372 research outputs found

    Right coronary artery-to-pulmonary artery fistula, the role of echocardiography

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    Coronary artery fistula is an uncommon but hemodynamically significant anomaly of the coronary arteries, occurring as an incidental finding in 0.1% to 0.2% of coronary angiograms. Although half of the patients with a coronary artery fistula remain asymptomatic, the other half develops CHF, infective endocarditis, myocardial ischemia, or rupture of an aneurysm. This report is illustrative of the right coronary artery fistula to the right pulmonary artery in a 57-year-old male. The definitive diagnosis was made during transesophageal echocardiography and confirmed at operation

    Effect of shape and size of sampling window on the determination of average length, intensity and density of trace discontinuity

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    The fractures geometrical characteristics can be calculated by various sampling methods in 1 dimension (1D) & 2 dimensions (2D). The Discrete Fracture Network (DFN) simulation results show some of the equations are suitable for calculation of mean trace length and the difference between actual value and their values is less than 15%. Apparent density is dependent on scale, but the Mauldon's estimators are independent of scale despite the variation in fracture length. For all joint sets, the difference of apparent areal intensity by samplings windows and circular estimator is less than 5% proportionate to actual value. A reduction of Fisher constant doesn't have much effect on mean trace length of the fractures with length less than 1.5 m, but it results in a 21% difference for fractures with length longer than 1.5 m. Variation of this parameter affects the density, too and the difference can be 5% to 10% depending on fracture length. But, variation in Fisher constant doesn't have any effect on areal intensity for fractures with length less than 2 m

    MeshfreeFlowNet: A Physics-Constrained Deep Continuous Space-Time Super-Resolution Framework

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    We propose MeshfreeFlowNet, a novel deep learning-based super-resolution framework to generate continuous (grid-free) spatio-temporal solutions from the low-resolution inputs. While being computationally efficient, MeshfreeFlowNet accurately recovers the fine-scale quantities of interest. MeshfreeFlowNet allows for: (i) the output to be sampled at all spatio-temporal resolutions, (ii) a set of Partial Differential Equation (PDE) constraints to be imposed, and (iii) training on fixed-size inputs on arbitrarily sized spatio-temporal domains owing to its fully convolutional encoder. We empirically study the performance of MeshfreeFlowNet on the task of super-resolution of turbulent flows in the Rayleigh-Benard convection problem. Across a diverse set of evaluation metrics, we show that MeshfreeFlowNet significantly outperforms existing baselines. Furthermore, we provide a large scale implementation of MeshfreeFlowNet and show that it efficiently scales across large clusters, achieving 96.80% scaling efficiency on up to 128 GPUs and a training time of less than 4 minutes.Comment: Supplementary Video: https://youtu.be/mjqwPch9gDo. Accepted to SC2

    Occurrence and molecular characterization of a 16SrI-R subgroup phytoplasma associated with Aquilegia vulgaris phyllody disease

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    During 2016–2017 surveys, carried out for phytoplasma diseases in ornamental plants in Chaharmahal and Bakhtiari provinces, Iran, found symptoms of virescence, phyllody, reduced size of leaves and flowers in columbine (Aquilegia vulgaris). Total DNAs extracted from symptomatic and symptomless plants were tested for the presence of phytoplasma using P1/P7 and R16F2n/R16R2 primers in direct and nested PCR producing amplicons of about 1.8 and 1.2 kb, respectively, from all symptomatic A. vulgaris plants, but not from symptomless ones. The consensus sequence of the detected phytoplasma named Aquilegia phyllody (APh) was 100% identical with strains clustering to phytoplasmas enclosed in the 16SrI group as also confirmed by phylogenetic analyses. Both real and virtual restriction fragment length polymorphism analysis of R16F2n/R16R2 amplicons showed profiles that were identical to each other and indicated the affiliation of the APh phytoplasma to the 16SrI-R subgroup. This is the first report of a 16SrI-R phytoplasma associated with this A. vulgaris phyllody disease

    Prevalence and new histopathological aspects of Haemoproteus spp. in pigeons from Iran

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    ΔΕΝ ΔΙΑΤΙΘΕΤΑΙ ΠΕΡΙΛΗΨΗHaemoproteus spp. is pathogenic protozoan that effecting blood circulatory system of birds. The present study was undertaken to evaluate the presence of Haemoproteus spp. in pigeons from Iran and associatedhistopathological changes. A total of 108 blood samples were taken from pigeons to investigate Haemoproteus spp. presence by blood smear and semi-nested PCR targeting the cytochrome b gene methods. Also, to evaluate histopathological changes 12 infected pigeons to Haemoproteus were sacrificed and studied. 34.2% of pigeons infected with Haemoproteus showed macro and microgametocytes in their erythrocytes while based on the molecular method 63.8% were infected. Focal lymphocytic aggregates, pigmentation and cell swelling were the main histopathological lesions in infected livers. Multifocal non- suppurative interstitial nephritis, pigmentation and splenic lymphoid hyperplasia were also seen in the infected pigeons. Mild lymphocytic myocarditis in the heart of one pigeon was the other finding. No histopathological changes were seen in brain, intestine, and pancreas. Schizonts with variable shapes and sizes were detected in infected livers, lungs, kidneys, and spleens but megaloschizonts were not found. This study also reports the molecular prevalence of Haemoproteus spp. in Ira

    Recurrent intracardiac leiomyomatosis

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    An intravenous leiomyoma, a histologically benign smooth muscle tumour, arises from either a uterine myoma or the walls of a uterine vessel, with extension into veins. The present report describes echocardiographic features of an intravenous leiomyoma that spread into the right-sided cardiac chambers in a middle-aged woman who bad undergone a hysterectomy two years earlier. Echocardiographic features included an elongated mobile mass extending from the inferior vena cava and multiple masses in the right atrium and right ventricle. Intracardiac leiomyomatosis should be considered in women who present with a cardiac mass in the right-sided chambers. © 2007 Pulsus Group Inc. All rights reserved

    Experimental Investigation of Flow and Coherent Properties of Excited Non-Circular Liquid Jets

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    Non-circular jet is identified as an efficient passive flow-control technique that attracts many research topics. The existence of twine-vortexes is the main reason for dissimilarity between circular and non-circular jets. Which also influences the production of droplets and satellites as well as the jet instability. This investigation presents instability analysis of liquid-gas interface as an applicable conception in free-jet flows. We experiment different jet geometries within a gas ambient in order to study their hydrodynamic behavior. These studies give an appropriate perception about contributing forces that play essential roles in fluid instability. We focus on varying viscosity and surface tension as our excitation techniques. These methods are vital to examine the key properties of non-circular jets such as breakup and decay length, axis-switching wavelength as well as produced droplets and satellites characteristics. First, instabilities of charged liquid jets are investigated by considering the interaction between electric and inertial forces. Also, the viscosity effect was studied for its interaction with the inertial and surface tension forces. In each case, liquid jet in-stability for various nozzle geometries over a specific range of jet velocity is examined. The obtained results illustrate that the geometry of nozzle has an important effect on jet instability. In addition, by increment of We number, the breakup and decay length as well as the axis-switching wavelength are raising. However, by the rise of twin-vortex number, the breakup length increases but the decay length and axis-switching wavelength decrease

    Measurement of pulmonary arterial elastance in patients with systolic heart failure using Doppler echocardiography

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    Objective: A reliable and easy-to-perform method for measuring right ventricular (RV) afterload is desirable when scheduling patients with systolic heart failure to undergo heart transplantation. The present study aimed to investigate the accuracy of echocardiographically-derived pulmonary arterial elastance as a measurement of pulmonary vascular resistance by comparing it with invasive measures. Methods: Thirty-one patients with moderate to severe systolic heart failure, including 22 (71) male patients, with a mean age of 41.16±15.9 years were enrolled in the study. Right heart catheterization and comprehensive echocardiography during the first hour after completion of cardiac catheterization were performed in all the patients. The pulmonary artery elastance was estimated using the ratio of end-systolic pressure (Pes) over the stroke volume (SV) by both cardiac catheterization Ea (PV)-C and echocardiography Ea (PV)-E. Results: The mean Ea (PV)-C and Ea (PV)-E were estimated to be 0.73±0.49 mm Hg/mL and 0.67±0.44 mm Hg/mL, respectively. There was a significant relation between Ea (PV)-E and Ea (PV)-C (r=0.897, p<0.001). Agreement between echocardiography and catheterization methods for estimating Ea (PV), investigated by the Bland-Altman method, showed a mean bias of -0.06, with 95% limits of agreement from -0.36 mm Hg/mL to 0.48 mm Hg/mL. Conclusion: Doppler echocardiography is an easy, non-invasive, and inexpensive method for measuring pulmonary arterial elastance, which provides accurate and reliable estimation of RV afterload in patients with systolic heart failure. © 2016 by Turkish Society of Cardiology
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