RESUMO
Internet, Dr. Google, las redes sociales y la web social marcan un nuevo paisaje para el entorno sanitario. Un entorno marcado por los hospitales «líquidos» (H2.0) con profesionales sólidos. Los hospitales, los centros de salud y cualquier organismo sanitario se deben al paciente, al usuario, al ciudadano. Tenemos que ser excelentes y transparentes, tenemos que romper las paredes de nuestros edificios y debemos facilitar la formación y la información. Y todo lo anterior se consigue mejorando el camino de la comunicación. Porque la comunicación es compatible con el rigor y la ética científica, y los hospitales del siglo XXI y sus servicios médicos deben dar el salto a la web social, sin miedo y sin pudor, con sus «5C» (ciencia, conciencia, calidad, color y calor) y sus «4H» (hacerlo bien, hacerlo mejor, hacerlo juntos, hacerlo) y con los recursos de la web 2.0 (comunicación, difusión, colaboración y multimedia). Comentamos la experiencia con la web del Servicio de Pediatría del Hospital General Universitario de Alicante, una vez definidos nuestro porqué y para qué, nuestros objetivos, el fondo y la forma. La web nos ha hecho visibles, presentes y útiles a los profesionales sanitarios, al ciudadano (al usuario, al paciente) y a la sociedad más allá de su estructura física, y ha resultado útil como herramienta de información, formación y gestión. Y cuando nos hacemos visibles, siempre mejoramos: es una ley inexorable (AU)
Internet, Dr. Google, social media and social web draw a new environment for the healthcare industry. An environment marked by the «2.0» hospitals with solid professionals. The hospitals, health centers and any health organization is owing to the patient, the user, the citizen. We have to be excellent and transparent professionals, we have to break the walls and we must provide proper training and information. We can achieve all of that by improving the communication. Because communication is compatible with scientific rigor and ethics, XXI century hospitals and medical services should jump to the next level of social web without fear nor shame, but with science, awareness, quality, color and heat. Just do it, and do it the right way and together taking the advantages of the provided resources by the web 2.0, which mainly are communication, dissemination, collaboration and multimedia. In the article, we discuss the experience launching the website of the Department of Pediatrics of the Hospital General Universitario of Alicante, once defined our objectives, our «reason why», content and form. With this web site we became visible to the public and professionals, and useful not only to practitioners health but also to the citizens in general (the user, the patient) and to the society beyond its physical structure, and it has proved to be useful as a tool for providing information, training and management. And by becoming visible, we always improve: it is an inexorable law (AU)
Assuntos
Humanos , Internet , Mídias Sociais , Pediatria/educação , Gestão da Informação/instrumentação , Hospitais Pediátricos/organização & administração , Sistemas de Comunicação no Hospital/organização & administração , Redes de Comunicação de Computadores/organização & administração , Rede SocialRESUMO
We calculate the spin-orbit induced hole spin relaxation between Zeeman sublevels of vertically stacked InAs quantum dots. The widely used Luttinger-Kohn Hamiltonian, which considers coupling of heavy- and light-holes, reveals that hole spin lifetimes (T1) of molecular states significantly exceed those of single quantum dot states. However, this effect can be overcome when cubic Dresselhaus spin-orbit interaction is strong. Misalignment of the dots along the stacking direction is also found to be an important source of spin relaxation.
RESUMO
We propose an implementation of external homogeneous magnetic fields in kâ p Hamiltonians for holes in heterostructures, in which we make use of the minimal coupling prior to introducing the envelope function approximation. Illustrative calculations for holes in InGaAs quantum dot molecules show that the proposed Hamiltonian outperforms the standard Luttinger model (Luttinger 1956 Phys. Rev. 102 1030) describing the experimentally observed magnetic response. The present implementation culminates our previous proposal (Planelles et al 2010 Phys. Rev. B 82 155307).
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What is the optimum way of describing the age-specific fertility pattern by mathematical functions? We propose a parametric fitting model, based on a mixture of Weibull functions, which performs well for countries where the fertility curve shows a non-traditional pattern. We also consider a simplified version of this model with a reduced number of parameters that can be applied to fit fertility curves in countries where the fertility pattern exhibits a classical shape. To test the new model, fertility curves for a range of countries and years are fitted empirically. The results show that both versions of the new model outperform existing procedures in most cases.
Assuntos
Coeficiente de Natalidade/tendências , Modelos Teóricos , Fatores Etários , Algoritmos , Humanos , Irlanda , Espanha , Reino UnidoRESUMO
We show theoretically that the tunnelling between properly designed defects in periodic antidot lattices can be strongly modulated by applied magnetic fields. Further, transport channels made up of linear arrangements of tunnel-coupled defects can accommodate Aharonov-Bohm cages, suggesting a magnetic control of the transport through the system. Evidence supporting an unusual robustness of the caging effect against electron-electron interactions is also provided.
Assuntos
Elétrons , Magnetismo , Modelos Químicos , Pontos Quânticos , SemicondutoresRESUMO
We study the spin purity of the hole ground state in nearly axially symmetric GaN/AlN quantum dots (QDs). To this end, we develop a six-band Burt-Foreman Hamiltonian describing the valence band structure of zinc blende nanostructures with cylindrical symmetry and calculate the effects of eccentricity variationally. We show that the aspect ratio is a key factor for spin purity. In typical QDs with small aspect ratio the ground state is essentially a heavy hole (HH) whose spin purity is even higher than that of InGaAs QDs of similar sizes. When the aspect ratio increases, mixing with light-hole (LH) and split-off (SO) subbands becomes important and, additionally, the ground state becomes sensitive to QD anisotropy, which further enhances the mixing. We finally show that, despite the large GaN hole effective mass, an efficient magnetic modulation is feasible in QDs with aspect ratio ~1, which can be used to modify the ground state symmetry and hence the optical spectrum properties.
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We theoretically study the effect of the dielectric environment on the exciton ground state of CdSe and CdTe/CdSe/CdTe nanorods. We show that insulating environments enhance the exciton recombination rate and blueshift the emission peak by tens of meV. These effects are particularly pronounced for type-II nanorods. In these structures, the dielectric confinement may even modify the spatial distribution of the electron and hole charges. A critical electric field is required to separate electrons from holes, whose value increases with the insulating strength of the surroundings.
Assuntos
Nanotubos/química , Semicondutores , Compostos de Cádmio/química , Impedância Elétrica , Elétrons , Compostos de Selênio/química , Telúrio/químicaRESUMO
Full configuration interaction calculations for two electrons in narrow semiconductor nanorods are carried out employing different orbital basis sets. It is shown that the usual configurations built from single-particle states cannot yield a correct singlet-triplet energetic order regardless of the basis size, as they miss the correlation energy. Mean-field optimized orbitals partially correct this drawback. A new approach is introduced, based on a simple variational procedure, which yields robust results.
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We provide theoretical modeling of the optical spectrum of recently synthesized triangular CdS nanocrystals by means of atomistic tight-binding theory. Both zinc blende and wurtzite structures are considered. Optical properties predicted for triangular prisms are very different from the ones obtained for tetrahedral quantum dots when z-polarized light is employed. In particular, the ground transition is dim for triangular prisms, whereas it is bright and highly intense for tetrahedra. The high sensitivity of the fine optical properties on the quantum dot shape allows us to discriminate between truncated tetrahedra and triangular prisms and also to estimate the thickness of the nanocrystals.
Assuntos
Compostos de Cádmio/química , Modelos Químicos , Nanoestruturas/química , Sulfetos/química , Compostos de Cádmio/síntese química , Cristalização , Tamanho da Partícula , Transição de Fase , Pontos Quânticos , Sensibilidade e Especificidade , Espectrofotometria/métodos , Sulfetos/síntese química , Propriedades de Superfície , Zinco/químicaRESUMO
Several methods have been used to detect and evaluate small-bowel strictures in Crohn's disease. We describe a simple technique for the calibration of strictures using a 2.5-cm medical plastic sphere. This method provides an aseptic, safe, and effective calibration of the entire small bowel.