10,934 research outputs found

    Aberrant posterior cingulate connectivity classify first-episode schizophrenia from controls: A machine learning study

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    Background Posterior cingulate cortex (PCC) is a key aspect of the default mode network (DMN). Aberrant PCC functional connectivity (FC) is implicated in schizophrenia, but the potential for PCC related changes as biological classifier of schizophrenia has not yet been evaluated. Methods We conducted a data-driven approach using resting-state functional MRI data to explore differences in PCC-based region- and voxel-wise FC patterns, to distinguish between patients with first-episode schizophrenia (FES) and demographically matched healthy controls (HC). Discriminative PCC FCs were selected via false discovery rate estimation. A gradient boosting classifier was trained and validated based on 100 FES vs. 93 HC. Subsequently, classification models were tested in an independent dataset of 87 FES patients and 80 HC using resting-state data acquired on a different MRI scanner. Results Patients with FES had reduced connectivity between PCC and frontal areas, left parahippocampal regions, left anterior cingulate cortex, and right inferior parietal lobule, but hyperconnectivity with left lateral temporal regions. Predictive voxel-wise clusters were similar to region-wise selected brain areas functionally connected with PCC in relation to discriminating FES from HC subject categories. Region-wise analysis of FCs yielded a relatively high predictive level for schizophrenia, with an average accuracy of 72.28% in the independent samples, while selected voxel-wise connectivity yielded an accuracy of 68.72%. Conclusion FES exhibited a pattern of both increased and decreased PCC-based connectivity, but was related to predominant hypoconnectivity between PCC and brain areas associated with DMN, that may be a useful differential feature revealing underpinnings of neuropathophysiology for schizophrenia

    Hamiltonian formalism in Friedmann cosmology and its quantization

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    We propose a Hamiltonian formalism for a generalized Friedmann-Roberson-Walker cosmology model in the presence of both a variable equation of state (EOS) parameter w(a)w(a) and a variable cosmological constant Λ(a)\Lambda(a), where aa is the scale factor. This Hamiltonian system containing 1 degree of freedom and without constraint, gives Friedmann equations as the equation of motion, which describes a mechanical system with a variable mass object moving in a potential field. After an appropriate transformation of the scale factor, this system can be further simplified to an object with constant mass moving in an effective potential field. In this framework, the Λ\Lambda cold dark matter model as the current standard model of cosmology corresponds to a harmonic oscillator. We further generalize this formalism to take into account the bulk viscosity and other cases. The Hamiltonian can be quantized straightforwardly, but this is different from the approach of the Wheeler-DeWitt equation in quantum cosmology.Comment: 7 pages, no figure; v2: matches the version accepted by PR

    Coherence controlled soliton interactions

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    We demonstrate theoretically and subsequently observe in experiment a novel type of soliton interaction when a pair of closely spaced spatial optical solitons as a whole is made partially incoherent. We explain how the character of the soliton interaction can be controlled by the total partial incoherence, and show a possibility to change the soliton interaction from attractive to repulsive, or vice versa, near a certain threshold in the coherence parameter.Comment: 4 pages, 4 figure

    Relative entropy of entanglement of a kind of two qubit entangled states

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    We in this paper strictly prove that some block diagonalizable two qubit entangled state with six none zero elements reaches its quantum relative entropy entanglement by the a separable state having the same matrix structure. The entangled state comprises local filtering result state as a special case.Comment: 5 page

    Preparation and thermal properties of mesoporous silica/phenolic resin nanocomposites via in situ polymerization

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    In order to enhance the adhesion between inorganic particles and polymer matrix, in this paper, the mesoporous silica SBA-15 material was synthesized by the sol-gel method. The surface of SBA-15 was modified using γ-glycidyloxypropyltrimethoxysilane (GOTMS) as a coupling agent, and then mesoporous silica/phenolic resin (SBA-15/PF) nanocomposites were prepared via in situ polymerization. The structural parameters and physical properties of SBA-15, SBA-15-GOTMS (SBA-15 surface treated using GOTMS as coupling agents) and E-SBA-15/PF (SBA-15/PF nanocomposites extracted using ethanol as solvent) were characterized by X-ray diffraction (XRD), N2 adsorption-desorption, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and thermogravimetric analysis (TGA). The thermal properties of the nanocomposites were studied by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The results demonstrated that the GOTMS were successfully grafted onto the surface of SBA-15, and chemical bonds between PF and SBA-15-GOTMS were formed after in situ polymerization. In addition, it is found that the in situ polymerization method has great effects on the textural parameters of SBA-15. The results also showed that the glass transition temperatures and thermal stability of the PF nanocomposites were obviously enhanced as compared with the pure PF at silica contents between 1–3 wt%, due to the uniform dispersion of the modified SBA-15 in the matrix

    Self-Contained Pedestrian Tracking During Normal Walking Using an Inertial/Magnetic Sensor Module

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    This paper proposes a novel self-contained pedestrian tracking method using a foot-mounted inertial and magnetic sensor module, which not only uses the traditional zero velocity updates, but also applies the stride information to further correct the acceleration double integration drifts and thus improves the tracking accuracy. In our method, a velocity control variable is designed in the process model, which is set to the average velocity derived from stride information in the swing (nonzero velocity) phases or zero in the stance (zero-velocity) phases. Stride-based position information is also derived as the pseudomeasurements to further improve the accuracy of the position estimates. An adaptive Kalman filter is then designed to fuse all the sensor information and pseudomeasurements. The proposed pedestrian tracking method has been extensively evaluated using experiments, including both short distance walking with different patterns and long distance walking performed indoors and outdoors, and have been shown to perform effectively for pedestrian tracking

    Monodispersed Bioactive Glass Nanoclusters with Ultralarge Pores and Intrinsic Exceptionally High miRNA Loading for Efficiently Enhancing Bone Regeneration

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    Bioactive glass nanoparticles (BGNs) have attracted much attention in drug delivery and bone tissue regeneration, due to the advantages including biodegradation, high bone‐bonding bioactivity, and facile large‐scale fabrication. However, the wide biomedical applications of BGNs such as efficient gene delivery are limited due to their poor pore structure and easy aggregation. Herein, for the first time, this study reports novel monodispersed bioactive glass nanoclusters (BGNCs) with ultralarge mesopores (10–30 nm) and excellent miRNA delivery for accelerating critical‐sized bone regeneration. BGNCs with different size (100–500 nm) are fabricated by using a branched polyethylenimine as the structure director and catalyst. BGNCs show an excellent apatite‐forming ability and high biocompatibility. Importantly, BGNCs demonstrate an almost 19 times higher miRNA loading than those of conventional BGNs. Additionally, BGNCs–miRNA nanocomplexes exhibit a significantly high antienzymolysis, enhance cellular uptake and miRNA transfection efficiency, overpassing BGNs and commercial Lipofectamine 3000. BGNCs‐mediated miRNA delivery significantly improves the osteogenic differentiation of bone marrow stromal stem cells in vitro and efficiently enhances bone formation in vivo. BGNCs can be a highly efficient nonviral vector for various gene therapy applications. The study may provide a novel strategy to develop highly gene‐activated bioactive nanomaterials for simultaneous tissue regeneration and disease therapy.Monodispersed bioactive glass nanoclusters (BGNCs) with ultra‐large mesopores (10–30 nm) are developed for miRNA delivery to enhance bone regeneration. BGNCs demonstrated an ultrahigh miRNA loading and transfection efficiency, overpassing commercial lipofectamine. BGNCs‐mediated miRNA delivery significantly improved osteogenic differentiation of bone marrow stromal stem cells in vitro and enhanced bone formation in vivo.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/139128/1/adhm201700630-sup-0001-S1.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/139128/2/adhm201700630.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/139128/3/adhm201700630_am.pd
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