Hydrogen-bonded organic frameworks (HOFs), a new type of porous material following the metal-organic frameworks (MOFs), covalent organic frameworks (COFs),
etc.
, have emerged as one of the promising ...candidates in diverse potential applications. In this highlight, we summarize the key progress on HOF-based materials, in which their design, structures, as well as potential applications will be discussed.
This paper highlights the current key progress on HOF-based materials, including their design, structural characteristics, and applications.
Dual‐atom catalysts (DACs) have emerged as efficient electrocatalysts for CO2 reduction owing to the synergistic effect between the binary metal sites. However, rationally modulating the electronic ...structure of DACs to optimize the catalytic performance remains a great challenge. Herein, we report the electronic structure modulation of three Ni2 DACs (namely, Ni2−N7, Ni2−N5C2 and Ni2−N3C4) by the regulation of the coordination environments around the dual‐atom Ni2 centres. As a result, Ni2−N3C4 exhibits significantly improved electrocatalytic activity for CO2 reduction, not only better than the corresponding single‐atom Ni catalyst (Ni−N2C2), but also higher than Ni2−N7 and Ni2−N5C2 DACs. Density functional theory (DFT) calculations revealed that the high electrocatalytic activity of Ni2−N3C4 for CO2 reduction could be attributed to the electronic structure modulation to the Ni centre and the resulted proper binding energies to COOH* and CO* intermediates.
Three Ni2 dual‐atom catalysts (DACs) with electronic structures tailored by the regulation of the coordination environment of Ni atoms, have been prepared for electrocatalytic CO2 reduction. The optimal Ni2−N3C4 exhibits the highest performance for the reduction of CO2 to CO, highlighting the significance of the electronic structure for electrocatalytic CO2 reduction in DACs.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
2D lamellar materials can offer high surface area and abundant reactive sites, thus showing an appealing prospect in photocatalytic hydrogen evolution. However, it is still difficult to build ...cost‐efficient photocatalytic hydrogen evolution systems based on 2D materials. Herein, an in situ growth method is employed to build 2D/2D heterojunctions, with which 2D Ni‐based metal–organic layers (Ni‐MOLs) are closely grown on 2D porous CdS (P‐CdS) nanosheets, affording traditional P‐CdS/Ni‐MOL heterojunction materials. Impressively, the optimized P‐CdS/Ni‐MOL catalyst exhibits superior photocatalytic hydrogen evolution performance, with an H2 yield of 29.81 mmol g−1 h−1. This value is 7 and 2981 times higher than that of P‐CdS and Ni‐MOLs, respectively, and comparable to those of reported state of the art catalysts. Photocatalytic mechanism studies reveal that the enhanced photocatalytic performance can be attributed to the 2D/2D intimate interface between P‐CdS and Ni‐MOLs, which facilitates the fast charge carriers’ separation and transfer. This work provides a strategy to develop 2D MOL‐based photocatalysts for sustainable energy conversion.
The ultrathin structure and large specific surface area of the P‐CdS/Ni‐MOL composites are of great benefit for exposing more active sites and expanding contact surface area. In such a way, the recombination of photoinduced electrons/holes pairs can be efficiently inhibited. The synergistic effect of the intimate contact between P‐CdS and Ni‐MOLs can significantly enhance the photocatalytic H2 evolution performances.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Metal complexes hybridized with conductive supports are desirable as high-performance catalysts for CO2 electroreduction, while the delicate molecular design to improve both the intrinsic activity of ...complex and the molecule–support interactions still remains challenging. We here employ a conjugation-tuning strategy by comparison between Ni(ii) octabutoxyphthalocyanine and Ni(ii) octabutoxynaphthalocyanine on multi-walled carbon nanotubes (NiPc-B@CNT and NiNc-B@CNT) in aqueous electrocatalytic CO2 reduction, respectively. In contrast to the conventional promotive effects from extended conjugation, the impaired conjugation in the Ni(ii) macrocycles unusually boosts both activity and molecule–support affinity. These merits can be attributed to the favored electronic effects and the higher flexibility of long alkyl chains both arising from the absent extended benzene ring in NiPc-B. Consequently, NiPc-B@CNT exhibits much higher faradaic efficiencies for CO production (FECO ≥ 94% among −0.79 to −1.09 V vs. RHE) than NiNc-B@CNT (FECO < 20%) in an H-cell configuration. The use of a gas-diffusion electrode further raises the electrocatalytic performances of NiPc-B@CNT under 1 atm CO2 (FECO ≈ 100% at −0.15 A cm−2) or simulated flue gas (10% CO2, FECO ≈ 80% at −0.1 A cm−2), respectively.
Metal–organic layers (MOLs), a new class of 2D photocatalysts with abundant readily accessible active sites, have emerged as a new 2D catalysis platform. Most pristine MOLs possess large band gaps ...and merely harvest ultraviolet light, which restricts their application in solar-driven CO2 reduction. If MOLs are combined with visible-light-active semiconductors, it may overcome the shortage and construct efficient CO2 reduction photocatalysts. Herein, a series of 2D/2D TM-MOLs/CN (TM = transition metal; CN = g-C3N4) heterogeneous composites were assembled by an in situ ultrasonic-assisted synthesis method. The resultant Co-MOL/CN(400) exhibited excellent photocatalytic CO2 reduction performance, with a CO formation rate of 539 μmol h−1 g−1 and a selectivity of 79.8%. The proximity of the interfacial contact between Co-MOL and CN facilitates charge carrier separation/transfer from the photosensitizer to catalytic centers, which affords a superior photoactivity performance compared to most MOFs/CN (MOF = metal–organic frameworks) analogous hybrid photocatalysts. This heterogeneous composite thus represents a remarkable stepping stone in 2D/2D assembled multifunctional materials for studying the artificial photocatalytic reduction of CO2 to solar chemicals and fuels.
Abstract
Background
Encephalitis in hand, foot, and mouth disease (HFMD) is a serious threat to children’s health and life. Toll-like receptor 3 (TLR3) is an innate immune-recognition receptor that ...can recognize virus and initiate innate immune responses. Emodin has the effects of anti-inflammatory and regulating immune function, but the mechanism is not very clear.
Methods
Cells and mice were pretreated with coxsackievirus B3m (CVB3) and treated with emodin. The messenger ribonucleic acid (mRNA) and protein levels of TLR3 and downstream molecules were detected by quantitative real-time polymearse chain reaction and western blotting analysis, respectively. TLR3 expression was also downregulated by anti-TLR3 antibody (TLR3Ab) or small interfering RNA (siRNA). Pathological changes were assessed with hematoxylin and eosin staining. Immunohistochemistry was used to examine the expression of TLR3 in brain tissues. The expression of interleukin (IL)-6, nuclear factor (NF)-κB, and interferon (IFN)-β in serum were tested with enzyme-linked immunosorbent assay.
Results
Emodin decreased the mRNA and protein levels of TLR3 and downstream molecules in vitro and in vivo. After downregulating TLR3 using anti-TLR3Ab or siRNA, emodin could still decrease the mRNA and protein levels of TLR3 and downstream molecules. Emodin also displayed notable effects on pathology, TLR3 protein in brain tissues, and expression of IL-6, NF-κB, IFN-β, in serum.
Conclusions
Emodin exerts a protective effect in CVB3-mediated encephalitis in HFMD by inhibiting the TLR3 pathway.
This study indicated that TLR3 pathway is a viable therapeutic target for CVB3-mediated encephalitis in HFMD and certified the efficacy of emodin via inhibiting the TLR3 signaling pathway to alleviate CVB3-mediated encephalitis in HFMD in vitro and in vivo.
A hypoxic microenvironment is a common feature of skin wounds. Our previous study demonstrated that three-dimensional coculture of umbilical cord-derived mesenchymal stem cells (ucMSCs) and ...endothelial cells facilitates cell communication and host integration in skin tissue engineering. Here, we aimed to identify the mechanism by which ucMSCs affect endothelial cells under hypoxic conditions after skin injury. We demonstrate that hypoxia enhances the exosome-mediated paracrine function of ucMSCs, which increases endothelial cell proliferation and migration. In a mouse full-thickness skin injury model, ucMSC-derived exosomes can be taken up by endothelial cells and accelerate wound healing. Hypoxic exosomes lead to a better outcome than normoxic exosomes by promoting proliferation and inhibiting apoptosis. Mechanistically, microRNA-125b (miR-125b) transcription is induced by hypoxia in ucMSCs. After being packaged into hypoxic exosomes and transported to endothelial cells, miR-125b targets and suppresses the expression of tumor protein p53 inducible nuclear protein 1 (TP53INP1) and alleviates hypoxia-induced cell apoptosis. Inhibition of miR-125b-TP53INP1 interaction attenuates the protective effect of hypoxic exosomes. Moreover, artificial agomiR-125b can accelerate wound healing in vivo. Our findings reveal communication between ucMSCs and endothelial cells via exosomal miR-125b/TP53INP1 signaling in the hypoxic microenvironment and present hypoxic exosomes as a promising therapeutic strategy to enhance cutaneous repair.
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Wang and colleagues found that exosomes secreted by ucMSCs under hypoxic conditions enhanced skin wound repair by delivering microRNA-125b into endothelial cells to enhance cell migration and survival by targeting TP53INP1. The authors suggest exosomal-microRNA-125b/TP53INP1 signaling as a novel mechanism that can be exploited for skin repair and tissue engineering.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The newly launched Fengyun-3D (FY-3D) satellite carried a wide-field auroral imager (WAI) that was developed by Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences ...(CIOMP), which will provide a large field of view (FOV), high spatial resolution, and broadband ultraviolet images of the aurora and the ionosphere by imaging the N
LBH bands of emissions. The WAI consists of two identical cameras, each with an FOV of 68° in the along-track direction and 10° in the cross-track direction. The two cameras are tilted relative to each other to cover a fan-shaped field of size 130° × 10°. Each camera consists of an unobstructed four-mirror anastigmatic optical system, a BaF
filter, and a photon-counting imaging detector. The spatial resolution of WAI is ~10 km at the nadir point at a reference height of 110 km above the Earth's surface. The sensitivity is >0.01 counts s
Rayleigh
pixel
(140-180 nm) for both cameras, which is sufficient for mapping the boundaries and the fine structures of the auroral oval during storms/substorms. Based on the tests and calibrations that were conducted prior to launch, the data processing algorithm includes photon signal decoding, geometric distortion correction, photometric correction, flat-field correction, line-of-sight projection and correction, and normalization between the two cameras. Preliminarily processed images are compared with DMSP SSUSI images. The agreement between the images that were captured by two instruments demonstrates that the WAI and the data processing algorithm operate normally and can provide high-quality scientific data for future studies on auroral dynamics.
Due to the flourishing development of vehicle-to-vehicle (V2V) communications and autonomous driving, interference between radar sensing and communication signals becomes a challenging issue. We ...propose a transmit beamforming based spectrum sharing scheme to achieve peaceful coexistence between automotive multiple-input multiple-out (MIMO) radar and communication systems. Our objective is to maximize the signal-to-interference-plus-noise ratio (SINR) of the automotive radar receiver subject to the communication capacity and the transmitted power budget constraints to optimize both the communication covariance matrix and the radar transmit precoder. The formulated optimization problem is non-convex, which is converted to convex by introducing a new slack variable and then solving it using the block coordinate descent, also called alternation optimization, approach. Additionally, the ellipsoid sub-gradient method is then employed to reduce the computational complexity. Simulation results demonstrate that our proposed scheme outperforms the conventional schemes.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Two new degrade cycloartane triterpenoids, named buboditones A, B (1, 2), together with ten known alkaloids, cyclobuxoviridine (3), N-dimethylcycloxobuxovircine (4), cyclovirobuxine C (5), ...cyclovirobuxine A (6), cycloprotobuxine C (7), cycloprotobuxine A (8), cyclobuxoxazine (9), cyclobuxoxazine A (10), buxruguline B (11), irehine (12), were isolated from the leaves and stems of Buxus bodinieri Levl., The structures of compounds 1-2 were elucidated by 1 D and 2 D NMR spectroscopic methods including HSQC, HMBC,
1
H-
1
H COSY, NOESY, as well as HRESIMS spectroscopic analysis.
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