China's high-speed rail (HSR) construction provides an ideal 'quasi-natural experiment' in which regional issues are investigated. This study explores how HSR affects innovation efficiency and ...explores the mediating effect of urban form. Based on panel data comprising 280 cities in China from 2006 to 2016, this study uses a time-varying difference-in-differences method to analyze whether HSR affects regional innovation, and it explores the mediating effect of urban form. The results show the following. (1) HSR significantly promotes regional innovation. The parallel trend test shows that the treatment group and the control group have the same trend before HSR construction. (2) Knowledge spillovers are important manifestations through which HSR promotes regional innovation. HSR can significantly improve the level of total factor productivity and human capital. (3) Urban form mediates the impact of HSR on regional innovation significantly, which varies across the different indexes of different urban forms.
Nanographene with a Nitrogen‐Doped Cavity Wang, Fei‐Fan; Wang, Yu‐Xiang; Wu, Qiong ...
Angewandte Chemie International Edition,
January 8, 2024, Volume:
63, Issue:
2
Journal Article
Peer reviewed
Nitrogen‐doped cavities are pervasive in graphenic materials, and represent key sites for catalytic and electrochemical activity. However, their structures are generally heterogeneous. In this study, ...we present the synthesis of a well‐defined molecular cutout of graphene featuring N‐doped cavity. The graphitization of a macrocyclic pyridinic precursor was achieved through photochemical cyclodehydrochlorination. In comparison to its counterpart with pyridinic nitrogen at the edges, the pyridinic nitrogen atoms in this nanographene cavity exhibit significantly reduced basicity and selective binding to Ag+ ion. Analysis of the protonation and coordination equilibria revealed that the tri‐N‐doped cavity binds three protons, but only one Ag+ ion. These distinct protonation and coordination behaviors clearly illustrate the space confinement effect imparted by the cavities.
A nanographene with a tri‐N‐doped cavity was synthesized by photo‐induced cyclization. In comparison with nitrogen‐doping at the edge, this tri‐N‐doped holey nanographene exhibited markedly reduced basicity and selective affinity toward Ag+. This nanographene with a N‐doped cavity provides a precise model for understanding the binding in the nano‐confined defects of graphenic materials.
Selective autophagy mediates specific degradation of unwanted cytoplasmic components to maintain cellular homeostasis. The suppressor of gene silencing 3 (SGS3) and RNA‐dependent RNA polymerase 6 ...(RDR6)‐formed bodies (SGS3/RDR6 bodies) are essential for siRNA amplification in planta. However, whether autophagy receptors regulate selective turnover of SGS3/RDR6 bodies is unknown. By analyzing the transcriptomic response to virus infection in Arabidopsis, we identified a virus‐induced small peptide 1 (VISP1) composed of 71 amino acids, which harbor a ubiquitin‐interacting motif that mediates interaction with autophagy‐related protein 8. Overexpression of VISP1 induced selective autophagy and compromised antiviral immunity by inhibiting SGS3/RDR6‐dependent viral siRNA amplification, whereas visp1 mutants exhibited opposite effects. Biochemistry assays demonstrate that VISP1 interacted with SGS3 and mediated autophagic degradation of SGS3/RDR6 bodies. Further analyses revealed that overexpression of VISP1, mimicking the sgs3 mutant, impaired biogenesis of endogenous trans‐acting siRNAs and up‐regulated their targets. Collectively, we propose that VISP1 is a small peptide receptor functioning in the crosstalk between selective autophagy and RNA silencing.
Synopsis
Genomic analyses have predicted numerous potentially expressed small peptides in plants, but their functions remain largely unknown. Here, a virus‐induced peptide is identified as a new autophagy receptor triggering degradation of SGS3/RDR6‐bodies and negatively regulating siRNA amplification.
VISP1 is a novel virus‐induced small peptide composed of 71 amino acids in Arabidopsis.
VISP1 harbors a ubiquitin‐interacting motif (UIM), which mediates the interaction with ATG8.
VISP1 serves as a new autophagy receptor and triggers autophagic degradation of SGS3/RDR6‐bodies.
VISP1 negatively regulates SGS3/RDR6‐dependent siRNA amplification.
VISP1, a small virus‐induced peptide, functions as an autophagy receptor to negatively regulate SGS3/RDR6‐dependent siRNA amplification in plants.
Based on the improved Tapio decoupling model and geographic information system spatial analysis technology, this paper studied the spatial and temporal pattern evolution law of the decoupling ...relationship between innovation capability and resource consumption in 283 cities in China. The non-residual complete decomposition model was used to decompose the rebound effect of resource consumption in China's urban innovation development. We found (1) during the study period, innovation capability and resource consumption in Chinese cities showed a weak decoupling state. (2) Regions with significant decoupling showed a trend of spatial agglomeration, and the gap in the degree of urban decoupling gradually narrowed. (3) The increase in urban population growth and innovation intensity in China have a positive pull effect on resource consumption. The improvement in resource efficiency has an inhibitory effect on resource consumption, but this inhibition is less than the effect of population scale and innovation intensity on resource consumption.
Summary
CD100 is an immune semaphorin constitutively expressed on T‐cells. Matrix metalloproteinase (MMP) is an important mediator of membrane‐bound CD100 (mCD100) cleavage to generate soluble CD100 ...(sCD100), which has immunoregulatory activity in immune cell responses. The aim of the study was to investigate the level and role of sCD100 and mCD100 in modulating CD8+ T‐cell function in non‐small cell lung cancer (NSCLC). sCD100 and MMP‐14 levels in the serum and bronchoalveolar lavage fluid (BALF), and mCD100 expression on peripheral and lung‐resident CD8+ T‐cells were analysed in NSCLC patients. The ability to induce sCD100 and the effect of MMP‐14 on mCD100 shedding for the regulation of non‐cytolytic and cytolytic functions of CD8+ T‐cells were also analysed in direct and indirect contact co‐culture systems. NSCLC patients had lower serum sCD100 and higher mCD100 levels on CD8+ T‐cells compared with healthy controls. BALF from the tumour site also had decreased sCD100 and increased mCD100 on CD8+ T‐cells compared with the non‐tumour site. Recombinant CD100 stimulation enhanced non‐cytolytic and cytolytic functions of CD8+ T‐cells from NSCLC patients, whereas blockade of CD100 receptor CD72 attenuated CD8+ T‐cell activity. NSCLC patients had lower MMP‐14 in the serum and in BALF from the tumour site. Recombinant MMP‐14 mediated mCD100 shedding from CD8+ T‐cell membrane, and led to promotion of CD8+ T‐cell response in NSCLC patients. Overall, decreased MMP‐14 resulted in insufficient CD100 shedding, leading to suppression of peripheral and lung‐resident CD8+ T‐cell activity in NSCLC.
Non‐small cell lung cancer patients had lower serum sCD100 and MMP‐14, while higher mCD100 on CD8+ T‐cells. MMP‐14‐CD100 signalling pathway enhanced the non‐cytolytic and cytolytic functions of CD8+ T‐cells through CD72. Decreased MMP‐14 mediated insufficient CD100 shedding, leading to suppression of peripheral and lung‐resident CD8+ T‐cell activity in NSCLC.
The advancement of technological innovations may facilitate the coordinated development of the economy and ecological environment (EGE); however, few studies have noted the role of innovation ...efficiency (INEF) as a bridge between economic development and EGE. To fill in this gap, this paper adopts DMSP/OLS nighttime light data to measure the level of economic development and the improved data envelopment analysis model to measure INEF, establishing an index system to quantify EGE. Then we propose the panel threshold-mediating (PTM) model that combines the panel threshold model and the mediating effect model. On these bases, considering INEF as a mediator, we use this novel PTM model to empirically test the nonlinear relationship between economic development and EGE in 283 Chinese cities from 2003 to 2018. The results indicate that (1) while economic development can improve EGE, its positive impact on EGE differs with different INEF thresholds. A higher INEF threshold indicates a stronger positive effect of economic development on EGE. (2) For the entire sample, the mediating effect of INEF between economic development and EGE is not significant. However, after applying the PTM model, we found that the mediating effect of INEF was concealed by the sample population. (3) When INEF is lower than 0.2381, its complete mediating effect is verified. When INEF is higher than 0.2381, its mediating effect is not significant. On the contrary, economic development directly improves EGE. (4) Industrial agglomeration, the scale of government expenditure, residents’ education level, degree of opening up, and transport infrastructure are all conducive to EGE. These findings can help cities at different INEF levels to achieve coordinated development of economy and EGE.
As obligate intracellular phytopathogens, plant viruses must take advantage of hosts plasmodesmata and phloem vasculature for their local and long-distance transports to establish systemic infection ...in plants. In contrast to well-studied virus local transports, molecular mechanisms and related host genes governing virus systemic trafficking are far from being understood. Here, we performed a forward genetic screening to identify Arabidopsis thaliana mutants with enhanced susceptibility to a 2b-deleted mutant of cucumber mosaic virus (CMV-2aT∆2b). We found that an uncharacterized Piezo protein (AtPiezo), an ortholog of animal Piezo proteins with mechanosensitive (MS) cation channel activities, was required for inhibiting systemic infection of CMV-2aT∆2b and turnip mosaic virus tagged a green fluorescent protein (GFP) (TuMV-GFP). AtPiezo is induced by virus infection, especially in the petioles of rosette leaves. Thus, we for the first time demonstrate the biological function of Piezo proteins in plants, which might represent a common antiviral strategy because many monocot and dicot plant species have a single Piezo ortholog.
Chaos in nonlinear dynamical systems is featured with irregular appearance and with high sensitivity to initial conditions. Near-infrared light chaos based on semiconductor lasers has been ...extensively studied and has enabled various applications. Here, we report a fully-developed hyperchaos in the mid-infrared regime, which is produced from interband cascade lasers subject to the external optical feedback. Lyapunov spectrum analysis demonstrates that the chaos exhibits three positive Lyapunov exponents. Particularly, the chaotic signal covers a broad frequency range up to the GHz level, which is two to three orders of magnitude broader than existed mid-infrared chaos solutions. The interband cascade lasers produce either periodic oscillations or low-frequency fluctuations before bifurcating to hyperchaos. This hyperchaos source is valuable for developing long-reach secure optical communication links and remote chaotic Lidar systems, taking advantage of the high-transmission windows of the atmosphere in the mid-infrared regime.
Ceramic stereolithography (CSL) is an additive manufacturing method for creating ceramic three-dimensional (3D) objects via the layer-by-layer photopolymerization of a ceramic suspension. A key ...challenge in CSL is that support structures are required for building overhanging structures to prevent part damage or deformation caused by gravity or process-induced shears. Removing the support structures can result in issues such as poor surface quality, high risk of cracking, etc. To overcome this challenge, this article presents a new CSL-based ceramic fabrication method that uses an elasto-viscoplastic ceramic suspension as the feedstock material. The suspension’s inherently strong interparticle resistive force can support overhangs without the need for building additional support structures; a temperature-controlled layer-coating module is designed to dynamically form a localized suspension bridge above the free surface of previously deposited materials, which allows for the application of fresh thin layers with a controlled shear force. The article presents material design and characterizations and discusses key process parameters and their effects on the geometry retention of fabricated overhangs. This new process provides the potential for fabricating ceramic 3D objects with complex overhangs, such as vascular networks, biomimetic heat exchangers, and microreactors.
The variation in the high-energy cutoff, Ec, in active galactic nuclei (AGNs) uniquely probes the corona physics. In this work, we show that the ratio of two NuSTAR spectra (analogous to the ...difference-imaging technique widely used in astronomy) is uniquely useful in studying Ec variations. The spectra ratio could directly illustrate potential Ec variation between two spectra. By comparing with the ratio of two spectral-fitting models, it also examines the reliability of the spectral fitting measured Ec variation. Assisted with this technique, we revisit the five AGNs in the literature (MCG-5-23-16, 3C 382, NGC 4593, NGC 5548, and Mrk 335), for which Ec (kTe) variations have been claimed with NuSTAR observations. We show that the claimed Ec variations appear inconsistent with the spectra ratios in three of them, thus they need to be revised, demonstrating the striking usefulness of spectra ratio. We present thereby improved spectral-fitting results and Ec variations. We also report a new source with Ec variations based on NuSTAR observations (radio galaxy 4C+74.26). We find the corona tends to be hotter when it brightens (hotter-when-brighter) in 3C 382, NGC 5548, Mrk 335, and 4C+74.27, but MCG-5-23-16 and NGC 4593 show no evidence of significant Ec variations. Meanwhile, all six sources in this small sample appear softer when brighter. Changes in corona geometry are required to explain the observed hotter-when-brighter trends.
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