Mitochondrial dysfunction and oxidative stress are widely regarded as primary drivers of aging and are associated with several neurodegenerative diseases.The degeneration of motor neurons during aging is a critical pa...Mitochondrial dysfunction and oxidative stress are widely regarded as primary drivers of aging and are associated with several neurodegenerative diseases.The degeneration of motor neurons during aging is a critical pathological factor contributing to the progression of sarcopenia.However,the morphological and functional changes in mitochondria and their interplay in the degeneration of the neuromuscular junction during aging remain poorly understood.A defined systematic search of the Pub Med,Web of Science and Embase databases(last accessed on October 30,2024)was conducted with search terms including'mitochondria','aging'and'NMJ'.Clinical and preclinical studies of mitochondrial dysfunction and neuromuscular junction degeneration during aging.Twentyseven studies were included in this systematic review.This systematic review provides a summary of morphological,functional and biological changes in neuromuscular junction,mitochondrial morphology,biosynthesis,respiratory chain function,and mitophagy during aging.We focus on the interactions and mechanisms underlying the relationship between mitochondria and neuromuscular junctions during aging.Aging is characterized by significant reductions in mitochondrial fusion/fission cycles,biosynthesis,and mitochondrial quality control,which may lead to neuromuscular junction dysfunction,denervation and poor physical performance.Motor nerve terminals that exhibit redox sensitivity are among the first to exhibit abnormalities,ultimately leading to an early decline in muscle strength through impaired neuromuscular junction transmission function.Parg coactivator 1 alpha is a crucial molecule that regulates mitochondrial biogenesis and modulates various pathways,including the mitochondrial respiratory chain,energy deficiency,oxidative stress,and inflammation.Mitochondrial dysfunction is correlated with neuromuscular junction denervation and acetylcholine receptor fragmentation,resulting in muscle atrophy and a decrease in strength during aging.Physical therapy,pharmacotherapy,and gene therapy can alleviate the structural degeneration and functional deterioration of neuromuscular junction by restoring mitochondrial function.Therefore,mitochondria are considered potential targets for preserving neuromuscular junction morphology and function during aging to treat sarcopenia.展开更多
Multiferroic tunnel junctions(MFTJs),which combine tunneling magnetoresistance(TMR)and electroresistance(TER)efects,have emerged as key candidates for data storage.Two-dimensional van der Waals(vdW)MFTJs,in particular...Multiferroic tunnel junctions(MFTJs),which combine tunneling magnetoresistance(TMR)and electroresistance(TER)efects,have emerged as key candidates for data storage.Two-dimensional van der Waals(vdW)MFTJs,in particular,are promising spintronic devices for the post-Moore era.However,these vdW MFTJs are typically based on multiferroics composed of ferromagnetic and ferroelectric materials or multilayer magnetic materials with sliding ferroelectricity,which increases device fabrication complexity.In this work,we design a vdW MFTJ using bilayer MoPtGe_(2)S_(6),a material with homologous multiferroicity in each monolayer,combined with symmetric PtTe_(2)electrodes.Using frst-principles calculations based on density functional theory and nonequilibrium Green's functions,we theoretically explore the spin-polarized electronic transport properties of this MFTJ.By controlling the ferroelectric and ferromagnetic polarization directions of bilayer MoPtGe_(2)S_(6),the MFTJ can exhibit six distinct non-volatile resistance states,with maximum TMR(137%)and TER(1943%)ratios.Under biaxial strain,TMR and TER can increase to 265%and 4210%,respectively.The TER ratio also increases to 2186%under a 0.1 V bias voltage.Remarkably,the MFTJ exhibits a pronounced spin-fltering and a signifcant negative diferential resistance efect.These fndings not only highlight the potential of monolayer multiferroic MoPtGe_(2)S_(6)for MFTJs but also ofer valuable theoretical insights for future experimental investigations.展开更多
The forming processes of 4,40-dipyridyl-based single-molecule junctions and mechanically induced conductance switching as well as the side-group effects are systematically investigated by applying the ab initio-based ...The forming processes of 4,40-dipyridyl-based single-molecule junctions and mechanically induced conductance switching as well as the side-group effects are systematically investigated by applying the ab initio-based adiabatic geometric optimization method and the one-dimensional transmission combined with three-dimensional correction approximation(OTCTCA)method.The numerical results show that for the 4,40-dipyridyl with a p-conjugated phenyl-phosphoryl or diphenylsilyl side group,the pyridyl vertically anchors on the second atomic layer of the pyramid-shaped Au tip electrode at small inter-electrode distances by laterally pushing the apical Au atom aside,which induces stronger pyridyl-electrode coupling and high-conductance state of the formed junctions.As the inter-electrode distance increases,the pyridyl shifts to the apical Au atom of the tip electrode.This apical Au atom introduces additional scatterings to the tunneling electrons and significantly decreases the conductance of the junctions.Furthermore,for the 4,40-dipyridyl with a phenyl-phosphoryl side group,the probability of manifesting the high-conductance state is decreased due to the oxygen atom reducing the probability of the pyridyl adsorbing on the second layer of Au tip electrode.In contrast,for the 4,40-dipyridyl with a nonconjugated cyclohexyl-phosphoryl side group,the steric hindrance from the bulky cyclohexyl group leads the molecule to preferentially form the O-Au contact,which prevents both the high conductance and mechanically induced conductance switching of the junction.Our results provide a theoretical understanding of the side-group effects on electronic transport properties of single-molecule junctions,offering an alternative explanation for the experimental observations.展开更多
Rational engineering of semiconductor photocatalysts for efficient hydrogen production is of great significance but still challenging,primarily due to the limitations in charge transfer kinetics.Herein,a fascinating p...Rational engineering of semiconductor photocatalysts for efficient hydrogen production is of great significance but still challenging,primarily due to the limitations in charge transfer kinetics.Herein,a fascinating plasmonic tandem heterojunction with the hc-CdS/Mo_(2)C@C heterostructure is aimfully prepared for effectively promoting the charge separation kinetics of the CdS photocatalyst via the synergistic strategy of phase junction,Schottky junction,and photothermal effect.The difference in atomic configuration between cubic-CdS (c-CdS) and hexagonal-CdS (h-CdS) leads to effective charge separation through a typical Ⅱ charge transfer mechanism,and plasmonic Schottky junction further extracts the electrons in the hc-CdS phase junction to realize gradient charge transfer.Besides,the photothermal effect of Mo_(2)C@C helps to expand the light absorption,accelerate charge transfer kinetics,and reduce the hydrogen evolution energy barrier.The carbon layer provides a fast channel for charge transfer and protects the photocatalyst from photocorrosion.As a result,the optimized hc-CMC photocatalyst exhibits a significantly high photocatalytic H_(2)production activity of 28.63 mmol/g/h and apparent quantum efficiency of 61.8%,surpassing most of the reported photocatalysts.This study provides a feasible strategy to enhance the charge transfer kinetics and photocatalytic activity of CdS by constructing plasmonic tandem heterogeneous junctions.展开更多
This article primarily establishes a two-soliton system and employs the Lewis-Riesenfeld invariant inverse control method to achieve shortcuts to adiabaticity(STA)technology.We study an atomic soliton Josephson juncti...This article primarily establishes a two-soliton system and employs the Lewis-Riesenfeld invariant inverse control method to achieve shortcuts to adiabaticity(STA)technology.We study an atomic soliton Josephson junctions(SJJs)device and subsequently compare and analyze it with atomic bosonic Josephson junctions.Moreover,we use higher-order expressions of the auxiliary equations to optimize the results and weaken the detrimental effect of the sloshing amplitude.We find that in the adiabatic shortcut evolution of two systems with time-containing tunnelling rates,the SJJs system is more robust over a rather short time evolution.In comparison with linear ramping,the STA technique is easier to achieve with the precise modulation of the quantum state in the SJJs system.展开更多
Magnetic skyrmions are recognized as potential information carriers for building the next-generation spintronic memory and logic devices.Towards functional device applications,efficient electrical detection of skyrmio...Magnetic skyrmions are recognized as potential information carriers for building the next-generation spintronic memory and logic devices.Towards functional device applications,efficient electrical detection of skyrmions at room temperature is one of the most important prerequisites.展开更多
Quantum interference effect serves as a critical strategy for addressing incorrect energy level alignment between frontier molecular orbitals and electrodes in molecular junctions. Weak-coupling structures offer an ef...Quantum interference effect serves as a critical strategy for addressing incorrect energy level alignment between frontier molecular orbitals and electrodes in molecular junctions. Weak-coupling structures offer an effective approach to suppress phonon thermal conductance. The thermoelectric properties of pure C_(3)N_(4) nanoribbon devices and C_(3)N_(4)-C_(20) molecular junctions are systematically investigated based on density functional theory(DFT) combined with nonequilibrium Green's function(NEGF) formalism. The results show that pure C_(3)N_(4) nanoribbon devices have superior charge transport capabilities and excellent Seebeck coefficients. A remarkable thermoelectric figure of merit(ZT = 0.98)is achieved near 0.09 e V. The pronounced scattering effect induced by embedding a C_(20) molecule in the center of the C_(3)N_(4) nanoribbon significantly suppresses phonon transport. A maximum ZT value of 1.68 is observed at 0.987 e V. The electron mobility of C_(3)N_(4)-C_(20)-par is effectively increased due to quantum interference effect which greatly improves the alignment between the C_(20) molecule's frontier orbital energy level and C_(3)N_(4) electrodes. The C_(3)N_(4)-C_(20)-van der Waals(vd W) molecular junction allows very few phonons to pass through the C_(20) molecule from the left electrode to the right electrode. As a result, the C_(3)N_(4)-C_(20)-vd W junction achieves an excellent ZT value of 3.82 near the Femi level.展开更多
Gastric cancer(GC)is the fifth most prevalent malignancy worldwide and remains a leading cause of cancer-related mortality.Major risk factors for GC include Helicobacter pylori infection,increasing age,high dietary sa...Gastric cancer(GC)is the fifth most prevalent malignancy worldwide and remains a leading cause of cancer-related mortality.Major risk factors for GC include Helicobacter pylori infection,increasing age,high dietary salt intake,and diets deficient in vegetables and fruits.Due to the often subtle and nonspecific early symptoms,coupled with the lack of routine screening programs,a significant proportion of GC cases are diagnosed at advanced stages.The etiology of GC is multifactorial,and diagnosis is confirmed histologically through endoscopic biopsy,followed by staging via computed tomography,positron emission tomography,staging laparoscopy,and endoscopic ultrasound.Treatment strategies typically involve a multidisciplinary approach including chemotherapy,surgical resection,radiotherapy,and emerging immunotherapeutic options.Despite advances in diagnostic and therapeutic modalities,the prognosis of advanced GC remains poor,with high rates of recurrence and metastasis.In recent years,increasing attention has been given to the role of tight junction(TJ)proteins in the pathogenesis and progression of GC.TJ proteins,critical components of epithelial barrier function,have been implicated in various stages of gastric carcinogenesis,from intestinal metaplasia to invasion and metastasis.Infection and inflammation,particularly due to Helicobacter pylori,disrupt TJ integrity,compromising the gastric mucosal barrier and facilitating neoplastic transformation.This review synthesizes current evidence from PubMed,EMBASE,Google Scholar,ScienceDirect,SpringerLink,and other reputable databases to provide a comprehensive overview of the involvement of TJ proteins in GC.By elucidating the molecular interplay between TJ dysregulation and gastric tumorigenesis,this work aims to highlight the potential of TJ proteins as novel diagnostic biomarkers and therapeutic targets in GC management.展开更多
Photocatalysis uses solar energy to convert nitrogen and water directly into ammonia,helping reduce dependence on fossil fuels and offering a way to integrate the nitrogen cycle into a clean energy network.Ohmic junct...Photocatalysis uses solar energy to convert nitrogen and water directly into ammonia,helping reduce dependence on fossil fuels and offering a way to integrate the nitrogen cycle into a clean energy network.Ohmic junctions between metals and semiconductors have demonstrated significant advantages in enhancing stability and reducing carrier recombination,but their application in photocatalytic nitrogen fixation is limited due to the difficulty of work function matching and the complexity of fabrication processes.In this study,density functional theory(DFT) calculations were used to confirm the work function matching between Bi and Bi_(2)Ti_(2)O_(7)(BTO),ensuring the formation of an Ohmic junction.A Bi-Bi_(2)Ti_(2)O_(7)(B-BTO) composite was successfully synthesized via a one-step hydrothermal method,using bismuth nitrate and titanium sulfate as precursors.Compared to pure BTO,the B-BTO heterojunction,driven by dual electron injection from both metal Bi and BTO,significantly increased the ammonia synthesis rate to 686.95 μmol g^(-1)h^(-1),making it the most active nitrogen fixation material among similar pyrochlorebased catalysts to date.The differential charge density calculations,photocurrent(i-t) measurements,and photoluminescence(PL) tests further validate the role of Ohmic contacts in enhancing charge transfer and prolonging carrier lifetimes.This research provides valuable insight into the application of Ohmic junctions in photocatalytic nitrogen fixation and contributes to advancements in this field.展开更多
Objective To study the role of HLB-1 in regulating the organization and function of neuromuscular junctions in nematode Caenorhabditis elegans. Methods To evaluate the functions of HLB-1 in regulating the organization...Objective To study the role of HLB-1 in regulating the organization and function of neuromuscular junctions in nematode Caenorhabditis elegans. Methods To evaluate the functions of HLB-1 in regulating the organization and function of neuromuscular junctions, effects of hlb-1 mutation on the synaptic structures were revealed by uncovering the expression patterns of SNB-1 ：：GFP and UNC-49：GFP, and pharmacologic assays with aldicarb and levamisole were also used to test the synaptic functions. Further rescue and mosaic analysis confirmed HLB-1＇s role in regulating the organization and function of neuromuscular junctions. Results Loss of HLB-1 function did not result in defects in neuronal outgrowth or neuronal loss, but caused obvious defects of SNB-1：：GFP and UNC-49：：GFP puncta localization, suggesting the altered presynaptic and postsynaptic structures. The mutant animals exhibited severe defects in locomotion behaviors and altered responses to an inhibitor of acetylcholinesterase and a cholinergic agonist, indicating the altered presynaptic and postsynaptic functions. Rescue and mosaic analysis experiments suggested that HLB-1 regulated synaptic functions in a cell nonautonomously way. Moreover, HLB- 1 expression was not required for the presynaptic active zone morphology. Genetic evidence further demonstrated that hlb-1 acted in a parallel pathway with syd-2 to regulate the synaptic functions. Conclusion HLB-1 appeared as a new regulator for the organization and function of neuromuscular junctions in C. elegans.展开更多
This paper proposes a novel single electron random number generator （RNG）. The generator consists of multiple tunneling junctions （MTJ） and a hybrid single electron transistor （SET）/MOS output circuit. It is an ...This paper proposes a novel single electron random number generator （RNG）. The generator consists of multiple tunneling junctions （MTJ） and a hybrid single electron transistor （SET）/MOS output circuit. It is an oscillator-based RNG. MTJ is used to implement a high-frequency oscillator, which uses the inherent physical randomness in tunneling events of the MTJ to achieve large frequency drift. The hybrid SET and MOS output circuit is used to amplify and buffer the output signal of the MTJ oscillator. The RNG circuit generates high-quality random digital sequences with a simple structure. The operation speed of this circuit is as high as 1GHz. The circuit also has good driven capability and low power dissipation. This novel random number generator is a promising device for future cryptographic systems and communication applications.展开更多
Epilepsy is a common neurological disorder characterized by periodic and unpredictable seizures.Gap junctions have recently been proposed to be involved in the generation,synchronization and maintenance of seizure eve...Epilepsy is a common neurological disorder characterized by periodic and unpredictable seizures.Gap junctions have recently been proposed to be involved in the generation,synchronization and maintenance of seizure events.The present review mainly summarizes recent reports concerning the contribution of gap junctions to the pathophysiology of epilepsy,together with the regulation of connexin after clinical and experimental seizure activity.The anticonvulsant effects of gap junction blockers both in vitro and in vivo suggest that the gap junction is a candidate target for the development of antiepileptic drugs.It is also of interest that the roles of neuronal and astrocytic gap junctions in epilepsy have been investigated independently,based on evidence from pharmacological manipulations and connexin-knockout mice.Further studies using more specific manipulations of gap junctions in different cell types and in human epileptic tissue are needed to fully uncover the role of gap junctions in epilepsy.展开更多
Inflammatory bowel diseases are characterised by inflammation that compromises the integrity of the epithelial barrier. The intestinal epithelium is not only a static barrier but has evolved complex mechanisms to cont...Inflammatory bowel diseases are characterised by inflammation that compromises the integrity of the epithelial barrier. The intestinal epithelium is not only a static barrier but has evolved complex mechanisms to control and regulate bacterial interactions with the mucosal surface. Apical tight junction proteins are critical in the maintenance of epithelial barrier function and control of paracellular permeability. The characterisation of alterations in tight junction proteins as key players in epithelial barrier function in inflammatory bowel diseases is rapidly enhancing our understanding of critical mechanisms in disease pathogenesis as well as novel therapeutic opportunities. Here we give an overview of recent literature focusing on the role of tight junction proteins, in particular claudins, in inflammatory bowel diseases and inflammatory bowel disease associated colorectal cancer.展开更多
Tight junctions(TJs)are structures between cells where cells appear in the closest possible contact.They are responsible for sealing compartments when epithelial sheets are generated.They regulate the permeability of ...Tight junctions(TJs)are structures between cells where cells appear in the closest possible contact.They are responsible for sealing compartments when epithelial sheets are generated.They regulate the permeability of ions,(macro)molecules and cells via the paracellular pathway.Their structure at the electron microscopic level has been well known since the 1970s;however,only recently has their macromolecular composition been revealed.This review first examines the major macromolecular components of the TJs(occludin,claudins,junctional adhesion molecule and tricellulin)and then the associated macromolecules at the intracellular plaque[zonula occludens(ZO)-1,ZO-2,ZO-3,AF-6,cingulin,7H6].Emphasis is given to their interactions in order to begin to understand the mode of assembly of TJs.The functional significance of TJs is detailed and several mechanisms and factors involved are discussed briefly.Emphasis is given to the role of intestinal TJs and the alterations observed or speculated in diverse disease states.Specifically,intestinal TJs may exert a pathogenetic role in intestinal(inflammatory bowel disease,celiac disease)and extraintestinal diseases (diabetes type 1,food allergies,autoimmune diseases).Additionally,intestinal TJs may be secondarily disrupted during the course of diverse diseases,subsequently allowing the bacterial translocation phenomenon and promoting the systemic inflammatory response,which is often associated with clinical deterioration.The major questions in the field are highlighted.展开更多
Sphingosine-1-phosphate receptor 1 （S1PR1）, a G protein-coupled recep （GPCR）. controls vasct stability by stabilizing vascular endothelial （VE）-cadherin junctional localization and inhibiting vascular endothelia...Sphingosine-1-phosphate receptor 1 （S1PR1）, a G protein-coupled recep （GPCR）. controls vasct stability by stabilizing vascular endothelial （VE）-cadherin junctional localization and inhibiting vascular endothelial growth factor receptor 2（VEGFR2） signaling. However, the molecular mechanisms that link S1PR1 signaling to intracellular effectors remain unknown.In this study,we demonstrate that the heterotrimeric G protein subfamily member Gαs, encoded by GNAS,acts as a relay mediator of S1PR1 signaling to control vascular integrity by stabilizing VE-cadherin at endothelial junctions. The endothelial cell -spectific deletion of Gαs in mice causes early embryonic lethality with massive hemorrhage and a disorganized Vaseuiature.The immunostaining results revealed that Gαs deletion remarkably reduces the junctional localization of VE-cadherin, whereas the mull cell coverage of the vessels is not impaired.In addition, we found-that Gαs depletion blocks the S1PR1-activation induced VE-cadherin stabilization at junctons,supporting that Gαs acts downstream of S1PR1 signaling ThuS, our results demonstrate that Gαs is an essential mediator to relay S1PR1 signaling and maintain vascular integrity.展开更多
Nano-ring-type magnetic tunnel junctions （NR-MTJs） with the layer structure of Ta（5）/Ir22Mn78（10）/ Co75Fe25（2）/Ru（0.75）/CoooFe20B20（3）/Al（0.6）-oxide/Co60Fe20B20（2.5）/Ta（3）/Ru（5） （thickness unit：...Nano-ring-type magnetic tunnel junctions （NR-MTJs） with the layer structure of Ta（5）/Ir22Mn78（10）/ Co75Fe25（2）/Ru（0.75）/CoooFe20B20（3）/Al（0.6）-oxide/Co60Fe20B20（2.5）/Ta（3）/Ru（5） （thickness unit： nm） were nano-fabricated on the Si（100）/SiO2 substrate using magnetron sputtering deposition combined with the optical lithography, electron beam lithography （EBL） and Ar ion-beam etching techniques. The smaller NR-MTJs with the inner- and outer-diameter of around 50 and 100 nm and also their corresponding NR-MTJ arrays were nano-patterned. The tunnelling magnetoresistance （TMR ＆ R） versus driving current （I） loops for a spin-polarized current switching were measured, and the TMR ratio of around 35% at room temperature were observed. The critical values of switching current for the free Co60Fe20B20 layer relative to the reference Co6oFe2oB2o layer between parallel and anti-parallel magnetization states were between 0.50 and 0.75 mA in such NR-MTJs. It is suggested that the applicable MRAM fabrication with the density and capacity higher than 256 Mbit/inch2 even 6 Gbite/inch2 are possible using both I NR-MTJ＋1 transistor structure and current switching mechanism based on based on our fabricated 4×4 MRAM demo devices.展开更多
We develop a fabrication process for the superconducting phase qubits in which Josephson junctions for both the qubit and superconducting quantum interference device（SQUID） detector are prepared by shadow evaporatio...We develop a fabrication process for the superconducting phase qubits in which Josephson junctions for both the qubit and superconducting quantum interference device（SQUID） detector are prepared by shadow evaporation with a suspended bridge. Al junctions with areas as small as 0.05 μm^2 are fabricated for the qubit, in which the number of the decoherencecausing two-level systems（TLS） residing in the tunnel barrier and proportional to the junction area are greatly reduced. The measured energy spectrum shows no avoided crossing arising from coherent TLS in the experimentally reachable flux bias range of the phase qubit, which demonstrates the energy relaxation time T1 and dephasing time Tφ on the order of 100 ns and 50 ns, respectively. We discuss several possible origins of decoherence from incoherent or weakly-coupled coherent TLS and further improvements of the qubit performance.展开更多
Two-dimensional(2D) magnetic crystals have attracted great attention due to their emerging new physical phenomena. They provide ideal platforms to study the fundamental physics of magnetism in low dimensions. In this ...Two-dimensional(2D) magnetic crystals have attracted great attention due to their emerging new physical phenomena. They provide ideal platforms to study the fundamental physics of magnetism in low dimensions. In this research,magnetic tunneling junctions(MTJs) based on XSe2(X = Mn, V) with room-temperature ferromagnetism were studied using first-principles calculations. A large tunneling magnetoresistance(TMR) of 725.07% was obtained in the MTJs based on monolayer MnSe2. Several schemes were proposed to improve the TMR of these devices. Moreover, the results of our non-equilibrium transport calculations showed that the large TMR was maintained in these devices under a finite bias.The transmission spectrum was analyzed according to the orbital components and the electronic structure of the monolayer XSe2(X = Mn, V). The results in this paper demonstrated that the MTJs based on a 2D ferromagnet with room-temperature ferromagnetism exhibited reliable performance. Therefore, such devices show the possibility for potential applications in spintronics.展开更多
We present a scheme for chaotic synchronization in two resistive- capacitive-inductive shunted Josephson junctions （RCLSJJs） by using another chaotic RCLSJJ as a driving system. Numerical simulations show that wheth...We present a scheme for chaotic synchronization in two resistive- capacitive-inductive shunted Josephson junctions （RCLSJJs） by using another chaotic RCLSJJ as a driving system. Numerical simulations show that whether the two RCLSJJs are chaotic or not before being driven, they can realize chaotic synchronization with a suitable driving intensity, under which the maximum condition Lyapunov exponent （MCLE） is negative. On the other hand, if the driving system is in different periodic states or chaotic states, the two driven RCLSJJs can be controlled into the periodic states with different period numbers or chaotic states but still maintain the synchronization.展开更多
基金supported by grants from Collaborative Research Fund(Ref:C4032-21GF)General Research Grant(Ref:14114822)+1 种基金Group Research Scheme(Ref:3110146)Area of Excellence(Ref:Ao E/M-402/20)。
文摘Mitochondrial dysfunction and oxidative stress are widely regarded as primary drivers of aging and are associated with several neurodegenerative diseases.The degeneration of motor neurons during aging is a critical pathological factor contributing to the progression of sarcopenia.However,the morphological and functional changes in mitochondria and their interplay in the degeneration of the neuromuscular junction during aging remain poorly understood.A defined systematic search of the Pub Med,Web of Science and Embase databases(last accessed on October 30,2024)was conducted with search terms including'mitochondria','aging'and'NMJ'.Clinical and preclinical studies of mitochondrial dysfunction and neuromuscular junction degeneration during aging.Twentyseven studies were included in this systematic review.This systematic review provides a summary of morphological,functional and biological changes in neuromuscular junction,mitochondrial morphology,biosynthesis,respiratory chain function,and mitophagy during aging.We focus on the interactions and mechanisms underlying the relationship between mitochondria and neuromuscular junctions during aging.Aging is characterized by significant reductions in mitochondrial fusion/fission cycles,biosynthesis,and mitochondrial quality control,which may lead to neuromuscular junction dysfunction,denervation and poor physical performance.Motor nerve terminals that exhibit redox sensitivity are among the first to exhibit abnormalities,ultimately leading to an early decline in muscle strength through impaired neuromuscular junction transmission function.Parg coactivator 1 alpha is a crucial molecule that regulates mitochondrial biogenesis and modulates various pathways,including the mitochondrial respiratory chain,energy deficiency,oxidative stress,and inflammation.Mitochondrial dysfunction is correlated with neuromuscular junction denervation and acetylcholine receptor fragmentation,resulting in muscle atrophy and a decrease in strength during aging.Physical therapy,pharmacotherapy,and gene therapy can alleviate the structural degeneration and functional deterioration of neuromuscular junction by restoring mitochondrial function.Therefore,mitochondria are considered potential targets for preserving neuromuscular junction morphology and function during aging to treat sarcopenia.
基金supported by the National Key R&D Program of China(Grant No.2022YFB3505301)the National Key R&D Program of Shanxi Province(Grant No.202302050201014)+1 种基金the National Natural Science Foundation of China(Grant No.12304148)the Natural Science Basic Research Program of Shanxi Province(Grant No.202203021222219)。
文摘Multiferroic tunnel junctions(MFTJs),which combine tunneling magnetoresistance(TMR)and electroresistance(TER)efects,have emerged as key candidates for data storage.Two-dimensional van der Waals(vdW)MFTJs,in particular,are promising spintronic devices for the post-Moore era.However,these vdW MFTJs are typically based on multiferroics composed of ferromagnetic and ferroelectric materials or multilayer magnetic materials with sliding ferroelectricity,which increases device fabrication complexity.In this work,we design a vdW MFTJ using bilayer MoPtGe_(2)S_(6),a material with homologous multiferroicity in each monolayer,combined with symmetric PtTe_(2)electrodes.Using frst-principles calculations based on density functional theory and nonequilibrium Green's functions,we theoretically explore the spin-polarized electronic transport properties of this MFTJ.By controlling the ferroelectric and ferromagnetic polarization directions of bilayer MoPtGe_(2)S_(6),the MFTJ can exhibit six distinct non-volatile resistance states,with maximum TMR(137%)and TER(1943%)ratios.Under biaxial strain,TMR and TER can increase to 265%and 4210%,respectively.The TER ratio also increases to 2186%under a 0.1 V bias voltage.Remarkably,the MFTJ exhibits a pronounced spin-fltering and a signifcant negative diferential resistance efect.These fndings not only highlight the potential of monolayer multiferroic MoPtGe_(2)S_(6)for MFTJs but also ofer valuable theoretical insights for future experimental investigations.
基金supported by the National Natural Science Foundation of China(Grant Nos.12474286,22173052,and 12204281).
文摘The forming processes of 4,40-dipyridyl-based single-molecule junctions and mechanically induced conductance switching as well as the side-group effects are systematically investigated by applying the ab initio-based adiabatic geometric optimization method and the one-dimensional transmission combined with three-dimensional correction approximation(OTCTCA)method.The numerical results show that for the 4,40-dipyridyl with a p-conjugated phenyl-phosphoryl or diphenylsilyl side group,the pyridyl vertically anchors on the second atomic layer of the pyramid-shaped Au tip electrode at small inter-electrode distances by laterally pushing the apical Au atom aside,which induces stronger pyridyl-electrode coupling and high-conductance state of the formed junctions.As the inter-electrode distance increases,the pyridyl shifts to the apical Au atom of the tip electrode.This apical Au atom introduces additional scatterings to the tunneling electrons and significantly decreases the conductance of the junctions.Furthermore,for the 4,40-dipyridyl with a phenyl-phosphoryl side group,the probability of manifesting the high-conductance state is decreased due to the oxygen atom reducing the probability of the pyridyl adsorbing on the second layer of Au tip electrode.In contrast,for the 4,40-dipyridyl with a nonconjugated cyclohexyl-phosphoryl side group,the steric hindrance from the bulky cyclohexyl group leads the molecule to preferentially form the O-Au contact,which prevents both the high conductance and mechanically induced conductance switching of the junction.Our results provide a theoretical understanding of the side-group effects on electronic transport properties of single-molecule junctions,offering an alternative explanation for the experimental observations.
基金National Natural Science Foundation of China (Nos. 22371165, 22209098 and 21971143)111 Project (D20015)Opening Found of Hubei Three Gorges Laboratory (SC232001, SK213002)。
文摘Rational engineering of semiconductor photocatalysts for efficient hydrogen production is of great significance but still challenging,primarily due to the limitations in charge transfer kinetics.Herein,a fascinating plasmonic tandem heterojunction with the hc-CdS/Mo_(2)C@C heterostructure is aimfully prepared for effectively promoting the charge separation kinetics of the CdS photocatalyst via the synergistic strategy of phase junction,Schottky junction,and photothermal effect.The difference in atomic configuration between cubic-CdS (c-CdS) and hexagonal-CdS (h-CdS) leads to effective charge separation through a typical Ⅱ charge transfer mechanism,and plasmonic Schottky junction further extracts the electrons in the hc-CdS phase junction to realize gradient charge transfer.Besides,the photothermal effect of Mo_(2)C@C helps to expand the light absorption,accelerate charge transfer kinetics,and reduce the hydrogen evolution energy barrier.The carbon layer provides a fast channel for charge transfer and protects the photocatalyst from photocorrosion.As a result,the optimized hc-CMC photocatalyst exhibits a significantly high photocatalytic H_(2)production activity of 28.63 mmol/g/h and apparent quantum efficiency of 61.8%,surpassing most of the reported photocatalysts.This study provides a feasible strategy to enhance the charge transfer kinetics and photocatalytic activity of CdS by constructing plasmonic tandem heterogeneous junctions.
基金supported by the National Natural Science Foundation of China(Grant nos.12075145 and 12211540002)the Science and Technology Commission of Shanghai Municipal(Grant no.2019SHZDZX01-ZX04)。
文摘This article primarily establishes a two-soliton system and employs the Lewis-Riesenfeld invariant inverse control method to achieve shortcuts to adiabaticity(STA)technology.We study an atomic soliton Josephson junctions(SJJs)device and subsequently compare and analyze it with atomic bosonic Josephson junctions.Moreover,we use higher-order expressions of the auxiliary equations to optimize the results and weaken the detrimental effect of the sloshing amplitude.We find that in the adiabatic shortcut evolution of two systems with time-containing tunnelling rates,the SJJs system is more robust over a rather short time evolution.In comparison with linear ramping,the STA technique is easier to achieve with the precise modulation of the quantum state in the SJJs system.
基金supported by the National Key R&D Program of China(Grant No.2022YFA1405100)the NSFC distinguished Young Scholar program(Grant No.12225409)+6 种基金the Basic Science Center Project of National Natural Science Foundation of China(NSFC)(Grant No.52388201)the NSFC general program(Grant Nos.52271181,51831005,and 12421004)the Innovation Program for Quantum Science and Technology(Grant No.2023ZD0300500)Beijing Natural Science Foundation(Grant No.Z240006)supported by the KAUST Office of Sponsored Research(OSR)under Award Nos.ORA-CRG102021-4665 and ORA-CRG11-2022-5031supported by the National Key Research and Development Program of China(No.2024YFA1408503)Sichuan Province Science and Technology Support Program(No.2025YFHZ0147)。
文摘Magnetic skyrmions are recognized as potential information carriers for building the next-generation spintronic memory and logic devices.Towards functional device applications,efficient electrical detection of skyrmions at room temperature is one of the most important prerequisites.
基金Project supported by the National Natural Science Foundation of China (Grant No. 12164046)。
文摘Quantum interference effect serves as a critical strategy for addressing incorrect energy level alignment between frontier molecular orbitals and electrodes in molecular junctions. Weak-coupling structures offer an effective approach to suppress phonon thermal conductance. The thermoelectric properties of pure C_(3)N_(4) nanoribbon devices and C_(3)N_(4)-C_(20) molecular junctions are systematically investigated based on density functional theory(DFT) combined with nonequilibrium Green's function(NEGF) formalism. The results show that pure C_(3)N_(4) nanoribbon devices have superior charge transport capabilities and excellent Seebeck coefficients. A remarkable thermoelectric figure of merit(ZT = 0.98)is achieved near 0.09 e V. The pronounced scattering effect induced by embedding a C_(20) molecule in the center of the C_(3)N_(4) nanoribbon significantly suppresses phonon transport. A maximum ZT value of 1.68 is observed at 0.987 e V. The electron mobility of C_(3)N_(4)-C_(20)-par is effectively increased due to quantum interference effect which greatly improves the alignment between the C_(20) molecule's frontier orbital energy level and C_(3)N_(4) electrodes. The C_(3)N_(4)-C_(20)-van der Waals(vd W) molecular junction allows very few phonons to pass through the C_(20) molecule from the left electrode to the right electrode. As a result, the C_(3)N_(4)-C_(20)-vd W junction achieves an excellent ZT value of 3.82 near the Femi level.
文摘Gastric cancer(GC)is the fifth most prevalent malignancy worldwide and remains a leading cause of cancer-related mortality.Major risk factors for GC include Helicobacter pylori infection,increasing age,high dietary salt intake,and diets deficient in vegetables and fruits.Due to the often subtle and nonspecific early symptoms,coupled with the lack of routine screening programs,a significant proportion of GC cases are diagnosed at advanced stages.The etiology of GC is multifactorial,and diagnosis is confirmed histologically through endoscopic biopsy,followed by staging via computed tomography,positron emission tomography,staging laparoscopy,and endoscopic ultrasound.Treatment strategies typically involve a multidisciplinary approach including chemotherapy,surgical resection,radiotherapy,and emerging immunotherapeutic options.Despite advances in diagnostic and therapeutic modalities,the prognosis of advanced GC remains poor,with high rates of recurrence and metastasis.In recent years,increasing attention has been given to the role of tight junction(TJ)proteins in the pathogenesis and progression of GC.TJ proteins,critical components of epithelial barrier function,have been implicated in various stages of gastric carcinogenesis,from intestinal metaplasia to invasion and metastasis.Infection and inflammation,particularly due to Helicobacter pylori,disrupt TJ integrity,compromising the gastric mucosal barrier and facilitating neoplastic transformation.This review synthesizes current evidence from PubMed,EMBASE,Google Scholar,ScienceDirect,SpringerLink,and other reputable databases to provide a comprehensive overview of the involvement of TJ proteins in GC.By elucidating the molecular interplay between TJ dysregulation and gastric tumorigenesis,this work aims to highlight the potential of TJ proteins as novel diagnostic biomarkers and therapeutic targets in GC management.
基金supported by the Natural Science Foundation of China (NSFC,No.52372212)。
文摘Photocatalysis uses solar energy to convert nitrogen and water directly into ammonia,helping reduce dependence on fossil fuels and offering a way to integrate the nitrogen cycle into a clean energy network.Ohmic junctions between metals and semiconductors have demonstrated significant advantages in enhancing stability and reducing carrier recombination,but their application in photocatalytic nitrogen fixation is limited due to the difficulty of work function matching and the complexity of fabrication processes.In this study,density functional theory(DFT) calculations were used to confirm the work function matching between Bi and Bi_(2)Ti_(2)O_(7)(BTO),ensuring the formation of an Ohmic junction.A Bi-Bi_(2)Ti_(2)O_(7)(B-BTO) composite was successfully synthesized via a one-step hydrothermal method,using bismuth nitrate and titanium sulfate as precursors.Compared to pure BTO,the B-BTO heterojunction,driven by dual electron injection from both metal Bi and BTO,significantly increased the ammonia synthesis rate to 686.95 μmol g^(-1)h^(-1),making it the most active nitrogen fixation material among similar pyrochlorebased catalysts to date.The differential charge density calculations,photocurrent(i-t) measurements,and photoluminescence(PL) tests further validate the role of Ohmic contacts in enhancing charge transfer and prolonging carrier lifetimes.This research provides valuable insight into the application of Ohmic junctions in photocatalytic nitrogen fixation and contributes to advancements in this field.
基金the National Natural Science Foundation of China (No. 30771113, 30870810)the Program for New Century Excellent Talents in University, Ministry of Education, China
文摘Objective To study the role of HLB-1 in regulating the organization and function of neuromuscular junctions in nematode Caenorhabditis elegans. Methods To evaluate the functions of HLB-1 in regulating the organization and function of neuromuscular junctions, effects of hlb-1 mutation on the synaptic structures were revealed by uncovering the expression patterns of SNB-1 ：：GFP and UNC-49：GFP, and pharmacologic assays with aldicarb and levamisole were also used to test the synaptic functions. Further rescue and mosaic analysis confirmed HLB-1＇s role in regulating the organization and function of neuromuscular junctions. Results Loss of HLB-1 function did not result in defects in neuronal outgrowth or neuronal loss, but caused obvious defects of SNB-1：：GFP and UNC-49：：GFP puncta localization, suggesting the altered presynaptic and postsynaptic structures. The mutant animals exhibited severe defects in locomotion behaviors and altered responses to an inhibitor of acetylcholinesterase and a cholinergic agonist, indicating the altered presynaptic and postsynaptic functions. Rescue and mosaic analysis experiments suggested that HLB-1 regulated synaptic functions in a cell nonautonomously way. Moreover, HLB- 1 expression was not required for the presynaptic active zone morphology. Genetic evidence further demonstrated that hlb-1 acted in a parallel pathway with syd-2 to regulate the synaptic functions. Conclusion HLB-1 appeared as a new regulator for the organization and function of neuromuscular junctions in C. elegans.
文摘This paper proposes a novel single electron random number generator （RNG）. The generator consists of multiple tunneling junctions （MTJ） and a hybrid single electron transistor （SET）/MOS output circuit. It is an oscillator-based RNG. MTJ is used to implement a high-frequency oscillator, which uses the inherent physical randomness in tunneling events of the MTJ to achieve large frequency drift. The hybrid SET and MOS output circuit is used to amplify and buffer the output signal of the MTJ oscillator. The RNG circuit generates high-quality random digital sequences with a simple structure. The operation speed of this circuit is as high as 1GHz. The circuit also has good driven capability and low power dissipation. This novel random number generator is a promising device for future cryptographic systems and communication applications.
基金supported by the National Basic Research Development Program (973 Program) of China (2011CB504403)the National Natural Science Foundation of China (81030061,30725047,and 30801392)
文摘Epilepsy is a common neurological disorder characterized by periodic and unpredictable seizures.Gap junctions have recently been proposed to be involved in the generation,synchronization and maintenance of seizure events.The present review mainly summarizes recent reports concerning the contribution of gap junctions to the pathophysiology of epilepsy,together with the regulation of connexin after clinical and experimental seizure activity.The anticonvulsant effects of gap junction blockers both in vitro and in vivo suggest that the gap junction is a candidate target for the development of antiepileptic drugs.It is also of interest that the roles of neuronal and astrocytic gap junctions in epilepsy have been investigated independently,based on evidence from pharmacological manipulations and connexin-knockout mice.Further studies using more specific manipulations of gap junctions in different cell types and in human epileptic tissue are needed to fully uncover the role of gap junctions in epilepsy.
基金Supported by The Association for International Cancer Research(AICRto Dr.Al-Hassi HO)+6 种基金ScotlandFunded by the AICRgrant No.120234a BBSRC Strategic Research Grant(to English N and Knight SCWMNIP33458)the St Mark’s Hospital FoundationUnited Kingdom
文摘Inflammatory bowel diseases are characterised by inflammation that compromises the integrity of the epithelial barrier. The intestinal epithelium is not only a static barrier but has evolved complex mechanisms to control and regulate bacterial interactions with the mucosal surface. Apical tight junction proteins are critical in the maintenance of epithelial barrier function and control of paracellular permeability. The characterisation of alterations in tight junction proteins as key players in epithelial barrier function in inflammatory bowel diseases is rapidly enhancing our understanding of critical mechanisms in disease pathogenesis as well as novel therapeutic opportunities. Here we give an overview of recent literature focusing on the role of tight junction proteins, in particular claudins, in inflammatory bowel diseases and inflammatory bowel disease associated colorectal cancer.
文摘Tight junctions(TJs)are structures between cells where cells appear in the closest possible contact.They are responsible for sealing compartments when epithelial sheets are generated.They regulate the permeability of ions,(macro)molecules and cells via the paracellular pathway.Their structure at the electron microscopic level has been well known since the 1970s;however,only recently has their macromolecular composition been revealed.This review first examines the major macromolecular components of the TJs(occludin,claudins,junctional adhesion molecule and tricellulin)and then the associated macromolecules at the intracellular plaque[zonula occludens(ZO)-1,ZO-2,ZO-3,AF-6,cingulin,7H6].Emphasis is given to their interactions in order to begin to understand the mode of assembly of TJs.The functional significance of TJs is detailed and several mechanisms and factors involved are discussed briefly.Emphasis is given to the role of intestinal TJs and the alterations observed or speculated in diverse disease states.Specifically,intestinal TJs may exert a pathogenetic role in intestinal(inflammatory bowel disease,celiac disease)and extraintestinal diseases (diabetes type 1,food allergies,autoimmune diseases).Additionally,intestinal TJs may be secondarily disrupted during the course of diverse diseases,subsequently allowing the bacterial translocation phenomenon and promoting the systemic inflammatory response,which is often associated with clinical deterioration.The major questions in the field are highlighted.
基金partially supported by the grants from the Ministry of Science & Technology-China (Nos.2014CB964600 and 2012CB966800)the National Science Foundation of China (Nos. 31301125 and 31071283)+2 种基金Shenzhen Peacock Plan (No. KQCX20130628112914292)Shenzhen Key Laboratory for Molecular Biology of Neural Development (No. ZDSY20120617112838879)SIAT Innovation Program for Excellent Young Researchers (No. 201404)
文摘Sphingosine-1-phosphate receptor 1 （S1PR1）, a G protein-coupled recep （GPCR）. controls vasct stability by stabilizing vascular endothelial （VE）-cadherin junctional localization and inhibiting vascular endothelial growth factor receptor 2（VEGFR2） signaling. However, the molecular mechanisms that link S1PR1 signaling to intracellular effectors remain unknown.In this study,we demonstrate that the heterotrimeric G protein subfamily member Gαs, encoded by GNAS,acts as a relay mediator of S1PR1 signaling to control vascular integrity by stabilizing VE-cadherin at endothelial junctions. The endothelial cell -spectific deletion of Gαs in mice causes early embryonic lethality with massive hemorrhage and a disorganized Vaseuiature.The immunostaining results revealed that Gαs deletion remarkably reduces the junctional localization of VE-cadherin, whereas the mull cell coverage of the vessels is not impaired.In addition, we found-that Gαs depletion blocks the S1PR1-activation induced VE-cadherin stabilization at junctons,supporting that Gαs acts downstream of S1PR1 signaling ThuS, our results demonstrate that Gαs is an essential mediator to relay S1PR1 signaling and maintain vascular integrity.
基金the State Key Project of Fundamental Research of Ministry of Science and Technology （No. 2006CB932200） the National Natural Science Foundation of China （NSFC, No. 10574156）+2 种基金 the Knowledge Innovation Program of Chinese Aca.demy of Sciencesthe protial support of 0utstanding Young Researcher Foundation （Nos. 50325104 and 50528101） K.C.Wong Education Foundation, Hong Kong.
文摘Nano-ring-type magnetic tunnel junctions （NR-MTJs） with the layer structure of Ta（5）/Ir22Mn78（10）/ Co75Fe25（2）/Ru（0.75）/CoooFe20B20（3）/Al（0.6）-oxide/Co60Fe20B20（2.5）/Ta（3）/Ru（5） （thickness unit： nm） were nano-fabricated on the Si（100）/SiO2 substrate using magnetron sputtering deposition combined with the optical lithography, electron beam lithography （EBL） and Ar ion-beam etching techniques. The smaller NR-MTJs with the inner- and outer-diameter of around 50 and 100 nm and also their corresponding NR-MTJ arrays were nano-patterned. The tunnelling magnetoresistance （TMR ＆ R） versus driving current （I） loops for a spin-polarized current switching were measured, and the TMR ratio of around 35% at room temperature were observed. The critical values of switching current for the free Co60Fe20B20 layer relative to the reference Co6oFe2oB2o layer between parallel and anti-parallel magnetization states were between 0.50 and 0.75 mA in such NR-MTJs. It is suggested that the applicable MRAM fabrication with the density and capacity higher than 256 Mbit/inch2 even 6 Gbite/inch2 are possible using both I NR-MTJ＋1 transistor structure and current switching mechanism based on based on our fabricated 4×4 MRAM demo devices.
基金supported by the National Basic Research Program of China(Grant Nos.2014CB921202,2015CB921104,and 2016YFA0300601)the National Natural Science Foundation of China(Grant Nos.91321208 and 11674380)
文摘We develop a fabrication process for the superconducting phase qubits in which Josephson junctions for both the qubit and superconducting quantum interference device（SQUID） detector are prepared by shadow evaporation with a suspended bridge. Al junctions with areas as small as 0.05 μm^2 are fabricated for the qubit, in which the number of the decoherencecausing two-level systems（TLS） residing in the tunnel barrier and proportional to the junction area are greatly reduced. The measured energy spectrum shows no avoided crossing arising from coherent TLS in the experimentally reachable flux bias range of the phase qubit, which demonstrates the energy relaxation time T1 and dephasing time Tφ on the order of 100 ns and 50 ns, respectively. We discuss several possible origins of decoherence from incoherent or weakly-coupled coherent TLS and further improvements of the qubit performance.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61571415 and 61622406)the National Key Research and Development Program of China(Grant No.2017YFA0207500)+1 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB30000000)Beijing Academy of Quantum Information Sciences,China(Grant No.Y18G04)
文摘Two-dimensional(2D) magnetic crystals have attracted great attention due to their emerging new physical phenomena. They provide ideal platforms to study the fundamental physics of magnetism in low dimensions. In this research,magnetic tunneling junctions(MTJs) based on XSe2(X = Mn, V) with room-temperature ferromagnetism were studied using first-principles calculations. A large tunneling magnetoresistance(TMR) of 725.07% was obtained in the MTJs based on monolayer MnSe2. Several schemes were proposed to improve the TMR of these devices. Moreover, the results of our non-equilibrium transport calculations showed that the large TMR was maintained in these devices under a finite bias.The transmission spectrum was analyzed according to the orbital components and the electronic structure of the monolayer XSe2(X = Mn, V). The results in this paper demonstrated that the MTJs based on a 2D ferromagnet with room-temperature ferromagnetism exhibited reliable performance. Therefore, such devices show the possibility for potential applications in spintronics.
文摘We present a scheme for chaotic synchronization in two resistive- capacitive-inductive shunted Josephson junctions （RCLSJJs） by using another chaotic RCLSJJ as a driving system. Numerical simulations show that whether the two RCLSJJs are chaotic or not before being driven, they can realize chaotic synchronization with a suitable driving intensity, under which the maximum condition Lyapunov exponent （MCLE） is negative. On the other hand, if the driving system is in different periodic states or chaotic states, the two driven RCLSJJs can be controlled into the periodic states with different period numbers or chaotic states but still maintain the synchronization.
