2,459 research outputs found

    Colorless devices and reception techniques for polarization multiplexed communications

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    Future optical networks call for flexible, high performance and low cost coherent optical receivers. We present here several advances towards such receivers, including integrated optical couplers with ultra-broad bandwidth, as well as novel reception techniques and architectures that will enable high performance coherent reception without filtering and polarization splitting elements.Universidad de Málaga - Campus de Excelencia Internacional Andalucía Tech. Spanish Ministry of Science under project TEC2013-46917-C2-1-

    Effect of the distribution of anisotropy constants on the magnetic properties of iron oxide nanoparticles

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    The distribution of shape anisotropy constants in two colloids of iron oxide nanoparticles has been measured from the distribution of particle elongations within each system. The results are in good agreement with the values calculated from a temperature decay of remanence measurement. For a fluid with a saturation magnetisation of 420 emu/cc and an average particle elongation of ~1.3, the distribution of energy barriers is controlled by both the distribution of particle sizes and particle elongations. For a fluid with a saturation magnetisation of 320 emu/cc and a wide distribution of particle sizes, the energy barrier to reversal can be assumed to be controlled by the distribution of particle volumes. These results highlight the need to take into account the distribution of anisotropy constants when making predictions of the heating properties of assemblies of magnetic nanoparticles for hyperthermia applications

    Measurement of the distribution of anisotropy constants in magnetic nanoparticles for hyperthermia applications

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    In this work we have applied theoretical calculations to new experimental measurements of the effect of the anisotropy distribution in magnetite nanoparticles which in turn controls hysteresis heating for hyperthermia applications. Good agreement between theory and experiment is reported where the theoretical calculation is based upon the detailed measurement of the particle elongation generally observed in the nanoparticles. The elongation has been measured from studies via transmission electron microscopy (TEM). We find that particle elongation is responsible for the anisotropy dispersion which can be obtained by analysis and fitting to a measurement of the temperature decay of remanence. A median value of the anisotropy constant of 1.5x105erg/cc was obtained. A very wide distribution of anisotropy constants is present with a Gaussian standard deviation of 1.5x105erg/cc. From our measurements, deviations in the value of the saturation magnetisation from particle to particle are most likely the main factor giving rise to this large distribution with 33% arising from the error in the measured elongation. The lower limit to the anisotropy constant of the nanoparticles is determined by the magnetocrystalline anisotropy of the material, 1.1x105erg/cc for magnetite which was studied in this work

    REPORTES CLINICOS: INFECCION RINOSINUSAL PROBADA POR Aspergillus flavus Y PROBABLE INFECCION PULMONAR POR Emericella nidulans EN PACIENTES INMUNODEPRIMIDOS

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    En los ultimos 20 años la incidencia de aspergilosis invasiva ha aumentado  entre 5 y 10 veces, presentando una mortalidad que varía desde un 60 a 98% dependiendo de su localización, enfermedad de base(inmunodepresión), diagnóstico y tratamiento precoz. A pesar que se ha logrado un importante avance en estos dos últimos decenios, aproximadamente un 50% de los casos se diagnostican post mortem. Se reportan dos casos de aspergilosis (probada y probable) en pacientesinmunodeprimidos de 21 y 44 años respectivamente. El primer caso corresponde a una infección rinosinusal en una paciente con leucemia linfoblastica, con un cuadro clínico caracterizado por aumento de volumen facial  izquierdo, compromiso progresivo del estado general yequímosis en región periorbitaria. La endoscopia nasal detectó abundante secreción y tejido friable amarillento sugerente de infección micótica. Las muestras de tejidos enviadas al laboratorio para exámen directo y cultivos arrojaron presencia de hifas en la mucosa y crecimientoabundante de Aspergillus flavus. Se inició terapia con itraconazol, cambiándose posteriormente a voriconazol, con respuesta favorable y disminución del dolor y volumen facial. Sin embargo, la paciente fallece al 10º día del ingreso debido a su mal estado general, avance de la falla medular y posterior insuficiencia respiratoria. El segundo caso corresponde a una probable infección pulmonar en una paciente con cáncer de mama en tratamiento quimioterápico. La paciente ingresó conel diagnóstico de neutropenia febril y probable neumonia de etiología bacteriana, fue tratada con antimicrobianos tanto en el hospital comunal como en el de base. Sin embargo, presentó una evolución tórpida, cursando posteriormente con hemoptisis, insuficiencia respiratoriay compromiso de conciencia. Se tomaron muestras de secreción endotraqueal las que fueron enviadas para estudio bacteriológico(TBC) y micológico, además de hemo y urocultivos. Los resultados de los examenes efectuados fueron negativos, excepto todos los cultivosmicológicos que tempranamente (4 días) detectaron un amplio crecimiento de Aspergillus (Emericella) nidulans. Al momento del informe micológico la paciente había fallecido en el hospital base

    Conventional Cervical Exercises Compared with a Mixed-Reality-Based Game in Asymptomatic Subjects: An Exploratory Crossover Pilot Study.

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    Mixed reality presents itself as a potential technological tool for the management of people with musculoskeletal disorders, without having as many adverse side effects as immersive virtual reality. The objective of this study was to explore the possibilities of a mixed-reality game, performing task-oriented cervical exercises compared to conventional therapeutic exercises in sensorimotor outcome measures in asymptomatic subjects. A randomized crossover pilot study was performed with two intervention groups: a mixed-reality group (MRG) and a conventional exercise group (CEG). The cervical joint position error test (CJPET) and deep cervical flexor endurance test (DCFET) were measured as sensorimotor outcomes. Statistically significant differences were found in the pre–post comparison in the DCFET for both groups (MRG: t = �����3.87, p < 0.01; CEG: t = �����4.01, p < 0.01) and in the extension of the CJPET for the MRG (t = 3.50, p < 0.01). The rest of the measurements showed no significant differences comparing both groups pre- and postintervention (p > 0.05). Mixed reality has apparently the same positive effects as conventional exercises in sensorimotor outcomes in asymptomatic subjects. These results could help in future studies with mixed virtual reality in the management of people with musculoskeletal disorders.post-print882 K

    An Antimethanogenic Nutritional Intervention in Early Life of Ruminants Modifies Ruminal Colonization by Archaea

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    The aim of this work was to study whether feeding a methanogen inhibitor from birth of goat kids and their does has an impact on the archaeal population colonizing the rumen and to what extent the impact persists later in life. Sixteen goats giving birth to two kids were used. Eight does were treated (D+) with bromochloromethane after giving birth and over 2 months. The other 8 goats were not treated (D−). One kid per doe in both groups was treated with bromochloromethane (k+) for 3 months while the other was untreated (k−), resulting in four experimental groups: D+/k+, D+/k−, D−/k+, and D−/k−. Rumen samples were collected from kids at weaning and 1 and 4 months after (3 and 6 months after birth) and from does at the end of the treating period (2 months). Pyrosequencing analyses showed a modified archaeal community composition colonizing the rumen of kids, although such effect did not persist entirely 4 months after; however, some less abundant groups remained different in treated and control animals. The different response on the archaeal community composition observed between offspring and adult goats suggests that the competition occurring in the developing rumen to occupy different niches offer potential for intervention

    Subwavelength gratings for sensing and polarization management

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    Sub-wavelength grating (SWGs) structures are becoming important building blocks in planar waveguide photonic devices [1]. SWG structures have been successfully applied in the design of a range of devices with remarkable performance by using refractive index engineering and dispersion engineering techniques [2]. In this work we explore two new promising applications of these structures, namely in evanescent field waveguide sensing and polarization management. For the evanescent waveguide sensing devices, we show that sub- wavelength patterning of silicon wires can be used to control the delocalization of the waveguide mode and therefore enhance both bulk and surface sensitivities (Fig. 1). We will also discuss the implementation of subwavelength structures in efficient polarization splitter and rotator (PSR) devices [3]. PSR devices based on asymmetrical directional couplers typically exhibit stringent fabrication tolerances. We show that by implementing SWG structures in PSR design both the effective mode index and its derivatives with respect to critical dimensions can be controlled, which significantly improves tolerance to fabrication errors (Fig. 2).Universidad de Málaga, Campus de Excelencia Internacional Andalucía Tech

    Autonomic nervous system assessment in critically ill patients undergoing a cognitive rehabilitation therapy

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    Recent clinical and electrophysiological studies reveal a high incidence of autonomic nervous system (ANS) dysfunction in patients treated in Intensive Care Units (ICUs). Cognitive rehabilitation (CR) is a behavioral therapy that has proven to be effective improving cognitive deficits in clinical populations with abnormalities in brain activation patterns. A total of 17 critically ill patients received CR aimed to improve the ANS status, which was quantified in terms of HRV. The CR included cognitive exercises aimed to improve prefrontal activation. HRV was obtained during pre-CR, CR and post-CR. Power in the low (PLF) and high (PHF) frequency bands related to sympathetic and parasympathetic systems was computed. PHF was obtained within a band centered at respiratory rate. Comparing with baseline values, 7 patients showed an increased PHF in post-CR, suggesting an increase of parasympathetic activity

    Mechanisms of coronavirus pathogenicity and virus-host interactions

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    Trabajo presentado en la Conference on the Cooperation and Collaboration on Prevention and Control of Animal Diseases, celebrada en Hangzhou (China), del 21 al 23 de mayo de 2019Coronaviruses (CoVs) are important human and animal pathogens mainly causing respiratory and enteric infections with diverse severity. The presence of CoVs in bats, as animal reservoirs, and their ability for interspecies transmission have recently led to the emergence of novel CoVs responsible for epidemics in humans and livestock. In order to develop protection strategies against CoV infections, our laboratory is interested in the identification of (i) Viral factors involved in virulence and (ii) Host signaling pathways contributing to pathogenesis, using human coronaviruses SARS- and MERS-CoVs as model systems

    Re-inventing Multimode Interference Couplers Using Subwavelength Gratings

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    We use the concept of subwavelength grating (SWG) refractive-index-engineering to propose and experimentally demonstrate a reduced size, slotted 2x2 MMI coupler. We also present an ultra-broadband 2x2 MMI coupler which is based on SWG dispersion engineering.This work was supported in part by the Spanish Ministerio de Ciencia (project TEC2009-10152), a Formación del Profesorado Universitario scholarship (AP-2006-03355), the European Mirthe project (FP7-2010-257980) and “Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
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