76 research outputs found

    Dual-Context Aggregation for Universal Image Matting

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    Natural image matting aims to estimate the alpha matte of the foreground from a given image. Various approaches have been explored to address this problem, such as interactive matting methods that use guidance such as click or trimap, and automatic matting methods tailored to specific objects. However, existing matting methods are designed for specific objects or guidance, neglecting the common requirement of aggregating global and local contexts in image matting. As a result, these methods often encounter challenges in accurately identifying the foreground and generating precise boundaries, which limits their effectiveness in unforeseen scenarios. In this paper, we propose a simple and universal matting framework, named Dual-Context Aggregation Matting (DCAM), which enables robust image matting with arbitrary guidance or without guidance. Specifically, DCAM first adopts a semantic backbone network to extract low-level features and context features from the input image and guidance. Then, we introduce a dual-context aggregation network that incorporates global object aggregators and local appearance aggregators to iteratively refine the extracted context features. By performing both global contour segmentation and local boundary refinement, DCAM exhibits robustness to diverse types of guidance and objects. Finally, we adopt a matting decoder network to fuse the low-level features and the refined context features for alpha matte estimation. Experimental results on five matting datasets demonstrate that the proposed DCAM outperforms state-of-the-art matting methods in both automatic matting and interactive matting tasks, which highlights the strong universality and high performance of DCAM. The source code is available at \url{https://github.com/Windaway/DCAM}

    An innovative information fusion method with adaptive Kalman filter for integrated INS/GPS navigation of autonomous vehicles

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    Information fusion method of INS/GPS navigation system based on filtering technology is a research focus at present. In order to improve the precision of navigation information, a navigation technology based on Adaptive Kalman Filter with attenuation factor is proposed to restrain noise in this paper. The algorithm continuously updates the measurement noise variance and processes noise variance of the system by collecting the estimated and measured values, and this method can suppress white noise. Because a measured value closer to the current time would more accurately reflect the characteristics of the noise, an attenuation factor is introduced to increase the weight of the current value, in order to deal with the noise variance caused by environment disturbance. To validate the effectiveness of the proposed algorithm, a series of road tests are carried out in urban environment. The GPS and IMU data of the experiments were collected and processed by dSPACE and MATLAB/Simulink. Based on the test results, the accuracy of the proposed algorithm is 20% higher than that of a traditional Adaptive Kalman Filter. It also shows that the precision of the integrated navigation can be improved due to the reduction of the influence of environment noise

    An Efficacious Endometrial Sampler for Screening Endometrial Cancer

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    Recently, the research on early detection of precancerous change and endometrial carcinoma has been focusing on minimally invasive procedures for screening. On this basis, we aim to verify the feasibility of endometrial samplers for screening endometrial cancer using Li Brush. We recruited patients undergoing hysterectomy for different diseases from the Inpatient Department of the Department of Obstetrics and Gynecology. Before surgery, endometrial cells were collected by Li Brush. The cytopathologic diagnosis from Li Brush and the histopathologic diagnosis from hysterectomy in the same patient were compared to calculate sensitivity (Se), specificity (Sp), false-negative rate (FNR), false-positive rate (FPR), positive predictive value (PV+) %, and negative predictive value (PV-). The research enrolled 293 women into this self-controlled trial. According to the hypothesis test of paired four lattices, we obtained the following indicators: Se 92.73, Sp 98.15, FNR 7.27, FPR 1.85, PV+92.73, and PV−98.15%. The endometrial sampler Li Brush is an efficacious instrument for screening endometrial cancer

    Metadherin Contributes to the Pathogenesis of Diffuse Large B-cell Lymphoma

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    BACKGROUND: Metadherin (MTDH) has been demonstrated as a potentially crucial mediator of various types of human malignancies. However, the expression and role of MTDH in diffuse large-B-cell lymphoma (DLBCL) have not been reported yet. This study aimed to illuminate the role of MTDH in the pathogenesis of DLBCL. METHODOLOGY/PRINCIPAL FINDINGS: A remarkable elevation of MTDH on mRNA level was detected in DLBCL tissues by quantitative polymerase chain reaction (PCR). Using Western-blot analysis we found that the expression of MTDH protein was significantly upregulated in DLBCL cell lines and DLBCL tissues compared with peripheral blood mononuclear cells (PBMCs) from healthy samples and tissues from patients of reactive hyperplasia of lymph node. The results showed high expression of MTDH in 23 of 30 (76.67%) DLBCL tissues by using immunohistochemical analysis and the over expression of MTDH was strongly correlated to the clinical staging of patients with DLBCL (P<0.05). Furthermore, the finding suggested that the increase of MTDH in DLBCL cells could distinctly enhance cell proliferation and inhibit cell apoptosis; meanwhile, inhibition of MTDH expression by specific siRNA clearly enhanced LY8 cell apoptosis. Upregulation of MTDH elevated the protein level of total β-catenin and translocation of β-catenin to the nucleus directly or indirectly. Knockdown of MTDH decreased the level of total, cytoplasmic β-catenin and reduced nuclear accumulation of β-catenin protein. This indicated that the function of MTDH on the development of DLBCL was mediated through regulation of Wnt/β-catenin signaling pathway. CONCLUSIONS/SIGNIFICANCE: Our results suggest that MTDH contributes to the pathogenesis of DLBCL mediated by activation of Wnt/β-catenin pathway. This novel study may contribute to further investigation on the useful biomarkers and potential therapeutic target in the DLBCL patients

    The application value of a new Zn(II) coordination polymer in the early diagnosis and treatment of infantile rickets

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    771-775In the present study, a new 1D Zn(II) coordination polymer (CP) on the basis of 2,5-bis(pyridine-2-yl)-1,3,4-thiadiazole (L) as linking ligand with the chemical formula of [ZnLCl2]n has been created via blending L with Zn salt (ZnCl2) and studied through single crystal X-ray diffraction and elemental analysis. Its application values on the early diagnosis and treatment of infantile rickets were determined and the relevant mechanism was studied in the meanwhile. Then, the QCT was used to measure the bone density of the infantile rickets animal after adding compound. Moreover, the activity of the wnt signaling routine in the bone tissue was assessed via real time RT-PCR. By investigating into the detail of the binding conformation from a molecular level, molecular docking simulation reveals that the expected biological activity of the Zn complex comes from the pyridine group

    Preparation of Regular Cement Hydration Crystals and Ordered Microstructures by Doping GON and an Investigation into Its Compressive and Flexural Strengths

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    In this work, we found that by controlling the size of the graphene oxide nanosheets (GON) at 5–140 nm, 5–260 nm and 5–410 nm, respectively, we could prepare regular shaped cement hydration crystals with the shape of nano-needle-like, flower-like, and polyhedron-like crystals, respectively. Together, these crystals formed an ordered structure of cement composites on both the micro and macro levels, and the compressive and flexural strengths of the cement composites obviously increased when compared to the control samples. Our results indicated that the smallest structural unit of regular crystals was the nano-polyhedron-like crystals, which consisted of AFt, AFm, CH, and crystallization C–S–H, and could assemble into regular needle-like crystals, flower-like crystals, and polyhedron-like crystals, as well as an ordered structure on the micro and macro levels. Most of the C-S-H was transferred into a monoclinic system crystals and the remainder played the role of an adhesive in the forming process of regular crystals and structure. The cracks and holes in the cement composites disappeared by the self-repairing effect of the growing hydration crystal. The results indicate that ordered structural cement composites with defect-free structures and high strength can be prepared using GON with a suitable size range

    Study of Human Visual Comfort Based on Sudden Vertical Illuminance Changes

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    Rapid changes in vertical illuminance trigger visual fatigue. Therefore, controlling the illuminance ratio of adjacent spaces can ensure the satisfaction and comfort of users. This study takes reaction time as the measure of adaptation and explores the correlation between visual adaptation and comfort in different light environments. The Landolt C ring was selected as the visual standard for the experimental test, the degree of visual comfort was assessed using a Likert scale, and experimental parameters were formulated according to relevant criteria. By analyzing the subjective visual comfort, visual task performance and physiological evaluations of the participants under different changing illuminance levels, we have concluded that there is a significant correlation between reaction time and visual comfort, and no significant effect of gender on visual comfort. Therefore, under the condition of meeting the required value of illumination standard, the smaller the illuminance ratio of adjacent rooms, the more the comfort and visual acuity of users can be guaranteed, and visual fatigue can also be avoided. The study is a useful resource for improving comfort and pleasure in a light environment as well as for lighting design

    Fabrication of GO/Cement Composites by Incorporation of Few-Layered GO Nanosheets and Characterization of Their Crystal/Chemical Structure and Properties

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    Original graphene oxide (GO) nanosheets were prepared using the Hummers method and found to easily aggregate in aqueous and cement composites. Using carboxymethyl chitosan (CCS) as a dispersant, few-layered GO nanosheets (1–2 layers) were obtained by forming CCS/GO intercalation composites. The testing results indicated that the few-layered GO nanosheets could uniformly spread, both in aqueous and cement composites. The cement composites were prepared with GO dosages of 0.03%, 0.05% and 0.07% and we found that they had a compact microstructure in the whole volume. A special feature was determined, namely that the microstructures consisted of regular-shaped crystals created by self-crosslinking. The X-ray diffraction (XRD) results indicated that there was a higher number of cement hydration crystals in GO/cement composites. Meanwhile, we also found that partially-amorphous Calcium-Silicate-Hydrate (C-S-H) gel turned into monoclinic crystals. At 28 days, the GO/cement composites reached the maximum compressive and flexural strengths at a 0.05% dosage. These strengths were 176.64 and 31.67 MPa and, compared with control samples, their increased ratios were 64.87% and 149.73%, respectively. Durability parameters, such as penetration, freeze-thaw, carbonation, drying-shrinkage value and pore structure, showed marked improvement. The results indicated that it is possible to obtain cement composites with a compact microstructure and with high performances by introducing CCS/GO intercalation composites

    Baculovirus as an ideal radionuclide reporter gene vector: a new strategy for monitoring the fate of human stem cells in vivo.

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    PURPOSE: Radionuclide reporter gene imaging holds promise for non-invasive monitoring of transplanted stem cells. Thus, the feasibility of utilizing recombinant baculoviruses carrying the sodium iodide symporter (NIS) reporter gene in monitoring stem cell therapy by radionuclide imaging was explored in this study. METHODS: Recombinant baculoviruses carrying NIS and green fluorescent protein (GFP) reporter genes (Bac-NIS and Bac-GFP) were constructed and used to infect human induced pluripotent stem cells (hiPSCs), human embryonic stem cells (hESCs) and human umbilical cord blood mesenchymal stem cells (hUCB-MSCs). Infection efficiency, total fluorescence intensity and duration of transgene expression were determined by flow cytometry. Cytotoxicity/proliferative effects of baculovirus on hUCB-MSCs were assessed using CCK-8 assays. ¹²⁵I uptake and perchlorate inhibition assays were performed on Bac-NIS-infected hUCB-MSCs. Radionuclide imaging of mice transplanted with Bac-NIS-infected hUCB-MSCs was performed by NanoSPECT/CT imaging. RESULTS: Infection efficiencies of recombinant baculovirus in hESCs, hiPSCs and hUCB-MSCs increased with increasing MOIs (27.3%, 35.8% and 95.6%, respectively, at MOI = 800). Almost no cytotoxicity and only slight effects on hUCB-MSCs proliferation were observed. Obvious GFP expression (40.6%) remained at 8 days post-infection. The radioiodide was functionally accumulated by NIS gene products and specifically inhibited by perchlorate (ClO₄⁻). Radioiodide uptake, peaking at 30 min and gradually decreasing over time, significantly correlated with hUCB-MSCs cell number (R² = 0.994). Finally, radionuclide imaging showed Bac-NIS-infected hUCB-MSCs effectively accumulated radioiodide in vivo, which gradually weakened over time. CONCLUSION: Baculovirus as transgenic vector of radionuclide reporter gene imaging technology is a promising strategy for monitoring stem cell transplantation therapy
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