2,403 research outputs found

    Development of Bionic Air Cooler Used in High Temperature Coal Mine

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    In high temperature coal mine, the surface air cooler heat exchange efficiency decreases greatly because of high humidity and dust. In order to improve the heat exchange efficiency, the surface of the air cooler needs to be designed to reduce the dust adhesion, and improve the heat exchange efficiency. Based on the self-cleaning effect of lotus leaf, the surface of air cooler is designed and fin and tube are processed into the constructure of lotus leaf surface. With Ansys, the cooling effect of air cooler is simulated, and the experiment is done to test the heat exchange effect of the common air cooler and bionic air cooler in lab. By analysis, it can be concluded that the surface of bionic air cooler has the function of self-cleaning, and the structure can increase the heat exchange efficiency, which is higher above 30% than that of common air cooler. Key words: High temperature coal mine; Air cooler; Self-cleaning; Heat exchange efficienc

    3-Hy­droxy-1,2-dimeth­oxyxanthone

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    The title compound (systematic name: 3-hy­droxy-1,2-dimeth­oxy-9H-xanthen-9-one), C15H12O5, was isolated from Polygala arillata. The tricyclic unit is essentially planar (r.m.s. deviation = 0.039 Å). In the crystal, the mol­ecules form stacks along the a axis. Inter­molecular O—H⋯O hydrogen bonds link the mol­ecules into chains parallel to [010]

    MRI characterization of inflammatory myofibroblastic tumors in the maxillofacial region

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    PURPOSEWe aimed to investigate the magnetic resonance imaging (MRI) appearance of inflammatory myofibroblastic tumors (IMTs) in the maxillofacial region in order to improve diagnostic quality and resection efficacy.MATERIALS AND METHODSTen cases of pathologically identified IMTs were analyzed by MRI. The MRI features were examined, including tumor location, tumor shape, tumor margins, and involvement of the surrounding tissues.RESULTSOf ten masses investigated in this study, eight masses were irregular neoplasms with unclear margins and two masses, in the parotid gland, were regular neoplasms with clear margins. Precontrast T1-weighted images of all ten masses exhibited isointense signals compared to the adjacent tissue, while contrast-enhanced T1-weighted images showed strong enhancement. Six masses were hypointense and four masses were slightly hyperintense in T2-weighted images. Involvement of the adjacent structures was observed in eight of ten cases. Meanwhile, two patients experienced intracranial involvement.CONCLUSIONIMTs are rare tumors in the maxillofacial region, displaying a number of distinct MRI characteristics. Most importantly, they display low T2 signal intensity and strong enhancement, and they frequently invade surrounding structures. Thus, MRI can improve the accuracy of IMT diagnoses and provide critical information for surgical planning

    Seroprevalence of Toxoplasma gondii infection in dairy goats in Shaanxi Province, Northwestern China

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    <p>Abstract</p> <p>Background</p> <p><it>Toxoplasma gondii </it>is an important zoonotic pathogen causing significant human and animal health problems. Infection in dairy goats not only results in significant reproductive losses, but also represents an important source of human infection due to consumption of infected meat and milk. In the present study we report for the first time seroprevalence of <it>T. gondii </it>infection in Guanzhong and Saanen dairy goats in Shaanxi province, Northwestern China.</p> <p>Results</p> <p>Sera from 751 dairy goats from 9 farms in 6 counties were examined for <it>T. gondii </it>antibodies with an indirect haemagglutination (IHA) test. Antibodies to <it>T. gondii </it>were detected in 106 (14.1%) serum samples, with antibody titres ranging from 1:64 to 1:1024. Seropositive goats were found in all 9 farms and seroprevalences in Guanzhong (16.3%, 75/461) and Saanen (10.7%, 31/290) dairy goats were not statistically significantly different. All the factors (sex, age and location) reported in the present study affected prevalence of infection, and seroprevalence increased with age, suggesting postnatal acquisition of <it>T. gondii </it>infection.</p> <p>Conclusions</p> <p>The results of the present survey indicate that infection by <it>T. gondii </it>is widely prevalent in dairy goats in Shaanxi province, Northwestern China, and this has implications for prevention and control of toxoplasmosis in this province.</p

    A role for the cerebellum in motor-triggered alleviation of anxiety

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    Physical exercise is known to reduce anxiety, but the underlying brain mechanisms remain unclear. Here, we explore a hypothalamo-cerebello-amygdalar circuit that may mediate motor-dependent alleviation of anxiety. This three-neuron loop, in which the cerebellar dentate nucleus takes center stage, bridges the motor system with the emotional system. Subjecting animals to a constant rotarod engages glutamatergic cerebellar dentate neurons that drive PKCδ+ amygdalar neurons to elicit an anxiolytic effect. Moreover, challenging animals on an accelerated rather than a constant rotarod engages hypothalamic neurons that provide a superimposed anxiolytic effect via an orexinergic projection to the dentate neurons that activate the amygdala. Our findings reveal a cerebello-limbic pathway that may contribute to motor-triggered alleviation of anxiety and that may be optimally exploited during challenging physical exercise.</p

    Inverse Modeling for MEG/EEG data

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    We provide an overview of the state-of-the-art for mathematical methods that are used to reconstruct brain activity from neurophysiological data. After a brief introduction on the mathematics of the forward problem, we discuss standard and recently proposed regularization methods, as well as Monte Carlo techniques for Bayesian inference. We classify the inverse methods based on the underlying source model, and discuss advantages and disadvantages. Finally we describe an application to the pre-surgical evaluation of epileptic patients.Comment: 15 pages, 1 figur
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