition(ALD),a core technique for growing excellent OS films,covering both basic and advanced processes compatible with 3D scaling.The basic surface reaction mechanisms—adsorption and reaction—and their roles in film growth are introduced.Furthermore,material design strategies,such as cation selection,crystallinity control,anion doping,and heterostructure engineering,are discussed.We also highlight challenges in memory applications,including contact resistance,hydrogen instability,and lack of p-type materials,and discuss the feasibility of ALD-grown OSs as potential solutions.Lastly,we provide an outlook on the role of ALD-grown OSs in memory technologies.This review bridges material fundamentals and device-level requirements,offering a comprehensive perspective on the potential of ALD-driven OSs for next-generation semiconductor memory devices.展开更多
FeMnSi-based shape memory alloys(SMAs)have great applied potential to large-scale structures in civil engineering,especially as an aseismic structural material.Low-cycle fatigue performance is one of the most importan...FeMnSi-based shape memory alloys(SMAs)have great applied potential to large-scale structures in civil engineering,especially as an aseismic structural material.Low-cycle fatigue performance is one of the most important properties of FeMnSi-based SMA aseismic materials.However,the low-cycle fatigue behavior of such SMAs,especially the stress-controlled low-cycle fatigue behavior(with ratchetting effect),has not been clearly understood.In this work,the low-cycle fatigue behavior of the FeMnSiCrNi SMAs subjected to stress-controlled cyclic tension–compression loads is investigated,and the effects of temperature,loading frequency,stress amplitude,and stress ratio are addressed.By analyzing the cyclic stress–strain response,fatigue fracture surface morphology,dissipation energy,ratchetting strain,and equivalent damping ratio,the mechanisms behind the temperature-,loading frequency-,stress amplitude-,and stress ratio-dependent low-cycle fatigue behavior are discussed.The results show that the plasticity,martensitic transformation,and/or the ratchetting strain caused by their tension–compression asymmetry are the decisive factors affecting the low-cycle fatigue behavior of FeMnSiCrNi SMAs.展开更多
The highly dynamic nature,strong uncertainty,and coupled multiple safety constraints inherent in carrier aircraft recovery operations pose severe challenges for real-time decision-making.Addressing bolter scenarios,th...The highly dynamic nature,strong uncertainty,and coupled multiple safety constraints inherent in carrier aircraft recovery operations pose severe challenges for real-time decision-making.Addressing bolter scenarios,this study proposes an intelligent decision-making framework based on a deep long short-term memory Q-network.This framework transforms the real-time sequencing for bolter recovery problem into a partially observable Markov decision process.It employs a stacked long shortterm memory network to accurately capture the long-range temporal dependencies of bolter event chains and fuel consumption.Furthermore,it integrates a prioritized experience replay training mechanism to construct a safe and adaptive scheduling system capable of millisecond-level real-time decision-making.Experimental demonstrates that,within large-scale mass recovery scenarios,the framework achieves zero safety violations in static environments and maintains a fuel safety violation rate below 10%in dynamic scenarios,with single-step decision times at the millisecond level.The model exhibits strong generalization capability,effectively responding to unforeseen emergent situations—such as multiple bolters and fuel emergencies—without requiring retraining.This provides robust support for efficient carrier-based aircraft recovery operations.展开更多
Shape memory polymers used in 4D printing only had one permanent shape after molding,which limited their applications in requiring multiple reconstructions and multifunctional shapes.Furthermore,the inherent stability...Shape memory polymers used in 4D printing only had one permanent shape after molding,which limited their applications in requiring multiple reconstructions and multifunctional shapes.Furthermore,the inherent stability of the triazine ring structure within cyanate ester(CE)crosslinked networks after molding posed significant challenges for both recycling,repairing,and degradation of resin.To address these obstacles,dynamic thiocyanate ester(TCE)bonds and photocurable group were incorporated into CE,obtaining the recyclable and 3D printable CE covalent adaptable networks(CANs),denoted as PTCE1.5.This material exhibits a Young's modulus of 810 MPa and a tensile strength of 50.8 MPa.Notably,damaged printed PTCE1.5 objects can be readily repaired through reprinting and interface rejoining by thermal treatment.Leveraging the solid-state plasticity,PTCE1.5 also demonstrated attractive shape memory ability and permanent shape reconfigurability,enabling its reconfigurable 4D printing.The printed PTCE1.5 hinges and a main body were assembled into a deployable and retractable satellite model,validating its potential application as a controllable component in the aerospace field.Moreover,printed PTCE1.5 can be fully degraded into thiol-modified intermediate products.Overall,this material not only enriches the application range of CE resin,but also provides a reliable approach to addressing environmental issue.展开更多
Programmable/reprogrammable magneto-responsive composites(MRCs)are highly desirable for applications in soft robotics,morphable actuators,and biomedical devices due to their capabilities of undergoing reversible,compl...Programmable/reprogrammable magneto-responsive composites(MRCs)are highly desirable for applications in soft robotics,morphable actuators,and biomedical devices due to their capabilities of undergoing reversible,complex,untethered,and rapid deformations.However,current MRC-based devices primarily rely on soft matrices,which revert to their original shapes and cease functioning when external magnetic fields are removed.Moreover,their magnetization programming,deformations,and functioning need to alternate between encoding and actuation platforms,limiting the adaptability and efficiency.Here,we present a reprogrammable magnetic shape-memory composite(RM-SMC)integrating a shape-memory polymer(SMP)skeleton with phase-transition magnetic microcapsules.High-intensity laser melts microcapsules for magnetic realignment under programmed fields,while low-intensity laser softens SMP for structural reconfiguration without compromising integrity.This dual-laser strategy facilitates in situ magnetization programming,shape morphing,and function execution within a single material system.Our innovative approach enables unique applications,including omnidirectional multi-degree-of-freedom actuators that can activate light switches,solar trackers that optimize energy capture,and adaptive impellers that modulate fluid pumping.By eliminating platform alternation and enabling shape/function retention post-actuation,the RM-SMC platform overcomes critical limitations in conventional MRCs,establishing a paradigm for multifunctional devices requiring persistent configuration control and field-independent operation.展开更多
New electronic devices based on the physical properties of electrically driven skyrmions are promising for logic computing and nonvolatile memory applications.However,achieving efficient and practical compute-storage ...New electronic devices based on the physical properties of electrically driven skyrmions are promising for logic computing and nonvolatile memory applications.However,achieving efficient and practical compute-storage integration remains challenging owing to the structural complexity,limited functionality,and low flexibility observed in most skyrmion-based devices.In this study,we designed a novel device architecture that integrates seven basic logic gates into a unified physical structure.Their operation can be enabled by physical mechanisms,such as spin-orbit torque,spin-transfer torque,skyrmion-edge repulsions,and skyrmion-skyrmion interactions.Furthermore,by incorporating voltage-controlled magnetic anisotropy,the device achieved multi-input capability and reconfigurability functionality.Ultralow power consumption(<1 fJ/bit per logic function)and extremely high logic density were achieved.Significantly,the compatibility of this nanotrack design with existing skyrmion racetrack memory paves the way for advanced in-memory computing in spintronic architectures.展开更多
Read-write dependency is an important factor restricting software efficiency.Timing Speculative(TS)is a processing architecture aiming to improve energy efficiency of microprocessors.Timing error rate,influenced by th...Read-write dependency is an important factor restricting software efficiency.Timing Speculative(TS)is a processing architecture aiming to improve energy efficiency of microprocessors.Timing error rate,influenced by the read-write dependency,bottlenecks the voltage down-scaling and so the energy efficiency of TS processors.We proposed a method called Read-Write Dependency Aware Register Allocation.It is based on the Read-Write Dependency aware Interference Graph(RWDIG)conception.Registers are reallocated to loosen the read-write dependencies,so resulting in a reduction of timing errors.The traditional no operation(Nop)padding method is also redesigned to increase the distance value to above 2.We analyzed the dependencies of registers and maximized the average distance value of read and write dependencies.Experimental results showed that we can reduce all read-write dependency by Nop padding,as well as the overhead timing errors.An energy saving of approximately 7%was achieved.展开更多
Photonic platforms are gradually emerging as a promising option to encounter the ever-growing demand for artificial intelligence,among which photonic time-delay reservoir computing(TDRC)is widely anticipated.While suc...Photonic platforms are gradually emerging as a promising option to encounter the ever-growing demand for artificial intelligence,among which photonic time-delay reservoir computing(TDRC)is widely anticipated.While such a computing paradigm can only employ a single photonic device as the nonlinear node for data processing,the performance highly relies on the fading memory provided by the delay feedback loop(FL),which sets a restriction on the extensibility of physical implementation,especially for highly integrated chips.Here,we present a simplified photonic scheme for more flexible parameter configurations leveraging the designed quasi-convolution coding(QC),which completely gets rid of the dependence on FL.Unlike delay-based TDRC,encoded data in QC-based RC(QRC)enables temporal feature extraction,facilitating augmented memory capabilities.Thus,our proposed QRC is enabled to deal with time-related tasks or sequential data without the implementation of FL.Furthermore,we can implement this hardware with a low-power,easily integrable vertical-cavity surface-emitting laser for high-performance parallel processing.We illustrate the concept validation through simulation and experimental comparison of QRC and TDRC,wherein the simpler-structured QRC outperforms across various benchmark tasks.Our results may underscore an auspicious solution for the hardware implementation of deep neural networks.展开更多
Hippocampal neuronal loss causes cognitive dysfunction in Alzheimer’s disease.Adult hippocampal neurogenesis is reduced in patients with Alzheimer’s disease.Exercise stimulates adult hippocampal neurogenesis in rode...Hippocampal neuronal loss causes cognitive dysfunction in Alzheimer’s disease.Adult hippocampal neurogenesis is reduced in patients with Alzheimer’s disease.Exercise stimulates adult hippocampal neurogenesis in rodents and improves memory and slows cognitive decline in patients with Alzheimer’s disease.However,the molecular pathways for exercise-induced adult hippocampal neurogenesis and improved cognition in Alzheimer’s disease are poorly understood.Recently,regulator of G protein signaling 6(RGS6)was identified as the mediator of voluntary running-induced adult hippocampal neurogenesis in mice.Here,we generated novel RGS6fl/fl;APP_(SWE) mice and used retroviral approaches to examine the impact of RGS6 deletion from dentate gyrus neuronal progenitor cells on voluntary running-induced adult hippocampal neurogenesis and cognition in an amyloid-based Alzheimer’s disease mouse model.We found that voluntary running in APP_(SWE) mice restored their hippocampal cognitive impairments to that of control mice.This cognitive rescue was abolished by RGS6 deletion in dentate gyrus neuronal progenitor cells,which also abolished running-mediated increases in adult hippocampal neurogenesis.Adult hippocampal neurogenesis was reduced in sedentary APP_(SWE) mice versus control mice,with basal adult hippocampal neurogenesis reduced by RGS6 deletion in dentate gyrus neural precursor cells.RGS6 was expressed in neurons within the dentate gyrus of patients with Alzheimer’s disease with significant loss of these RGS6-expressing neurons.Thus,RGS6 mediated voluntary running-induced rescue of impaired cognition and adult hippocampal neurogenesis in APP_(SWE) mice,identifying RGS6 in dentate gyrus neural precursor cells as a possible therapeutic target in Alzheimer’s disease.展开更多
The active development of space industry necessitates the cre-ation of novel materials with unique properties,including shape memory alloys(SMAs).The development of ultra-high temperature SMAs(UHTSMAs)with operating t...The active development of space industry necessitates the cre-ation of novel materials with unique properties,including shape memory alloys(SMAs).The development of ultra-high temperature SMAs(UHTSMAs)with operating temperatures above 400℃is a significant challenge[1-3].It is known that reversible thermoelas-tic martensitic transformation(MT)is the basis for shape mem-ory behavior[4].Currently,there are several systems in which MT temperatures meet the above requirements,for example,RuNb[5],HfPd[6],TiPd[7].展开更多
BACKGROUND Fear-related disorders,such as post-traumatic stress disorder(PTSD),significantly impact patients and families.Exposure therapy is a common treatment,but imp-roving its effectiveness remains a key challenge...BACKGROUND Fear-related disorders,such as post-traumatic stress disorder(PTSD),significantly impact patients and families.Exposure therapy is a common treatment,but imp-roving its effectiveness remains a key challenge.Fear conditioning and extinction in animal models offer insights into its mechanisms.Our previous research indi-cates that DNA methyltransferases play a role in fear memory renewal.AIM To investigate the role of DNA methylation in the extinction of fear memory,with the goal of identifying potential strategies to enhance the efficacy of exposure therapy for fear-related disorders.METHODS This study investigated the role of DNA methylation in fear memory extinction in mice.DNA methylation was manipulated using N-phthalyl-L-tryptophan(RG108)to reduce methylation and L-methionine injections to enhance it.Neuronal activity,and dendritic spine density was measured following extinction training.RESULTS RG108 suppressed extinction,reduced spine density,and inhibited neuronal activity.Methionine injections facilitated extinction.CONCLUSION DNA methylation is crucial for fear memory extinction.Enhancing methylation may improve the efficacy of exposure therapy,offering a potential strategy to treat fear-related disorders.展开更多
The constitutive models of shape memory alloys(SMAs)play an important role in facilitating the widespread application of such types of alloys in various engineering fields.However,to accurately describe the deformatio...The constitutive models of shape memory alloys(SMAs)play an important role in facilitating the widespread application of such types of alloys in various engineering fields.However,to accurately describe the deformation behaviors of SMAs,the concepts in classical plasticity are employed in the existing constitutive models,and a series of complex mathematical equations are involved.Such complexity brings inconvenience for the construction,implementation,and application of the constitutive models.To overcome these shortcomings,a data-driven constitutive model of SMAs is developed in this work based on the artificial neural network(ANN).In the proposed model,the components of the strain tensor in principal space,ambient temperature,and the maximum equivalent strain in the deformation history from the initial state to the current loading state are chosen as the input features,and the components of the stress tensor in principal space are set as the output.The proposed ANN-based constitutive model is implemented into the finite element program ABAQUS by deriving its consistent tangent modulus and writing a user-defined material subroutine.The stress-strain responses of SMA material under various loading paths and at different ambient temperatures are used to train the ANN model,which is generated from the existing constitutive model(numerical experiments).To validate the capability of the proposed model,the predicted stress-strain responses of SMA material,and the global and local responses of two typical SMA structures are compared with the corresponding numerical experiments.This work demonstrates a good potential to obtain the constitutive model of SMAs by pure data and avoid the need for vast stores of knowledge for the construction of constitutive models.展开更多
基金Supported by National Natural Science Foundation of China Under Grant(12401647)Supported by Fundamental Research Program of Shanxi Province(202203021212336)+2 种基金Taiyuan Institute of Technology Scientific Research Initial Funding(2023KJ057,2024KJ007,2024LJ005)Supported by Scientific and Technologial Innovation Programs of Higher Education Institutions in Shanxi(2024L358)Youth Program of Taiyuan University(24TYQN10)。
文摘The main purpose of this paper is to investigate the singularities of solutions to the single Tricomi equation with derivative term and combined memory term.In addition,the blow-up of the solution to the weakly coupled system with memory term is also considered,where one is a power nonlinear term and the other is a derivative nonlinear term.Upper bound lifespan estimates of solution are obtained in the sub-critical by utilizing the test function method and iteration technique.The innovation of this paper focuses on the lifespan estimates of the solutions,which extends the well-known Strauss and Glassey conjectures.
基金Our laboratory is supported by grants from the Swedish Research Council(2021-01468)Cancerfonden(211602 Pj and 243516 Pj)+2 种基金Barncancerfonden(PR2023-0091)Radiumhemmets Forskningsfonder(231233)the Knut and Alice Wallenberg Foundation(KAW 2024.0097).
文摘The distinctive feature of the adaptive immune system is its ability to generate immunological memory that can provide defense against subsequent infections.In the case of antibody-mediated immune responses,this memory comes in two cellular forms:plasma cells(PCs)and memory B cells(MBCs).PCs protect against reinfection by constitutively producing antibodies.The presence of a diverse pool of MBCs,which can expand and differentiate into PCs in secondary immune responses,is thought to be particularly important for defense against new pathogen variants.Recent studies have shown that the MBC compartment is far more heterogeneous than previously anticipated.This heterogeneity,among other factors,is shaped by their developmental pathway(germinal center(GC)vs non-GC-derived MBCs),the duration and strength of antigenic stimulation,anatomical and microanatomical localization,and the timing of generation in ontogeny.Combinations of these“layers”of MBC identities can define MBCs’properties and their fate in recall responses.Here,we review the mechanisms underlying MBC differentiation,maintenance,and reactivation and explore how the layered identity of MBCs contributes to the functions of these cells.
基金supported by the National Natural Science Foundation of China,Nos.31972914,31771175(both to YH).
文摘Aerobic exercise facilitates synaptic plasticity,thereby improving cognitive functions such as learning and memory.The 5-hydroxytryptamine system has been indicated in these processes.5-Hydroxytryptamine type 3 receptors are necessary for exercise-induced hippocampal neurogenesis.Some antipsychotic drugs with 5-hydroxytryptamine type 3 receptor antagonistic properties may impede the amelioration of cognitive impairment and hippocampal plasticity induced by exercise.However,the mechanisms underlying the facilitation of synaptic plasticity by aerobic exercise have not yet been elucidated.In this study,we found that 5-hydroxytryptamine type 3 receptors played an important role in aerobic exercise-mediated improvement of hippocampal-dependent spatial and exploratory memory in mice.While 5-hydroxytryptamine type 3 receptors did not affect baseline neurogenesis in the hippocampal dentate gyrus,5-hydroxytryptamine type 3 receptors were required for aerobic exercise-induced neurogenesis and astrocyte proliferation in this region.In addition,5-hydroxytryptamine type 3 receptors were crucial for maintaining long-term potentiation in the CA1,dentate gyrus,and CA3 regions of the hippocampus.The long-term potentiation changes induced by aerobic exercise in sub-regions of the hippocampus were heterogeneous:5-hydroxytryptamine type 3 receptors were essential for aerobic exercise to enhance long-term potentiation in the CA3,but not the CA1 or dentate gyrus,regions of the hippocampus.Furthermore,aerobic exercise up-regulated 5-hydroxytryptamine type 3 receptor expression and increased brain-derived neurotrophic factor release in the hippocampus in a 5-hydroxytryptamine type 3 receptor-dependent manner.These results suggest that aerobic exercise increases hippocampal dentate gyrus neurogenesis and astrocyte proliferation via the up-regulation of 5-hydroxytryptamine type 3 receptors,leading to more brain-derived neurotrophic factor production and release from these cells,which results in long-term potentiation facilitation in the hippocampal CA3 region and help improve memory.Our findings provide insight into the mechanisms by which physical activity enhances memory and may have implications for improving memory through modulating 5-hydroxytryptamine type 3 receptor.
基金supported by the National Natural Science Foundation of China(Nos.51603005,52403186 and 52573150)Fujian Provincial Natural Science Foundation of China(No.2024J011447)+1 种基金Natural Science Foundation of Xiamen,China(No.3502Z20227305)the Postdoctoral Fellowship Program of CPSF(No.GZC20240095)。
文摘Near-infrared(NIR)light-responsive shape memory polymers(SMPs)show great promise for biomedical applications,but conventional photothermal agents suffer from high cost,complex preparation,or poor biocompatibility,while lignin-based alternatives exhibit insufficient photothermal conversion efficiency.Herein,we developed a novel strategy to enhance photothermal performance of lignin through sequential demethylation modification and Fe^(3+)complexation for constructing NIR light responsive SMPs.Dealkaline lignin(DL)was first demethylated using iodocyclohexane to produce demethylated lignin(DDL)with increased catechol content,which was then incorporated into polycaprolactone-based polyurethane synthesis followed by Fe^(3+)complexation.Results showed that DDL-Fe^(3+)complexes have significantly enhanced photothermal conversion performance,and the resulting PU-DDL+Fe^(3+)polyurethane with 0.5 wt%DDL content demonstrated a temperature increases of 39.8℃under 0.33 W·cm-2808 nm NIR irradiation.This excellent photothermal performance enables the shape-fixed PU-DDL+Fe^(3+)polyurethane to rapidly recover to its initial shape under NIR light irradiation.Additionally,PU-DDL+Fe^(3+)polyurethane exhibits good mechanical properties and biocompatibility,demonstrating significant biomedical application potential.
基金Supported by the National Natural Science Foundation of China(Grant Nos.11961059,1210502)the University Innovation Project of Gansu Province(Grant No.2023B-062)the Gansu Province Basic Research Innovation Group Project(Grant No.23JRRA684).
文摘The goal of this paper is to investigate the long-time dynamics of solutions to a Kirchhoff type suspension bridge equation with nonlinear damping and memory term.For this problem we establish the well-posedness and existence of uniform attractor under some suitable assumptions on the nonlinear term g(u),the nonlinear damping f(u_(t))and the external force h(x,t).Specifically,the asymptotic compactness of the semigroup is verified by the energy reconstruction method.
基金supported by the Tianjin Scientific Research Start-up Foundation for Talent Introduction(2021-1-10)the 14th Five-Year Plan Peak Discipline Support Plan of Tianjin Medical University Cancer Institute and Hospital(7-2-13)+3 种基金National Natural Science Foundation of China(82171221),Beijing Bethune Charitable Foundation(YXJL-2024-0778-0030)Beijing Science and Technology Innovation Medical Development Foundation(KC2024-JF-0069)Tianjin Medical University Postgraduate Education Reform Research Program(TMUYY02)Tianjin Key Medical Discipline(Specialty)Construction(TJYXZDXK-009A).
文摘GABA_(A) receptors containingα5-subunits(GABA_(A)R-α5)cluster at both extrasynaptic and synaptic locations,interacting with the scaffold proteins radixin and gephyrin,respectively,and the re-localization of GABA_(A)R-α5 influences GABAergic transmission.Here,we found that when early spatial memory deficits occurred in aged mice at 24 h after sevoflurane anesthesia,there was a re-localization of GABA_(A)R-α5 that enhanced tonic inhibition and reduced the decay kinetics of miniature inhibitory postsynaptic currents in the hippocampal CA1 region.Mechanistically,increased phosphorylation of radixin at threonine 564(Thr564)mediates the re-localization of GABA_(A)R-α5.Acute treatment with the selective extrasynaptic GABA_(A)R-α5 antagonist S44819 restored the GABA_(A)R-α5-mediated inhibitory currents by reversing radixin phosphorylation-dependent GABA_(A)R-α5 re-localization,then improved the sevoflurane-induced spatial memory impairment in aged mice.Our results suggest that the localization of GABA_(A)R-α5 altered by sevoflurane is linked to unbalanced GABAergic transmission,which induces early memory impairment in aged mice.Modulating the GABA_(A)R-α5 localization might be a novel strategy to improve memory after sevoflurane exposure.
基金supported by National Research Foundation of Korea(NRF)funded by Ministry of Science and ICT(MSIT)(No.RS-2023-00260527,RS-2024-00407282,RS-2025-00557667)supported by Hanyang University Industry-University Cooperation Foundation(No.202400000003943)supported by Korea Planning&Evaluation Institute of Industrial Technology(KEIT)funded by South Korean Ministry of Trade,Industry and Energy(MOTIE)(No.RS-2025-25454815,RS-2025-02308064,20017382)。
文摘Oxide semiconductors(OSs),introduced by the Hosono group in the early 2000s,have evolved from display backplane materials to promising candidates for advanced memory and logic devices.The exceptionally low leakage current of OSs and compatibility with three-dimensional(3D)architectures have recently sparked renewed interest in their use in semiconductor applications.This review begins by exploring the unique material properties of OSs,which fundamentally originate from their distinct electronic band structure.Subsequently,we focus on atomic layer deposition(ALD),a core technique for growing excellent OS films,covering both basic and advanced processes compatible with 3D scaling.The basic surface reaction mechanisms—adsorption and reaction—and their roles in film growth are introduced.Furthermore,material design strategies,such as cation selection,crystallinity control,anion doping,and heterostructure engineering,are discussed.We also highlight challenges in memory applications,including contact resistance,hydrogen instability,and lack of p-type materials,and discuss the feasibility of ALD-grown OSs as potential solutions.Lastly,we provide an outlook on the role of ALD-grown OSs in memory technologies.This review bridges material fundamentals and device-level requirements,offering a comprehensive perspective on the potential of ALD-driven OSs for next-generation semiconductor memory devices.
基金The National Natural Science Foundation of China(12202294)the Sichuan Science and Technology Program(2024NSFSC1346)are acknowledged.
文摘FeMnSi-based shape memory alloys(SMAs)have great applied potential to large-scale structures in civil engineering,especially as an aseismic structural material.Low-cycle fatigue performance is one of the most important properties of FeMnSi-based SMA aseismic materials.However,the low-cycle fatigue behavior of such SMAs,especially the stress-controlled low-cycle fatigue behavior(with ratchetting effect),has not been clearly understood.In this work,the low-cycle fatigue behavior of the FeMnSiCrNi SMAs subjected to stress-controlled cyclic tension–compression loads is investigated,and the effects of temperature,loading frequency,stress amplitude,and stress ratio are addressed.By analyzing the cyclic stress–strain response,fatigue fracture surface morphology,dissipation energy,ratchetting strain,and equivalent damping ratio,the mechanisms behind the temperature-,loading frequency-,stress amplitude-,and stress ratio-dependent low-cycle fatigue behavior are discussed.The results show that the plasticity,martensitic transformation,and/or the ratchetting strain caused by their tension–compression asymmetry are the decisive factors affecting the low-cycle fatigue behavior of FeMnSiCrNi SMAs.
基金supported by the National Natural Science Foundation of China(Grant No.62403486)。
文摘The highly dynamic nature,strong uncertainty,and coupled multiple safety constraints inherent in carrier aircraft recovery operations pose severe challenges for real-time decision-making.Addressing bolter scenarios,this study proposes an intelligent decision-making framework based on a deep long short-term memory Q-network.This framework transforms the real-time sequencing for bolter recovery problem into a partially observable Markov decision process.It employs a stacked long shortterm memory network to accurately capture the long-range temporal dependencies of bolter event chains and fuel consumption.Furthermore,it integrates a prioritized experience replay training mechanism to construct a safe and adaptive scheduling system capable of millisecond-level real-time decision-making.Experimental demonstrates that,within large-scale mass recovery scenarios,the framework achieves zero safety violations in static environments and maintains a fuel safety violation rate below 10%in dynamic scenarios,with single-step decision times at the millisecond level.The model exhibits strong generalization capability,effectively responding to unforeseen emergent situations—such as multiple bolters and fuel emergencies—without requiring retraining.This provides robust support for efficient carrier-based aircraft recovery operations.
基金supported by the National Natural Science Foundation of China(Nos.52473080,52403167 and 52173079)the Fundamental Research Funds for the Central Universities(Nos.xtr052023001 and xzy012023037)+1 种基金the Postdoctoral Research Project of Shaanxi Province(No.2024BSHSDZZ054)the Shaanxi Laboratory of Advanced Materials(No.2024ZY-JCYJ-04-12).
文摘Shape memory polymers used in 4D printing only had one permanent shape after molding,which limited their applications in requiring multiple reconstructions and multifunctional shapes.Furthermore,the inherent stability of the triazine ring structure within cyanate ester(CE)crosslinked networks after molding posed significant challenges for both recycling,repairing,and degradation of resin.To address these obstacles,dynamic thiocyanate ester(TCE)bonds and photocurable group were incorporated into CE,obtaining the recyclable and 3D printable CE covalent adaptable networks(CANs),denoted as PTCE1.5.This material exhibits a Young's modulus of 810 MPa and a tensile strength of 50.8 MPa.Notably,damaged printed PTCE1.5 objects can be readily repaired through reprinting and interface rejoining by thermal treatment.Leveraging the solid-state plasticity,PTCE1.5 also demonstrated attractive shape memory ability and permanent shape reconfigurability,enabling its reconfigurable 4D printing.The printed PTCE1.5 hinges and a main body were assembled into a deployable and retractable satellite model,validating its potential application as a controllable component in the aerospace field.Moreover,printed PTCE1.5 can be fully degraded into thiol-modified intermediate products.Overall,this material not only enriches the application range of CE resin,but also provides a reliable approach to addressing environmental issue.
基金supported by the National Natural Science Foundation of China(Nos.52075516,61927814,62325507,and 52122511)the National Key Research and Development Program of China(No.2021YFF0502700)+2 种基金the Major Scientific and Technological Projects in Anhui Province(202103a05020005,202203a05020014)the Students’Innovation and Entrepreneurship Foundation of USTC(CY2022G09)the Hefei Municipal Natural Science Foundation(No.HZR2450)。
文摘Programmable/reprogrammable magneto-responsive composites(MRCs)are highly desirable for applications in soft robotics,morphable actuators,and biomedical devices due to their capabilities of undergoing reversible,complex,untethered,and rapid deformations.However,current MRC-based devices primarily rely on soft matrices,which revert to their original shapes and cease functioning when external magnetic fields are removed.Moreover,their magnetization programming,deformations,and functioning need to alternate between encoding and actuation platforms,limiting the adaptability and efficiency.Here,we present a reprogrammable magnetic shape-memory composite(RM-SMC)integrating a shape-memory polymer(SMP)skeleton with phase-transition magnetic microcapsules.High-intensity laser melts microcapsules for magnetic realignment under programmed fields,while low-intensity laser softens SMP for structural reconfiguration without compromising integrity.This dual-laser strategy facilitates in situ magnetization programming,shape morphing,and function execution within a single material system.Our innovative approach enables unique applications,including omnidirectional multi-degree-of-freedom actuators that can activate light switches,solar trackers that optimize energy capture,and adaptive impellers that modulate fluid pumping.By eliminating platform alternation and enabling shape/function retention post-actuation,the RM-SMC platform overcomes critical limitations in conventional MRCs,establishing a paradigm for multifunctional devices requiring persistent configuration control and field-independent operation.
基金support from the National Natural Science Foundation of China (Grant No.12474101)support from the National Natural Science Foundation of China (Grant Nos.52272202 and W2421027)support from the National Natural Science Foundation of China (Grant No.52501307)。
文摘New electronic devices based on the physical properties of electrically driven skyrmions are promising for logic computing and nonvolatile memory applications.However,achieving efficient and practical compute-storage integration remains challenging owing to the structural complexity,limited functionality,and low flexibility observed in most skyrmion-based devices.In this study,we designed a novel device architecture that integrates seven basic logic gates into a unified physical structure.Their operation can be enabled by physical mechanisms,such as spin-orbit torque,spin-transfer torque,skyrmion-edge repulsions,and skyrmion-skyrmion interactions.Furthermore,by incorporating voltage-controlled magnetic anisotropy,the device achieved multi-input capability and reconfigurability functionality.Ultralow power consumption(<1 fJ/bit per logic function)and extremely high logic density were achieved.Significantly,the compatibility of this nanotrack design with existing skyrmion racetrack memory paves the way for advanced in-memory computing in spintronic architectures.
基金This work was supported by the Project of Hunan Social Science Achievement Evaluation Committee(XSP20YBZ090,Sheng Xiao,2020).
文摘Read-write dependency is an important factor restricting software efficiency.Timing Speculative(TS)is a processing architecture aiming to improve energy efficiency of microprocessors.Timing error rate,influenced by the read-write dependency,bottlenecks the voltage down-scaling and so the energy efficiency of TS processors.We proposed a method called Read-Write Dependency Aware Register Allocation.It is based on the Read-Write Dependency aware Interference Graph(RWDIG)conception.Registers are reallocated to loosen the read-write dependencies,so resulting in a reduction of timing errors.The traditional no operation(Nop)padding method is also redesigned to increase the distance value to above 2.We analyzed the dependencies of registers and maximized the average distance value of read and write dependencies.Experimental results showed that we can reduce all read-write dependency by Nop padding,as well as the overhead timing errors.An energy saving of approximately 7%was achieved.
基金National Natural Science Foundation of China(62171305,62405206,62004135,62001317,62111530301)Natural Science Foundation of Jiangsu Province(BK20240778,BK20241917)+3 种基金State Key Laboratory of Advanced Optical Communication Systems and Networks,China(2023GZKF08)China Postdoctoral Science Foundation(2024M752314)Postdoctoral Fellowship Program of CPSF(GZC20231883)Innovative and Entrepreneurial Talent Program of Jiangsu Province(JSSCRC2021527).
文摘Photonic platforms are gradually emerging as a promising option to encounter the ever-growing demand for artificial intelligence,among which photonic time-delay reservoir computing(TDRC)is widely anticipated.While such a computing paradigm can only employ a single photonic device as the nonlinear node for data processing,the performance highly relies on the fading memory provided by the delay feedback loop(FL),which sets a restriction on the extensibility of physical implementation,especially for highly integrated chips.Here,we present a simplified photonic scheme for more flexible parameter configurations leveraging the designed quasi-convolution coding(QC),which completely gets rid of the dependence on FL.Unlike delay-based TDRC,encoded data in QC-based RC(QRC)enables temporal feature extraction,facilitating augmented memory capabilities.Thus,our proposed QRC is enabled to deal with time-related tasks or sequential data without the implementation of FL.Furthermore,we can implement this hardware with a low-power,easily integrable vertical-cavity surface-emitting laser for high-performance parallel processing.We illustrate the concept validation through simulation and experimental comparison of QRC and TDRC,wherein the simpler-structured QRC outperforms across various benchmark tasks.Our results may underscore an auspicious solution for the hardware implementation of deep neural networks.
基金supported by the National Institutes of Health,Nos.AA025919,AA025919-03S1,and AA025919-05S1(all to RAF).
文摘Hippocampal neuronal loss causes cognitive dysfunction in Alzheimer’s disease.Adult hippocampal neurogenesis is reduced in patients with Alzheimer’s disease.Exercise stimulates adult hippocampal neurogenesis in rodents and improves memory and slows cognitive decline in patients with Alzheimer’s disease.However,the molecular pathways for exercise-induced adult hippocampal neurogenesis and improved cognition in Alzheimer’s disease are poorly understood.Recently,regulator of G protein signaling 6(RGS6)was identified as the mediator of voluntary running-induced adult hippocampal neurogenesis in mice.Here,we generated novel RGS6fl/fl;APP_(SWE) mice and used retroviral approaches to examine the impact of RGS6 deletion from dentate gyrus neuronal progenitor cells on voluntary running-induced adult hippocampal neurogenesis and cognition in an amyloid-based Alzheimer’s disease mouse model.We found that voluntary running in APP_(SWE) mice restored their hippocampal cognitive impairments to that of control mice.This cognitive rescue was abolished by RGS6 deletion in dentate gyrus neuronal progenitor cells,which also abolished running-mediated increases in adult hippocampal neurogenesis.Adult hippocampal neurogenesis was reduced in sedentary APP_(SWE) mice versus control mice,with basal adult hippocampal neurogenesis reduced by RGS6 deletion in dentate gyrus neural precursor cells.RGS6 was expressed in neurons within the dentate gyrus of patients with Alzheimer’s disease with significant loss of these RGS6-expressing neurons.Thus,RGS6 mediated voluntary running-induced rescue of impaired cognition and adult hippocampal neurogenesis in APP_(SWE) mice,identifying RGS6 in dentate gyrus neural precursor cells as a possible therapeutic target in Alzheimer’s disease.
基金supported by the National Natural Science Foundation of China(Nos.52201207 and 52271169)the Fundamental Research Funds for the Central University(No.3072024LJ1002).
文摘The active development of space industry necessitates the cre-ation of novel materials with unique properties,including shape memory alloys(SMAs).The development of ultra-high temperature SMAs(UHTSMAs)with operating temperatures above 400℃is a significant challenge[1-3].It is known that reversible thermoelas-tic martensitic transformation(MT)is the basis for shape mem-ory behavior[4].Currently,there are several systems in which MT temperatures meet the above requirements,for example,RuNb[5],HfPd[6],TiPd[7].
基金Supported by National Natural Science Foundation of China,No.82360231Yunnan Basic Research Program General Project,No.202401AT070075+1 种基金Dali Basic Research Program Key Project,No.202301A020021Youth Special Project for Basic Research of Local Universities in Yunnan Province,No.202301BA070001-127.
文摘BACKGROUND Fear-related disorders,such as post-traumatic stress disorder(PTSD),significantly impact patients and families.Exposure therapy is a common treatment,but imp-roving its effectiveness remains a key challenge.Fear conditioning and extinction in animal models offer insights into its mechanisms.Our previous research indi-cates that DNA methyltransferases play a role in fear memory renewal.AIM To investigate the role of DNA methylation in the extinction of fear memory,with the goal of identifying potential strategies to enhance the efficacy of exposure therapy for fear-related disorders.METHODS This study investigated the role of DNA methylation in fear memory extinction in mice.DNA methylation was manipulated using N-phthalyl-L-tryptophan(RG108)to reduce methylation and L-methionine injections to enhance it.Neuronal activity,and dendritic spine density was measured following extinction training.RESULTS RG108 suppressed extinction,reduced spine density,and inhibited neuronal activity.Methionine injections facilitated extinction.CONCLUSION DNA methylation is crucial for fear memory extinction.Enhancing methylation may improve the efficacy of exposure therapy,offering a potential strategy to treat fear-related disorders.
基金supported by the National Natural Science Foundation of China(NSFC)(Grant No.12322203).
文摘The constitutive models of shape memory alloys(SMAs)play an important role in facilitating the widespread application of such types of alloys in various engineering fields.However,to accurately describe the deformation behaviors of SMAs,the concepts in classical plasticity are employed in the existing constitutive models,and a series of complex mathematical equations are involved.Such complexity brings inconvenience for the construction,implementation,and application of the constitutive models.To overcome these shortcomings,a data-driven constitutive model of SMAs is developed in this work based on the artificial neural network(ANN).In the proposed model,the components of the strain tensor in principal space,ambient temperature,and the maximum equivalent strain in the deformation history from the initial state to the current loading state are chosen as the input features,and the components of the stress tensor in principal space are set as the output.The proposed ANN-based constitutive model is implemented into the finite element program ABAQUS by deriving its consistent tangent modulus and writing a user-defined material subroutine.The stress-strain responses of SMA material under various loading paths and at different ambient temperatures are used to train the ANN model,which is generated from the existing constitutive model(numerical experiments).To validate the capability of the proposed model,the predicted stress-strain responses of SMA material,and the global and local responses of two typical SMA structures are compared with the corresponding numerical experiments.This work demonstrates a good potential to obtain the constitutive model of SMAs by pure data and avoid the need for vast stores of knowledge for the construction of constitutive models.
