121 research outputs found

    Studies of an artificially generated electrode effect at ground level

    No full text
    International audienceThe outdoor experiments, using a metallic grid above the ground surface, have yielded well-defined vertical profiles of the space-charge density. The profiles showed strong evidence for the existence of an electrode effect, which could be named the artificial electrode effect and can serve as a very useful and well-controlled model for the study of atmospheric electric processes in the atmospheric surface layer. The build-up or break-down of an electrode-effect layer occurred in a time of the order of 10 s under the experimental conditions realized. The artificially generated electrode effect is dependent on the electrical field strength supplied, wind speed, turbulent mixing and ion mobilities. Wind speed and ion mobility seem to be the dominant factors, defining space-charge density profiles. A theoretical model for the artificial electrode effect has been developed, taking into account turbulent mixing of charged particles in the air flow with the logarithmic profile of the wind velocity. The numerical analysis of the boundary value problem for the two-dimensional equations for the light ion concentrations has been performed. The model presented shows a qualitative agreement of calculated space-charge profiles with measured ones, and explains the dependence of the artificial electrode effect on the dominant control parameters. The limiting conditions for the developed theory are discussed

    Steroid pulse -therapy in patients With coronAvirus Pneumonia (COVID-19), sYstemic inFlammation And Risk of vEnous thRombosis and thromboembolism (WAYFARER Study)

    Get PDF
    Introduction: Coronavirus pneumonia not only severely affects the lung tissue but is also associated with systemic autoimmune inflammation, rapid overactivation of cytokines and chemokines known as “cytokine storm”, and a high risk of thrombosis and thromboembolism. Since there is no specific therapy for this new coronavirus infection (COVID-19), searching for an effective and safe anti-inflammatory therapy is critical.Materials and Methods: This study evaluated efficacy and safety of pulse therapy with high doses of glucocorticosteroids (GCS), methylprednisolone 1,000 mg for 3 days plus dexamethasone 8 mg for another 3-5 days, in 17 patients with severe coronavirus pneumonia as a part of retrospective comparative analysis (17 patients in control group). The study primary endpoint was the aggregate dynamics of patients’ condition as evaluated by an original CCS-COVID scale, which included, in addition to the clinical status, assessments of changes in the inflammation marker, C-reactive protein (CRP); the thrombus formation marker, D-dimer; and the extent of lung injury evaluated by computed tomography (CT). Patients had signs of lung injury (53.2 % and 25.6 %), increases in CRP 27 and 19 times, and a more than doubled level of D-dimer (to 1.41 µg/ml and 1.15 µg/ml) in the active therapy and the control groups, respectively. The GCS treatment group had a more severe condition at baseline.Results: The GCS pulse therapy proved effective and significantly decreased the CCS-COVID scores. Median score difference was 5.00 compared to the control group (р=0.011). Shortness of breath considerably decreased; oxygen saturation increased, and the NEWS-2 clinical status scale scores decreased. In the GCS group, concentration of CRP significantly decreased from 134 mg/dl to 41.8 mg/dl (р=0.009) but at the same time, D-dimer level significantly increased from 1.41 µg/ml to 1.98 µg/ml (р=0.044). In the control group, the changes were nonsignificant. The dynamics of lung injury by CT was better in the treatment group but the difference did not reach a statistical significance (р=0.062). Following the GCS treatment, neutrophilia increased (р=0.0001) with persisting lymphopenia, and the neutrophil/lymphocyte (N/L) ratio, a marker of chronic inflammation, increased 2.5 times (р=0.006). The changes in the N/L ratio and D-dimer were found to correlate in the GCS pulse therapy group (r =0.49, p=0.04), which underlined the relationship of chronic autoimmune inflammation with thrombus formation in COVID-19. No significant changes were observed in the control group. In result, four patients developed venous thromboembolic complications (two of them had pulmonary artery thromboembolism) after the GCS pulse therapy despite the concomitant antiplatelet treatment at therapeutic doses. Recovery was slower in the hormone treatment group (median stay in the hospital was 26 days vs 18 days in the control group, р=0.001).Conclusion: Pulse therapy with high doses of GCS exerted a rapid anti-inflammatory effect but at the same time, increased the N/L ratio and the D-dimer level, which increased the risk of thromboembolism

    Pan-Eurasian Experiment (PEEX): Towards a holistic understanding of the feedbacks and interactions in the land-Atmosphere-ocean-society continuum in the northern Eurasian region

    Get PDF
    The northern Eurasian regions and Arctic Ocean will very likely undergo substantial changes during the next decades. The Arctic-boreal natural environments play a crucial role in the global climate via albedo change, carbon sources and sinks as well as atmospheric aerosol production from biogenic volatile organic compounds. Furthermore, it is expected that global trade activities, demographic movement, and use of natural resources will be increasing in the Arctic regions. There is a need for a novel research approach, which not only identifies and tackles the relevant multi-disciplinary research questions, but also is able to make a holistic system analysis of the expected feedbacks. In this paper, we introduce the research agenda of the Pan-Eurasian Experiment (PEEX), a multi-scale, multi-disciplinary and international program started in 2012 (https://www.atm.helsinki.fi/peex/). PEEX sets a research approach by which large-scale research topics are investigated from a system perspective and which aims to fill the key gaps in our understanding of the feedbacks and interactions between the land-Atmosphere-Aquatic-society continuum in the northern Eurasian region. We introduce here the state of the art for the key topics in the PEEX research agenda and present the future prospects of the research, which we see relevant in this context

    Patients with a Combination of Atrial Fibrillation and Chronic Heart Failure in Clinical Practice: Comorbidities, Drug Treatment and Outcomes

    Get PDF
    Aim. To assess in clinical practice the structure of multimorbidity, cardiovascular pharmacotherapy and outcomes in patients with a combination of atrial fibrillation (AF) and chronic heart failure (CHF) based on prospective registries of patients with cardiovascular diseases (CVD).Materials and Methods. The data of 3795 patients with atrial fibrillation (AF) were analyzed within the registries RECVASA (Ryazan), RECVASA FP (Moscow, Kursk, Tula, Yaroslavl), REGION-PO and REGION-LD (Ryazan), REGION-Moscow, REGATA (Ryazan). The comparison groups consisted of 3016 (79.5%) patients with AF in combination with CHF and 779 (29.5%) patients with AF without CHF. The duration of prospective observation is from 2 to 6 years.Results. Patients with a combination of AF and CHF (n=3016, age was 72.0±10.3 years; 41.8% of men) compared with patients with AF without CHF (n=779, age was 70.3±12.0 years; 43.5% of men) had a higher risk of thromboembolic complications (CHA2DS2-VASc – 4.68±1.59 and 3.10±1.50; p<0.001) and hemorrhagic complications (HAS-BLED – 1.59±0.77 and 1.33±0.76; p<0.05). Patients with a combination of AF and CHF significantly more often (p<0.001) than in the absence of CHF were diagnosed with arterial hypertension (93.9% and 83.8%), coronary heart disease (87.9% and 53,5%), myocardial infarction (28.4% and 14.0%), diabetes mellitus (22.4% and 7.7%), chronic kidney disease (24.8% and 16.2%), as well as respiratory diseases (20.1% and 15.3%; p=0.002). Patients with AF in the presence of CHF, compared with patients without CHF, were more often diagnosed with a permanent form of arrhythmia (49.3% and 32.9%; p<0.001) and less often paroxysmal (22.5% and 46.2%; p<0.001) form  of  arrhythmia.  Ejection  fraction  ≤40%  (9.3%  and  1.2%;  p<0.001),  heart  rate  ≥90/min  (23.7% and 19.3%; p=0.008) and blood pressure ≥140/90 mm Hg (59.9% and 52.2%; p<0.001) were recorded with AF in the presence of CHF more often than in the absence of CHF. The frequency of proper cardiovascular pharmacotherapy was higher, albeit insufficient, in the presence of CHF (64.9%) than in the absence of it (56.1%), but anticoagulants were prescribed less frequently when AF and CHF were combined (38.8% and  49, 0%; p<0.001). The frequency of unreasonable prescription of antiplatelet agents instead of anticoagulants was 52.5% and 33.3% (p<0.001) in the combination of AF, CHF and coronary heart disease, as well as in the combination of AF with coronary heart disease but without CHF. Patients with AF and CHF during the observation period compared with those without CHF had higher mortality from all causes (37.6% and 30.3%; p=0.001), the frequency of non-fatal cerebral stroke (8.2% and 5.4%; p=0.032) and myocardial infarction (4.7% and 2.5%; p=0.036), hospitalizations for CVD (22.8% and 15.5%; p<0.001).Conclusion. Patients with a combination of AF and CHF, compared with the group of patients with AF without CHF, were older, had a higher risk of thromboembolic and hemorrhagic complications, they were more often diagnosed with other concomitant cardiovascular and chronic noncardiac diseases, decreased left ventricular ejection fraction, tachysystole, failure to achieve the target blood pressure level in the presence of arterial hypertension. The frequency of prescribing proper cardiovascular pharmacotherapy was higher, albeit insufficient, in the presence of CHF, while the frequency of prescribing anticoagulants was less. The  incidence of mortality from all causes, the development of non-fatal myocardial infarction   and cerebral stroke, as well as the incidence of hospitalizations for CVDs were higher in AF associated with CHF

    The additional value of patient-reported health status in predicting 1-year mortality after invasive coronary procedures: A report from the Euro Heart Survey on Coronary Revascularisation

    Get PDF
    Objective: Self-perceived health status may be helpful in identifying patients at high risk for adverse outcomes. The Euro Heart Survey on Coronary Revascularization (EHS-CR) provided an opportunity to explore whether impaired health status was a predictor of 1-year mortality in patients with coronary artery disease (CAD) undergoing angiographic procedures. Methods: Data from the EHS-CR that included 5619 patients from 31 member countries of the European Society of Cardiology were used. Inclusion criteria for the current study were completion of a self-report measure of health status, the EuroQol Questionnaire (EQ-5D) at discharge and information on 1-year follow-up, resulting in a study population of 3786 patients. Results: The 1-year mortality was 3.2% (n = 120). Survivors reported fewer problems on the five dimensions of the EQ-5D as compared with non-survivors. A broad range of potential confounders were adjusted for, which reached a p<0.10 in the unadjusted analyses. In the adjusted analyses, problems with self-care (OR 3.45; 95% CI 2.14 to 5.59) and a low rating (≤ 60) on health status (OR 2.41; 95% CI 1.47 to 3.94) were the most powerful independent predictors of mortality, among the 22 clinical variables included in the analysis. Furthermore, patients who reported no problems on all five dimensions had significantly lower 1-year mortality rates (OR 0.47; 95% CI 0.28 to 0.81). Conclusions: This analysis shows that impaired health status is associated with a 2-3-fold increased risk of all-cause mortality in patients with CAD, independent of other conventional risk factors. These results highlight the importance of including patients' subjective experience of their own health status in the evaluation strategy to optimise risk stratification and management in clinical practice

    Effect of Systemic Hypertension With Versus Without Left Ventricular Hypertrophy on the Progression of Atrial Fibrillation (from the Euro Heart Survey).

    Get PDF
    Hypertension is a risk factor for both progression of atrial fibrillation (AF) and development of AF-related complications, that is major adverse cardiac and cerebrovascular events (MACCE). It is unknown whether left ventricular hypertrophy (LVH) as a consequence of hypertension is also a risk factor for both these end points. We aimed to assess this in low-risk AF patients, also assessing gender-related differences. We included 799 patients from the Euro Heart Survey with nonvalvular AF and a baseline echocardiogram. Patients with and without hypertension were included. End points after 1 year were occurrence of AF progression, that is paroxysmal AF becoming persistent and/or permanent AF, and MACCE. Echocardiographic LVH was present in 33% of 379 hypertensive patients. AF progression after 1 year occurred in 10.2% of 373 patients with rhythm follow-up. In hypertensive patients with LVH, AF progression occurred more frequently as compared with hypertensive patients without LVH (23.3% vs 8.8%, p = 0.011). In hypertensive AF patients, LVH was the most important multivariably adjusted determinant of AF progression on multivariable logistic regression (odds ratio 4.84, 95% confidence interval 1.70 to 13.78, p = 0.003). This effect was only seen in male patients (27.5% vs 5.8%, p = 0.002), while in female hypertensive patients, no differences were found in AF progression rates regarding the presence or absence of LVH (15.2% vs 15.0%, p = 0.999). No differences were seen in MACCE for hypertensive patients with and without LVH. In conclusion, in men with hypertension, LVH is associated with AF progression. This association seems to be absent in hypertensive women

    Progression From Paroxysmal to Persistent Atrial Fibrillation. Clinical Correlates and Prognosis

    Get PDF
    Objectives: We investigated clinical correlates of atrial fibrillation (AF) progression and evaluated the prognosis of patients demonstrating AF progression in a large population. Background: Progression of paroxysmal AF to more sustained forms is frequently seen. However, not all patients will progress to persistent AF. Methods: We included 1,219 patients with paroxysmal AF who participated in the Euro Heart Survey on AF and had a known rhythm status at follow-up. Patients who experienced AF progression after 1 year of follow-up were identified. Results: Progression of AF occurred in 178 (15%) patients. Multivariate analysis showed that heart failure, age, previous transient ischemic attack or stroke, chronic obstructive pulmonary disease, and hypertension were the only independent predictors of AF progression. Using the regression coefficient as a benchmark, we calculated the HATCH score. Nearly 50% of the patients with a HATCH score &gt;5 progressed to persistent AF compared with only 6% of the patients with a HATCH score of 0. During follow-up, patients with AF progression were more often admitted to the hospital and had more major adverse cardiovascular events. Conclusions: A substantial number of patients progress to sustained AF within 1 year. The clinical outcome of these patients regarding hospital admissions and major adverse cardiovascular events was worse compared with patients demonstrating no AF progression. Factors known to cause atrial structural remodeling (age and underlying heart disease) were independent predictors of AF progression. The HATCH score may help to identify patients who are likely to progress to sustained forms of AF in the near future. \ua9 2010 American College of Cardiology Foundation
    corecore