51 research outputs found

    AiATrack: Attention in Attention for Transformer Visual Tracking

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    Transformer trackers have achieved impressive advancements recently, where the attention mechanism plays an important role. However, the independent correlation computation in the attention mechanism could result in noisy and ambiguous attention weights, which inhibits further performance improvement. To address this issue, we propose an attention in attention (AiA) module, which enhances appropriate correlations and suppresses erroneous ones by seeking consensus among all correlation vectors. Our AiA module can be readily applied to both self-attention blocks and cross-attention blocks to facilitate feature aggregation and information propagation for visual tracking. Moreover, we propose a streamlined Transformer tracking framework, dubbed AiATrack, by introducing efficient feature reuse and target-background embeddings to make full use of temporal references. Experiments show that our tracker achieves state-of-the-art performance on six tracking benchmarks while running at a real-time speed.Comment: Accepted by ECCV 2022. Code and models are publicly available at https://github.com/Little-Podi/AiATrac

    Inside-out Ca2+ signalling prompted by STIM1 conformational switch

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    Store-operated Ca(2+) entry mediated by STIM1 and ORAI1 constitutes one of the major Ca(2+) entry routes in mammalian cells. The molecular choreography of STIM1–ORAI1 coupling is initiated by endoplasmic reticulum (ER) Ca(2+) store depletion with subsequent oligomerization of the STIM1 ER-luminal domain, followed by its redistribution towards the plasma membrane to gate ORAI1 channels. The mechanistic underpinnings of this inside-out Ca(2+) signalling were largely undefined. By taking advantage of a unique gain-of-function mutation within the STIM1 transmembrane domain (STIM1-TM), here we show that local rearrangement, rather than alteration in the oligomeric state of STIM1-TM, prompts conformational changes in the cytosolic juxtamembrane coiled-coil region. Importantly, we further identify critical residues within the cytoplasmic domain of STIM1 (STIM1-CT) that entail autoinhibition. On the basis of these findings, we propose a model in which STIM1-TM reorganization switches STIM1-CT into an extended conformation, thereby projecting the ORAI-activating domain to gate ORAI1 channels

    Identification of key genes and pathways involved in response to pain in goat and sheep by transcriptome sequencing

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    Abstract Purpose This aim of this study was to investigate the key genes and pathways involved in the response to pain in goat and sheep by transcriptome sequencing. Methods Chronic pain was induced with the injection of the complete Freund’s adjuvant (CFA) in sheep and goats. The animals were divided into four groups: CFA-treated sheep, control sheep, CFA-treated goat, and control goat groups (n = 3 in each group). The dorsal root ganglions of these animals were isolated and used for the construction of a cDNA library and transcriptome sequencing. Differentially expressed genes (DEGs) were identified in CFA-induced sheep and goats and gene ontology (GO) enrichment analysis was performed. Results In total, 1748 and 2441 DEGs were identified in CFA-treated goat and sheep, respectively. The DEGs identified in CFA-treated goats, such as C-C motif chemokine ligand 27 (CCL27), glutamate receptor 2 (GRIA2), and sodium voltage-gated channel alpha subunit 3 (SCN3A), were mainly enriched in GO functions associated with N-methyl-d-aspartate (NMDA) receptor, inflammatory response, and immune response. The DEGs identified in CFA-treated sheep, such as gamma-aminobutyric acid (GABA)-related DEGs (gamma-aminobutyric acid type A receptor gamma 3 subunit [GABRG3], GABRB2, and GABRB1), SCN9A, and transient receptor potential cation channel subfamily V member 1 (TRPV1), were mainly enriched in GO functions related to neuroactive ligand-receptor interaction, NMDA receptor, and defense response. Conclusions Our data indicate that NMDA receptor, inflammatory response, and immune response as well as key DEGs such as CCL27, GRIA2, and SCN3A may regulate the process of pain response during chronic pain in goats. Neuroactive ligand-receptor interaction and NMDA receptor as well as GABA-related DEGs, SCN9A, and TRPV1 may modulate the process of response to pain in sheep. These DEGs may serve as drug targets for preventing chronic pain

    A nano-TiO2/regenerated cellulose biohybrid enabled simultaneous improvements in strength and toughness for solid epoxy resins

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    The intrinsic brittleness has significantly restricted practical applications of epoxy resins. Existing toughening strategies often lead to degraded mechanical strength. Hence, it has been attractive but a huge challenge to design high-performance sustainable additives that can simultaneously improve strength and toughness of epoxy resins. Here, we report the synthesis of a nano-TiO2/regenerate cellulose (RC) biohybrid via a facile microwave method for strengthening and toughening a soft epoxy resin system (modulus below 1 GPa). Our results show that with 10 phr nano-TiO2/RC, the resultant epoxy composite exhibits simultaneous enhancements in tensile strength and impact toughness, ca. 38% and 40% higher than corresponding values of virgin epoxy resin because of improved interfacial compatibility. Moreover, the addition of as-designed nano-TiO2/RC can enhance thermostability of epoxy resin. It has a slightly negative effect on the curing reaction but does not change the curing mechanism of epoxy resins. This study provides a facile, efficient and green method for preparing bifunctional additive for creating strong and tough epoxy composites, which are expected to find wider applications in industries

    Engineering Interfaces toward High-Performance Polypropylene/Coir Fiber Biocomposites with Enhanced Friction and Wear Behavior

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    High-performance natural plant fibers reinforced polymer biocomposites with excellent friction and wear properties hold significant practical applications in industry. Unfortunately, it remains a major challenge to engineer the interfacial interactions between the fibers and the polymer matrix, which determines the mechanical and wear properties of the final composites. Herein, we engineer the coir fiber surface by depositing polyethylenimine (PEI) and graphene nanosheets and then prepare the polypropylene/coir fiber biocomposites. As compared with unmodified coir fibers, graphene decorated coir fibers can remarkably reduce the friction and wear, with the lowest friction coefficient at 0.19 and wear rate at 3.5 × 10–7 g/r. The excellent friction-reducing and wear-resistance performances are mainly attributed to three factors, namely the enhanced interfacial bonding, optimized crystallinity, and the formation of a transfer film. The transfer film is comprised of a polypropylene, PEI, and graphene nanosheets. This work provides a facile methodology for the design of high-performance polymer biocomposites with enhanced friction and wear behaviors. The results can also contribute to expand the practical applications of polymer biocomposites in industry

    Graft polymerization of acrylic monomers onto lignin with CaCl2-H2O2 as initiator: preparation, mechanism, characterization, and application in poly(lactic acid)

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    Effective utilization of abundant industrial lignin has growingly attracted much attention besides potential environmental issues. Although chemical graft polymerization modification is one facile strategy for extending its applications, it remains an intractable challenge to select a highly efficient initiation system. We herein have attempt to understand the CaCl2−H2O2 system in initiating the graft polymerization of acrylic monomers onto acetic acid lignin (AAL) and biobutanol lignin (BBL). The initiation system is found to be highly efficient and selective, as proved by the successful graft of polyacrylates onto them, and a possible mechanism is also proposed. Thermal analysis shows that the graft modification results in a higher glass transition temperature and higher thermal stability of lignin. The graft modification make both AAL and BBL become more hydrophobic than before modification. Moreover, adding a small amount of lignin-graft-polyacrylate can considerably improve the UV blocking capability in addition to the reinforcing effect on polylactic acid. This work offers a novel, highly effective, and selective free radical initiation system for functionalizing lignin

    Deletion of Cdc42 in embryonic cardiomyocytes results in right ventricle hypoplasia

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    Abstract Background Cdc42 is a member of the Rho GTPase family and functions as a molecular switch in regulating cytoskeleton remodeling and cell polarity establishment. Inactivating Cdc42 in cardiomyocytes resulted in embryonic lethality with heart developmental defects, including ventricular septum defects and thin ventricle wall syndrome. Findings In this study, we have generated a Cdc42 cardiomyocyte knockout mouse line by crossing Cdc42/flox mice with myosin light chain 2a (MLC2a)-Cre mice. We found that the deletion of Cdc42 in embryonic cardiomyocytes resulted in an underdeveloped right ventricle. Microarray analysis and real-time PCR data analysis displayed that the deletion of Cdc42 decreased dHand expression level. In addition, we found evaginations in the ventricle walls of Cdc42 knockout hearts. Conclusion We concluded that Cdc42 plays an essential role in right ventricle growth

    Graft polymerization of acrylic monomers onto lignin with CaCl2-H2O2 as initiator: preparation, mechanism, characterization, and application in poly(lactic acid)

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    Effective utilization of abundant industrial lignin has growingly attracted much attention besides potential environmental issues. Although chemical graft polymerization modification is one facile strategy for extending its applications, it remains an intractable challenge to select a highly efficient initiation system. We herein have attempt to understand the CaCl2−H2O2 system in initiating the graft polymerization of acrylic monomers onto acetic acid lignin (AAL) and biobutanol lignin (BBL). The initiation system is found to be highly efficient and selective, as proved by the successful graft of polyacrylates onto them, and a possible mechanism is also proposed. Thermal analysis shows that the graft modification results in a higher glass transition temperature and higher thermal stability of lignin. The graft modification make both AAL and BBL become more hydrophobic than before modification. Moreover, adding a small amount of lignin-graft-polyacrylate can considerably improve the UV blocking capability in addition to the reinforcing effect on polylactic acid. This work offers a novel, highly effective, and selective free radical initiation system for functionalizing lignin

    Lignin-derived porous carbon loaded with La(OH)3 nanorods for highly efficient removal of phosphate

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    Removing phosphate ions from eutrophic waters is of paramount importance; however, the design of low-cost, high-performance adsorbents for phosphorus removal has remained a huge challenge. Herein, we have demonstrated the fabrication of a low-cost, eco-friendly absorbent, LPC@La(OH)3, by loading lanthanum hydroxide nanorods within lignin-derived porous carbon for superfast and highly efficient phosphorus removal. As-prepared LPC@ La(OH)3 exhibits a high adsorption capacity of 60.24 mg PL−1 and a high lanthanum usage efficiency. Our results show an ultrafast removal of up to 99.5% phosphate in 10 min when the initial concentration is 2 mg P L−1. Moreover, LPC@La(OH)3 can efficiently reduce the phosphate concentration to meet the below U.S. Environmental Protection Agency limits (50 μgPL−1) for eutrophication prevention. More importantly, it shows a high phosphate absorption ability over the wide range of pH 3−7, in addition to a high adsorption selectivity toward phosphate and high stability during adsorption process. Both the chemical precipitation and the ligand exchange are mainly responsible for the phosphate removal by LPC@La(OH)3. As-designed lignin-derived, ecofriendly, high-performance LPC@ La(OH)3 shows enormous potential for the phosphate removal from both municipal wastewater and industrial effluents
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