Maskless photolithography based on ultraviolet micro-LEDs and direct writing method for improving pattern resolution.

Ultraviolet micro-LEDs show great potential as a light source for maskless photolithography. However, there are few reports on micro-LED based maskless photolithography systems, and the studies on the effects of system parameters on exposure patterns are still lacking. Hence, we developed a maskless photolithography system that employs micro-LEDs with peak wavelength 375 nm to produce micrometer-sized exposure patterns in photoresists. We also systematically explored the effects of exposure time and current density of micro-LED on static direct writing patterns, as well as the effects of stage velocity and current pulse width on dynamic direct writing patterns. Furthermore, reducing the size of micro-LED pixels enables obtaining high-resolution exposure patterns, but this approach will bring technical challenges and high costs. Therefore, this paper proposes an oblique direct writing method that, instead of reducing the micro-LED pixel size, improves the pattern resolution by changing the tilt angle of the sample. The experimental results show that the linewidths of the exposed lines decreased by 4.0% and 15.2%, respectively, as the sample tilt angle increased from 0° to 15° and 30°, which confirms the feasibility of the proposed method to improve the pattern resolution. This method is also expected to correct the exposure pattern error caused by optical distortion of the lens in the photolithography system. The system and method reported can be applied in various fields such as PCBs, photovoltaics, solar cells, and MEMS.

Ultrasound-augmented cancer immunotherapy.

Cancer is a growing worldwide health problem with the most broadly studied treatments, in which immunotherapy has made notable advancements in recent years. However, innumerable patients have presented a poor response to immunotherapy and simultaneously experienced immune-related adverse events, with failed therapeutic results and increased mortality rates. Consequently, it is crucial to develop alternate tactics to boost therapeutic effects without producing negative side effects. Ultrasound is considered to possess significant therapeutic potential in the antitumor field because of its inherent characteristics, including cavitation, pyrolysis, and sonoporation. Herein, this timely review presents the comprehensive and systematic research progress of ultrasound-enhanced cancer immunotherapy, focusing on the various ultrasound-related mechanisms and strategies. Moreover, this review summarizes the design and application of current sonosensitizers based on sonodynamic therapy, with an attempt to provide guidance on new directions for future cancer therapy.

From Short Circuit to Completed Circuit: Conductive Hydrogel Facilitating Oral Wound Healing.

The primary challenges posed by oral mucosal diseases are their high incidence and the difficulty in managing symptoms. Inspired by the ability of bioelectricity to activate cells, accelerate metabolism, and enhance immunity, a conductive polyacrylamide/sodium alginate crosslinked hydrogel composite containing reduced graphene oxide (PAA-SA@rGO) is developed. This composite possesses antibacterial, anti-inflammatory, and antioxidant properties, serving as a bridge to turn the "short circuit" of the injured site into a "completed circuit," thereby prompting fibroblasts in proximity to the wound site to secrete growth factors and expedite tissue regeneration. Simultaneously, the PAA-SA@rGO hydrogel effectively seals wounds to form a barrier, exhibits antibacterial and anti-inflammatory properties, and prevents foreign bacterial invasion. As the electric field of the wound is rebuilt and repaired by the PAA-SA@rGO hydrogel, a 5 × 5 mm2 wound in the full-thickness buccal mucosa of rats can be expeditiously mended within mere 7 days. The theoretical calculations indicate that the PAA-SA@rGO hydrogel can aggregate and express SOX2, PITX1, and PITX2 at the wound site, which has a promoting effect on rapid wound healing. Importantly, this PAA-SA@rGO hydrogel has a fast curative effect and only needs to be applied for the first three days, which significantly improves patient satisfaction during treatment.

Carbon Quantum Dots for Long-Term Protection against UV Degradation and Acidification in Paper-Based Relics.

Paper-based cultural relics constitute a significant and invaluable part of human civilization and cultural heritage. However, they are highly vulnerable to environmental factors such as ultraviolet (UV) photodegradation and acidification degradation, posing substantial threats to their long-term preservation. Carbon quantum dots (CQDs), known for their outstanding optical properties, high water solubility, and good safety, offer a promising solution for slowing down UV damage and acidification of paper-based relics during storage and transportation. Herein, we propose a feasible strategy for the simple preparation of CQDs with high dispersion stability, excellent UV absorption, room-temperature phosphorescence, and photostability for the safety protection of paper. Accelerated aging experiments were conducted using UV and dry-heat aging methods on both CQD-protected paper and unprotected paper, respectively, to evaluate the effectiveness of CQD protection. The results demonstrate a slowdown in both the oxidation and acid degradation processes of the protected paper under both UV-aging and dry-heat aging conditions. Notably, CQDs with complex luminescence patterns of both fluorescence and room-temperature phosphorescence also endue them as enhanced optical anticounterfeiting materials for multifunctional paper protection. This research provides a new direction for the protection of paper-based relics with emerging carbon nanomaterials.

Regulating Phase Distribution of Dion-Jacobson Perovskite Colloidal Multiple Quantum Wells Toward Highly Stable Deep-Blue Emission.

Metal halide perovskite colloidal quantum wells (CQWs) hold great promise for modern photonics and optoelectronics. However, current studies focus on Ruddlesden-Popper (R-P) phase perovskite CQWs that contain bilayers of monovalent long-chain alkylamomoniums between the separated perovskite octahedra layers. The bilayers are packed back-to-back via weak van der Waals interaction, resulting in inferior charge carrier transport and easier decomposition of perovskite. This report first creates a new type of perovskite colloidal multiple QWs (CMQWs) in the form of Dion-Jacobson (D-J) structure by introducing an asymmetric diammonium cation. Furthermore, the phase distribution is optimized by the synergistic effect of valeric acid and zwitterionic lecithin, finally achieving pure deep-blue emission at 435 nm with narrow full width at half maximum. The diammonium layer in D-J perovskite CMQWs features extremely short width of only ≈0.6 nm, thereby contributing to more effective charge carrier transport and higher stability. Through the continuous photoluminescence (PL) measurement and corresponding theoretical calculation, the higher stability of D-J perovskite CMQWs than that of R-P structural CMQWs is confirmed. This work reveals the inherent superior stability of D-J structural CMQWs, which opens a new direction for fabricating stable perovskite optoelectronics.

Persistent Charging of CsPbBr3 Perovskite Nanocrystals Confined in Glass Matrix.

Manipulation of persistent charges in semiconductor nanostructure is the key point to obtain quantum bits towards the application of quantum memory and information devices. However, realizing persistent charge storage in semiconductor nano-systems is still very challenge due to the disturbance from crystal defects and environment conditions. Herein, the two-photon persistent charging induced long-lasting afterglow and charged exciton formation are observed in CsPbBr3 perovskite nanocrystals (NCs) confined in glass host with effective lifetime surpassing one second, where the glass inclosure provides effective protection. A method combining the femtosecond and second time-resolved transient absorption spectroscopy is explored to determine the persistent charging possibility of perovskite NCs unambiguously. Meanwhile, with temperature-dependent spectroscopy, the underlying mechanism of this persistent charging is elucidated. A two-channel carrier transfer model is proposed involving athermal quantum tunneling and slower thermal-assisted channel. On this basis, two different information storage devices are demonstrated with the memory time exceeding two hours under low-temperature condition. These results provide a new strategy to realize persistent charging in perovskite NCs and deepen the understanding of the underlying carrier kinetics, which may pave an alternative way towards novel information memory and optical data storage applications.

Network pharmacology to explore the molecular mechanisms of Prunella vulgaris for treating thyroid cancer.

BACKGROUND: Thyroid cancer (TC) is the most common endocrine malignancy that has rapidly increased in global incidence. Prunella vulgaris (PV) has manifested therapeutic effects in patients with TC. We aimed to investigate its molecular mechanisms against TC and provide potential drug targets by using network pharmacology and molecular docking. METHODS: The ingredients of PV were retrieved from Traditional Chinese Medicine Systematic Pharmacology Database. TC-related gene sets were established using the GeneCard and OMIM databases. The establishment of the TC-PV target gene interaction network was accomplished using the STRING database. Cytoscape constructed networks for visualization. Protein-protein interaction, gene ontology and the biological pathway Kyoto encyclopedia of genes and genomes enrichment analyses were performed to discover the potential mechanism. Molecular docking technology was used to analyze the effective compounds from PV for treating TC. RESULTS: 11 active compounds and 192 target genes were screened from PV. 177 potential targets were obtained by intersecting PV and TC gene sets. Network pharmacological analysis showed that the PV active ingredients including Vulgaxanthin-I, quercetin, Morin, Stigmasterol, poriferasterol monoglucoside, Spinasterol, kaempferol, delphinidin, stigmast-7-enol, beta-sitosterol and luteolin showed better correlation with TC target genes such as JUN, AKT1, mitogen-activated protein kinase 1, IL-6 and RELA. The gene ontology and Kyoto encyclopedia of genes and genomes indicated that PV can act by regulating the host defense and response to oxidative stress immune response and several signaling pathways are closely associated with TC, such as the TNF and IL-17. Protein-protein interaction network identified 8 hub genes. The molecular docking was conducted on the most significant gene MYC. Eleven active compounds of PV can enter the active pocket of MYC, namely poriferasterol monoglucoside, stigmasterol, beta-sitosterol, vulgaxanthin-I, spinasterol, stigmast-7-enol, luteolin, delphinidin, morin, quercetin and kaempferol. Further analysis showed that oriferasterol monoglucoside, followed by tigmasterol, were the potential therapeutic compound identified in PV for the treatment of TC. CONCLUSION: The network pharmacological strategy integrates molecular docking to unravel the molecular mechanism of PV. MYC is a promising drug target to reduce oxidative stress damage and potential anti-tumor effect. Oriferasterol monoglucoside and kaempferol were 2 bioactive compounds of PV to treat TC. This provides a basis to understand the mechanism of the anti-TC activity of PV.

Mapping the Identity of Transition Metal Doping and Surface Passivation in Indium Phosphide with Theoretical Calculation.

Understanding the electronic structure of doped InP quantum dots (QDs) is essential to optimize the material for specific optoelectronic applications. However, current synthesis approaches are often tedious and unfavorable for rational tunning. Herein, a combination of experimental and computational studies was conducted to address the doping mechanism and surface passivation of InP QDs. The successful dopant introduction requires low Cu doping concentration and heavy Mn doping, while the Ag doping amount is relatively moderate. This may correspond to the theoretical doping formation energy presented as Cu (-2.52 eV) < Ag (-1.76 eV) < Mn (-0.38 eV). As for surface passivation, inorganic ions and shell-like ZnS are unraveled through simulational investigation. Chloride ion promotes oriented growth toward tetrahedron morphology while nitrate-passivated InP QDs exhibit blurry transmission electron microscope (TEM) morphology. Correspondingly, the binding energy of chloride ion with (111) facet is -2.13 eV significantly lower than those of (110) and (100) facets. Further, the additional Zn 3d bands are more involved in the formation of conduction band, which optimized the Mn-doped InP with a 0.32 eV bandgap. These experimental and model results provide more microscopic details of doped InP, which can motivate theoretically exact control of guest ion stoichiometry with optimized characteristics for electrical devices.

Ultrasound-Targeted Microbubble Destruction-Mediated Cell-Mimetic Nanodrugs for Treating Rheumatoid Arthritis.

Rheumatoid arthritis (RA) is an autoimmune disease that mainly affects joints, and it can lead to disability and damage to vital organs if not diagnosed and treated in time. However, all current therapeutic agents for RA have limitations such as high dose, severe side effects, long-term use, and unsatisfactory therapeutic effects. The long-term use and dose escalation of methotrexate (MTX) may cause mild and severe side effects. To overcome the limitations, it is critical to target drug delivery to the inflamed joints. In this work, we constructed a folic acid-targeted and cell-mimetic nanodrug, MTX-loaded mesoporous silica composite nanoplatform (MMPRF), which can regulate drug release under ultrasound (US) and microbubble (MB) mediation. The targeted delivery and drug therapy were investigated through in vitro RAW264.7 cell experiments and in vivo collagen-induced arthritis animal experiments. The result showed that the targeting ability to the joints of MMPRF was strong and was more significant after US and MB mediation, which can potently reduce joint swelling, bone erosion, and inflammation in joints. This work indicated that the US- and MB-mediated MMPRF not only would be a promising method for synergistic targeted treatment of RA but also may show high potential for serving as a nanomedicine for many other biomedical fields.

A Strategy Inspired by the Cicada Shedding Its Skin for Synthesizing the Natural Material NaFe3 S5 ·2H2 O.

Sulfide minerals hold significant importance in both fundamental science and industrial advancement. However, certain natural sulfide minerals, such as NaFe3 S5 ·2H2 O (NFS), pose great challenges for exploitation and synthesis due to their high susceptibility to oxidation. To date, no successful precedent exists for synthesizing NFS. Here, a novel approach to synthesizing low-cost and pollution-free NFS with high stability using the high-pressure hydrothermal method based solely on knowledge of its chemical formula is presented. Moreover, an innovative strategy inspired by the cicada's molting process to develop unstable natural materials is proposed. The mechanical, thermal, optical, electrochemical, and magnetic properties of the NFS are thoroughly investigated. The storage of lithium, sodium, and potassium ions is primarily concentrated in the gap between (0 0 1) crystal planes. Additionally, as a catalyst for hydrogen evolution reaction (HER) at 10 mA cm-2 , micron-sized NFS exhibits an excellent overpotential of 6.5 mV at 90 °C, surpassing those of reported HER catalysts of similar size. This research bridges the gap in the sulfide mineral family, overcomes limitations of the high-pressure hydrothermal method, and paves the way for future synthesis of natural minerals, lunar minerals, and Martian minerals.

Advanced Composites Inspired by Biological Structures and Functions in Nature: Architecture Design, Strengthening Mechanisms, and Mechanical-Functional Responses.

The natural design and coupling of biological structures are the root of realizing the high strength, toughness, and unique functional properties of biomaterials. Advanced architecture design is applied to many materials, including metal materials, inorganic nonmetallic materials, polymer materials, and so on. To improve the performance of advanced materials, the designed architecture can be enhanced by bionics of biological structure, optimization of structural parameters, and coupling of multiple types of structures. Herein, the progress of structural materials is reviewed, the strengthening mechanisms of different types of structures are highlighted, and the impact of architecture design on the performance of advanced materials is discussed. Architecture design can improve the properties of materials at the micro level, such as mechanical, electrical, and thermal conductivity. The synergistic effect of structure makes traditional materials move toward advanced functional materials, thus enriching the macroproperties of materials. Finally, the challenges and opportunities of structural innovation of advanced materials in improving material properties are discussed.

The direct catalytic synthesis of ultrasmall Cu2O-coordinated carbon nitrides on ceria for multimodal antitumor therapy.

Engineering chem-/sono-/photo-multimodal antitumor therapies has become an efficient strategy to combat malignant tumors. However, the existence of hypoxia in the tumor microenvironment (TME) leads to limited sonodynamic or photodynamic efficiency because O2 is the key reactant during the process of generation of reactive oxygen species (ROS). Here, to design a desirable platform that can simultaneously convert H2O2 in the TME into ROS and O2 for efficient chem-/sono-/photo-multimodal tumor therapies, we have created ultrasmall Cu2O-coordinated carbon nitride on a biocompatible ceria substrate (denoted as Cu2O-CNx@CeO2) via a self-assisted catalytic growth strategy. The chemical and morphological structures, ROS and O2 generation activities, and chemo-/photo-/sono-dynamic specificities of Cu2O-CNx@CeO2 when serving as multifunctional biocatalytic agents were systematically disclosed. The experimental studies validated that Cu2O-CNx@CeO2 presents state-of-the-art peroxidase-like and catalase-like activities. Moreover, the light excitation and ultrasound irradiation were also demonstrated to boost ROS production. The in vitro and in vivo experiments suggest that Cu2O-CNx@CeO2 can efficiently inhibit the growth of malignant melanoma via chem-/sono-/photo-multimodal antitumor ability. We believe that applying these new biocatalysts with dual catalytic activities of producing ROS and O2 will offer a new path for engineering multimodal nanoagents to combat malignant tumors.

Quantitative assessment of muscle properties in polymyositis and dermatomyositis using high-frequency ultrasound and shear wave elastography.

Background: Polymyositis (PM) and dermatomyositis (DM) are two common types of idiopathic inflammatory myopathy and can lead to a poor prognosis and quality of life. We designed this cross-sectional study to investigate the abilities of high-frequency ultrasound (HFUS) and shear wave elastography (SWE) to assess muscle properties in patients with PM and DM and to distinguish healthy muscles from diseased muscles with PM and DM. Methods: A total of 60 patients (26 PM cases and 34 DM cases) and 65 matched healthy volunteers were continuously included in the case and control groups, respectively. For the bilateral deltoid, biceps brachii, rectus femoris, and vastus lateralis, the muscle thickness, echo intensity, and longitudinal shear wave velocity (SWV) of all participants were measured using HFUS and SWE. The intra- and interobserver reliability of SWV measurements of patients with PM and DM and the receiver operating characteristic curve for HFUS and SWE for PM and DM were analyzed. Results: Patients with PM and DM had significantly decreased muscle thickness and increased muscle echo intensity compared to healthy controls (P<0.001). The patients' and healthy participants' deltoid, biceps brachii, rectus femoris, and vastus lateralis thickness was 19.75 and 23.00 mm, 20.45 and 22.80 mm, 18.40 and 20.20 mm, and 20.00 and 22.80 mm, respectively. Except for the biceps brachii, the mean SWV in the longitudinal orientation in patients with PM and DM significantly decreased (P<0.01). The mean SWV of the patients' and healthy participants' deltoid, rectus femoris, and vastus lateralis was 2.47 and 2.57 m/s, 1.73 and 1.87 m/s, and 1.57 and 1.77 m/s, respectively. Excellent intra- and interobserver reliability of SWV measurements on the deltoid and rectus femoris of PM and DM patients were found (intraclass correlation coefficient >0.95; P<0.001). The diagnostic performance of echo intensity in lower-extremity proximal muscles for PM and DM was excellent [area under the curve (AUC) >0.9]. The thickness of most muscles displayed moderate diagnostic performance (the AUC ranged from 0.700 to 0.775). The SWV of the vastus lateralis showed a stable performance (AUC =0.741). The combined diagnostic performance of echo intensity and thickness and the combined diagnostic performance of the 3 indicators were relatively high (the AUC ranged from 0.871 to 0.936 and from 0.898 to 0.938, respectively). Muscle thickness and echo intensity showed statistical differences in different disease stages of PM and DM (P'<0.01). Conclusions: HFUS and SWE may serve as imaging biomarkers for the diagnosis of PM and DM by detecting abnormal muscle thinning, enhanced muscle echo intensity, and reduced muscle SWV.

Facile synthesis of red-emissive carbon dots with theoretical understanding for cellular imaging.

Recently, red emissive carbon dots (R-CDs) have drawn widespread attention on account of their desirable fluorescence properties and good biocompatibility. Despite great efforts, facile synthesis of R-CDs for cellular imaging remains challenging and the fluorescence mechanism of R-CDs is still elusive. Herein, p-phenylenediamine-derived R-CDs with excitation-independency were successfully obtained through a facile solvothermal approach together with proportional precipitation. The fluorescent solvatochromism of R-CDs is realized, while high polarity leads to higher degree of dipole interaction between R-CDs and different solvents, favoring for emissive red-shift. Furthermore, density functional theory is adopted to explore the optical and electronic characteristics of some polycyclic aromatic molecules. Among different configurations, pyridine nitrogen and carbonyl bonds could relatively increase the charge density and significantly narrow the band gap, which can provide a crucial theoretical basis for the precise preparation of R-CDs. Moreover, R-CDs possess favorable cellular imaging ability, which indicates their potential for a promising candidate as fluorescence probes in bioimaging.

Ultrasound-augmented anti-inflammatory exosomes for targeted therapy in rheumatoid arthritis.

Rheumatoid arthritis (RA), one of the systemic autoimmune diseases, features dysregulated inflammation that can eventually lead to multi-joint destruction and deformity. Although current clinical RA treatment agents including non-steroidal anti-inflammatory drugs, disease-modifying antirheumatic drugs, and biological agents can alleviate symptoms, there can be long-term drug dependence and considerable side effects. To promote the course of RA from inflammation to resolution and ultimately terminate the vicious cycle of recrudescence, it is important to regulate the pro-/anti-inflammatory abilities of macrophages for constructing an immunosuppressive or anti-inflammatory microenvironment. Macrophage-derived exosomes can be homed or targeted to inflammatory tissues or cells; however, the insufficient anti-inflammatory abilities and intrinsic off-target effects of these exosomes often result in unsatisfactory treatment effects, which remains a challenge in the treatment of RA. Here, we proposed a novel kind of inherent anti-inflammatory exosome (AI-Exo), which was prepared via integrating RAW264.7 macrophage-derived exosomes and a powerful anti-inflammatory immune modulator interleukin-10 by an electroporation method. Then, non-invasive ultrasound was used to increase the permeability of blood vessels and augment the targeted accumulation of AI-Exo to inflammatory tissues, which could promote macrophage polarization to M2 phenotypes, relieve inflammation symptoms, stimulate resolution, and accelerate tissue repair against collagen-induced arthritis. This work intensely supports that ultrasound-augmented AI-Exo has significant targeted anti-inflammatory therapeutic effects, and the combined mechanism of anti-inflammation and pro-resolution gives unique insights into the treatment of not only RA but also other inflammatory diseases, which provides an effective strategy and a promising prospect for future wider biomedical applications and clinical transformations.

Evaluation of connective tissue disease-related interstitial lung disease using ultrasound elastography: a preliminary study.

Background: Interstitial lung disease (ILD) is a common pulmonary complication of connective tissue disease (CTD), which can lead to shortened survival. This article explores the ability of shear wave elastography (SWE) to assess lung surface elastic properties and to distinguish healthy lungs from diseased lungs with connective tissue disease-related interstitial lung disease (CTD-ILD). We aimed to determine whether SWE can be used to assess the severity of CTD-ILD. Methods: A total of 65 CTD-ILD patients and 60 healthy volunteers were included for the case group and the control group, respectively. All participants underwent lung ultrasound (count of B-line and measurement of pleural line thickness) and SWE [measurement of Young's modulus (Emean) and shear wave velocity (SMV) (Cmean)] examinations at 50 lung sites. All participants also underwent an examination with high-resolution computed tomography (HRCT) and a pulmonary function test (PFT). For SWE assessment, the Q-box was set to its minimum size (1 mm) and manually placed on the pleural line, rather than inside the lung, to measure the stiffness of the lung surface. The intra- and inter-reliability of SWE measurements of healthy controls (HC), the receiver operating characteristic (ROC) curve for SWE for CTD-ILD, and correlations between different assessment methods were analyzed. Results: Excellent intra- and inter-reliability of SWE measurements on the mid-anterior lung site of HCs (correlation coefficient >0.97; P<0.01) were found. The results of the lung ultrasound of case group participants were significantly higher than those of HCs at each site (P<0.001). The SWE results revealed a significant increase in both Emean and Cmean in CTD-ILD patients (P<0.001) compared with HCs at certain sites (P<0.001). The areas under the curve (AUC) of Emean and Cmean for CTD-ILD were 0.646 and 0.647 (P<0.05), respectively, and the cutoff values for Emean and Cmean to distinguish CTD-ILD from healthy lungs were 15.81 kPa and 2.31 m/s, respectively. There was no significant correlation between the SWE measured values and the number of B-lines, or the HRCT and PFT results, respectively (P>0.05). Conclusions: As a noninvasive ultrasound elastography (UE) technique, SWE may provide a novel method to differentiate CTD-ILD-affected lungs and healthy lungs. It is a reliable way to measure the stiffness of a healthy lung surface in the supine position. However, the ability of SWE to evaluate the severity of CTD-ILD may be limited.

Synergistic Effect of Halogen Ions and Shelling Temperature on Anion Exchange Induced Interfacial Restructuring for Highly Efficient Blue Emissive InP/ZnS Quantum Dots.

InP quantum dots (QDs) have attracted much attention owing to their nontoxic properties and shown great potential in optoelectronic applications. Due to the surface defects and lattice mismatch, the interfacial structure of InP/ZnS QDs plays a significant role in their performance. Herein, the formation of In-S and Sx -In-P1-x interlayers through anion exchange at the shell-growth stage is revealed. More importantly, it is proposed that the composition of interface is dependent on the synergistic effect of halogen ions and shelling temperature. High shelling temperature contributes to the optical performance improvement resulting from the formation of interlayers, besides the thicker ZnS shell. Moreover, the effect relates to the halogen ions where I- presents more obvious enhancement than Br- and Cl- , owing to their different ability to coordinate with In dangling bonds, which are inclined to form In-S and Sx -In-P1-x bonds. Further, the anion exchange under I- -rich environment causes a blue-shift of emission wavelength with shelling temperature increasing, unobserved in a Cl- - or Br- -rich environment. It contributes to the preparation of highly efficient blue emissive InP/ZnS QDs with emission wavelength of 473 nm, photoluminescence quantum yield of ≈50% and full width at half maximum of 47 nm.

White-Light GaN-µLEDs Employing Green/Red Perovskite Quantum Dots as Color Converters for Visible Light Communication.

GaN-based µLEDs with superior properties have enabled outstanding achievements in emerging micro-display, high-quality illumination, and communication applications, especially white-light visible light communication (WL-VLC). WL-VLC systems can simultaneously provide white-light solid-state lighting (SSL) while realizing high-speed wireless optical communication. However, the bandwidth of conventional white-light LEDs is limited by the long-lifetime yellow yttrium aluminum garnet (YAG) phosphor, which restricts the available communication performance. In this paper, white-light GaN-µLEDs combining blue InGaN-µLEDs with green/red perovskite quantum dots (PQDs) are proposed and experimentally demonstrated. Green PQDs (G-PQDs) and red PQDs (R-PQDs) with narrow emission spectrum and short fluorescence lifetime as color converters instead of the conventional slow-response YAG phosphor are mixed with high-bandwidth blue InGaN-µLEDs to generate white light. The communication and illumination performances of the WL-VLC system based on the white-light GaN-based µLEDs are systematically investigated. The VLC properties of monochromatic light (green/red) from G-PQDs or R-PQDs are studied in order to optimize the performance of the white light. The modulation bandwidths of blue InGaN-µLEDs, G-PQDs, and R-PQDs are up to 162 MHz, 64 MHz, and 90 MHz respectively. Furthermore, the white-light bandwidth of 57.5 MHz and the Commission Internationale de L'Eclairage (CIE) of (0.3327, 0.3114) for the WL-VLC system are achieved successfully. These results demonstrate the great potential and the direction of the white-light GaN-µLEDs with PQDs as color converters to be applied for VLC and SSL simultaneously. Meanwhile, these results contribute to the implementation of full-color micro-displays based on µLEDs with high-quality PQDs as color-conversion materials.

Simple Structural Descriptor Obtained from Symbolic Classification for Predicting the Oxygen Vacancy Defect Formation of Perovskites.

Symbolic classification is an approach of interpretable machine learning for building mathematical formulas that fit certain data sets. In this work, symbolic classification is used to establish the relationship between oxygen vacancy defect formation energy and structural features. We find a structural descriptor na(ra/Ena - rb), where na is the valence of the a-site ion, ra is the radius of the a-site ion, Ena is the electronegativity of the a-site ion, and rb is the radius of the b-site ion. It accelerates the screening of defect-free oxide perovskites in advance of density functional theory (DFT) calculations and experimental characterization. Our results demonstrate the potential of symbolic classification for accelerating the data-driven design and discovery of materials with improved properties.

Modulating Electron Transfer in Vanadium-Based Artificial Enzymes for Enhanced ROS-Catalysis and Disinfection.

Nanomaterials-based artificial enzymes (AEs) have flourished for more than a decade. However, it is still challenging to further enhance their biocatalytic performances due to the limited strategies to tune the electronic structures of active centers. Here, a new path is reported for the de novo design of the d electrons of active centers by modulating the electron transfer in vanadium-based AEs (VOx -AE) via a unique Zn-O-V bridge for efficient reactive oxygen species (ROS)-catalysis. Benefiting from the electron transfer from Zn to V, the V site in VOx -AE exhibits a lower valence state than that in V2 O5 , which results in charge-filled V-dyz orbital near the Fermi level to interfere with the formation of sigma bonds between the V- d z 2 and O-pz orbitals in H2 O2 . The VOx -AE exhibits a twofold Vmax and threefold turnover number than V2 O5 when catalyzing H2 O2 . Meanwhile, the VOx -AE shows enhanced catalytic eradication of drug-resistant bacteria and achieves comparable wound-treatment indexes to vancomycin. This modulating charge-filling of d electrons provides a new direction for the de novo design of nanomaterials-based AEs and deepens the understanding of ROS-catalysis.