501 research outputs found

    Advances in diagnosis and non-surgical treatment of Bell's palsy

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    AbstractBell's palsy is a commonly seen cranial nerve disease and can result in compromised facial appearance and functions. Its etiology, prognosis and treatment are still being debated. This paper is a review of recent development in the understanding of etiology, diagnosis and non-surgical treatment of Bell's palsy

    Computational frameworks for homogenization and multiscale stability analyses of nonlinear periodic metamaterials

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    This paper presents a consistent computational framework for multiscale 1st order finite strain homogenization and stability analyses of rate-independent solids with periodic microstructures. Based on the principle of multiscale virtual power, the homogenization formulation is built on a priori discretized microstructure, and algorithms for computing the matrix representations of the homogenized stresses and tangent moduli are consistently derived. The homogenization results lose their validity at the onset of 1st bifurcation, which can be computed from multiscale stability analysis. The multiscale instabilities include: a) microscale structural instability which is calculated by Bloch wave analysis; and b) macroscale material instability which is calculated by rank-1 convexity checks on the homogenized tangent moduli. Details on the implementation of the Bloch wave analysis are provided, including the selection of the wave vector space and the retrieval of the real-valued buckling mode from the complex-valued Bloch wave. Three methods are detailed for solving the resulted constrained eigenvalue problem - two condensation methods and a null-space based projection method. Both implementations of the homogenization and stability analyses are validated using numerical examples including hyperelastic and elastoplastic metamaterials. Various microscale buckling phenomena are also demonstrated by examining several representative metamaterial examples. Aligned with theoretical results, the numerical results show that the microscopic long wavelength buckling can be equivalently detected by the loss of rank-1 convexity of the homogenized tangent moduli.Comment: 75 pages, 39 Figure

    Fine-grained fault recognition method for shaft orbit of rotary machine based on convolutional neural network

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    In the fault diagnosis of the shaft orbit of rotating machinery, there are few prejudgments about the severity of the faults, which is very important for fault repair. Therefore, a fine-grained recognition method is proposed to detect different severity faults by shaft orbit. Since different shaft orbits represent different type and different severity of faults, the convolutional neural network (CNN) is applied for identifying the shaft orbits to recognize the type and severity of the fault. The recognition rate of proposed fine-grained fault identification method is 97.96 % on the simulated shaft orbit database, and it takes only 0.31 milliseconds for the recognition of single sample. Experimental result indicated that the classification performance of the proposed method are better than the traditional machine learning models. Moreover, the method is applied for the identification of the measured shaft orbits of rotor with different degree of imbalance faults, and the testing accuracy of the experiments in measured shaft orbits is 97.14 %, which has verified the effectiveness of the proposed fine-grained fault recognition method

    Performance Analysis of RIS-assisted MIMO-OFDM Cellular Networks Based on Matern Cluster Processes

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    Reconfigurable Intelligent Surfaces (RIS) technology are a promising physical-layer candidate for sixth-generation (6G) cellular networks. This paper provides a system-level performance assessment of RIS-assisted multi-input multi-output (MIMO) cellular networks in terms of downlink coverage probability and ergodic rate. To capture the inherent randomness in the spatial deployments of both Base Stations (BSs) and RISs, we propose a new stochastic geometry model for such systems based on the Matern Cluster Process (MCP). This model consists in randomly distributed RISs around BSs, whose placement is according to a Poisson Point Process (PPP). The RISs provide the multipath diversity and the multiple antenna receiver provide the antenna diversity. The system is assumed to use the orthogonal frequency division multiplexing (OFDM) technique to modulate the former and employ the maximal ratio combining (MRC) technique at the receiver to exploit the latter. We show that the coverage probability and the ergodic rate can be evaluated when considering RISs operate as batched powerless beamformers. The resulting analytical expressions provide a generic methodology to evaluate the impact of key RIS-related parameters, such as the size of RIS and the density of nodes, on system level performance. Numerical evaluations of the analytical expressions and Monte-Carlo simulations jointly validate the proposed analytical approach and provide valuable insights into the design of future RIS-assisted radio cellular networks

    Age- and Sex-Related Changes in Fasting Plasma Glucose and Lipoprotein in Cynomolgus Monkeys

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    Background: The age-related dysfunction of glucose and lipid metabolism has a long-standing relationship with cardiovascular and neurodegenerative disease. However, the effects of metabolic dysfunction on men and women are different. Reasons for these sex differences remains unclear. Cynomolgus monkeys have been used, in the past, for the study of human metabolic diseases due to their biologically proximity to humans. Nevertheless, few studies to date have focused on both age- and sex-related differences in glucose and lipid metabolism. The present study was designed to specifically address these questions by using a large cohort of cynomolgus monkeys (N = 1,399) including 433 males and 966 females with ages ranging 4 to 24 years old. Methods: Fasting plasma glucose (FPG) and lipid parameters including total cholesterol (T-Cho), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) were measured. All these parameters were compared between ages and sexes. Results: Among the entire cohort, age was strongly correlated with levels of FPG, TG and HDL. Consequently, sex-related analysis revealed that females had significantly higher average levels of FPG, T-Cho, TG, HDL-C and LDL-C than their male counterparts. In addition, more female (28.5 %) than male (16 %) monkeys qualified for impaired fasting plasma glucose (IFPG). In those IFPG animals, sex-related differences were also detected i.e. females had significantly increased levels of T-Cho, TG and LDL-C. Conclusions: The result, for the first time, demonstrated the similarities and differences in detail between male and female cynomolgus monkeys in relationship to age-related glucose and lipoprotein metabolisms, and differences under various physiological conditions. The detailed glucose and lipoprotein profiling should provide additional and important insights for prediabetic conditions. Cynomolgus monkeys appear to be an excellent model for translational research of diabetes and for novel therapeutic strategies testing to overt diabetes

    Bis{1-[4-(benz­yloxy)phen­yl]-4,4,4-tri­fluoro­butane-1,3-dionato(1−)}dipyri­dine­cobalt(II)

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    In the title compound, [Co(C17H12F3O3)2(C5H5N)2], the CoII ion is situated on a twofold rotation axis, coordinated by four O atoms from two 1-[4-(benz­yloxy)phen­yl]-4,4,4-trifluoro­butane-1,3-dionate(1−) (L) ligands and two N atoms from two pyridine ligands in a distorted octa­hedral geometry. The two pyridine rings form a dihedral angle of 84.63 (7)°. The two benzene rings in L are twisted at 58.83 (5)°. Weak inter­molecular C—H⋯F hydrogen bonds consolidate the crystal packing
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