Articles in 2019

Double perovskites have a wide range of properties and a corresponding broad range of potential applications, including magneto-optic and spintronic devices. However, their electric, magnetic, and elastic properties are strongly dependent on the ordered arrangement of cations in the double perovskite structure. In this work we show that the particular crystallization and growth process conditions (very slow rate, close to thermodynamic equilibrium conditions) of Polymer Assisted Deposition (PAD), promote very high B-site cationic ordering. Confirmation of the achievement of full Co/Mn cationic ordering is found in PAD grown epitaxial La₂CoMnO₆/SrTiO₃double perovskite thin films displaying optimal magnetic properties.

Data retention ability and cycle numbers are the decisive properties of phase change materials in applications. Combining in-situ heating transmission electron microscopy techniques with ab-initial calculations, we investigated the phase transitions of binary Sb-Te compounds. The results revealed that Sb vacancies stabilize the cubic framework while the Te vacancies tend to destroy it. This distinguished difference originates from the distribution of antibonding electrons. Reducing Sb vacancies greatly raised the phase transition temperatures of both amorphous-cubic and cubichexagonal phases and therefore may improve the data retention ability and the cyclability of phase change materials.

This study examined the efficiency of co-delivering albendazole (Abz) and silver nanoparticles in suppressing glioma growth. For this purpose, we conjugated menthol, shown to relax the BBB, to bovine serum albumin loaded the complex with Abz and silver nanoparticles. The nanoparticles efficiently crossed the BBB, and specifically accumulated in glioma regions, where they induced glioma cell apoptosis. This effect was mediated by BBB disruption and internalization, and further by blocking ATP generation via inhibition of the glycolytic and mitochondrial pathways. The anti-glioma mechanisms of the nanoparticles involved cytotoxicity, proliferation inhibition, cell cycle arrest, and apoptosis induced by ATP depletion.

We report on the fabrication and characteristics of an individually addressable GaN microdisk LED array in free-standing and ultrathin form. GaN microdisk array was grown on graphene microdots, and the microstructures coated with a polyimide layer were easily separated from the substrate to form an ultrathin free-standing film. Crossbar configuration of metal leads enabled each microdisk LED in an array to be uniquely addressable. The devices in free-standing form exhibited stable electrical and optoelectronic characteristics under extreme bending conditions and continuous operation mode despite the absence of a heat dissipating substrate.

Schematic introduction of nanodiamond/polycaprolactone nerve bridge manufacturing process and in vivo performance. The nanodiamond incorporated into concentrical triple-layered structure provided appropriate elasticity and receptivity. In addition, this scaffold regenerated peripheral nerves and induced macrophage polarization in vivo.

Spin transport is the key process for the operation of spinbased devices. Here the recent progress of spin transport in antiferromagnetic insulators (AFMI) is briefed. The observations of the temperature dependence of spin transmission, spin current switching in AFMI and the negative spin Hall magnetoresistance are discussed. The challenges for developing the functionality of antiferromagnetic insulator as well as the unresolved problems from the experimental observations are also discussed.

To address the inherent hydrophobic and bioinert natures of synthetic polymeric membranes, we design and construct bioinspired and osteopromotive polydopamine nanoparticle-incorporated fibrous membranes through co-electrospinning of polycaprolactone (PCL) with polydopamine nanoparticles (PDA NPs). The multifunctional membranes are demonstrated to possess prominent cytocompatibility and osteo-differentiation potential of human mesenchymal stem cells (hMSCs) without any growth factors, as well as boosted bone regeneration in vivo using a mouse calvarial critical-sized defect. Accordingly, such engineered PDA/PCL fibrous membranes, which are osteoinductive and easy to transplant, have great potential for guided tissue regeneration application.

The proposed vibrating EMNPs (enteric-coated magnetic nanoparticles) treatment can effectively accelerate intestinal peristalsis, reduce the absorption, especially to water-soluble molecule. It has effects both on weight-loss and alcohol-detoxification. 3D-printed device can provide a tunable magnetic power resulting tailored effect of weight-loss.

We report a kind of functional dendrisomes constructed by amphiphilic dendrimers, which enable to enhance cellular uptake by breast cancer stem cells (CSCs), to differentiate breast CSCs by carrying all-trans retinoic acid (ATRA), and to increase anticancer efficacy by carrying ATRA and docetaxel in vitro and in breast cancer-bearing mice. The study further reveals endocytosis mechanism, and uncovers differentiation mechanism by analyzing relevant signal molecules, transcription factors, and cell cycle associated signaling pathway. Hence, the present study offers a novel type of functional dendrisomes for differentiation therapy of breast CSCs, and has a significant clinical implication.

Laser trapping chemistry is applied to synthesize single crystals of pure and mixed halide lead perovskites in a temporally- and spatially- controlled manner. Thus, we obtain perovskite crystals with controlled band gap or photoluminescence color. The formation mechanism of a perovskite crystal is discussed in terms of an increased rate of chemical reaction of precursors collected by the trapping leaser.

Spinodal decomposition, spontaneous phase separation process for periodic lamellae at the nanometer scale, of correlated oxides (Ti, V)O₂ systems offers a sophisticated route to achieve new class of mesoscale structure in the form of self-assembled superlattices. Here, we achieve the tunable self-assembly of (Ti, V)O₂ superlattices with steep metal-insulator transition (ΔT_MI < 5 K) by spinodal decomposition with accurate control of growth parameters. Increase in a film growth rate thickens a lamellae period; the phase separation were kinetically enhanced by adatom impingement during two-dimensional growth, demonstrating that interplay between mass transport and uphill diffusion yields highly periodic (Ti, V)O₂ superlattices.

This perspective highlights various representative manufacturing methods of 3D microelectronic devices and their specific features/limitations. It offers an outlook on future developments in the manufacturing of 3D multifunctional microelectronics devices, and provides some perspectives on the remaining challenges as well as possible solutions. Mechanically guided 3D assembly based on compressive buckling is proposed as a versatile platform that can be merged with micromanufacturing technologies and/or other assembly methods to provide access to microelectronic devices with more types of integrated functions and highly increased densities of functional components.

In this work, we confirmed that an in situ–forming click-crosslinked hyaluronic acid (Cx-HA) hydrogel with chemical immobilization of cytomodulin-2 (CM) (Cx-HA-CM) and human periodontal ligament stem cells (hPLSCs) have a good potential for cartilage tissue engineering. The CM that is retained inside the Cx-HA hydrogel for a long time synergistically induces chondrogenic differentiation of hPLSCs. Therefore, such an injectable formulation of the Cx-HA-CM–based hydrogel proposed in this work provides an opportunity to satisfy the unmet need for (pre)clinical repair of damaged articular cartilage.

We produced a human recombinant Hsp70-1A fused with the cell-penetrating peptide Tat (Tat-Hsp70-1A), that was neuroprotective in vitro against the dopaminergic toxin 6-hydroxydopamine (6-OHDA). We developed and characterized a Tat-Hsp70-1A delivery system by exploiting an injectable, biocompatible, biodegradable semi-interpenetrating polymer network composed of collagen (COLL) and low-molecular-weight hyaluronic acid (LMW HA), structured with gelatin particles. Tat-Hsp70-1A diffused from the selected COLL-LMW HA composites in an active form and protected dopaminergic cells and neurons in Parkinson’s disease (PD) models. Furthermore, Tat-Hsp70-loaded composites conveyed neuroprotection both at behavioral and dopaminergic neuronal level against striatal injection of 6-OHDA.

Three-dimensional (3D) priming, which encapsulates human adipose derived stem cells into hydrogel systems, greatly reduces the amount of time required to induce an efficient retroviral transduction compared with the conventional two-dimensional (2D) method. This facilitating effect is closely related to the acceleration of cell cycle regulation (G1 arrest and G1/S transition) by 3D priming.

With two-thirds of the primary energy produced every year rejected as heat, the need for techniques that harvest low-grade waste heat with higher fractions of Carnot efficiency is clear. This article develops a perspective on pyroelectric energy conversion (PEC), that leverages the intrinsic coupling between electrical polarization and temperature in pyroelectric materials where a change in temperature begets a flow of electrical charge. This article will shed light on what thermo-electrical properties are crucial for PEC and the routes to enhance them. Subsequent discussion will cover thermodynamic cycles and device design rules to extract maximum work and power.

Novel chitosan–celluose nanofiber (CS–CNF) composite hydrogels (modulus ~2 kPa) were prepared to have tunable self-healing properties. The injectability and self-healing ability were significantly enhanced for composite hydrogels. The optimized hydrogel promoted the proliferation and differentiation of neural stem cells in vitro as well as functional recovery (50% enhancement over pristine CS hydrogel) in brain-injured zebrafish. Self-healing properties of CS–CNF hydrogels were positively correlated with regenerative capacities and oxygen metabolism of the hydrogels. A mechanism of multiple-bond interactions may explain the biphasic change of self-healing for these hydrogels. The findings provide some design rationale for self-healing hydrogels with potential biomedical applications.

Surface-grafting polymer brush (SPB) technique can be used to change the inherent physical/chemical properties of materials surface. Practical applications are paid more attention since SPB technique enables to decorate materials with diverse functions. This paper reviews the current grafting strategies to generate polymer brush layer on surface of solid materials with diverse geometric structures/sizes, and then systematically summarizes the recent research advances on application of polymer brushes-modified materials. Correspondingly, some key challenges of SPB technique with considering its real application in future are discussed. The aim to draft this paper is to tell the readers how to engineer functional materials by SPB technique.

A transparent stretchable (TS) capacitive sensor, which can detect pressure (force) and touch inputs distinguishably was fabricated by forming with a TS dielectric layer sandwiched between the upper piezoresistive electrode of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)–ionic liquid composite enabling to distinguish touch and pressure stimuli and the lower TS electrode of metal/indium tin oxide/metal multilayer on a transparent elastomeric substrate with stress-relieving three-dimensional microstructured pattern providing multi-directional stretchability and high pressure sensitivity. The TS sensor array demonstrated a good control of the interaction with a small vehicle as a multi-functional input device for future wearable electronics.

Without the introduction of new functional groups, it is often difficult to alter the properties of a substance, such as by changing it from a non-self-healing to a rapidly self-healing material. In this work, we report that the properties of 2-hydroxyethyl methacrylate and acrylamide (HEMA/AAm) hydrogels can be easily altered from non-self-healing to rapidly self-healing materials by simply tuning the reaction temperature. The stretching capabilities of the hydrogels can be greatly enhanced by up to 30-fold. The hydrogels also exhibit good adhesive performance to various substrates. These results provide valuable insight regarding the design of self-healing hydrogels.