Adherence assessment in patients with venous leg ulcer treated with Unna Boot

RESUMEN: Introducción: Las úlceras de etiología venosa constituyen la lesión más prevalente entre las úlceras de miembro inferior. Son heridas complejas, cuya larga evolución en la cicatrización, y frecuente recidiva las convierten en un reto asistencial. La conducta no-adherente al tratamiento de referencia -terapia compresiva- ha sido objetivada como el principal obstáculo para la cicatrización de las mismas, lo que incrementa la dificultad en su abordaje. Objetivos: Evaluar el impacto de la aplicación de la Bota Unna en la adherencia al tratamiento por parte de los pacientes con úlcera de etiología venosa en comparación con terapias de tratamiento convencional. Metodología: Ensayo clínico aleatorizado y multicéntrico, de diseño factorial 2x2 que se llevará a cabo en los Centros de Atención Primaria del área de Tortosa (Baix Ebre). Participarán 132 pacientes diagnosticados de Úlcera de Etiología Venosa, aleatorizados en 4 grupos de intervención (1:1:1:1), que recibirán tratamiento con (1) vendaje compresivo multicomponente, (2) Bota Unna, (3) la combinación de los dos anteriores y (4) práctica clínica habitual. Se registrará la adherencia terapéutica, la cicatrización de las lesiones, la sintomatología pruriginosa y la calidad de vida de los pacientes durante un período de 12 semanas. El cegamiento se garantizará para el evaluador principal. Plan de Trabajo: Se formará a las enfermeras colaboradoras en el estudio en el abordaje de heridas bajo las directrices de Preparación del Lecho de la Herida, así como en el manejo y aplicación de los distintos sistemas de compresión. Las enfermeras llevarán a cabo el proceso de reclutamiento e intervención en los 15 centros de atención primaria y consultorios del área básica de salud. El análisis de datos será realizado por la investigadora principal, así como la generación de un informe de resultados que se adaptará, en última instancia a un formato para su divulgación.ABSTRACT: Backround: Venous leg ulcer’s are the most prevalent wounds among leg ulcer’s. Venous leg ulcer’s are complex wounds which take long time to heal and often relapse, becoming a healthcare challenge. Non-adherent behaviour has been highlighted as the main issue for the healing process, which increases the difficulty in their management. Objectives: To assess the result on patient’s adherence on treating venous leg ulcers with Unna Boot compressive bandage in comparison with conventional forms of treatment. Method: A randomized controlled trial of 2x2 factorial design will be conducted in the Tortosa area Primary Health Care centres. A total of 132 patients diagnosed with venous leg ulcer will be randomized in 4 interventions groups (1:1:1:1). The treatment groups will be applied (1) multilayer compression bandage, (2) Unna boot, (3) the former two in combination and (4) usual clinical practice. Patient’s adherence and compliance will be measured for 12 weeks period. Likewise, wound healing, pruritus and patient’s quality of life will be also assessed during this period. Work Plan: Collaborator nurses will be given education on wound management under wound bed preparation guidelines, as well as the correct use and application of the different compression bandages for each treatment group. Nurses will perform the recruitment and intervention process among 15 primary health care centres. Data analysis will be conducted by the main researcher, as well as the generation of a results report that will ultimately be adapted to a dissemination format.Grado en Enfermerí

Broadband telecom transparency of semiconductor-coated metal nanowires: more transparent than glass

Metallic nanowires (NW) coated with a high permittivity dielectric are proposed as means to strongly reduce the light scattering of the conducting NW, rendering them transparent at infrared wavelengths of interest in telecommunications. Based on a simple, universal law derived from electrostatics arguments, we find appropriate parameters to reduce the scattering efficiency of hybrid metal-dielectric NW by up to three orders of magnitude as compared with the scattering efficiency of the homogeneous metallic NW. We show that metal@dielectric structures are much more robust against fabrication imperfections than analogous dielectric@metal ones. The bandwidth of the transparent region entirely covers the near IR telecommunications range. Although this effect is optimum at normal incidence and for a given polarization, rigorous theoretical and numerical calculations reveal that transparency is robust against changes in polarization and angle of incidence, and also holds for relatively dense periodic or random arrangements. A wealth of applications based on metal-NWs may benefit from such invisibility

Plasmon spectroscopy: Theoretical and numerical calculations, and optimization techniques

30 págs.; 22 figs.; 1 tab.; Open Access funded by Creative Commons Atribution Licence 3.0We present an overview of recent advances in plasmonics, mainly concerning theoretical and numerical tools required for the rigorous determination of the spectral properties of complex-shape nanoparticles exhibiting strong localized surface plasmon resonances (LSPRs). Both quasistatic approaches and full electrodynamic methods are described, providing a thorough comparison of their numerical implementations. Special attention is paid to surface integral equation formulations, giving examples of their performance in complicated nanoparticle shapes of interest for their LSPR spectra. In this regard, complex (single) nanoparticle configurations (nanocrosses and nanorods) yield a hierarchy of multiple-order LSPR s with evidence of a rich symmetric or asymmetric (Fano-like) LSPR line shapes. In addition, means to address the design of complex geometries to retrieve LSPR spectra are commented on, with special interest in biologically inspired algorithms. Thewealth of LSPRbased applications are discussed in two choice examples, single-nanoparticle surface-enhanced Raman scattering (SERS) and optical heating, and multifrequency nanoantennas for fluorescence and nonlinear optics.J.A.S.-G. and R.P.-D. acknowledge the Spanish >Ministerio de Economía y Competitividad>, through the Consolider-Ingenio project EMET (CSD2008- 00066) and NANOPLAS+ (FIS2012-31070), for financial support.Peer Reviewe

Metallo-dielectric core-shell nanospheres as building blocks for optical three-dimensional isotropic negative-index metamaterials

Materials showing electromagnetic properties that are not attainable in naturally occurring media, so-called metamaterials, have been lately, and still are, among the most active topics in optical and materials physics and engineering. Among these properties, one of the most attractive ones is the subdiffraction resolving capability predicted for media having an index of refraction of -1. Here, we propose a fully three-dimensional, isotropic metamaterial with strong electric and magnetic responses in the optical regime, based on spherical metallo-dielectric core-shell nanospheres. The magnetic response stems from the lowest, magnetic-dipole resonance of the dielectric shell with a high refractive index, and can be tuned to coincide with the plasmon resonance of the metal core, responsible for the electric response. Since the response does not originate from coupling between structures, no particular periodic arrangement needs to be imposed. Moreover, due to the geometry of the constituents, the metamaterial is intrinsically isotropic and polarization independent. It could be realized with current fabrication techniques with materials such as silver (core) and silicon or germanium (shell). For these particular realistic designs, the metamaterials present a negative index in the range of 1.2-1.55οm. © IOP Publishing Ltd and Deutsche Physikalische Gesellschaft.The authors acknowledge support from the Spain Ministerio de Ciencia e Innovacion´ through the Consolider-Ingenio project EMET (CSD2008-00066) and NANOPLAS (FIS2009- 11264) and from the Comunidad de Madrid (grant MICROSERES P2009/TIC-1476). RP-D acknowledges support from CSIC through a JAE-Pre grantPeer Reviewe

Fano-like interference of plasmon resonances at a single rod-shaped nanoantenna

Single metallic nanorods acting as half-wave antennas in the optical range exhibit an asymmetric, multi-resonant scattering spectrum that strongly depends on both their length and dielectric properties. Here we show that such spectral features can be easily understood in terms of Fano-like interference between adjacent plasmon resonances. On the basis of analytical and numerical results for different geometries, we demonstrate that Fano resonances may appear for such single-particle nanoantennas provided that interacting resonances overlap in both spatial and frequency domains.Comment: 18 pages, 9 figure

Resonant metal-semiconductor nanostructures as building blocks of low-loss negative- and zero-index metamaterials

5th International Conference on Metamaterials, Photonic Crystals and Plasmonics; Conferencia invitada.Here we propose a 2D isotropic metamaterial with negative electric and magnetic responses in the optical regime, based on hybrid metallo-dielectric core-shell nanowires. The magnetic response stems from the lowest magnetic resonance of the dielectric shell with high refractive index (i.e., lossless semiconductor), and can be tuned to coincide with the plasmon resonance of the metal core, responsible for the electric response. Also, the same metamaterial design is shown to yield zero refractive index for a different spectral regime (in connection with overlapping resonances), exhibiting in turn an impedance close to that of vacuum.The authors acknowledge financial support from the Spanish “Ministerio de Economía y Competitividad” (CSD2008-00066 and FIS2012-31070), and European Social Fund and CSIC (JAE-Pre and JAE-Doc grants).Peer Reviewe

Localized magnetic plasmons in all-dielectric μ<0 metastructures

6 pags.; 4 figs.; PACS number(s): 41.20.Jb, 42.70.−a, 52.40.Db, 78.67.−n© 2015 American Physical Society. Metamaterials are known to exhibit a variety of electromagnetic properties nonexisting in nature. We show that an all-dielectric (nonmagnetic) system consisting of deep-subwavelength, high-permittivity resonant spheres possesses effective negative magnetic permeability (dielectric permittivity being positive and small). Due to the symmetry of the electromagnetic wave equations in classical electrodynamics, localized >magnetic> plasmon resonances can be excited in a metasphere made of such metamaterial. This is theoretically demonstrated by the coupled-dipole approximation and numerically for real spheres, in full agreement with the exact analytical solution for the scattering process by the same metasphere with effective material properties predicted by effective medium theory. The emergence of this phenomenon as a function of structural order within the metastructures is also studied. Universal conditions enabling effective negative magnetic permeability relate subwavelength sphere permittivity and size with critical filling fraction. Our proposal paves the way towards (all-dielectric) magnetic plasmonics, with a wealth of fascinating applications.This work was supported by the Spanish MINECO (FIS2012- 31070 and FIS2012-36113) and Consolider-Ingenio EMET (CSD2008-00066).Peer Reviewe

Metallo-dielectric core-shell nanospheres as building blocks for optical three-dimensional isotropic negative-index metamaterials

Materials showing electromagnetic properties that are not attainable in naturally occurring media, so-called metamaterials, have been lately, and still are, among the most active topics in optical and materials physics and engineering. Among these properties, one of the most attractive ones is the subdiffraction resolving capability predicted for media having an index of refraction of -1. Here, we propose a fully three-dimensional, isotropic metamaterial with strong electric and magnetic responses in the optical regime, based on spherical metallo-dielectric core-shell nanospheres. The magnetic response stems from the lowest, magnetic-dipole resonance of the dielectric shell with a high refractive index, and can be tuned to coincide with the plasmon resonance of the metal core, responsible for the electric response. Since the response does not originate from coupling between structures, no particular periodic arrangement needs to be imposed. Moreover, due to the geometry of the constituents, the metamaterial is intrinsically isotropic and polarization independent. It could be realized with current fabrication techniques with materials such as silver (core) and silicon or germanium (shell). For these particular realistic designs, the metamaterials present a negative index in the range of 1.2-1.55 μm.Ministerio de Ciencia e Innovación CSD2008-00066, FIS2009- 11264Comunidad de Madrid MICROSERES P2009/TIC-147

Localized magnetic plasmons in all-dielectric \ensuremath{\mu}<0 metastructures

Metamaterials are known to exhibit a variety of electromagnetic properties nonexisting in nature. We show that an all-dielectric (nonmagnetic) system consisting of deep-subwavelength, high-permittivity resonant spheres possesses effective negative magnetic permeability (dielectric permittivity being positive and small). Due to the symmetry of the electromagnetic wave equations in classical electrodynamics, localized “magnetic” plasmon resonances can be excited in a metasphere made of such metamaterial. This is theoretically demonstrated by the coupled-dipole approximation and numerically for real spheres, in full agreement with the exact analytical solution for the scattering process by the same metasphere with effective material properties predicted by effective medium theory. The emergence of this phenomenon as a function of structural order within the metastructures is also studied. Universal conditions enabling effective negative magnetic permeability relate subwavelength sphere permittivity and size with critical filling fraction. Our proposal paves the way towards (all-dielectric) magnetic plasmonics, with a wealth of fascinating applications