查看更多>>摘要：In the inflammatory peri-implant microenvironment, excessive polarization of macrophages to the proinflammatory M1 phenotype can trigger the secretion of inflammatory cytokines, which promote bone resorption and impede osteogenesis around implants. The direct consequence of this process is the failure of prosthetic implants due to aseptic loosening. To reverse the inflammatory microenvironment and prevent prosthesis loosening, a mussel adhesion-inspired surface strategy was used for bioengineering of titanium implants with integrin-binding ability. In our design, a mussel-inspired catecholic peptide with tetravalent 3,4-dihydroxy-L-phenylalanine (DOPA) and Arg-Gly-Asp (RGD) sequences was synthesized. The peptide can easily anchor to the surface of medical titanium materials through a mussel adhesive mechanism. We found that peptide-decorated titanium implants could effectively inhibit peri-implant inflammation in a wear particle model and could promote the polarization of macrophages to a pro-healing M2 phenotype by interfering with integrin-alpha(2)beta(1) and integrin-alpha v beta(3). Moreover, the peptide coating increased the adherence of osteoblasts and promoted osteogenesis on titanium implants even under inflammatory conditions. This work suggested that this biomimetic catecholic integrin-binding peptide can provide facile tactics for surface bioengineering of medical prostheses with improved interfacial osteogenesis under inflammatory conditions, which might contribute greatly to the prevention of pros- thesis loosening and the improvement of clinical outcomes. (C) 2021 Elsevier Inc. All rights reserved.
查看更多>>摘要：Latent fingerprint recognition technique has received increasing attention because it helps to precisely identify human information for many applications. In this study, bifunctional core-shell magnetic fluorescent microspheres have been synthesized via a facile interface Pechini-type sol-gel method using citric acid and polyethylene glycol as chelating agent and cross-linking agent, respectively. The obtained Fe3O4@YVO4:Eu3+ microspheres possess a typical core-shell structure, large magnetization, and strong fluorescence emission. The surface morphology and roughness of the microspheres can be flexibly tuned by controlling the multistep interface deposition process and subsequent calcination temperatures. Due to their well-integrated bifunctionalities, these magnetic fluorescent microspheres show outstanding performance in the visualization of latent fingerprints on various substrates with high definition and excellent anti-interference, and therefore they have great potential for application in identity recognition. (C) 2021 Elsevier Inc. All rights reserved.
查看更多>>摘要：As a promising intercalation material for capacitive deionization (CDI), Prussian blue (PB) and its analogues (PBAs) have the superiority of high theoretical capacity and easy synthesis. But they often suffer from low conductivity and severe crystal phase transition, resulting in inferior desalination capacity and poor cycling stability. Herein, the dual strategy of structural optimization and carbon-based materials introduction is proposed to enhance the desalination performance of PBAs. Stepwise hollow structure formed by surface etching has been proved to be more outstanding than cubic structure. Enlarged the specific surface area, the contact area with the electrolyte increases, therefore, more active sites are exposed. Besides, the etching of external surfaces provides more buffer space, improves the tolerance to crystal phase transition, and enhances the cycling stability. The introduction of carbon nanotubes brings high conductivity. Specifically, the desalination test shows that stepwise hollow Prussian blue/carbon nanotubes composite delivers a high desalination capacity of 103.4 mg g(-1) with outstanding cycling stability. Moreover, the low energy consumption of 0.23 Wh g(-1) is also suitable for practical application. The dual strategy opens a window to design advanced electrode materials for CDI. (C) 2021 Published by Elsevier Inc.
查看更多>>摘要：Hypothesis: Solid-state polymer adsorption offers a distinct approach for surface modification. These ultrathin, so-called Guiselin layers can easily be obtained by placing a polymer melt in contact with an interface, followed by a removal of the non-adsorbed layer with a good solvent. While the mechanism of formation has been well established for Guiselin layers, their stability, crucial from the perspective of materials applications, is not. The stability is a trade-off in the entropic penalty between cooperative detachment of the number of segments directly adsorbed on the substrate and consecutively pinned monomers. Experiments: Experimental model systems of Guiselin layers of polystyrene (PS) on silicon wafers with native oxide layer on top were employed. The stability of the adsorbed layers was studied as a function of PS molecular weight and polydispersibility by various microscopic and spectroscopic tools as well as quasi-static contact angle measurements. Findings: Adsorbed layers from low molecular weight PS were disrupted with typical spinodal decomposition patterns whereas high molecular weight (>500 kDa) PS resulted in stable, continuous layers. Moreover, we show that Guiselin layers offer an enticing way to modify a surface, as demonstrated by adsorbed PS that imparts a hydrophobic character to initially hydrophilic silicon wafers. (c) 2021 The Author(s). Published by Elsevier Inc. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
查看更多>>摘要：Currently, it is critical but a tricky point to develop economical, high-efficiency, and durable non-precious metal electrocatalysts towards oxygen reduction and oxygen evolution reaction (ORR/OER) in rechargeable Zn-air batteries. Herein, N, Mn-codoped three-dimensional (3D) fluffy porous carbon nanostructures encapsulating FeCo/FeCoP alloyed nanoparticles (FeCo/FeCoP@NMn-CNS) are prepared by one-step pyrolysis of the metal precursors and polyinosinic acid. The optimized hybrid nanocomposite (obtained at 800 degrees C, named as FeCo/FeCoP@NMn-CNS-800) exhibits outstanding catalytic performance in the alkaline electrolyte with a half-wave potential (E-1/2) of 0.84 V for the ORR and an overpotential of 325 mV towards the OER at 10 mA cm(-2). Impressively, the FeCo/FeCoP@NMn-CNS-800-assem bled rechargeable Zn-air battery presents an open-circuit voltage of 1.522 V (vs. RHE), a peak power density of 135.0 mW cm(-2), and long-term durability by charge-discharge cycling for 200 h, surpassing commercial Pt/C + RuO2 based counterpart. This work affords valuable guidelines for exploring advanced bifunctional ORR and OER catalysts in rational construction of high-quality Zn-air batteries. (C) 2021 Elsevier Inc. All rights reserved.
查看更多>>摘要：The effect of the chemical component and microstructure, not to mention their facile modification, of the coating/wrapping carbon layer on the electrochemical performance of the Si/C composite anode in lithium ion batteries (LIBs) hasn't been actively explored although Si/C has been recognized as one of the most promising route for the high energy density LIBs. Herein we propose a novel nitrogen-plasma doping route to modify the top carbon film in an elaborately constructed layered Si/C composite anode. The electrochemical performance, e.g., the initial coulombic efficiency (CE), cycle stability and specific capacity of the composite anode is drastically improved by this plasma processing due to the increased kinetics of lithium ions. By means of the appropriate adjustment of the N doping ratio and N chemical configuration in the carbon layer through a N-2/H-2 plasma processing, the lithium diffusion rate in the composite anode was memorably increased as the pseudocapacitance effects promoted. The optimized Si/C composite exhibits a high capacity of 1120.7 mA h g(-1) and an initial CE of 80.8% at the current of 2 A g(-1) after a long cycle of 1500, increasing by similar to 40% of specific capacity and similar to 29% of the initial CE. (C) 2021 Elsevier Inc. All rights reserved.
查看更多>>摘要：Molybdenum disulfide (MoS2) has possession of a layered structure and high theoretical capacity, which is a candidate anode material for sodium ion batteries. However, unmodified MoS2 are inflicted with a poor cycling stability and an inferior rate capability upon charge/discharge processes. Considering that the shape and size of anode materials play a key role in the performance of anode materials, this paper proposes a multi-level composite structure formed by the micro-nano materials based on self-assembled molybdenum disulfide (MoS2) nanoflowers, Mxene and hollow carbonized kapok fiber (CKF). The micro-nano materials can be connected to form heterojunction and agglomeration can be avoided. The load bearing of heterostructure and stress release of CKF are coordinated to form a double protection mechanism, which improves the conductivity and structural stability of hybrid materials. Based on the above advantages, it has higher specific capacity than pure MoS2, and has better rate performance (639.3, 409.5, 386.2, 372, 338, 422.8 and 434.7 mAh g(-1) at the current density of 0.05, 0.1, 0.2, 0.5,1 ,0.1 and 0.05 A.g(-1), respectively). The stress-modulated strategies can provide new insights for the design and construction of transition metal sulfides heterostructures to achieve high performance sodium ion batteries. (C) 2021 Elsevier Inc. All rights reserved.
查看更多>>摘要：The conductive networks for electron hopping and migration constructed by one-dimensional (1D) composite absorbers are highly desirable to improve the electromagnetic (EM) wave attenuation capacity. Herein, the Ni@Co/C@polypyrrole (PPy) composites integrating the advantages of component and microstructure were fabricated. The addition of Co/C and PPy effectively optimized the impedance matching and improved the EM attenuation. Under the comprehensive impacts of multiple reflections/ scattering, conduction loss and interface polarization, the Ni@Co/C@PPy composites showed superior EM wave absorption with the reflection loss (RL) value of-48.76 dB and the effective absorption bandwidth (EAB) of 5.10 GHz at a corresponding thickness of 2.0 mm. The largest EAB could reach 5.54 GHz (7.24-12.78 GHz) at the thickness of 2.2 mm. This work provides a great reference for fabricating 1D novel EM wave absorption materials. (c) 2021 Elsevier Inc. All rights reserved.
查看更多>>摘要：The interaction of proteins and peptides with inorganic surfaces is relevant in a wide array of technolog-ical applications. A rational approach to design peptides for specific surfaces would build on amino-acid and surface specific interaction models, which are difficult to characterize experimentally or by model-ing. Even with such a model at hand, the large number of possible sequences and the large conformation space of peptides make comparative simulations challenging. Here we present a computational protocol, the effective implicit surface model (EISM), for efficient in silico evaluation of the binding affinity trends of peptides on parameterized surface, with a specific application to the widely studied gold surface. In EISM the peptide surface interactions are modeled with an amino-acid and surface specific implicit solvent model, which permits rapid exploration of the peptide conformational degrees of freedom. We demon-strate the parametrization of the model and compare the results with all-atom simulations and experi-mental results for specific peptides. (c) 2021 Published by Elsevier Inc.
查看更多>>摘要：Herein, we report for the first time a facile strategy for the highly efficient (NH4)(x)Cs1-xPbBr3 quantum dots (QDs). By modulating the amount of ammonium, (NH4)(x)Cs1-xPbBr3 QDs with different photoluminescence (PL) quantum yields (QY) were synthesized. The results of X-ray diffraction and X-ray photoelectron spectroscopy showed that the crystal structure of (NH4)(x)Cs1-xPbBr3 was altered by incorporation of NH4+ cations into the CsPbBr3Y lattice. The (NH4)(x)Cs1-xPbBr3 QDs showed enhanced PL QY, higher photostability, and long-term storage stability compared to CsPbBr3 QDs. Furthermore, (NH4)(x)Cs1-xPbBr3 QDs could be conjugated with a photothermal dye (IR780) via a one-pot reaction using poly(styrene-co-maleic anhydride) and IR780-MPTS. To the best of our knowledge, the present work is the first attempt integrating perovskite QDs and phototherapeutic molecules into one system (abbreviated as PQD-IR780), demonstrating good water dispersibility and high photothermal conversion efficiency of 57.85%. In vitro experiments performed to examine subcellular uptake showed high fluorescence brightness was observed in HeLa, B16F1, and HepG2 cancer cells cultured with PQD-IR780. The results indicate that the internalization mechanism for uptaking of PQD-IR780 inside HeLa cells is energy-dependent and caveolin-mediated endocytosis. The in vitro cell viability assays and photothermal therapy revealed that PQD-IR780 showed good biocompatibility and can induce hyperthermia upon laser irradiation. (C) 2021 Elsevier Inc. All rights reserved.
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