Induction theorem analysis of resonant nanoparticles: Design of a huygens source nanoparticle laser

© 2014 American Physical Society. We propose an advanced formulation of standard antenna theory for the basic investigation and design of resonant nanoparticles. This methodology is based on transforming the original scattering problem into a radiation configuration by invoking the induction theorem. Then applying basic antenna theory principles, such as the suppression of any reactive power, the properties of the resonances are engineered. This nanoantenna approach has been validated by revisiting a number of well-known multilayered core-shell structures. It provides additional important physical insights into how the core-shell structures operate and it enables combinations of different resonant phenomena associated with them, e.g., plasmonic and high-Ï resonances, in an intuitive manner. Its efficacy is demonstrated by designing a multilayered nanoparticle that achieves lasing with a maximum directivity in the forward direction and a null in the backward direction, i.e., a Huygens source nanoparticle laser

Magnetic dipole super-resonances and their impact on mechanical forces at optical frequencies

Artificial magnetism enables various transformative optical phenomena, including negative refraction, Fano resonances, and unconventional nanoantennas, beamshapers, polarization transformers and perfect absorbers, and enriches the collection of electromagnetic field control mechanisms at optical frequencies. We demonstrate that it is possible to excite a magnetic dipole super-resonance at optical frequencies by coating a silicon nanoparticle with a shell impregnated with active material. The resulting response is several orders of magnitude stronger than that generated by bare silicon nanoparticles and is comparable to electric dipole super-resonances excited in spaser-based nanolasers. Furthermore, this configuration enables an exceptional control over the optical forces exerted on the nanoparticle. It expedites huge pushing or pulling actions, as well as a total suppression of the force in both far-field and near-field scenarios. These effects empower advanced paradigms in electromagnetic manipulation and microscopy. © 2014 Optical Society of America

Near-field electromagnetic trapping through curl-spin forces

Near-field electromagnetic trapping of particles is generally obtained by means of gradient forces. In this paper, we discuss the attractive behavior of curl-spin forces, as well as their potential for near-field electromagnetic trapping and manipulation. It is demonstrated that curl-spin forces enable the trapping of particles operating at their resonant frequency. Such phenomena can be exploited to design more efficient and selective electromagnetic traps, to boost near-field energy exchange systems, and to bring stability to coupled resonant radiators. It also is illustrated how the balance between the gradient, radiation pressure, and curl-spin force components leads to the formation of zero-force rings around their sources, which explicitly demarcate the trapping regions. Analytical and numerical analyses are presented to assess the stability of the trapping mechanism. © 2013 American Physical Society

Electromagnetic force density in electrically and magnetically polarizable media

The force density induced by electromagnetic fields in electrically and magnetically polarizable media is studied analytically. Different formulations of the force density as a function of field-related quantities, including the spatial derivatives of the fields, gradients of the field intensity, phase gradients, electromagnetic power flow (Poynting vector field), and kinetic momentum flow, are introduced. These formulations retain certain symmetries with respect to the force expressions introduced in previous works for an isolated particle but also point out fundamental differences, such as the suppression of recoil forces, negative radiation pressure, and far-field gradient forces. It is shown how these analytical formulations also provide the necessary means to elucidate the sign of the force density in complex media and how they can assist the design of sources to manipulate clouds of particles. The theory is illustrated with numerical examples of an insulated Hertzian dipole immersed in different media, including lossy dielectrics, media with negative permittivity and permeability, and zero-index media. © 2013 American Physical Society

Is Cytisus multiflorus an antiinflamatory plant?

Cytisus multiflorus is a leguminous shrub native from Iberian Peninsula that is distributed in the south-west Mediterranean region. This plant is used in folk medicine and it is claimed to have various health benefits, including anti-inflammatory properties[1]. Yet, the anti-inflammatory usage of C. multiflorus is totally based on the available ethnopharmacological information while no scientific data on this capacity and on molecular targets has been reported for the plant. Hence, the present work aims to clarify the possible anti-inflammatory mechanisms of C. multiflorus. A purified ethanolic extract was prepared and its high antioxidant capacity was confirmed though the DPPH radical scavenging [2] and reducing power [3] assays (EC50 values 13.4±1.0 and 11.4±2.1 μg/mL, respectively). Moreover, anti-inflammatory properties of the C. multiflorus extract were tested on a lipopolysaccharide-stimulated Raw 264.7 macrophages model. In order to accomplish that, nitric oxide (NO) production, scavenging activity and cytotoxicity of the extract were assessed. Furthermore, the effects on two proteins that are potential targets to prevent or treat chronic inflammation, namely cyclooxygenase-2 (COX-2) and inducible NO synthase (iNOS), were estimated by Western Blot analysis. The obtained results showed that C. multiflorus extract was able to significantly inhibit the production of NO for non-toxic concentrations. The treatment of this cell line with 161 µg/mL and 325 µg/mL of the purified extract induced a decrease in the levels of NO of 24% and 32%, respectively. Furthermore, despite no changes on COX-2 levels were observed, iNOS expression was significantly diminished by the treatment with the highest concentration of the extract. Overall, the present results suggest that C. multiflorus actually exerts an anti-inflammatory action which is, at least partially, mediated through the inhibition of iNOS expression

Introducing mobile edge computing capabilities through distributed 5G Cloud Enabled Small Cells

Current trends in broadband mobile networks are addressed towards the placement of different capabilities at the edge of the mobile network in a centralised way. On one hand, the split of the eNB between baseband processing units and remote radio headers makes it possible to process some of the protocols in centralised premises, likely with virtualised resources. On the other hand, mobile edge computing makes use of processing and storage capabilities close to the air interface in order to deploy optimised services with minimum delay. The confluence of both trends is a hot topic in the definition of future 5G networks. The full centralisation of both technologies in cloud data centres imposes stringent requirements to the fronthaul connections in terms of throughput and latency. Therefore, all those cells with limited network access would not be able to offer these types of services. This paper proposes a solution for these cases, based on the placement of processing and storage capabilities close to the remote units, which is especially well suited for the deployment of clusters of small cells. The proposed cloud-enabled small cells include a highly efficient microserver with a limited set of virtualised resources offered to the cluster of small cells. As a result, a light data centre is created and commonly used for deploying centralised eNB and mobile edge computing functionalities. The paper covers the proposed architecture, with special focus on the integration of both aspects, and possible scenarios of application.Peer ReviewedPostprint (author's final draft

Palliative treatment of metastatic bone pain with radiopharmaceuticals: a perspective beyond Strontium-89 and Samarium-153

PurposeThe present review article aims to provide an overview of the available radionuclides for palliative treatment of bone metastases beyond 89Sr and 153Sm. In addition, it aims to review and summarize the clinical outcomes associated with the palliative treatment of bone metastases using different radiopharmaceuticals.Materials and methodsA literature search was conducted on Science Direct and PubMed databases (1990 - 2015). The following search terms were combined in order to obtain relevant results: bone, metastases, palliative, care, therapy, treatment, radiotherapy, review, radiopharmaceutical, phosphorus-32, strontium-89, yttrium-90, tin-117m, samarium-153, holmium-166, thulium-170, lutetium-177, rhenium-186, rhenium-188 and radium-223. Studies were included if they provided information regarding the clinical outcomes.Results and conclusionsA comparative analysis of the measured therapeutic response of different radiopharmaceuticals, based on previously published data, suggests that there is a lack of substantial differences in palliative efficacy among radiopharmaceuticals. However, when the comparative analysis adds factors such as patients life expectancy, radionuclides physical characteristics (e.g. tissue penetration range and half-life) and health economics to guide the rational selection of a radiopharmaceutical for palliative treatment of bone metastases, 177Lu and 188Re-labeled radiopharmaceuticals appear to be the most suitable radiopharmaceuticals for treatment of small and medium/large size bone lesions, respectively

Antioxidant and anti-inflammatory activities of cytisus multiflorus

Cytisus multiflorus(white spanish broom) is a plant used in folk medicine in the Iberian Peninsula, where it is claimed to have various health benefits. However, the usage is totally based on the available ethnopharmacological information, as no scientific data regarding its biological effects has been delivered. In this sense, is the aim of this work to contribute to the scientific knowledge of the antioxidant and anti-inflammatory properties of C. multiflorus. The extract was rich in phenolic compounds mainly chrysin-7-O-glycopyranoside and a dihydroxyflavone isomer of chrysin which accounted for 49.4±7.3 mg/g and 21.8±3.8 mg/g, respectively. The low EC50 values, determined by DPPH and reducing power assays, indicated that the C. multiflorus purified ethanolic extract has a high antioxidant capacity. Moreover, the extract did not cause cytotoxicity against RAW 264.7 macrophages for high concentrations and the treatment of this cell line with purified extract induced a significant decrease in the levels of NO. Overall, the gathered data suggests that C. multiflorus is in fact a good antioxidant and anti-inflammatory plant, as believed by the folk knowledge

Un índice de sustentabilidad para la evaluación integral de los sistemas de gestión del agua y el saneamiento

En este trabajo se presenta un índice para la evaluación de la sustentabilidad de los sistemas de gestión del agua y el saneamiento. El índice, denominado ISAS (Índice de Sustentabilidad del Agua y el Saneamiento) se basa en un marco conceptual que considera que la sustentabilidad se debería ver como una combinación de aspectos territoriales, temporales y personales. Para la construcción del ISAS se seleccionaron un conjunto de indicadores de sustentabilidad que fueron definidos en función del marco conceptual adoptado. El ISAS se utilizó para evaluar la sustentabilidad del sistema de gestión del agua y el saneamiento de la ciudad de Salta, Argentina. Los indicadores fueron calculados con información de revisiones bibliográficas, cuestionarios, visitas, talleres, datos estadísticos, y análisis de muestras de agua y aguas residuales. El método fue lo suficientemente sensible como para detectar variaciones entre diferentes aspectos del sistema estudiado. Fue también relativamente independiente de la cantidad y la calidad de la información disponible. En el caso de Salta, el valor obtenido para el ISAS fue de 51 puntos en una escala de 0 a 100 cuyo umbral de aceptabilidad se estableció en 50 puntos. El cálculo del ISAS permitió identificar una serie de aspectos del sistema que requieren mejoras y optimización. Este índice puede ser una herramienta útil para evaluar y mejorar la sustentabilidad de los sistemas de gestión del agua y el saneamiento en la región.A comprehensive sustainability index for the assessment of water and sanitation management systems (WSMS) is presented. The index was based on a conceptual framework that perceives sustainability as a combination of territorial, temporal, and personal aspects. A set of sustainability indicators was selected in agreement with this framework, and the “Water and Sanitation Sustainability Index” (WASSI) was built. The WASSI was then used to assess the sustainability of the WSMS of the city of Salta, Argentina. Indicators were calculated with information gathered by several means including literature reviews, questionnaires, visits, sampling, and participatory workshops. The index was sensitive to detect variations between different aspects of the local WSMS. It was also relatively independent of the quantity and quality of the information available. In the case of Salta, the value obtained for the index was 51 points in a scale going from 0 to 100 in which the acceptability threshold was set at 50 points. The WASSI could be a useful tool to assess and improve the sustainability of regional water and sanitation management systems.Fil: Seghezzo, Lucas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Salta. Instituto de Investigaciones en Energía no Convencional; Argentina. Universidad Nacional de Salta; ArgentinaFil: Iribarnegaray, Martín Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Salta. Instituto de Investigaciones en Energía no Convencional; Argentina. Universidad Nacional de Salta; ArgentinaFil: Liberal, V. I.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Salta. Instituto de Investigaciones en Energía no Convencional; Argentina. Universidad Nacional de Salta; ArgentinaFil: Copa, F. R.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Salta. Instituto de Investigaciones en Energía no Convencional; Argentina. Universidad Nacional de Salta; ArgentinaFil: Guerra Munizaga, M. S.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Salta. Instituto de Investigaciones en Energía no Convencional; Argentina. Universidad Nacional de Salta; ArgentinaFil: León, H. E.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Salta. Instituto de Investigaciones en Energía no Convencional; Argentina. Universidad Nacional de Salta; ArgentinaFil: Ruíz, C. Y.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Salta. Instituto de Investigaciones en Energía no Convencional; Argentina. Universidad Nacional de Salta; Argentin

Efeito de sais no solo provenientes de rejeitos da dessalinizacao por osmose inversa no semi-arido pernambucano.

Este trabalho foi um levantamento dos efeitos da dejecao de dois sistemas de dessalinizacao por osmose inversa (RO) de agua de pocos, sobre o solo, localizados nas comunidades de Rajada e Uruas, no municipio de Petrolina-PE. Nessas comunidades estudadas, bem como em todas as comunidades do semi-arido brasileiro, os rejeitos da dessalinizacao sao despejados em sistemas de drenagem natural, sem nenhum tratamento, podendo causar danos ao solo e meio ambiente devido aos seus elevados teores de sais