436 research outputs found

    Graph-Based Decoding Model for Functional Alignment of Unaligned fMRI Data

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    Aggregating multi-subject functional magnetic resonance imaging (fMRI) data is indispensable for generating valid and general inferences from patterns distributed across human brains. The disparities in anatomical structures and functional topographies of human brains warrant aligning fMRI data across subjects. However, the existing functional alignment methods cannot handle well various kinds of fMRI datasets today, especially when they are not temporally-aligned, i.e., some of the subjects probably lack the responses to some stimuli, or different subjects might follow different sequences of stimuli. In this paper, a cross-subject graph that depicts the (dis)similarities between samples across subjects is used as a priori for developing a more flexible framework that suits an assortment of fMRI datasets. However, the high dimension of fMRI data and the use of multiple subjects makes the crude framework time-consuming or unpractical. To address this issue, we further regularize the framework, so that a novel feasible kernel-based optimization, which permits nonlinear feature extraction, could be theoretically developed. Specifically, a low-dimension assumption is imposed on each new feature space to avoid overfitting caused by the highspatial-low-temporal resolution of fMRI data. Experimental results on five datasets suggest that the proposed method is not only superior to several state-of-the-art methods on temporally-aligned fMRI data, but also suitable for dealing `with temporally-unaligned fMRI data.Comment: 17 pages, 10 figures, Proceedings of the Association for the Advancement of Artificial Intelligence (AAAI-20

    Roles of circulating soluble interleukin (IL)-6 receptor and IL-6 receptor expression on CD4+ T cells in patients with chronic hepatitis B

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    SummaryObjectivesThe objective of this study was to investigate the potential clinical roles of circulating soluble interleukin (IL)-6 receptor (sIL-6R) and IL-6R expression on CD4+ T cells (CD4+ IL-6R+ T cells) in chronic hepatitis B (CHB) patients.MethodsOne hundred and thirty-three subjects, including 72 CHB patients, 27 asymptomatic carriers, eight acute hepatitis B (AHB) patients, and 26 healthy donors were included in this study. Plasma IL-6 and sIL-6R levels were measured by enzyme-linked immunosorbent assay (ELISA); the frequency of CD4+ IL-6R+ T cells was detected by flow cytometry analysis.ResultsOur data showed a significant increase in plasma sIL-6R levels and the frequency of CD4+ IL-6R+ T cells in peripheral blood in CHB patients compared to asymptomatic carriers and healthy controls (both p<0.05). The elevated prevalence of CD4+ IL-6R+ T cells was positively associated with increased serum alanine aminotransferase levels in CHB patients (r = 0.316, p = 0.007), but was not correlated with serum hepatitis B virus (HBV) DNA load. Moreover, CHB patients with an HBV DNA load >1.0×106 copies/ml had a lower level of plasma sIL-6R than those with an HBV DNA load <1.0×106 copies/ml.ConclusionsCirculating sIL-6R and CD4+ IL-6R+ T cells were increased in CHB patients. Elevated plasma sIL-6R is probably associated with HBV elimination, and CD4+ IL-6R+ T cells in peripheral blood might contribute to the pathogenesis of liver injury in CHB patients

    Numerical simulation of ultra-strength concrete-filled steel columns

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    Researches into the constitutive relation of the super high strength and high performance concrete and the stress strain relationship of the ultra-strength concrete-filled steel columns are rare. Therefore, this paper based on continuous mechanics presents the relationship of mathematical description to the concrete deformation behaviors. The compressive behaviors of steel-reinforced super high-strength concrete columns under axial loading were studied with a series of experiments. Two specimens with concrete strengths ranging from 130,1MPa to 137,3MPa and with 121mm circular hollow stub columns with wall thicknesses of 5 mm were manufactured. At the same time, a three dimensional non-linear FE analysis of axial compression was conducted using the finite element program ABAQUS/Standard solver. The numerical results were validated through comparison with experimental data in terms of axial loading and deformation modes

    Label-aligned multi-task feature learning for multimodal classification of Alzheimer’s disease and mild cognitive impairment

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    Multimodal classification methods using different modalities of imaging and non-imaging data have recently shown great advantages over traditional single-modality-based ones for diagnosis and prognosis of Alzheimer’s disease (AD), as well as its prodromal stage, i.e., mild cognitive impairment (MCI). However, to the best of our knowledge, most existing methods focus on mining the relationship across multiple modalities of the same subjects, while ignoring the potentially useful relationship across different subjects. Accordingly, in this paper, we propose a novel learning method for multimodal classification of AD/MCI, by fully exploring the relationships across both modalities and subjects. Specifically, our proposed method includes two subsequent components, i.e., label-aligned multi-task feature selection and multimodal classification. In the first step, the feature selection learning from multiple modalities are treated as different learning tasks and a group sparsity regularizer is imposed to jointly select a subset of relevant features. Furthermore, to utilize the discriminative information among labeled subjects, a new label-aligned regularization term is added into the objective function of standard multi-task feature selection, where label-alignment means that all multi-modality subjects with the same class labels should be closer in the new feature-reduced space. In the second step, a multi-kernel support vector machine (SVM) is adopted to fuse the selected features from multi-modality data for final classification. To validate our method, we perform experiments on the Alzheimer’s Disease Neuroimaging Initiative (ADNI) database using baseline MRI and FDG-PET imaging data. The experimental results demonstrate that our proposed method achieves better classification performance compared with several state-of-the-art methods for multimodal classification of AD/MCI

    Bacterium-Enabled Transient Gene Activation by Artificial Transcription Factor for Resolving Gene Regulation in Maize

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    Cellular functions are diversified through intricate transcription regulations, and an understanding gene regulation networks is essential to elucidating many developmental processes and environmental responses. Here, we employed the Transcriptional-Activator Like effectors (TALes), which represent a family of transcription factors that are synthesized by members of the Îł-proteobacterium genus Xanthomonas and secreted to host cells for activation of targeted host genes. Through delivery by the maize pathogen, Xanthomonas vasicola pv. vasculorum, designer TALes (dTALes), which are synthetic TALes, were used to induce the expression of the maize gene glossy3 (gl3), a MYB transcription factor gene involved in the cuticular wax biosynthesis. RNA-Seq analysis of leaf samples identified 146 gl3 downstream genes. Eight of the nine known genes known to be involved in the cuticular wax biosynthesis were up-regulated by at least one dTALe. A top-down Gaussian graphical model predicted that 68 gl3 downstream genes were directly regulated by GL3. A chemically induced mutant of the gene Zm00001d017418 from the gl3 downstream gene, encoding aldehyde dehydrogenase, exhibited a typical glossy leaf phenotype and reduced epicuticular waxes. The bacterial protein delivery of artificial transcription factors, dTALes, proved to be a straightforward and powerful approach for the revelation of gene regulation in plants

    Harnessing type I and type III CRISPR-Cas systems for genome editing

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    CRISPR-Cas (clustered regularly interspaced short palindromic repeats-CRISPR-associated) systems are widespread in archaea and bacteria, and research on their molecular mechanisms has led to the development of genome-editing techniques based on a few Type II systems. However, there has not been any report on harnessing a Type I or Type III system for genome editing. Here, a method was developed to repurpose both CRISPR-Cas systems for genetic manipulation in Sulfolobus islandicus, a thermophilic archaeon. A novel type of genome-editing plasmid (pGE) was constructed, carrying an artificial mini-CRISPR array and a donor DNA containing a non-target sequence. Transformation of a pGE plasmid would yield two alternative fates to transformed cells: wild-type cells are to be targeted for chromosomal DNA degradation, leading to cell death, whereas those carrying the mutant gene would survive the cell killing and selectively retained as transformants. Using this strategy, different types of mutation were generated, including deletion, insertion and point mutations. We envision this method is readily applicable to different bacteria and archaea that carry an active CRISPR-Cas system of DNA interference provided the protospacer adjacent motif (PAM) of an uncharacterized PAM-dependent CRISPR-Cas system can be predicted by bioinformatic analysis

    Elevated IL-6 Receptor Expression on CD4+ T Cells contributes to the increased Th17 Responses in patients with Chronic Hepatitis B

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    <p>Abstract</p> <p>Background</p> <p>Increased numbers of Interleukin-17-producing CD4<sup>+ </sup>T cells (Th17) have been found in association with hepatitis B virus (HBV)-induced liver injury. However, the mechanism underlying the increase of Th17 responses in patients with HBV infection remains unclear. In this study, we investigate the possible regulatory mechanisms of increased Th17 responses in patients with chronic hepatitis B(CHB).</p> <p>Methods</p> <p>Th17 response and IL-6R expression on CD4<sup>+ </sup>T cells in peripheral blood samples were determined by flow cytometry. Cytokines TGF-β, IL-1β, IL-6 and IL-17 in plasma and/or supernatant samples were determined by ELISA and the IL-17 and IL-6R mRNA levels were quantified by quantitative real-time reverse polymerase chain reaction.</p> <p>Results</p> <p>All these data indicated that the frequency of periphery Th17 cells is significantly correlated with the percentage of CD4<b><sup>+ </sup></b>T cells expressing IL-6R in CHB patients. CD4<sup>+ </sup>T cells from patients with CHB, but not those from healthy donors, produced higher levels of IL-17 and had more IL-6R expression upon stimulation with the HBV core antigen (HBcAg) in vitro. The PMA/ionomycin and HBcAg -stimulated up-regulation of IL-17 production by CD4<sup>+ </sup>T cells could be reversed by a neutralizing antibody against IL-6R.</p> <p>Conclusion</p> <p>we showed that enhancement of IL-6R expression on CD4<sup>+ </sup>T cells upon HBV infection contributes to increased Th17 response in patients with CHB.</p

    MicroRNA-483 amelioration of experimental pulmonary hypertension.

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    Endothelial dysfunction is critically involved in the pathogenesis of pulmonary arterial hypertension (PAH) and that exogenously administered microRNA may be of therapeutic benefit. Lower levels of miR-483 were found in serum from patients with idiopathic pulmonary arterial hypertension (IPAH), particularly those with more severe disease. RNA-seq and bioinformatics analyses showed that miR-483 targets several PAH-related genes, including transforming growth factor-β (TGF-β), TGF-β receptor 2 (TGFBR2), β-catenin, connective tissue growth factor (CTGF), interleukin-1β (IL-1β), and endothelin-1 (ET-1). Overexpression of miR-483 in ECs inhibited inflammatory and fibrogenic responses, revealed by the decreased expression of TGF-β, TGFBR2, β-catenin, CTGF, IL-1β, and ET-1. In contrast, inhibition of miR-483 increased these genes in ECs. Rats with EC-specific miR-483 overexpression exhibited ameliorated pulmonary hypertension (PH) and reduced right ventricular hypertrophy on challenge with monocrotaline (MCT) or Sugen + hypoxia. A reversal effect was observed in rats that received MCT with inhaled lentivirus overexpressing miR-483. These results indicate that PAH is associated with a reduced level of miR-483 and that miR-483 might reduce experimental PH by inhibition of multiple adverse responses
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