337 research outputs found
Satellite-based detection of volcanic sulphur dioxide from recent eruptions in Central and South America
Volcanic eruptions can emit large amounts of rock fragments and fine particles (ash) into the atmosphere, as well as several gases, including sulphur dioxide (SO<sub>2</sub>). These ejecta and emissions are a major natural hazard, not only to the local population, but also to the infrastructure in the vicinity of volcanoes and to aviation. Here, we describe a methodology to retrieve quantitative information about volcanic SO<sub>2</sub> plumes from satellite-borne measurements in the UV/Visible spectral range. The combination of a satellite-based SO<sub>2</sub> detection scheme and a state-of-the-art 3D trajectory model enables us to confirm the volcanic origin of trace gas signals and to estimate the plume height and the effective emission height. This is demonstrated by case-studies for four selected volcanic eruptions in South and Central America, using the GOME, SCIAMACHY and GOME-2 instruments
Nationwide Real-world Cohort Study of First-line Tyrosine Kinase Inhibitor Treatment in Epidermal Growth Factor Receptor-mutated Non-small-cell Lung Cancer
Most trials regarding tyrosine kinase inhibitors in patients with advanced epidermal growth factor receptor-mutated non-small-cell lung cancer comprised selected series from Asian populations. We found that Western European patients with epidermal growth factor receptor-mutated non-small-cell lung cancer who received first-line treatment with regular tyrosine kinase inhibitors have a median overall survival of 20.2 months in our large nationwide real-world cohort. In patients with brain metastasis, erlotinib showed superior results compared with gefitinib and was similar to afatinib. Background: Only a few randomized trials directly compared the relative efficacy of tyrosine kinase inhibitors (TKIs) in patients with advanced epidermal growth factor receptor (EGFR)-mutated non-small-cell lung cancer (NSCLC), and most trials comprised selected series from Asian populations. Therefore, the aim of this study was to assess the overall survival (OS) of advanced EGFR-mutated NSCLC in a large white population and to evaluate variation between different TKIs and identify predictors of survival. Patients and Methods: Information about clinical characteristics, treatment, and survival for 873 patients with stage IV EGFR + NSCLC, diagnosed from 2015 through 2017, was derived from the Netherlands Cancer Registry. OS was evaluated by actuarial analysis and multivariable Cox regression. Prognostic factors are reported as hazard ratios and 95% confidence intervals. Results: A total of 596 (68%) patients received first-line treatment with regular TKIs, providing a median survival of 20.2 months. Forty-five percent of patients were 70 years and older, and 54% of patients had distant metastasis in multiple organs. In the multivariate analysis, survival was significantly worse for men, and patients with higher age, poorer performance, and >= 3 organs with metastasis. Compared with erlotinib, OS was worse for gefitinib users (adjusted hazard ratio, 1.30; 95% confidence interval, 1.02-1.64), predominantly in patients with brain metastasis. Conclusion: Dutch patients with EGFR-mutated NSCLC who received first-line treatment with regular TKIs have a median OS of 20.2 months in a nationwide real-world cohort. In patients with brain metastasis, erlotinib showed superior results compared with gefitinib and was similar to afatinib. (C) 2020 Elsevier Inc. All rights reserved
Duration and compliance with antidepressant treatment in immigrant and native-born populations in Spain: a four year follow-up descriptive study
<p>Abstract</p> <p>Background</p> <p>Non-compliance with antidepressant treatment continues to be a complex problem in mental health care. In immigrant populations non-compliance is one of several barriers to adequate management of mental illness; some data suggest greater difficulties in adhering to pharmacological treatment in these groups and an increased risk of therapeutic failure.</p> <p>The aim of this study is to assess differences in the duration and compliance with antidepressant treatment among immigrants and natives in a Spanish health region.</p> <p>Methods</p> <p>Population-based (n=206,603), retrospective cohort study including all subjects prescribed ADT between 2007 and 2009 and recorded in the national pharmacy claims database. Compliance was considered adequate when the duration was longer than 4months and when patients withdrew more than 80% of the packs required.</p> <p>Results</p> <p>5334 subjects (8.5% of them being immigrants) initiated ADT. Half of the immigrants abandoned treatment during the second month (median for natives=3months). Of the immigrants who continued, only 29.5% presented good compliance (compared with 38.8% in natives). The estimated risk of abandoning/ending treatment in the immigrant group compared with the native group, adjusted for age and sex, was 1.28 (95%CI 1.16-1.42).</p> <p>Conclusions</p> <p>In the region under study, immigrants of all origins present higher percentages of early discontinuation of ADT and lower median treatment durations than the native population. Although this is a complex, multifactor situation, the finding of differences between natives and immigrants in the same region suggests the need to investigate the causes in greater depth and to introduce new strategies and interventions in this population group.</p
Statistical dynamo theory: Mode excitation
We compute statistical properties of the lowest-order multipole coefficients
of the magnetic field generated by a dynamo of arbitrary shape. To this end we
expand the field in a complete biorthogonal set of base functions, viz. B =
sum_k a^k(t) b^k(r). We consider a linear problem and the statistical
properties of the fluid flow are supposed to be given. The turbulent convection
may have an arbitrary distribution of spatial scales. The time evolution of the
expansion coefficients a^k(t) is governed by a stochastic differential equation
from which we infer their averages , autocorrelation functions <a^k(t)
a^{k*}(t+tau)>, and an equation for the cross correlations . The
eigenfunctions of the dynamo equation (with eigenvalues lambda_k) turn out to
be a preferred set in terms of which our results assume their simplest form.
The magnetic field of the dynamo is shown to consist of transiently excited
eigenmodes whose frequency and coherence time is given by Im(lambda_k) and
-1/(Re lambda_k), respectively. The relative r.m.s. excitation level of the
eigenmodes, and hence the distribution of magnetic energy over spatial scales,
is determined by linear theory. An expression is derived for /
in case the fundamental mode b^0 has a dominant amplitude, and we
outline how this expression may be evaluated. It is estimated that
/ ~ 1/N where N is the number of convective cells in the
dynamo. We show that the old problem of a short correlation time (or FOSA) has
been partially eliminated. Finally we prove that for a simple statistically
steady dynamo with finite resistivity all eigenvalues obey Re(lambda_k) < 0.Comment: 14 pages, 2 figures. Accepted for publication in Physical Review
Mild hyperlipidemia in mice aggravates platelet responsiveness in thrombus formation and exploration of platelet proteome and lipidome.
Hyperlipidemia is a well-established risk factor for cardiovascular diseases. Millions of people worldwide display mildly elevated levels of plasma lipids and cholesterol linked to diet and life-style. While the prothrombotic risk of severe hyperlipidemia has been established, the effects of moderate hyperlipidemia are less clear. Here, we studied platelet activation and arterial thrombus formation in Apoe-/- and Ldlr-/- mice fed a normal chow diet, resulting in mildly increased plasma cholesterol. In blood from both knockout mice, collagen-dependent thrombus and fibrin formation under flow were enhanced. These effects did not increase in severe hyperlipidemic blood from aged mice and upon feeding a high-fat diet (Apoe-/- mice). Bone marrow from wild-type or Ldlr-/- mice was transplanted into irradiated Ldlr-/- recipients. Markedly, thrombus formation was enhanced in blood from chimeric mice, suggesting that the hyperlipidemic environment altered the wild-type platelets, rather than the genetic modification. The platelet proteome revealed high similarity between the three genotypes, without clear indication for a common protein-based gain-of-function. The platelet lipidome revealed an altered lipid profile in mildly hyperlipidemic mice. In conclusion, in Apoe-/- and Ldlr-/- mice, modest elevation in plasma and platelet cholesterol increased platelet responsiveness in thrombus formation and ensuing fibrin formation, resulting in a prothrombotic phenotype
Health status and psychological outcomes after trauma: A prospective multicenter cohort study
Introduction Survival after trauma has considerably improved. This warrants research on non-fatal outcome. We aimed to identify characteristics associated with both short and long-term health status (HS) after trauma and to describe the recovery patterns of HS and psychological outcomes during 24 months of follow-up. Methods Hospitalized patients with all types of injuries were included. Data were collected at 1 week 1, 3, 6, 12, and 24 months post-trauma. HS was assessed with the EuroQol-5D-3L (EQ-5D3L) and the Health Utilities Index Mark 2 and 3 (HUI2/3). For the screening of symptoms of post-traumatic stress, anxiety and depression, the Impact of Event Scale (IES) and the Hospital Anxiety and Depression Scale (HADS) subscale anxiety (HADSA) and subscale depression (HADSD) were used. Recovery patterns of HS and psychological outcomes were examined with linear mixed model analyses. Results A total of 4,883 patients participated (median age 68 (Interquartile range 53–80); 50% response rate). The mean (Standard Deviation (SD)) pre-injury EQ-5D-3L score was 0.85 (0.23). One week post-trauma, mean (SD) EQ-5D-3L, HUI2 and HUI3 scores were 0.49 (0.32), 0.61 (0.22) and 0.38 (0.31), respectively. These scores significantly improved to 0.77 (0.26), 0.77 (0.21) and 0.62 (0.35), respectively, at 24 months. Most recovery occurred up until 3 months. At long-term follow-up, patients of higher age, with comorbidities, longer hospital stay, lower extremity fracture and spine injury showed lower HS. The mean (SD) scores of the IES, HADSA and HADSD were respectively 14.80 (15.80), 4.92 (3.98) and 5.00 (4.28), respectively, at 1 week post-trauma and slightly improved over 24 months post-trauma to 10.35 (14.72), 4.31 (3.76) and 3.62 (3.87), respectively. Discussion HS and psychological symptoms improved over time and most improvements occurred within 3 months post-trauma. The effects of severity and type of injury faded out over time. Patients frequently reported symptoms of post-traumatic stress. Trial registration ClinicalTrials.gov identifier: NCT02508675
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