Pericardial effusion unrelated to surgery is a predictor of mortality in heart transplant patients

Background: Hemodynamically irrelevant pericardial effusion (PeEf) is a predictor of adverse outcome in heart failure patients. The clinical relevance of a PeEf unrelated to surgery in heart transplant patients remains unknown. This study assesses the prognostic value of PeEf occurring later than 1 year after transplantation. Methods: All patients undergoing heart transplantation in Zurich between 1989 and 2012 were screened. Cox proportional hazard models were used to analyze mortality (primary) and hospitalization (secondary endpoint). PeEf time points were compared to baseline for rejection, immunosuppressants, tumors, inflam­mation, heart failure, kidney function, hemodynamic, and echocardiographic parameters. Results: Of 152 patients (mean age 48.3 ± 11.9), 25 developed PeEf. Median follow-up period was 11.9 (IQR 5.8–17) years. The number of deaths was 6 in the PeEf group and 46 in the non-PeEf group. The occurrence of PeEf was associated with a 2.5-fold increased risk of death (HR 2.49, 95% CI 1.02–6.13, p = 0.046) and hospitalization (HR 2.53, 95% CI 1.57–4.1, p = 0.0002). Conclusions: This study reveals that the finding of hemodynamically irrelevant PeEf in heart trans­plant patients is a predictor of adverse outcome, suggesting that a careful clinical assessment is war­ranted in heart transplant patients exhibiting small PeEf

A comparative study of turbulence models in a transient channel flow

Open Access funded by Engineering and Physical Sciences Research Council Under a Creative Commons license The authors would like to acknowledge the financial support provided by the Engineering and Physical Sciences Research Council (EPSRC) through the Grant No. EP/G068925/1.Peer reviewedPublisher PD

A new combination: obesity surgery and acupuncture versus the disease of this century - obesity

Obesity is the most common health problem of this century. The causes of overweight and obesity are complex. Over 1 million people on earth are currently obese. More importantly, 10% of them are children. Obstructive sleep apnea syndrome (OSAS), certain corporal changes like arthritis, or psychological effects stemming from the change of the outlook of the body are some of the problems.Studies are continuously conducted, focusing on the way obesity affects the quality of life.Obesity surgery is the most frequently used approach. The literature sources we have examined indicated very high success rates. However, the most important problem concerns postoperative complications. Another way to treat obesity is acupuncture, which is linked to a lower incidence of complications. It is cheaper and an easier ap­proach to apply. Of course, there are a lot of studies about acupuncture effectiveness in obesity treatment. But it is not enough when used on its own. In our opinion, acupuncture could be combined with obesity surgery when treating obesity. This could reduce the complications from both the preoperative and postoperative period. It could be successful in creating new life standards and, of course, it may improve the outcome of the surgery

Quantitative analysis of flow visualizations in an unsteady channel flow

International audienc

Fine Structure of Reynolds Shear Stress in an Unsteady Turbulent Channel Flow

International audienc

Large-eddy simulation of accelerated turbulent flow in a circular pipe

Turbulent pipe flows subject to temporal acceleration have been considered in this study. Large-eddy simulations (LESs) of accelerated turbulent flow in a circular pipe were performed to study the response of the turbulent flow to temporal acceleration. The simulations were started with the fully-developed turbulent pipe flow at an initial Re number, and then a constant temporal acceleration was applied. During the acceleration, the Reynolds number of the pipe flow, based on the pipe diameter and the bulk-mean velocity, increased linearly from ReD = 7000 to 36,000. A dimensionless response time for various flow quantities was introduced to measure the delays in the response of the near-wall turbulence to temporal acceleration. The results reveal distinctive features of the delays responsible for turbulence production, energy redistribution, and radial propagation. The conditionally-averaged flow fields associated with Reynolds shear stress producing events were analysed. In the transient flows, sweeps and ejections were closely linked to the delays of turbulence production and of turbulence propagation away from the wall. It is found that strong sweep events were related to the delayed turbulence production in the near-wall region, while ejection events were associated with the propagation of the turbulence away from the wall. The results show that the anisotropy of the turbulence was enhanced during the transient, and this would be a challenging problem to standard turbulence models