Self-powered electronic skin (E-skin) can be endowed with high robustness by employing self-healing materials. However, most self-powered E-skin employs two heterogeneous materials with high modulus ...mismatch at the interface and poor fully self-healing ability, which reduces the robustness of the whole device. Here, a conductive polyurethane elastomer (PUE) with excellent mechanical toughness and self-healing ability is prepared. Based on the self-healing insulated/conductive PUE homogeneous structure and triboelectric–electrostatic induction effect, a highly robust and self-powered E-skin (HRSE-skin) is developed. The HRSE-skin possesses stable mechanosensation capability during the 50% stretching deformation due to a low modulus mismatch in the homogeneous structure. In addition, the stretchability and mechanosensation capability of the HRSE-skin can be restored after the fracture owing to the fully self-healing ability of the homogeneous structure. Therefore, the HRSE-skin has high robustness of the whole device including stable service behaviors and excellent restorability. The developed HRSE-skin demonstrates high robustness in the detection of the force and bending angle of the prosthetic joint. This work solves the low robustness of self-powered E-skin by the preparation of conductive self-healing PUE and the construction of the homogeneous structure, which is important for the practical applications of self-powered E-skin in prosthetic limbs and advanced robotics.
Automatic detection of kiwifruit in the orchard is challenging because illumination varies through the day and night and because of color similarity between kiwifruit and the complex background of ...leaves, branches and stems. Also, kiwifruits grow in clusters, which may result in having occluded and touching fruits. A fast and accurate object detection algorithm was developed to automatically detect kiwifruits in the orchard by improving the YOLOv3-tiny model. Based on the characteristics of kiwifruit images, two convolutional kernels of 3 × 3 and 1 × 1 were added to the fifth and sixth convolution layers of the YOLOv3-tiny model, respectively, to develop a deep YOLOv3-tiny (DY3TNet) model. It takes multiple 1 × 1 convolutional layers in intermediate layers of the network to reduce the computational complexity. Testing images captured from day and night and comparing with other deep learning models, namely, Faster R-CNN with ZFNet, Faster R-CNN with VGG16, YOLOv2 and YOLOv3-tiny, the DY3TNet model achieved the highest average precision of 0.9005 with the smallest data weight of 27 MB. Furthermore, it took only 34 ms on average to process an image of a resolution of 2352 × 1568 pixels. The DY3TNet model, along with the YOLOv3-tiny model, showed better performance on images captured with flash than those without. Moreover, the experiments indicated that the image augmentation process could improve the detection performance, and a simple lighting arrangement could improve the success rate of detection in the orchard. The experimental results demonstrated that the improved DY3TNet model is small and efficient and that it would increase the applicability of real-time kiwifruit detection in the orchard even when small hardware devices are used.
Since the invention of the triboelectric nanogenerator (TENG) in 2012, it has become one of the most vital innovations in energy harvesting technologies. The TENG has seen enormous progress to date, ...particularly in applications for energy harvesting and self-powered sensing. It starts with the simple working principles of the triboelectric effect and electrostatic induction, but can scavenge almost any kind of ambient mechanical energy in our daily life into electricity. Extraordinary output performance optimization of the TENG has been achieved, with high area power density and energy conversion efficiency. Moreover, TENGs can also be utilized as self-powered active sensors to monitor many environmental parameters. This review describes the recent progress in mainstream energy harvesting and self-powered sensing research based on TENG technology. The birth and development of the TENG are introduced, following which structural designs and performance optimizations for output performance enhancement of the TENG are discussed. The major applications of the TENG as a sustainable power source or a self-powered sensor are presented. The TENG, with rationally designed structures, can convert irregular and mostly low-frequency mechanical energies from the environment, such as human motion, mechanical vibration, moving automobiles, wind, raindrops, and ocean waves. In addition, the development of self-powered active sensors for a variety of environmental simulations based on the TENG is presented. The TENG plays a great role in promoting the development of emerging Internet of Things, which can make everyday objects connect more smartly and energy-efficiently in the coming years. Finally,the future directions and perspectives of the TENG are outlined. The TENG is not only a sustainable micro-power source for small devices, but also serves as a potential macro-scale generator of power from water waves in the future.
A deep red-emitting Ba2MgGe2O7:Mn4+ (BMG:Mn4+) phosphor was synthesized by conventional solid-state reaction. 4A2g→4T1g, 4A1g→4T2g, and 4A2g→2T2g transitions of Mn4+ ions resulted in three absorption ...bands centered at 305, 330, and 420 nm, respectively. The phosphor showed a broad emission band from 600 nm to 700 nm due to 2E→4A2 transition of Mn4+ ions. The highest luminous peak located at 660 nm, and the highest luminous intensity was achieved at high Mn4+ concentration (0.013). Multipolar interaction was the major mechanism for fluorescence quenching, and dipole–dipole interaction was the type of interaction mechanism between Mn4+ ions. Fluorescence lifetimes decreased from 0.898 ms to 0.746 ms, which accorded with the requirement of white light-emitting diode phosphor. Color coordinates of BMG:Mn4+ phosphors (0.721, 0.279) were close to the standard values of the National TV Standards Committee.
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•A method of concrete CT image segmentation based on mask and regional convolution neural network is proposed.•The proposed segmentation method is more accurate to identify the ...meso-damage of concrete.•The propagation of cracks in concrete under load could be divided into compaction, expansion, and deformation stages.
The meso-damage of concrete structure has an important impact on the macro-damage. X-ray CT technology, as a non-destructive testing method, is one of great significance to the study of concrete meso-structure. However, since the traditional CT scanning image segmentation methods cannot effectively identify and segment structural meso-defects autonomously. In order to solve this problem, a new method for meso-crack segmentation and extraction of concrete CT scanning images based on regional convolution neural network (Mask R-CNN) is proposed and applied to segment the images obtained from the real-time CT test under static uniaxial compression. Results showed that the segmentation accuracy of voids and cracks in the CT images is 0.957 and 0.931 respectively, which verifies the effectiveness of the method that can be used to high-precision recognize voids and cracks from CT scanning images of concrete. Additionally, the segmented images of internal voids and cracks in concrete are adopted to accurately 3D reconstruction to investigate the meso-cracks propagation under real-time loading based on CT.
Pancreatic cancer is a highly aggressive malignancy characterized by poor survival, recurrence after surgery and resistance to therapy. Nerves infiltrate the microenvironment of pancreatic cancers ...and contribute to tumor progression, however the clinicopathological significance of tumor innervation is unclear. In this study, the presence of nerves and their cross-sectional size were quantified by immunohistochemistry for the neuronal markers S-100, PGP9.5 and GAP-43 in a series of 99 pancreatic cancer cases versus 71 normal adjacent pancreatic tissues. A trend was observed between the presence of nerves in the tumor microenvironment of pancreatic cancer and worse overall patient survival (HR = 1.8, 95% CI 0.77-4.28, p = 0.08). The size of nerves, as measured by cross-sectional area, were significantly higher in pancreatic cancer than in the normal adjacent tissue (p = 0.002) and larger nerves were directly associated with worse patient survival (HR = 0.41, 95% CI 0.19-0.87, p = 0.04). In conclusion, this study suggests that the presence and size of nerves within the pancreatic cancer microenvironment are associated with tumor aggressiveness.
In this study, the mechanical behaviors, failure characteristics, and microstructure of concrete containing fly ash (FA) against combined freeze-thaw cycles and sulfate attack were studied compared ...with normal concrete, and the formation rates of corrosion products during coupling cycles were investigated. Results showed that, during the coupling action of freeze-thaw cycles and sodium sulfate solution, concrete containing 10% fly ash exposed in 5% sodium sulfate solution exhibited better freeze-thaw resistance. Meanwhile, the variation of compressive strength of concrete during the coupling cycles could be divided into two stages, including the strength enhancement stage and the strength reduction stage. Moreover, the proportion of micropores and capillary pores decreased obviously during combined freeze-thaw cycles and sulfate attack, and excessive concentration of sodium sulfate solution led to more macropores after high-frequency freeze-thaw cycles.
Background
Ulcerative colitis (UC) is characterized by chronic inflammation in the colon and epigenetic factors underlying the occurrence. Circular RNAs (circRNAs) have been under intensive focus due ...to the circular construct and gene-regulating functions. However, the changes and roles of circRNAs in UC remain unknown.
Methods
Microarrays were used to detect the differentially expressed genes, and quantitative real-time PCR was used to identify the changes in UC. In silico analyses were performed to predict the functions of circRNAs and mRNAs. In vitro, epithelial cell lines were stimulated by pro-inflammation effectors to test the alterations in circRNAs. CircRNAs–microRNAs–mRNAs network clarified the potential mechanisms underlying circRNAs in UC. The binding site between hsa_circ_0007919 and miR-138 or let-7a was verified using dual-luciferase assay.
Results
A total of 264 significantly dysregulated circRNAs and 1869 differentially expressed mRNAs in inflamed mucosa were compared with the non-inflamed mucosa in UC. Hsa_circ_0004662 and hsa_circ_0007919 were altered largely in UC tissues. Hsa_circ_0007919 was reduced persistently after inflammatory treatments, and it was relevant to Mayo endoscopic subscores and the expression of tight junction molecules. Finally, hsa_circ_0007919 could harbor miR-138, and let-7a to regulate the targeted mRNAs EPC1 and VIPR1.
Conclusions
Several circRNAs were differentially expressed in UC. Hsa_circ_0007919 is related to clinical characteristics and epithelial integrity by binding to hsa-let-7a, hsa-miR-138 to regulate the target genes. CircRNAs, especially hsa_circ_0007919, are associated with the pathogenesis and development of UC, with potential diagnostic and therapeutic implications.
Nerve infiltration in the tumor microenvironment is emerging as a promoter of cancer progression that could be targeted in therapies, but the mechanisms initiating tumor innervation remain to be ...elucidated. Here we report that endoplasmic reticulum (ER) stress in cancer cells is transmitted to neuronal cells, resulting in neurite outgrowth and tumor innervation. In vitro, the induction of ER stress in various human cancer cells resulted in the synthesis and release of the precursor for brain-derived neurotrophic factor (proBDNF) through a mechanism dependent on the transcription factor X-box binding protein 1 (XBP1). Cancer cell-released proBDNF was found to mediate the transmission of ER stress to neurons, resulting in the stimulation of neurite outgrowth. Next-generation sequencing indicated the increased expression of the Egl-9 family hypoxia inducible factor 3 (EGLN3) that was mediated by c-MYC and necessary to neurite outgrowth induced by proBDNF. In orthotopic tumor xenograft, ER stress stimulated XBP1 and proBDNF expression as well as tumor innervation. Anti-proBDNF antibody inhibited both tumor innervation and cancer progression induced by ER stress. Interestingly, the chemotherapeutic drug 5-Fluorouracil (5-FU) was found to induce ER stress and tumor innervation, and this effect was inhibited by anti-proBDNF antibody. Finally, in human tumors, cancer tissues with nerve infiltration expressed high XBP1 and proBDNF while EGLN3 was upregulated in infiltrated nerves. This study reveals that ER stress participates in tumor innervation through the release of proBDNF and that targeting this pathway could be used in future therapies.
SLC7A11 controls the uptake of extracellular cystine in exchange for glutamate at a ratio of 1:1, and it is overexpressed in a variety of tumours. Accumulating evidence has shown that the expression ...of SLC7A11 is fine-tuned at multiple levels, and plays diverse functional and pharmacological roles in tumours, such as cellular redox homeostasis, cell growth and death, and cell metabolism. Many reports have suggested that the inhibition of SLC7A11 expression and activity is favourable for tumour therapy; thus, SLC7A11 is regarded as a potential therapeutic target. However, emerging evidence also suggests that on some occasions, the inhibition of SLC7A11 is beneficial to the survival of cancer cells, and confers the development of drug resistance. In this review, we first briefly introduce the biological properties of SLC7A11, including its structure and physiological functions, and further summarise its regulatory network and potential regulators. Then, focusing on its role in cancer, we describe the relationships of SLC7A11 with tumourigenesis, survival, proliferation, metastasis, and therapeutic resistance in more detail. Finally, since SLC7A11 has been linked to cancer through multiple approaches, we propose that its contribution and regulatory mechanism require further elucidation. Thus, more personalised therapeutic strategies should be adapted when targeting SLC7A11.
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