Lei Chen

Spinal cord injury (SCI) often results in permanent motor dysfunction, and no approved therapy effectively promotes nerve regeneration. We show that engineered extracellular vesicles (EVs) from photobiomodulation (PBM)‐treated microglia, delivering UFL1 (the sole E3 ligase of the UFMylation system), significantly enhance neural repair after SCI. PBM (850 nm, 2.0 J/cm ² ) promoted microglial M2 polarization and suppressed M1. We isolated PBM‐EVs and identified UFL1 as the key effector via proteomic analysis. Mechanistically, UFL1 competes with MDM2 for p53 binding, inhibiting p53 ubiquitination and degradation, thus stabilizing p53 and activating its signaling. In vitro, PBM‐EV‐delivered UFL1 protected neural stem cells from inflammation‐induced apoptosis and promoted neuronal differentiation; these effects were markedly attenuated by UFL1 knockdown or p53 inhibition. In a rat SCI model, PBM‐EVs delivering UFL1 significantly improved the local immune microenvironment, promoted M2 microglial polarization, reduced glial scar formation, and enhanced axonal regeneration and hindlimb motor recovery. Pharmacological p53 inhibition with PFT‐α or UFL1 knockdown in donor EVs substantially diminished these therapeutic effects in vivo, confirming the central role of the UFL1/p53 axis. Overall, PBM‐EVs deliver UFL1 to activate p53 signaling, synergistically regulating immunity and neural differentiation to promote functional recovery, highlighting the UFL1/p53 axis as a therapeutic target for SCI.

In this study, a new near-infrared phosphor, Sr8MgSc(PO4)7:Cr3+, was synthesized via a high-temperature solid-state reaction. The optimal synthesis conditions were determined to be 1300 °C for 9 hours. Structure characterization confirms that Cr3+ preferentially occupies the Sc3+ sites, with an optimal doping concentration of 5% mol. Upon excitation at 470 nm, the phosphor exhibited broadband emission in the range of 700-1100 nm with a peak at 840 nm.The luminescence intensity at 100 °C decreases to 17.2% of its room-temperature value. Driven at 100 mA, the LED device exhibited an output power of 0.81 mW and an optoelectronic conversion efficiency of 0.30%, with an emission peak at 860 nm. Interestingly, the electron thermal vibration peaks were obviously distinguished from excitation spectra, which must be induced by the heavy PO43- ligand. This discovery provides an important reference for future design of new phosphors with Cr³⁺ as activator.

Green emission is of particular importance in persistent luminescence (PersL) materials due to its high sensitivity to the human eye and broad application potential. Since the 1990s, the commercial material SrAl2O4:Eu2+, Dy3+ has dominated this field for nearly three decades, owing to its high brightness and long afterglow duration. However, given the extraction difficulties and low recyclability of rare-earth ions, the development of efficient rare-earth-free alternatives, especially in the green spectral region, remains a critical challenge. In this work, we present a green-emitting PersL material, Ba0.4Sr1.6Ga4O8:Cu2+, shows strong emission at 533 nm and an exceptional PersL duration of 78 h under ultraviolet excitation, comparable to the performance of a SrAl2O4:Eu2+,Dy3+ reference sample synthesized following an optimized literature protocol of 51 h. A combination of experimental characterization and theoretical calculations indicates that the ultralong PersL arises from the synergy between O2–→Cu2+ charge transfer luminescence and intrinsic hole traps largely related to gallium vacancies (VGa), continuous distribution of trap states within the forbidden band with depth from about 0.6 to 1.1 eV. This study demonstrates the comparable potential of Cu2+ ions to rare-earth ions for long-persistence luminescence, paving the way for their various applications in fields such as information storage, anticounterfeiting, and so on. Furthermore, it provides a fresh perspective on the design principles for Cu2+-activated phosphors.

The practical implementation of two‐dimensional (2D) transistors is fundamentally limited by the lack of gate dielectrics that can simultaneously deliver a high dielectric constant, a wide bandgap, strong breakdown strength, and long‐term environmental stability‐an often‐overlooked yet critical requirement for reliable device integration. Here, we report 2D single‐crystalline TbOCl nanosheets as gate dielectrics that uniquely reconcile these competing demands. TbOCl exhibits a high dielectric constant (12.5), an ultrawide bandgap (∼6.6 eV), and a high breakdown field (11.9 MV cm ⁻¹ ). MoS ₂ field‐effect transistors (FETs) gated by TbOCl exhibit excellent electrostatic control, yielding a near‐ideal subthreshold swing of 72 mV dec ⁻¹ , a small hysteresis of only 8 mV, and an ultra‐low gate leakage current of ∼10 ⁻¹³ A. Notably, TbOCl‐based devices maintain ultrastable electrical performance after more than 9 months of ambient storage with negligible performance degradation. The superior stability originates from an intrinsic dual‐antioxidation mechanism that effectively suppresses oxidative degradation of the dielectric. Furthermore, logic inverters fabricated with TbOCl gate dielectrics exhibit fast switching behavior, with rise and fall times of 80 and 16 µs, respectively. Together, these results establish TbOCl as a stable, high‐performance 2D dielectric platform, offering a viable pathway toward reliable 2D electronic devices.

Phosphor-converted near-infrared (NIR) light-emitting diodes (LEDs) have garnered substantial attention in recent research due to their potential applications in night vision monitoring, plant growth, anti-counterfeiting, safety testing, bioimaging, and photomedicine. Chromium(III) (Cr3+) stands out as one of the most promising activators, as it can efficiently match the blue emission of LED chips to produce NIR light with tunable emission wavelengths and bandwidths. However, luminescence aging of Cr3+-activated phosphors remains a critical challenge hindering their industrialization and practical deployment. In this study, the luminescent properties of Cr3+-activated phosphors, synthesized with varying Cr3+ doping concentrations, synthesis temperatures, and reaction times, were systematically investigated following aging periods ranging from 19 to 83 months. The results in combining with a comprehensive literature analysis reveal that nearly all Cr3+-activated NIR phosphors undergo luminescence aging to some degree, which is characterized by decreased luminescence intensity, emission wavelength shifts, spectral splitting, or spectral shape distortion. Finally, several strategies are proposed to mitigate the luminescence aging of Cr3+-activated phosphors, aiming to advance the development of long-term stable NIR light sources.

Salicylic acid (SA), a widely distributed environmental pollutant, requires accurate detection for effective water quality monitoring and ecological protection. In this work, we developed a highly sensitive fluorescent sensor by encapsulating boron‐doped graphene quantum dots (B‐GQDs) within amino‐functionalized lanthanum‐based metal‐organic frameworks (NH ₂ ‐La‐MOFs). Upon 365 nm excitation, the composite exhibits strong blue emission peaking at 430 nm, which is significantly quenched and red‐shifted to 560 nm as the SA concentration increases to 50 μM. This spectral shift is accompanied by a distinct color change visible to the naked eye, enabling intuitive visual detection. The quenching mechanism is attributed to static interactions and a reduction in the excited‐state bandgap. Spherical aberration‐corrected scanning transmission electron microscopy (Cs‐STEM) confirms the uniform distribution of B‐GQDs within the NH ₂ ‐La‐MOFs matrix. Density functional theory (DFT) calculations reveal that hydrogen bonding and π–π stacking greatly enhance SA adsorption, which is consistent with the observed Zeta potential shift from −2.90 mV to −17.6 mV, indicating enhanced surface charge density and improved SA binding affinity. Selectivity tests demonstrate that the quenching efficiency (I ₅₀ /I ₄₀ ≈ 0.15) remains stable even in the presence of 10 μM common interfering species such as Na ⁺ , K ⁺ , Mg ²⁺ , glucose, and alanine, indicating excellent anti‐interference performance. By adopting the strategy of metal‐organic frameworks coupled with boron‐doped graphene quantum dots, this work provides a robust, portable, paper‐based, flexible fluorescent sensor for efficient visual detection of salicylic acid in environmental applications.