55 research outputs found

    El gradiente radial de helio en la Vía Láctea

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    El objetivo fundamental de este trabajo de fin de Máster es el estudio de la distribución radial de helio en la Galaxia. Esto se determinaría con 37 espectros de una muestra de 23 nebulosas ionizadas distribuidas a diferentes distancias galactocéntricas. El rango espectral y la resolución de los espectros usados ha permitido observar una cantidad apreciable de líneas de recombinación de He I, óptimas para el cálculo de su abundancia. Se busca, además, explorar la dependencia que tiene la distribución radial de helio con las líneas usadas para la determinación de la abundancia de He+ y los factores de corrección por ionización (ICFs) usados. Esto permite analizar los procesos físicos presentes en la nebulosas que condicionan la determinación de He/H.In this Master’s thesis, to be able to study the radial distribution of helium in the Milky Way, we have worked with 37 spectra of 23 HII regions, covering a range of Galactocentric distance between 5 and 17 Kpc. The spectra sample has been obtained with three spectrographs: UVES from VLT, OSIRIS from GTC and MagE from The Clay Telescope. The analysed spectral ranges were 3100˚A-10400 ˚A for UVES, 3640˚A-7870˚A for OSIRIS and 3100˚A-10000˚A in the case of MagE. The spectral resolution and coverage allowed us to detect several He I recombination lines in each spectru

    The abundance discrepancy in ionized nebulae: which are the correct abundances?

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    Ionized nebulae are key to understanding the chemical composition and evolution of the Universe. Among these nebulae, H~{\sc ii} regions and planetary nebulae are particularly important as they provide insights into the present and past chemical composition of the interstellar medium, along with the nucleosynthetic processes involved in the chemical evolution of the gas. However, the heavy-element abundances derived from collisional excited lines (CELs) and recombination lines (RLs) do not align. This longstanding abundance-discrepancy problem calls into question our absolute abundance determinations. Which of the lines (if any) provides the correct heavy-element abundances? Recently, it has been shown that there are temperature inhomogeneities concentrated within the highly ionized gas of the H~{\sc ii} regions, causing the reported discrepancy. However, planetary nebulae do not exhibit the same trends as the H~{\sc ii} regions, suggesting a different origin for the abundance discrepancy. In this proceedings, we briefly discuss the state-of-the-art of the abundance discrepancy problem in both H~{\sc ii} regions and planetary nebulae.Comment: Submitted to the Proceedings of IAU Symposium 384: Planetary Nebulae: a Universal Toolbox in the Era of Precision Astrophysics. Eds: O. De Marco, A. Zijlstra, R. Szczerb

    Regeneration dynamics in the laurel forest: changes in species richness and composition

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    The recovery and survival of the Macaronesian laurel forest depends on its regeneration strategies. After years of long-term monitoring, both sexual and asexual regeneration appear to be equally important. However, the mechanisms for each are just beginning to be understood. In order to contribute to the understanding of the laurel forest sexual regeneration, we analyzed the species composition of the seedling bank every two weeks over three years in the laurel forest of Anaga (Tenerife, Canary Islands). We compared the species compositions of the seedling bank with the canopy, and analyzed changes in their diversity over this period in different forest stands. We found that species diversity (evenness) is different among plots regardless of the stand. In some cases, plot diversity remained constant over time, while others showed some variations, which were little related to climatic conditions (temperature and precipitation). We also found no relationship between the seedling bank and canopy composition, with shade-intolerant species being more abundant in the former. Although climatic conditions remained constant during the period and other environmental conditions did not vary either, some changes were found in the seedling bank species composition. These were related to the increased degree of conservation of the laurel forest of Anaga (by closing unpaved roads, limiting access, and the abandonment of agriculture) that had negatively affected the density of shade-intolerant species. We suggest that such conservation measures should be maintained and extended to other areas where agriculture has been recently abandoned to allow the potential establishment of laurel forest and late successional specie

    Usefulness of bone turnover markers as predictors of mortality risk, disease progression and skeletal-related events appearance in patients with prostate cancer with bone metastases following treatment with zoledronic acid: TUGAMO study

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    Owing to the limited validity of clinical data on the treatment of prostate cancer (PCa) and bone metastases, biochemical markers are a promising tool for predicting survival, disease progression and skeletal-related events (SREs) in these patients. The aim of this study was to evaluate the predictive capacity of biochemical markers of bone turnover for mortality risk, disease progression and SREs in patients with PCa and bone metastases undergoing treatment with zoledronic acid (ZA). Methods: This was an observational, prospective and multicenter study in which ninety-eight patients were included. Patients were treated with ZA (4mg every 4 weeks for 18 months). Data were collected at baseline and 3, 6, 9, 12, 15 and 18 months after the beginning of treatment. Serum levels of bone alkaline phosphtase (BALP), aminoterminal propeptide of procollagen type I (P1NP) and beta-isomer of carboxiterminal telopeptide of collagen I (b-CTX) were analysed at all points in the study. Data on disease progression, SREs development and survival were recorded. Results: Cox regression models with clinical data and bone markers showed that the levels of the three markers studied were predictive of survival time, with b-CTX being especially powerful, in which a lack of normalisation in visit 1 (3 months after the beginning of treatment) showed a 6.3-times more risk for death than in normalised patients. Levels of these markers were also predictive for SREs, although in this case BALP and P1NP proved to be better predictors. We did not find any relationship between bone markers and disease progression. Conclusion: In patients with PCa and bone metastases treated with ZA, b-CTX and P1NP can be considered suitable predictors for mortality risk, while BALP and P1NP are appropriate for SREs. The levels of these biomarkers 3 months after the beginning of treatment are especially importantThis study was supported by Novartis Oncology Spai

    Seven-versus 14-day course of antibiotics for the treatment of bloodstream infections by Enterobacterales: a randomized, controlled trial

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    [Objective] To prove that 7-day courses of antibiotics for bloodstream infections caused by members of the Enterobacterales (eBSIs) allow a reduction in patients' exposure to antibiotics while achieving clinical outcomes similar to those of 14-day schemes.[Methods] A randomized trial was performed. Adult patients developing eBSI with appropriate source control were assigned to 7 or 14 days of treatment, and followed 28 days after treatment cessation; treatments could be resumed whenever necessary. The primary endpoint was days of treatment at the end of follow-up. Clinical outcomes included clinical cure, relapse of eBSI and relapse of fever. A superiority margin of 3 days was set for the primary endpoint, and a non-inferiority margin of 10% was set for clinical outcomes. Efficacy and safety were assessed together with a DOOR/RADAR (desirability of outcome ranking and response adjusted for duration of antibiotic risk) analysis.[Results] 248 patients were assigned to 7 (n = 119) or 14 (n = 129) days of treatment. In the intention-to-treat analysis, median days of treatment at the end of follow-up were 7 and 14 days (difference 7, 95%CI 7–7). The non-inferiority margin was also met for clinical outcomes, except for relapse of fever (–0.2%, 95%CI –10.4 to 10.1). The DOOR/RADAR showed that 7-day schemes had a 77.7% probability of achieving better results than 14-day treatments.[Conclusions] 7-day schemes allowed a reduction in antibiotic exposure of patients with eBSI while achieving outcomes similar to those of 14-day schemes. The possibility of relapsing fever in a limited number of patients, without relevance to final outcomes, may not be excluded, but was overcome by the benefits of shortening treatments.This work received technical support from the Spanish Network of Research in Infectious Diseases (REIPI) and the Spanish Clinical Research Network (SCReN) of the Instituto de Salud Carlos III, Ministerio de Economía y Competitividad, Spanish Government (PT13/0002/0010).Peer reviewe

    Role of age and comorbidities in mortality of patients with infective endocarditis

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    [Purpose]: The aim of this study was to analyse the characteristics of patients with IE in three groups of age and to assess the ability of age and the Charlson Comorbidity Index (CCI) to predict mortality. [Methods]: Prospective cohort study of all patients with IE included in the GAMES Spanish database between 2008 and 2015.Patients were stratified into three age groups:<65 years,65 to 80 years,and ≥ 80 years.The area under the receiver-operating characteristic (AUROC) curve was calculated to quantify the diagnostic accuracy of the CCI to predict mortality risk. [Results]: A total of 3120 patients with IE (1327 < 65 years;1291 65-80 years;502 ≥ 80 years) were enrolled.Fever and heart failure were the most common presentations of IE, with no differences among age groups.Patients ≥80 years who underwent surgery were significantly lower compared with other age groups (14.3%,65 years; 20.5%,65-79 years; 31.3%,≥80 years). In-hospital mortality was lower in the <65-year group (20.3%,<65 years;30.1%,65-79 years;34.7%,≥80 years;p < 0.001) as well as 1-year mortality (3.2%, <65 years; 5.5%, 65-80 years;7.6%,≥80 years; p = 0.003).Independent predictors of mortality were age ≥ 80 years (hazard ratio [HR]:2.78;95% confidence interval [CI]:2.32–3.34), CCI ≥ 3 (HR:1.62; 95% CI:1.39–1.88),and non-performed surgery (HR:1.64;95% CI:11.16–1.58).When the three age groups were compared,the AUROC curve for CCI was significantly larger for patients aged <65 years(p < 0.001) for both in-hospital and 1-year mortality. [Conclusion]: There were no differences in the clinical presentation of IE between the groups. Age ≥ 80 years, high comorbidity (measured by CCI),and non-performance of surgery were independent predictors of mortality in patients with IE.CCI could help to identify those patients with IE and surgical indication who present a lower risk of in-hospital and 1-year mortality after surgery, especially in the <65-year group

    Desafíos en ciencia, tecnología e innovación en tiempo de Coronavirus Covid-19

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    El objetivo del presente estudio consistió en determinar el impacto de actividad física en la percepción de bienestar y salud en adolescentes, durante el periodo de confinamiento condicionado por la pandemia COVID-19. Se realizó un estudio observacional-longitudinal. N = 50 participantes (28 mujeres, 22 hombres; edad X = 15.12), quienes llevaron a cabo un programa de actividad física diseñado para espacios pequeños, además de realizar un pre y post-test. Los resultados muestran que hubo una mejora en la percepción de bienestar y salud después del periodo de actividad física (p=.05). Se concluye que, en la población de estudio, el programa de actividad física en espacios pequeños fue efectivo en la mejora de la percepción del bienestar y la salud

    Natural History of MYH7-Related Dilated Cardiomyopathy

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    BACKGROUND Variants in myosin heavy chain 7 (MYH7) are responsible for disease in 1% to 5% of patients with dilated cardiomyopathy (DCM); however, the clinical characteristics and natural history of MYH7-related DCM are poorly described. OBJECTIVES We sought to determine the phenotype and prognosis of MYH7-related DCM. We also evaluated the influence of variant location on phenotypic expression. METHODS We studied clinical data from 147 individuals with DCM-causing MYH7 variants (47.6% female; 35.6 +/- 19.2 years) recruited from 29 international centers. RESULTS At initial evaluation, 106 (72.1%) patients had DCM (left ventricular ejection fraction: 34.5% +/- 11.7%). Median follow-up was 4.5 years (IQR: 1.7-8.0 years), and 23.7% of carriers who were initially phenotype-negative developed DCM. Phenotypic expression by 40 and 60 years was 46% and 88%, respectively, with 18 patients (16%) first diagnosed at <18 years of age. Thirty-six percent of patients with DCM met imaging criteria for LV noncompaction. During follow-up, 28% showed left ventricular reverse remodeling. Incidence of adverse cardiac events among patients with DCM at 5 years was 11.6%, with 5 (4.6%) deaths caused by end-stage heart failure (ESHF) and 5 patients (4.6%) requiring heart transplantation. The major ventricular arrhythmia rate was low (1.0% and 2.1% at 5 years in patients with DCM and in those with LVEF of <= 35%, respectively). ESHF and major ventricular arrhythmia were significantly lower compared with LMNA-related DCM and similar to DCM caused by TTN truncating variants. CONCLUSIONS MYH7-related DCM is characterized by early age of onset, high phenotypic expression, low left ventricular reverse remodeling, and frequent progression to ESHF. Heart failure complications predominate over ventricular arrhythmias, which are rare. (C) 2022 The Authors. Published by Elsevier on behalf of the American College of Cardiology Foundation

    The SADDEN DEATH Study: Results from a Pilot Study in Non-ICU COVID-19 Spanish Patients

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    Introduction: The worldwide pandemic, coronavirus disease 2019 (COVID-19) is a novel infection with serious clinical manifestations, including death. Our aim is to describe the first non-ICU Spanish deceased series with COVID-19, comparing specifically between unexpected and expected deaths. Methods: In this single-centre study, all deceased inpatients with laboratory-confirmed COVID-19 who had died from March 4 to April 16, 2020 were consecutively included. Demographic, clinical, treatment, and laboratory data, were analyzed and compared between groups. Factors associated with unexpected death were identified by multivariable logistic regression methods. Results: In total, 324 deceased patients were included. Median age was 82 years (IQR 76–87); 55.9% males. The most common cardiovascular risk factors were hypertension (78.4%), hyperlipidemia (57.7%), and diabetes (34.3%). Other common comorbidities were chronic kidney disease (40.1%), chronic pulmonary disease (30.3%), active cancer (13%), and immunosuppression (13%). The Confusion, BUN, Respiratory Rate, Systolic BP and age ≥65 (CURB-65) score at admission was >2 in 40.7% of patients. During hospitalization, 77.8% of patients received antivirals, 43.3% systemic corticosteroids, and 22.2% full anticoagulation. The rate of bacterial co-infection was 5.5%, and 105 (32.4%) patients had an increased level of troponin I. The median time from initiation of therapy to death was 5 days (IQR 3.0–8.0). In 45 patients (13.9%), the death was exclusively attributed to COVID-19, and in 254 patients (78.4%), both COVID-19 and the clinical status before admission contributed to death. Progressive respiratory failure was the most frequent cause of death (92.0%). Twenty-five patients (7.7%) had an unexpected death. Factors independently associated with unexpected death were male sex, chronic kidney disease, insulin-treated diabetes, and functional independence. Conclusions: This case series provides in-depth characterization of hospitalized non-ICU COVID-19 patients who died in Madrid. Male sex, insulin-treated diabetes, chronic kidney disease, and independency for activities of daily living are predictors of unexpected death

    Outpatient Parenteral Antibiotic Treatment vs Hospitalization for Infective Endocarditis: Validation of the OPAT-GAMES Criteria

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