Kinetic energy transfers between mesoscale and submesoscale motions in the open ocean’s upper layers

Mesoscale eddies contain the bulk of the ocean’s kinetic energy (KE), but fundamental questions remain on the cross-scale KE transfers linking eddy generation and dissipation. The role of submesoscale flows represents the key point of discussion, with contrasting views of submesoscales as either a source or a sink of mesoscale KE. Here, the first observational assessment of the annual cycle of the KE transfer between mesoscale and submesoscale motions is performed in the upper layers of a typical open-ocean region. Although these diagnostics have marginal statistical significance and should be regarded cautiously, they are physically plausible and can provide a valuable benchmark for model evaluation. The cross-scale KE transfer exhibits two distinct stages, whereby submesoscales energize mesoscales in winter and drain mesoscales in spring. Despite this seasonal reversal, an inverse KE cascade operates throughout the year across much of the mesoscale range. Our results are not incompatible with recent modeling investigations that place the headwaters of the inverse KE cascade at the submesoscale, and that rationalize the seasonality of mesoscale KE as an inverse cascade-mediated response to the generation of submesoscales in winter. However, our findings may challenge those investigations by suggesting that, in spring, a downscale KE transfer could dampen the inverse KE cascade. An exploratory appraisal of the dynamics governing mesoscale-submesoscale KE exchanges suggests that the upscale KE transfer in winter is underpinned by mixed-layer baroclinic instabilities, and that the downscale KE transfer in spring is associated with frontogenesis. Current submesoscale-permitting ocean models may substantially understate this downscale KE transfer, due to the models’ muted representation of frontogenesis.

How to decide which COVID-19 patient with myocardial infarction to send to the Cath Lab? - A case series of COVID-19 patients with myocardial infarction (Preprint)

BACKGROUND The Coronavirus pandemic has hit the world with its vast contagiousness, high morbidity, and mortality. Apart from the direct damage to the lung tissue, the corona virus infection is able to predispose patients to thrombotic disease, thus causing cerebral or coronary incidents. OBJECTIVE The aim of this study was to find a clinical or laboratory parameter, that would help in distinguishing between COVID-19 patients with myocardial infarction (MI), who have an infarct-related artery (IRA) and therefore, require immediate revascularization, and those, who have no IRA. METHODS This was a single-center, observational study of 10 consecutive patients with COVID-19, who were admitted with confirmed MI. RESULTS In our study group the mean age was 67.5 ± 8.3 years, half of the patients were female; all of them had arterial hypertension; 8 patients (80%) had dyslipidemy; 4 (40%) had diabetes. 30% of the patients with MI did not have an IRA, and did not require pPCI. Patients with MI and IRA had significantly higher hsTrI values (48.9 ± 43.2 vs 0.6 ± 0.7, p=0.007) and exclusively typical chest pain 100% vs 0%, p=0.007), compared to patients with MI without an IRA. The ECG changes had only marginal statistical significance. Our results suggest that using a higher cut-off value for hsTrI (>7.5 times upper reference range) increases the specificity and positive predictive value for diagnosing a MI with the presence of IRA and need for pPCI, to 100% CONCLUSIONS In our analysis we confirm that a higher cut-off value for hsTrI helps distinguish between COVID patients with MI, who have IRA and therefore, require immediate revascularization, compared to those, who have no IRA.

How to decide which COVID-19 patient with myocardial infarction to send to the Cath Lab? - A case series of COVID-19 patients with myocardial infarction

INTRODUCTIONThe Coronavirus pandemic has hit the world with its vast contagiousness, high morbidity, and mortality. Apart from the direct damage to the lung tissue, the corona virus infection is able to predispose patients to thrombotic disease, thus causing cerebral or coronary incidents.AIMSThe aim of this study was to find a clinical or laboratory parameter, that would help in distinguishing between COVID-19 patients with myocardial infarction (MI), who have an infarct-related artery (IRA) and therefore, require immediate revascularization, and those, who have no IRA.METHODSThis was a single-center, observational study of 10 consecutive patients with COVID-19, who were admitted with confirmed MI.RESULTSIn our study group the mean age was 67.5 ± 8.3 years, half of the patients were female; all of them had arterial hypertension; 8 patients (80%) had dyslipidemy; 4 (40%) had diabetes. 30% of the patients with MI did not have an IRA, and did not require pPCI. Patients with MI and IRA had significantly higher hsTrI values (48.9 ± 43.2 vs 0.6 ± 0.7, p=0.007) and exclusively typical chest pain 100% vs 0%, p=0.007), compared to patients with MI without an IRA. The ECG changes had only marginal statistical significance. Our results suggest that using a higher cut-off value for hsTrI (>7.5 times upper reference range) increases the specificity and positive predictive value for diagnosing a MI with the presence of IRA and need for pPCI, to 100%CONCLUSIONIn our analysis we confirm that a higher cut-off value for hsTrI helps distinguish between COVID patients with MI, who have IRA and therefore, require immediate revascularization, compared to those, who have no IRA.

Parathyroidectomy Is Associated with Reduced Mortality in Hemodialysis Patients with Secondary Hyperparathyroidism

Secondary hyperparathyroidism increases morbidity and mortality in hemodialysis patients. The Kidney Disease Outcomes Quality Initiative Guidelines recommend parathyroidectomy for patients with chronic kidney disease and parathyroid hormone concentrations exceeding 800 pg/mL; however, this concentration represents an arbitrary cut-off value. The present study was conducted to identify factors influencing mortality in hemodialysis patients with parathyroid hormone concentrations exceeding 800 pg/mL and to evaluate the effects of parathyroidectomy on outcome for these patients. Two hundred twenty-one hemodialysis patients with parathyroid hormone concentrations > 800 pg/mL from July 2004 to June 2010 were identified. 21.1% of patients (n = 60) received parathyroidectomy and 14.9% of patients (n = 33) died during a mean follow-up of 36 months. Patients with parathyroidectomy were found to have lower all-cause mortality (adjusted hazard ratio [aHR]: 0.34). Other independent predictors included age ≥ 65 years (aHR: 2.11) and diabetes mellitus (aHR: 3.80). For cardiovascular mortality, parathyroidectomy was associated with lower mortality (HR = 0.31) but with a marginal statistical significance (p = 0.061). In multivariate analysis, diabetes was the only significant predictor (aHR: 3.14). It is concluded that, for hemodialysis patients with parathyroid hormone concentrations greater than 800 pg/mL, parathyroidectomy is associated with reduced all-cause mortality.