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In the chronic disease diagnosis with high-dimensional clinical features, feature selection (FS) algorithms are widely applied to avoid sparse data. In current FS algorithms, only population features, which are in strong relevance with states of all patients, are extracted, while subspace features, which are in weak relevance with states of all patients but in strong relevance with states of patients under a certain state, are ignored. Eliminated relevant information in subspace features worsens the performance of current classification models. To alleviate the conflict of feature extraction in sparse data, we propose a two-phase classification model with relevant information in both population and subspace features considered. For a patient, his probability under each state is estimated in a space whose dimensions are population features in Phase 1, and in a space whose dimensions are subspace features under that state in Phase 2. The final result of the classification model is based on results in both phases. With both population and subspace features considered and probabilities under each state estimated in a low-dimensional space, the two-phase classification model outperforms other benchmark models both in accuracy and mean absolute error in the hepatic fibrosis diagnosis for patients with chronic hepatitis B. [ABSTRACT FROM AUTHOR]

To efficiently and accurately evaluate the seismic system reliability analysis (SSRA) of cable-stayed bridges subjected to spatially varying ground motions, a direct probabilistic framework was developed in this paper. First, the relevant methods for the structural seismic reliability were presented, including the multiplicative dimensional reduction method, maximum entropy method with fractional moments (FMs), and the product of conditional marginals (PCMs). Second, based on the OpenSees platform, the 3D finite element model of the cable-stayed bridge was established, along with the uncertain structural parameters, stochastic ground motions, and failure modes of each structural component under earthquake loading summarized. Third, considering the double uncertainties of the bridge and ground motions, the nonlinear time history analysis was conducted for the bridge under various scenarios. Finally, the nonlinear seismic response and fractional moment of the structural response were obtained. The maximum entropy method with FMswas used to get the probability density function (pdf) of the structural response, together with the failure probability and reliability index of each component. Considering the correlation between components, the PCMs was used to obtain the failure probability of the bridge under earthquake loadings, and some critical conclusions were drawn. [ABSTRACT FROM AUTHOR]

To study the nonlinear seismic behavior and seismic resistance of the long-span cable-stayed bridges subjected to earthquakes, the multidimensional and multisupported artificial ground motions are synthesized first based on the in situ site conditions of the bridge considering the coherent and traveling wave effects. Then, considering the material nonlinearity of the cable-stayed bridge, a 3D finite element model is established based on the OpenSees platform, and the nonlinear seismic response analysis of the bridge is carried out under the synthetic artificial ground motions. The nonlinear seismic response of main bridge components such as piers, towers, bearings, and cables is analyzed, and key conclusions and observations are drawn. [ABSTRACT FROM AUTHOR]

To investigate the nonlinear impact effect of multispan simply supported beam bridges under strong earthquakes, firstly, the dynamic motion equation, the algorithm of its solution, and some pounding modelling methods are presented and the finite element model of a considered multispan simply supported railway beam bridge is established in the nonlinear finite element software of SAP2000 in which the primary nonlinear characteristics of the bearing and the impact element are considered herein. Secondly, the natural vibration characteristic of the considered railway bridge is analyzed to prepare for the subsequent parameter analysis. Finally, the influence of three nonlinear parameters, i.e., stiffness of impact element, separation gap width of expansion joint, and bearing stiffness, on impact responses of bridge structures is studied. The results show that the first several modes of multispan simply supported beam bridges are mainly longitudinal and vertical vibrations. Under longitudinal seismic excitations, the large longitudinal displacement response is induced possibly and results in the collision or even unseating of superstructures at the expansion joints and abutments. The influence of separation gap width between adjacent decks on the pounding effect of bridges is greater than that of collision stiffness originated from the pounding modelling element. The impact force and pounding number run up to the maximum conditional on the collision stiffness of 9.9 × 109 (N/m) and the separation gap width of 0.14 (m). The bearing stiffness affects significantly the displacement of the pier top and the cross-sectional internal force at the bottom of piers but has little effect on the collision force and number. [ABSTRACT FROM AUTHOR]

Background The effect of corticosteroids on influenza A(H1N1)pdm09 viral pneumonia patients remains controversial, and the impact of dosage has never been studied. Methods Using data of hospitalized adolescent and adult patients with influenza A(H1N1)pdm09 viral pneumonia, prospectively collected from 407 hospitals in mainland China, the effects of low-to-moderate-dose (25-150 mg d−1) and high-dose (>150 mg d−1) corticosteroids on 30-day mortality, 60-day mortality, and nosocomial infection were assessed with multivariate Cox regression and propensity score-matched case-control analysis. Results In total, 2141 patients (median age: 34 years; morality rate: 15.9%) were included. Among them, 1160 (54.2%) had PaO2/FiO2<300 mm Hg on admission, and 1055 (49.3%) received corticosteroids therapy. Corticosteroids, without consideration of dose, did not influence either 30-day or 60-day mortality. Further analysis revealed that, as compared with the no-corticosteroid group, low-to-moderate-dose corticosteroids were related to reduced 30-day mortality (adjusted hazard ratio [ aHR] 0.64 [95% CI 0.43-0.96, P=.033]). In the subgroup analysis among patients with PaO2/FiO2<300 mm Hg, low-to-moderate-dose corticosteroid treatment significantly reduced both 30-day mortality ( aHR 0.49 [95% CI 0.32-0.77]) and 60-day mortality ( aHR 0.51 [95% CI 0.33-0.78]), while high-dose corticosteroid therapy yielded no difference. For patients with PaO2/FiO2 ≥300 mm Hg, corticosteroids (irrespective of dose) showed no benefit and even increased 60-day mortality ( aHR 3.02 [95% CI 1.06-8.58]). Results were similar in the propensity model analysis. Conclusions Low-to-moderate-dose corticosteroids might reduce mortality of influenza A(H1N1)pdm09 viral pneumonia patients with PaO2/FiO2<300 mm Hg. Mild patients with PaO2/FiO2 ≥300 mm Hg could not benefit from corticosteroid therapy. [ABSTRACT FROM AUTHOR]

This paper is concerned with the dynamic responses of a three-span continuous girder bridge with variable cross-section under moving vehicular loads based on the vehicle--bridge coupled vibration analysis. Numerical simulation is used to study the bridge response. Moreover, the effects of different parameters on dynamic load allowance (DLA) and vibration accelerations of the bridge and the vehicle body are discussed. From numerical results, it has been proved that the pavement roughness is the most important factor. In addition, the tested value of DLA cannot be compared with the design value directly. Also, the speed and weight of vehicles limitation is not always an effective way to ensure the safety of the bridge. It may provide some theoretical basis for the design and evaluation of dynamic bridge performance and these are important factors for the maintenance of bridge operations. [ABSTRACT FROM AUTHOR]

This paper is concerned with the inspection and evaluation methods on dynamic performance of highway bridges under moving vehicular loads. The background and development process of the existing specifications are stated and discussed. Up to now, four specifications or drafts for approval related to dynamic performance inspection and evaluation have been published. The deficiencies of the existing specifications are discussed and the differences among them are compared, including dynamic loading test methods, data processing, and evaluation criteria. Finally, some key research topics about the inspection and evaluation methods on dynamic performance of highway bridges are proposed. [ABSTRACT FROM AUTHOR]

This paper proposes an improved high precision direct integration method (I-HPDIM) and an absolute-response-oriented scheme of pseudo-excitation method (PEM) for nonstationary stochastic seismic analysis of large structures under tridirectional nonuniformly modulated spatial ground motions. The proposed approaches resolve the bottle-neck problem of conventional HPDIM and significantly improve computational efficiency of both PEM and HPDIM, making the proposed nonstationary stochastic analysis scheme more attractive for engineering purposes. Hence, it has been implemented in general finite element platforms, having powerful and versatile modelling and analysis capabilities, for stochastic seismic analysis of large and complex structures under tridirectional nonstationary spatial seismic motions. [ABSTRACT FROM AUTHOR]

Background: Fulminant hepatitis is a severe liver disease characterized by massive hepatocyte necrosis and clinical signs of liver failure. This study explores the expression profile of microRNAs, which are regulators of a number of pathophysiological processes, during the early stage of concanavalin A (Con A)-induced hepatitis. Methods: Balb/c mice were given ConA injections to induce fulminant hepatitis. miRNA expression profiling in liver tissues was carried out by microarray analysis. The differentially expressed miRNAs were subjected to time sequence profile analysis, gene-miRNA regulatory network analysis, and gene ontology-miRNA regulatory network analysis. Results: Eleven miRNAs among multiClass were found to be significantly differentially expressed between liver tissue in early stage fulminant hepatitis and normal control liver tissue. Mmu-miR-133a was the most differentially expressed with the strongest regulatory ability, regulating 47 mRNAs. Mmu-miR-10a was the most highly expressed in the microRNA-GO-Network and also exerted a strong regulatory ability. The expression profiles of miR-133a and miR-10a were verified by RT-PCR. Conclusions: These results show that, in the early stage, ConA-induced fulminant hepatitis induces a distinct miRNA expression profile. This differential miRNA expression profile may provide pathogenic clues and potential diagnostic and prognostic markers in acute and severe liver disease. © 2014 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]