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
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
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
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
Synthetic molecules that form functional noncovalent assemblies in water have received much attention for their potential applications as biomaterials.In this work,we introduce a novel water-compatible monomer based o...Synthetic molecules that form functional noncovalent assemblies in water have received much attention for their potential applications as biomaterials.In this work,we introduce a novel water-compatible monomer based on the phthalhydrazide moiety that assembles into hydrogen-bonded trimeric discs.In bulk,the material exhibits a cylindrical nanostructure in the liquid-crystalline phase at elevated temperatures,morphologically distinct from the crystalline lamellar phase.In water,these molecules effectively form cylinders in a one-dimensional fashion,yielding fibrous structures.The formation of these supramolecular polymers follows a cooperative mechanism,as evidenced by denaturation studies.The trimerized pattern represents a new category of aqueous su pramolecular polymers with future prospects for functional complex molecular systems.展开更多
Exploration of multicolor mechanochromic bulk polymers based on a single mechanophore is a big challenge to date.Herein,we report a versatile benzimidazole-substituted spirolactam mechanophore where excited state intr...Exploration of multicolor mechanochromic bulk polymers based on a single mechanophore is a big challenge to date.Herein,we report a versatile benzimidazole-substituted spirolactam mechanophore where excited state intramolecular proton transfer(ESIPT)coupled with rhodamine.The mechanophore was facilely synthesized and then covalently linked to polyurethane(PU)chains.The PU film containing the mechanophore(1@PU)showed cooperative photochromism upon irradiation involving simultaneous enhancement of normalized enol and rhodol emissions based on a cooperative ESIPT process and the ring-opening reaction of spirolactam.Moreover,the film exhibited dual-mode multicolor mechanochromism upon stretching and compression.The normalized intensity of enol emission increased and the fluorescence turned from light green to cyan after stretching,then red coloration appeared from colorless after compressing.Control experiments and density functional theory calculations confirmed that the stretch-induced increase of enol emission was attributed to torsion of the dihedral angle between xanthene and benzimidazole in the mechanophore via force-induced disaggregation and direct force action on the isolated mechanophore.Torsion of the dihedral angle and the ring-opening reaction of spirolactam in a single mechanophore occurred sequentially during compression,resulting in an observed red coloration.This study might provide a glimpse into the design of novel multicolor mechanochromic mechanophores.展开更多
We investigate the chiral emission from non-chiral molecules coupled to metasurfaces with a unit cell formed by dimers of detuned and displaced Si nanodisks.The detuning and displacement lead to the formation of narro...We investigate the chiral emission from non-chiral molecules coupled to metasurfaces with a unit cell formed by dimers of detuned and displaced Si nanodisks.The detuning and displacement lead to the formation of narrow modes,known as quasi-bound states in the continuum(Q-BICs),with different electric and magnetic characteristics.The dispersion and character of the modes are explained by using the guided-mode expansion method and finite-element simulations.The coupling between these modes leads to an extrinsic chiral response with large circular dichroism for defined energies and wavevectors.When the lattice constant of the metasurface is changed,the dispersion of the extrinsic chiral Q-BICs can be tuned and the emission properties of a thin film of dye molecules on top of the metasurface are modified.In particular,we observe strongly directional and circularly polarized emission from the achiral dye molecules with a degree of circular polarization reaching 0.8 at the wavelengths defined by the dispersion of the Q-BICs.These results could enable the realization of compact light sources with a large degree of circular polarization for applications in displays,optical recording,or optical communication.展开更多
Bacteria can be programmed to deliver natural materials with defined biological and mechanical properties for controlling cell growth and differentiation.Here,we present an elastic,resilient and bioactive polysacchari...Bacteria can be programmed to deliver natural materials with defined biological and mechanical properties for controlling cell growth and differentiation.Here,we present an elastic,resilient and bioactive polysaccharide derived from the extracellular matrix of Pantoea sp.BCCS 001.Specifically,it was methacrylated to generate a new photo crosslinkable hydrogel that we coined Pantoan Methacrylate or put simply PAMA.We have used it for the first time as a tissue engineering hydrogel to treat VML injuries in rats.The crosslinked PAMA hydrogel was super elastic with a recovery nearing 100%,while mimicking the mechanical stiffness of native muscle.After inclusion of thiolated gelatin via a Michaelis reaction with acrylate groups on PAMA we could also guide muscle progenitor cells into fused and aligned tubes-something reminiscent of mature muscle cells.These results were complemented by sarcomeric alpha-actinin immunostaining studies.Importantly,the implanted hydrogels exhibited almost 2-fold more muscle formation and 50%less fibrous tissue formation compared to untreated rat groups.In vivo inflammation and toxicity assays likewise gave rise to positive results confirming the biocompatibility of this new biomaterial system.Overall,our results demonstrate that programmable polysaccharides derived from bacteria can be used to further advance the field of tissue engineering.In greater detail,they could in the foreseeable future be used in practical therapies against VML.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 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
Topological photonics has been opening exciting opportunities in recent optics research.In this feature issue,we present a collection of papers outlining state-of-the-art and application perspectives for this thriving...Topological photonics has been opening exciting opportunities in recent optics research.In this feature issue,we present a collection of papers outlining state-of-the-art and application perspectives for this thriving field of research.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funding from the European Research Council(H2020-EU.1.1.,SYNMAT project,ID 788618)the Dutch Ministry of Education,Culture and Science(Gravitation Program 024.001.035).
文摘Synthetic molecules that form functional noncovalent assemblies in water have received much attention for their potential applications as biomaterials.In this work,we introduce a novel water-compatible monomer based on the phthalhydrazide moiety that assembles into hydrogen-bonded trimeric discs.In bulk,the material exhibits a cylindrical nanostructure in the liquid-crystalline phase at elevated temperatures,morphologically distinct from the crystalline lamellar phase.In water,these molecules effectively form cylinders in a one-dimensional fashion,yielding fibrous structures.The formation of these supramolecular polymers follows a cooperative mechanism,as evidenced by denaturation studies.The trimerized pattern represents a new category of aqueous su pramolecular polymers with future prospects for functional complex molecular systems.
基金financially supported by the National Natural Science Foundation of China (grant nos.22375013,22175015,and 21704002)the Beijing Natural Science Foundation (grant no.2182054)+1 种基金the Big Science Project from BUCT (grant no.XK180301)the Fundamental Research Funds for the Central Universities to Z.Y.Ma.
文摘Exploration of multicolor mechanochromic bulk polymers based on a single mechanophore is a big challenge to date.Herein,we report a versatile benzimidazole-substituted spirolactam mechanophore where excited state intramolecular proton transfer(ESIPT)coupled with rhodamine.The mechanophore was facilely synthesized and then covalently linked to polyurethane(PU)chains.The PU film containing the mechanophore(1@PU)showed cooperative photochromism upon irradiation involving simultaneous enhancement of normalized enol and rhodol emissions based on a cooperative ESIPT process and the ring-opening reaction of spirolactam.Moreover,the film exhibited dual-mode multicolor mechanochromism upon stretching and compression.The normalized intensity of enol emission increased and the fluorescence turned from light green to cyan after stretching,then red coloration appeared from colorless after compressing.Control experiments and density functional theory calculations confirmed that the stretch-induced increase of enol emission was attributed to torsion of the dihedral angle between xanthene and benzimidazole in the mechanophore via force-induced disaggregation and direct force action on the isolated mechanophore.Torsion of the dihedral angle and the ring-opening reaction of spirolactam in a single mechanophore occurred sequentially during compression,resulting in an observed red coloration.This study might provide a glimpse into the design of novel multicolor mechanochromic mechanophores.
基金Funded by the European Union(SCOLED Grant Agreement Number 101098813)Funded by the Dutch Organization for Scientific Research(NWO)through the Gravitation Grant Research Centre for Integrated Nanophotonics+4 种基金financial support from Italian MUR through PNRR project PE0000023-NQSTIfinancial support from Spanish Ministerio de Ciencia,Innovación y Universidades and Agencia Estatal de Investigación(MCIN/AEI/10.13039/501100011033)the financial support from NextGenerationEU(CONVREC-2021-23)financial support from the Bilateral Joint Research Project(JPJSBP120239921)from Japan Society for the Promotion of Sciencefinancial support from the China Scholarship Council(CSC202206320284)。
文摘We investigate the chiral emission from non-chiral molecules coupled to metasurfaces with a unit cell formed by dimers of detuned and displaced Si nanodisks.The detuning and displacement lead to the formation of narrow modes,known as quasi-bound states in the continuum(Q-BICs),with different electric and magnetic characteristics.The dispersion and character of the modes are explained by using the guided-mode expansion method and finite-element simulations.The coupling between these modes leads to an extrinsic chiral response with large circular dichroism for defined energies and wavevectors.When the lattice constant of the metasurface is changed,the dispersion of the extrinsic chiral Q-BICs can be tuned and the emission properties of a thin film of dye molecules on top of the metasurface are modified.In particular,we observe strongly directional and circularly polarized emission from the achiral dye molecules with a degree of circular polarization reaching 0.8 at the wavelengths defined by the dispersion of the Q-BICs.These results could enable the realization of compact light sources with a large degree of circular polarization for applications in displays,optical recording,or optical communication.
基金the Danish Council for Independent Research(Technology and Production Sciences,8105-00003B)Denmark,the Novo Nordisk Foundation(NNF22OC0079994 in the call"Project Grants in the Natural and Technical Sciences 2022)+2 种基金Denmark,and the VIDI research programme with project number R0004387which is(partly)financed by The Netherlands Organization for Scientific Research(NWO),The Netherlands.This work has also received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement no.951747Masoud Hasany and Mehdi Mehrali would like to acknowledge the European Union’s Horizon 2020 research and innovation program under the Marie Skłodowska-Curie grant agreement No 899987.
文摘Bacteria can be programmed to deliver natural materials with defined biological and mechanical properties for controlling cell growth and differentiation.Here,we present an elastic,resilient and bioactive polysaccharide derived from the extracellular matrix of Pantoea sp.BCCS 001.Specifically,it was methacrylated to generate a new photo crosslinkable hydrogel that we coined Pantoan Methacrylate or put simply PAMA.We have used it for the first time as a tissue engineering hydrogel to treat VML injuries in rats.The crosslinked PAMA hydrogel was super elastic with a recovery nearing 100%,while mimicking the mechanical stiffness of native muscle.After inclusion of thiolated gelatin via a Michaelis reaction with acrylate groups on PAMA we could also guide muscle progenitor cells into fused and aligned tubes-something reminiscent of mature muscle cells.These results were complemented by sarcomeric alpha-actinin immunostaining studies.Importantly,the implanted hydrogels exhibited almost 2-fold more muscle formation and 50%less fibrous tissue formation compared to untreated rat groups.In vivo inflammation and toxicity assays likewise gave rise to positive results confirming the biocompatibility of this new biomaterial system.Overall,our results demonstrate that programmable polysaccharides derived from bacteria can be used to further advance the field of tissue engineering.In greater detail,they could in the foreseeable future be used in practical therapies against VML.
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.
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.
文摘Topological photonics has been opening exciting opportunities in recent optics research.In this feature issue,we present a collection of papers outlining state-of-the-art and application perspectives for this thriving field of research.
