282 research outputs found

    Motor Imagery Classification Based on Bilinear Sub-Manifold Learning of Symmetric Positive-Definite Matrices

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    In motor imagery brain-computer interfaces (BCIs), the symmetric positive-definite (SPD) covariance matrices of electroencephalogram (EEG) signals carry important discriminative information. In this paper, we intend to classify motor imagery EEG signals by exploiting the fact that the space of SPD matrices endowed with Riemannian distance is a high-dimensional Riemannian manifold. To alleviate the overfitting and heavy computation problems associated with conventional classification methods on high-dimensional manifold, we propose a framework for intrinsic sub-manifold learning from a high-dimensional Riemannian manifold. Considering a special case of SPD space, a simple yet efficient bilinear sub-manifold learning (BSML) algorithm is derived to learn the intrinsic sub-manifold by identifying a bilinear mapping that maximizes the preservation of the local geometry and global structure of the original manifold. Two BSML-based classification algorithms are further proposed to classify the data on a learned intrinsic sub-manifold. Experimental evaluation of the classification of EEG revealed that the BSML method extracts the intrinsic sub-manifold approximately 5× faster and with higher classification accuracy compared with competing algorithms. The BSML also exhibited strong robustness against a small training dataset, which often occurs in BCI studies

    A tunable radiation source by coupling laser-plasma-generated electrons to a periodic structure

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    Near-infrared radiation around 1000 nm generated from the interaction of a high-density MeV electron beam, obtained by impinging an intense ultrashort laser pulse on a solid target, with a metal grating is observed experimentally. Theoretical modeling and particle-in-cell simulation suggest that the radiation is caused by the Smith-Purcell mechanism. The results here indicate that tunable terahertz radiation with tens GV=m field strength can be achieved by using appropriate grating parameter

    Polymorphisms of exon 5, exon 7 and intron 10 of MMP2 gene and their association with wool density in Rex rabbits

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    [EN] Wool density is an important index that influences Rex rabbit fur quality. In our earlier studies, we found some important differentially expressed genes in different wool density of Rex rabbit by cDNA microarray. Based on the outcome, we conducted an association study to identify single nucleotide polymorphisms (SNPs) of exon 1, 5, 7 and 10 of matrix metalloproteinase-2 (MMP2) gene and their ligands associated with wool density. The results showed that exon 1 and exon 10 of MMP2 gene did not occur mutation in 100 Rex rabbits, meanwhile 3 SNPs were identified in exon 5, exon 7 and intron 10 of MMP2 gene sequence respectively, the 3 mutation sites were as follows: MMP2-exon 5-26C/G, MMP2-exon 7-101C/T and MMP2-intron 10-6C/T. The 3 SNPs were all in Hardy-Weinberg equilibrium. Phenotypic correlation analysis results showed the 3 mutations lacked significant associations (P>0.05) with the wool density.This work was supported by Natural Science Foundation Projects from Hebei Province of P.R.China (#C2014204019) and the Science and Technology Research Projects in Colleges from Hebei Province of P.R.China (#bj2014035).Chen, S.; Liu, Y.; Liu, T.; Chen, B.; Gu, Z. (2017). Polymorphisms of exon 5, exon 7 and intron 10 of MMP2 gene and their association with wool density in Rex rabbits. World Rabbit Science. 25(2):181-184. https://doi.org/10.4995/wrs.2017.6514SWORD18118425

    Enhancing anti-tumor immunity through liposomal oxaliplatin and localized immunotherapy via STING activation

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    The cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING) pathway is a promising approach for anti-cancer immunotherapy by bridging innate and adaptive immunity. Recent evidence suggests that chemotherapy-induced DNA damage can directly induce dendritic cell (DC) maturation and recruitment, which synergizes with STING activation to enhance anti-tumor effects. As an immunogenic cell death (ICD) inducer, oxaliplatin generates massive double-stranded DNA (dsDNA) crosslinks, release of tumor-associated antigens and promoting the "eat me" signal. STING activation improves antigen immunogenicity, which can promote T cell activation and infiltration. In this study, we developed liposomes encapsulating oxaliplatin and combine this formulation with a STING agonist (ADU-S100) for treating colorectal cancer. The liposomes efficiently inhibited the proliferation of tumor cells while induced ICD in CT26 colorectal cancer cells, which enhanced dendritic cell maturation and phagocytosis in vitro. The liposome-based immunochemotherapy exhibited the strongest efficacy, resulting in complete remission upon tumor inoculation. Mechanistic studies showed this potent anti-cancer effect was related to the significant recruitment of infiltrating CD8 and CD4 T cells, reduction of suppressive Treg cells, and a shift in the phenotype of tumor-associated suppressive macrophages that promote cancer to immune stimulating macrophages. Thus, our study demonstrated the potential of combining oxaliplatin-loaded liposomes with a STING agonist to reduce tumor growth by regulating the immunosuppressive state in the tumor.Horizon 2020 (H2020)777682TumorimmunologyRadiolog

    Effective combination of liposome-targeted chemotherapy and PD-L1 blockade of murine colon cancer

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    Therapeutic cancer drug efficacy can be limited by insufficient tumor penetration, rapid clearance, systemic toxicity and (acquired) drug resistance. The poor therapeutic index due to inefficient drug penetration and rapid drug clearance and toxicity can be improved by using a liposomal platform. Drug resistance for instance against pemetrexed, can be reduced by combination with docetaxel. Here, we developed a specific liposomal formulation to simultaneously deliver docetaxel and pemetrexed to enhance efficacy and safety. Hydrophobic docetaxel and hydrophilic pemetrexed were co-encapsulated into pH-sensitive liposomes using a thin-film hydration method with high efficiency. The physicochemical properties, toxicity, and immunological effects of liposomes were examined in vitro. Biodistribution, anti-tumor efficacy, and systemic immune response were evaluated in vivo in combination with PD-L1 immune checkpoint therapy using two murine colon cancer models. In cellular experiments, the liposomes exhibited strong cytotoxicity and induced immunogenic cell death. In vivo, the treatment with the liposome-based drug combination inhibited tumor development and stimulated immune responses. Liposomal encapsulation significantly reduced systemic toxicity compared to the delivery of the free drug. Tumor control was strongly enhanced when combined with anti-PDL1 immunotherapy in immunocompetent mice carrying syngeneic MC38 or CT26 colon tumors. We showed that treatment with liposome-mediated chemotherapy of docetaxel and pemetrexed combined with anti-PD-L1 immunotherapy is a promising strategy for the treatment of colon cancers.Horizon 2020 (H2020

    History and Applications of Dust Devil Studies

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    Studies of dust devils, and their impact on society, are reviewed. Dust devils have been noted since antiquity, and have been documented in many countries, as well as on the planet Mars. As time-variable vortex entities, they have become a cultural motif. Three major stimuli of dust devil research are identified, nuclear testing, terrestrial climate studies, and perhaps most significantly, Mars research. Dust devils present an occasional safety hazard to light structures and have caused several deaths

    Measurements of the observed cross sections for e+ee^+e^-\to exclusive light hadrons containing π0π0\pi^0\pi^0 at s=3.773\sqrt s= 3.773, 3.650 and 3.6648 GeV

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    By analyzing the data sets of 17.3, 6.5 and 1.0 pb1^{-1} taken, respectively, at s=3.773\sqrt s= 3.773, 3.650 and 3.6648 GeV with the BES-II detector at the BEPC collider, we measure the observed cross sections for e+eπ+ππ0π0e^+e^-\to \pi^+\pi^-\pi^0\pi^0, K+Kπ0π0K^+K^-\pi^0\pi^0, 2(π+ππ0)2(\pi^+\pi^-\pi^0), K+Kπ+ππ0π0K^+K^-\pi^+\pi^-\pi^0\pi^0 and 3(π+π)π0π03(\pi^+\pi^-)\pi^0\pi^0 at the three energy points. Based on these cross sections we set the upper limits on the observed cross sections and the branching fractions for ψ(3770)\psi(3770) decay into these final states at 90% C.L..Comment: 7 pages, 2 figure

    Partial wave analysis of J/\psi \to \gamma \phi \phi

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    Using 5.8×107J/ψ5.8 \times 10^7 J/\psi events collected in the BESII detector, the radiative decay J/ψγϕϕγK+KKS0KL0J/\psi \to \gamma \phi \phi \to \gamma K^+ K^- K^0_S K^0_L is studied. The ϕϕ\phi\phi invariant mass distribution exhibits a near-threshold enhancement that peaks around 2.24 GeV/c2c^{2}. A partial wave analysis shows that the structure is dominated by a 0+0^{-+} state (η(2225)\eta(2225)) with a mass of 2.240.02+0.030.02+0.032.24^{+0.03}_{-0.02}{}^{+0.03}_{-0.02} GeV/c2c^{2} and a width of 0.19±0.030.04+0.060.19 \pm 0.03^{+0.06}_{-0.04} GeV/c2c^{2}. The product branching fraction is: Br(J/ψγη(2225))Br(η(2225)ϕϕ)=(4.4±0.4±0.8)×104Br(J/\psi \to \gamma \eta(2225))\cdot Br(\eta(2225)\to \phi\phi) = (4.4 \pm 0.4 \pm 0.8)\times 10^{-4}.Comment: 11 pages, 4 figures. corrected proof for journa

    Direct Measurements of Absolute Branching Fractions for D0 and D+ Inclusive Semimuonic Decays

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    By analyzing about 33 pb1\rm pb^{-1} data sample collected at and around 3.773 GeV with the BES-II detector at the BEPC collider, we directly measure the branching fractions for the neutral and charged DD inclusive semimuonic decays to be BF(D0μ+X)=(6.8±1.5±0.7)BF(D^0 \to \mu^+ X) =(6.8\pm 1.5\pm 0.7)% and BF(D+μ+X)=(17.6±2.7±1.8)BF(D^+ \to \mu^+ X) =(17.6 \pm 2.7 \pm 1.8)%, and determine the ratio of the two branching fractions to be BF(D+μ+X)BF(D0μ+X)=2.59±0.70±0.25\frac{BF(D^+ \to \mu^+ X)}{BF(D^0 \to \mu^+ X)}=2.59\pm 0.70 \pm 0.25
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