Passivation engineering via silica‐encapsulated quantum dots for highly sensitive photodetection

Organometal halide perovskites are promising semiconducting materials for photodetectors because of their favorable optoelectrical properties.Although nanoscale perovskite materials such as quantum dots(QDs)show novel behavior,they have intrinsic stability issues.In this study,an effectively silane barrier-capped quantum dot(QD@APDEMS)is thinly applied onto a bulk perovskite photosensitive layer for use in photodetectors.QD@APDEMS is synthesized with a silane ligand with hydrophobic CH_(3)-terminal groups,resulting in excellent dispersibility and durability to enable effective coating.The introduction of the QD@APDEMS layer results in the formation of a lowdefect perovskite film with enlarged grains.This is attributed to the grain boundary interconnection effect via interaction between the functional groups of QD@APDEMS and uncoordinated Pb^(2+)in grain boundaries.By passivating the grain boundaries,where various trap sites are distributed,hole chargecarrier injection and shunt leakage can be suppressed.Also,from the energy point of view,the deep highest occupied molecular orbital(HOMO)level of QD@APDEMS can work as a hole charge injection barrier.Improved charge dynamics(generation,transfer,and recombination properties)and reduced trap density of QD@APDEMS are demonstrated.When this perovskite film is used in a photodetector,the device performance(especially the detectivity)stands out among existing perovskites evaluated for energy sensing device applications.

Recent progress and future research directions for electrochromic zinc-ion batteries

In recent times,future energy storage systems demand a multitude of functionalities beyond their traditional energy storage capabilities.In line with this technological shift,there is active research and development of electrochromic-energy storage systems designed to visualize electrochemical charging and discharging processes.The conventional electrochromic-energy storage devices primarily integrated supercapacitors,known for their high power density,to enable rapid color contrast.However,the low energy density of supercapacitors restricts overall energy storage capacity,acting as a significant barrier to expanding the application range of such systems.In this review,we introduce electrochromic zinc(Zn)-ion battery systems,which effectively overcome the limitation of low energy density,and provide illustrative examples of their applicability across diverse fields.Although many recent research works are present for electrochromic Zn-ion batteries,little review has so far taken place.Our objective is to discuss on the current progress and future directions for electrochromic Zn-ion batteries,which are applicable for wearable electronics applications and energy storage systems.This review provides an initial milestone for future researchers in electrochromic energy storage and zinc-ion batteries,which will lead to a stream of future works related to them.

Clustering Reference Images Based on Covisibility for Visual Localization

In feature-based visual localization for small-scale scenes,local descriptors are used to estimate the camera pose of a query image.For large and ambiguous environments,learning-based hierarchical networks that employ local as well as global descriptors to reduce the search space of database images into a smaller set of reference views have been introduced.However,since global descriptors are generated using visual features,reference images with some of these features may be erroneously selected.In order to address this limitation,this paper proposes two clustering methods based on how often features appear as well as their covisibility.For both approaches,the scene is represented by voxels whose size and number are computed according to the size of the scene and the number of available 3Dpoints.In the first approach,a voxel-based histogram representing highly reoccurring scene regions is generated from reference images.A meanshift is then employed to group the most highly reoccurring voxels into place clusters based on their spatial proximity.In the second approach,a graph representing the covisibility-based relationship of voxels is built.Local matching is performed within the reference image clusters,and a perspective-n-point is employed to estimate the camera pose.The experimental results showed that camera pose estimation using the proposed approaches was more accurate than that of previous methods.

Glycan targeting nanoparticle for photodynamic immunotherapy of melanoma

Interaction between tumour cells and macrophages enables cancer cells to evade immune detection and clearance by interfering with macrophage phagocytosis.The anti-phagocytic signals regulated by anti-phagocytic proteins are termed"don't eat me"signals;these signals include sialic acidbinding immunoglobulin-type lectin-10(Siglec-10)and the recently revealed CD24 immune checkpoint(ICP).In this study,we demonstrate that targeting a specific glycan on CD24 exhibits the potential to inhibit ICP.Sambucus nigra agglutinin(SNA),a sialic acid-binding lectin,was employed to block CD24 and to enhance phagocytosis in melanoma tumours.In addition,we prepared SNA-conjugated hollow gold-iron oxide nanoparticles for photothermal therapy of tumours.Our findings show that the combination treatment of SNA-conjugated photothermal nanoparticles and near-infrared exposure successfully augments tumour cell phagocytosis both in vitro and in vivo models.

Vacuum-free lamination via controlled polymer adhesion for selective photogeneration and photodetection

This study attempts to develop a reproducible thin-film formation technique called vacuum-free(VF)lamination,which transfers thin films using elastomeric polymer-based laminating mediators.Precisely,by controlling the interface characteristics of the mediator based on the work of adhesion,VF lamination is successfully performed for various thicknesses(from 20 to 240 nm)of a conjugated photoactive material composed of poly[(2,6-(4,8-bis(5-(2-ethylhexyl-3-fluoro)thiophen-2-yl)-benzo[1,2-b:4,5-bʹ]dithiophene))-alt-(5,5-(1ʹ,3ʹ-di-2-thienyl-5ʹ,7ʹ-bis(2-ethylhexyl)benzo[1ʹ,2ʹ-c:4ʹ,5ʹ-cʹ]dithiophene-4,8-dione)](a polymer donor)and 2,2ʹ-((2Z,2ʹZ)-((12,13-bis(2-butyloctyl)-3,9-diundecyl-12,13-dihydro-[1,2,5]thiadiazolo[3,4-e]thieno[2ʹʹ,3ʹʹ:4ʹ,5ʹ]thieno[2ʹ,3ʹ:4,5]pyrrolo[3,2-g]thieno[2ʹ,3ʹ:4,5]thieno[3,2-b]indole-2,10-diyl)bis(methanylylidene))bis(5,6-difluoro-3-oxo-2,3-dihydro-1H-indene-2,1-diylidene))dimalononitrile(a nonfullerene acceptor).Interestingly,the organic photovoltaic and photodetecting applications,prepared by the VF lamination process,showed superior performance compared to those of devices prepared by conventional spin-coating.This is due to the overturned surface morphology,which led to enhanced charge transport ability and blocking of the externally injected charge.Thus,the reproducible VF lamination process,exploiting an adhesion-based elastomeric polymer mediator,is a promising thin-film formation technique for developing efficient next-generation organic optoelectronic materials consistent with the solution process.

Electrically controlled mRNA delivery using a polypyrrolegraphene oxide hybrid film to promote osteogenic differentiation of human mesenchymal stem cells

Direct messenger ribonucleic acid(mRNA)delivery to target cells or tissues has revolutionized the field of biotechnology.However,the applicability of regenerative medicine is limited by the technical difficulties of various mRNA-loaded nanocarriers.Herein,we report a new conductive hybrid film that could guide osteogenic differentiation of human adipose-derived mesenchymal stem cells(hADMSCs)via electrically controlled mRNA delivery.To find optimal electrical conductivity and mRNAloading capacity,the polypyrrole-graphene oxide(PPy-GO)hybrid film was electropolymerized on indium tin oxide substrates.We found that the fluorescein sodium salt,a molecule partially mimicking the physical and chemical properties of mRNAs,can be effectively absorbed and released by electrical stimulation(ES).The hADMSCs cultivated on the PPy-GO hybrid film loaded with pre-osteogenic mRNAs showed the highest osteogenic differentiation under electrical stimulation.This platform can load various types of RNAs thus highly promising as a new nucleic acid delivery tool for the development of stem cell-based therapeutics.

Graphene foam/hydrogel scaffolds for regeneration of peripheral nerve using ADSCs in a diabetic mouse model

The functional recovery of peripheral nerve injury(PNI)is unsatisfactory,whereas diabetes mellitus(DM)and its related complications further attenuate the restoration of diabetic PNI(DPNI).Adipose-derived stem cells(ADSCs)are promising candidates for treatment of DPNI due to their abundant source,excellent differentiation and paracrine ability.Our results showed that ADSCs remarkably enhanced the proliferation and migration of Schwann cells and endothelial cells,and tube formation.Mechanistically,ADSCs could regulate Nrf2/HO-1,NF-κB and PI3K/AKT/mTOR signaling pathways,showing multiple functions in reducing oxidative stress and inflammation,and regulating cell metabolism,growth,survival,proliferation,angiogenesis,differentiation of Schwann cell and myelin formation.In current study,novel graphene foam(GF)/hydrogel-based scaffold was developed to deliver ADSCs for treatment of DPNI.GF/hydrogel scaffold exhibited excellent mechanical strength,suitable porous network,superior electrical conductivity,and good biocompatibility.In vitro results revealed that GF/hydrogel scaffold could obviously accelerate proliferation of Schwann cells.Moreover,in vivo experiments demonstrated that ADSCs-loaded GF/hydrogel scaffold significantly promoted the recovery of DPNI and inhibited the atrophy of targeted muscles,thus providing a novel and attractive therapeutic approach for DPNI patients.

Imaging atomic-scale chemistry from fused multi-modal electron microscopy

Efforts to map atomic-scale chemistry at low doses with minimal noise using electron microscopes are fundamentally limited by inelastic interactions.Here,fused multi-modal electron microscopy offers high signal-to-noise ratio(SNR)recovery of material chemistry at nano-and atomic-resolution by coupling correlated information encoded within both elastic scattering(high-angle annular dark-field(HAADF))and inelastic spectroscopic signals(electron energy loss(EELS)or energy-dispersive x-ray(EDX)).By linking these simultaneously acquired signals,or modalities,the chemical distribution within nanomaterials can be imaged at significantly lower doses with existing detector hardware.In many cases,the dose requirements can be reduced by over one order of magnitude.This high SNR recovery of chemistry is tested against simulated and experimental atomic resolution data of heterogeneous nanomaterials.