851 research outputs found

    Preoperative and postoperative evaluation of airways compression in pediatric patients with 3-dimensional multislice computed tomographic scanning: Effect on surgical management

    Get PDF
    ObjectivesSurgical management of airway compression of vascular origin requires an accurate analysis of anatomy and various mechanisms of compression. This study assessed the usefulness of 3-dimensional computed tomographic scanning in the preoperative and postoperative evaluation of airways compression in a pediatric population.MethodsThirty-seven consecutive patients (median age, 4 months) were examined with multislice 3-dimensional computed tomographic scanning: 18 patients before surgical treatment of anomalies of vascular rings, 2 patients because of respiratory symptoms after repair of esophageal atresia, and 17 patients because of persisting respiratory symptoms or prolonged mechanical ventilation after cardiac surgery for congenital heart disease.ResultsThe procedure was successful, with high-quality diagnostic imaging obtained in all cases without any complications. The anatomy and relationship between the vascular arches and airways was analyzed in all referred patients with vascular arch anomalies confirmed on the basis of the surgical findings, and this helped the surgeon to plan the procedure and choose the best approach. After cardiac surgery, the airway and vascular structures involved and the mechanism of compression were specified in all but one case, and the 3-dimensional computed tomographic scan serves as an important tool for deciding whether to perform reoperation on patients requiring prolonged mechanical ventilation.ConclusionThree-dimensional computed tomographic scanning is a safe, fast, and noninvasive method useful for accurately analyzing the mechanisms of airway compression of vascular origin and thus possible improving the surgical management of pediatric patients

    Benefit of dual-chamber pacing with Closed Loop Stimulation in tilt-induced cardio-inhibitory reflex syncope (BIOSync trial): study protocol for a randomized controlled trial

    Get PDF
    Ritme cardíac; Síncope reflex neurològic; Prova de la taula d’inclinacióRitmo cardíaco; Síncope reflejo neuromediado; Prueba de la mesa inclinadaCardiac pacing; Neuro-mediated reflex syncope; Tilt-Table testBackground: The efficacy of dual-chamber cardiac pacing in neuro-mediated reflex syncope with a cardio-inhibitory response to the Tilt-Table test (TT) has not been definitively assessed so far. The lack of reproducibility of results from previous studies may be partially explained by discrepancies in subject selection and some weaknesses in design and methods. The European Society of Cardiology (ESC) has set a class IIb indication to pacemaker implantation in this population recommending further research. Methods/design: The BIOSync study is a multicenter, patient- and outcome-assessor-blind, randomized, parallel-arm, placebo-controlled trial with the objective of assessing the clinical benefit of cardiac pacing in patients with frequently recurrent reflex syncope, suspected (but not proven) to be triggered by asystolic pauses as showing a VASIS 2B response to the TT (>3-s pause regardless of blood pressure drop). The primary and secondary endpoints are time to first post-implantation recurrence of syncope or the combination of pre-syncope or syncope, respectively. One hundred and twenty-eight consenting patients will be 1:1 randomized to dual-chamber cardiac pacing 'on' or 'off' after pacemaker implantation, and followed up until the first adjudicated primary endpoint event for a maximum of 2 years. The so-called Closed Loop Stimulation function on top of dual-chamber pacing is the pacing mode selected in the study active arm. Participating patients are asked to self-report syncopal symptoms at least every 3 months with self-administered questionnaires addressed to an independent Adjudication Committee. Patients and members of the Adjudicating Committee are blinded to randomization. The study is designed to detect a 40% relative reduction in the 2-year incidence of syncopal recurrences with 80% statistical power. Discussion: The BIOSync study is designed to definitively assess the benefit of pacing against placebo in reflex syncope patients with a cardio-inhibitory response to the TT. The study will also provide important information on the efficiency of the TT in appropriately selecting reflex syncope patients for cardiac pacing.All study-related costs are being directly supported by the sponsor of the study (BIOTRONIK SE & Co. KG, Berlin, Germany). No further funding is provided

    Variance and covariance of actual relationship between relatives at one locus.

    Get PDF
    The relationship between pairs of individuals is an important topic in many areas of population and quantitative genetics. It is usually measured as the proportion of thegenome identical by descent shared by the pair and it can be inferred from pedigree information. But there is a variance in actual relationships as a consequence of Mendelian sampling, whose general formula has not been developed. The goal of this work is to develop this general formula for the one-locus situation,. We provide simple expressions for the variances and covariances of all actual relationships in an arbitrary complex pedigree. The proposed method relies on the use of the nine identity coefficients and the generalized relationship coefficients; formulas have been checked by computer simulation. Finally two examples for a short pedigree of dogs and a long pedigree of sheep are given

    Non-Invasive Detection of Coronary Artery Disease in Patients With Left Bundle Branch Block Using 64-Slice Computed Tomography

    Get PDF
    ObjectivesThe goal of this study was to evaluate the diagnostic accuracy of 64-slice computed tomography (CT) to identify coronary artery disease (CAD) in patients with complete left bundle branch block (LBBB).BackgroundLeft bundle branch block increases risk of cardiac mortality, and prognosis is primarily determined by the underlying coronary disease. Non-invasive stress tests have limited performance, and conventional coronary angiography (CCA) is usually required.MethodsSixty-six consecutive patients with complete LBBB and sinus rhythm admitted for CCA were enrolled. Computed tomography was performed 3 ± 3.9 days before CCA. The accuracy of 64-slice CT to detect significant stenosis (>50% lumen narrowing) was compared with quantitative coronary angiography. All segments were analyzed regardless of image quality from coronary calcification or motion artifacts. Results were analyzed by patient and by coronary segment (990) using the American Heart Association 15-segment model.ResultsLower heart rates were associated with improved image quality. Computed tomography correctly identified 35 of 37 (95%) patients without significant stenosis and 28 of 29 (97%) patients with significant stenosis on CCA. Computed tomography correctly assessed 68 of 94 (72%) significant stenosis. Overall, accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of 64-slice CT for identifying CAD by patient was 95%, 97%, 95%, 93%, and 97%, respectively, and by segment was 97%, 72%, 99%, 91%, and 97%, respectively.ConclusionsIn a routine clinical practice, 64-slice CT detects with excellent accuracy a significant CAD in patients with complete LBBB. A normal CT in this clinical setting is a robust tool to act as a filter and avoid invasive diagnostic procedures

    Excited-state band structure mapping

    Get PDF
    [EN] Angle-resolved photoelectron spectroscopy is an extremely powerful probe of materials to access the occupied electronic structure with energy and momentum resolution. However, it remains blind to those dynamic states above the Fermi level that determine technologically relevant transport properties. In this work we extend band structure mapping into the unoccupied states and across the entire Brillouin zone by using a state-of-the-art high repetition rate, extreme ultraviolet femtosecond light source to probe optically excited samples. The wideranging applicability and power of this approach are demonstrated by measurements on the two-dimensional semiconductor WSe2, where the energy-momentum dispersion of valence and conduction bands are observed in a single experiment. This provides a direct momentum-resolved view, not only on the complete out-of-equilibrium band gap but also on its renormalization induced by electronic screening. Our work establishes a benchmark for measuring the band structure of materials, with direct access to the energy-momentum dispersion of the excited-state spectral function.A This work was funded by the Max-Planck-Gesellschaft, by the German Research Foundation (DFG) , within the Emmy Noether Program (Grant No. RE 3977/1) , and Grants No. FOR1700 (Project E5) , No. SPP2244 (Project No. 443366970) , and from the European Research Council, Grant ERC-2015-CoG-682843. M.P. acknowledges financial support from the Swiss National Science Foundation (SNSF) through Grant No. CRSK-2_196756. C.W.N. and C.M. ac-knowledge financial support by Swiss National Science Foundation (SNSF) Grant No. P00P2_170597. A.R. and H.H. acknowledge financial support from the European Research Council (Grant No. ERC-2015-AdG-694097) and the Cluster of Excellence "CUI: Advanced Imaging of Matter" of the Deutsche Forschungsgemeinschaft (Grant EXC 2056, Project No. 390715994)

    Etude du strabisme chez des enfants de 0 à 15 ans suivis a Lubumbashi, République Démocratique du Congo: analyse des aspects épidémiologiques et cliniques

    Get PDF
    Introduction: Le strabisme est défini comme un syndrome à double composante : motrice et  sensorielle. Le but de ce travail est de décrire les aspects épidémiologiques et cliniques du strabisme chez l'enfant congolais de 0 à 15 ans dans la ville de Lubumbashi.Méthodes: Il s'agit d'une étude descriptive longitudinale sur les aspects épidémiologiques et cliniques du strabisme chez l'enfant congolais de 0 à 15 ans dans la ville de Lubumbashi entre Décembre 2012 à  Décembre 2013. Nous avons recueilli l'âge des patients, leur sexe, leur provenance, le type de strabisme, la réfraction, le fond d'oeil, les antécédents (hérédité) ainsi que le type de la déviation strabique observé sur 70 patients.Résultats: Nous avons observé 70 cas de strabisme manifeste dont 31 cas (44,28%) étaient dans la  tranche d'âge comprise entre 0 et 5 ans. L'âge moyen de nos patients était de 6,7 ans avec une  prédominance du sexe féminin, soit 51,42%. Le strabisme était convergent dans 65,71%, divergent dans 30%, et vertical dans 4,28%. Les ésotropies représentaient 65 cas (92,85%), quatre cas (5,71%)  avaient un antécédent familial de strabisme au premier degré de parenté, 21 cas (30%) au second degré de parenté, 45 cas (64,28%) n'avaient pas cet antécédent. L'oeil gauche était le plus dominé dans 30% des cas. Les facteurs favorisant le strabisme étaient inconnus dans 54 cas (77,14%). Le strabisme était secondaire à l'hypermétropie chez 32 patients (42,71%).Conclusion: La fréquence du strabisme dans la ville de Lubumbashi chez les enfants âgés de 0 à 15 ans  est de 0,50%. Comme dans la plupart des études sur le strabisme de l'enfant, c'est l'ésotropie qui est la  déviation la plus commune.Key words: Enfant congolais, strabisme, hypermétropie, ésotropi

    Landscape-use optimisation with regards to the groundwater resources protection in mountain hardrock areas, LOWRGREP

    No full text
    Synthesis of work performed during the European Project LOWRGREPThis report assesses the degree of interference of human activities with the hydrosphere in mountain-zones, all located in hard-rock areas of different countries in the European Union. Each of the test-regions has a specific degree of protection: from regions with very few inhabitants and very low human impact, to regions submitted to a strong anthropogenic impact. The investigations focused on the changes in water quality and on the simulation of various alternatives leading to optimum landscape-use from the point of view of water-management. The project's own Geographic Information System was used to fulfil the following objective: present all the obtained knowledge and analyse all the data in user-friendly form (maps of water vulnerability) and make this knowledge available for potential users with, for instance, the creation and use of a web site. A simulation tool has been developed which facilitates the assessment of the impact of landscape-use on the water budget of the catchment. In all the areas investigated chloride is present, only in winter and very close to roads. Another result of this work is the decreasing impact on water of sulphur and sulphuric compounds in Germany and in the Czech Republic, while the nitrogen impact is increasing. Recommendations concerning the landscape-use presented for all the regions in particular for good practices in agricultur
    • …
    corecore