When given a group of relevant images for co-salient object detection (Co-SOD), humans first summarize consensus cues from the whole group and then search for co-salient objects in each image. Most ...previous methods do not consider robustness, scalability, or stability in the summarization stage and adopt a simple fusion strategy to fuse consensus and image features in the searching stage. Our work presents a novel consensus-aware dynamic convolution (CADC) model directly from the "summarize and search" perspective to explicitly and effectively perform Co-SOD. For the summarization stage, we extract robust individual image features by a pooling method and integrate them to generate consensus features via self-attention, thus modeling the scalability and stability. Then, we simultaneously learn two types of consensus-aware dynamic kernels, i.e., a common kernel to capture group-wise common knowledge and adaptive kernels to mine image-specific consensus cues. For the second stage, we adopt dynamic convolution to perform object searching. A novel data synthesis strategy is also developed for model training. Although CADC has obtained competitive performance, we argue that incrementally learning dynamic kernels and representations is more intuitive and natural instead of using a simultaneous scheme, thus presenting our CADC ++ , an extension of CADC. Concretely, we first adopt the common kernel based dynamic convolution to capture coarse common cues as priors and then use the adaptive kernel based dynamic convolution for mining image-specific details. We also propose a recursive guidance strategy to further explore deep interactions among the two kinds of kernels and image features. Besides, we annotate several challenging attributes for Co-SOD datasets and perform attribute-based evaluation and robustness analysis to promote thorough model evaluation for the Co-SOD field. Extensive experimental results on four benchmark datasets verify both the effectiveness and robustness of our proposed method.
Circular RNAs (circRNAs) produced from back-splicing of exons of pre-mRNAs are widely expressed, but current understanding of their functions is limited. These RNAs are stable in general and are ...thought to have unique structural conformations distinct from their linear RNA cognates. Here, we show that endogenous circRNAs tend to form 16–26 bp imperfect RNA duplexes and act as inhibitors of double-stranded RNA (dsRNA)-activated protein kinase (PKR) related to innate immunity. Upon poly(I:C) stimulation or viral infection, circRNAs are globally degraded by RNase L, a process required for PKR activation in early cellular innate immune responses. Augmented PKR phosphorylation and circRNA reduction are found in peripheral blood mononuclear cells (PBMCs) derived from patients with autoimmune disease systemic lupus erythematosus (SLE). Importantly, overexpression of the dsRNA-containing circRNA in PBMCs or T cells derived from SLE can alleviate the aberrant PKR activation cascade, thus providing a connection between circRNAs and SLE.
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•circRNAs are globally degraded by activated RNase L upon viral infection•Many circRNAs tend to form 16–26 bp duplexes and act as endogenous PKR inhibitors•The RNase L-mediated circRNA degradation is required for PKR activation•circRNA reduction and aberrant PKR activation are found in autoimmune disease SLE
The unique structure of circRNAs allows them to bind and regulate the innate immune dsRNA receptor PKR, and misregulation of this process is found in patients with autoimmune disease.
Although MoS2 field-effect transistors (FETs) with high-k dielectrics are promising for electron device applications, the underlying physical origin of interface degradation remains largely ...unexplored. Here, we present a systematic analysis of the energy distribution of the interface state density (Dit) and the quantum capacitance (CQ) in a dual-gate monolayer exfoliated MoS2 FET. The CQ analysis enabled us to construct a Dit extraction method as a function of EF. A band tail distribution of Dit with the lowest value of 8 × 1011 cm−2 eV−1 suggests that Dit is not directly related to the sharp peak energy distribution of the S vacancy. Therefore, the Mo-S bond bending related to the strain at the interface or the surface roughness of the SiO2/Si substrate might be the origin. It is also shown that ultra-thin 2D materials are more sensitive to interface disorder due to the reduced density of states. Since all the constituents for the measured capacitance are well understood, I-V characteristics can be reproduced by utilizing the drift current model. As a result, one of the physical origins of the metal/insulator transition is suggested to be the external outcome of interface traps and quantum capacitance.
The mechanical simplicity, hover capabilities, and high agility of quadrotors lead to a fast adaption in the industry for inspection, exploration, and urban aerial mobility. On the other hand, the ...unstable and underactuated dynamics of quadrotors render them highly susceptible to system faults, especially rotor failures. In this work, we propose a fault-tolerant controller using nonlinear model predictive control (NMPC) to stabilize and control a quadrotor subjected to the complete failure of a single rotor. Differently from existing works, which either rely on linear assumptions or resort to cascaded structures neglecting input constraints in the outer-loop, our method leverages full nonlinear dynamics of the damaged quadrotor and considers the thrust constraint of each rotor. Hence, this method could effectively perform upset recovery from extreme initial conditions. Extensive simulations and real-world experiments are conducted for validation, which demonstrates that the proposed NMPC method can effectively recover the damaged quadrotor even if the failure occurs during aggressive maneuvers, such as flipping and tracking agile trajectories.
Understanding the operation mode of a two-dimensional (2D) material-based field-effect transistor (FET) is one of the most essential issues in the study of electronics and physics. The existing ...Schottky barrier FET model for devices with global back gate and metallic contacts overemphasizes the metal/2D contact effect, and the widely observed residual conductance cannot be explained by this model. Here, an accumulation-mode (ACCU) FET model, which directly reveals 2D channel transport properties, is developed based on a partial top-gate MoS2 FET with metallic contacts and a channel thickness of 0.65–118 nm. The operation mechanism of an ACCU-FET is validated and clarified by carefully performed capacitance measurements. A depletion capacitance–quantum capacitance transition is observed. After the analysis of the MoS2 ACCU-FET, we have confirmed that most 2D FETs show an accumulation-mode behavior. The universal thickness scaling rule of 2D-FETs is then proposed, which provides guidance for future research on 2D materials.
Non‐covalent modification method has been proven as an effective strategy for enhancing the chemical properties of graphene while the structure and electronic properties of graphene can be retained. ...This work describes a novel strategy to fabricate a solid‐state electrochemiluminescent (ECL) immunosensor based on ruthenium(II) complex/3,4,9,10‐perylenetetracarboxylic acid (PTCA)/graphene nanocomposites (Ru‐PTCA/G) for sensitive detection of α‐fetoprotein (AFP). It is found that immobilization of PTCA and reduction of GO can be simultaneously achieved in one‐pot synthesis method under alkaline condition and moderate temperature, forming PTCA/G nanocomposites. Further covalent attachment of ruthenium(II) complex to the PTCA assembled on graphene sheets produces the functional Ru‐PTCA/G nanocomposites which show good electrochemical activity and ca. 21 times higher luminescence quantum efficiency than the adsorbed derivative ruthenium(II) complex. The Ru‐PTCA/G nanocomposites based solid‐state ECL sensor exhibits high stability toward the determination of tripropylamine (TPA) coreactant. In addition, a new ECL immunosensor based on steric hindrance effect is fabricated by cross‐linking α‐fetoprotein antibody (anti‐AFP) with chitosan covered on Ru‐PTCA/G composites modified electrode for detection of cancer biomarker AFP. This ECL immunosensor shows an extremely sensitive response to AFP in a linear range of 5 pg·mL‐1–10 ng·mL‐1 with a detection limit of 0.2 pg·mL‐1. The present approach is effective for various molecules immobilization and may become a promising technique for biomolecular detection.
A novel, simultaneous immobilization of PTCA and reduction of GO method is developed for fabrication of PTCA/G. Further covalent attachment of Ru(II) to PTCA/G produces Ru‐PTCA/G nanocomposite which shows good electrochemical activity and ca. 21 times higher luminescence quantum efficiency than the adsorbed Ru(II). In addition, a new ECL immunosensor based on steric hindrance effect is fabricated for detection of cancer biomarker AFP.
Background Diabetic foot ulcer (DFU) is a chronic infectious disease caused by diabetes mellitus (DM). Angiogenesis plays the decisive role in wound healing of DFU. Adipose-derived stem cells (ADSCs) ...can ameliorate angiogenesis in DFU by exosomes. This study aims to determine the mechanism of exosomes from mmu_circ_0001052-modified ADSCs in angiogenesis of DFU. Methods HUVECs were induced by high glucose and mice stimulated using STZ injection during high-fat feeding, which were treated with exosomes derived from mmu_circ_0001052-modified ADSCs. Real-time PCR determined the expression of gene and western blot determined protein levels. Proliferation, migration, apoptosis and angiogenesis of HUVECs were studied by MTT assay, transwell test, flow cytometry and tube formation experiment, respectively. Histological lesion of wound was determined by HE staining. Results The expression of circ_0001052 was upregulated in ADSCs and miR-106a-5p elevated in high glucose-induced HUVECs. Exosomal mmu_circ_0001052 significantly accelerated wound healing in mice with DFU. Also, exosomal mmu_circ_0001052 evoked the reduction of miR-106a-5p and the elevation of FGF4 in high glucose-induced HUVECs and wound tissue of DFU mice. Exosomal mmu_circ_0001052 was determined to sponge miR-106a-5p that targeted FGF4 in DFU. In high glucose-induced HUVECs, exosomal mmu_circ_0001052 inhibited apoptosis and miR-106a-5p expression, and meanwhile promoted proliferation, migration, angiogenesis and expressions of FGF4, VEGF and p-p38/p38, which were reversed by miR-106a-5p elevation. Conclusion Mmu_circ_0001052 in ADSCs-derived exosomes promote angiogenesis of DFU via miR-106a-5p and FGF4/p38MAPK pathway. Graphical Keywords: Diabetic foot ulcer, mmu_circ_0001052, miR-106a-5p, FGF4/p38MAPK pathway, Angiogenesis
2D materials are promising to overcome the scaling limit of Si field‐effect transistors (FETs). However, the insulator/2D channel interface severely degrades the performance of 2D FETs, and the ...origin of the degradation remains largely unexplored. Here, the full energy spectra of the interface state densities (Dit) are presented for both n‐ and p‐ MoS2 FETs, based on the comprehensive and systematic studies, i.e., full rage of channel thickness and various gate stack structures with h‐BN as well as high‐k oxides. For n‐MoS2, Dit around the mid‐gap is drastically reduced to 5 × 1011 cm−2 eV−1 for the heterostructure FET with h‐BN from 5 × 1012 cm−2 eV−1 for the high‐k top‐gate. On the other hand, Dit remains high, ≈1013 cm−2 eV−1, even for the heterostructure FET for p‐MoS2. The systematic study elucidates that the strain induced externally through the substrate surface roughness and high‐k deposition process is the origin for the interface degradation on conduction band side, while sulfur‐vacancy‐induced defect states dominate the interface degradation on valance band side. The present understanding of the interface properties provides the key to further improving the performance of 2D FETs.
The interfacial properties of both n‐ and p‐MoS2 field‐effect transistors with a wide thickness range and various gate stack structures are investigated. The full energy spectra of the interface state densities are extracted. The external strain dominates the interface at the conduction band side, while sulfur‐vacancy‐induced defect‐states dominate the valance band side.
•Fe isotope compositions of Bayan Obo ore deposit have been investigated systematically for the first time.•The fine-grained iron ores have homogeneous Fe isotope compositions.•The Fe isotope ...fractionation between Fe oxide minerals and carbonate is limited.•It is demonstrated that the ore deposit is of magmatic origin.
The giant polymetallic Bayan Obo REE-Nb-Fe ore deposit is the largest REE deposit in the world. Despite the fact that a great number of works have been done on the deposit, its origin remains controversial. Various genetic models have been proposed, including sedimentary origin, magmatic origin, hydrothermal origin or origin with multiple processes. Here the Fe isotope compositions of different types of rocks from the deposit and related geological formations, such as carbonatites, mafic dykes, and Mesoproterozoic sedimentary iron formation and carbonates, are systematically investigated. For the ore deposit, the average δ56Fe values are −0.03±0.16‰ (2SD, n=14), 0.01‰±0.24‰ (2SD, n=6), −0.07±0.24‰ (2SD, n=19) for bulk samples of fine-grained iron ores, gangue rocks and ore-hosting dolomite marble, respectively; and 0.01±0.14 (2SD, n=14), 0.08±0.18 (2SD, n=3), −0.21 for the magnetite, hematite and dolomite, the main Fe oxide and carbonate minerals in the deposit. The narrow range of the near-zero δ56Fe values of fine-grained iron ores and Fe oxide minerals are consistent with those of magmatic products such as igneous rocks and magmatic iron ores, but different from those of sedimentary or hydrothermal products like Precambrian sedimentary iron formations and hydrothermal iron ores reported previously. The slightly negative Fe isotope values of the ore-hosting dolomite marble are consistent with those of the carbonatite dykes in Bayan Obo area and the typical carbonatites worldwide, but different from those of Mesoproterozoic sedimentary carbonates. The small Fe isotope fractionations between magnetite and dolomite (Δ56Femagnetite-dolomite≈0.23‰), and between hematite and magnetite (Δ56Fehematite-magnetite≈0.07‰), indicate that the ore deposit experienced a very high temperature. Overall, the Fe isotope compositions are inconsistent with either sedimentary or hydrothermal origin, but support a magmatic origin for the Bayan Obo deposit.
Lung cancer is a highly heterogeneous disease. Cancer cells and cells within the tumor microenvironment together determine disease progression, as well as response to or escape from treatment. To map ...the cell type-specific transcriptome landscape of cancer cells and their tumor microenvironment in advanced non-small cell lung cancer (NSCLC), we analyze 42 tissue biopsy samples from stage III/IV NSCLC patients by single cell RNA sequencing and present the large scale, single cell resolution profiles of advanced NSCLCs. In addition to cell types described in previous single cell studies of early stage lung cancer, we are able to identify rare cell types in tumors such as follicular dendritic cells and T helper 17 cells. Tumors from different patients display large heterogeneity in cellular composition, chromosomal structure, developmental trajectory, intercellular signaling network and phenotype dominance. Our study also reveals a correlation of tumor heterogeneity with tumor associated neutrophils, which might help to shed light on their function in NSCLC.
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