Metal sulfides are a class of promising anode materials for sodium-ion batteries(SIBs)owing to their high theoretical specific capacity.Nevertheless,the reactant products(polysulfides)could dissolve into electrolyte,s...Metal sulfides are a class of promising anode materials for sodium-ion batteries(SIBs)owing to their high theoretical specific capacity.Nevertheless,the reactant products(polysulfides)could dissolve into electrolyte,shuttle across separator,and react with sodium anode,leading to severe capacity loss and safety concerns.Herein,for the first time,gallium(Ga)-based liquid metal(LM)alloy is incorporated with MoS_(2)nanosheets to work as an anode in SIBs.The electron-rich,ultrahigh electrical conductivity,and self-healing properties of LM endow the heterostructured MoS_(2)-LM with highly improved conductivity and electrode integrity.Moreover,LM is demonstrated to have excellent capability for the adsorption of polysulfides(e.g.,Na_(2)S,Na_(2)S_(6),and S_(8))and subsequent catalytic conversion of Na_(2)S.Consequently,the MoS_(2)-LM electrode exhibits superior ion diffusion kinetics and long cycling performance in SIBs and even in lithium/potassium-ion battery(LIB/PIB)systems,far better than those electrodes with conventional binders(polyvinylidene difluoride(PVDF)and sodium carboxymethyl cellulose(CMC)).This work provides a unique material design concept based on Ga-based liquid metal alloy for metal sulfide anodes in rechargeable battery systems and beyond.展开更多
Nuclear accumulation of active Smad complexes is crucial for transduction of transforming growth factor β （TGF-β）- superfamily signals from transmembrane receptors into the nucleus. It is now clear that the nucleo...Nuclear accumulation of active Smad complexes is crucial for transduction of transforming growth factor β （TGF-β）- superfamily signals from transmembrane receptors into the nucleus. It is now clear that the nucleocytoplasmic distributions of Smads, in both the absence and the presence of a TGF-β-superfamily signal, are not static, but instead the Smads are continuously shuttling between the nucleus and the cytoplasm in both conditions. This article presents the evidence for continuous nucleocytoplasmic shuttling of Smads. It then reviews different mechanisms that have been proposed to mediate Smad nuclear import and export, and discusses how the Smad steady-state distributions in the absence and the presence of a TGF-β-superfamily signal are established. Finally, the biological relevance of continuous nucleocytoplasmic shuttling for signaling by TGF-β superfamily members is discussed.展开更多
Stereoblock polypropyienes bearing isotactic,atactic,and syndictactic polypropylene segments were successfully prepared by dry methylaluminoxane activated binary catalysts system,Ph2CFluCpZrCl2 and {Me2Si(2,5-Me2-3-(2...Stereoblock polypropyienes bearing isotactic,atactic,and syndictactic polypropylene segments were successfully prepared by dry methylaluminoxane activated binary catalysts system,Ph2CFluCpZrCl2 and {Me2Si(2,5-Me2-3-(2-MePh)-cyclopento[2,3-b]thiophen-6-yl)2}ZCl2,in the presence of iBu3Al as a chain shutting agent.by studying the catalyst activity,chain transfer efficiency,and reversility of chain transfer reaction of each catalyst system,as well as the molecular weight and polydispersity of the resulting polymers,the allyl exchange reactions between the zirconium catalyst and different main-group metal alky were estimated,respectvely.Based on the optimized react condition,the chain shuttling polymerization was conducted by binary catalyst system in the presence of iBu3Al under both atmospheric and high pressure.Resultant polymers were identified as stereoblock polypropylenes according to microstructure and physical properties analyses by 13C{1H}-NMR,DsC,and GPC.展开更多
Sodium-oxygen batteries(Na-O_(2))have attracted extensive attention as promising energy storage systems due to their high energy density and low cost.Redox mediators are often employed to improve Na-O_(2) battery perf...Sodium-oxygen batteries(Na-O_(2))have attracted extensive attention as promising energy storage systems due to their high energy density and low cost.Redox mediators are often employed to improve Na-O_(2) battery performance,however,their effect on the formation mechanism of the oxygen reduction product(NaO_(2))is still unclear.Here,we have investigated the formation mechanism of NaO_(2) during the discharge process in the presence of a redox mediator with the help of atomic/nano-scale in-situ characterization tools used in concert(e.g.atomic force microscope,electrochemical quartz crystal microbalance(EQCM)and laser nano-particle analyzer).As a result,real-time observations on different time scales show that by shuttling electrons to the electrolyte,the redox mediator enables formation of NaO_(2) in the solution-phase instead of within a finite region near the electrode surface.These findings provide new fundamental insights on the understanding of Na-O_(2) batteries and new consequently perspectives on designing high performance metal-O_(2) batteries and other related functions.展开更多
A bistable[2]rotaxane with a conformation-adaptive macrocycle bearing a 9,14-diphenyl-9,14-dihydrodibenzo[a,c]phenazine(DPAC)unit was synthesized,which could be utilized to optical probe the molecular shuttling motion...A bistable[2]rotaxane with a conformation-adaptive macrocycle bearing a 9,14-diphenyl-9,14-dihydrodibenzo[a,c]phenazine(DPAC)unit was synthesized,which could be utilized to optical probe the molecular shuttling motion of the functionalized rotaxane system.The UV-vis,^(1) H NMR and PL spectroscopic data clearly demonstrated that the DPAC ring was interlocked onto the thread and the fluorescence intensity of the DPAC unit in the macrocycle was effectively regulated by the location change of the macrocycle along the thread under acid/base stimulation,which was attributed to the modulation of the intramolecular photo-induced electron transfer between the DPAC unit and the methyltriazole(MTA)unit.This bistable rotaxane system containing a conformation-adaptive fluorophore unit in the macrocycle moiety opens an alternative way to design functional bistable mechanically interlocked molecules.展开更多
Targeting early steps in amyloid-beta production：Alzheimer’s disease（AD）has a long history as the＂amyloid deposit＂disorder.Many disorders are now known to be caused by proteinβ-sheet misfolding and aggregation...Targeting early steps in amyloid-beta production：Alzheimer’s disease（AD）has a long history as the＂amyloid deposit＂disorder.Many disorders are now known to be caused by proteinβ-sheet misfolding and aggregation（e.g.,Parkinson’s disease：α-synuclein;Huntington’s disease：Huntingtin;展开更多
P68 RNA helicase is a prototypical DEAD box RNA helicase. The protein plays a very important role in early organ development and maturation. Consistent with the function of the protein in transcriptional regulation an...P68 RNA helicase is a prototypical DEAD box RNA helicase. The protein plays a very important role in early organ development and maturation. Consistent with the function of the protein in transcriptional regulation and pre-mRNA splicing, p68 was found to predominately localize in the cell nucleus. However, recent experiments demon- strate a transient cytoplasmic localization of the protein. We report here that p68 shuttles between the nucleus and the cytoplasm. The nucleocytoplasmic shuttling of p68 is mediated by two nuclear localization signal and two nuclear exporting signal sequence elements. Our experiments reveal that p68 shuttles via a classical RanGTPase-dependent pathway.展开更多
Although lithium iodide(LiI)as a redox mediator(RM)can decrease the overpotential in Li-O_(2)batteries,the stability of the Li anode is still one critical issue due to the redox shuttling.Here,we firstly present a nov...Although lithium iodide(LiI)as a redox mediator(RM)can decrease the overpotential in Li-O_(2)batteries,the stability of the Li anode is still one critical issue due to the redox shuttling.Here,we firstly present a novel approach for generating Ag and LiTFSI enriched Li anode(designated as ALE@Li anode)via a spontaneous substitution between pure Li and bis(trifluoromethanesulfonyl)imide silver,in a LiI-participated Li-O_(2)cell.It can induce the generation of a lithiophilic solid electrolyte interphase(SEI)enriched with Ag,F,and N species(e.g.,Ag_(2)O,Li-Ag alloy,LiF,and Li_(3)N)during cell operation,which contributes to promoting the electrochemical performance through the shuttling inhibition.Compared to a cell with a bare Li anode,the one with as-prepared ALE@Li anode shows an enhanced cyclability,a considerable rate capability,and a good reversibility.In addition,a synchrotron X-ray computed tomography technique is employed to investigate the inhibition mechanism for shuttling effect by monitoring the morphological evolution on the cell interfaces.Therefore,this work highlights the deliberate design in the modified Li anode in an easy-to-operate and cost-effective way as well as providing guidance for the construction of artificial SEI layers to suppress the redox shuttling of RMs in Li-O_(2)batteries.展开更多
Lithium-sulfur(Li-S)batteries,known for their high energy density,are attracting extensive research interest as a promising next-generation energy storage technology.However,their widespread use has been hampered by c...Lithium-sulfur(Li-S)batteries,known for their high energy density,are attracting extensive research interest as a promising next-generation energy storage technology.However,their widespread use has been hampered by certain issues,including the dissolution and migration of polysulfides,along with sluggish redox kinetics.Metal sulfides present a promising solution to these obstacles regarding their high electrical conductivity,strong chemical adsorption with polysulfides,and remarkable electrocatalytic capabilities for polysulfide conversion.In this review,the recent progress on the utilization of metal sulfide for suppressing polysulfide shuttling in Li-S batteries is systematically summarized,with a special focus on sulfur hosts and functional separators.The critical roles of metal sulfides in realizing high-performing Li-S batteries have been comprehensively discussed by correlating the materials’structure and electrochemical performances.Moreover,the remaining issues/challenges and future perspectives are highlighted.By offering a detailed understanding of the crucial roles of metal sulfides,this review dedicates to contributing valuable knowledge for the pursuit of high-efficiency Li-S batteries based on metal sulfides.展开更多
Metal organic frameworks(MOFs)are crystalline materials with three-dimensional porous network structure.They are obtained by self-assembly of coordinate bond with metal ions as the nodes and organic ligands as the con...Metal organic frameworks(MOFs)are crystalline materials with three-dimensional porous network structure.They are obtained by self-assembly of coordinate bond with metal ions as the nodes and organic ligands as the connecting chains.MOFs have attracted extensive attention from researchers over the years due to their clear pore and rich topological structure.As the typical powder materials,a specific separator manufacturing process must be possessed when incorporating MOFs into lithium sulfur batteries separator.This mini review summarized the manufacturing process of MOFs separator for LSBs in recent years,and summed up the effects and mechanisms of separators prepared by various separator-forming processes on the performance of LSBs,the potential for industrialization of different separator manufacturing processes is also mentioned briefly.展开更多
Many geminivirus C4 proteins induce severe developmental abnormalities in plants.We previously demon- strated that Tomato leaf curl Yunnan virus (TLCYnV)C4 induces plant developmental abnormalities at least partically...Many geminivirus C4 proteins induce severe developmental abnormalities in plants.We previously demon- strated that Tomato leaf curl Yunnan virus (TLCYnV)C4 induces plant developmental abnormalities at least partically by decreasing the accumulation of NbSKη,an ortholog of Arabidopsis BIN2 kinase involved in the brassinosteroid signaling pathway,in the nucleus through directing it to the plasma membrane.However, the molecular mechanism by which the membrane-associated C4 modifies the localization of NbSKη in the host cell remains unclear.Here,we show that TLCYnV C4 is a nucleocytoplasmic shuttle protein,and that C4 shuttling is accompanied by nuclear export of NbSKTI.TLCYnV C4 is phosphorylated by NbSKη in the nucleus,which promotes myristoylation of the viral protein.Myristoylation of phosphorylated C4 favors its interaction with exportin-α(XPO I);which in turn facilitates nuclear export of the C4/NbSKTI complex. Supporting this model,chemical inhibition of N-myristoyltransferases or exportin-α enhanced nuclear retention of C4,and mutations of the putative phosphorylation or myristoylation sites in C4 resulted in increased nuclear retention ofrC4 and thus decreased severity of C4-induced developmental abnormalities. The impact of C4 on development is also lessened when a nuclear localization signal or a nuclear export signal is added to its C-terminus,restricting it to a specific cellular niche and therefore impairing nucleocytoplasmic shuttling.Taken together,our results suggest that nucleocytoplasmic shuttling of TLCYnV C4,enabled by phosphorylation by NbSKη,myristoylation,and interaction with exportin-α is critical for its function as a pathogenicity factor.展开更多
Farnesoid X receptor(FXR)is widely accepted as a promising target for various liver diseases;however,panels of ligands in drug development show limited clinical benefits,without a clear mechanism.Here,we reveal that a...Farnesoid X receptor(FXR)is widely accepted as a promising target for various liver diseases;however,panels of ligands in drug development show limited clinical benefits,without a clear mechanism.Here,we reveal that acetylation initiates and orchestrates FXR nucleocytoplasmic shuttling and then enhances degradation by the cytosolic E3 ligase CHIP under conditions of liver injury,which represents the major culprit that limits the clinical benefits of FXR agonists against liver diseases.Upon inflammatory and apoptotic stimulation,enhanced FXR acetylation at K217,closed to the nuclear location signal,blocks its recognition by importin KPNA3,thereby preventing its nuclear import.Concomitantly,reduced phosphorylation at T442 within the nuclear export signals promotes its recognition by exportin CRM1,and thereby facilitating FXR export to the cytosol.Acetylation governs nucleocytoplasmic shuttling of FXR,resulting in enhanced cytosolic retention of FXR that is amenable to degradation by CHIP.SIRT1 activators reduce FXR acetylation and prevent its cytosolic degradation.More importantly,SIRT1 activators synergize with FXR agonists in combating acute and chronic liver injuries.In conclusion,these findings innovate a promising strategy to develop therapeutics against liver diseases by combining SIRT1 activators and FXR agonists.展开更多
Metal-iodine batteries have attracted widespread attention due to their long cycle life,high energy density,remarkable charging capability and low self-discharge rate.Nevertheless,this development is hampered by the c...Metal-iodine batteries have attracted widespread attention due to their long cycle life,high energy density,remarkable charging capability and low self-discharge rate.Nevertheless,this development is hampered by the challenges of the iodine cathode and metal anode,including the hydrogen evolution reaction(HER),sluggish kinetics,shuttle effect of polyiodine ion at the cathode and dendrite formation,corrosion and passivation at the anode.This review summarizes recent developments in metaliodine batteries,including zinc-iodine batteries,lithiumiodine batteries,sodium-iodine batteries,etc.The challenges in the cathode,anode,electrolyte and separator of metal-iodine batteries are discussed,along with the corresponding design and synthesis strategies and specific methods to improve the electrochemical performance.Selecting appropriate cathode hosts,constructing surface protective layers,adding anode additives,making threedimensional anode designs and employing better electrolytes and functional separators to obstruct the production and shuttling of polyiodine ions are highlighted.Finally,future guidelines and directions for the development of metal-iodine batteries are proposed.展开更多
A functional interlayer based on two-dimensional(2D)porous modified vermiculite nanosheets(PVS)was obtained by acid-etching vermiculite nanosheets.The as-obtained 2D porous nanosheets exhibited a high specific surface...A functional interlayer based on two-dimensional(2D)porous modified vermiculite nanosheets(PVS)was obtained by acid-etching vermiculite nanosheets.The as-obtained 2D porous nanosheets exhibited a high specific surface area of 427 m^(2)·g^(-1)and rich surface active sites,which help restrain polysulfides(LiPSs)through good physi-cal and chemical adsorption,while simultaneously accelerating the nucleation and dissolution kinetics of Li_(2)S,effec-tively suppressing the shuttle effect.The assembled lithium-sulfur batteries(LSBs)employing the PVS-based inter-layer delivered a high initial discharge capacity of 1386 mAh·g^(-1)at 0.1C(167.5 mAh·g^(-1)),long-term cycling stabil-ity,and good rate property.展开更多
Lithium-sulfur batteries(LSBs)are promising energy storage systems due to their low cost and high energy density.However,sluggish reaction kinetics and the“shuttle effect”of lithium polysulfides(LiPSs)from sulfur ca...Lithium-sulfur batteries(LSBs)are promising energy storage systems due to their low cost and high energy density.However,sluggish reaction kinetics and the“shuttle effect”of lithium polysulfides(LiPSs)from sulfur cathode hinder the practical application of LSBs.In this work,a separator loaded with the Eu_(2)O_(3-δ)nanoparticles/carbon nanotube interlayer is designed to immobilize Li PSs and catalyze their conversion reaction.The oxygen-deficient Eu_(2)O_(3-δ)nanoparticles,with abundant catalytic sites,promote Li PSs conversion kinetics even at high current densities.Moreover,the unique 4f electronic structure of Eu_(2)O_(3-δ)effectively mitigates undesired sulfur cathode crossover,significantly enhancing the cycling performance of LSBs.Specifically,a high capacity of 620.7 mAh/g at a rate of 5 C is achieved,maintaining at 545 mAh/g after 300 cycles at 1 C.This work demonstrates the potential application of rare earth catalysts in LSBs,offering new research avenues for promoting dynamic conversion design in electrocatalysts.展开更多
Lithium-sulfur batteries(LSBs)have become a favorable contender for next-generation electrochemical energy storage systems due to their outstanding features such as high energy density,low cost,and environmental frien...Lithium-sulfur batteries(LSBs)have become a favorable contender for next-generation electrochemical energy storage systems due to their outstanding features such as high energy density,low cost,and environmental friendliness.However,the commercialization of LSBs is still characterized by critical issues such as low sulfur utilization,short cycle life,and poor rate performance,which need to be resolved.Single-atom catalysts,with their outstanding features such as ultra-high atom utilization rate close to 100%and adjustable coordination configuration,have received extensive attention in the field of lithium-sulfur battery research.In this paper,the preparation and characterization of single-atom catalysts for Li-S batteries are briefly introduced,and the latest research progress of single-atom catalysts for Li-S batteries is reviewed from three aspects:cathode,separator and anode.Finally,the key technical problems and future research directions of single-atom catalysts for lithium-sulfur batteries are also prospected,with a view to promoting the further development of commercialized LSBs.展开更多
Lithium-sulfur batteries are considered to be a new generation of high energy density batteries due to their non-toxicity,low cost and high theoretical specific capacity.However,the development of practical lithium-su...Lithium-sulfur batteries are considered to be a new generation of high energy density batteries due to their non-toxicity,low cost and high theoretical specific capacity.However,the development of practical lithium-sulfur batteries is seriously impeded by the sluggish multi-electron redox reaction of sulfur species and obstinate shuttle effect of polysulfides.In this study,a porous lanthanum oxychloride(LaOCl)nanofiber is designed as adsorbent and electrocatalyst of polysulfides to regulate the redox kinetics and suppress shuttling of sulfur species.Benefiting from the porous architecture and luxuriant active site of LaOCl nanofibers,the meliorative polarization effect and sulfur expansion can be accomplished.The LaOCl/S electrode exhibits an initial discharge specific capacity of 1112.3 mAh/g at 0.1 C and maintains a superior cycling performance with a slight decay of 0.02%per cycle over 1000 cycles at 1.0 C.Furthermore,even under a high sulfur loading of 4.6mg/cm^(2),the S cathode with LaOCl nanofibers still retains a high reversible areal capacity of 4.2 mAh/cm^(2)at 0.2 C and a stable cycling performance.Such a porous host expands the application of rare earth based catalysts in lithium-sulfur batteries and provides an alternative approach to facilitate the polysulfides conversion kinetics.展开更多
A novel[3]rotaxane,featuring two hydrogen-bonded aramide azo-macrocycles mechanically interlocked on a dumbbell with distinct recognition sites,a secondary dialkylammonium(AM)unit and a 4,4'-bipyridinium(BP)unit,h...A novel[3]rotaxane,featuring two hydrogen-bonded aramide azo-macrocycles mechanically interlocked on a dumbbell with distinct recognition sites,a secondary dialkylammonium(AM)unit and a 4,4'-bipyridinium(BP)unit,has been synthesized.This multi-stimuli-responsive[3]rotaxane exhibits unique molecular motion,with the macrocycles shuttling along the axle in response to acid-base reactions,temperature changes,solvent variations,and light irradiation.The molecular shuttle and reversibility were investigated by^(1)H NMR,2D NOESY,HRESI-MS,and UV-vis spectroscopy.This study provides a rare example of a higher order rotaxane with multi-stimuli responsiveness,highlighting its potential for multi-state control over the motion of interlocked rings on an axle.The ability to manipulate the molecular motion of the macrocycles through various external triggers offers insights for future developments in molecular machinery and adaptive materials.展开更多
Lithium-sulfur batteries(LSBs)hold significant promise as advanced energy storage systems due to their high energy density,low cost,and environmental advantages.However,despite recent advancements,their practical ener...Lithium-sulfur batteries(LSBs)hold significant promise as advanced energy storage systems due to their high energy density,low cost,and environmental advantages.However,despite recent advancements,their practical energy density still falls short of the levels required for commercial viability.The energy density is critically dependent on both sulfur loading and the amount of electrolyte used.Highsulfur loading coupled with lean electrolyte conditions presents several challenges,including the insulating nature of sulfur and Li_(2)S,insufficient electrolyte absorption,degradation of the cathode structure,severe lithium polysulfide shuttling,slow redox reaction kinetics,and instability of the Li metal anode.MXenes-based materials,with their metallic conductivity,large polar surfaces,and abundant active sites,have been identified as promising electrocatalysts to improve the redox reactions in LSBs.This review focuses on the significance and challenges associated with high-sulfur loading and lean electrolytes in LSBs,highlighting recent advancements in MXenes-based electrocatalysts aimed at optimizing sulfur cathodes and lithium anodes.It provides a comprehensive discussion on MXenes as both active materials and substrates in LSBs,with the goal of enhancing understanding of the regulatory mechanisms that govern sulfur conversion reactions and lithium plating/stripping behavior.Finally,the review explores future opportunities for MXenes-based electrocatalysts,paving the way for the practical application of LSBs.展开更多
Active sulfur dissolution and shuttle effect of lithium polysulfides(LiPSs)are the main obstacles hindering the practical application of lithium-sulfur batteries(LSBs),which is primarily induced by the direct interact...Active sulfur dissolution and shuttle effect of lithium polysulfides(LiPSs)are the main obstacles hindering the practical application of lithium-sulfur batteries(LSBs),which is primarily induced by the direct interaction between sulfur-loading cathode and liquid electrolyte.The introduction of functional interlayer within the separator and cathode is an effective strategy to stabilize the electrode/electrolyte interface reaction and improve the utilization rate of active sulfur.Herein,conductive composite nanofabrics(CCN)with multifunctional groups are employed as the interlayer of sulfur-loading cathode,in which the PMIA/PAN supporting fibers offer robust mechanical strength and high thermostable performance,and gelatin/polypyrrole functional fibers ensure high electrical conductivity and strong chemical interaction for LiPSs.As demonstrated by the experimental data and material characterizations,the presence of CCN interlayer not only blocks the shuttle behavior of LiPSs,but also strengthens the interface stability of both Li anode and sulfur-loading cathode.Interestingly,the assembled LSBs with CCN interlayer can maintain stable capacity of 686 mAh/g after 200 cycles at 0.5 A/g.This work will provide new ideas for the elaborate design of functional in terlayers/se para tors for LSBs and lithium metal batteries.展开更多
基金the financial support from the Australian Research Council (ARC) through Future Fellowship (FT210100298)DECRA Fellowship (DE230101068)+2 种基金Discovery Project (DP230100198 and DP210102215)Linkage Projects (LP220100088 and LP180100722)partially supported by AIIM FOR GOLD Grant (2017, 2018)
文摘Metal sulfides are a class of promising anode materials for sodium-ion batteries(SIBs)owing to their high theoretical specific capacity.Nevertheless,the reactant products(polysulfides)could dissolve into electrolyte,shuttle across separator,and react with sodium anode,leading to severe capacity loss and safety concerns.Herein,for the first time,gallium(Ga)-based liquid metal(LM)alloy is incorporated with MoS_(2)nanosheets to work as an anode in SIBs.The electron-rich,ultrahigh electrical conductivity,and self-healing properties of LM endow the heterostructured MoS_(2)-LM with highly improved conductivity and electrode integrity.Moreover,LM is demonstrated to have excellent capability for the adsorption of polysulfides(e.g.,Na_(2)S,Na_(2)S_(6),and S_(8))and subsequent catalytic conversion of Na_(2)S.Consequently,the MoS_(2)-LM electrode exhibits superior ion diffusion kinetics and long cycling performance in SIBs and even in lithium/potassium-ion battery(LIB/PIB)systems,far better than those electrodes with conventional binders(polyvinylidene difluoride(PVDF)and sodium carboxymethyl cellulose(CMC)).This work provides a unique material design concept based on Ga-based liquid metal alloy for metal sulfide anodes in rechargeable battery systems and beyond.
文摘Nuclear accumulation of active Smad complexes is crucial for transduction of transforming growth factor β （TGF-β）- superfamily signals from transmembrane receptors into the nucleus. It is now clear that the nucleocytoplasmic distributions of Smads, in both the absence and the presence of a TGF-β-superfamily signal, are not static, but instead the Smads are continuously shuttling between the nucleus and the cytoplasm in both conditions. This article presents the evidence for continuous nucleocytoplasmic shuttling of Smads. It then reviews different mechanisms that have been proposed to mediate Smad nuclear import and export, and discusses how the Smad steady-state distributions in the absence and the presence of a TGF-β-superfamily signal are established. Finally, the biological relevance of continuous nucleocytoplasmic shuttling for signaling by TGF-β superfamily members is discussed.
基金the National Natural Science Foundation of China(No.21574097).
文摘Stereoblock polypropyienes bearing isotactic,atactic,and syndictactic polypropylene segments were successfully prepared by dry methylaluminoxane activated binary catalysts system,Ph2CFluCpZrCl2 and {Me2Si(2,5-Me2-3-(2-MePh)-cyclopento[2,3-b]thiophen-6-yl)2}ZCl2,in the presence of iBu3Al as a chain shutting agent.by studying the catalyst activity,chain transfer efficiency,and reversility of chain transfer reaction of each catalyst system,as well as the molecular weight and polydispersity of the resulting polymers,the allyl exchange reactions between the zirconium catalyst and different main-group metal alky were estimated,respectvely.Based on the optimized react condition,the chain shuttling polymerization was conducted by binary catalyst system in the presence of iBu3Al under both atmospheric and high pressure.Resultant polymers were identified as stereoblock polypropylenes according to microstructure and physical properties analyses by 13C{1H}-NMR,DsC,and GPC.
基金financially supported by Soft Science Research Project of Guangdong Province(No.2017B030301013)the Shenzhen Science and Technology Research(Grant No.JCYJ20170818085823773,ZDSYS201707281026184)+1 种基金China Postdoctoral Science Foundation(2019M660317)the National Science Foundation of China(No.U1864213)。
文摘Sodium-oxygen batteries(Na-O_(2))have attracted extensive attention as promising energy storage systems due to their high energy density and low cost.Redox mediators are often employed to improve Na-O_(2) battery performance,however,their effect on the formation mechanism of the oxygen reduction product(NaO_(2))is still unclear.Here,we have investigated the formation mechanism of NaO_(2) during the discharge process in the presence of a redox mediator with the help of atomic/nano-scale in-situ characterization tools used in concert(e.g.atomic force microscope,electrochemical quartz crystal microbalance(EQCM)and laser nano-particle analyzer).As a result,real-time observations on different time scales show that by shuttling electrons to the electrolyte,the redox mediator enables formation of NaO_(2) in the solution-phase instead of within a finite region near the electrode surface.These findings provide new fundamental insights on the understanding of Na-O_(2) batteries and new consequently perspectives on designing high performance metal-O_(2) batteries and other related functions.
基金supported by the National Natural Science Foundation of China(Nos.22025503,21790361 and 21871084)Shanghai Municipal Science and Technology Major Project(No.2018SHZDZX03)+3 种基金the Fundamental Research Funds for the Central Universitiesthe Program of Introducing Talents of Discipline to Universities(No.B16017)the Shanghai Science and Technology Committee(No.17520750100)funding from China Postdoctoral Science Foundation funded project(No.J100–5R-20130)。
文摘A bistable[2]rotaxane with a conformation-adaptive macrocycle bearing a 9,14-diphenyl-9,14-dihydrodibenzo[a,c]phenazine(DPAC)unit was synthesized,which could be utilized to optical probe the molecular shuttling motion of the functionalized rotaxane system.The UV-vis,^(1) H NMR and PL spectroscopic data clearly demonstrated that the DPAC ring was interlocked onto the thread and the fluorescence intensity of the DPAC unit in the macrocycle was effectively regulated by the location change of the macrocycle along the thread under acid/base stimulation,which was attributed to the modulation of the intramolecular photo-induced electron transfer between the DPAC unit and the methyltriazole(MTA)unit.This bistable rotaxane system containing a conformation-adaptive fluorophore unit in the macrocycle moiety opens an alternative way to design functional bistable mechanically interlocked molecules.
文摘Targeting early steps in amyloid-beta production：Alzheimer’s disease（AD）has a long history as the＂amyloid deposit＂disorder.Many disorders are now known to be caused by proteinβ-sheet misfolding and aggregation（e.g.,Parkinson’s disease：α-synuclein;Huntington’s disease：Huntingtin;
文摘P68 RNA helicase is a prototypical DEAD box RNA helicase. The protein plays a very important role in early organ development and maturation. Consistent with the function of the protein in transcriptional regulation and pre-mRNA splicing, p68 was found to predominately localize in the cell nucleus. However, recent experiments demon- strate a transient cytoplasmic localization of the protein. We report here that p68 shuttles between the nucleus and the cytoplasm. The nucleocytoplasmic shuttling of p68 is mediated by two nuclear localization signal and two nuclear exporting signal sequence elements. Our experiments reveal that p68 shuttles via a classical RanGTPase-dependent pathway.
基金supported by Science and Technology Project of Jilin Provincial Education Department(grant no.JJKH20221160KJ)Jilin Province Science and Technology Department(grant no.20230402059GH)+1 种基金The Swedish Foundation for International Cooperation in Research and Higher Education(grant no.KO2017-7351)Swedish Energy Agency(Project no.P2020-90216).
文摘Although lithium iodide(LiI)as a redox mediator(RM)can decrease the overpotential in Li-O_(2)batteries,the stability of the Li anode is still one critical issue due to the redox shuttling.Here,we firstly present a novel approach for generating Ag and LiTFSI enriched Li anode(designated as ALE@Li anode)via a spontaneous substitution between pure Li and bis(trifluoromethanesulfonyl)imide silver,in a LiI-participated Li-O_(2)cell.It can induce the generation of a lithiophilic solid electrolyte interphase(SEI)enriched with Ag,F,and N species(e.g.,Ag_(2)O,Li-Ag alloy,LiF,and Li_(3)N)during cell operation,which contributes to promoting the electrochemical performance through the shuttling inhibition.Compared to a cell with a bare Li anode,the one with as-prepared ALE@Li anode shows an enhanced cyclability,a considerable rate capability,and a good reversibility.In addition,a synchrotron X-ray computed tomography technique is employed to investigate the inhibition mechanism for shuttling effect by monitoring the morphological evolution on the cell interfaces.Therefore,this work highlights the deliberate design in the modified Li anode in an easy-to-operate and cost-effective way as well as providing guidance for the construction of artificial SEI layers to suppress the redox shuttling of RMs in Li-O_(2)batteries.
基金supported by the open research fund of the State Key Laboratory of Organic Electronics and Information Displays,the Startup Foundation for Introducing Talent of NUIST(Nos.2021r090 and 2021r091)Jiangsu Provincial Scientific Research and Practice Innovation Program(Nos.SJCX23_0420 and SJCX23_0421).
文摘Lithium-sulfur(Li-S)batteries,known for their high energy density,are attracting extensive research interest as a promising next-generation energy storage technology.However,their widespread use has been hampered by certain issues,including the dissolution and migration of polysulfides,along with sluggish redox kinetics.Metal sulfides present a promising solution to these obstacles regarding their high electrical conductivity,strong chemical adsorption with polysulfides,and remarkable electrocatalytic capabilities for polysulfide conversion.In this review,the recent progress on the utilization of metal sulfide for suppressing polysulfide shuttling in Li-S batteries is systematically summarized,with a special focus on sulfur hosts and functional separators.The critical roles of metal sulfides in realizing high-performing Li-S batteries have been comprehensively discussed by correlating the materials’structure and electrochemical performances.Moreover,the remaining issues/challenges and future perspectives are highlighted.By offering a detailed understanding of the crucial roles of metal sulfides,this review dedicates to contributing valuable knowledge for the pursuit of high-efficiency Li-S batteries based on metal sulfides.
基金financially supported by the University Natural Science Research Key Project of Anhui Province(Nos.KJ2021A1091,2023AH051619)Innovation and Entrepreneurship Training Program for College Students(No.202310377030)Scientific Research Start Foundation Project of Chuzhou University(No.2022qd011)。
文摘Metal organic frameworks(MOFs)are crystalline materials with three-dimensional porous network structure.They are obtained by self-assembly of coordinate bond with metal ions as the nodes and organic ligands as the connecting chains.MOFs have attracted extensive attention from researchers over the years due to their clear pore and rich topological structure.As the typical powder materials,a specific separator manufacturing process must be possessed when incorporating MOFs into lithium sulfur batteries separator.This mini review summarized the manufacturing process of MOFs separator for LSBs in recent years,and summed up the effects and mechanisms of separators prepared by various separator-forming processes on the performance of LSBs,the potential for industrialization of different separator manufacturing processes is also mentioned briefly.
基金grants from the National Natural Science Foundation of China (31720103914 and 31390422).
文摘Many geminivirus C4 proteins induce severe developmental abnormalities in plants.We previously demon- strated that Tomato leaf curl Yunnan virus (TLCYnV)C4 induces plant developmental abnormalities at least partically by decreasing the accumulation of NbSKη,an ortholog of Arabidopsis BIN2 kinase involved in the brassinosteroid signaling pathway,in the nucleus through directing it to the plasma membrane.However, the molecular mechanism by which the membrane-associated C4 modifies the localization of NbSKη in the host cell remains unclear.Here,we show that TLCYnV C4 is a nucleocytoplasmic shuttle protein,and that C4 shuttling is accompanied by nuclear export of NbSKTI.TLCYnV C4 is phosphorylated by NbSKη in the nucleus,which promotes myristoylation of the viral protein.Myristoylation of phosphorylated C4 favors its interaction with exportin-α(XPO I);which in turn facilitates nuclear export of the C4/NbSKTI complex. Supporting this model,chemical inhibition of N-myristoyltransferases or exportin-α enhanced nuclear retention of C4,and mutations of the putative phosphorylation or myristoylation sites in C4 resulted in increased nuclear retention ofrC4 and thus decreased severity of C4-induced developmental abnormalities. The impact of C4 on development is also lessened when a nuclear localization signal or a nuclear export signal is added to its C-terminus,restricting it to a specific cellular niche and therefore impairing nucleocytoplasmic shuttling.Taken together,our results suggest that nucleocytoplasmic shuttling of TLCYnV C4,enabled by phosphorylation by NbSKη,myristoylation,and interaction with exportin-α is critical for its function as a pathogenicity factor.
基金supported by the National Natural Science Foundation of China(grants 81720108032 and 81930109 to Haiping Hao,82073926 to Hong Wang,and 82073928 to Guangji Wang)the National Key Research and Development Programme of China(2021YFA1301300 to Haiping Hao)+2 种基金Leading Technology Foundation Research Project of Jiangsu Province(grant BK20192005 to Guangji Wang,China)the Project Program of State Key Laboratory of Natural Medicines(China Pharmaceutical University,SKLNMZZ202202 to Haiping Hao)Sanming Project of Medicine in Shenzhen(SZSM201801060 to Guangji Wang,China)。
文摘Farnesoid X receptor(FXR)is widely accepted as a promising target for various liver diseases;however,panels of ligands in drug development show limited clinical benefits,without a clear mechanism.Here,we reveal that acetylation initiates and orchestrates FXR nucleocytoplasmic shuttling and then enhances degradation by the cytosolic E3 ligase CHIP under conditions of liver injury,which represents the major culprit that limits the clinical benefits of FXR agonists against liver diseases.Upon inflammatory and apoptotic stimulation,enhanced FXR acetylation at K217,closed to the nuclear location signal,blocks its recognition by importin KPNA3,thereby preventing its nuclear import.Concomitantly,reduced phosphorylation at T442 within the nuclear export signals promotes its recognition by exportin CRM1,and thereby facilitating FXR export to the cytosol.Acetylation governs nucleocytoplasmic shuttling of FXR,resulting in enhanced cytosolic retention of FXR that is amenable to degradation by CHIP.SIRT1 activators reduce FXR acetylation and prevent its cytosolic degradation.More importantly,SIRT1 activators synergize with FXR agonists in combating acute and chronic liver injuries.In conclusion,these findings innovate a promising strategy to develop therapeutics against liver diseases by combining SIRT1 activators and FXR agonists.
基金supported by the National Natural Science Foundation of China(No.52371240)the Natural Science Foundation of Jiangsu Province(No.BK20230556)+2 种基金China Postdoctoral Science Foundation(No.2022M722686)Jiangsu Funding Program for Excellent Postdoctoral Talent(No.2023ZB701)The Big Data Computing Center of Southeast University.
文摘Metal-iodine batteries have attracted widespread attention due to their long cycle life,high energy density,remarkable charging capability and low self-discharge rate.Nevertheless,this development is hampered by the challenges of the iodine cathode and metal anode,including the hydrogen evolution reaction(HER),sluggish kinetics,shuttle effect of polyiodine ion at the cathode and dendrite formation,corrosion and passivation at the anode.This review summarizes recent developments in metaliodine batteries,including zinc-iodine batteries,lithiumiodine batteries,sodium-iodine batteries,etc.The challenges in the cathode,anode,electrolyte and separator of metal-iodine batteries are discussed,along with the corresponding design and synthesis strategies and specific methods to improve the electrochemical performance.Selecting appropriate cathode hosts,constructing surface protective layers,adding anode additives,making threedimensional anode designs and employing better electrolytes and functional separators to obstruct the production and shuttling of polyiodine ions are highlighted.Finally,future guidelines and directions for the development of metal-iodine batteries are proposed.
文摘A functional interlayer based on two-dimensional(2D)porous modified vermiculite nanosheets(PVS)was obtained by acid-etching vermiculite nanosheets.The as-obtained 2D porous nanosheets exhibited a high specific surface area of 427 m^(2)·g^(-1)and rich surface active sites,which help restrain polysulfides(LiPSs)through good physi-cal and chemical adsorption,while simultaneously accelerating the nucleation and dissolution kinetics of Li_(2)S,effec-tively suppressing the shuttle effect.The assembled lithium-sulfur batteries(LSBs)employing the PVS-based inter-layer delivered a high initial discharge capacity of 1386 mAh·g^(-1)at 0.1C(167.5 mAh·g^(-1)),long-term cycling stabil-ity,and good rate property.
基金the financial support from the National Natural Science Foundation of China(Nos.52104312,22278329,22271229,22105153)Qin Chuangyuan Talent Project of Shaanxi Province(Nos.2021QCYRC4-43,QCYRCXM-2022-308)the State Key Laboratory for Electrical Insulation and Power Equipment(No.EIPE23125)。
文摘Lithium-sulfur batteries(LSBs)are promising energy storage systems due to their low cost and high energy density.However,sluggish reaction kinetics and the“shuttle effect”of lithium polysulfides(LiPSs)from sulfur cathode hinder the practical application of LSBs.In this work,a separator loaded with the Eu_(2)O_(3-δ)nanoparticles/carbon nanotube interlayer is designed to immobilize Li PSs and catalyze their conversion reaction.The oxygen-deficient Eu_(2)O_(3-δ)nanoparticles,with abundant catalytic sites,promote Li PSs conversion kinetics even at high current densities.Moreover,the unique 4f electronic structure of Eu_(2)O_(3-δ)effectively mitigates undesired sulfur cathode crossover,significantly enhancing the cycling performance of LSBs.Specifically,a high capacity of 620.7 mAh/g at a rate of 5 C is achieved,maintaining at 545 mAh/g after 300 cycles at 1 C.This work demonstrates the potential application of rare earth catalysts in LSBs,offering new research avenues for promoting dynamic conversion design in electrocatalysts.
基金supported by the Shenzhen Key Basic Research Project:Ionic Liquid-Assisted Synthesis of Single Catalyst and Its Applications in Lithium Sulfur Batteries(GXWD20220817125846003)Major Instrument Project of National Natural Science Foundation of China(62127807)Shenzhen Sustainable Development Special Project(KCXFZ20201221173000001).
文摘Lithium-sulfur batteries(LSBs)have become a favorable contender for next-generation electrochemical energy storage systems due to their outstanding features such as high energy density,low cost,and environmental friendliness.However,the commercialization of LSBs is still characterized by critical issues such as low sulfur utilization,short cycle life,and poor rate performance,which need to be resolved.Single-atom catalysts,with their outstanding features such as ultra-high atom utilization rate close to 100%and adjustable coordination configuration,have received extensive attention in the field of lithium-sulfur battery research.In this paper,the preparation and characterization of single-atom catalysts for Li-S batteries are briefly introduced,and the latest research progress of single-atom catalysts for Li-S batteries is reviewed from three aspects:cathode,separator and anode.Finally,the key technical problems and future research directions of single-atom catalysts for lithium-sulfur batteries are also prospected,with a view to promoting the further development of commercialized LSBs.
基金supported by the Scientific Research Program Funded by Education Department of Shaanxi Provincial Government(No.22JK0411)the Natural Science Basic Research Program of Shaanxi Province(No.2023-JC-QN-0165)the National Natural Science Foundation of China(No.21603109).
文摘Lithium-sulfur batteries are considered to be a new generation of high energy density batteries due to their non-toxicity,low cost and high theoretical specific capacity.However,the development of practical lithium-sulfur batteries is seriously impeded by the sluggish multi-electron redox reaction of sulfur species and obstinate shuttle effect of polysulfides.In this study,a porous lanthanum oxychloride(LaOCl)nanofiber is designed as adsorbent and electrocatalyst of polysulfides to regulate the redox kinetics and suppress shuttling of sulfur species.Benefiting from the porous architecture and luxuriant active site of LaOCl nanofibers,the meliorative polarization effect and sulfur expansion can be accomplished.The LaOCl/S electrode exhibits an initial discharge specific capacity of 1112.3 mAh/g at 0.1 C and maintains a superior cycling performance with a slight decay of 0.02%per cycle over 1000 cycles at 1.0 C.Furthermore,even under a high sulfur loading of 4.6mg/cm^(2),the S cathode with LaOCl nanofibers still retains a high reversible areal capacity of 4.2 mAh/cm^(2)at 0.2 C and a stable cycling performance.Such a porous host expands the application of rare earth based catalysts in lithium-sulfur batteries and provides an alternative approach to facilitate the polysulfides conversion kinetics.
基金supported by the National Natural Science Foundation of China(No.22271202 to L.Yuan,No.22201193 to X.Li)the Sichuan Science and Technology Program(No.2023NSFSC0109 to X.Li)+2 种基金the Fundamental Research Funds for the Central Universities and the Hundred Talent Program of Sichuan University(No.YJ2021158 to X.Li)Sichuan University Interdisciplinary Innovation Fund(X.Li)Open Project of State Key Laboratory of Supramolecular Structure and Materials(No.SKLSSM2024037)。
文摘A novel[3]rotaxane,featuring two hydrogen-bonded aramide azo-macrocycles mechanically interlocked on a dumbbell with distinct recognition sites,a secondary dialkylammonium(AM)unit and a 4,4'-bipyridinium(BP)unit,has been synthesized.This multi-stimuli-responsive[3]rotaxane exhibits unique molecular motion,with the macrocycles shuttling along the axle in response to acid-base reactions,temperature changes,solvent variations,and light irradiation.The molecular shuttle and reversibility were investigated by^(1)H NMR,2D NOESY,HRESI-MS,and UV-vis spectroscopy.This study provides a rare example of a higher order rotaxane with multi-stimuli responsiveness,highlighting its potential for multi-state control over the motion of interlocked rings on an axle.The ability to manipulate the molecular motion of the macrocycles through various external triggers offers insights for future developments in molecular machinery and adaptive materials.
基金supported by the Research Funding of Hangzhou International Innovation Institute of Beihang University(Grant No.2024KQ102 and 2024KQ131)the National Natural Science Foundation of China(Grant No.524B2020,51925202,U22A20141,52432004,U23A20575,52472183,and 22379039).
文摘Lithium-sulfur batteries(LSBs)hold significant promise as advanced energy storage systems due to their high energy density,low cost,and environmental advantages.However,despite recent advancements,their practical energy density still falls short of the levels required for commercial viability.The energy density is critically dependent on both sulfur loading and the amount of electrolyte used.Highsulfur loading coupled with lean electrolyte conditions presents several challenges,including the insulating nature of sulfur and Li_(2)S,insufficient electrolyte absorption,degradation of the cathode structure,severe lithium polysulfide shuttling,slow redox reaction kinetics,and instability of the Li metal anode.MXenes-based materials,with their metallic conductivity,large polar surfaces,and abundant active sites,have been identified as promising electrocatalysts to improve the redox reactions in LSBs.This review focuses on the significance and challenges associated with high-sulfur loading and lean electrolytes in LSBs,highlighting recent advancements in MXenes-based electrocatalysts aimed at optimizing sulfur cathodes and lithium anodes.It provides a comprehensive discussion on MXenes as both active materials and substrates in LSBs,with the goal of enhancing understanding of the regulatory mechanisms that govern sulfur conversion reactions and lithium plating/stripping behavior.Finally,the review explores future opportunities for MXenes-based electrocatalysts,paving the way for the practical application of LSBs.
基金supported by National Natural Science Foundation of China(No.22309029)Guangdong Basic and Applied Basic Research Foundation(No.2021A1515110089)+2 种基金Dongguan Social Development Technology Foundation(No.20231800907933)Collaborative Innovation Center of Marine Science and Technology of Hainan University(No.XTCX2022HYC14)Start-up Research Foundation of Hainan University(No.KYQD(ZR)-23069)。
文摘Active sulfur dissolution and shuttle effect of lithium polysulfides(LiPSs)are the main obstacles hindering the practical application of lithium-sulfur batteries(LSBs),which is primarily induced by the direct interaction between sulfur-loading cathode and liquid electrolyte.The introduction of functional interlayer within the separator and cathode is an effective strategy to stabilize the electrode/electrolyte interface reaction and improve the utilization rate of active sulfur.Herein,conductive composite nanofabrics(CCN)with multifunctional groups are employed as the interlayer of sulfur-loading cathode,in which the PMIA/PAN supporting fibers offer robust mechanical strength and high thermostable performance,and gelatin/polypyrrole functional fibers ensure high electrical conductivity and strong chemical interaction for LiPSs.As demonstrated by the experimental data and material characterizations,the presence of CCN interlayer not only blocks the shuttle behavior of LiPSs,but also strengthens the interface stability of both Li anode and sulfur-loading cathode.Interestingly,the assembled LSBs with CCN interlayer can maintain stable capacity of 686 mAh/g after 200 cycles at 0.5 A/g.This work will provide new ideas for the elaborate design of functional in terlayers/se para tors for LSBs and lithium metal batteries.
