77 research outputs found

    LBL: Logarithmic Barrier Loss Function for One-class Classification

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    One-class classification (OCC) aims to train a classifier only with the target class data and attracts great attention for its strong applicability in real-world application. Despite a lot of advances have been made in OCC, it still lacks the effective OCC loss functions for deep learning. In this paper, a novel logarithmic barrier function based OCC loss (LBL) that assigns large gradients to the margin samples and thus derives more compact hypersphere, is first proposed by approximating the OCC objective smoothly. But the optimization of LBL may be instability especially when samples lie on the boundary leading to the infinity loss. To address this issue, then, a unilateral relaxation Sigmoid function is introduced into LBL and a novel OCC loss named LBLSig is proposed. The LBLSig can be seen as the fusion of the mean square error (MSE) and the cross entropy (CE) and the optimization of LBLSig is smoother owing to the unilateral relaxation Sigmoid function. The effectiveness of the proposed LBL and LBLSig is experimentally demonstrated in comparisons with several state-of-the-art OCC algorithms on different network structures. The source code can be found at https://github.com/ML-HDU/LBL_LBLSig

    Woltjer-Taylor State Without Taylor's Conjecture - Plasma Relaxation at all Wavelengths

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    In astrophysical and laboratory plasmas, it has been discovered that plasmas relax towards the well-known Woltjer-Taylor state specified by βˆ‡ x B = Ξ±B for a constant Ξ± . To explain how such a relaxed state is reached, Taylor developed his famous relaxation theory based on the conjecture that the relaxation is dominated by short wavelength fluctuations. However, there is no conclusive experimental and numerical evidence to support Taylor's conjecture. A new theory is developed, which predicts that the system will evolve towards the Woltjer-Taylor state for an arbitrary fluctuation spectrum

    Use of Xinfeng capsule to treat abarticular pathologic changes in patients with rheumatoid arthritis

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    AbstractObjectiveTo observe the influence of Xinfeng-capsule (XFC) on abarticular pathologic changes (APCs) and other indices of patients with rheumatoid arthritis (RA) and explore the mechanism of action of XFC in improving such changes.MethodsThree-hundred RA patients were divided randomly into a treatment group (n=150) and control group (n=150). A normal control (NC) group (n=90) was also created. Changes in cardiac function, pulmonary function, anemia indices and platelet parameters of RA patients were measured. Curative effects of the two groups were compared, and comparison carried out with the NC group.ResultsIn 300 RA patients, late diastolic peak flow velocity (A peak) was much higher (P<0.01) and early diastolic peak flow velocity (E peak), E/A, and left ventricular fraction shortening much lower (P<0.01) than those in the NC group. Vital capacity (VC), forced vital capacity in one second, forced vital capacity (FVC), maximal voluntary ventilation (MVV), maximal expiratory flow in 50% of VC (FEF50) and FEF75 were lowered remarkably (P< 0.05 or P<0.01). Platelet count (PLT), plateletcrit (PCT) and mean platelet volume (MPV) increased markedly (P<0.05 or P<0.01), and hemoglobin (Hb) level decreased significantly (P<0.05). After XFC treatment, the A peak and PLT and PCT were much lower (P<0.05), and E/A and the number of red blood cells as well as Hb level were much higher (P< 0.05), as were FVC, MVV and FEF50 (P<0.05 or P< 0.01), in the treatment group than those in the NC group. Total score of pain and swelling in joints, uric-acid level and high-sensitivity C-reactive protein level were much lower, and superoxide dismutase level as well as the number of CD4 + CD25 + regulation T cells (Treg) and CD4 + CD25 + CD127-Treg were much higher (P<0.05 or P<0.01) in the treatment group than those in the NC group.ConclusionRA patients with pathologic changes in joints also suffer from lower cardiac and pulmonary functions and from parameters of anemia and platelet factors. XFC can improve the symptoms of RA patients, ameliorate their cardiac and pulmonary functions and reduce the parameters of anemia and platelet factors. XFC lowers the immune inflammatory reaction to improve APCs in RA patients

    Reactive Oxygen Species Released from Hypoxic Hepatocytes Regulates MMP-2 Expression in Hepatic Stellate Cells

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    Hypoxia is a common environmental stress factor and is associated with fibrogenesis. Matrix metalloproteinase-2 (MMP-2), produced by hepatic stellate cells (HSCs), plays an important role in liver fibrogenesis. However, inconsistent results have been reported on the impact of hypoxia on MMP-2 expression and activity in HSCs. We speculated that cell–cell interaction is involved in the regulation of MMP-2 expression and activity at low oxygen level in vivo. Therefore, in this report we investigated the mechanism by which hypoxic hepatocytes regulates MMP-2 expression in HSCs. Our results showed that the conditioned medium from hypoxia-treated rat hepatocytes strongly induced the expression of MMP-2 mRNA and protein in rat HSC-T6 cells. Reduced glutathione neutralized ROS released from hypoxic hepatocytes, leading to reduced MMP-2 expression in HSC-T6 cells. In addition, phospho-IΞΊB-Ξ± protein level was increased in HSC-T6 cells treated with hypoxia conditioned medium, and NF-ΞΊB signaling inhibitor inhibited MMP-2 expression in HSC-T6 cells. Taken together, our data suggest that ROS is an important factor released by hypoxic hepatocytes to regulate MMP-2 expression in HSCs, and NF-ΞΊB signaling is crucially involved in ROS-induced MMP-2 expression in HSCs. Our findings suggest that strategies aimed at antagonizing the generation of ROS in hypoxic hepatocytes and inhibiting NF-ΞΊB signaling in HSCs may represent novel therapeutic options for liver fibrosis

    Synaptic Neurotransmission Depression in Ventral Tegmental Dopamine Neurons and Cannabinoid-Associated Addictive Learning

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    Drug addiction is an association of compulsive drug use with long-term associative learning/memory. Multiple forms of learning/memory are primarily subserved by activity- or experience-dependent synaptic long-term potentiation (LTP) and long-term depression (LTD). Recent studies suggest LTP expression in locally activated glutamate synapses onto dopamine neurons (local Glu-DA synapses) of the midbrain ventral tegmental area (VTA) following a single or chronic exposure to many drugs of abuse, whereas a single exposure to cannabinoid did not significantly affect synaptic plasticity at these synapses. It is unknown whether chronic exposure of cannabis (marijuana or cannabinoids), the most commonly used illicit drug worldwide, induce LTP or LTD at these synapses. More importantly, whether such alterations in VTA synaptic plasticity causatively contribute to drug addictive behavior has not previously been addressed. Here we show in rats that chronic cannabinoid exposure activates VTA cannabinoid CB1 receptors to induce transient neurotransmission depression at VTA local Glu-DA synapses through activation of NMDA receptors and subsequent endocytosis of AMPA receptor GluR2 subunits. A GluR2-derived peptide blocks cannabinoid-induced VTA synaptic depression and conditioned place preference, i.e., learning to associate drug exposure with environmental cues. These data not only provide the first evidence, to our knowledge, that NMDA receptor-dependent synaptic depression at VTA dopamine circuitry requires GluR2 endocytosis, but also suggest an essential contribution of such synaptic depression to cannabinoid-associated addictive learning, in addition to pointing to novel pharmacological strategies for the treatment of cannabis addiction
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