Multifunctional ytterbium oxide buffer for perovskite solar cells.

Perovskite solar cells (PSCs) comprise a solid perovskite absorber sandwiched between several layers of different charge-selective materials, ensuring unidirectional current flow and high voltage output of the devices1,2. A 'buffer material' between the electron-selective layer and the metal electrode in p-type/intrinsic/n-type (p-i-n) PSCs (also known as inverted PSCs) enables electrons to flow from the electron-selective layer to the electrode3-5. Furthermore, it acts as a barrier inhibiting the inter-diffusion of harmful species into or degradation products out of the perovskite absorber6-8. Thus far, evaporable organic molecules9,10 and atomic-layer-deposited metal oxides11,12 have been successful, but each has specific imperfections. Here we report a chemically stable and multifunctional buffer material, ytterbium oxide (YbOx), for p-i-n PSCs by scalable thermal evaporation deposition. We used this YbOx buffer in the p-i-n PSCs with a narrow-bandgap perovskite absorber, yielding a certified power conversion efficiency of more than 25%. We also demonstrate the broad applicability of YbOx in enabling highly efficient PSCs from various types of perovskite absorber layer, delivering state-of-the-art efficiencies of 20.1% for the wide-bandgap perovskite absorber and 22.1% for the mid-bandgap perovskite absorber, respectively. Moreover, when subjected to ISOS-L-3 accelerated ageing, encapsulated devices with YbOx exhibit markedly enhanced device stability.

Differential regulation of phosphorylation, structure, and stability of circadian clock protein FRQ isoforms.

Neurospora crassa is an important model organism for circadian clock research. The Neurospora core circadian component FRQ protein has two isoforms, large FRQ (l-FRQ) and small FRQ (s-FRQ), of which l-FRQ bears an additional N-terminal 99-amino acid fragment. However, how the FRQ isoforms operate differentially in regulating the circadian clock remains elusive. Here, we show l-FRQ and s-FRQ play different roles in regulating the circadian negative feedback loop. Compared to s-FRQ, l-FRQ is less stable and undergoes hypophosphorylation and faster degradation. The phosphorylation of the C-terminal l-FRQ 794-aa fragment was markedly higher than that of s-FRQ, suggesting the l-FRQ N-terminal 99-aa region may regulate the phosphorylation of the entire FRQ protein. Quantitative label-free LC/MS analysis identified several peptides that were differentially phosphorylated between l-FRQ and s-FRQ, which were distributed in FRQ in an interlaced fashion. Furthermore, we identified two novel phosphorylation sites, S765 and T781; mutations S765A and T781A showed no significant effects on conidiation rhythmicity, although T781 conferred FRQ stability. These findings demonstrate that FRQ isoforms play differential roles in the circadian negative feedback loop and undergo different regulations of phosphorylation, structure, and stability. The l-FRQ N-terminal 99-aa region plays an important role in regulating the phosphorylation, stability, conformation, and function of the FRQ protein. As the FRQ circadian clock counterparts in other species also have isoforms or paralogues, these findings will also further our understanding of the underlying regulatory mechanisms of the circadian clock in other organisms based on the high conservation of circadian clocks in eukaryotes.

Design, synthesis, and biological evaluation of multiple F-18 S1PR1 radiotracers in rodent and nonhuman primate.

Here we report our design and synthesis of 28 new fluorine-containing compounds as potential F-18 radiotracers for CNS imaging of sphingosine-1-phosphate receptor 1 (S1PR1), and determination of their in vitro binding potency and selectivity toward S1PR1 over other S1PR subtypes. Nine potent and selective compounds, 7c&d, 9a&c, 12b, 15b, and 18a-c with IC50 values ranging from 0.6-12.3 nM for S1PR1 and weak binding toward S1PR2, 3, 4, and 5, were further 18F-radiolabeled to produce [18F]7c&d, [18F]9a&c, [18F]12b, [18F]15b, and [18F]18a-c. Multi-step F-18 radiochemistry procedures were investigated for radiosynthesis of [18F]7c&d and [18F]9a&c, and the presumed intermediates were synthesized and authenticated by analytic HPLC. We then performed nonhuman primate (NHP) PET brain imaging studies for eight radiotracers: [18F]7c&d, [18F]9a, [18F]12b, [18F]15b, and [18F]18a-c. Three radiotracers, [18F]7c, [18F]7d, and [18F]15b, had high NHP brain uptake with standardized uptake values (SUVs) at 2 h post-injection of 2.42, 2.84, and 2.00, respectively, and good brain retention. Our ex vivo biodistribution study in rats confirmed [18F]7d had a high brain uptake with no in vivo defluorination. Radiometabolic analysis of [18F]7c and [18F]7d in rat plasma and brain samples found that [18F]7c has a more favorable metabolic profile than [18F]7d. However, the trend of increased brain uptake precludes [18F]7c as a suitable PET radiotracer for imaging S1PR1 in the brain. Further structural optmization is warranted to identify a highly S1PR1-specific radiotracer with rapid brain uptake kinetics.

Identification of algicidal monoterpenoids from four chemotypes of Cinnamomum camphora and their algicidal mechanisms on Microcystis aeruginosa.

Cyanobacterial blooms cause serious environmental issues, and plant secondary metabolites are considered as new algaecide for controlling them. Cinnamomum camphora produces a wide spectrum of terpenoids and has 4 main chemotypes, including linalool, camphor, eucalyptol and borneol chemotype. To develop the new cyanobacterial algaecide by using suitable chemotype of Cinnamomum camphora and the main terpenoids, we analyzed the terpenoid composition in the 4 chemotype extracts, evaluated the algicidal effects of the extracts and their typical monoterpenoids on Microcystis aeruginosa, and investigated the algicidal mechanism of the stronger algicidal agents. Among the 4 chemotypes, eucalyptol and borneol chemotype extracts exhibited stronger algicidal effects. In the 4 chemotype extracts, monoterpenoids were the main compounds, of which linalool, camphor, eucalyptol and borneol were the typical components. Among the 4 typical monoterpenoids, eucalyptol and borneol showed stronger algicidal effects, which killed 78.8% and 100% M. aeruginosa cells, respectively, at 1.2 mM after 48 h. In 1.2 mM eucalyptol and borneol treatments, the reactive oxygen species levels markedly increased, and the caspase-3-like activity also raised. With prolonging the treatment time, M. aeruginosa cells gradually shrank and wrinkled, and the cell TUNEL fluorescence intensity and DNA degradation gradually enhanced, indicating that the lethal mechanism is causing apoptosis-like programmed cell death (PCD). Therefore, eucalyptol and borneol chemotype extracts and their typical monoterpenoids have the potential for developing as algaecides to control cyanobacteria through triggering apoptosis-like PCD.

A quick and innovative pipeline for producing chondrocyte-homing peptide-modified extracellular vesicles by three-dimensional dynamic culture of hADSCs spheroids to modulate the fate of remaining ear chondrocytes in the M1 macrophage-infiltrated microenvironment.

BACKGROUND: Extracellular vesicles (EVs) derived from human adipose-derived mesenchymal stem cells (hADSCs) have shown great therapeutic potential in plastic and reconstructive surgery. However, the limited production and functional molecule loading of EVs hinder their clinical translation. Traditional two-dimensional culture of hADSCs results in stemness loss and cellular senescence, which is unfavorable for the production and functional molecule loading of EVs. Recent advances in regenerative medicine advocate for the use of three-dimensional culture of hADSCs to produce EVs, as it more accurately simulates their physiological state. Moreover, the successful application of EVs in tissue engineering relies on the targeted delivery of EVs to cells within biomaterial scaffolds. METHODS AND RESULTS: The hADSCs spheroids and hADSCs gelatin methacrylate (GelMA) microspheres are utilized to produce three-dimensional cultured EVs, corresponding to hADSCs spheroids-EVs and hADSCs microspheres-EVs respectively. hADSCs spheroids-EVs demonstrate excellent production and functional molecule loading compared with hADSCs microspheres-EVs. The upregulation of eight miRNAs (i.e. hsa-miR-486-5p, hsa-miR-423-5p, hsa-miR-92a-3p, hsa-miR-122-5p, hsa-miR-223-3p, hsa-miR-320a, hsa-miR-126-3p, and hsa-miR-25-3p) and the downregulation of hsa-miR-146b-5p within hADSCs spheroids-EVs show the potential of improving the fate of remaining ear chondrocytes and promoting cartilage formation probably through integrated regulatory mechanisms. Additionally, a quick and innovative pipeline is developed for isolating chondrocyte homing peptide-modified EVs (CHP-EVs) from three-dimensional dynamic cultures of hADSCs spheroids. CHP-EVs are produced by genetically fusing a CHP at the N-terminus of the exosomal surface protein LAMP2B. The CHP + LAMP2B-transfected hADSCs spheroids were cultured with wave motion to promote the secretion of CHP-EVs. A harvesting method is used to enable the time-dependent collection of CHP-EVs. The pipeline is easy to set up and quick to use for the isolation of CHP-EVs. Compared with nontagged EVs, CHP-EVs penetrate the biomaterial scaffolds and specifically deliver the therapeutic miRNAs to the remaining ear chondrocytes. Functionally, CHP-EVs show a major effect on promoting cell proliferation, reducing cell apoptosis and enhancing cartilage formation in remaining ear chondrocytes in the M1 macrophage-infiltrated microenvironment. CONCLUSIONS: In summary, an innovative pipeline is developed to obtain CHP-EVs from three-dimensional dynamic culture of hADSCs spheroids. This pipeline can be customized to increase EVs production and functional molecule loading, which meets the requirements for regulating remaining ear chondrocyte fate in the M1 macrophage-infiltrated microenvironment.

[Status and pathways of factors influencing physical activity time among elementary and junior high school students in Beijing].

OBJECTIVE: To describe the current distribution of daily physical activity time among elementary and junior high school students in Beijing, and to analyze the influencing factors and pathways at the individual, family, school and community levels. METHODS: Data were drawn upon from a cross-sectional investigation in Beijing in 2023, and a total of 3 157 elementary and junior high school students were included in the final analysis. Questionnaire was used to collect data on basic characteristics, overall and in-school physical activity time per day, the number of sports mastered, perceived physical activity benefits and barriers scales, perceived family, school, and community physical activity supportive environment scales. Log-binomial regression model was used to analyze the associations between physical activity time and influencing factors, and structural equation modeling was used for the path analysis of the influencing factors. RESULTS: The reported rates of ≥2 hours of overall physical activity per day and ≥1 hour of physical activity in school per day among elementary and junior high school students in Beijing in 2023 were 33.1% and 64.8%, respectively. The associations between the number of sports mastered by students and the reported rate of ≥2 hours of overall physical activity per day showed a typical dose-response relationship (P-trend<0.001). The perceived physical activity benefits-to-barriers ratio (PR=1.24, 95%CI: 1.20-1.28), scores of perceived family, school, and community physical acti-vity supportive environment scales were all positively associated with the reported rate of ≥2 hours of overall physical activity per day (PR=1.51, 95%CI: 1.38-1.66; PR=1.50, 95%CI: 1.37-1.64; PR=1.21, 95%CI: 1.16-1.27). The structural equation modeling showed that the number of sports mastered by the students (ß=0.11, P<0.001), perceived physical activity benefits-to-barriers ratios (ß=0.15, P<0.001), and scores of supportive environment scales consisting of family, school, and community (ß=0.13, P<0.001) were associated with the reported rates of ≥2 hours of overall physical activity per day directly. In addition, the scores of supportive environment scales could indirectly influence the reported rates of ≥2 hours of overall physical activity per day by influencing the number of sports mastered by the students (ß=0.21, P<0.001) and the perceived physical activity benefits-to-barriers ratio (ß=0.56, P<0.001), while the number of sports mastered by the students could indirectly influence the reported rates of ≥2 hours of overall physical activity per day by influencing the perceived physical activity benefits-to-barriers ratios (ß=0.05, P=0.003). The influencing factors and pathways of the reported rates of ≥1 hour of physical activity in school per day were similar with those of the reported rates of ≥2 hours of overall physical activity per day described above. CONCLUSION: The daily physical activity time among elementary and junior high school students in Beijing in 2023 fell short of meeting the national requirement. There was a need to build a supportive environment consisting of family, school, and community for physical activity, to promote the students ' sports skills, to establish the idea of independent physical activity, and to ensure that primary and secondary school students were given one hour of physical activity time every day, both inside and outside the school.

MXene-mediated Interfacial Growth of 2D-2D Heterostructured Nanomaterials as Cathodes for Zn-based Aqueous Batteries.

In this study, we introduce a novel approach for synthesizing two-dimensional (2D) MXene heterostructures featuring a sandwiched and cross-linked network structure. This method addresses the common issue of activity degradation in 2D nanomaterials caused by inevitable aggregation. By utilizing the distinct surface characteristics of MXene, we successfully induced the growth of various 2D nanomaterials on MXene substrates. This strategy effectively mitigates self-stacking defects and augments the exposure of surface areas. In particular, the obtained 2D-2D MXene@NiCo-layered double hydroxide (MH-NiCo) heterostructures exhibit enhanced structural stability, improved chemical reversibility, and heightened charge transfer efficiency, outperforming pure NiCo LDH. The aqueous MH-Ni4Co1//Zn@carbon cloth (MH-Ni4Co1//Zn@CC) battery demonstrates exceptional performance with a remarkable specific capacity of 0.61 mAh cm-2, maintaining 96.6 % capacitance after 2300 cycles. Additionally, it achieves an energy density of 1.047 mWh cm-2 and a power density of 32.899 mW cm-2. This research not only paves the way for new design paradigms in energy-related nanomaterials but also offers invaluable insights for the application and optimization of 2D-2D heterostructures in advanced electrochemical devices.

B-N/B-O Contained Heterocycles as Fusion Locker in Multi-Resonance Frameworks towards Highly-efficient and Stable Ultra-Narrowband Emission.

Fusing condensed aromatics into multi-resonance (MR) frameworks has been an exquisite strategy to modulate the optoelectronic properties, which, however, always sacrifices the small full width at half maxima (FWHM). Herein, we strategically embed B-N/B-O contained heterocycles as fusion locker into classical MR prototypes, which could enlarge the π-extension and alleviate the steric repulsion for an enhanced planar skeleton to suppress the high-frequency stretching/ scissoring vibrations for ultra-narrowband emissions. Sky-blue emitters with extremely small FWHMs of 17-18 nm are thereafter obtained for the targeted emitters, decreased by (1.4-1.9)-fold compared with the prototypes. Benefiting from their high photoluminescence quantum yields of >90 % and fast radiative decay rates of >108  s-1 , one of those emitters shows a high maximum external quantum efficiency of 31.9 % in sensitized devices, which remains 25.8 % at a practical luminance of 1,000 cd m-2 with a small FWHM of merely 19 nm. Notably a long operation half-lifetime of 1,278 h is also recorded for the same device, representing one of the longest lifetimes among sky-blue devices based on MR emitters.

Odorant Receptors for Detecting Flowering Plant Cues Are Functionally Conserved across Moths and Butterflies.

Odorant receptors (ORs) are essential for plant-insect interactions. However, despite the global impacts of Lepidoptera (moths and butterflies) as major herbivores and pollinators, little functional data are available about Lepidoptera ORs involved in plant-volatile detection. Here, we initially characterized the plant-volatile-sensing function(s) of 44 ORs from the cotton bollworm Helicoverpa armigera, and subsequently conducted a large-scale comparative analysis that establishes how most orthologous ORs have functionally diverged among closely related species whereas some rare ORs are functionally conserved. Specifically, our systematic analysis of H. armigera ORs cataloged the wide functional scope of the H. armigera OR repertoire, and also showed that HarmOR42 and its Spodoptera littoralis ortholog are functionally conserved. Pursuing this, we characterized the HarmOR42-orthologous ORs from 11 species across the Glossata suborder and confirmed the HarmOR42 orthologs form a unique OR lineage that has undergone strong purifying selection in Glossata species and whose members are tuned with strong specificity to phenylacetaldehyde, a floral scent component common to most angiosperms. In vivo studies via HarmOR42 knockout support that HarmOR42-related ORs are essential for host-detection by sensing phenylacetaldehyde. Our work also supports that these ORs coevolved with the tube-like proboscis, and has maintained functional stability throughout the long-term coexistence of Lepidoptera with angiosperms. Thus, beyond providing a rich empirical resource for delineating the precise functions of H. armigera ORs, our results enable a comparative analysis of insect ORs that have apparently facilitated and currently sustain the intimate adaptations and ecological interactions among nectar feeding insects and flowering plants.

3D surface reconstruction of transparent objects using laser scanning with a four-layers refinement process.

Acquiring the 3D geometry of objects has been an active research topic, wherein the reconstruction of transparent objects poses a great challenge. In this paper, we present a fully automatic approach for reconstructing the exterior surface of a complex transparent scene. Through scanning a line laser by a galvo-mirror, images of the scene are captured from two viewing directions. Due to the light transmission inside the transparent object, the captured feature points and the calibrated laser plane can produce large number of 3D point candidates with large incorrect points through direct triangulation. Various situations of laser transmission inside the transparent object are analyzed and the reconstructed 3D laser point candidates are classified into two types: first-reflection points and non-first-reflection points. The first-reflection points means the first reflected laser points on the front surface of measured objects. Then, a novel four-layers refinement process is proposed to extract the first-reflection points step by step from the 3D point candidates through optical geometric constraints, including (1) Layer-1 : fake points removed by single camera, (2) Layer-2 : ambiguity points removed by the dual-camera joint constraint, (3) Layer-3 : retrieve the missing first-reflection exterior surface points by fusion and (4) Layer-4 : severe ambiguity points removed by contour-continuity. Besides, a novel calibration model about this imaging system is proposed for 3D point candidates reconstruction through triangulation. Compared with traditional laser scanning method, we pulled in the viewing angle information of the second camera and a novel four-layers refinement process is adopted for reconstruction of transparent objects. Various experiments on real objects demonstrate that proposed method can successfully extract the first-reflection points from the candidates and recover the complex shapes of transparent and semitransparent objects.

Radiosynthesis and evaluation of a fluorine-18 radiotracer [18F]FS1P1 for imaging sphingosine-1-phosphate receptor 1.

Assessment of sphingosine-1-phosphate receptor 1 (S1PR1) expression could be a unique tool to determine the neuroinflammatory status for central nervous system (CNS) disorders. Our preclinical results indicate that PET imaging with [11C]CS1P1 radiotracer can quantitatively measure S1PR1 expression changes in different animal models of inflammatory diseases. Here we developed a multiple step F-18 labeling strategy to synthesize the radiotracer [18F]FS1P1, sharing the same structure with [11C]CS1P1. We explored a wide range of reaction conditions for the nucleophilic radiofluorination starting with the key ortho-nitrobenzaldehyde precursor 10. The tertiary amine additive TMEDA proved crucial to achieve high radiochemical yield of ortho-[18F]fluorobenzaldehyde [18F]12 starting with a small amount of precursor. Based on [18F]12, a further four-step modification was applied in one-pot to generate the target radiotracer [18F]FS1P1 with 30-50% radiochemical yield, >95% chemical and radiochemical purity, and a high molar activity (37-166.5 GBq µmol-1, decay corrected to end of synthesis, EOS). Subsequently, tissue distribution of [18F]FS1P1 in rats showed a high brain uptake (ID% g-1) of 0.48 ± 0.06 at 5 min, and bone uptake of 0.27 ± 0.03, 0.11 ± 0.02 at 5, and 120 min respectively, suggesting no in vivo defluorination. MicroPET studies showed [18F]FS1P1 has high macaque brain uptake with a standard uptake value (SUV) of ∼2.3 at 120 min. Radiometabolite analysis of macaque plasma samples indicated that [18F]FS1P1 has good metabolic stability, and no major radiometabolite confounded PET measurements of S1PR1 in nonhuman primate brain. Overall, [18F]FS1P1 is a promising F-18 S1PR1 radiotracer worthy of further clinical investigation for human use.

Congenital microtia patients: the genetically engineered exosomes released from porous gelatin methacryloyl hydrogel for downstream small RNA profiling, functional modulation of microtia chondrocytes and tissue-engineered ear cartilage regeneration.

BACKGROUND: Mesenchymal stem cells (MSCs) exosomes were previously shown to be effective in articular cartilage repairing. However, whether MSCs exosomes promote mature cartilage formation of microtia chondrocytes and the underlying mechanism of action remains unknown. Additionally, some hurdles, such as the low yield and unsatisfactory therapeutic effects of natural exosomes have emerged when considering the translation of exosomes-therapeutics to clinical practices or industrial production. Herein, we investigated the roles of human adipose-derived stem cells (ADSCs) exosomes in modulating microtia chondrocytes and the underlying mechanism of action. Special attention was also paid to the mass production and functional modification of ADSCs exosomes. RESULTS: We firstly used porous gelatin methacryloyl (Porous Gelma) hydrogel with pores size of 100 to 200 µm for 3D culture of passage 2, 4 and 6 ADSCs (P2, P4 and P6 ADSCs, respectively), and obtained their corresponding exosomes (Exo 2, Exo 4 and Exo 6, respectively). In vitro results showed Exo 2 outperformed both Exo 4 and Exo 6 in enhancing cell proliferation and attenuating apoptosis. However, both Exo 4 and Exo 6 promoted chondrogenesis more than Exo 2 did. Small RNA sequencing results indicated Exo 4 was similar to Exo 6 in small RNA profiles and consistently upregulated PI3K/AKT/mTOR signaling pathway. Notably, we found hsa-miR-23a-3p was highly expressed in Exo 4 and Exo 6 compared to Exo 2, and they modulated microtia chondrocytes by transferring hsa-miR-23a-3p to suppress PTEN expression, and consequently to activate PI3K/AKT/mTOR signaling pathway. Then, we designed genetically engineered exosomes by directly transfecting agomir-23a-3p into parent P4 ADSCs and isolated hsa-miR-23a-3p-rich exosomes for optimizing favorable effects on cell viability and new cartilage formation. Subsequently, we applied the engineered exosomes to in vitro and in vivo tissue-engineered cartilage culture and consistently found that the engineered exosomes could enhance cell proliferation, attenuate apoptosis and promote cartilage regeneration. CONCLUSIONS: Taken together, the porous Gelma hydrogel could be applied to exosomes mass production, and functional modification could be achieved by selecting P4 ADSCs as parent cells and genetically modifying ADSCs. Our engineered exosomes are a promising candidate for tissue-engineered ear cartilage regeneration.

Revision Operation of the Unsatisfactory Microtia Reconstruction With Autologous Costal Cartilage.

BACKGROUND: Revision operation of the unsatisfactory microtia reconstruction is 1 of the most difficult revision operations in plastic surgery. This study discussed the cases about revision operation of the unsatisfactory or failed ear reconstruction using autologous costal cartilage and residual. METHODS: A prospectively maintained database of all consecutive patients who underwent secondary total ear reconstruction from 2013 to 2020 was reviewed. Demographic data and outcomes were assessed. RESULTS: Thirty-six patients with microtia met the inclusion criteria. The age of the patients who underwent secondary reconstruction ranged 6 to 56 years. The follow-up duration was from 1 to 8 years. Primary reconstruction using costal cartilage was performed in 34 cases, and Medpor (porous high-density polyethylene) were used in 2 cases. All 36 cases were treated with costal cartilage as the revision. One-stage revision was performed in 27 cases, including scaffold covered by superficial temporal fascia flap in 9 cases, retroauricular fascia flap in 12 cases and superficial temporal plus retroauricular fascia flap in 5 cases. Nine cases were renovated with expanders by stages, of which 8 cases were covered by retroauricular fascia and 1 case was covered by expanded skin flap. Complications occurred in 2 cases, and 1 patient was not satisfied with the partial scaffold repair. CONCLUSIONS: The effect of revision operation of ear reconstruction with costal cartilage is satisfactory, and different methods of ear reconstruction are indicated in different operation conditions, and the revision surgery requires adequate preoperative evaluation.Level of Evidence: Level IV, therapeutic study.

Accelerating Radiative Decay in Blue Through-Space Charge Transfer Emitters by Minimizing the Face-to-Face Donor-Acceptor Distances.

Thermally activated delayed fluorophors (TADF) featuring through-space charge transfers (TSCT) suffer from low radiative decay rates (kr s), especially for blue emitters. Here, a xanthene bridge is adopted to construct space-confined face-to-face donor-acceptor alignment and minimize their distances down to 2.7-2.8 Å, even shorter than the interlayer distance of graphite and thus strengthening the electronic interactions. The resulting blue TSCT-TADF emitters exhibit peaks around ≈460 nm, photoluminescence quantum yields of >90 %, and kr s of nearly 107  s-1 , almost 2-10 times higher than previously observed values with comparable reverse intersystem crossing rates. The corresponding blue organic light-emitting diodes show maximum external quantum efficiencies of 27.8 % and 34.7 % with Commission Internationale de L'Eclairage y coordinates of 0.29 and 0.15 using those molecules as emitters and sensitizers, respectively.

Fusion of Multi-Resonance Fragment with Conventional Polycyclic Aromatic Hydrocarbon for Nearly BT.2020 Green Emission.

Herein, we report a general strategy for achieving ultra-pure green emissions by suppressing the shoulder peaks in the emission spectra of conventional polycyclic aromatic hydrocarbons (PAHs). Through precise synthetic fusion of multi-resonance (MR) fragments with conventional PAH, extended π-conjugation lengths, increased molecular rigidity, and reduced vibrational frequency could be simultaneously realized. The proof-of-concept emitters exhibited ultra-pure green emissions with dominant peaks at ca. 521 nm, photoluminescence quantum yields that are greater than 99 %, a small full-width-at-half-maximum of 23 nm, and CIE coordinates of (0.16, 0.77). The bottom-emitting organic light-emitting diode (OLED) exhibited a record-high CIEy value of 0.74 and a high maximum external quantum efficiency of 30.5 %. The top-emitting OLED not only achieved a BT.2020 green color (CIE: 0.17, 0.78) for the first time but also showed superior performance among all green OLED devices, with a current efficiency of 220 cd A- .

Mesityl-Functionalized Multi-Resonance Organoboron Delayed Fluorescent Frameworks with Wide-Range Color Tunability for Narrowband OLEDs.

Polycyclo-heteraborin multi-resonance (MR) emitters are promising for high color-purity organic light-emitting diodes (OLEDs). Here, unlike the most common heteroatom ternary-doped (X/B/N) frameworks, a binary-doped (B/N) skeleton is reported with a large energy band for wide-range color tunability. Based on this parent-segment, a "one-pot" catalyst-free borylation method is developed which generates deep blue to pure green MR emitters from readily available starting materials, with peaks at 426-532 nm and full-width-at-half-maxima of 27-38 nm. Impressively, a maximum external quantum efficiency of nearly 40 % is recorded for the corresponding device with Commission Internationale de l'Eclairage coordinates of (0.14, 0.16), representing the state-of-the-art performances. This work presents a new paradigm and synthesis of B/N-doped MR emitters and will motivate the study of other novel frameworks.

Amine-Directed Formation of B-N Bonds for BN-Fused Polycyclic Aromatic Multiple Resonance Emitters with Narrowband Emission.

Despite the remarkable multiple resonance (MR) optoelectronic properties of organic nanographenes with boron and nitrogen atoms disposed para to each other, the synthetic procedures are sophisticated with low yields and the molecular skeletons are limited. Here, a new paradigm of easy-to-access MR emitter is constructed by simplifying the multiborylation through amine-directed formation of B-N bonds while introducing an additional para-positioned nitrogen atom to trigger the MR effect. The proof-of-concept molecules exhibit narrowband emissions at 480 and 490 nm, with full width at half maxima (FWHMs) of only 29 and 34 nm. The devices based on them showed external quantum efficiencies (EQE) of >33.0 %, which remained above 24.0 % even at a high brightness of 5000 cd m-2 . This is the first example of MR emitters with a B-N covalent bond, not only decreasing the synthesis difficulty but also increasing the diversity of MR skeletons for emerging new optoelectronic properties.

Does universal health insurance coverage reduce unmet healthcare needs in China? Evidence from the National Health Service Survey.

BACKGROUND: China has nearly achieved universal health insurance coverage, but considerable unmet healthcare needs still exist. Although this topic has attracted great attention, there have been few studies examining the relationship between universal health insurance coverage and unmet healthcare needs. This study aimed to clarify the impact of universal health insurance coverage and other associated factors on Chinese residents' unmet healthcare needs. METHODS: Data was derived from the fourth, fifth, and sixth National Health Service Survey of Jiangsu Province, which were conducted in 2008, 2013, and 2018, respectively. Descriptive statistics were used to analyze the prevalence of unmet healthcare needs. Binary multivariate logistic regression was used to estimate the association between unmet healthcare needs and universal health insurance coverage, along with other socioeconomic factors. RESULTS: 8.99%, 1.37%, 53.37%, and 13.16% of the respondents in Jiangsu Province reported non-use of outpatient services, inpatient services, physical examinations, and early discharge from hospital, respectively. The trend in the prevalence of unmet healthcare needs showed a decline from 2008 to 2018. Health insurance had a significant reducing effect on non-use of outpatient services, inpatient services, or early discharge from hospital. People having health insurance in 2013 and 2018 were significantly less likely to report unmet healthcare needs compared to those in 2008. The effect of health insurance and its universal coverage on reducing unmet healthcare needs was greater in rural than in urban areas. Other socioeconomic factors, such as age, marital status, educational level, income level, or health status, also significantly affected unmet healthcare needs. CONCLUSIONS: Universal health insurance coverage has significantly reduced Chinese residents' unmet healthcare needs. Policy efforts should pay more attention to the benefits of health insurances in rural areas and optimize urban-rural health resources to promote effective utilization of healthcare.

Preventing forgery attacks in computational ghost imaging or disabling ghost imaging in a "spatiotemporal" scattering medium with weighted multiplicative signals.

The ghost imaging (GI) approach is an intriguing and promising image acquisition technique that can transmit high-quality image information in a scattering environment. In this paper, we focus on two concerns recently emerged in the GI modality: one is the vulnerability to forgery attacks in GI-based optical encryption [Opt. Lett.45, 3917 (2020)OPLEDP0146-959210.1364/OL.392424], and the other is the potential threat of GI to personal privacy regarding non-invasive imaging [Opt. Express28, 17232 (2020)OPEXFF1094-408710.1364/OE.391788]. The core idea is to recommend introducing weighted multiplicative signals [Opt. Express27, 36505 (2019)OPEXFF1094-408710.1364/OE.27.036505] into the computational GI system, whether on the transmitting end or the receiving end. At the transmitting end, the random multiplicative signal can be used as an additional key that can reduce the possibility of forgery attacks, thereby increasing image transmission security. On the receiving end, the introduction of a random multiplicative signal to a spatial scattering medium makes it a "spatiotemporal" scattering medium, whose transmittance changes with time. Further, the spatiotemporal scattering medium can disable direct imaging and GI at the same time with low cost, thereby having great potential in privacy protection in daily lives.

Simultaneously Enhanced Reverse Intersystem Crossing and Radiative Decay in Thermally Activated Delayed Fluorophors with Multiple Through-space Charge Transfers.

Thermally activated delayed fluorescence (TADF) materials with through-space charge transfers (CT) have attracted particularly interest recently. However, the slow reverse intersystem crossing (RISC) and radiative decay always limit their electroluminescence performances. Herein, TADF molecules with ortho-linked multiple donors-acceptor (ortho-Dn -A) motif are developed to create near-degenerate excited states for the reinforcement of spin-orbit coupling. The incorporation of both through-bond and through-space CT enlarges oscillator strength. The optimal ortho-D3 -A compound exhibits a photoluminescence quantum yield of ca. 100 %, a high RISC rate of 2.57×106  s-1 and a high radiative decay rate of 1.00×107  s-1 simultaneously. With this compound as the sensitizer, a TADF-sensitized-fluorescent organic light-emitting diode shows a maximum external quantum efficiency of 31.6 % with an ultrapure green Commission Internationale de L'Eclairage y coordinate value of 0.69.