Classical-quantum correspondence has been an intriguing issue ever since quantum theory was proposed. The search- ing for signatures of classically nonintegrable dynamics in quantum systems comprises the interesting f...Classical-quantum correspondence has been an intriguing issue ever since quantum theory was proposed. The search- ing for signatures of classically nonintegrable dynamics in quantum systems comprises the interesting field of quantum chaos. In this short review, we shall go over recent efforts of extending the understanding of quantum chaos to relativistic cases. We shall focus on the level spacing statistics for two-dimensional massless Dirac billiards, i.e., particles confined in a closed region. We shall discuss the works for both the particle described by the massless Dirac equation （or Weyl equation） and the quasiparticle from graphene. Although the equations are the same, the boundary conditions are typically different, rendering distinct level spacing statistics.展开更多
Sparse identification of nonlinear dynamics(SINDy)has made significant progress in data-driven dynamics modeling.However,determining appropriate hyperparameters and addressing the time-consuming symbolic regression pr...Sparse identification of nonlinear dynamics(SINDy)has made significant progress in data-driven dynamics modeling.However,determining appropriate hyperparameters and addressing the time-consuming symbolic regression process remain substantial challenges.This study proposes the adaptive backward stepwise selection of fast SINDy(ABSS-FSINDy),which integrates statistical learning-based estimation and technical advancements to significantly reduce simulation time.This approach not only provides insights into the conditions under which SINDy performs optimally but also highlights potential failure points,particularly in the context of backward stepwise selection(BSS).By decoding predefined features into textual expressions,ABSS-FSINDy significantly reduces the simulation time compared with conventional symbolic regression methods.We validate the proposed method through a series of numerical experiments involving both planar/spatial dynamics and high-dimensional chaotic systems,including Lotka-Volterra,hyperchaotic Rossler,coupled Lorenz,and Lorenz 96 benchmark systems.The experimental results demonstrate that ABSS-FSINDy autonomously determines optimal hyperparameters within the SINDy framework,overcoming the curse of dimensionality in high-dimensional simulations.This improvement is substantial across both lowand high-dimensional systems,yielding efficiency gains of one to three orders of magnitude.For instance,in a 20D dynamical system,the simulation time is reduced from 107.63 s to just 0.093 s,resulting in a 3-order-of-magnitude improvement in simulation efficiency.This advancement broadens the applicability of SINDy for the identification and reconstruction of high-dimensional dynamical systems.展开更多
We have developed a simple one-step process for synthesis of ternary quantum dots(ZnCdSe,MgCdSe) with photoluminescence wavelengths ranging from the red to the blue region of the visible spectrum.The primary aim of th...We have developed a simple one-step process for synthesis of ternary quantum dots(ZnCdSe,MgCdSe) with photoluminescence wavelengths ranging from the red to the blue region of the visible spectrum.The primary aim of this work was to develop a synthesis for the preparation of Cd-containing quantum dots using a Cd precursor with lower toxicity than those used in common syntheses. This synthesis makes use of Cd(acac)_2 which is significantly less toxic than precursors such as CdO and CdCl_2. We have studied the effect of solvent boiling point, precursors and reaction time on the photoluminescence properties of the ternary quantum dots. Ternary quantum dots synthesized from Cd(acac)_2 in low boiling point solvents have photoluminescence wavelengths in the blue region, while those synthesized in high boiling point solvents have photoluminescence wavelengths in the red region.展开更多
Zwitterion-based materials by virtue of their special physical and chemical characteristics have attracted researchers to utilize them for fabricating functional coatings. The simultaneous presence of positive and neg...Zwitterion-based materials by virtue of their special physical and chemical characteristics have attracted researchers to utilize them for fabricating functional coatings. The simultaneous presence of positive and negative charges renders the zwitterion-based materials with electrostatically induced hydration properties, which enables a high resistance towards oily pollutants, nonspecific protein adsorption, bacterial adhesion and biofilm formation. This review starts from the working mechanism of zwitterions and covers the fabrication strategies of zwitterion-based functional coatings, namely the zwitterion-bearing binder route, the zwitterion-bearing additive route and the post-generation of coatings containing zwitterionic precursors. The applications of zwitterion-based functional coatings are discussed, including medical implants, marine antifouling and oil-resistant coatings, with focus on the relevant mechanisms of the zwitterion-containing coatings for a specific performance. Finally, some comments and perspectives on the current situation and future development of zwitterion-based functional coatings are given.展开更多
The key risk factor for glaucoma is increased intraocular pressure (IOP). Glaucoma drainage devices implanted in theeye can reduce IOP and thus stop disease progression. However, most devices currently used in clinica...The key risk factor for glaucoma is increased intraocular pressure (IOP). Glaucoma drainage devices implanted in theeye can reduce IOP and thus stop disease progression. However, most devices currently used in clinical practice arepassive and do not allow for postsurgical IOP control, which may result in serious complications such as hypotony (i.e.,excessively low IOP). To enable noninvasive IOP control, we demonstrate a novel, miniature glaucoma implant that willenable the repeated adjustment of the hydrodynamic resistance after implantation. This is achieved by integrating amagnetic microvalve containing a micropencil-shaped plug that is moved using an external magnet, thereby openingor closing fluidic channels. The microplug is made from biocompatible poly(styrene-block-isobutylene-block-styrene)(SIBS) containing iron microparticles. The complete implant consists of an SIBS drainage tube and a housing elementcontaining the microvalve and fabricated with hot embossing using femtosecond laser-machined glass molds. Usingin vitro and ex vivo microfluidic experiments, we demonstrate that when the microvalve is closed, it can providesufficient hydrodynamic resistance to overcome hypotony. Valve function is repeatable and stable over time. Due to itssmall size, our implant is a promising, safe, easy-to-implant, minimally invasive glaucoma surgery device.展开更多
Periodontitis is a chronic inflammatory condition that often causes serious damage to tooth-supporting tissues.The limited successful outcomes of clinically available approaches underscore the need for therapeutics th...Periodontitis is a chronic inflammatory condition that often causes serious damage to tooth-supporting tissues.The limited successful outcomes of clinically available approaches underscore the need for therapeutics that cannot only provide structural guidance to cells but can also modulate the local immune response.Here,three-dimensional melt electrowritten(i.e.,poly(ε-caprolactone))scaffolds with tissue-specific attributes were engineered to guide differentiation of human-derived periodontal ligament stem cells(hPDLSCs)and mediate macrophage polarization.The investigated tissue-specific scaffold attributes comprised fiber morphology(aligned vs.random)and highly-ordered architectures with distinct strand spacings(small 250μm and large 500μm).Macrophages exhibited an elongated morphology in aligned and highly-ordered scaffolds,while maintaining their round-shape on randomly-oriented fibrous scaffolds.Expressions of periostin and IL-10 were more pronounced on the aligned and highly-ordered scaffolds.While hPDLSCs on the scaffolds with 500μm strand spacing show higher expression of osteogenic marker(Runx2)over 21 days,cells on randomly-oriented fibrous scaffolds showed upregulation of M1 markers.In an orthotopic mandibular fenestration defect model,findings revealed that the tissue-specific scaffolds(i.e.,aligned fibers for periodontal ligament and highly-ordered 500μm strand spacing fluorinated calcium phosphate[F/CaP]-coated fibers for bone)could enhance the mimicking of regeneration of natural periodontal tissues.展开更多
CONSPECTUS:Cells have evolved to be self-sustaining compartmentalized systems that consist of many thousands of biomolecules and metabolites interacting in complex cycles and reaction networks.Numerous subtle intricac...CONSPECTUS:Cells have evolved to be self-sustaining compartmentalized systems that consist of many thousands of biomolecules and metabolites interacting in complex cycles and reaction networks.Numerous subtle intricacies of these self-assembled structures are still largely unknown.The importance of liquid−liquid phase separation(both membraneless and mem-brane bound)is,however,recognized as playing an important role in achieving biological function that is controlled in time and space.Reconstituting biochemical reactions in vitro has been a success of the last decades,for example,establishment of the minimal set of enzymes and nutrients able to replicate cellular activities like the in vitro transcription translation of genes to proteins.Further than this though,artificial cell research has the aim of combining synthetic materials and nonliving macromolecules into ordered assemblies with the ability to carry out more complex and ambitious cell-like functions.These activities can provide insights into fundamental cell processes in simplified and idealized systems but could also have an applied impact in synthetic biology and biotechnology in the future.To date,strategies for the bottom-up fabrication of micrometer scale life-like artificial cells have included stabilized water-in-oil droplets,giant unilamellar vesicles(GUV’s),hydrogels,and complex coacervates.Water-in-oil droplets are a valuable and easy to produce model system for studying cell-like processes;however,the lack of a crowded interior can limit these artificial cells in mimicking life more closely.Similarly membrane stabilized vesicles,such as GUV’s,have the additional membrane feature of cells but still lack a macromolecularly crowded cytoplasm.Hydrogel-based artificial cells have a macromolecularly dense interior(although cross-linked)that better mimics cells,in addition to mechanical properties more similar to the viscoelasticity seen in cells but could be seen as being not dynamic in nature and limiting to the diffusion of biomolecules.On the other hand,liquid−liquid phase separated complex coacervates are an ideal platform for artificial cells as they can most accurately mimic the crowded,viscous,highly charged nature of the eukaryotic cytoplasm.Other important key features that researchers in the field target include stabilizing semipermeable membranes,compartmentalization,information transfer/communication,motility,and metabolism/growth.In this Account,we will briefly cover aspects of coacervation theory and then outline key cases of synthetic coacervate materials used as artificial cells(ranging from polypeptides,modified polysaccharides,polyacrylates,and polymethacrylates,and allyl polymers),finishing with envisioned opportunities and potential applications for coacervate artificial cells moving forward.展开更多
The Hopf whole-brain model,based on structural connectivity,overcomes limitations of traditional structural or functional connectivity-focused methods by incorporating heterogeneity parameters,quantifying dynamic brai...The Hopf whole-brain model,based on structural connectivity,overcomes limitations of traditional structural or functional connectivity-focused methods by incorporating heterogeneity parameters,quantifying dynamic brain characteristics in healthy and diseased states.Traditional parameter fitting techniques lack precision,restricting broader use.To address this,we validated parameter fitting methods using simulated networks and synthetic models,introducing improvements such as individual-specific initialization and optimized gradient descent,which reduced individual data loss.We also developed an approximate loss function and gradient adjustment mechanism,enhancing parameter fitting accuracy and stability.Applying this refined method to datasets for major depressive disorder(MDD)and autism spectrum disorder(ASD),we identified differences in brain regions between patients and healthy controls,explaining related anomalies.This rigorous validation is crucial for clinical application,paving the way for precise neuropathological identification and novel treatments in neuropsychiatric research,demonstrating substantial potential in clinical neurology.展开更多
Optical neural networks(ONNs)are a class of emerging computing platforms that leverage the properties of light to perform ultra-fast computations with ultra-low energy consumption.ONNs often use CCD cameras as the out...Optical neural networks(ONNs)are a class of emerging computing platforms that leverage the properties of light to perform ultra-fast computations with ultra-low energy consumption.ONNs often use CCD cameras as the output layer.In this work,we propose the use of perovskite solar cells as a promising alternative to imaging cameras in ONN designs.Solar cells are ubiquitous,versatile,highly customizable,and can be fabricated quickly in laboratories.Their large acquisition area and outstanding efficiency enable them to generate output signals with a large dynamic range without the need for amplification.Here we have experimentally demonstrated the feasibility of using perovskite solar cells for capturing ONN output states,as well as the capability of single-layer random ONNs to achieve excellent performance even with a very limited number of pixels.Our results show that the solar-cell-based ONN setup consistently outperforms the same setup with CCD cameras of the same resolution.These findings highlight the potential of solar-cell-based ONNs as an ideal choice for automated and battery-free edge-computing applications.展开更多
Twisted bilayer photonic crystals introduce a twist between two stacked photonic crystal slabs,enabling strong modulation of their electromagnetic properties.The change in the twist angle strongly influences the reson...Twisted bilayer photonic crystals introduce a twist between two stacked photonic crystal slabs,enabling strong modulation of their electromagnetic properties.The change in the twist angle strongly influences the resonant frequencies and available propagating diffraction orders with applications including sensing,lasing,slow light or wavefront engineering.In this work,we design and analyze twisted bilayer crystals capable of steering light in a direction controlled by the twist angle.To achieve beam steering,the device efficiently routes input power into a single,twist-dependent,transmitted diffraction order.The outgoing light then follows the orientation of this diffraction order,externally controlled by the twist angle.Our study shows,using systematic exploration of the design space,how the device resembles blazed gratings by effectively canceling the undesired diffraction orders.The optimized devices exhibit a shared slant dependent on the selected diffraction order and that proves robust to the twist angle.Our analysis is supported by a classical blazing model and a data-oriented statistical analysis.The data-oriented approach is steered by high-efficiency heuristic optimization method,which enabled the design of optimized devices demonstrating an efficiency above 90%across twist angles ranging from 0 to 30°for both TE and TM polarizations.Extending the optimization to include left-and right-handed polarizations yields overall accuracy nearing 90%when averaged across the entire 0 to 60°control range.Finally,with the identification of the blazing effect in this initially black box structure,we show one can consider simpler design for a first prototype.展开更多
During wound healing,fibroblasts undergo radical processes that impact their phenotype and behavior.They are activated,recruited to the injury site,assume a contractile phenotype,and secrete extracellular matrix prote...During wound healing,fibroblasts undergo radical processes that impact their phenotype and behavior.They are activated,recruited to the injury site,assume a contractile phenotype,and secrete extracellular matrix proteins to orchestrate tissue repair.Thus,fibroblast responses require dynamic changes in cytoskeleton assembly and organization,adhesion morphology,and force generation.At the same time,fibroblasts experience changes in environmental stiffness during tissue wounding and healing.Although cells are generally known to use their adhesioncontraction machinery to sense microenvironmental stiffness,little is known about how stiffness affects the fibroblast phenotypical transition and behavior in wound healing.Here we demonstrate that stiffness plays a deterministic role in determining fibroblast phenotype,surprisingly even overruling the classical TGF-β-mediated stimulation.By combining morphometric analysis,traction force microscopy,and single-cell migration analysis,we show that environmental stiffness primes the cytoskeletal and mechanical responses of fibroblasts,strongly modulating their morphology,force generation,and migration behavior.Our study,therefore,points to the importance of tissue stiffness as a key mechanobiological regulator of fibroblast behavior,thus serving as a potential target for controlling tissue repair.展开更多
Understanding cell-material interactions is crucial for advancing biomedical applications,influencing cellular behavior and medical device performance.Material properties can be manipulated to direct cell responses,be...Understanding cell-material interactions is crucial for advancing biomedical applications,influencing cellular behavior and medical device performance.Material properties can be manipulated to direct cell responses,benefiting applications from regenerative medicine to implantable devices such as silicone breast implants.Knowledge about the interaction differences between healthy and cancer cells with implants may guide implant design to more precisely influence cell adhesion and proliferation of healthy cells while inhibiting cancer cells,tailoring outcomes to specific cellular responses.To show-case this potential,breast epithelial cells and breast cancer cells were investigated regarding their interaction with a broad range of combined physicochemical properties.This study employed a silicone-based high-throughput screening method utilizing Double Orthogonal Gradients(DOGs)to investigate the influence of topography,stiffness,and wettability on breast epithelial cells(MCF10a)and breast cancer cells(MCF7).Results show distinct cellular responses,including decreased prolif-eration rates in both MCF10a and MCF7 cells with the introduction of surface topography and the dominant influence of wettability on cell adhesion,proliferation,and cluster formation.The screening identified specific regions of interest(ROIs)where MCF10a cell proliferation outperformed MCF7 cells and that topography inhibits cluster formation(tumorigenesis),offering potential prospects for the creation of novel implant surfaces.展开更多
Animals can modify their body shape and/or color for protection,camouflage and communication.This adaptability has inspired fabrication of actuators with structural color changes to endow soft robots with additional f...Animals can modify their body shape and/or color for protection,camouflage and communication.This adaptability has inspired fabrication of actuators with structural color changes to endow soft robots with additional functionalities.Using liquid crystal-based materials for actuators with structural color changes is a promising approach.In this review,we discuss the current state of liquid crystal-based actuators with structural color changes and the potential applications of these structural color actuators in soft robotic devices.展开更多
Nature has unparalleled control over the conforma-tion and dynamics of its folded macromolecular structures.Nature’s ability to arrange amino acids into a precise spatial organization by way of folding allows protein...Nature has unparalleled control over the conforma-tion and dynamics of its folded macromolecular structures.Nature’s ability to arrange amino acids into a precise spatial organization by way of folding allows proteins to fulfill specific functions in an ex-tremely efficient manner.展开更多
Aggregation-induced emission(AIE)is a phenomenon in which fluorescence is enhanced rather than quenched upon molecular assembly.AIE fluorogens(AIEgens)are flexible,conjugated systems that are limited in their dynamics...Aggregation-induced emission(AIE)is a phenomenon in which fluorescence is enhanced rather than quenched upon molecular assembly.AIE fluorogens(AIEgens)are flexible,conjugated systems that are limited in their dynamics when assembled,which improves their fluorescent properties.This intriguing feature has been incorporated in many different molecular assemblies and has been extended to nanoparticles composed of amphiphilic polymer building blocks.The integration of the fascinating AIE design principle with versatile polymer chemistry opens up new frontiers to approach and solve intrinsic obstacles of conventional fluorescent materials in nanoscience,including the aggregation-caused quenching effect.Furthermore,this integration has drawn significant attention from the nanomedicine community,due to the additional advantages of nanoparticles comprising AIEgenic molecules,such as emission brightness and fluorescence stability.In this regard,a range of AIEgenic amphiphilic polymers have been developed,displaying enhanced emission in the self-assembly/aggregated state.AIEgenic assemblies are regarded as attractive nanomaterials with inherent fluorescence,which display promising features in a biomedical context,for instance in biosensing,cell/tissue imaging and tracking,as well as(photo)therapeutics.In this review,we describe recent strategies for the design and synthesis of novel types of AIEgenic amphiphilic polymers via facile approaches including direct conjugation to natural/synthetic polymers,polymerization,post-polymerization and supramolecular host−vip interactions.Their self-assembly behavior and biomedical potential will be discussed.展开更多
To expand the single-dose duration over which noninvasive clinical and preclinical cancer imaging can be conducted with high sensitivity,and well-defined spatial and temporal resolutions,a facile strategy to prepare u...To expand the single-dose duration over which noninvasive clinical and preclinical cancer imaging can be conducted with high sensitivity,and well-defined spatial and temporal resolutions,a facile strategy to prepare ultrasmall nanoparticulate X-ray contrast media(nano-XRCM)as dual-modality imaging agents for positron emission tomography(PET)and computed tomography(CT)has been established.Synthesized from controlled copolymerization of triiodobenzoyl ethyl acrylate and oligo(ethylene oxide)acrylate monomers,the amphiphilic statistical iodocopolymers(ICPs)could directly dissolve in water to afford thermodynamically stable solutions with high aqueous iodine concentrations(>140 mg iodine/mL water)and comparable viscosities to conventional small molecule XRCM.The formation of ultrasmall iodinated nanoparticles with hydrodynamic diameters of ca.10 nm in water was confirmed by dynamic and static light scattering techniques.In a breast cancer mouse model,in vivo biodistribution studies revealed that the64Cu-chelator-functionalized iodinated nano-XRCM exhibited extended blood residency and higher tumor accumulation compared to typical small molecule imaging agents.PET/CT imaging of tumor over 3 days showed good correlation between PET and CT signals,while CT imaging allowed continuous observation of tumor retention even after 10 days post-injection,enabling longitudinal monitoring of tumor retention for imaging or potentially therapeutic effect after a single administration of nano-XRCM.展开更多
Tissue-engineered constructs are promising to overcome shortage of organ donors and to reconstruct at least partsof injured or diseased tissues or organs. However, oxygen and nutrient supply are limiting factors in ma...Tissue-engineered constructs are promising to overcome shortage of organ donors and to reconstruct at least partsof injured or diseased tissues or organs. However, oxygen and nutrient supply are limiting factors in many tissues,especially after implantation into the host. Therefore, the development of a vascular system prior to implantationappears crucial. To develop a functional vascular system, different cell types that interact with each other need tobe co-cultured to simulate a physiological environment in vitro. This review provides an overview and a comparison ofthe current knowledge of co-cultures of human endothelial cells (ECs) with human adipose tissue-derived stem/stromal cells (ASCs) or bone marrow-mesenchymal stem cells (BMSCs) in three dimensional (3D) hydrogel matrices.Mesenchymal stem cells (MSCs), BMSCs or ASCs, have been shown to enhance vascular tube formation of ECs and toprovide a stabilizing function in addition to growth factor delivery and permeability control for ECs. Althoughphenotypically similar, MSCs from different tissues promote tubulogenesis through distinct mechanisms. In this report,we describe differences and similarities regarding molecular interactions in order to investigate which of these two celltypes displays more favorable characteristics to be used in clinical applications. Our comparative study shows that ASCsas well as BMSCs are both promising cell types to induce vascularization with ECs in vitro and consequently arepromising candidates to support in vivo vascularization.展开更多
The amplification of asymmetry from the molecular level to the macroscopic scale is an intriguing mechanism operative in natural systems to control complex functions.Inspired by nature,strategies for transferring chir...The amplification of asymmetry from the molecular level to the macroscopic scale is an intriguing mechanism operative in natural systems to control complex functions.Inspired by nature,strategies for transferring chiral information across length scales in purely synthetic systems have been investigated.[1,2]Thereof,chiral molecules are embedded into well-defined ordered supramolecular structures with the dynamics of noncovalent interactions leading to the amplification effect.展开更多
The investigation of the interplay between geometry and nonlinearity may open the road to the control of extreme waves. We study three-dimensional localization and dispersive shocks in a bent cigar shaped potential by...The investigation of the interplay between geometry and nonlinearity may open the road to the control of extreme waves. We study three-dimensional localization and dispersive shocks in a bent cigar shaped potential by the nonlinear Schro¨ dinger equation. At high bending and high nonlinearity, topological trapping is frustrated by the generation of curved wave-breaking. Four-dimensional parallel simulations confirm the theoretical model. This work may contribute to novel devices based on geometrically constrained highly nonlinear dynamics and tests and analogs of fundamental physical theories in curved space.展开更多
Modern machine-learning applications require huge artificial networks demanding computational power and memory.Light-based platforms promise ultrafast and energy-efficient hardware,which may help realize nextgeneratio...Modern machine-learning applications require huge artificial networks demanding computational power and memory.Light-based platforms promise ultrafast and energy-efficient hardware,which may help realize nextgeneration data processing devices.However,current photonic networks are limited by the number of inputoutput nodes that can be processed in a single shot.This restricted network capacity prevents their application to relevant large-scale problems such as natural language processing.Here,we realize a photonic processor for supervised learning with a capacity exceeding 1.5×10^(10)optical nodes,more than one order of magnitude larger than any previous implementation,which enables photonic large-scale text encoding and classification.By exploiting the full three-dimensional structure of the optical field propagating in free space,we overcome the interpolation threshold and reach the over-parameterized region of machine learning,a condition that allows high-performance sentiment analysis with a minimal fraction of training points.Our results provide a novel solution to scale up light-driven computing and open the route to photonic natural language processing.展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos. 11005053,11135001,and 11375074)the Air Force Office of Scientific Research (Grant No. FA9550-12-1-0095)the Office of Naval Research (Grant No. N00014-08-1-0627)
文摘Classical-quantum correspondence has been an intriguing issue ever since quantum theory was proposed. The search- ing for signatures of classically nonintegrable dynamics in quantum systems comprises the interesting field of quantum chaos. In this short review, we shall go over recent efforts of extending the understanding of quantum chaos to relativistic cases. We shall focus on the level spacing statistics for two-dimensional massless Dirac billiards, i.e., particles confined in a closed region. We shall discuss the works for both the particle described by the massless Dirac equation （or Weyl equation） and the quasiparticle from graphene. Although the equations are the same, the boundary conditions are typically different, rendering distinct level spacing statistics.
基金Project supported by the National Natural Science Foundation of China(Nos.12172291,12472357,and 12232015)the Shaanxi Province Outstanding Youth Fund Project(No.2024JC-JCQN-05)the 111 Project(No.BP0719007)。
文摘Sparse identification of nonlinear dynamics(SINDy)has made significant progress in data-driven dynamics modeling.However,determining appropriate hyperparameters and addressing the time-consuming symbolic regression process remain substantial challenges.This study proposes the adaptive backward stepwise selection of fast SINDy(ABSS-FSINDy),which integrates statistical learning-based estimation and technical advancements to significantly reduce simulation time.This approach not only provides insights into the conditions under which SINDy performs optimally but also highlights potential failure points,particularly in the context of backward stepwise selection(BSS).By decoding predefined features into textual expressions,ABSS-FSINDy significantly reduces the simulation time compared with conventional symbolic regression methods.We validate the proposed method through a series of numerical experiments involving both planar/spatial dynamics and high-dimensional chaotic systems,including Lotka-Volterra,hyperchaotic Rossler,coupled Lorenz,and Lorenz 96 benchmark systems.The experimental results demonstrate that ABSS-FSINDy autonomously determines optimal hyperparameters within the SINDy framework,overcoming the curse of dimensionality in high-dimensional simulations.This improvement is substantial across both lowand high-dimensional systems,yielding efficiency gains of one to three orders of magnitude.For instance,in a 20D dynamical system,the simulation time is reduced from 107.63 s to just 0.093 s,resulting in a 3-order-of-magnitude improvement in simulation efficiency.This advancement broadens the applicability of SINDy for the identification and reconstruction of high-dimensional dynamical systems.
基金CIT (Carnegie Institute of Technology)ICES (Institute of Complex Engineered System) for the financial support of this work
文摘We have developed a simple one-step process for synthesis of ternary quantum dots(ZnCdSe,MgCdSe) with photoluminescence wavelengths ranging from the red to the blue region of the visible spectrum.The primary aim of this work was to develop a synthesis for the preparation of Cd-containing quantum dots using a Cd precursor with lower toxicity than those used in common syntheses. This synthesis makes use of Cd(acac)_2 which is significantly less toxic than precursors such as CdO and CdCl_2. We have studied the effect of solvent boiling point, precursors and reaction time on the photoluminescence properties of the ternary quantum dots. Ternary quantum dots synthesized from Cd(acac)_2 in low boiling point solvents have photoluminescence wavelengths in the blue region, while those synthesized in high boiling point solvents have photoluminescence wavelengths in the red region.
基金Sponsored by the National Key Research and Development Program of China(Grant No.2020YFE0100300)the National Natural Science Foundation of China(Grant No.51973036)。
文摘Zwitterion-based materials by virtue of their special physical and chemical characteristics have attracted researchers to utilize them for fabricating functional coatings. The simultaneous presence of positive and negative charges renders the zwitterion-based materials with electrostatically induced hydration properties, which enables a high resistance towards oily pollutants, nonspecific protein adsorption, bacterial adhesion and biofilm formation. This review starts from the working mechanism of zwitterions and covers the fabrication strategies of zwitterion-based functional coatings, namely the zwitterion-bearing binder route, the zwitterion-bearing additive route and the post-generation of coatings containing zwitterionic precursors. The applications of zwitterion-based functional coatings are discussed, including medical implants, marine antifouling and oil-resistant coatings, with focus on the relevant mechanisms of the zwitterion-containing coatings for a specific performance. Finally, some comments and perspectives on the current situation and future development of zwitterion-based functional coatings are given.
基金This research was financially supported by the Chemelot Institute for Science&Technology(InSciTe)under grant agreement BM3.03 SEAMS。
文摘The key risk factor for glaucoma is increased intraocular pressure (IOP). Glaucoma drainage devices implanted in theeye can reduce IOP and thus stop disease progression. However, most devices currently used in clinical practice arepassive and do not allow for postsurgical IOP control, which may result in serious complications such as hypotony (i.e.,excessively low IOP). To enable noninvasive IOP control, we demonstrate a novel, miniature glaucoma implant that willenable the repeated adjustment of the hydrodynamic resistance after implantation. This is achieved by integrating amagnetic microvalve containing a micropencil-shaped plug that is moved using an external magnet, thereby openingor closing fluidic channels. The microplug is made from biocompatible poly(styrene-block-isobutylene-block-styrene)(SIBS) containing iron microparticles. The complete implant consists of an SIBS drainage tube and a housing elementcontaining the microvalve and fabricated with hot embossing using femtosecond laser-machined glass molds. Usingin vitro and ex vivo microfluidic experiments, we demonstrate that when the microvalve is closed, it can providesufficient hydrodynamic resistance to overcome hypotony. Valve function is repeatable and stable over time. Due to itssmall size, our implant is a promising, safe, easy-to-implant, minimally invasive glaucoma surgery device.
基金the National Institutes of Health(NIH-National Institute of Dental and Craniofacial Research,grants K08DE023552,R01DE026578)。
文摘Periodontitis is a chronic inflammatory condition that often causes serious damage to tooth-supporting tissues.The limited successful outcomes of clinically available approaches underscore the need for therapeutics that cannot only provide structural guidance to cells but can also modulate the local immune response.Here,three-dimensional melt electrowritten(i.e.,poly(ε-caprolactone))scaffolds with tissue-specific attributes were engineered to guide differentiation of human-derived periodontal ligament stem cells(hPDLSCs)and mediate macrophage polarization.The investigated tissue-specific scaffold attributes comprised fiber morphology(aligned vs.random)and highly-ordered architectures with distinct strand spacings(small 250μm and large 500μm).Macrophages exhibited an elongated morphology in aligned and highly-ordered scaffolds,while maintaining their round-shape on randomly-oriented fibrous scaffolds.Expressions of periostin and IL-10 were more pronounced on the aligned and highly-ordered scaffolds.While hPDLSCs on the scaffolds with 500μm strand spacing show higher expression of osteogenic marker(Runx2)over 21 days,cells on randomly-oriented fibrous scaffolds showed upregulation of M1 markers.In an orthotopic mandibular fenestration defect model,findings revealed that the tissue-specific scaffolds(i.e.,aligned fibers for periodontal ligament and highly-ordered 500μm strand spacing fluorinated calcium phosphate[F/CaP]-coated fibers for bone)could enhance the mimicking of regeneration of natural periodontal tissues.
基金financial support from the Dutch Ministry of Education,Culture,and Science(Gravitation program IPM 024.005.020 and Spinoza premium SPI 71-259)the European Union’s Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreements No.101022398,and No.859416.
文摘CONSPECTUS:Cells have evolved to be self-sustaining compartmentalized systems that consist of many thousands of biomolecules and metabolites interacting in complex cycles and reaction networks.Numerous subtle intricacies of these self-assembled structures are still largely unknown.The importance of liquid−liquid phase separation(both membraneless and mem-brane bound)is,however,recognized as playing an important role in achieving biological function that is controlled in time and space.Reconstituting biochemical reactions in vitro has been a success of the last decades,for example,establishment of the minimal set of enzymes and nutrients able to replicate cellular activities like the in vitro transcription translation of genes to proteins.Further than this though,artificial cell research has the aim of combining synthetic materials and nonliving macromolecules into ordered assemblies with the ability to carry out more complex and ambitious cell-like functions.These activities can provide insights into fundamental cell processes in simplified and idealized systems but could also have an applied impact in synthetic biology and biotechnology in the future.To date,strategies for the bottom-up fabrication of micrometer scale life-like artificial cells have included stabilized water-in-oil droplets,giant unilamellar vesicles(GUV’s),hydrogels,and complex coacervates.Water-in-oil droplets are a valuable and easy to produce model system for studying cell-like processes;however,the lack of a crowded interior can limit these artificial cells in mimicking life more closely.Similarly membrane stabilized vesicles,such as GUV’s,have the additional membrane feature of cells but still lack a macromolecularly crowded cytoplasm.Hydrogel-based artificial cells have a macromolecularly dense interior(although cross-linked)that better mimics cells,in addition to mechanical properties more similar to the viscoelasticity seen in cells but could be seen as being not dynamic in nature and limiting to the diffusion of biomolecules.On the other hand,liquid−liquid phase separated complex coacervates are an ideal platform for artificial cells as they can most accurately mimic the crowded,viscous,highly charged nature of the eukaryotic cytoplasm.Other important key features that researchers in the field target include stabilizing semipermeable membranes,compartmentalization,information transfer/communication,motility,and metabolism/growth.In this Account,we will briefly cover aspects of coacervation theory and then outline key cases of synthetic coacervate materials used as artificial cells(ranging from polypeptides,modified polysaccharides,polyacrylates,and polymethacrylates,and allyl polymers),finishing with envisioned opportunities and potential applications for coacervate artificial cells moving forward.
基金supported by the National Natural Science Foundation for Young Scholars of China(grant number 12205229 to J.J.and Q.-Y.Z.)STI 2030-Major Projects(no.2021ZD0201300 to J.J.,Q.-Y.Z.and Z.-G.H.)+1 种基金STI 2030-Major Projects(no.2022ZD0208500 to C.-W.S.)Natural Science Basic Research Plan in Shaanxi Province of China(no.2022JQ-010 to C.-W.S.).
文摘The Hopf whole-brain model,based on structural connectivity,overcomes limitations of traditional structural or functional connectivity-focused methods by incorporating heterogeneity parameters,quantifying dynamic brain characteristics in healthy and diseased states.Traditional parameter fitting techniques lack precision,restricting broader use.To address this,we validated parameter fitting methods using simulated networks and synthetic models,introducing improvements such as individual-specific initialization and optimized gradient descent,which reduced individual data loss.We also developed an approximate loss function and gradient adjustment mechanism,enhancing parameter fitting accuracy and stability.Applying this refined method to datasets for major depressive disorder(MDD)and autism spectrum disorder(ASD),we identified differences in brain regions between patients and healthy controls,explaining related anomalies.This rigorous validation is crucial for clinical application,paving the way for precise neuropathological identification and novel treatments in neuropsychiatric research,demonstrating substantial potential in clinical neurology.
基金support from the Carnegie Trust for the Universities of ScotlandPRIN 2022597MBS PHERMIACsupported by the European Research Council(ERC)under the European Union Horizon 2020 Research and Innovation Program(Grant Agreement No.819346)。
文摘Optical neural networks(ONNs)are a class of emerging computing platforms that leverage the properties of light to perform ultra-fast computations with ultra-low energy consumption.ONNs often use CCD cameras as the output layer.In this work,we propose the use of perovskite solar cells as a promising alternative to imaging cameras in ONN designs.Solar cells are ubiquitous,versatile,highly customizable,and can be fabricated quickly in laboratories.Their large acquisition area and outstanding efficiency enable them to generate output signals with a large dynamic range without the need for amplification.Here we have experimentally demonstrated the feasibility of using perovskite solar cells for capturing ONN output states,as well as the capability of single-layer random ONNs to achieve excellent performance even with a very limited number of pixels.Our results show that the solar-cell-based ONN setup consistently outperforms the same setup with CCD cameras of the same resolution.These findings highlight the potential of solar-cell-based ONNs as an ideal choice for automated and battery-free edge-computing applications.
基金support of a MURI project from the U.S.Air Force Office of Scientific Research(Grant No.FA9550-21-1-0312)A.M.and M.L.are Research Associates of the Fonds de la Recherche Scientifique-FNRS.This work was supported by the Fonds de la Recherche Scientifique-FNRS under Grant MOONSHINE PDR T.0186.24+1 种基金Computational resources have been provided by the Consortium desÉquipements de Calcul Intensif(CECI),funded by the Fonds de la Recherche Scientifique de Belgique(F.R.S.-FNRS)under Grant No.2.5020.11by the Walloon Region.The present research also benefited from computational resources made available on Lucia,the Tier-1 supercomputer of the Walloon Region,infrastructure funded by the Walloon Region under the grant agreement n°1910247.
文摘Twisted bilayer photonic crystals introduce a twist between two stacked photonic crystal slabs,enabling strong modulation of their electromagnetic properties.The change in the twist angle strongly influences the resonant frequencies and available propagating diffraction orders with applications including sensing,lasing,slow light or wavefront engineering.In this work,we design and analyze twisted bilayer crystals capable of steering light in a direction controlled by the twist angle.To achieve beam steering,the device efficiently routes input power into a single,twist-dependent,transmitted diffraction order.The outgoing light then follows the orientation of this diffraction order,externally controlled by the twist angle.Our study shows,using systematic exploration of the design space,how the device resembles blazed gratings by effectively canceling the undesired diffraction orders.The optimized devices exhibit a shared slant dependent on the selected diffraction order and that proves robust to the twist angle.Our analysis is supported by a classical blazing model and a data-oriented statistical analysis.The data-oriented approach is steered by high-efficiency heuristic optimization method,which enabled the design of optimized devices demonstrating an efficiency above 90%across twist angles ranging from 0 to 30°for both TE and TM polarizations.Extending the optimization to include left-and right-handed polarizations yields overall accuracy nearing 90%when averaged across the entire 0 to 60°control range.Finally,with the identification of the blazing effect in this initially black box structure,we show one can consider simpler design for a first prototype.
基金financial support from the European Research Council(ERC)under the European Union's Horizon 2020 research and innovation program(CoEvolve,grant no.851960 for N.A.K.)from the Dutch Research Council(NWO,the Gravitation Program"Materials Driven Regeneration",grant no.024.003.013 for C.V.C.B and N.A.K.)supported by the Italian Association for Cancer Research(AIRC),IG#24976,and by the Italian Ministry of University and Research(MUR)under the European Union's NextGenerationEU program.
文摘During wound healing,fibroblasts undergo radical processes that impact their phenotype and behavior.They are activated,recruited to the injury site,assume a contractile phenotype,and secrete extracellular matrix proteins to orchestrate tissue repair.Thus,fibroblast responses require dynamic changes in cytoskeleton assembly and organization,adhesion morphology,and force generation.At the same time,fibroblasts experience changes in environmental stiffness during tissue wounding and healing.Although cells are generally known to use their adhesioncontraction machinery to sense microenvironmental stiffness,little is known about how stiffness affects the fibroblast phenotypical transition and behavior in wound healing.Here we demonstrate that stiffness plays a deterministic role in determining fibroblast phenotype,surprisingly even overruling the classical TGF-β-mediated stimulation.By combining morphometric analysis,traction force microscopy,and single-cell migration analysis,we show that environmental stiffness primes the cytoskeletal and mechanical responses of fibroblasts,strongly modulating their morphology,force generation,and migration behavior.Our study,therefore,points to the importance of tissue stiffness as a key mechanobiological regulator of fibroblast behavior,thus serving as a potential target for controlling tissue repair.
基金the UMCG Microscopy and Imaging Center(UMIC)for use of microscopy equipment(sponsored by NWO 40-00506-98-9021)the Graduate School Medical Sciences(GSMS).
文摘Understanding cell-material interactions is crucial for advancing biomedical applications,influencing cellular behavior and medical device performance.Material properties can be manipulated to direct cell responses,benefiting applications from regenerative medicine to implantable devices such as silicone breast implants.Knowledge about the interaction differences between healthy and cancer cells with implants may guide implant design to more precisely influence cell adhesion and proliferation of healthy cells while inhibiting cancer cells,tailoring outcomes to specific cellular responses.To show-case this potential,breast epithelial cells and breast cancer cells were investigated regarding their interaction with a broad range of combined physicochemical properties.This study employed a silicone-based high-throughput screening method utilizing Double Orthogonal Gradients(DOGs)to investigate the influence of topography,stiffness,and wettability on breast epithelial cells(MCF10a)and breast cancer cells(MCF7).Results show distinct cellular responses,including decreased prolif-eration rates in both MCF10a and MCF7 cells with the introduction of surface topography and the dominant influence of wettability on cell adhesion,proliferation,and cluster formation.The screening identified specific regions of interest(ROIs)where MCF10a cell proliferation outperformed MCF7 cells and that topography inhibits cluster formation(tumorigenesis),offering potential prospects for the creation of novel implant surfaces.
文摘Animals can modify their body shape and/or color for protection,camouflage and communication.This adaptability has inspired fabrication of actuators with structural color changes to endow soft robots with additional functionalities.Using liquid crystal-based materials for actuators with structural color changes is a promising approach.In this review,we discuss the current state of liquid crystal-based actuators with structural color changes and the potential applications of these structural color actuators in soft robotic devices.
基金This work is financed by the Dutch Ministry of Education,Culture and Science(Gravity program 024.001.035).
文摘Nature has unparalleled control over the conforma-tion and dynamics of its folded macromolecular structures.Nature’s ability to arrange amino acids into a precise spatial organization by way of folding allows proteins to fulfill specific functions in an ex-tremely efficient manner.
基金ERC Advanced Grant Artisym,Grant/Award Number:694120Dutch Ministry of Education,Culture and Science,Grant/Award Number:024.001.035+4 种基金NWO-NSFC Advanced Materials,Grant/Award Number:792.001.015European Union’s Horizon 2020Marie Sklodowska-Curie Innovative Training Networks Nanomed,Grant/Award Number:676137H2020 Marie Sklodowska-Curie Actions,Grant/Award Numbers:Innovative Training Networks Nanomed,(No.,676137)H2020 European Research Council,Grant/Award Number:ERC Advanced Grant Artisym 694120。
文摘Aggregation-induced emission(AIE)is a phenomenon in which fluorescence is enhanced rather than quenched upon molecular assembly.AIE fluorogens(AIEgens)are flexible,conjugated systems that are limited in their dynamics when assembled,which improves their fluorescent properties.This intriguing feature has been incorporated in many different molecular assemblies and has been extended to nanoparticles composed of amphiphilic polymer building blocks.The integration of the fascinating AIE design principle with versatile polymer chemistry opens up new frontiers to approach and solve intrinsic obstacles of conventional fluorescent materials in nanoscience,including the aggregation-caused quenching effect.Furthermore,this integration has drawn significant attention from the nanomedicine community,due to the additional advantages of nanoparticles comprising AIEgenic molecules,such as emission brightness and fluorescence stability.In this regard,a range of AIEgenic amphiphilic polymers have been developed,displaying enhanced emission in the self-assembly/aggregated state.AIEgenic assemblies are regarded as attractive nanomaterials with inherent fluorescence,which display promising features in a biomedical context,for instance in biosensing,cell/tissue imaging and tracking,as well as(photo)therapeutics.In this review,we describe recent strategies for the design and synthesis of novel types of AIEgenic amphiphilic polymers via facile approaches including direct conjugation to natural/synthetic polymers,polymerization,post-polymerization and supramolecular host−vip interactions.Their self-assembly behavior and biomedical potential will be discussed.
基金financial support from the National Science Foundation(DMR-1905818 and REU Grant CHE1062840,USA)the Robert A.Welch Foundation through the W.T.Doherty-Welch Chair in Chemistry(A-0001,USA)。
文摘To expand the single-dose duration over which noninvasive clinical and preclinical cancer imaging can be conducted with high sensitivity,and well-defined spatial and temporal resolutions,a facile strategy to prepare ultrasmall nanoparticulate X-ray contrast media(nano-XRCM)as dual-modality imaging agents for positron emission tomography(PET)and computed tomography(CT)has been established.Synthesized from controlled copolymerization of triiodobenzoyl ethyl acrylate and oligo(ethylene oxide)acrylate monomers,the amphiphilic statistical iodocopolymers(ICPs)could directly dissolve in water to afford thermodynamically stable solutions with high aqueous iodine concentrations(>140 mg iodine/mL water)and comparable viscosities to conventional small molecule XRCM.The formation of ultrasmall iodinated nanoparticles with hydrodynamic diameters of ca.10 nm in water was confirmed by dynamic and static light scattering techniques.In a breast cancer mouse model,in vivo biodistribution studies revealed that the64Cu-chelator-functionalized iodinated nano-XRCM exhibited extended blood residency and higher tumor accumulation compared to typical small molecule imaging agents.PET/CT imaging of tumor over 3 days showed good correlation between PET and CT signals,while CT imaging allowed continuous observation of tumor retention even after 10 days post-injection,enabling longitudinal monitoring of tumor retention for imaging or potentially therapeutic effect after a single administration of nano-XRCM.
文摘Tissue-engineered constructs are promising to overcome shortage of organ donors and to reconstruct at least partsof injured or diseased tissues or organs. However, oxygen and nutrient supply are limiting factors in many tissues,especially after implantation into the host. Therefore, the development of a vascular system prior to implantationappears crucial. To develop a functional vascular system, different cell types that interact with each other need tobe co-cultured to simulate a physiological environment in vitro. This review provides an overview and a comparison ofthe current knowledge of co-cultures of human endothelial cells (ECs) with human adipose tissue-derived stem/stromal cells (ASCs) or bone marrow-mesenchymal stem cells (BMSCs) in three dimensional (3D) hydrogel matrices.Mesenchymal stem cells (MSCs), BMSCs or ASCs, have been shown to enhance vascular tube formation of ECs and toprovide a stabilizing function in addition to growth factor delivery and permeability control for ECs. Althoughphenotypically similar, MSCs from different tissues promote tubulogenesis through distinct mechanisms. In this report,we describe differences and similarities regarding molecular interactions in order to investigate which of these two celltypes displays more favorable characteristics to be used in clinical applications. Our comparative study shows that ASCsas well as BMSCs are both promising cell types to induce vascularization with ECs in vitro and consequently arepromising candidates to support in vivo vascularization.
文摘The amplification of asymmetry from the molecular level to the macroscopic scale is an intriguing mechanism operative in natural systems to control complex functions.Inspired by nature,strategies for transferring chiral information across length scales in purely synthetic systems have been investigated.[1,2]Thereof,chiral molecules are embedded into well-defined ordered supramolecular structures with the dynamics of noncovalent interactions leading to the amplification effect.
基金the support of a grant from the John Templeton Foundation(58277)support by the European Research Council Grant ERC-POC-2014 Vanguard(664782)
文摘The investigation of the interplay between geometry and nonlinearity may open the road to the control of extreme waves. We study three-dimensional localization and dispersive shocks in a bent cigar shaped potential by the nonlinear Schro¨ dinger equation. At high bending and high nonlinearity, topological trapping is frustrated by the generation of curved wave-breaking. Four-dimensional parallel simulations confirm the theoretical model. This work may contribute to novel devices based on geometrically constrained highly nonlinear dynamics and tests and analogs of fundamental physical theories in curved space.
基金Museo Storico della Fisica e Centro Studi e Ricerche Enrico FermiMinistero dell’Universitàe della Ricerca(PRIN No.20177PSCKT)。
文摘Modern machine-learning applications require huge artificial networks demanding computational power and memory.Light-based platforms promise ultrafast and energy-efficient hardware,which may help realize nextgeneration data processing devices.However,current photonic networks are limited by the number of inputoutput nodes that can be processed in a single shot.This restricted network capacity prevents their application to relevant large-scale problems such as natural language processing.Here,we realize a photonic processor for supervised learning with a capacity exceeding 1.5×10^(10)optical nodes,more than one order of magnitude larger than any previous implementation,which enables photonic large-scale text encoding and classification.By exploiting the full three-dimensional structure of the optical field propagating in free space,we overcome the interpolation threshold and reach the over-parameterized region of machine learning,a condition that allows high-performance sentiment analysis with a minimal fraction of training points.Our results provide a novel solution to scale up light-driven computing and open the route to photonic natural language processing.
