Understanding quantum emitters in plasmonic nanocavities with conformal transformation: Purcell enhancement and forces.

Nanogaps supporting cavity plasmonic modes with unprecedented small mode volume are attractive platforms for tailoring the properties of light-matter interactions at the nanoscale and revealing new physics. Hitherto, there is a concerning lack of analytical solutions to divide the complex interactions into their different underlying mechanisms to gain a better understanding that can foster enhanced designs. Bowtie apertures are viewed as an effective and appealing nanocavity and are studied here within the analytical frame of conformal transformation. We show how the non-radiative Purcell enhancement of a quantum emitter within the bowtie nanocavity depends strongly not only on the geometry of the nanocavity, but also on the position and orientation of the emitter. For a 20 nm diameter (∅ 20 nm) bowtie nanocavity, we report a change of up to two orders of magnitude in the maximum non-radiative Purcell enhancement and a shift in its peak wavelength from green to infra-red. The changes are tracked down to the overlap between the emitter field and the gap plasmon mode field distribution. This analysis also enables us to understand the self-induced trapping potential of a colloidal quantum dot inside the nanocavity. Since transformations can be cascaded, the technique introduced in this work can also be applied to a wide range of nanocavities found in the literature.

Exploiting the dispersion of the double-negative-index fishnet metamaterial to create a broadband low-profile metallic lens.

Metamaterial lenses with close values of permittivity and permeability usually display low reflection losses at the expense of narrow single frequency operation. Here, a broadband low-profile lens is designed by exploiting the dispersion of a fishnet metamaterial together with the zoning technique. The lens operates in a broadband regime from 54 GHz to 58 GHz, representing a fractional bandwidth ~7%, and outperforms Silicon lenses between 54 and 55.5 GHz. This broadband operation is demonstrated by a systematic analysis comprising Huygens-Fresnel analytical method, full-wave numerical simulations and experimental measurements at millimeter waves. For demonstrative purposes, a detailed study of the lens operation at two frequencies is done for the most important lens parameters (focal length, depth of focus, resolution, radiation diagram). Experimental results demonstrate diffraction-limited ~0.5λ transverse resolution, in agreement with analytical and numerical calculations. In a lens antenna configuration, a directivity as high as 16.6 dBi is achieved. The different focal lengths implemented into a single lens could be potentially used for realizing the front end of a non-mechanical zoom millimeter-wave imaging system.

Three-channel electroencephalogram montage in neonatal seizure detection and quantification.

We compared three-channel montage with 21-channel neonatal minimal placement montage for the detection of neonatal seizures and quantification of seizure burden. Thirty-five neonatal electroencephalograms were retrospectively and blindly reviewed by two independent readers. Tracings were analyzed in the three-channel montage for seizure number, duration, and quantification of seizure burden before reanalysis with the full 21-channel neonatal minimal placement montage. Seizures were identified using standard definitions of electroencephalographic seizure. Sensitivity, specificity, and interrater reliability were calculated. The sensitivity and specificity of three-channel montage for detecting seizures > 10 seconds were 91% and 100% for reader 1, respectively, and 82% and 96% for reader 2, respectively. The interrater agreement for detection of seizures was excellent (κ = 0.86, 94% percent overall agreement). For quantification of seizure burden, strong, positive correlation existed between assessments by full montage and three-channel montage (for reader 1, r = 0.945, n = 11, P < 0.0001; for reader 2, r = 0.902, n = 11, P < 0.0001), and strong correlation existed between the readers for three-channel montage (r = 0.879, n = 11, P < 0.0001). Despite its limitations, three-channel montage is useful in the detection of neonatal seizures and quantification of seizure burden.

Single negative birefringence in stacked spoof plasmon metasurfaces by prism experiment.

We report negative and positive refraction in a prism made of stacked perforated thin surfaces for s and p polarization, respectively. By corrugating the subwavelength slits of a free-standing periodic arrangement, geometrically induced surface-plasmon-like currents are excited and transmission is allowed under s polarization (electric-field vector parallel to the slit). When several of those corrugated slit arrays are subwavelength stacked, the stack behaves as a negative effective index medium (because of double negativity) under s polarization, whereas it behaves as a positive effective index medium under p polarization. The birefringence has been confirmed by the usual wedge experiment in the millimeter-wave range.

Regular and anomalous extraordinary optical transmission at the THz-gap.

In this paper Anomalous Extraordinary Transmission (ET) is reported for s-polarization of low loss doubly periodic subwavelength hole arrays patterned on polypropylene (PP) substrates by conventional contact photolithography at the so-called THz-gap (1-10 THz). The unexpected enhanced transmittance for s-polarization (i.e. without spoof plasmons) was previously numerically demonstrated in subwavelength slits arrays. However, subsequently no experimental work has been devoted to this unexpected Extraordinary Transmission neither in subwavelength slits nor in subwavelength holes. Here, numerical study and experimental results of the Anomalous ET and the symmetric and antisymmetric transmittance modes associated with the already well-known p-polarization ET are shown alongside a systematically analysis of the frequency peaks as a function of hole size for both incident polarizations.

Electroinductive waves role in left-handed stacked complementary split rings resonators.

In this letter it is presented a Left-Handed Metamaterial design route based upon stacked arrays of screens made of complementary split rings resonators under normal incidence in the microwave regime. Computation of the dispersion diagram highlights the possibility to obtain backward waves provided the longitudinal lattice is small enough. The experimental results are in good agreement with the computed ones. The physics underlying the Left-Handed behavior is found to rely on electroinductive waves, playing the mutual capacitive coupling the major role to explain the phenomenon. Our route to Left-Handed metamaterial introduced in this paper based on stacking CSRRs screens can be scaled to millimeter and terahertz for future applications.

Polypropylene-substrate-based SRR- and CSRR- metasurfaces for submillimeter waves.

In this paper it is presented the fabrication of low loss millimeter wave metamaterials based on patterning on polypropylene substrates by conventional contact photolitography. We study numerically and experimentally the transmission and reflection properties of two dimensional arrays of split ring resonators (SRRs), or metasurfaces, and their complementary structure (CSRRs) for co- and cross-polarization excitations up to submillimeter frequencies under normal incidence conditions. The obtained results suggest the possibility of scaling them at terahertz frequencies based on this substrate where other lossy substrates degrade the resonators quality. Left-handed metamaterials derived from these SRRs and CSRRs metasurfaces could be feasible.

Negative refraction in a prism made of stacked subwavelength hole arrays.

Metamaterial structures are artificial materials that show unconventional electromagnetic properties such as negative refraction index, perfect lenses, and invisibility. However, losses are one of the big challenges to be surpassed in order to design practical devices at optical wavelengths. Here we report negative refraction in a prism engineered by stacked sub-wavelength hole arrays. These structures exhibit inherently an extraordinary optical transmission which could offer a solution to the problem of losses at optical wavelengths. It is shown the possibility to obtain negative indices of refraction starting from near to zero values. Our work demonstrates by a direct experiment the feasibility of engineering negative refraction by just drilling sub-wavelength holes in metallic plates and stacking them.

Planoconcave lens by negative refraction of stacked subwavelength hole arrays.

This work presents the design of a planoconcave parabolic negative index metamaterial lens operating at millimeter wavelengths fabricated by using stacked subwavelength hole arrays. A staircase approximation to the ideal parabola profile has been done by removing step by step one lattice in each dimension of the transversal section. Theory predicts power concentration at the focal point of the parabola when the refractive index equals -1. Both simulation and measurement results exhibit an excellent agreement and an asymmetrical focus has been observed. The possibility to design similar planoconcave devices in the terahertz and optical wavelengths could be a reality in the near future.

Afectación articular y muscular secundaria a levofloxacino / Musculoskeletal adverse effects of levofloxacin

No disponible

Tratamiento del dolor en pediatría hospitalaria / Treatment of pain in hospital paediatrics

Fundamento. Se estudia la comorbilidad, observada en la práctica clínica en centros de salud mental públicos, entre los trastornos ocasionados por el uso de alcohol y los ocasionados por el juego de azar. Material y métodos. Se ha estudiado una muestra de 132 pacientes de los que presentaban el diagnóstico "Síndrome de dependencia del alcohol", en tratamiento en los centros de salud mental de la Comunidad de Navarra. Una vez comprobado el diagnóstico de Síndrome de Dependencia del Alcohol se administró el "Cuestionario de juego patológico de South Oaks" en su versión validada en castellano. Resultados. El 23,5 por ciento de los pacientes estudiados, con dependencia de alcohol comprobada, presentaron puntuaciones dentro del rango indicativo de "Probable jugador problema" (5,3 por ciento) y "Probable jugador patológico" (18,2 por ciento). Se confirmó la asociación entre los problemas de juego y el estado civil. Las personas separadas, divorciadas y viudas presentaron más problemas con el juego de azar. Conclusiones. Casi la cuarta parte de los pacientes que presentan "Síndrome de dependencia del alcohol" sufren o han sufrido problemas con los juegos de azar. Es importante tener en cuenta esta realidad, así como la posible presencia de otras asociaciones, en el abordaje del problema de alcohol (desde su prevención, pasando por su evaluación, hasta su tratamiento) (AU)

[Treatment of pain in hospital paediatrics]. / Tratamiento del dolor en pediatría hospitalaria.

The paper presents a review of pain at the paediatric age, which can be considered a question of maximum interest given the novel application of analgesia or other procedures for avoiding and controlling the different types of pain in the course of normal practice during childhood. After a brief introduction on the history of pain and the scarce attention that it has received until recently, the concepts and different actions for dealing with pain are set out, which depend on its aetiology and localisation: pain in oncology, post-operational pain, pain in chronic or acute diseases, pain in intensive care, etc. Tables are presented with the normal doses used at these ages in the different situations required by the child and which the professional might find himself facing. The non-pharmacological attitude is set out as this can be of great use in the initial stages of controlling pain at these ages, and the different forms of sedation and analgesia at the paediatric age are explained, with regard to the medicines employed, the form of administering them and the importance of a multidisciplinary team: paediatricians, child anaesthetists, nursing personnel as well as the necessary technical support for taking the corresponding action.

Prospective application of risk scores in the interhospital transport of patients.

We carried out a prospective evaluation of 172 patients using our own risk score for patients transferred from the emergency department of a community hospital in Tudela, Spain, to main centres, during 1988. Although the data go back almost 10 years, this scoring has not been internationally published and is at present widely applied in Spain. Patients scoring less than 7 points were transferred under specialized nursing supervision (Group I), and those scoring equal to or over 7 points were transferred in a specially equipped intensive care unit surface ambulance and supervised by a physician and a nurse (Group II). There were 102 patients in Group I and 70 in Group II. Complications arising during transfer were defined as minor or serious. A low overall incidence of complications was recorded--a total of 29 cases (16.9% of all transfers). The incidence of complications was significantly higher in Group II patients (p < 0.005). One patient from Group II died during transport. All patients from Group II were admitted to the ICUs compared with only 20 (18.6%) from Group I (p < 0.001). Of a total of 23 deaths in hospital, nine were from Group I and 14 from Group II. During the first 24 hours after admission, six patients died from Group II and none from Group I. The application of risk scores has permitted to assign effectively technical and human resources for a safe interhospital transfer of critically ill patients.

[Evaluation of energy metabolism in burn patients: indirect calorimetry predictive equations]. / Evaluación del gasto energético en pacientes quemados: calorimetría indirecta respecto a ecuaciones predictivas.

INTRODUCTION: Knowing the most reliable method for measuring the metabolic energy use (MEU), is of great importance in patients with severe burns. For the calculation of the energetic requirements of large burn patients, several predictive equations (PE's) are used, based on weight, size, age, body surface area (BSA), and burned body surface (BBS). Previous studies note the tendency for over-or underestimating the MEU, depending on whether one or another PE is used, which is why it is considered necessary to calculate the energy requirements in the most exact manner possible, which can be done by means of indirect calorimetry (IC). MATERIAL AND METHODS: 18 patients (14 men and 4 women) who were admitted to the Burn Unit between 1994 and 1995, were included in the study, with the following inclusion criteria; age > 18 years and < 65 years, and who presented deep burns on are than 15% of the body surface. The MEU of the patients was evaluated by means of IC, using a Deltatrac il unit. The MEU calculated by means of IC was compared with that calculated by means of the four most commonly used PE's in literature: Long Formula: MEU = Basal energy use (BEU) x activity factor x aggression factor which is variable according to the BBS; Curreri Formula: MEU = (Weight x 25) + (total BBS x 40); MEU = 2000 x BSA. As statistical methods, one looked for the existence of correlation, by means of the Pearson method, and the "r" were compared by means of the Fischer conversion. The regression coefficient was found among the values obtained through the PE's and those measured by IC, as well as among those of IC and the percentage of deep burn and the total burned body surface. RESULTS: All the formulate included overestimated the MEU measured between 30.6% and 43.8% with the 2 x MEU formula being the one which did so least (30.6%). In any of them, there is an important variation of the percentage of overestimation with respect to the average MEU in this group. All are correlated in an important way with the MEU. The reliability of these PE's is variable, as is shown by the slopes of the regression lines, with the most reliable PE being that of 2000 x BSA, and that of 2 x MEU, by Harris-Benedict. There is also correlation between the average MEU by IC and the deeply burned body surface. CONCLUSION: This study proves the usefulness of the IC for knowing the EME in burn patients, to prevent their hypernutrition, as well as the relative value of the formulae usually used clinically to estimate this parameter.