The external stimulus response strategy has been evolved rapidly in the field of olefin polymerization.In this work,we modularly synthesized three types of double stimulus responsiveα-diimine palladium catalysts,comb...The external stimulus response strategy has been evolved rapidly in the field of olefin polymerization.In this work,we modularly synthesized three types of double stimulus responsiveα-diimine palladium catalysts,combining redox regulation and other regulation together,such as light,Lewis acid and alkali cations.The catalytic activities and the molecular weight of polyethylene products can be regulated for 4 times in ethylene polymerization.These palladium complexes were also used for the copolymerization reaction of ethylene and polar monomers,such as methyl 10-undecylenate and methyl acrylate,effectively regulating the catalytic activities,the molecular weight and polar monomer incorporation of the prepared copolymers.The research on these dual-regulated palladium complexes makes full use of prepared catalysts and provides new inspirations for regulating olefin polymerization.展开更多
Miniature devices comprising stimulus-responsive hydrogels with high environmental adaptability are now considered competitive candidates in the fields of biomedicine,precise sensors,and tunable optics.Reliable and ad...Miniature devices comprising stimulus-responsive hydrogels with high environmental adaptability are now considered competitive candidates in the fields of biomedicine,precise sensors,and tunable optics.Reliable and advanced fabricationmethods are critical formaximizing the application capabilities ofminiature devices.Light-based three-dimensional(3D)printing technology offers the advantages of a wide range of applicable materials,high processing accuracy,and strong 3D fabrication capability,which is suitable for the development of miniature devices with various functions.This paper summarizes and highlights the recent advances in light-based 3D-printed miniaturized devices,with a focus on the latest breakthroughs in lightbased fabrication technologies,smart stimulus-responsive hydrogels,and tunable miniature devices for the fields of miniature cargo manipulation,targeted drug and cell delivery,active scaffolds,environmental sensing,and optical imaging.Finally,the challenges in the transition of tunable miniaturized devices from the laboratory to practical engineering applications are presented.Future opportunities that will promote the development of tunable microdevices are elaborated,contributing to their improved understanding of these miniature devices and further realizing their practical applications in various fields.展开更多
Diverse natural organisms possess stimulus-responsive structures to adapt to the surrounding environment.Inspired by nature,researchers have developed various smart stimulus-responsive structures with adjustable prope...Diverse natural organisms possess stimulus-responsive structures to adapt to the surrounding environment.Inspired by nature,researchers have developed various smart stimulus-responsive structures with adjustable properties and functions to address the demands of ever-changing application environments that are becoming more intricate.Among many fabrication methods for stimulus-responsive structures,femtosecond laser direct writing(FsLDW)has received increasing attention because of its high precision,simplicity,true three-dimensional machining ability,and wide applicability to almost all materials.This paper systematically outlines state-of-the-art research on stimulus-responsive structures prepared by FsLDW.Based on the introduction of femtosecond laser-matter interaction and mainstream FsLDW-based manufacturing strategies,different stimulating factors that can trigger structural responses of prepared intelligent structures,such as magnetic field,light,temperature,pH,and humidity,are emphatically summarized.Various applications of functional structures with stimuli-responsive dynamic behaviors fabricated by FsLDW,as well as the present obstacles and forthcoming development opportunities,are discussed.展开更多
AM-AMPS-TAC polymers with different charge distribution are synthesized using acrylamide(AM),2-acrylamido-2-methylpropanesulfonate(AMPS)and 3-acrylamidopropyl trimethylammonium(TAC)at different feed ratios by polymeri...AM-AMPS-TAC polymers with different charge distribution are synthesized using acrylamide(AM),2-acrylamido-2-methylpropanesulfonate(AMPS)and 3-acrylamidopropyl trimethylammonium(TAC)at different feed ratios by polymerization in solution.The salt-responsive behavior,reasons leading to salt-responsiveness,and effects of polymers molecular structure on salt-responsiveness are studied by laboratory experiments to find out the adaptability of the polymers.Rheology test under stepwise shear mode shows that the AM-AMPS-TAC polymers have salt responsiveness,and the closer the feeds of AMPS and ATC,the more significant the salt responsiveness will be.Conformation change of polymers molecular chain under salt stimulus is studied by turbidity test and micro-morphology analysis,and the responsive mechanism is further investigated by intrinsic viscosity test and copolymer composition analysis.Results indicate that the salt-responsive behavior of AM-AMPS-TAC polymers derives from the"curled to expanded"transition of chain conformation under salt stimulus,and this transition is led by the screening effect of salt which weakens polymers intramolecular ionic bond.Application in saturated saltwater drilling fluid shows that the AM90-AMPS5-TAC5 polymer has the best salt-tolerance and temperature-tolerance when used together with fluid loss controller PAC-Lv.The drilling fluid saturated with NaCl can maintain stable viscosity,good dispersion and low fluid loss for long time under 150℃.展开更多
Polymeric nanoparticles with unique properties are regarded as the most promising materials for biomedical applications including drug delivery and in vitro/in vivo imaging.Among them,stimulus-responsive polymeric nan...Polymeric nanoparticles with unique properties are regarded as the most promising materials for biomedical applications including drug delivery and in vitro/in vivo imaging.Among them,stimulus-responsive polymeric nanoparticles,usually termed as "intelligent" nanoparticles,could undergo structure,shape,and property changes after being exposed to external signals including pH,temperature,magnetic field,and light,which could be used to modulate the macroscopical behavior of the nanoparticles.This paper reviews the recent progress in stimulus-responsive nanoparticles used for drug delivery and in vitro/in vivo imaging,with an emphasis on double/multiple stimulus-responsive systems and their biomedical applications.展开更多
Luminogens that exhibit stimulus-responsive room temperature phosphorescence(RTP)have attracted significant attention for their applications in a wide range of fields such as data storage,sensors,and bio-imaging.Howev...Luminogens that exhibit stimulus-responsive room temperature phosphorescence(RTP)have attracted significant attention for their applications in a wide range of fields such as data storage,sensors,and bio-imaging.However,very few such materials are known,partly because of the unclear internal mechanism.In this review,we summarize recent advances in the field of stimulusresponsive RTP in purely organic luminogens,focusing on their unique emission behaviors and internal mechanisms governing the phenomena.We also attempt to identify the relationship between the mechanism,luminogens,and possible applications.展开更多
Stimulus-responsive energy storage devices,which can respond to external stimuli,such as heat,pH,moisture,pressure,or electric field,have recently attracted intensive attention,aiming at the ever-increasing demand for...Stimulus-responsive energy storage devices,which can respond to external stimuli,such as heat,pH,moisture,pressure,or electric field,have recently attracted intensive attention,aiming at the ever-increasing demand for safe batteries and smart electronics.The most typical stimulus-responsive materials are polymers that can change their conformation by forming and destroying secondary forces,including hydrogen bonds and electrostatic interactions in response to external stimuli,accompanied by changes in the intrinsic properties such as conductivity and hydrophobicity.Although the applications of stimulus-responsive functions in rechargeable batteries are still in the early stage because of the complexity and compatibility of battery architectures,many new concepts of regulating the polymer structures upon applications of stimuli have already been developed.In this review,we discuss the recent progress of stimulus-responsive polymers on energy storage devices featuring thermal protection and intelligent scenarios,with a focus on the detailed structural transformations of polymers under a given stimulus and the corresponding changes in battery performance.Finally,we present perspectives on the current limitations and future research directions of stimulus-responsive polymers for energy storage devices.展开更多
Circularly polarized luminescence(CPL)has gained considerable attention in various systems and has rapidly developed into an emerging research field.To meet the needs of actual applications in diverse fields,a high lu...Circularly polarized luminescence(CPL)has gained considerable attention in various systems and has rapidly developed into an emerging research field.To meet the needs of actual applications in diverse fields,a high luminescence dissymmetry factor(glum)and tunable optical performance of CPL would be the most urgent pursuit for researchers.Accordingly,many emerging CPL materials and various strategies have been developed to address these critical issues.Emissive cholesteric liquid crystals(CLCs),that is,luminescent self-organized helical superstructures,are considered to be ideal candidates for constructing CPL-active materials,as they not only exhibit high glum values,but also enable flexible optical control of CPL.This review mainly summarizes the characteristics of CPL based on CLCs as the bulk phase doped with different emitters,including aggregated induced emission molecules,conventional organic small molecules,polymer emitters,metal-organic complex emitters,and luminescent nanoparticles.In addition,the recent significant progress in stimulus-responsive CPL based on emissive CLCs in terms of several types of stimuli,including light,electricity,temperature,mechanical force,and multiple stimuli is presented.Finally,a short perspective on the opportunities and challenges associated with CPL-active materials based on the CLC field is provided.This review is anticipated to offer new insights and guidelines for developing CLC-based CPL-active materials for broader applications.展开更多
Nanomaterials that can sequentially respond to internal and external stimuli,functioning as a sequential gate,have great potential for targeting different aspects of antitumor immunity.Herein,we construct a mannose-mo...Nanomaterials that can sequentially respond to internal and external stimuli,functioning as a sequential gate,have great potential for targeting different aspects of antitumor immunity.Herein,we construct a mannose-modified,pH and reactive oxygen species(ROS) sequential-responsive,transformable dualimmunofunction nanoprodrug(MpRTNP).This nanoprodrug encapsulates a transforming growth factor-β(TGF-β) receptor inhibitor SD-208(MpRTNP@SD),to simultaneously alleviate the immunosuppressive effects of TGF-β and tumor-associated macrophages(TAMs).In the weakly acidic tumor microenvironment(TME),the vesicle-micelle morphology transformation occurs owing to the protonation of PC7A,which is accompanied by SD-208 release to inhibit cancer-associated fibroblasts and regulatory T cells.The transformed micelles then target TAMs via mannose receptor-media ted endocytosis.Upon laser irradiation,the thioketal linker is cleaved,releasing conjugated chlorin e6 and generating ROS,which facilitates TAM polarization.The PC7A^(+) segment activates the stimulator of the interferon gene in TAMs with elevated phosphorylation of TANK binding kinase 1 and interferon regulatory factor 3,and type I interferon secretion.MpRTNP@SD displays superior abscopal effects and robust antitumor immunity,as evidenced by increased CD8^(+)/CD4^(+) T cell infiltration and reduced regulatory T cell(Treg) ratios.Mouse survival time is prolonged after combination with the CD47 antibody.This study provides a novel strategy for potent antitumor immunotherapy through pH and ROS sequential-gated spatiotemporal regulation of the TME.展开更多
Stimulus-responsive liquid foams have gained much attention for use in various industrial applications.However,it remains challenging to construct such systems with integrated functionality of easy preparation,high st...Stimulus-responsive liquid foams have gained much attention for use in various industrial applications.However,it remains challenging to construct such systems with integrated functionality of easy preparation,high stability,high foaming ability,and rapid on-demand degradation.Herein,by combining the Hofmeister effect and nanotechnology,a promising ultrastable and photoresponsive liquid foam was prepared that had a lifetime of several months and could be destroyed on demand in a few minutes.Specifically,the system was prepared by simply mixing a gelatine solution containing black phosphorus nanosheets(BPNs)and kosmotropic anions in the Hofmeister series with air in one step using only two syringes,and there were no chemical modifications or crosslinking agents required.The kosmotropic anions induced stronger hydrophobic interactions,bundling within molecular chains,and blockage of foam drainage channels,which significantly improved the foaming ability and the lifetime and mechanical properties of the foam.Moreover,rational structure design realized a promising on-demand degradation mechanism via a cascading“light trigger-heat generation-Marangoni flow generation”process occurring on the bubble surfaces.On this basis,the BPNs converted light into thermal energy,which induced Marangoni flow driven by surface tension gradients along the gas-liquid interfaces,and the bubble film ruptured within seconds upon light illumination.The designed stimulus-response systems combined stable,fast and repeatable processes without sacrificing the foaming abilities,thus providing a general way to control the stabilities of foams,bubbles and films.展开更多
This work develops a protein imprinted nanosphere with varied recognition specificity for bovine serum albumin(BSA)and lysozyme(Lyz)under different UV light through a gradient dual crosslinked imprinting strategy(i.e....This work develops a protein imprinted nanosphere with varied recognition specificity for bovine serum albumin(BSA)and lysozyme(Lyz)under different UV light through a gradient dual crosslinked imprinting strategy(i.e.,covalent crosslinking and dynamic reversible crosslinking).The imprinting cavities are initially constructed using irreversible covalent crosslinking to specifically recognize BSA,and then the coumarin residues in the imprinting cavities are crosslinked under 365 nm UV light to further imprint Lyz,because Lyz has smaller size than BSA.Since the photo-crosslinking of coumarin is a reversible reaction,the imprinting cavities of Lyz can be de-crosslinked under 254 nm UV light and restore the imprinting cavities of BSA.Moreover,the N-isopropyl acrylamide(NIPAM)and pyrrolidine residues copolymerized in the polymeric surface of the nanospheres are temperature-and p H-responsive respectively.Therefore,the protein rebinding and release behaviors of the nanospheres are controlled by external temperature and p H.As a result,the materials can selectively separate BSA from real bovine whole blood and Lyz from egg white under different UV light.This study may provide a new strategy for construction of protein imprinted materials with tunable specificity for different proteins.展开更多
Shot and step response measurements were carried out with inert bed and adsorption bed both under iso-thermal conditions.Parameter values were determined from a time domain analysis of the measured inputand response s...Shot and step response measurements were carried out with inert bed and adsorption bed both under iso-thermal conditions.Parameter values were determined from a time domain analysis of the measured inputand response signal.Sensitivity test in the parameter values showed that shot response measurements maygive more reliable parameter values than step measurements.Since Kubin[1]and Kucera[2]proposed a parameter estimation technique based on a moment methodfor adsorption system,attention has been focused on dynamic input-output measurements with variouspacked bed systems for the parameter estimation.The object of this work is to compare shot and step re-sponse measurements and see which measurement gives more reliable parameter values.展开更多
Insufficient intratumoral retention of nanomedicines remains the major challenge for broad implementation in clinical sets.Herein,we proposed a legumain-triggered aggregable gold nanoparticle(GNP)delivery platform(GNP...Insufficient intratumoral retention of nanomedicines remains the major challenge for broad implementation in clinical sets.Herein,we proposed a legumain-triggered aggregable gold nanoparticle(GNP)delivery platform(GNPs-A&C).GNPs-A&C could form intratumoral or intracellular aggregates in response to the overexpressed legumain.The aggregates with size increase not only could reduce back-flow from interstitial space to peripheral bloodstream but also could restrict the cellular exocytosis,leading to enhanced intratumoral retention.In vitro studies demonstrated that GNPs-A&C possessed an excellent legumain responsiveness and the increased size was closely relevant with legumain expression.In vivo studies demonstrated GNPs-A&C possessed slower clearance rate and much higher intratumoral retention within legumain-overexpressed tumor compared to non-aggregable NPs,regardless of intravenous or intratumoral injection.More importantly,this delivery platform significantly improved the chemotherapeutic effect of doxorubicin(DOX)towards subcutaneous xenograft C6 tumor.The effectiveness of this stimulus-responsive aggregable delivery system provides a thinking for designing more intelligent size-tunable nanomedicine that can substantially improve intratumoral retention.展开更多
Solid-state materials that exhibit pressure stimulus-response characteristics in a manner of emission signal,known as piezochromic luminescence(PCL),demonstrate great potential in photoelectric devices.The weakened lu...Solid-state materials that exhibit pressure stimulus-response characteristics in a manner of emission signal,known as piezochromic luminescence(PCL),demonstrate great potential in photoelectric devices.The weakened luminescence and insignificant color change in the aggregation state,however,hampers their practical applications.Herein,a highly emissive coordination polymer,[Zn2(H4TTPE)(H2O)4]·H2O(CUST-805),is successfully constructed by employing an AIE-active chromophore as the building block.The structural characterization and photophysical properties are systematically studied.Owing to intrinsic twisted conformation and AIE feature of tetraphenylethylene-tetrazole ligand,CUST-805 achieves the visible and reversible PCL from blue to green switched by different external stimuli.The transformation between crystalline and amorphous states is proved to be the origin of present PCL behavior.Moreover,on basis of electron and energy transfer quenching mechanism,the highly selective and sensitive sensor based on CUST-805 is realized,showing the low detection limit of 0.29 ppm towards 2,4,6-trinitrophenol.展开更多
Shape memory elastomers,a class of smart polymers,can remember their initial shapes under external stimuli and have potential applications in many fields,including medical devices,artificial muscles,actuators,and soft...Shape memory elastomers,a class of smart polymers,can remember their initial shapes under external stimuli and have potential applications in many fields,including medical devices,artificial muscles,actuators,and soft robots.Therefore,this review aims to explore research progress on the molecular structures,stimuli-responsive mechanisms,and emerging applications of shape memory elastomers and their composites in recent years.First,the molecular structures,shape memory effects,and working mechanisms of shape memory elastomers are thoroughly discussed and explained based on different external stimuli,including heat,light,electricity,magnetic fields,and solvents.Subsequently,emerging applications of shape memory elastomers,such as artificial muscles,actuators,soft robots,smart electronics,and aerospace,are presented.Finally,future challenges and insights into shape memory elastomers are discussed.Shape memory elastomers have received extensive attention and show great application potential in many emerging fields.展开更多
Stimulus-responsive actuators are novel functional devices capable of sensing external stimuli and ex-hibiting specific deformation responses.MXene,owing to its unique 2D structure and efficient energy conversion effi...Stimulus-responsive actuators are novel functional devices capable of sensing external stimuli and ex-hibiting specific deformation responses.MXene,owing to its unique 2D structure and efficient energy conversion efficiency,has bridged the gap in traditional devices and shown great potential for multiple stimulus-responsive actuators.However,the drawbacks of pure MXene films,including susceptibility to oxidation and vulnerability to shear stress,hinder their applications.Through composite modification and structural design strategies,a three-layer structured MXene-carbon nanotubes hybrid film(tHCM)is fabri-cated,exhibiting a tensile strength and fracture strain of 153.8 MPa and 4.65%,respectively,representing improvements of 598.4%and 226.8%compared to the initial film.Meanwhile,the film maintains excel-lent stability demonstrating the enhancing effects of hydrogen bonds and densely packed structure.The hybrid films demonstrate unique and facile welding features due to splicing properties,enabling the for-mation of complex configurations.In terms of electro-/photo-thermal conversion performance,the hybrid film can reach a reasonably high temperature of 250℃at low voltage(2.5 V)and 110.6℃under 150 mW cm^(-2) infrared light.Leveraging the thermal expansion mismatch between tHCM and thermoplastic films,an integrated,flexible,and weldable actuator with unique electro/photo-response is developed,and vari-ous biomimetic driving applications,particularly,the light-mediated hierarchical transmission and precise motion along predetermined trajectory are realized.This work not only provides an effective strategy for modifying MXene composite films but also advances the design of novel actuators,offering broad appli-cation prospects in fields such as stimulus-responsive actuated robots and cargo transportation.展开更多
The objective of this paper is to incorporate vehicle mix in stimulus-response car-following models. Separate models were estimated for acceleration and deceleration responses to account for vehicle mix via both movem...The objective of this paper is to incorporate vehicle mix in stimulus-response car-following models. Separate models were estimated for acceleration and deceleration responses to account for vehicle mix via both movement state and vehicle type. For each model, three submodels were developed for different pairs of following vehicles including ＂automobile following automobile,＂ ＂automobile following truck,＂ and ＂truck following automobile.＂ The estimated model parameters were then validated against other data from a similar region and roadway. The results indicated that drivers＇ behaviors were significantly different among the different pairs of following vehicles. Also the magnitude of the estimated parameters depends on the type of vehicle being driven and/or followed. These results demonstrated the need to use separate models depending on movement state and vehicle type. The differences in parameter estimates confirmed in this paper highlight traffic safety and operational issues of mixed traffic operation on a single lane. The findings of this paper can assist transportation professionals to improve traffic simulation models used to evaluate the impact of different strategies on ameliorate safety and performance of highways. In addition, driver response time lag estimates can be used in roadway design to calculate important design parameters such as stopping sight distance on horizontal and vertical curves for both automobiles and trucks.展开更多
Increasing understanding of the pathogenesis of rheumatoid arthritis(RA)has remarkably promoted the development of effective therapeutic regimens of RA.Nevertheless,the inadequate response to current therapies in a pr...Increasing understanding of the pathogenesis of rheumatoid arthritis(RA)has remarkably promoted the development of effective therapeutic regimens of RA.Nevertheless,the inadequate response to current therapies in a proportion of patients,the systemic toxicity accompanied by longterm administration or distribution in non-targeted sites and the comprised efficacy caused by undesirable bioavailability,are still unsettled problems lying across the full remission of RA.So far,these existing limitations have inspired comprehensive academic researches on nanomedicines for RA treatment.A variety of versatile nanocarriers with controllable physicochemical properties,tailorable drug release pattern or active targeting ability were fabricated to enhance the drug delivery efficiency in RA treatment.This review aims to provide an up-to-date progress regarding to RA treatment using nanomedicines in the last 5 years and concisely discuss the potential application of several newly emerged therapeutic strategies such as inducing the antigen-specific tolerance,pro-resolving therapy or regulating the immunometabolism for RA treatments.展开更多
Stealth coating materials effectively extend a nanoparticle＇s systemic circulation lifetime yet limit its cellular internalization, which promotes and prevents tumor targeting, respectively. Here, this contradiction ...Stealth coating materials effectively extend a nanoparticle＇s systemic circulation lifetime yet limit its cellular internalization, which promotes and prevents tumor targeting, respectively. Here, this contradiction was resolved by using an acutely pH-sensitive zwitterionic stealth ligand capable of responding to small differences in extracellular pH between blood and tumors. Using a photothermal gold nanocage （AuNC） as a model nanotherapeutic, we found that stealth-AuNC nanoparticles showed both significantly enhanced cell uptake efficiency in acidic tumors and a markedly extended systemic circulation lifetime compared to its unaltered analogue. As a result, stealth-AuNC nanoparticles administered intravenously showed significantly enhanced accumulation within the tumor, leading to significantly improved photothermal therapeutic efficacy in mouse models. These results suggests that pH-sensitive zwitterionic ligands with sufficient sensitivity for responding to small differences in extracellular pH between blood and tumors are ideal stealth materials for simultaneously conferring both extended systemic circulation and enhanced cellular internalization, reducing the need for active targeting moieties.展开更多
基金supported by National Natural Science Foundation of China(No.52203016)China Postdoctoral Science Foundation(Nos.2021M703072 and 2022T150617)+1 种基金USTC Research Funds of the Double First-Class Initiative(No.YD9990002018)The Fundamental Research Funds for the Central Universities(No.WK9990000142)。
文摘The external stimulus response strategy has been evolved rapidly in the field of olefin polymerization.In this work,we modularly synthesized three types of double stimulus responsiveα-diimine palladium catalysts,combining redox regulation and other regulation together,such as light,Lewis acid and alkali cations.The catalytic activities and the molecular weight of polyethylene products can be regulated for 4 times in ethylene polymerization.These palladium complexes were also used for the copolymerization reaction of ethylene and polar monomers,such as methyl 10-undecylenate and methyl acrylate,effectively regulating the catalytic activities,the molecular weight and polar monomer incorporation of the prepared copolymers.The research on these dual-regulated palladium complexes makes full use of prepared catalysts and provides new inspirations for regulating olefin polymerization.
基金financially supported by the Research Impact Fund (project no. R4015-21)Research Fellow Scheme (project no. RFS2122-4S03)+3 种基金Strategic Topics Grant (project no. STG1/E-401/23- N) from the Hong Kong Research Grants Council (RGC)the CUHK internal grantsthe support from Multi-Scale Medical Robotics Centre (MRC),InnoHK, at the Hong Kong Science Parkthe SIAT–CUHK Joint Laboratory of Robotics and Intelligent Systems
文摘Miniature devices comprising stimulus-responsive hydrogels with high environmental adaptability are now considered competitive candidates in the fields of biomedicine,precise sensors,and tunable optics.Reliable and advanced fabricationmethods are critical formaximizing the application capabilities ofminiature devices.Light-based three-dimensional(3D)printing technology offers the advantages of a wide range of applicable materials,high processing accuracy,and strong 3D fabrication capability,which is suitable for the development of miniature devices with various functions.This paper summarizes and highlights the recent advances in light-based 3D-printed miniaturized devices,with a focus on the latest breakthroughs in lightbased fabrication technologies,smart stimulus-responsive hydrogels,and tunable miniature devices for the fields of miniature cargo manipulation,targeted drug and cell delivery,active scaffolds,environmental sensing,and optical imaging.Finally,the challenges in the transition of tunable miniaturized devices from the laboratory to practical engineering applications are presented.Future opportunities that will promote the development of tunable microdevices are elaborated,contributing to their improved understanding of these miniature devices and further realizing their practical applications in various fields.
基金supported by the National Natural Science Foundation of China (Nos. 52122511, 52105492, and 62005262)the National Key Research and Development Program of China (No. 2021YFF0502700)+2 种基金the Students’ Innovation and Entrepreneurship Foundation of USTC (Nos. CY2022G32 and XY2022G02CY)the USTC Research Funds of the Double First-Class Initiative (No. YD2340002009)CAS Project for Young Scientists in Basic Research (No. YSBR-049)
文摘Diverse natural organisms possess stimulus-responsive structures to adapt to the surrounding environment.Inspired by nature,researchers have developed various smart stimulus-responsive structures with adjustable properties and functions to address the demands of ever-changing application environments that are becoming more intricate.Among many fabrication methods for stimulus-responsive structures,femtosecond laser direct writing(FsLDW)has received increasing attention because of its high precision,simplicity,true three-dimensional machining ability,and wide applicability to almost all materials.This paper systematically outlines state-of-the-art research on stimulus-responsive structures prepared by FsLDW.Based on the introduction of femtosecond laser-matter interaction and mainstream FsLDW-based manufacturing strategies,different stimulating factors that can trigger structural responses of prepared intelligent structures,such as magnetic field,light,temperature,pH,and humidity,are emphatically summarized.Various applications of functional structures with stimuli-responsive dynamic behaviors fabricated by FsLDW,as well as the present obstacles and forthcoming development opportunities,are discussed.
基金Supported by the China National Science and Technology Major Project(2017ZX05009-003,2016ZX05020-004,2016ZX05040-005)
文摘AM-AMPS-TAC polymers with different charge distribution are synthesized using acrylamide(AM),2-acrylamido-2-methylpropanesulfonate(AMPS)and 3-acrylamidopropyl trimethylammonium(TAC)at different feed ratios by polymerization in solution.The salt-responsive behavior,reasons leading to salt-responsiveness,and effects of polymers molecular structure on salt-responsiveness are studied by laboratory experiments to find out the adaptability of the polymers.Rheology test under stepwise shear mode shows that the AM-AMPS-TAC polymers have salt responsiveness,and the closer the feeds of AMPS and ATC,the more significant the salt responsiveness will be.Conformation change of polymers molecular chain under salt stimulus is studied by turbidity test and micro-morphology analysis,and the responsive mechanism is further investigated by intrinsic viscosity test and copolymer composition analysis.Results indicate that the salt-responsive behavior of AM-AMPS-TAC polymers derives from the"curled to expanded"transition of chain conformation under salt stimulus,and this transition is led by the screening effect of salt which weakens polymers intramolecular ionic bond.Application in saturated saltwater drilling fluid shows that the AM90-AMPS5-TAC5 polymer has the best salt-tolerance and temperature-tolerance when used together with fluid loss controller PAC-Lv.The drilling fluid saturated with NaCl can maintain stable viscosity,good dispersion and low fluid loss for long time under 150℃.
基金supported by the National Key Basic Research Program of China (Grant No 2005CB623903)the National Natural Science Foundation of China (Grant No 50633020)+1 种基金the Program for Young Excellent Talents in Tongji University,the Special Project of Shanghai Nanotechnology (Grant No 0952nm04800)Natural Science Foundation of Shanghai (Grant No 10ZR1432100)
文摘Polymeric nanoparticles with unique properties are regarded as the most promising materials for biomedical applications including drug delivery and in vitro/in vivo imaging.Among them,stimulus-responsive polymeric nanoparticles,usually termed as "intelligent" nanoparticles,could undergo structure,shape,and property changes after being exposed to external signals including pH,temperature,magnetic field,and light,which could be used to modulate the macroscopical behavior of the nanoparticles.This paper reviews the recent progress in stimulus-responsive nanoparticles used for drug delivery and in vitro/in vivo imaging,with an emphasis on double/multiple stimulus-responsive systems and their biomedical applications.
基金the starting Grants of Tianjin University,Grant/Award Number:001Natural Science Foundation of Tianjin City+3 种基金National Natural Science Foundation of ChinaTianjin Universitythe starting Grants of Tianjin University and Tianjin Government,National Natural Science Foundation of China(No.51903188)Natural Science Foundation of Tianjin City(No.19JCQNJC04500)for financial support.
文摘Luminogens that exhibit stimulus-responsive room temperature phosphorescence(RTP)have attracted significant attention for their applications in a wide range of fields such as data storage,sensors,and bio-imaging.However,very few such materials are known,partly because of the unclear internal mechanism.In this review,we summarize recent advances in the field of stimulusresponsive RTP in purely organic luminogens,focusing on their unique emission behaviors and internal mechanisms governing the phenomena.We also attempt to identify the relationship between the mechanism,luminogens,and possible applications.
基金financially supported by the National Key R&D Program of China(2017YFE0127600)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA22010600)+4 种基金the National Natural Science Foundation of China(21975271)the Key-Area Research and Development Program of Guangdong Province(2020B090919005)Shandong Natural Science Foundation(ZR2020ZD07 and ZR2021QB106)the financial support from the Youth Innovation Promotion Association of CAS(2019214)Shandong Energy Institute(SEI 1202127)。
文摘Stimulus-responsive energy storage devices,which can respond to external stimuli,such as heat,pH,moisture,pressure,or electric field,have recently attracted intensive attention,aiming at the ever-increasing demand for safe batteries and smart electronics.The most typical stimulus-responsive materials are polymers that can change their conformation by forming and destroying secondary forces,including hydrogen bonds and electrostatic interactions in response to external stimuli,accompanied by changes in the intrinsic properties such as conductivity and hydrophobicity.Although the applications of stimulus-responsive functions in rechargeable batteries are still in the early stage because of the complexity and compatibility of battery architectures,many new concepts of regulating the polymer structures upon applications of stimuli have already been developed.In this review,we discuss the recent progress of stimulus-responsive polymers on energy storage devices featuring thermal protection and intelligent scenarios,with a focus on the detailed structural transformations of polymers under a given stimulus and the corresponding changes in battery performance.Finally,we present perspectives on the current limitations and future research directions of stimulus-responsive polymers for energy storage devices.
基金National Natural Science Foundation of China,Grant/Award Numbers:52073017,51773009FundamentalResearch Funds for the Central Universities+1 种基金NationalNatural Science Foundation of China,Grant/Award Numbers:52073017,51773009FundamentalResearch Funds for the Central Universities。
文摘Circularly polarized luminescence(CPL)has gained considerable attention in various systems and has rapidly developed into an emerging research field.To meet the needs of actual applications in diverse fields,a high luminescence dissymmetry factor(glum)and tunable optical performance of CPL would be the most urgent pursuit for researchers.Accordingly,many emerging CPL materials and various strategies have been developed to address these critical issues.Emissive cholesteric liquid crystals(CLCs),that is,luminescent self-organized helical superstructures,are considered to be ideal candidates for constructing CPL-active materials,as they not only exhibit high glum values,but also enable flexible optical control of CPL.This review mainly summarizes the characteristics of CPL based on CLCs as the bulk phase doped with different emitters,including aggregated induced emission molecules,conventional organic small molecules,polymer emitters,metal-organic complex emitters,and luminescent nanoparticles.In addition,the recent significant progress in stimulus-responsive CPL based on emissive CLCs in terms of several types of stimuli,including light,electricity,temperature,mechanical force,and multiple stimuli is presented.Finally,a short perspective on the opportunities and challenges associated with CPL-active materials based on the CLC field is provided.This review is anticipated to offer new insights and guidelines for developing CLC-based CPL-active materials for broader applications.
基金supported by National Natural Science Foundation of China(Nos.52103190 and 52103191)Special Program for Supporting Innovative Youth Talent Teams(No.32320683)+1 种基金Start-up Grant(Nos.32340311 and 35220151) from Zhengzhou UniversityNatural Science Foundation of Henan Province(No.242300420127)。
文摘Nanomaterials that can sequentially respond to internal and external stimuli,functioning as a sequential gate,have great potential for targeting different aspects of antitumor immunity.Herein,we construct a mannose-modified,pH and reactive oxygen species(ROS) sequential-responsive,transformable dualimmunofunction nanoprodrug(MpRTNP).This nanoprodrug encapsulates a transforming growth factor-β(TGF-β) receptor inhibitor SD-208(MpRTNP@SD),to simultaneously alleviate the immunosuppressive effects of TGF-β and tumor-associated macrophages(TAMs).In the weakly acidic tumor microenvironment(TME),the vesicle-micelle morphology transformation occurs owing to the protonation of PC7A,which is accompanied by SD-208 release to inhibit cancer-associated fibroblasts and regulatory T cells.The transformed micelles then target TAMs via mannose receptor-media ted endocytosis.Upon laser irradiation,the thioketal linker is cleaved,releasing conjugated chlorin e6 and generating ROS,which facilitates TAM polarization.The PC7A^(+) segment activates the stimulator of the interferon gene in TAMs with elevated phosphorylation of TANK binding kinase 1 and interferon regulatory factor 3,and type I interferon secretion.MpRTNP@SD displays superior abscopal effects and robust antitumor immunity,as evidenced by increased CD8^(+)/CD4^(+) T cell infiltration and reduced regulatory T cell(Treg) ratios.Mouse survival time is prolonged after combination with the CD47 antibody.This study provides a novel strategy for potent antitumor immunotherapy through pH and ROS sequential-gated spatiotemporal regulation of the TME.
基金supported by the Postdoctoral Fellowship Program of CPSF(No.GZB-20230714)the China Postdoctoral Science Foundation funded project(No.2023M743387).
文摘Stimulus-responsive liquid foams have gained much attention for use in various industrial applications.However,it remains challenging to construct such systems with integrated functionality of easy preparation,high stability,high foaming ability,and rapid on-demand degradation.Herein,by combining the Hofmeister effect and nanotechnology,a promising ultrastable and photoresponsive liquid foam was prepared that had a lifetime of several months and could be destroyed on demand in a few minutes.Specifically,the system was prepared by simply mixing a gelatine solution containing black phosphorus nanosheets(BPNs)and kosmotropic anions in the Hofmeister series with air in one step using only two syringes,and there were no chemical modifications or crosslinking agents required.The kosmotropic anions induced stronger hydrophobic interactions,bundling within molecular chains,and blockage of foam drainage channels,which significantly improved the foaming ability and the lifetime and mechanical properties of the foam.Moreover,rational structure design realized a promising on-demand degradation mechanism via a cascading“light trigger-heat generation-Marangoni flow generation”process occurring on the bubble surfaces.On this basis,the BPNs converted light into thermal energy,which induced Marangoni flow driven by surface tension gradients along the gas-liquid interfaces,and the bubble film ruptured within seconds upon light illumination.The designed stimulus-response systems combined stable,fast and repeatable processes without sacrificing the foaming abilities,thus providing a general way to control the stabilities of foams,bubbles and films.
基金financial support from the National Natural Science Foundation of China(No.22275148)National Key R&D Program of China(No.2018YFB1900201)for Qiuyu Zhang+2 种基金the National Natural Science Foundation of China(No.22271232)Fundamental Research Funds for the Central Universities(No.D5000230114)for Shixin Fathe Fundamental Research Funds for the Central Universities(No.D5000220339)for Qing Liu。
文摘This work develops a protein imprinted nanosphere with varied recognition specificity for bovine serum albumin(BSA)and lysozyme(Lyz)under different UV light through a gradient dual crosslinked imprinting strategy(i.e.,covalent crosslinking and dynamic reversible crosslinking).The imprinting cavities are initially constructed using irreversible covalent crosslinking to specifically recognize BSA,and then the coumarin residues in the imprinting cavities are crosslinked under 365 nm UV light to further imprint Lyz,because Lyz has smaller size than BSA.Since the photo-crosslinking of coumarin is a reversible reaction,the imprinting cavities of Lyz can be de-crosslinked under 254 nm UV light and restore the imprinting cavities of BSA.Moreover,the N-isopropyl acrylamide(NIPAM)and pyrrolidine residues copolymerized in the polymeric surface of the nanospheres are temperature-and p H-responsive respectively.Therefore,the protein rebinding and release behaviors of the nanospheres are controlled by external temperature and p H.As a result,the materials can selectively separate BSA from real bovine whole blood and Lyz from egg white under different UV light.This study may provide a new strategy for construction of protein imprinted materials with tunable specificity for different proteins.
文摘Shot and step response measurements were carried out with inert bed and adsorption bed both under iso-thermal conditions.Parameter values were determined from a time domain analysis of the measured inputand response signal.Sensitivity test in the parameter values showed that shot response measurements maygive more reliable parameter values than step measurements.Since Kubin[1]and Kucera[2]proposed a parameter estimation technique based on a moment methodfor adsorption system,attention has been focused on dynamic input-output measurements with variouspacked bed systems for the parameter estimation.The object of this work is to compare shot and step re-sponse measurements and see which measurement gives more reliable parameter values.
基金supported by the Beijing Natural Science Foundation(No.L222128)Beijing Institute of Technology Research Fund Program for Young Scholars(No.XSQD-202121010)National Natural Science Foundation of China(No.81961138009)。
文摘Insufficient intratumoral retention of nanomedicines remains the major challenge for broad implementation in clinical sets.Herein,we proposed a legumain-triggered aggregable gold nanoparticle(GNP)delivery platform(GNPs-A&C).GNPs-A&C could form intratumoral or intracellular aggregates in response to the overexpressed legumain.The aggregates with size increase not only could reduce back-flow from interstitial space to peripheral bloodstream but also could restrict the cellular exocytosis,leading to enhanced intratumoral retention.In vitro studies demonstrated that GNPs-A&C possessed an excellent legumain responsiveness and the increased size was closely relevant with legumain expression.In vivo studies demonstrated GNPs-A&C possessed slower clearance rate and much higher intratumoral retention within legumain-overexpressed tumor compared to non-aggregable NPs,regardless of intravenous or intratumoral injection.More importantly,this delivery platform significantly improved the chemotherapeutic effect of doxorubicin(DOX)towards subcutaneous xenograft C6 tumor.The effectiveness of this stimulus-responsive aggregable delivery system provides a thinking for designing more intelligent size-tunable nanomedicine that can substantially improve intratumoral retention.
基金the financial support from the National Natural Science Foundation of China(No.22175033)Science and Technology Development Plan of Jilin Province(Nos.YDZJ202101ZYTS063,2021050822RQ)。
文摘Solid-state materials that exhibit pressure stimulus-response characteristics in a manner of emission signal,known as piezochromic luminescence(PCL),demonstrate great potential in photoelectric devices.The weakened luminescence and insignificant color change in the aggregation state,however,hampers their practical applications.Herein,a highly emissive coordination polymer,[Zn2(H4TTPE)(H2O)4]·H2O(CUST-805),is successfully constructed by employing an AIE-active chromophore as the building block.The structural characterization and photophysical properties are systematically studied.Owing to intrinsic twisted conformation and AIE feature of tetraphenylethylene-tetrazole ligand,CUST-805 achieves the visible and reversible PCL from blue to green switched by different external stimuli.The transformation between crystalline and amorphous states is proved to be the origin of present PCL behavior.Moreover,on basis of electron and energy transfer quenching mechanism,the highly selective and sensitive sensor based on CUST-805 is realized,showing the low detection limit of 0.29 ppm towards 2,4,6-trinitrophenol.
基金supported by the National Natural Science Foundation of China(Grant:52033011,52273104)Guangdong Basic and Applied Basic Research Foundation(Grant:2022A1515011972,2023A1515010694).
文摘Shape memory elastomers,a class of smart polymers,can remember their initial shapes under external stimuli and have potential applications in many fields,including medical devices,artificial muscles,actuators,and soft robots.Therefore,this review aims to explore research progress on the molecular structures,stimuli-responsive mechanisms,and emerging applications of shape memory elastomers and their composites in recent years.First,the molecular structures,shape memory effects,and working mechanisms of shape memory elastomers are thoroughly discussed and explained based on different external stimuli,including heat,light,electricity,magnetic fields,and solvents.Subsequently,emerging applications of shape memory elastomers,such as artificial muscles,actuators,soft robots,smart electronics,and aerospace,are presented.Finally,future challenges and insights into shape memory elastomers are discussed.Shape memory elastomers have received extensive attention and show great application potential in many emerging fields.
基金support provided by the National Natural Science Foundation of China(No.52002324)the Hong Kong Scholars Program(Nos.XJ2021073 and PolyU YZ4V)the Research Grants Council of Hong Kong GRF(No.15303123).
文摘Stimulus-responsive actuators are novel functional devices capable of sensing external stimuli and ex-hibiting specific deformation responses.MXene,owing to its unique 2D structure and efficient energy conversion efficiency,has bridged the gap in traditional devices and shown great potential for multiple stimulus-responsive actuators.However,the drawbacks of pure MXene films,including susceptibility to oxidation and vulnerability to shear stress,hinder their applications.Through composite modification and structural design strategies,a three-layer structured MXene-carbon nanotubes hybrid film(tHCM)is fabri-cated,exhibiting a tensile strength and fracture strain of 153.8 MPa and 4.65%,respectively,representing improvements of 598.4%and 226.8%compared to the initial film.Meanwhile,the film maintains excel-lent stability demonstrating the enhancing effects of hydrogen bonds and densely packed structure.The hybrid films demonstrate unique and facile welding features due to splicing properties,enabling the for-mation of complex configurations.In terms of electro-/photo-thermal conversion performance,the hybrid film can reach a reasonably high temperature of 250℃at low voltage(2.5 V)and 110.6℃under 150 mW cm^(-2) infrared light.Leveraging the thermal expansion mismatch between tHCM and thermoplastic films,an integrated,flexible,and weldable actuator with unique electro/photo-response is developed,and vari-ous biomimetic driving applications,particularly,the light-mediated hierarchical transmission and precise motion along predetermined trajectory are realized.This work not only provides an effective strategy for modifying MXene composite films but also advances the design of novel actuators,offering broad appli-cation prospects in fields such as stimulus-responsive actuated robots and cargo transportation.
文摘The objective of this paper is to incorporate vehicle mix in stimulus-response car-following models. Separate models were estimated for acceleration and deceleration responses to account for vehicle mix via both movement state and vehicle type. For each model, three submodels were developed for different pairs of following vehicles including ＂automobile following automobile,＂ ＂automobile following truck,＂ and ＂truck following automobile.＂ The estimated model parameters were then validated against other data from a similar region and roadway. The results indicated that drivers＇ behaviors were significantly different among the different pairs of following vehicles. Also the magnitude of the estimated parameters depends on the type of vehicle being driven and/or followed. These results demonstrated the need to use separate models depending on movement state and vehicle type. The differences in parameter estimates confirmed in this paper highlight traffic safety and operational issues of mixed traffic operation on a single lane. The findings of this paper can assist transportation professionals to improve traffic simulation models used to evaluate the impact of different strategies on ameliorate safety and performance of highways. In addition, driver response time lag estimates can be used in roadway design to calculate important design parameters such as stopping sight distance on horizontal and vertical curves for both automobiles and trucks.
基金supported by the National Natural Science Foundation of China(52173094 and 52003062)Guangxi Natural Science Foundation of China(2019GXNSFFA245010)the Scientific and Technological Plan of Guilin City(20220110-1).
基金supported by the National Natural Science Foundation of China(No.82003661)。
文摘Increasing understanding of the pathogenesis of rheumatoid arthritis(RA)has remarkably promoted the development of effective therapeutic regimens of RA.Nevertheless,the inadequate response to current therapies in a proportion of patients,the systemic toxicity accompanied by longterm administration or distribution in non-targeted sites and the comprised efficacy caused by undesirable bioavailability,are still unsettled problems lying across the full remission of RA.So far,these existing limitations have inspired comprehensive academic researches on nanomedicines for RA treatment.A variety of versatile nanocarriers with controllable physicochemical properties,tailorable drug release pattern or active targeting ability were fabricated to enhance the drug delivery efficiency in RA treatment.This review aims to provide an up-to-date progress regarding to RA treatment using nanomedicines in the last 5 years and concisely discuss the potential application of several newly emerged therapeutic strategies such as inducing the antigen-specific tolerance,pro-resolving therapy or regulating the immunometabolism for RA treatments.
文摘Stealth coating materials effectively extend a nanoparticle＇s systemic circulation lifetime yet limit its cellular internalization, which promotes and prevents tumor targeting, respectively. Here, this contradiction was resolved by using an acutely pH-sensitive zwitterionic stealth ligand capable of responding to small differences in extracellular pH between blood and tumors. Using a photothermal gold nanocage （AuNC） as a model nanotherapeutic, we found that stealth-AuNC nanoparticles showed both significantly enhanced cell uptake efficiency in acidic tumors and a markedly extended systemic circulation lifetime compared to its unaltered analogue. As a result, stealth-AuNC nanoparticles administered intravenously showed significantly enhanced accumulation within the tumor, leading to significantly improved photothermal therapeutic efficacy in mouse models. These results suggests that pH-sensitive zwitterionic ligands with sufficient sensitivity for responding to small differences in extracellular pH between blood and tumors are ideal stealth materials for simultaneously conferring both extended systemic circulation and enhanced cellular internalization, reducing the need for active targeting moieties.
