111 research outputs found

    ST-YOLOA: a Swin-transformer-based YOLO model with an attention mechanism for SAR ship detection under complex background

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    A synthetic aperture radar (SAR) image is crucial for ship detection in computer vision. Due to the background clutter, pose variations, and scale changes, it is a challenge to construct a SAR ship detection model with low false-alarm rates and high accuracy. Therefore, this paper proposes a novel SAR ship detection model called ST-YOLOA. First, the Swin Transformer network architecture and coordinate attention (CA) model are embedded in the STCNet backbone network to enhance the feature extraction performance and capture global information. Second, we used the PANet path aggregation network with a residual structure to construct the feature pyramid to increase global feature extraction capability. Next, to cope with the local interference and semantic information loss problems, a novel up/down-sampling method is proposed. Finally, the decoupled detection head is used to achieve the predicted output of the target position and the boundary box to improve convergence speed and detection accuracy. To demonstrate the efficiency of the proposed method, we have constructed three SAR ship detection datasets: a norm test set (NTS), a complex test set (CTS), and a merged test set (MTS). The experimental results show that our ST-YOLOA achieved an accuracy of 97.37%, 75.69%, and 88.50% on the three datasets, respectively, superior to the effects of other state-of-the-art methods. Our ST-YOLOA performs favorably in complex scenarios, and the accuracy is 4.83% higher than YOLOX on the CTS. Moreover, ST-YOLOA achieves real-time detection with a speed of 21.4 FPS

    Using microneedle array electrodes for non-invasive electrophysiological signal acquisition and sensory feedback evoking

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    Introduction: Bidirectional transmission of information is needed to realize a closed-loop human-machine interaction (HMI), where electrophysiological signals are recorded for man-machine control and electrical stimulations are used for machine-man feedback. As a neural interface (NI) connecting man and machine, electrodes play an important role in HMI and their characteristics are critical for information transmission.Methods: In this work, we fabricated a kind of microneedle array electrodes (MAEs) by using a magnetization-induced self-assembly method, where microneedles with a length of 500–600 μm and a tip diameter of ∼20 μm were constructed on flexible substrates. Part of the needle length could penetrate through the subjects’ stratum corneum and reach the epidermis, but not touch the dermis, establishing a safe and direct communication pathway between external electrical circuit and internal peripheral nervous system.Results: The MAEs showed significantly lower and more stable electrode-skin interface impedance than the metal-based flat array electrodes (FAEs) in various testing scenarios, demonstrating their promising impedance characteristics. With the stable microneedle structure, MAEs exhibited an average SNR of EMG that is more than 30% higher than FAEs, and a motion-intention classification accuracy that is 10% higher than FAEs. The successful sensation evoking demonstrated the feasibility of the MAE-based electrical stimulation for sensory feedback, where a variety of natural and intuitive feelings were generated in the subjects and thereafter objectively verified through EEG analysis.Discussion: This work confirms the application potential of MAEs working as an effective NI, in both electrophysiological recording and electrical stimulation, which may provide a technique support for the development of HMI

    Pathogenicity and functional analysis of CFAP410 mutations causing cone-rod dystrophy with macular staphyloma

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    BackgroundCone-rod dystrophy (CORD) caused by pathogenic variants in CFAP410 is a very rare disease. The mechanisms by which the variants caused the disease remained largely unknown. CFAP410 pathogenic variants were identified in a cone-rod dystrophy with macular staphyloma patient. We explored the pathogenicity and performed functional analysis of two compound heterozygous mutations.MethodsA 6-year-old boy complained decreased vision for 1 year, underwent ocular examinations together with systemic X-ray check. Blood sample was taken for targeted next generation sequencing (Tg-NGS). Pathogenicity of identified variants was determined by ACMG guideline. Mutated plasmids were constructed and transferred to HEK293T cells. Cell cycle, protein stability, and protein ubiquitination level was measured.ResultsThe best-corrected visual acuity of proband was 0.20 bilaterally. Fundus showed macular staphyloma and uneven granular pigment disorder in the periphery of the retina. SS-OCT showed thinning and atrophy of the outer retina, residual ellipsoid zone (EZ) in the fovea. Scotopic and photopic ERG responses severe reduced. Two heterozygous missense pathogenic variants, c.319 T > C (p.Tyr107His) and c.347 C > T (p.Pro116Leu) in exon 4 of the CFAP410, were found and were pathogenic by the ACMG guideline. In vitro, pathogenic variants affect cell cycle. Immunofluorescence and western blotting showed that the mutant proteins decreased expression levels protein stability. Meanwhile, co-IP data suggested that ubiquitination level was altered in cells transferred with the mutated plasmids.ConclusionCompound heterozygous pathogenic variants c.319 T > C and c.347 C > T in CFAP410 caused CORD with macular staphyloma. The pathogenic mechanisms may be associated with alternations of protein stability and degradation through the ubiquitin-proteasome pathway

    An enzyme-sensitive probe for photoacoustic imaging and fluorescence detection of protease activity

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    A gold nanocage and dye conjugate has been demonstrated for use with photoacoustic imaging and fluorescence detection of protease activity. The detection sensitivity could be maximized by using gold nanocages with a localized surface plasmon resonance peak away from the emission peak of the dye. These hybrids can be potentially used as multimodal contrast agents for molecular imaging.NIH[DP1 OD000798, P30 CA91842]; NCI[R01 CA13852701]; Alvin J. Siteman Cancer Center at Barnes-Jewish Hospital; Washington University School of Medicine; China Scholarship Council; NSF[ECS-0335765

    Natural phage nanoparticle-mediated real-time immuno-PCR for ultrasensitive detection of protein marker

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    Key Laboratory Funding Scheme of Guangdong Provincial Government [2011A060901013]; National Scientific Foundation of China (NSFC) [31100723]Current immuno-PCR methods either use bare or nanostructured DNA as a reporter or combine phage display for antigen binding and reporting, however, they are often complex to carry out and lack universality. We present a novel and universal design of immuno-PCR termed natural phage nanoparticle-mediated real-time immuno-PCR

    Multicolor Combinatorial Probe Coding for Real-Time PCR

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    The target volume of multiplex real-time PCR assays is limited by the number of fluorescent dyes available and the number of fluorescence acquisition channels present in the PCR instrument. We hereby explored a probe labeling strategy that significantly increased the target volume of real-time PCR detection in one reaction. The labeling paradigm, termed “Multicolor Combinatorial Probe Coding” (MCPC), uses a limited number (n) of differently colored fluorophores in various combinations to label each probe, enabling one of 2n-1 genetic targets to be detected in one reaction. The proof-of-principle of MCPC was validated by identification of one of each possible 15 human papillomavirus types, which is the maximum target number theoretically detectable by MCPC with a 4-color channel instrument, in one reaction. MCPC was then improved from a one-primer-pair setting to a multiple-primer-pair format through Homo-Tag Assisted Non-Dimer (HAND) system to allow multiple primer pairs to be included in one reaction. This improvement was demonstrated via identification of one of the possible 10 foodborne pathogen candidates with 10 pairs of primers included in one reaction, which had limit of detection equivalent to the uniplex PCR. MCPC was further explored in detecting combined genotypes of five β-globin gene mutations where multiple targets were co-amplified. MCPC strategy could expand the scope of real-time PCR assays in applications which are unachievable by current labeling strategy

    MEIS2C and MEIS2D promote tumor progression via Wnt/β-catenin and hippo/YAP signaling in hepatocellular carcinoma

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    Abstract Background MEIS2 has been identified as one of the key transcription factors in the gene regulatory network in the development and pathogenesis of human cancers. Our study aims to identify the regulatory mechanisms of MEIS2 in hepatocellular carcinoma (HCC), which could be targeted to develop new therapeutic strategies. Methods The variation of MEIS2 levels were assayed in a cohort of HCC patients. The proliferation, clone-formation, migration, and invasion abilities of HCC cells were measured to analyze the effects of MEIS2C and MEIS2D (MEIS2C/D) knockdown with small hairpin RNAs in vitro and in vivo. Chromatin immunoprecipitation (ChIP) was performed to identify MEIS2 binding site. Immunoprecipitation and immunofluorescence assays were employed to detect proteins regulated by MEIS2. Results The expression of MEIS2C/D was increased in the HCC specimens when compared with the adjacent noncancerous liver (ANL) tissues. Moreover, MEIS2C/D expression negatively correlated with the prognosis of HCC patients. On the other hand, knockdown of MEIS2C/D could inhibit proliferation and diminish migration and invasion of hepatoma cells in vitro and in vivo. Mechanistically, MESI2C activated Wnt/β-catenin pathway in cooperation with Parafibromin (CDC73), while MEIS2D suppressed Hippo pathway by promoting YAP nuclear translocation via miR-1307-3p/LATS1 axis. Notably, CDC73 could directly either interact with MEIS2C/β-catenin or MEIS2D/YAP complex, depending on its tyrosine-phosphorylation status. Conclusions Our studies indicate that MEISC/D promote HCC development via Wnt/β-catenin and Hippo/YAP signaling pathways, highlighting the complex molecular network of MEIS2C/D in HCC pathogenesis. These results suggest that MEISC/D may serve as a potential novel therapeutic target for HCC.https://deepblue.lib.umich.edu/bitstream/2027.42/152244/1/13046_2019_Article_1417.pd

    Mechanisms of radiotherapy resistance and radiosensitization strategies for esophageal squamous cell carcinoma

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    Abstract Esophageal squamous cell carcinoma (ESCC) is the sixth most common cause of cancer-related mortality worldwide, with more than half of them occurred in China. Radiotherapy (RT) has been widely used for treating ESCC. However, radiation-induced DNA damage response (DDR) can promote the release of cytokines and chemokines, and triggers inflammatory reactions and changes in the tumor microenvironment (TME), thereby inhibiting the immune function and causing the invasion and metastasis of ESCC. Radioresistance is the major cause of disease progression and mortality in cancer, and it is associated with heterogeneity. Therefore, a better understanding of the radioresistance mechanisms may generate more reversal strategies to improve the cure rates and survival periods of ESCC patients. We mainly summarized the possible mechanisms of radioresistance in order to reveal new targets for ESCC therapy. Then we summarized and compared the current strategies to reverse radioresistance
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