Search results for " física"
showing 10 items of 920 documents
Educación Física: aprendizaje en acción integrando Mobile Learning, Tablets y Apps
2016
Los objetivos del trabajo son: conocer las posibilidades y limitaciones de los dispositivos móviles y las Apps en la enseñanza-aprendizaje de la EF; saber qué instrumentos específicos se pueden utilizar, especialmente durante las clases; conocer las aplicaciones didácticas que tienen tabletas, teléfonos inteligentes y Apps específicas. También, establecer criterios y estrategias para integrar eficazmente los dispositivos móviles en la EF y en las ciencias del deporte
La deducción para madres trabajadoras: un análisis mediante microsimulación
2006
Entre las principales novedades fiscales que ha experimentado el IRPF en los últimos años destaca la deducción por maternidad, que beneficia a las madres con hijos menores de 3 años que trabajan fuera del hogar. Es una medida que pretende fomentar la incorporación de la mujer al mercado de trabajo. En este sentido realizamos una evaluación de algunos impactos fiscales derivados de su introducción. Para ello planteamos un modelo teórico sobre costes y beneficios de la participación en el mercado de trabajo de la mujer casada, análisis que completamos haciendo uso de las técnicas de microsimulación. fuenmayo@uv.es; granell@uv.es higonf@uv.es
Toward the understanding of DNA fluorescence: The singlet excimer of cytosine
2006
By using the multiconfigurational second-order perturbation method CASPT2, including corrections for the basis set superposition error, the lowest-singlet excited state of the face-to-face π-stacked cytosine homodimer is revealed to be bound by about half an eV, being the source of an emissive feature consistent with the observed redshifted fluorescence. Gloria.Olaso@uv.es Daniel.Roca@uv.es Luis.Serrano@uv.es Manuela.Merchan@uv.es
Ionic conduction, rectification, and selectivity in single conical nanopores
2006
Modern track-etching methods allow the preparation of membranes containing a single charged conical nanopore that shows high ionic permselectivity due to the electrical interactions of the surface pore charges with the mobile ions in the aqueous solution. The nanopore has potential applications in electrically assisted single-particle detection, analysis, and separation of biomolecules. We present a detailed theoretical and experimental account of the effects of pore radii and electrolyte concentration on the current-voltage and current-concentration curves. The physical model used is based on the Nernst-Planck and Poisson equations. Since the validity of continuum models for the descriptio…
Hyperpolarized 1H long lived states originating from parahydrogen accessed by rf irradiation
2013
Hyperpolarization has found many applications in Nuclear Magnetic Resonance (NMR) and Magnetic Resonance Imaging (MRI). However, its usage is still limited to the observation of relatively fast processes because of its short lifetimes. This issue can be circumvented by storing the hyperpolarization in a slowly relaxing singlet state. Symmetrical molecules hyperpolarized by Parahydrogen Induced Hyperpolarization (PHIP) provide a straightforward access to hyperpolarized singlet states because the initial parahydrogen singlet state is preserved at almost any magnetic field strength. In these systems, which show a remarkably long 1H singlet state lifetime of several minutes, the conversion of t…
Ion transport and selectivity in nanopores with spatially inhomogeneous fixed charge distributions
2007
Polymeric nanopores with fixed charges show ionic selectivity when immersed in aqueous electrolyte solutions. The understanding of the electrical interaction between these charges and the mobile ions confined in the inside nanopore solution is the key issue in the design of potential applications. The authors have theoretically described the effects that spatially inhomogeneous fixed charge distributions exert on the ionic transport and selectivity properties of the nanopore. A comprehensive set of one-dimensional distributions including the skin, core, cluster, and asymmetric cases are analyzed on the basis of the Nernst-Planck equations. Current-voltage curves, nanopore potentials, and tr…
Accurate Treatment of Large Supramolecular Complexes by Double-Hybrid Density Functionals Coupled with Nonlocal van der Waals Corrections.
2015
In this work, we present a thorough assessment of the performance of some representative double-hybrid density functionals (revPBE0-DH-NL and B2PLYP-NL) as well as their parent hybrid and GGA counterparts, in combination with the most modern version of the nonlocal (NL) van der Waals correction to describe very large weakly interacting molecular systems dominated by noncovalent interactions. Prior to the assessment, an accurate and homogeneous set of reference interaction energies was computed for the supramolecular complexes constituting the L7 and S12L data sets by using the novel, precise, and efficient DLPNO-CCSD(T) method at the complete basis set limit (CBS). The correction of the bas…
Kinesiophobia Levels in Patients with Parkinson’s Disease: A Case-Control Investigation
2021
Background: Kinesiophobia can be an obstacle to physical and motor activity in patients with Parkinson’s disease (PD). PD affects patients’ independence in carrying out daily activities. It also impacts a patient’s biopsychosocial well-being. The objective of this study was to analyze the levels and scores of kinesiophobia in PD patients and compare them with healthy volunteers. Methods: We deployed a case-control study and recruited 124 subjects (mean age 69.18 ± 9.12). PD patients were recruited from a center of excellence for Parkinson’s disease (cases n = 62). Control subjects were recruited from the same hospital (control n = 62). Kinesiophobia total scores and categories were self-rep…
Electronic excited states of conjugated cyclic ketones and thioketones : A theoretical study
2002
Absorption spectra of a series of cyclic conjugated ketones and thioketones have been computed at the multiconfigurational second-order multistate perturbation level of theory, the CASSCF/MS-CASPT2 method. Excitation energies, transition dipole moments, oscillator strengths, and static dipole moments are reported and discussed for excited states with energies lower than ≈ 7–8 eV. The main bands of the spectra have been assigned and characterized in most cases for the first time. The spectroscopy of the different systems is compared in detail. Thioketones in particular have low-energy and intense ππ∗ transitions which suggest corresponding enhanced nonlinear molecular optical properties. Add…
Simple molecular model for the binding of antibiotic molecules to bacterial ion channels
2003
A molecular model aimed at explaining recent experimental data by Nestorovich et al. [Proc. Natl. Acad. Sci. USA 99, 9789 (2002)] on the interaction of ampicillin molecules with the constriction zone in a channel of the general bacterial porin, OmpF (outer membrane protein F), is presented. The model extends T. L. Hill’s theory for intermolecular interactions in a pair of binding sites [J. Am. Chem. Soc. 78, 3330 (1956)] by incorporating two binding ions and two pairs of interacting sites. The results provide new physical insights on the role of the complementary pattern of the charge distributions in the ampicillin molecule and the narrowest part of the channel pore. Charge matching of int…