Hemodynamic prediction in patent ductus arteriosus morphologies

Patent ductus arteriosus (PDA) is a condition in which the ductus arteriosus remain opened after birth, causing the blood to shunt through from the aorta to the pulmonary artery. However, due to the complicated nature of the arterial geometry, the flow characteristic inside the PDA is not fully understood, since simplified model are commonly used in researches. This study aims to identify the hemodynamic characteristic in three different patient-specific morphologies. Computational modeling via computational fluid dynamic (CFD) is implemented to predict the blood flow behavior in different PDA morphologies. The result shows that low wall shear stress is observed at the region where the flow recirculation occurs. High wall shear stress is observed in the pulmonary artery due to increase of flow velocity at the insertion point of PDA. The PDA morphologies exhibit left-to-right shunt, which diverts approximately 10% of blood flow from the aorta to the pulmonary artery. The highest shunted blood flow is found in TR LPA morphology. High value of OSI indicates the changes of wall shear stress vector. It is observed that DS LPA has the highest area covered by OSI which presents better hemodynamic characteristic as compared to other morphology

Storyline description of Southern Hemisphere midlatitude circulation and precipitation response to greenhouse gas forcing

As evidence of climate change strengthens, knowledge of its regional implications becomes an urgent need for decision making. Current understanding of regional precipitation changes is substantially limited by our understanding of the atmospheric circulation response to climate change, which to a high degree remains uncertain. This uncertainty is reflected in the wide spread in atmospheric circulation changes projected in multimodel ensembles, which cannot be directly interpreted in a probabilistic sense. The uncertainty can instead be represented by studying a discrete set of physically plausible storylines of atmospheric circulation changes. By mining CMIP5 model output, here we take this broader perspective and develop storylines for Southern Hemisphere (SH) midlatitude circulation changes, conditioned on the degree of global-mean warming, based on the climate responses of two remote drivers: the enhanced warming of the tropical upper troposphere and the strengthening of the stratospheric polar vortex. For the three continental domains in the SH, we analyse the precipitation changes under each storyline. To allow comparison with previous studies, we also link both circulation and precipitation changes with those of the Southern Annular Mode. Our results show that the response to tropical warming leads to a strengthening of the midlatitude westerly winds, whilst the response to a delayed breakdown (for DJF) or strengthening (for JJA) of the stratospheric vortex leads to a poleward shift of the westerly winds and the storm tracks. However, the circulation response is not zonally symmetric and the regional precipitation storylines for South America, South Africa, South Australia and New Zealand exhibit quite specific dependencies on the two remote drivers, which are not well represented by changes in the Southern Annular Mode

Numerical simulation of concentration over-voltage in a polymer electrolyte fuel cell under low-hydrogen conditions

This article elucidates the effect of low hydrogen concentration fuel gas on polymer electrolyte fuel cell (PEFC) performance, with particular emphasis on the transport of chemical species in the anode separator channel and the electrochemical reactions. A numerical simulation model for PEFCs was developed; the model combined a computational fluid dynamics model for mass transfer in the anode separator and the gas diffusion layer(GDL)as well as a PEFC electrochemical reaction model takinginto account the activation, concentration, and resistance over-voltages. The emphasis in this study is placed on obtaining a basic understanding of how three-dimensional flow and low-hydrogen fuel transport phenomena in the anode separator channelimpactthe electrochemical processes occurring in PEFCs. Comparison of the numerical simulation results with experimental data indicates that the performance degradation in PEFCs is negligible for hydrogen concentrations over 30%, whereas it becomes significant for concentrations below 10%. Furthermore, the numerical simulationresults showthat controlling the fuel supply flow rate stimulates hydrogen transport inthe GDL and the catalyst layer, which consequently enhances PEFC performance under low-hydrogen conditions

Flow Analysis on Fusiform Aneurysm during Exercise Condition

The dilation of fusiform aneurysm can yield unexpected predicament. The aneurysm is prone to rupture if not immediately treated. This study is focuses on investigate the flow behaviour inside the fusiform aneurysm during exercise condition under normal blood pressure (NBP) and high blood pressure (HBP). The results of this study shows the presence of the flow recirculation is observed at aneurysm region during exercise condition. The presence of the flow recirculation is proportional to the increase of flow activity at the aneurysm. The flow activity is much higher at distal end compared to proximal end region. The different of flow activity shows the different strength of the flow recirculation occurred at the aneurysm bulge. The results also show HBPE peak systole distribute the highest value of the pressure among others condition which is exhibits the high risk of the aneurysm from rupture

Detrusor Underactivity and Underactive Bladder in Women : What Is New?

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Compact patch MIMO antenna with low mutual coupling for WLAN applications

A compact triband microstrip patch MIMO antenna is proposed for WLAN applications. The antenna consists of two patches antenna elements, which are orthogonally placed to each other for high isolation at 2.4, 2.8 and 5.8 GHz frequency bands. On its ground plane, a Complementary Split Ring Resonators (CSRRs) is etched for size reduction and multiband generation. The proposed compact MIMO antenna covers an entire size of 58 x 45 x 1.6 mm3, with the patch size of 13.3 x 17.1 mm2. A 79% size reduction at 2.45 GHz was achieved for miniaturization, with a very low mutual coupling (S21 and S12) of -32 dB at all bands

Cardiac tamponade from a giant thymoma: case report

Thymoma, the most common neoplasm of the anterior mediastinum especially in adults, accounts for 20-25% of all mediastinal tumors and 50% of anterior mediastinal masses. These tumors are routinely asymptomatic for prolonged periods of time. Pericardial tamponade is a very rare initial manifestation of a thymoma. This report presents a patient who had hemorrhagic pericardial tamponade that likely resulted from the largest symptomatic mixed type (type AB) thymoma described in the literature

The conceptual and practical ethical dilemmas of using health discussion board posts as research data.

Increasing numbers of people living with a long-term health condition are putting personal health information online, including on discussion boards. Many discussion boards contain material of potential use to researchers; however, it is unclear how this information can and should be used by researchers. To date there has been no evaluation of the views of those individuals sharing health information online regarding the use of their shared information for research purposes

How should we measure psychological resilience in sport performers?

Psychological resilience is important in sport because athletes must constantly withstand a wide range of pressures to attain and sustain high performance. To advance psychologists’ understanding of this area, there exists an urgent need to develop a sport-specific measure of resilience. The purpose of this paper is to review psychometric issues in resilience research and to discuss the implications for sport psychology. Drawing on the wider general psychology literature to inform the discussion, the narrative is divided into three main sections relating to resilience and its assessment: adversity, positive adaptation, and protective factors. The first section reviews the different ways that adversity has been measured and considers the potential problems of using items with varying degrees of controllability and risk. The second section discusses the different approaches to assessing positive adaptation and examines the issue of circularity pervasive in resilience research. The final section explores the various issues related to the assessment of protective factors drawing directly from current measures of resilience in other psychology sub-disciplines. The commentary concludes with key recommendations for sport psychology researchers seeking to develop a measure of psychological resilience in athletes