GPU Accelerated Time-Domain Discrete Geometric Approach Method for Maxwell's Equations on Tetrahedral Grids

A recently introduced time-domain method for the numerical solution of Maxwell's equations on unstructured grids is reformulated in a novel way, with the aim of implementation on graphical processing units (GPUs). Numerical tests show that the GPU implementation of the resulting scheme yields correct results, while also offering an order of magnitude in speedup and still preserving all of the main properties of the original finite-difference time-domain algorithm. © 2017 IEEE

A face-smoothed cell method for static and dynamic piezoelectric coupled problems on polyhedral meshes

Low-order discretization schemes are suitable for modeling 3-D multiphysics problems since a huge number of degrees of freedom (DoFs) is typically required by standard high-order Finite Element Method (FEM). On the other hand, polyhedral meshes ensure a great flexibility in the domain discretization and are thus suitable for complex model geometries. These features are useful for the multiphysics simulation of micro piezoelectric devices with a thin multi-layered and multi-material structure. The Cell Method (CM) is a low-order discretization scheme which has been mainly adopted up to now for electromagnetic problems but has not yet been used for mechanical problems with polyhedral discretization. This work extends the CM to piezo-elasticity by reformulating local constitutive relationships in terms of displacement gradient. In such a way, piecewise uniform edge basis functions defined on arbitrary polyhedral meshes can be used for discretizing local constitutive relationships. With the CM matrix assembly is completely Jacobian-free and do not require Gaussian integration, reducing code complexity. The smoothing technique, firstly introduced for FEM, is here extended to CM in order to avoid shear locking arising when low-order discretization is used for thin cantilevered beams under bending. The smoothed CM is validated for static and dynamic problems on a real test case by comparison with both second-order FEM and experimental data. Numerical results show that accuracy is retained even if a much lower number of DoFs is required compared to FEM

Pregnancy in patients with tuberculosis: A TBNET cross-sectional survey

BACKGROUND: Objectives: To determine whether the incidence of tuberculosis with pregnancy is more common than would be expected from the crude birth rate; to see whether there is significant delay in the diagnosis of tuberculosis during pregnancy. METHOD: Design: A cross-sectional survey. SETTING: 13 tuberculosis clinics within different European countries and the USA. POPULATION/SAMPLE: All patients with tuberculosis seen at these clinics for a period\u2009>\u20091 year. INSTRUMENT: Questionnaire survey based on continuous data collection. MAIN OUTCOME MEASURES: number and proportion of women with tuberculosis who were pregnant; timing of diagnosis in relation to pregnancy, including those who were pregnant or delivered in the 3 months prior to the diagnosis of TB and those who developed TB within 3 months after delivery. RESULTS: Pregnancy occurred in 224 (1.5 %) of 15,217 TB patients and followed the expected rate predicted from the crude birth rate for the clinic populations. TB was diagnosed more commonly in the 3 months after delivery (n\u2009=\u2009103) than during pregnancy (n\u2009=\u200968; \u3c7 2\u2009=\u200925.1, P\u2009<\u20090.001). CONCLUSIONS: TB is diagnosed more frequently after delivery, despite variations in local TB incidence and healthcare systems

The Italian registry of pulmonary non-tuberculous mycobacteria - IRENE:The study protocol

Background: A substantial increase in pulmonary and extra-pulmonary diseases due to non-tuberculous mycobacteria (NTM) has been documented worldwide, especially among subjects suffering from chronic respiratory diseases and immunocompromised patients. Many questions remain regarding the epidemiology of pulmonary disease due to NTM (NTM-PD) mainly because reporting of NTM-PD to health authorities is not mandated in several countries, including Italy. This manuscript describes the protocol of the first Italian registry of adult patients with respiratory infections caused by NTM (IRENE). Methods: IRENE is an observational, multicenter, prospective, cohort study enrolling consecutive adult patients with either a NTM respiratory isolate or those with NTM-PD. A total of 41 centers, including mainly pulmonary and infectious disease departments, joined the registry so far. Adult patients with all of the following are included in the registry: 1) at least one positive culture for any NTM species from any respiratory sample; 2) at least one positive culture for NTM isolated in the year prior the enrolment and/or prescribed NTM treatment in the year prior the enrolment; 3) given consent to inclusion in the study. No exclusion criteria are applied to the study. Patients are managed according to standard operating procedures implemented in each IRENE clinical center. An online case report form has been developed to collect patients' demographics, comorbidities, microbiological, laboratory, functional, radiological, clinical, treatment and outcome data at baseline and on an annual basis. An IRENE biobank has also been developed within the network and linked to the clinical data of the registry. Conclusions: IRENE has been developed to inform the clinical and scientific community on the current management of adult patients with NTM respiratory infections in Italy and acts as a national network to increase the disease's awareness