Research articles

We demonstrate intracellular GaN microrod lasers for cell labeling applications. GaN microrods show excellent lasing signals under intracellular conditions with a low lasing threshold (~270 kW/cm²). The lasing spectra from individual intracellular microrods are distinguishable because each GaN microrod has different lasing peak wavelength, mode spacings, and relative PL intensities. This result suggests that GaN microrods can be candidates for cell labeling applications.

Flexible and high-energy-density lithium-sulfur (Li-S) batteries based on all-fibrous sulfur cathodes and separators have structural uniqueness and chemical functionality, exhibit a high gravimetric energy density of 435 Wh kg⁻¹ per cell and excellent reliability in terms of electrochemical performance with a slow decay rate of < 1% per cycle, even under severe mechanical stress/deformation conditions.

The biosynthesis and characterization of a new biodegradable plastic, poly(3-hydroxy-2-methylbutyrate) [P(3H2MB)], which is a member of the bacterial polyhydroxyalkanoate (PHA) family whose members include an α-methylated monomer unit, were investigated. Biosynthesized P(3H2MB) exhibited the highest melting temperature (197 °C) among the biosynthesized PHAs and improved thermal resistance. It also exhibited improved crystallization behavior and mechanical flexibility nearly equal to those of isotactic polypropylene (iPP). The superior physical properties of P(3H2MB) have the potential to open new avenues for the production of high-performance biodegradable plastics for replacing petroleum-based bulk commodity plastics.

In this study, ectomesenchymal stem cells (EMSCs) were modified with the transglutaminase 2 (TG2) genes and tested for their ability to enhance bone regeneration on fibrin scaffold. In vitro analyses revealed that osteogenic differentiation of the EMSCs on the fibrin scaffold was promoted by TG2 expression. Transplanting fibrin scaffold loaded with TG2 gene-modified EMSC into bone defects on rat skull induced significantly faster bone regeneration compared with non-genetically modified EMSC.

Single-particle fluorescence imaging is used to monitor dynamic processes that occur during patterned photopolymerization of liquid-crystalline monomers. Spatial gradient of chemical potential created at the border of bright and dark regions by structured illumination leads to mutual diffusion of polymers and monomers. Fluorescence of single quantum dots doped into the monomers visualizes highly directional mass flow from the illuminated region where the photopolymerization proceeds toward a masked unpolymerized region. The flow-induced orientation of the polymers is subsequently fixed by completion of the polymerization reaction, resulting in a mesoscopic aligned area of the polymer film.

Here, we investigated the details of magnetic skyrmion bubble domain formation by a tilted magnetic field. The in-plane component of the magnetic field serves to reduce the width of the stripe domain. These stripe domains are easily broken and bubble domains are formed. We have demonstrated that the key parameter determining the stripe domain instability is the stripe width, regardless of other material parameters. This bubble generation method can be applicable to generic magnetic films with perpendicular magnetic anisotropy. Our work will facilitate the development of skyrmion-based devices by offering a general method for controlling a large skyrmion population.

Schematic illustration showing our overall approach, studies performed, and envisioned application. Our strategy combines biomechanical and biochemical cues from a mechanically graded biomaterial and GF biopatterning, respectively, to spatially control bone- and tendon-like differentiation. Here, experiments (i) characterized our biomaterial, (ii) investigated the interplay between biomechanical and biochemical cues in vitro, and (iii) assessed the ability of our GF-biopatterned and biphasic biomaterial to spatially control bone- and tendon-like tissue formation in vivo. The envisioned goal of this study is to develop a biomaterial for treating large-to-massive tendon injuries.

We facilely prepared temperature-responsive MXene nanosheet/nanobelt fibers carrying vitamin E with a controllable release ability for wound healing, tissue engineering, and much broader applications.

Toxin proteins can cause physical damage, biochemical degradation and signaling interruption in mammals, leading to disabilities and even death. Most of the current antitoxins are developed against specific toxins. The broad-spectrum antitoxic platforms are still rare. Here, we developed a reactive conjugated polymer, PPV-NHS, which selectively reacted with basic proteins and reduced the activity of these attached proteins. PPV-NHS showed excellent inhibition effect on neurotoxicity and hemolysis caused by α-bungarotoxin and cardiotoxin in vitro and in vivo. This work represents the rational design of functionalized conjugated polymers for anti-virulence therapy with both high efficiency and broad applicability.

Integration and design of existing function units into specialized architectures might show combined and even improved performances of the original components. Here we describe a serial of synthetic antibacterial complexes composed of melittin, a natural antimicrobial peptide, and poly(ethylene glycol), a clinical available agent, as building blocks, which show potent and architecture-modulated antibacterial activity against multidrug-resistant pathogens and decreased cytotoxicity.

In this work, a substrate with dual anisotropy were prepared by combination of 3D printing and magnetic field-induced magnetic nanoparticle assembly. ADSCs cultured on this substrates have significantly higher osteogenic markers expression and more calcium nodules formation was also found, suggesting a stronger tendency of toward osteogenic differentiation of ADSCs. RNA-seq data revealed alteration of that alterations in kinase signaling pathway transduction, cell adhesion and cytoskeletalon reconstruction may account for the elevated osteogenic induction capacity.

A resistive switching device is fabricated using nanostructured nickel cobaltite for high-density data storage and synaptic learning applications. The active switching layer of the device consists of quasi-hexagonal porous nanosheets that enable smooth charge transport. The device shows voltage tunable and forming-free resistive switching effect and non-ideal memristive properties. The rational design of the device helps to show controlled multilevel resistive switching property and thereby switch between three conductive states. The analog switching of the device helps to mimic specific neural network behavior, such as the potentiation, depression and four spike-timing-dependent plasticity rules.

Pressure engineered optical properties as well as presssure induced emergent superconductivity are revealed in II-IV-V₂ semiconductor ZnSiP₂, which demonstrate vivid structure–property relationships. Especially, along with a structural phase transition from tetragonal to cubic phase under compression, ZnSiP₂ evolves from a photovoltaic semiconductor into a superconductor.

The semiconductor SnSe hosts a unique multivalley electronic band structure, offering rich physical phenomena for various applications. Especially its excellent thermoelectric properties are ceaselessly under great attention. By employing pressure-dependent infrared spectroscopy combined with density functional theory calculations, the evolution of the multivalley is mapped under external pressure for different self-dopings. The presented diagram summarizes the findings. In lightly doped SnSe, a phase transition from a semiconductor to a semimetal is observed by increasing the pressure. However, for heavily doped SnSe, altering the Fermi surface, successive Lifshitz transitions take place under pressure, further activating the multivalley physics.

The broken inversion symmetry and time-reversal symmetry along with the large spin–orbit interactions in monolayer MoS₂ make it an ideal candidate for novel valleytronic applications. The present study demonstrates the fabrication of a monolayer MoS₂ field-effect transistor employing [Co/Pt] multilayer electrodes. Integration of PMA electrodes results in very-low Schottky barrier height in MoS_2-based field-effect transistor devices.

we report a field-effect device with a graphene/MoSe₂ channel layer and high-k ion-gel gate dielectric. The device shows a high carrier mobility (~247 cm²/V ∙ s), a high on/off ratio (3.3 × 10⁴), and ambipolar behavior that are controlled by an applied gate voltage. The strong gating effect of the device results in higher external quantum efficiency (EQE) (66.3%), photoresponsivity (285.0 mA/W), and gate-tuning ratio (1.50 μA/V) compared to pristine devices. Therefore, our graphene/MoSe₂ barristor device can be a suitable candidate for use in ambipolar transistors and gate-tunable broad-area photodetectors.

We introduced spintronics-based synapses (spin-S) by utilizing a stripe domain ensuring its highly linear and symmetric weight responses, together with domain-wall motion-based neurons (spin-N) for activation functions. In addition, a crossbar array architecture for the spin-S/N has been proposed and experimentally demonstrated. A simple pattern-classification task was tested using an integrated network of electrically connected spin-S and spin-N to mimic a human brain. Our experimental findings provide a new avenue toward establishing more efficient neural network systems with spintronic devices.

Spin mixing conductance (\(g_r^{ \uparrow \downarrow }\)) and spin interface transparency at the interface of epitaxial Co₂Fe_0.4Mn_0.6Si Heusler alloy and Pt has be studied by inverse spin Hall effect and spin pumping measurements. Highest value of \(g_r^{ \uparrow \downarrow }\) = 1.70 × 10²⁰ m⁻² is observed compared to any other ferromagnetic -Pt heterostructures. Further, a high value of spin interface transparency (~83%) is observed, which makes Co₂Fe_0.4Mn_0.6Si/Pt heterostructure a potential candidate for the development of power efficient spintronics devices.

A hitherto unappreciated shear-strain-mediated magnetoelectric coupling effect with highly tunable ferromagnetic resonance by electric field is demonstrated by using the ferroelastic domain engineering of the ferroelectric substrate. The pure shear strain, instead of magnetic field and electric current, control of Kerr signal with superior stability and nonvolatile behaviors shows promising applications in next-generation lightweight, energy efficient magnetoelectric microwave devices and spintronic devices.

Infrared spectral and spatial imaging configurations were developed based on near-infrared graphene quantum dots with ultranarrow half-width (FWHM = 21 nm). The spectral imaging is obtained without a spectrometer and the spatial imaging exceeds the limits of resolution (superresolved imaging). The superresolved sensing is obtained due to the unique temporal and spectral properties of the quantum dot.