77 research outputs found

    Development and validation of explainable machine learning models for risk of mortality in transcatheter aortic valve implantation: TAVI risk machine scores.

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    AIMS Identification of high-risk patients and individualized decision support based on objective criteria for rapid discharge after transcatheter aortic valve implantation (TAVI) are key requirements in the context of contemporary TAVI treatment. This study aimed to predict 30-day mortality following TAVI based on machine learning (ML) using data from the German Aortic Valve Registry. METHODS AND RESULTS Mortality risk was determined using a random forest ML model that was condensed in the newly developed TAVI Risk Machine (TRIM) scores, designed to represent clinically meaningful risk modelling before (TRIMpre) and in particular after (TRIMpost) TAVI. Algorithm was trained and cross-validated on data of 22 283 patients (729 died within 30 days post-TAVI) and generalisation was examined on data of 5864 patients (146 died). TRIMpost demonstrated significantly better performance than traditional scores [C-statistics value, 0.79; 95% confidence interval (CI)] [0.74; 0.83] compared to Society of Thoracic Surgeons (STS) with C-statistics value 0.69; 95%-CI [0.65; 0.74]). An abridged (aTRIMpost) score comprising 25 features (calculated using a web interface) exhibited significantly higher performance than traditional scores (C-statistics value, 0.74; 95%-CI [0.70; 0.78]). Validation on external data of 6693 patients (205 died within 30 days post-TAVI) of the Swiss TAVI Registry confirmed significantly better performance for the TRIMpost (C-statistics value 0.75, 95%-CI [0.72; 0.79]) compared to STS (C-statistics value 0.67, CI [0.63; 0.70]). CONCLUSION TRIM scores demonstrate good performance for risk estimation before and after TAVI. Together with clinical judgement, they may support standardised and objective decision-making before and after TAVI

    Atrial septal defect in adults is associated with airway hyperresponsiveness

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    Objective: The association between secundum atrial septal defects (ASD) and asthma-like dyspnea with consequent long-term pulmonary inhalant use, is poorly understood in adult ASD patients. Airway hyperresponsiveness is suggested to be the underlying mechanism of cardiac asthma from mitral valve disease and ischemic cardiomyopathy. We hypothesized that airway hyperresponsiveness may also be found in adult ASD patients. Our aim was to study airway responsiveness in adult ASD patients before percutaneous closure and at short-and long-term postprocedural follow-up. Methods: This prospective study included 31 ASD patients (65% female, mean age 49 ± 15y) who underwent spirometry and bronchoprovocation testing pre-and six-month postprocedurally, with additional bronchoprovocation at 2-year follow-up. Airway hyperresponsiveness was defined as ≄20% fall of forced expiratory volume in 1-second (FEV1) following <8.0 mg/mL of inhaled methacholine. Results: Airway hyperresponsiveness was found in 19/30 patients (63%[95%CI 45%-81%]; post hoc statistical power = 89%). Asthma-like symptoms wheezing, chest tightness, and cough were more frequently reported in airway hyperresponsive patients. Airway responsiveness was not influenced by successful percutaneous ASD closure, corresponding to persistence of asthma-like symptoms postclosure. Regardless of airway responsiveness, postprocedural right-sided reverse remodeling significantly improved dyspnea and pulmonary function. Conclusions: This study is the first to report a high prevalence of airway hyperresponsiveness in a cohort of unrepaired adult ASD patients, and confirms the association between asthma-like symptoms and ASD in adults. Attention to symptoms and pulmonary function should be given during clinical follow-up of adult ASD patients, both before and long after repair

    An open-label pilot study of the effectiveness of adalimumab in patients with rheumatoid arthritis and previous infliximab treatment: relationship to reasons for failure and anti-infliximab antibody status

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    This prospective open-label pilot study evaluated the effectiveness and safety of adalimumab and the relationship to antibodies against infliximab (IFX) in adult patients with active rheumatoid arthritis (RA) who had been treated previously with IFX and experienced treatment failure owing to lack or loss of response or intolerance. Patients self-administered adalimumab 40 mg subcutaneously every other week for 16 weeks, followed by maintenance therapy for up to Week 56. Measures of effectiveness included American College of Rheumatology (ACR) and European League Against Rheumatism (EULAR) response criteria, 28-joint Disease Activity Score, and the Health Assessment Questionnaire Disability Index. Serum IFX concentrations, human antichimeric antibody against IFX (HACA), adalimumab serum concentrations, antiadalimumab antibody, and safety also were assessed. Of the 41 enrolled patients, 37 completed 16 weeks and 30 completed 56 weeks of treatment. Patients experienced clinically meaningful improvements in all measures of RA activity, with greater response rates observed for patients who had experienced loss of initial response to or intolerance of IFX. At Week 16, 46% of patients achieved an ACR20 and 28% achieved an ACR50; 61% achieved an at least moderate and 17% achieved a good EULAR response. Clinical benefit was maintained through Week 56 in all effectiveness parameters. Baseline HACA status did not significantly impact effectiveness. No new safety signals were observed; neither former IFX intolerance status nor baseline HACA status had a clinically relevant impact on adverse event frequency or severity. Adalimumab was effective and well-tolerated in patients with RA who previously failed IFX therapy, irrespective of reason for discontinuation and of HACA status

    AMBER : a near infrared focal instrument for the VLTI

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    10 pagesInternational audienceAMBER is the General User near-infrared focal instrument of the Very Large Telescope interferometer. Its specifications are based on three key programs on Young Stellar Objects, Active Galactic Nuclei central regions, masses and spectra of hot Extra Solar Planets. It has an imaging capacity because it combines up to three beams and very high accuracy measurement are expected from the spatial filtering of beams by single mode fibers and the comparison of measurements made simultaneously in different spectral channels

    Tema 14: Aglomerados de estrelas

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    We present observations of the symbiotic star CH Cyg with a new JHK-band beam combiner mounted to the IOTA interferometer. The new beam combiner consists of an anamorphic cylindrical lens system and a grism, and allows the simultaneous recording of spectrally dispersed J-, H- and K-band Michelson interferograms. The observations of CH Cyg were conducted on 5, 6, 8 and 11 June 2001 using baselines of 17m to 25m. From the interferograms of CH Cyg, J-, H-, and K-band visibility functions can be determined. Uniform-disk fits to the visibilities give, e.g., stellar diameters of (7.8 ± 0.6) mas and (8.7 ± 0.8) mas in H and K, respectively. Angular stellar filter radii and Rosseland radii are derived from the measured visibilities by fitting theoretical center-to-limb intensity variations (CLVs) of Mira star models. The available HIPPARCOS parallax of CH Cyg allows us to determine linear radii. For example, on the basis of the K-band visibility, Rosseland radii in the range of 214 to 243 solar radii can be derived utilizing CLVs of different fundamental mode Mira models as fit functions. These radii agree well within the error bars with the corresponding theoretical model Rosseland radii of 230 to 282 solar radii. Models of first overtone pulsators are not in good agreement with the observations. The wavelength dependence of the stellar diameter can be well studied by using visibility ratios V(λ1)/V(λ2) since ratios of visibilities of different spectral channels can be measured with higher precision than absolute visibilities. We found that the 2.03 Όm uniform disk diameter of CH Cyg is approximately 1.1 times larger than the 2.15 Όm and 2.26 Όm uniform-disk diameter

    TRY plant trait database – enhanced coverage and open access

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    Plant traits - the morphological, anatomical, physiological, biochemical and phenological characteristics of plants - determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait‐based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits - almost complete coverage for ‘plant growth form’. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait–environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives
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