Dyakonov surface waves in lossy metamaterials

We analyze the existence of localized waves in the vicinities of the interface between two dielectrics, provided one of them is uniaxial and lossy. We found two families of surface waves, one of them approaching the well-known Dyakonov surface waves (DSWs). In addition, a new family of wave fields exists which are tightly bound to the interface. Although its appearance is clearly associated with the dissipative character of the anisotropic material, the characteristic propagation length of such surface waves might surpass the working wavelength by nearly two orders of magnitude.

Innovative education networking aimed at multimedia tools for geometrical optics learning

We present a purposeful initiative to open new grounds for teaching Geometrical Optics. It is based on the creation of an innovative education networking involving academic staff from three Spanish universities linked together around Optics. Nowadays, students demand online resources such as innovative multimedia tools for complementing the understanding of their studies. Geometrical Optics relies on basics of light phenomena like reflection and refraction and the use of simple optical elements such as mirrors, prisms, lenses, and fibers. The mathematical treatment is simple and the equations are not too complicated. But from our long time experience in teaching to undergraduate students, we realize that important concepts are missed by these students because they do not work ray tracing as they should do. Moreover, Geometrical Optics laboratory is crucial by providing many short Optics experiments and thus stimulating students interest in the study of such a topic. Multimedia applications help teachers to cover those student demands. In that sense, our educational networking shares and develops online materials based on 1) video-tutorials of laboratory experiences and of ray tracing exercises, 2) different online platforms for student self-examinations and 3) computer assisted geometrical optics exercises. That will result in interesting educational synergies and promote student autonomy for learning Optics.

Subwavelength Bessel beams in wire media

Recent progress is emerging on nondiffracting subwavelength fields propagating in complex plasmonic nanostructures. In this paper, we present a thorough discussion on diffraction-free localized solutions of Maxwell’s equations in a periodic structure composed of nanowires. This self-focusing mechanism differs from others previously reported, which lie on regimes with ultraflat spatial dispersion. By means of the Maxwell–Garnett model, we provide a general analytical expression of the electromagnetic fields that can propagate along the direction of the cylinder’s axis, keeping its transverse waveform unaltered. Numerical simulations based on the finite element method support our analytical approach. In particular, moderate filling fractions of the metallic composite lead to nonresonant-plasmonic spots of light propagating with a size that remains far below the limit of diffraction.

Ultrathin high-index metasurfaces for shaping focused beams

The volume size of a converging wave, which plays a relevant role in image resolution, is governed by the wavelength of the radiation and the numerical aperture (NA) of the wavefront. We designed an ultrathin (λ/8 width) curved metasurface that is able to transform a focused field into a high-NA optical architecture, thus boosting the transverse and (mainly) on-axis resolution. The elements of the metasurface are metal-insulator subwavelength gratings exhibiting extreme anisotropy with ultrahigh index of refraction for TM polarization. Our results can be applied to nanolithography and optical microscopy.

Spectrally tunable light source based on light-emitting diodes for custom lighting solutions

This study describes a novel spectral LED-based tunable light source used for customized lighting solutions, especially for the reconstruction of CIE (Commission Internationale de l’Éclairage) standard illuminants. The light source comprises 31 spectral bands ranging from 400 to 700 nm, an integrating cube and a control board with a 16-bit resolution. A minimization algorithm to calculate the weighting values for each channel was applied to reproduce illuminants with precision. The differences in spectral fitting and colorimetric parameters showed that the reconstructed spectra were comparable to the standard, especially for the D65, D50, A and E illuminants. Accurate results were also obtained for illuminants with narrow peaks such as fluorescents (F2 and F11) and a high-pressure sodium lamp (HP1). In conclusion, the developed spectral LED-based light source and the minimization algorithm are able to reproduce any CIE standard illuminants with a high spectral and colorimetric accuracy able to advance available custom lighting systems useful in the industry and other fields such as museum lighting.

CIMBNC- Combination and interactions of three kinds of nanoclays structural modifiers, for the colored bio-nanocomposites optimization

Biopolymers do not have competitive prices, which has prevented their industrial exploitation on a global scale so far. In this context, Using nanoclays, improvements in certain biopolymer properties, mainly mechanical and thermal, have been achieved. However, research has been much less focused on changing optical properties through the incorporation of nanoclays. At the same time, current research has focused on obtaining nanopigments, by organic dyes adsoptions into different nanoclays in order to achieve sustainable colouring and high performance materials. By combining advances in these lines of research, biodegradable composites with optimal mechanical and optical properties can be obtained. The aim of this work is to find the optimal formulation of naturally sourced nanopigments, incorporate them into a biological origin epoxy resin, and obtain a significant improvement in their mechanical, and optical properties. We combine three structural modifiers in the nanopigment synthesis: surfactant, silane and mordant salt. The latter was selected in order to replicate the mordant textile dyeing with natural dyes. Using a Taguchi’s desing L8, we look for the effect of the presence of the modifiers, the pH acidification, and the interactions effect between the synthesis factors. Three natural dyes were selected: chlorophyll, beta-carotene, and beetroot extract. Furthermore we use two kinds of laminar nanoclays, differentiated by the ion exchange charge: montmorillonite, and hydrotalcite. Then the thermal, mechanical and colorimetric characterization of the bionanocomposite materials was carried out. The optimal conditions to obtain the best bionanocomposite materials are using acid pH, and modifying the nanoclays with mordant and surfactant.

Précis iconographique de médecine opératoire et d'anatomie chirurgicale /

Mode of access: Internet.

Traité pratique d'anatomie médico-chirurgicale /

Mode of access: Internet.

Traité pratique d'anatomie médico-chirurgicale /

Mode of access: Internet.

Traité d'anatomie chirurgicale et de chirurgie expérimentale /

Mode of access: Internet.

Sesamoids of the metatarsophalangeal joint of the big toe: a sistematic review

Abstract: The first metatarsal sesamoid bones are not always taken into consideration when making a diagnosis, in pathologies that affect the region of the first metatarsal head. This is due to the insufficient knowledge of all the pathologies that can affect the sesamoids and the relative little incidence that they have. With the increment of sports activities, in particular the running, increasingly affects of the symptoms concerning this region are observed. Methods: A literature search was performed in 5 databases (Medline, PubMed, Scopus, Cochrane Library and BUCEA). The terms included in the search were: sesamoids, anatomy, biomechanics, sesamoids review and sesamoids pathology. In the initial search articles with no more than 10 years, only humans and revision texts are considered. Results: 24 articles were selected and include different pathologies with diagnosis using imaging tests and treatments, both conservative and surgical; as well as aspects from the biomechanics of the metatarsal-sesamoid joint. Conclusion: Sesamoids due of his anatomy, topography and function can be involved in a lot of pathologies; with similar signs and symptoms that can confuse the podiatry when he has to make a correct diagnosis or treatment.

Vivências dos cuidadores de idosos durante a internação hospitalar

O estudo objetivou conhecer as vivências do cuidador principal no cuidado do idoso no hospital. Realizou-se uma pesquisa descritiva exploratória de cunho qualitativo. Foi executada nas unidades de clínica médica, cirúrgica e serviço de pronto atendimento de um hospital universitário do sul do país, entre os meses de novembro e dezembro de 2013, através de um roteiro de entrevista, respondido por 11 cuidadores de idosos com doenças crônicas. As entrevistas foram transcritas e analisadas com a técnica de análise temática de Minayo. Nesta pesquisa, os cuidadores se caracterizam por ser, na sua maioria, do sexo feminino, casadas, com filhos, sem emprego remunerado e serem filhas do idoso hospitalizado. Os cuidadores participantes entendem a atividade de cuidar como um dever moral, resultado das relações pessoais e familiares. A partir do momento em que necessitam desempenhar tal papel, o assumem como uma exigência decorrente do fato de viverem em família. Os motivos que levaram o cuidador a desempenhar este papel relacionam-se com fatores inerentes ao idoso, como estado de saúde e grau de parentesco. Ao cuidador, fazem alusão ao dever/obrigação, gratidão/retribuição, grau de parentesco, gênero, proximidade afetiva, estado civil, situação atual de emprego e ausência de outra pessoa para realizar o cuidado. Durante o processo de hospitalização do idoso, o cuidador desenvolve ações, tem facilidades e dificuldades e utiliza estratégias que o auxiliam a cuidar. Ao vivenciar o cuidado ao idoso no hospital é influenciado a tornar-se cuidador, apresenta diversas experiências ao cuidar e precisa promover mudanças, em relação ao cuidado, com a internação do idoso. Ao implementar estratégias de cuidado durante a hospitalização do idoso, o familiar cuidador se organiza para cuidar e faz uso de uma rede de apoio para o cuidado. Constatou-se que o idoso e seu cuidador centralizam as necessidades e as decisões, que a rede de apoio informal é a principal provedora de auxílio durante a hospitalização do idoso e que a rede de apoio formal extrahospitalar é existente, porém não apresenta participação ativa no suporte do cuidador familiar. Por outro lado, a equipe de enfermagem responsável pelo cuidado intra-hospitalar foi uma participante ativa na totalidade dos relatos, provendo tanto o cuidado técnico especializado quanto a ajuda nas situações cotidianas emergentes, bem como suporte emocional aos cuidadores e idosos. Outro aspecto relevante destacado foi a falta de ajuda de alguns familiares no amparo aos cuidadores ou até mesmo ao idoso hospitalizado. Esse fato é considerado, pelos cuidadores, uma situação inaceitável, pois a família é vista como o sustentáculo em momentos de crise. As implicações deste estudo nas intervenções da enfermagem no cuidado ao doente e sua família estão relacionadas às discussões e reflexões, a serem realizadas pela equipe de saúde, acerca da inclusão do familiar no espaço hospitalar, pois a sua presença auxilia na manutenção da estabilidade física e emocional do idoso. Desta forma, a enfermagem poderá oferecer apoio ao familiar acompanhante para que se mantenha estável e possa formar uma parceria de cuidados, contribuindo na reabilitação do idoso.

Hallazgos compatibles con material de osteosíntesis en 10.000 radiografías panorámicas: un estudio descriptivo en Bogotá, Colombia

Antecedentes: La radiografía panorámica ha adquirido un gran valor diagnóstico por su bajo costo y detección de hallazgos que no son detectables en la clínica. En cirugía maxilofacial son de utilidad en el seguimiento de procedimientos quirúrgicos mayores ya que permiten visualizar los materiales de osteosíntesis y determinar las patologías óseas con indicaciones quirúrgicas. Objetivo: determinar la prevalencia de material de osteosíntesis en radiografías panorámicas de adultos, buscando su asociación con trauma, anomalía dentofacial, patología quirúrgica y defecto óseo. Método: se valoraron 10.000 radiografías, clasificándolas por sexo, edad y diagnóstico presuntivo. Resultados: se encontraron 173 radiografías con hallazgos de fijación rígida en su mayoría mujeres, entre 21-30 años. Los hombres sufren más trauma mientras que la cirugía ortognática se hace más en mujeres. Conclusión: El material de osteosíntesis se asocia más a corrección de anomalías dentomaxilofaciales en mujeres jóvenes, mientras que la fijación interna rígida asociada a patología quirúrgica es de baja prevalencia

Modelando ciencia: la ceroplástica de Ignacio Lacaba en el Colegio de Cirugía de San Carlos de Madrid

El uso de la ceroplástica como medio de divulgación científica tuvo en la didáctica anatómica del siglo XVIII una enorme difusión. Llegó a trascender las fronteras de una ciencia que impregnaba de conocimiento científico la expresión artística de la belleza a través de la que se manifestaba. Bajo estas premisas se creó en el Real Colegio de Cirugía de San Carlos de Madrid la colección de modelos anatómicos, de la que es custodio el actual Museo de Anatomía Javier Puerta de la Facultad de Medicina de la Universidad Complutense de Madrid. La colección se inició en 1786 con Ignacio Lacaba, primer disector del colegio de cirugía madrileño, cuya sensibilidad artística y profundo conocimiento de la anatomía contribuyó y facilitó la armonización entre la labor de los ceroescultores y el lenguaje y expresión anatómica.

Abordajes endoscópicos a la base de cráneo anterior

Los abordajes endoscópicos a la base de cráneo anterior se han desarrollado de forma muy importante en las últimas décadas y continúan extendiéndose paralelamente a la aparición de nuevo instrumental y equipo que facilitan su aplicación. Factores importantes que han contribuido a ello son la posibilidad de acceder de forma directa a zonas difíciles y la disminución de morbilidad que pueden aportar, manteniendo los resultados esperados. Pero también tienen desventajas y limitaciones pues requieren conocimiento anatómico y el uso de material específico en un campo quirúrgico limitado por el espacio, estructuras anatómicas vitales y la visión bidimensional. La correcta planificación quirúrgica y la selección de los pacientes son elementos fundamentales. Esto nos permitirá determinar si es posible este tipo de abordaje, conocer la localización de la lesión, la zona de entrada al cráneo y el corredor que deberemos utilizar para ello. Los abordajes endoscópicos, correctamente indicados y planificados son procedimientos seguros y efectivos.