190 research outputs found

    ON POTENTIALIZED PARTIAL FINITE DIFFERENCE EQUATIONS: ANALYZING THE COMPLEXITY OF KNOWLEDGE-BASED SPATIAL ECONOMIC DEVELOPMENTS

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    Knowledge-based regional and urban studies are plentiful; some systematics might be in order at this junction, so first the different links between economic production units in geographical space have to be clearly defined. Then a tool to represent the dynamics of those links should be selected; potentialized partial differential equations (PPDEs) are an appropriate tool to represent space-time relations in pre-geographical space. In practice, however, only discrete data are available, hence the question of how finite differences could generate PPFDEs (potentialized partial finite difference equations). A case has been worked out and simulated, showing a high degree of spatio-temporal complexity. Spatial econometric estimation is possible, as other work has shown; so an application to empirical data for France could be presented. Different versions of the latter have been worked out; they are presented in succession, followed by a last exercise on US data.COMPLEXITY, SPATIAL ECONOMETRICS, POTENTIAL, FINITE DIFFERENCES

    Percutaneous closure of PFO in patients with reduced oxygen saturation at rest and during exercise : short- and long-term results

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    Background. A patent foramen ovale (PFO) is a rare cause of hypoxemia and clinical symptoms of dyspnea. Due to a right-to-left shunt, desaturated blood enters the systemic circulation in a subset of patients resulting in dyspnea and a subsequent reduction in quality of life (QoL). Percutaneous closure of PFO is the treatment of choice. Objectives. This retrospective multicentre study evaluates short- and long-term results of percutaneous closure of PFO in patients with dyspnea and/or reduced oxygen saturation. Methods. Patients with respiratory symptoms were selected from databases containing all patients percutaneously closed between January 2000 and September 2018. Improvement in dyspnea, oxygenation, and QoL was investigated using pre- and postprocedural lung function parameters and two postprocedural questionnaires (SF-36 and PFSDQ-M). Results. The average follow-up period was 36 [12-43] months, ranging from 0 months to 14 years. Percutaneous closure was successful in 15 of the 16 patients. All patients reported subjective improvement in dyspnea immediately after device deployment, consistent with their improvement in oxygen saturation (from 90 +/- 6% to 94 [92-97%] on room air and in upright position) (p<0.05). Both questionnaires also indicated an improvement of dyspnea and QoL after closure. The two early and two late deaths were unrelated to the procedure. Conclusion. PFO-related dyspnea and/or hypoxemia can be treated successfully with a percutaneous intervention with long-lasting benefits on oxygen saturation, dyspnea, and QoL

    De-differentiated myxofibrosarcoma metastasis in the right atrium

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    Solitary cardiac metastasis remains an uncommon diagnosis. Herein, the authors report describes a rare case of a 53-year-old woman with cardiac metastasis of a peripheral de-differentiated myxofibrosarcoma. This case demonstrates the complexity of pairing multimodality imaging and invasive techniques to achieve tissue characterization and diagnosis. (Level of Difficulty: Beginner.

    Late gadolinium enhancement CMR in primary mitral regurgitation.

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    AIMS: The appropriate timing for surgery in severe asymptomatic primary mitral regurgitation (MR) remains controversial. It has been shown that late gadolinium enhancement on cardiovascular magnetic resonance (LGE CMR), which may identify myocardial fibrosis, is associated with a worse outcome in various cardiomyopathies. We sought to investigate the prevalence and significance of delayed enhancement in primary MR. METHODS: We prospectively included 41 patients with at least moderate primary MR and without overt signs of left ventricular (LV) dysfunction. Patients with evidence of coronary artery disease, arrhythmias or significant concomitant valvular disease were excluded. All patients were scheduled for transthoracic echocardiography and LGE CMR. RESULTS: A total of 39 patients had interpretable LGE CMR images. Among them, 12 (31%) had late contrast uptake of the LV wall. LGE CMR showed an infarct pattern in three patients, a pattern of mid-wall fibrosis in seven patients and two patients had a combined pattern. Patients with delayed enhancement on CMR had significant higher LV diameters (LV end-systolic diameter 39 +/- 4 vs. 34 +/- 5 mm, P = 0.002; LV end-diastolic diameter 57 +/- 5 vs. 50 +/- 5 mm, P = 0.001). There was a trend towards a higher indexed left atrial volume (55 +/- 21 vs. 44 +/- 13 mL/m(2), P = 0.06). By contrast, there was no significant association between myocardial contrast uptake and age, LV ejection fraction and MR severity. CONCLUSION: Left ventricular remodelling seems to be associated with the presence of delayed enhancement on CMR in primary MR. Further data are needed to determine whether LGE CMR can predict a less favourable outcome or could improve risk stratification in asymptomatic primary MR

    Circulating CD34 + /KDR + endothelial progenitor cells are reduced in chronic heart failure patients as a function of Type D personality

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    A B S T R A C T The aim of the present study was to assess whether EPC (endothelial progenitor cell) number/function might be an explanatory factor for the observed relationship between Type D personality (a joint tendency towards negative affectivity and social inhibition) and poor cardiovascular prognosis. We also assessed whether the effect of a single exercise bout on EPC number/function was affected by Type D personality. A total of 35 sedentary men with CHF (chronic heart failure; left ventricular ejection fraction 45 %) underwent CPET (cardiopulmonary exercise testing) and personality assessment with the 14-item Type D scale. CD34 + /KDR (kinase insert domain-containing receptor) + cells were quantified by flow cytometry before and immediately after CPET. Migration of early EPC towards VEGF (vascular endothelial growth factor) and SDF-1α (stromal-cell-derived factor-1α) was investigated. Type D (n = 10) and non-Type D (n = 25) patients were comparable with regards to demographics, disease severity and Framingham risk factor score. Circulating EPC numbers were reduced by 54 % in Type D compared with non-Type D patients (0.084 + − 0.055 and 0.183 + − 0.029 % of lymphocytes respectively; P = 0.006). Exercise led to a 60 % increase in EPC in Type D patients, whereas the EPC number remained unchanged in the non-Type D group (P = 0.049). Baseline migratory capacity was related to disease severity, but was not different between Type D and non-Type D patients. Exercise induced a highly significant enhancement of migratory capacity in both groups. In conclusion, reduced EPC numbers might explain the impaired cardiovascular outcome in Type D patients. The larger increase in circulating EPCs observed in these patients suggests that acute exercise elicits a more pronounced stimulus for endothelial repair

    Clinical and Hemodynamic Effects of Percutaneous Edge-to-Edge Mitral Valve Repair in Atrial Versus Ventricular Functional Mitral Regurgitation.

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    The present study aims to assess the clinical and hemodynamic impact of percutaneous edge-to-edge mitral valve repair with MitraClip in patients with atrial functional mitral regurgitation (A-FMR) compared with ventricular functional mitral regurgitation (V-FMR). Mitral regurgitation (MR) grade, functional status (New York Heart Association class), and major adverse cardiac events (MACE; all-cause mortality or hospitalization for heart failure) were evaluated in 52 patients with A-FMR and in 307 patients with V-FMR. In 56 patients, hemodynamic assessment during exercise echocardiography was performed before and 6 months after intervention. MR reduction after MitraClip implantation was noninferior in A-FMR compared with V-FMR (MR grade ≤2 at 6 months in 94% vs 82%, respectively, p <0.001 for noninferiority) and was associated with improvement of functional status (New York Heart Association class ≤2 at 6 months in 90% vs 80%, respectively, p = 0.2). Hemodynamic assessment revealed that cardiac output at 6 months was higher in A-FMR at rest (5.1 ± 1.5 L/min vs 3.8 ± 1.5 L/min, p = 0.002) and during peak exercise (7.9 ± 2.4 L/min vs 6.1 ± 2.1 L/min, p = 0.02). In addition, the reduction in systolic pulmonary artery pressure at rest was more pronounced in A-FMR: Δ SPAP -13.1 ± 15.1 mm Hg versus -2.2 ± 13.3 mm Hg (p = 0.03). MACE rate at follow-up was significantly lower in A-FMR versus V-FMR, with an adjusted odds ratio of 0.46 (95% confidence interval 0.24 to 0.88), which was caused by a reduction in hospitalization for heart failure. In conclusion, percutaneous edge-to-edge mitral valve repair with MitraClip is at least as effective in A-FMR as in V-FMR in reducing MR. However, the hemodynamic improvement and reduction of MACE were significantly better in A-FMR

    The continental divide? Economic exposure to Brexit in regions and countries on both sides of The Channel

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    In this paper we employ an extension of the World Input‐OutputDatabase (WIOD) with regional detail for EU countries to study thedegree to which EU regions and countries are exposed to negativetrade‐related consequences of Brexit. We develop an index of thisexposure, which incorporates all effects due to geographicallyfragmented production processes within the UK, the EU andbeyond. Our findings demonstrate that UK regions are far moreexposed than regions in other countries. Only regions in theRepublic of Ireland face exposure levels similar to some UK regions,while the next most affected regions are in Germany, TheNetherlands, Belgium and France. This imbalance may influencethe outcomes of the negotiations between the UK and the EU
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