24 research outputs found

    Review on Machine Learning-based Defect Detection of Shield Tunnel Lining

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    At present, machine learning methods are widely used in various industries for their high adaptability, optimization function, and self-learning reserve function. Besides, the world-famous cities have almost built and formed subway networks that promote economic development. This paper presents the art states of Defect detection of Shield Tunnel lining based on Machine learning (DSTM). In addition, the processing method of image data from the shield tunnel is being explored to adapt to its complex environment. Comparison and analysis are used to show the performance of the algorithms in terms of the effects of data set establishment, algorithm selection, and detection devices. Based on the analysis results, Convolutional Neural Network methods show high recognition accuracy and better adaptability to the complexity of the environment in the shield tunnel compared to traditional machine learning methods. The Support Vector Machine algorithms show high recognition performance only for small data sets. To improve detection models and increase detection accuracy, measures such as optimizing features, fusing algorithms, creating a high-quality data set, increasing the sample size, and using devices with high detection accuracy can be recommended. Finally, we analyze the challenges in the field of coupling DSTM, meanwhile, the possible development direction of DSTM is prospected

    Design of EMI filter for high-power explosion-proof inverter

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    Generation mechanism of EMI in high-power explosion-proof inverter was analyzed, and design method of an EMI filter for high-power explosion-proof inverter was proposed. The EMI filter uses 'P' matching network structure based on a single LC filter, and realizes impedance matching of the explosion-proof inverter in the case of impedance mismatching, so as to improve EMI filtering effect. A 1 MW/1 140 V explosion-proof inverter was tested to verify validity of the EMI filter

    Two virulent sRNAs identified by genomic sequencing target the type III secretion system in rice bacterial blight pathogen

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    Abstract Background Small non-coding RNA (sRNA) short sequences regulate various biological processes in all organisms, including bacteria that are animal or plant pathogens. Virulent or pathogenicity-associated sRNAs have been increasingly elucidated in animal pathogens but little is known about similar category of sRNAs in plant-pathogenic bacteria. This is particularly true regarding rice bacterial blight pathogen Xanthomonas oryzae pathovar oryzae (Xoo) as studies on the virulent role of Xoo sRNAs is very limited at present. Results The number and genomic distribution of sRNAs in Xoo were determined by bioinformatics analysis based on high throughput sequencing (sRNA-Seq) of the bacterial cultures from virulence-inducing and standard growth media, respectively. A total of 601 sRNAs were identified in the Xoo genome and ten virulent sRNA candidates were screened out based on significant differences of their expression levels between the culture conditions. In addition, trans3287 and trans3288 were also selected as candidates due to high expression levels in both media. The differential expression of 12 sRNAs evidenced by the sRNA-Seq data was confirmed by a convincing quantitative method. Based on genetic analysis of Xoo ΔsRNA mutants generated by deletion of the 12 single sRNAs, trans217 and trans3287 were characterized as virulent sRNAs. They are essential not only for the formation of bacterial blight in a susceptible rice variety Nipponbare but also for the induction of hypersensitive response (HR) in nonhost plant tobacco. Xoo Δtrans217 and Δtrans3287 mutants fail to induce bacterial blight in Nipponbare and also fail to induce the HR in tobacco, whereas, genetic complementation restores both mutants to the wild type in the virulent performance and HR induction. Similar effects of gene knockout and complementation were found in the expression of hrpG and hrpX genes, which encode regulatory proteins of the type III secretion system. Consistently, secretion of a type III effector, PthXo1, is blocked in Δtrans217 or Δtrans3287 bacterial cultures but retrieved by genetic complementation to both mutants. Conclusions The genetic analysis characterizes trans217 and trans3287 as pathogenicity-associated sRNAs essential for the bacterial virulence on the susceptible rice variety and for the HR elicitation in the nonhost plant. The molecular evidence suggests that both virulent sRNAs regulate the bacterial virulence by targeting the type III secretion system

    An efficient multi-doping strategy to enhance Li-ion conductivity in the garnet-type solid electrolyte Li7La3Zr2O12

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    Lithium-ion (Li + ) batteries suffer from problems caused by the chemical instability of their organic electrolytes. Solid-state electrolytes that exhibit high ionic conductivities and are stable to lithium metal are potential replacements for flammable organic electrolytes. Garnet-type Li 7 La 3 Zr 2 O 12 is a promising solid-state electrolyte for next-generation solid-state Li batteries. In this study, we prepared mono-, dual-, and ternary-doped lithium (Li) garnets by doping tantalum (Ta), tantalum-barium (Ta-Ba), and tantalum-barium-gallium (Ta-Ba-Ga) ions, along with an undoped Li 7 La 3 Zr 2 O 12 (LLZO) cubic garnet electrolyte, using a conventional solid-state reaction method. The effect of multi-ion doping on the Li + dynamics in the garnet-type LLZO was studied by combining joint Rietveld refinement against X-ray diffraction and high-resolution neutron powder diffraction analyses with the results of Raman spectroscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and multinuclear magic angle spinning nuclear magnetic resonance. Our results revealed that Li + occupancy in the tetrahedrally coordinated site (24d) increased with increased multi-ion doping in LLZO, whereas Li + occupancy in the octahedrally coordinated site (96h) remained constant. Among the investigated compounds, the ternary-doped garnet structure Li 6.65 Ga 0.05 La 2.95 Ba 0.05 Zr 1.75 Ta 0.25 O 12 (LGLBZTO) exhibited the highest total ionic conductivity of 0.72 and 1.24 mS cm -1 at room temperature and 60 °C, respectively. Overall, our findings revealed that the dense microstructure and increased Li + occupancy in the tetrahedral-24d Li1 site played a key role in achieving the maximum room-temperature Li-ion conductivity in the ternary-doped LGLBZTO garnet, and that the prepared ternary-doped LGLBZTO was a potential solid electrolyte for Li-ion batteries without polymer adhesion

    Fibronectin mediates activin A-promoted human trophoblast migration and acquisition of endothelial-like phenotype

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    Abstract Background During human early placentation, a proportion of extravillous trophoblasts (EVTs) migrate to the maternal decidua, differentiating into endovascular EVTs to remodel spiral arteries and ensure the establishment of blood circulation at the maternal-fetal interface. Inadequate EVT migration and endovascular differentiation are closely associated with adverse pregnancy outcomes such as miscarriage. Activin A and fibronectin are both secretory molecules abundantly expressed at the maternal-fetal interface. Activin A has been reported to regulate EVT biological functions. However, whether fibronectin mediates activin A-promoted EVT migration and acquisition of endothelial-like phenotype as well as the underlying molecular mechanisms remain unknown. Additionally, the role of fibronectin in pregnancy establishment and maintenance warrants further investigation. Methods Primary and immortalized (HTR8/SVneo) human EVTs were used as in vitro study models. Cultured human first-trimester chorionic villous explants were utilized for ex vivo validation. A local fibronectin knockdown model in ICR mouse uteri, achieved by nonviral in vivo transfection with small interfering RNA (siRNA) targeting fibronectin 1 (si-Fn1), was employed to explore the roles of fibronectin in the establishment and maintenance of early pregnancy. Results Our results showed that activin A treatment significantly induced fibronectin 1 (FN1) mRNA expression and fibronectin protein production, which is essential for human trophoblast migration and endothelial-like tube formation. Both basal and activin A-upregulated fibronectin expression were abolished by the TGF-β type I receptor inhibitor SB431542 or siRNA-mediated knockdown of activin receptor-like kinase (ALK4) or SMAD4. Moreover, activin A-increased trophoblast migration and endothelial-like tube formation were attenuated following the depletion of fibronectin. Fibronectin knockdown via intrauterine siRNA administration reduced CD31 and cytokeratin 8 (CK8) expression at the maternal-fetal interface, resulting in a decrease in the number of implantation sites and embryos. Conclusions Our study demonstrates that activin A promotes trophoblast cell migration and acquisition of endothelial-like phenotype via ALK4-SMAD2/3-SMAD4-mediated fibronectin upregulation. Furthermore, through a local fibronectin knockdown model in mouse uteri, we found that the absence of fibronectin at the maternal-fetal interface impedes endovascular migration of trophoblasts and decidual vascularization, thereby interfering with early embryo implantation and the maintenance of pregnancy. These findings provide novel insights into placental development during early pregnancy establishment and contribute to the advancement of therapeutic approaches for managing pregnancy complications related to trophoblast dysfunction

    Lithium Expulsion from the Solid-State Electrolyte Li<sub>6.4</sub>La<sub>3</sub>Zr<sub>1.4</sub>Ta<sub>0.6</sub>O<sub>12</sub> by Controlled Electron Injection in a SEM

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    The garnet ionic conductor is one of the promising candidate electrolytes for all-solid-state secondary lithium batteries, thanks to its high lithium ion conductivity and good thermal and chemical stability. However, its microstructure is difficult to approach because it is very sensitive to the inquisitive electron beam. In this study based on a scanning electron microscope (SEM), we found that the electron beam expulses the lithium out of Li<sub>6.4</sub>La<sub>3</sub>Zr<sub>1.4</sub>Ta<sub>0.6</sub>O<sub>12</sub> (LLZTO), and the expulsed zone expands to where a stationary beam could extend and penetrate. The expulsion of metallic lithium was confirmed by its oxidation reaction after nitrogen inflow into the SEM. This phenomenon may provide us an effective probe to peer into the conductive nature of this electrolyte. A frame-scan scheme is employed to measure the expulsion rate by controllable and more uniform incidence of electrons. Lithium accumulation processes are continuously recorded and classified into four modes by fitting its growth behaviors into a dynamic equation that is mainly related to the initial ion concentration and ion migration rate in the electrolyte. These results open a novel possibility of using the SEM probe to gain dynamic information on ion migration and lithium metal growth in solid materials

    H3K27me3-modulated Hofbauer cell BMP2 signalling enhancement compensates for shallow trophoblast invasion in preeclampsiaResearch in context

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    Summary: Background: Preeclampsia (PE) is a common hypertensive pregnancy disorder associated with shallow trophoblast invasion. Although bone morphogenetic protein 2 (BMP2) has been shown to promote trophoblast invasion in vitro, its cellular origin and molecular regulation in placenta, as well as its potential role in PE, has yet to be established. Additionally, whether BMP2 and/or its downstream molecules could serve as potential diagnostic or therapeutic targets for PE has not been explored. Methods: Placentas and sera from PE and healthy pregnant women were subjected to multi-omics analyses, immunoblots, qPCR, and ELISA assays. Immortalized trophoblast cells, primary cultures of human trophoblasts, and first-trimester villous explants were used for in vitro experiments. Adenovirus expressing sFlt-1 (Ad Flt1)-induced PE rat model was used for in vivo studies. Findings: We find globally decreased H3K27me3 modifications and increased BMP2 signalling in preeclamptic placentas, which is negatively correlated with clinical manifestations. BMP2 is derived from Hofbauer cells and epigenetically regulated by H3K27me3 modification. BMP2 promotes trophoblast invasion and vascular mimicry by upregulating BMP6 via BMPR1A-SMAD2/3-SMAD4 signalling. BMP2 supplementation alleviates high blood pressure and fetal growth restriction phenotypes in Ad Flt1-induced rat PE model. Interpretation: Our findings demonstrate that epigenetically regulated Hofbauer cell-derived BMP2 signalling enhancement in late gestation could serve as a compensatory response for shallow trophoblast invasion in PE, suggesting opportunities for diagnostic marker and therapeutic target applications in PE clinical management. Funding: National Key Research and Development Program of China (2022YFC2702400), National Natural Science Foundation of China (82101784, 82171648, 31988101), and Natural Science Foundation of Shandong Province (ZR2020QH051, ZR2020MH039)

    Identification of circular RNAs and their alterations involved in developing male Xenopus laevis chronically exposed to atrazine

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    Atrazine (AZ) is an environmental endocrine disrupting chemical which can affect the development of amphibians. In our past studies, we demonstrated that chronical exposure to 100 μg/L AZ can cause abnormalities in development and related genes expression of gonads in developing male Xenopus laevis (X.\ua0laevis) tadpoles. Recent studies by others have demonstrated that circular RNAs (circRNAs) are implicated in multiple developmental anomalies. However, whether circRNAs involve in the effects in AZ-exposed X.\ua0laevis remains unknown. In this study, over 68575 circRNAs were detected by circRNA sequencing of testis tissues from control groups (n = 3) and AZ-treated X.\ua0laevis (n = 3). Treatment of AZ led to 405 circRNAs differentially expressed including 44 upregulated and 361 downregulated compared with froglets in the control groups. Two upregulated and 6 downregulated circRNAs were further validated by real-time PCR assay which displayed consistent regulation patterns as shown by the transcriptome sequencing results. Two hundreds and eighty two differentially expressed circRNAs played miRNA sponges roles. Kyoto Encyclopedia of Genes and Genomes pathway analysis of miRNA targets showed that AZ-affected circRNAs are mainly involved in 19 pathways. The Wnt signaling pathway and progesterone-mediated oocyte maturation pathway may be two involved signal pathways. This study for the first time provides evidence that AZ can alter circRNAs which play a role in AZ-induced testicular degeneration of developing male X.\ua0laevis through regulation of expressions of functional genes in the testes of X.\ua0laevis

    Validation and bioinformatics analysis of differentially expressed circRNAs involved in developing male Xenopus laevis chronically exposed to atrazine

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    The data presented here are related to the research article titled “Identification of circular RNAs and their alterations involved in developing male Xenopus laevis chronically exposed to atrazine” (Sai et al., 2018) [1]. Circular RNAs (circRNAs) are implicated in multiple developmental anomalies (Bachmayr-Heyda et al., 2015; Li et al., 2015) [2,3]. This report describes the differentially expressed circRNAs involved in developing male Xenopus laevis (X. laevis) chronically exposed to atrazine (AZ) database. The database contains the validation of differentially expressed circRNAs, KEGG analysis of differentially expressed circRNA-associated target genes and prediction of miRNA binding sites. These data may help to further evaluate the role of circRNAs in male X. laevis chronically exposed to AZ
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