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Hypoplastic left heart syndrome with an intact atrial septum is a poor predictor of outcomes. Prenatal assessment of pulmonary venous Doppler and emergent postnatal cardiac intervention may be associated with better outcomes.
Materials and methods
A retrospective review of all hypoplastic left heart syndrome patients in two centres over a 5-year period was performed. Group 1 included patients with adequate inter-atrial communication. Group 2 included patients with prenatal diagnosis with an intact atrial septum who had immediate transcatheter intervention. Group 3 included patients with intact atrial septum who were not prenatally diagnosed and underwent either delayed intervention or no intervention before stage 1 palliation. Primary outcome was survival up to stage 2 palliation.
The incidence of hypoplastic left heart syndrome with a restrictive atrial communication was 11.2% (n=19 of 170). Overall survival to stage 2 or heart transplantation was 85% and 67% for Groups 1 and 2, respectively (n=129/151, n=8/12; p=0.03), and 0% (n=0/7) for Group 3. Survival benefits were observed between Groups 2 and 3 (p<0.001). Foetal pulmonary vein Doppler reverse/forward velocity time integral ratio of ⩾18% (sensitivity, 0.99, 95% CI, 0.58–1; specificity, 0.99, 95% CI, 0.96–1) was predictive of the need for emergent left atrial decompression.
Using a multidisciplinary approach and foetal pulmonary vein Doppler, time-saving measures can be instituted by delivering prenatally diagnosed neonates with hypoplastic left heart syndrome with intact atrial septum close to the cardiac catheterisation suite where left atrial decompression can be performed quickly and safely that may improve survival.
We study compact Riemann surfaces of genus $g\geq2$ having a dihedral group of automorphisms. We find necessary and sufficient conditions on the signature of a Fuchsian group for it to admit a surface kernel epimorphism onto the dihedral group $D_N$. The question of extendability of the action of $D_N$ is considered. We also give an explicit parametrization of the moduli space of Riemann surfaces with maximal dihedral symmetry, showing that it is a one-dimensional complex manifold. Defining equations of all such surfaces and the formulae of their automorphisms are calculated. The locus of this moduli space consisting of those surfaces admitting some real structure is determined.
E. Bujalance, Universidad National de Educación a Distancia, Madrid,A. F. Costa, Universidad National de Educación a Distancia, Madrid,E. Martínez, Universidad National de Educación a Distancia, Madrid
In this paper we study the algebraic structure of the hyperelliptic mapping class group of Klein surfaces, which is closely related to the mapping class group of punctured discs. This group plays an important role in the study of the moduli space of hyperelliptic real algebraic curves. Our main result provides a presentation by generators and relations for the hyperelliptic mapping class group of surfaces of prescribed topological type.
Consider the problem of recovering a probability measure supported by a compact subset U of ℝm when the available measurements concern only some of its Ф-moments (Ф being an ℝk valued continuous function on U). When the true Ф-moment c lies on the boundary of the convex hull of Ф(U), generalizing the results of , we construct a small set Rα,δ(∊) such that any probability measure μ satisfying is almost concentrated on Rα,δ(∊). When Ф is a pointwise T-system (extension of T-systems), the study of the set Rα,δ(∊) leads to the evaluation of the Prokhorov radius of the set .
Photoluminescence from porous silicon can be quenched reversibly by a variety of molecular species. Quenching pathways for chemically incorporated surface species, physisorbed species (that undergo no net chemical transformation), and for electron donating reagents have all been identified. For systems involving charge transfer quenching, the concentration dependence typically follows a Stern-Volmer type of relationship, with the more easily oxidized molecules producing the largest Stern-Volmer slopes (most efficient quenching). The slope of the Stern-Volmer plot is dependent upon the particular wavelength that the Stern-Volmer data are obtained from. Data interpretation is complicated by the fact that porous Si shows a wavelength dependent emission lifetime, although when this is taken into account the data can be qualitatively described within the context of a driving-force dependent quenching model. A simple model for understanding the various photoluminescence quenching phenomena observed with porous Si is presented, involving an ensemble of emissive states with energy dependent lifetimes and Stern-Volmer quenching behavior. The model adequately accounts for both red and blue spectral shifts that have been observed upon photoluminescence quenching.