Relativistic Runge-Lenz vector: from N=4{\cal N}=4 SYM to SO(4) scalar field theory

Starting from ${\cal N}=4$ SYM and using an appropriate Higgs mechanism we reconsider the construction of a scalar field theory non-minimally coupled to a Coulomb potential with a relativistic SO(4) symmetry and check for scalar field consistency conditions. This scalar field theory can also be obtained from a relativistic particle Lagrangian with a proper implementation of the non-minimal coupling. We provide the generalization of the non-relativistic construction of the Runge-Lenz vector to the relativistic case and show explicitly that this new vector generates the SO(4) algebra. Using the power of the SO(4) symmetry, we calculate the relativistic hydrogen atom spectrum. We provide a generalization of the Kustaanheimo-Stiefel transformation to the relativistic case and relate our results with the corresponding relativistic oscillator. Finally, in the light of these results, we reconsider the calculation of the hydrogen atom spectrum from the cusp anomalous dimension given in [2].Comment: 17 pages. Enhaced version matching the published JHEP version. Typos corrected. The argument of concistence at the end of section 2 was correcte

Present and future of surface-enhanced Raman scattering

The discovery of the enhancement of Raman scattering by molecules adsorbed on nanostructured metal surfaces is a landmark in the history of spectroscopic and analytical techniques. Significant experimental and theoretical effort has been directed toward understanding the surface-enhanced Raman scattering (SERS) effect and demonstrating its potential in various types of ultrasensitive sensing applications in a wide variety of fields. In the 45 years since its discovery, SERS has blossomed into a rich area of research and technology, but additional efforts are still needed before it can be routinely used analytically and in commercial products. In this Review, prominent authors from around the world joined together to summarize the state of the art in understanding and using SERS and to predict what can be expected in the near future in terms of research, applications, and technological development. This Review is dedicated to SERS pioneer and our coauthor, the late Prof. Richard Van Duyne, whom we lost during the preparation of this article

Hybrid Catalysts Comprised of Graphene Modified with Rhodium-Based N-Heterocyclic Carbenes for Alkyne Hydrosilylation

Thermally partially reduced graphene oxide has been covalently modified with 3-methyl-4-phenyl-1, 2, 3-triazolium salts making use of the epoxy functionalities on the carbon nanomaterial. Characterization of the functionalized materials through adequate solid characterization techniques, particularly X-ray photoelectron spectroscopy (XPS), allows one to follow the stepwise building up of the triazolium fragments on the graphene oxide attached to the wall via covalent C-N linkage. The hydroxyl-triazolium-functionalized materials have been used to prepare rhodium hybrid materials containing either alkoxo or triazolylidene molecular rhodium(I) complexes depending on the protection of the hydroxyl groups present in the material. Characterization of the heterogeneous systems, especially by means of XPS and extended X-ray absorption fine structure (EXAFS) spectroscopy, has evidenced the coordination sphere of the supported rhodium(I) complexes in both rhodium hybrid materials. The graphene-oxide-supported rhodium triazolylidene hybrid catalysts show excellent activity, comparable to that of the homogeneous [RhI(cod)(Triaz)] (Triaz = 1, 4-diphenyl-3-methyl-1, 2, 3-triazol-5-ylidene) catalyst, for the hydrosilylation of terminal and internal alkynes. In addition, these catalysts have shown good selectivity to the beta-(Z) vinylsilane isomers (for the not hindered terminal substrates) or syn-additions (for the internal substrates). In contrast to the rhodium(I)-alkoxo-based hybrid material, the silyl-protected rhodium(I)-triazolylidene-based hybrid catalyst can be reused in consecutive cycles without loss of activity maintaining the selectivity. The lack of leaching of active rhodium species demonstrates the strength of the C-N covalent bond of the triazolylidene linker to the graphitic wall

Errores de medicación en niños que acuden a los servicios de urgencias pediátricas

Errores de medicación; Servicios de urgencias; PediatríaMedication errors; Emergency departments; PediatricsErrors de medicació; Servei d'urgències; PediatriaObjectives: Medication safety represents an important challenge in children. There are limited studies on medication errors in pediatric patients visiting emergency departments. To help bridge this gap, we characterized the medication errors detected in these patients, determining their severity, the stages of the medication process in which they occurred, the drugs involved, and the types and causes associated with the errors. Methods: We conducted a multicenter prospective observational study in the pediatric emergency departments of 8 Spanish public hospitals over a 4-month period. Medication errors detected by emergency pediatricians in patients between 0 and 16 years of age were evaluated by a clinical pharmacist and a pediatrician. Each medication error was analyzed according to the updated Spanish Taxonomy of Medication Errors. Results: In 99,797 visits to pediatric emergency departments, 218 (0.2%) medication errors were detected, of which 74 (33.9%) resulted in harm (adverse drug events). Preschoolers were the age group with the most medication errors (126/218). Errors originated mainly in the prescribing stage (66.1%), and also by self-medication (16.5%) and due to wrong administration of the medication by family members (15.6%). Dosing errors (51.4%) and wrong/improper drugs (46.8%) were the most frequent error types. Anti-infective drugs (63.5%) were the most common drugs implicated in medication errors with harm. Underlying causes associated with a higher proportion of medication errors were "medication knowledge deficit" (63.8%), "deviation from procedures/guidelines" (48.6%) and "lack of patient information" (30.3%). Conclusions: Medication errors presented by children attending emergency departments arise from prescriptions, self-medicationand administration, and lead to patient harm in one third of cases. Developing effective interventions based on the types of errors and the underlying causes identified will improve patient safety.Objetivos La seguridad de medicamentos en pediatría supone un verdadero reto. Se dispone de escasos estudios que hayan analizado los errores de medicación en los pacientes pediátricos que acuden a los servicios de urgencias. El objetivo de este estudio ha sido caracterizar los errores detectados en estos pacientes, determinando su severidad, los procesos afectados, los medicamentos implicados, y los tipos de errores y causas asociados. Métodos Estudio multicéntrico observacional prospectivo realizado en los servicios de urgencias de 8 hospitales públicos españoles durante 4 meses. Los errores de medicación detectados por los pediatras de urgencias en pacientes entre 0 y 16 años fueron evaluados por un farmacéutico y un pediatra. Los errores de medicación fueron analizados utilizando la Taxonomía Española de Errores de Medicación actualizada. Resultados En 99.797 visitas a urgencias se detectaron 218 (0,2%) errores de medicación, de los cuales 74 (33,9%) causaron daños (eventos adversos por medicamentos). Los preescolares fueron el grupo poblacional con mayor número de errores de medicación (126/218). Los errores se originaron mayoritariamente en la prescripción (66,1%), por automedicación (16,5%) y por administración equivocada por parte de familiares (15,6%). Los tipos de errores más frecuentes fueron “dosis incorrectas” (51,4%) y “medicamento inapropiado” (46,8%). Los antiinfecciosos (63,5%) fueron los fármacos más comúnmente implicados en los errores con daño. Las causas subyacentes asociadas a una mayor proporción de errores de medicación fueron: “falta de conocimiento del medicamento” (63,8%), “falta de seguimiento de los procedimientos” (48,6%) y “falta de información del paciente” (30,3%). Conclusiones Los errores de medicación en la población pediátrica que acude a urgencias se producen en la prescripción, por automedicación y en la administración, provocando daños a los pacientes en un tercio de las ocasiones. Desarrollar prácticas seguras basadas en los tipos de errores detectados y sus causas subyacentes, mejorará la seguridad de los pacientes.This study has been carried out with the support of a grant provided by the Spanish Society of Hospital Pharmacists for the period 2015–2016

OPTICAL SPECTROSCOPIC OBSERVATIONS OF GAMMA-RAY BLAZAR CANDIDATES. VI. FURTHER OBSERVATIONS FROM TNG, WHT, OAN, SOAR, AND MAGELLAN TELESCOPES

Indexación: Web of ScienceBlazars, one of the most extreme classes of active galaxies, constitute so far the largest known population of.-ray sources, and their number is continuously growing in the Fermi catalogs. However, in the latest release of the Fermi catalog there is still a large fraction of sources that are classified as blazar candidates of uncertain type (BCUs) for which optical spectroscopic observations are necessary to confirm their nature and their associations. In addition, about one-third of the gamma-ray point sources listed in the Third Fermi-LAT Source Catalog (3FGL) are still unassociated and lacking an assigned lower-energy counterpart. Since 2012 we have been carrying out an optical spectroscopic campaign to observe blazar candidates to confirm their nature. In this paper, the sixth of the series, we present optical spectroscopic observations for 30 gamma-ray blazar candidates from different observing programs we carried out with the Telescopio Nazionale Galileo, William Herschel Telescope, Observatorio Astronomico Nacional, Southern Astrophysical Research Telescope, and Magellan. Telescopes. We found that 21 out of 30 sources investigated are BL Lac objects, while the remaining targets are classified as flat-spectrum radio quasars showing the typical broad emission lines of normal quasi-stellar objects. We conclude that our selection of gamma-ray blazar. candidates based on their multifrequency properties continues to be a successful way to discover potential low-energy counterparts of the Fermi. unidentified gamma-ray sources and to confirm the nature of BCUs.http://iopscience.iop.org/article/10.3847/0004-6256/151/4/95/met

Arrhythmia Mechanism and Scaling Effect on the Spectral Properties of Electroanatomical Maps with Manifold Harmonics

[EN] Introduction: Spatial and temporal processing of intracardiac electrograms provides relevant information to support the arrhythmia ablation during electrophysio-logical studies. Current cardiac navigation systems (CNS) and electrocardiographic imaging (ECGI) build detailed 3-D electroanatomical maps (EAM), which represent the spatial anatomical distribution of bioelectrical features, such as activation time or voltage. Objective: We present a principled methodology for spectral analysis of both EAM geometry and bioelectrical feature in CNS or ECGI, including their spectral representation, cutoff frequency, or spatial sampling rate (SSR). Methods: Existing manifold harmonic techniques for spectral mesh analysis are adapted to account for a fourth dimension, corresponding to the EAM bioelectrical feature. Appropriate scaling is required to address different magnitudes and units. Results: With our approach, simulated and real EAM showed strong SSR dependence on both the arrhythmia mechanism and the cardiac anatomical shape. For instance, high frequencies increased significantly the SSR because of the "early-meets-late" in flutter EAM, compared with the sinus rhythm. Besides, higher frequency components were obtained for the left atrium (more complex anatomy) than for the right atrium in sinus rhythm. Conclusion: The proposed manifold harmonics methodology opens the field toward new signal processing tools for principled EAM spatiofeature analysis in CNS and ECGI, and to an improved knowledge on arrhythmia mechanisms.This work was partly supported by Spanish Research Projects TEC2013-48439-C4-1-R, TEC2016-75361-R, and TEC2016-75161-C2-1-4.Sanroman-Junquera, M.; Mora-Jimenez, I.; Garcia-Alberola, A.; Caamano, AJ.; Trénor Gomis, BA.; Rojo-Alvarez, JL. (2018). Arrhythmia Mechanism and Scaling Effect on the Spectral Properties of Electroanatomical Maps with Manifold Harmonics. IEEE Transactions on Biomedical Engineering (Online). 65(4):723-732. https://doi.org/10.1109/TBME.2017.2716189S72373265

Momentos críticos del partido en las mejores ligas europeas de fútbol sala

El presente estudio pretende determinar los momentos críticos donde se consigue el mayor número de goles en la competición de fútbol sala estableciendo diferencias entre las mejores ligas europeas según títulos conseguidos. Material y método: se trata de un estudio cuantitativo, descriptivo y comparativo entre las ligas española, italiana y rusa durante la temporada 2014-2015. La muestra asciende a la totalidad de la población objeto de estudio, que corresponde a 110 partidos en la liga italiana (11 equipos), 240 en la liga española (16 equipos) y 273 en la liga rusa (14 equipos), lo que supone un total de 623 partidos de los que se han podido analizar 619 y una muestra (n) alcanzada de 4716 goles, de los que se han podido analizar 4468. Para el registro de los goles se ha dividido la variable tiempo en intervalos de 5 minutos. Se há utilizado uma estadística descriptiva e inferencial en la búsqueda de relaciones asociativas entre variables categóricas. Resultados: se obtiene que los momentos con más goles del partido son los últimos 10 minutos de la segunda parte y los últimos 5 minutos de la primera parte. Además se determina que las tres mejores ligas europeas se comportan de la misma manera no encontrando diferencias significativas entre ellas. Estos resultados proporcionan información útil sobre las características de los partidos que ayudan a entender mejor la lógica interna de este deporte. The presented research is a quantitative, descriptive and comparative study whose objective is to determine the critical moments of the futsal match by dividing the time variable up to 5 minute intervals, establishing if there are differences between the best European leagues according to titles obtained; Spanish, Italian and Russian league, during the 2014-2015 season. The sample amounts to the entire population under study, corresponding to 110 matches in the Italian league (11 teams), 240 in the Spanish league (16 teams) and 273 in the Russian league (14 teams), which means a total of 623 matches of which 619 have been analyzed and a sample (n) reached of 4716 goals, of which 4468 have been analyzed. The results obtained establish that the moments with the most goals of the game are the last 10 minutes of the second part and the last 5 minutes of the first part. In addition it is determined that the three best European leagues behave in the same way, not finding significant differences between them