844 research outputs found

    Predicting Atrial Fibrillation Recurrence After Catheter Ablation Through Time Variability of P-wave Features

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    [EN] Nowadays, the first-line therapy for paroxysmal atrial fibrillation (PAF) is pulmonary vein isolation through catheter ablation. However, the success rate of this procedure is still not as high as desirable. Thus, preoperative prediction of early AF recurrence after ablation is a challenge to select optimal candidates for the intervention. To this end, some promising predictors based on the P-wave in short ECG signals have been proposed in the last years. However, evolution of the P-wave along the time has still not been analyzed. Hence, the present work studies how time variability of two features of the P-wave predicts midterm cryoablation failure. For 45 PAF patients, a standard 12-lead ECG signal was obtained for 5 minutes before ablation. An automatic algorithm was then used to delineate all P-waves in lead II, and duration and amplitude were computed. The resulting time series were characterized by their mean, standard deviation and coefficient of variation (CV). Correlating these measures with ablation outcome, the CV for both parameters obtained the best discrimination between patients. In fact, compared with the mean value, the CV for both features obtained accuracies 10% greater, thus achieving values of 70%. These outcomes entail that time variability of the P-wave can reveal new information about the proarrhythmic condition of the patients, thus improving predictions of ablation failure.Ruiz, A.; Arias, MA.; Puchol, A.; Pachon, MI.; Rieta, JJ.; Alcaraz, R. (2020). Predicting Atrial Fibrillation Recurrence After Catheter Ablation Through Time Variability of P-wave Features. IEEE. 1-4. https://doi.org/10.22489/CinC.2020.366S1

    Characterization and distribution of sedimentary facies of Cartagena Bay, Colombia.

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    En el análisis sedimentológico de 253 muestras de sedimentos de fondo y borde de playa de la Bahía de Cartagena, se identificaron 26 facies sedimentarias. Las muestras fueron tomadas con draga tipo Van Veen para el fondo, multimuestreador de sedimento tipo Beeker y apiques para los bordes de playa. Las muestras fueron tamizadas y se obtuvieron 15 categorías de acuerdo al tamaño de grano, posteriormente se realizó el análisis de carbonato de calcio (CaCO3) usando el calcímetro de Bernard. Los sedimentos fueron clasificados de acuerdo con el tamaño medio de grano y el contenido de CaCO3, para definir las facies sedimentarias existentes, donde la facies lodo litoclástico es la más representativa y se distribuye en la bahía interna y externa; al norte y sur de la Isla de Tierra Bomba. Se encontró que durante los últimos 30 años la distribución de las facies sedimentarias ha experimentado variaciones significativas: en la bahía interna ha disminuido el contenido de CaCO3 y al suroeste ha disminuido el tamaño de grano y el contenido de CaCO3; como resultado del creciente aporte de sedimentos del Canal de Dique y las condiciones oceanográficas presentes. Estas condiciones hidrodinámicas favorecen la meteorización y erosión de las formaciones coralinas presentes en el Caribe Colombiano.In the sedimentological analysis of 253 sediment samples from the edges and the bottom of the Cartagena bay, we identified 26 sedimentary facies. Samples were taken with Van Veen dredge for the bottom sediment Beeker multisampler and test pits for shorelines. Using the Bernard calcimeter we carried out the calcium carbonate (CaCO3) analysis in every sieved sample. Sediments were classified according to the average grain size and content of CaCO3, to define the existing sedimentary facies, where mud litoclast facies was the most representative and distributed to the north and south of the Tierra Bomba in the internal and external bay. We found that during the past 30 years the distribution of sedimentary facies has experienced significant changes: in the inner bay the content of CaCO3 has decreased and in the southwest the grain size and content of CaCO3 have decreased, as a result of the sediments contribution from Canal del Dique and present oceanographic conditions. These hydrodynamic conditions contribute to the weathering and erosion of coral formations present in the Colombian CaribbeanFil: Franco Arias, Diana Aillen. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Instituto Geológico del Sur; Argentina. Universidad Industrial de Santander; ColombiaFil: Restrepo López, J. C.. Universidad del Norte; ColombiaFil: Sanabria Ruiz, N. Y.. Universidad Industrial de Santander; ColombiaFil: Gutierrez, Julio C.. Centro de Investigaciones Oceanográficas e Hidrográficas; Colombi

    Evaluation of two MM5-PBL parameterizations for solar radiation and temperature estimation in the South-Eastern area of the Iberian Peninsula

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    We study the relative performance of two different MM5-PBL parameterizations (Blackadar and MRF) simulating hourly values of solar irradiance and temperature in the south-eastern part of the Iberian Peninsula. The evaluation was carried out throughout the different seasons of the year 2005 and for three different sky conditions: clear-sky, broken-clouds and overcast conditions. Two integrations, one per PBL parameterization, were carried out for every sky condition and season of the year and results were compared with observational data. Overall, the MM5 model, both using the Blackadar or MRF PBL parameterization, revealed to be a valid tool to estimate hourly values of solar radiation and temperature over the study area. The influence of the PBL parameterization on the model estimates was found to be more important for the solar radiation than for the temperature and highly dependent on the season and sky conditions. Particularly, a detailed analysis revealed that, during broken-clouds conditions, the ability of the model to reproduce hourly changes in the solar radiation strongly depends upon the selected PBL parameterization. Additionally, it was found that solar radiation RMSE values are about one order of magnitude higher during broken-clouds and overcast conditions compared to clear-sky conditions. For the temperature, the two PBL parameterizations provide very similar estimates. Only under overcast conditions and during the autumn, the MRF provides significantly better estimates

    Blood Pressure and Hypertension in Adults Permanently Living at High Altitude: A Systematic Review and Meta-Analysis.

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    Aryal, Nirmal, Mark Weatherall, Yadav Kumar Deo Bhatta, and Stewart Mann. Blood pressure and hypertension in adults permanently living at high altitude: a systematic review and meta-analysis. High Alt Med Biol. 17:185-193, 2016.-The objective of this study was to estimate the associations between altitude and mean blood pressure (BP) (or prevalence of hypertension [HT]) in adults who live permanently at high altitude. A literature search was conducted in December 2014 using PubMed, Scopus, and OvidSP (MedLine and EMBASE) databases to identify relevant observational studies. Inclusion criteria were reports of studies in populations permanently living at an altitude of ≥2400 m and in those 18 years or older. Meta-regression was used to estimate the association between average BP and HT and altitude. We identified 3375 articles and inclusion criteria were met for 21 reports, which included a total of 40,854 participants. Random-effects meta-regression estimated that for every 1000 m elevation the average systolic BP (SBP) (95% confidence interval [CI]) increased by 17 mmHg (0.2 to 33.8), p = 0.05 and diastolic BP (DBP) by 9.5 mmHg (0.6 to 18.4), p = 0.04 in participants with Tibetan origin. By contrast, in participants with non-Tibetan origin, average SBP decreased by 5.9 mmHg (-19.1 to 7.3), p = 0.38 and DBP by 4 mmHg (-13 to 5), p = 0.38. The odds ratios (95% CI) for the proportion of participants with HT per 1000 m increment in the altitude were 2.01 (0.37 to 11.02), p = 0.446 and 4.05 (0.07 to 244.69), p = 0.489 for Tibetan and non-Tibetan participants, respectively. Sensitivity analysis excluding two studies with older participants (≥60 years) reversed the direction of this effect in non-Tibetans with odds ratio (95% CI) of 0.10 (0.004 to 2.22) per 1000 m, p = 0.143. Overall, this review suggests weak association between BP and altitude in Tibetan origin populations

    Relationships between rhizosphere microbiota and forest health conditions in Pinus pinaster stands at the Iberian Peninsula

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    Producción CientíficaMaritime pine (Pinus pinaster) is a Mediterranean forest tree species of great ecological importance within the European Union and the Iberian Peninsula in particular, whose presence is seriously threatened by forest decline. Knowledge of the diversity, abundance, and functionality of rhizospheric microorganisms can provide important information in the design of new strategies for sustainable forest management against forest decline. In this work, rhizospheric samples were collected from representative pine forests in the region of Castilla y León (North-western Spain) (in 10 municipalities of 5 different provinces), analyzing different physicochemical parameters and bacterial and fungal biodiversity (by metabarcoding). In addition, different variables of tree health and climatic conditions were analyzed. The main phylum of microorganisms found in the rhizosphere of P. pinaster were the Ascomycota (54.5 %) and Acidobacteria (16.4 %) in fungi and bacteria, respectively. A clear relationship was found between the presence/absence of certain bacterial and fungal groups (taxonomic and functional) and the presence/absence of healthy/sick trees. Specifically, the fungal genus Umbelopsis and the bacterial genus Paenibacillus were thought as possible control agents of decline, as their presence was related to the absence of disease. Understanding the relationships between rhizosphere microbiota and forest health parameters in Pinus pinaster can be only achieved by exploring the complex ‘ecosystem microbiome’ and its functioning using focused, integrative microbiological and ecological research performed across multiple habitats

    Economic burden of age-related macular degeneration in routine clinical practice: the RAMDEBURS study

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    Purpose: To describe and evaluate the main direct health costs, in routine clinical practice, of age-related macular degeneration (AMD) patients, from hospital perspective, in Spain. Methods: Retrospective, multicenter, and observational study conducted on five third-level Spanish hospitals, between December 2018 and December 2019. The study included patients who were diagnosed of AMD before December 2018. Direct healthcare costs were obtained from a Spanish database. Study variables included demographic and clinical variables, and resources, such as treatment, diagnostic tests, medical examination, and surgery. Among the 1414 screened AMD patients, 1164 patients were included. In the overall study patients, the total cost was €5,386,511.0, with a mean cost per patient of €4627.6 ± 2383.9. The largest cost items were diagnostic examinations (€2.832.902,0) and vascular endothelial growth factor inhibitors (anti-VEGF) treatment (€2.038.257,2). Bevacizumab was administered to 325 (27.9%) patients, ranibizumab to 328 (28.2%), and aflibercept to 626 (53.8%); 115 (10.7%) patients received two anti-VEGF treatments, while 90 (7.7%) did not receive any. Over the course of the study, a total of 6,057 anti-VEGF injections were administered, with a mean (95% confidence interval) of 4.8 (4.4-5.2) injections per patient. Regarding safety, 29 patients experience injection-related adverse events, among them 12 patients had cataract and 11 ones elevated intraocular pressure (IOP). The incidence of endophthalmitis was 0.5% (6/1164). Conclusions: AMD was associated with considerable healthcare costs for regional healthcare systems. Diagnostic examinations, particularly OCT examinations, and anti-VEGF treatment represented the largest cost items

    Myopic maculopathy: Current status and proposal for a new classification and grading system (ATN)

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    Myopia is a highly frequent ocular disorder worldwide and pathologic myopia is the 4th most common cause of irreversible blindness in developed countries. Pathologic myopia is especially common in East Asian countries. Ocular alterations associated with pathologic myopia, especially those involving the macular area—defined as myopic maculopathy—are the leading causes of vision loss in patients with pathologic myopia. High myopia is defined as the presence of a highly negative refractive error (>−6 to −8 diopters) in the context of eye elongation (26–26.5 mm). Although the terms high myopia and pathologic myopia are often used interchangeably, they do not refer to the same eye disease. The two key factors driving the development of pathologic myopia are: 1) elongation of the axial length and 2) posterior staphyloma. The presence of posterior staphyloma, which is the most common finding in patients with pathologic myopia, is the key differentiating factor between high and pathologic myopia. The occurrence of staphyloma will, in most cases, eventually lead to other conditions such as atrophic, traction, or neovascular maculopathy. Posterior staphyloma is for instance, responsible for the differences between a myopic macular hole (MH)—with and without retinal detachment—and idiopathic MH. Posterior staphyloma typically induces retinal layer splitting, leading to foveoschisis in myopic MH, an important differentiating factor between myopic and emmetropic MH. Myopic maculopathy is a highly complex disease and current classification systems do not fully account for the numerous changes that occur in the macula of these patients. Therefore, a more comprehensive classification system is needed, for several important reasons. First, to more precisely define the disease stage to improve follow-up by enabling clinicians to more accurately monitor changes over time, which is essential given the progressive nature of this condition. Second, unification of the currently-available classification systems would establish standardized classification criteria that could be used to compare the findings from international multicentric studies. Finally, a more comprehensive classification system could help to improve our understanding of the genetic origins of this disease, which is clearly relevant given the interchangeable—but erroneous—use of the terms high and pathologic myopia in genetic researc

    Management of wet age-related macular degeneration in Spain: Challenges for treat and extend implementation in routine clinical practice

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    Purpose. To ascertain wet AMD (wAMD) management patterns in Spain. Methods. A two-round Delphi study conducted through a questionnaire-based survey designed from literature review and validated by an independent Steering Committee. Results. Forty-nine retina specialists experienced in wAMD participated by answering the two-round study questionnaire. Retina specialists are the main responsible for wAMD diagnosis and monitoring, including visits and associated procedures, with a median time per visit of 15 minutes. Standard treatment strategies are based on anti-VEGF administration, including standard loading dose administration followed by maintenance with aflibercept or ranibizumab (81% of patients). Although treat and extend (T&E) dosing strategy is considered as optimal for wAMD management (78% of the panelists), the main routine healthcare limitations (i.e., visits overload, reduced staff, short visit time, coordination issues, lack of facilities) conduct to self-defined “flexible” strategies, based on T&E and pro-re-nata (PRN) protocols. Conclusion. Proactive treatment patterns (T&E) are the preferred ones by the retina specialists in Spain. However, their proper implementation is difficult due to healthcare resource limitations, as well as organisation and logistic issues. .e use of anti-VEGF agents with longer duration of action could facilitate the use of strict T&E approaches according to routine clinical practicesThe study has been sponsored by Bayer Hispania S.L. Logistic

    Observation of spontaneous self-channelling of light in air below the collapse threshold

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    We report the observation of the self-guided propagation of 120 fs, 0.56 mJ infrared radiation in air for distances greater than one meter. In contrast to the known case of filamentation, in the present experiment the laser power is lower than the collapse threshold. Therefore the counter balance between Kerr self focussing and ionization induced defocussing as the stabilizing mechanism is ruled out. Instead, we find evidences of a process in which the transversal beam distribution reshapes into a form similar to a Townes soliton. We include numerical support for this conclusion
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