Hexacoordinated Oligosilanes from a Hexacoordinated Silicon(IV) Complex Containing an O,N,N,O Salen-type and Thiocyanato-N Ligands

8 páginas, 4 figuras, 3 esquemas, 1 tabla.Two new neutral hexacoordinated silicon complexes with SiN4O2 (6) and SiN3O2C (7) coordinating frameworks were synthesized by reaction of the O,N,N,O-donor salen-type ligand 1,2-bis[[(2-hydroxy-4-methoxyphenyl)(phenyl)methylene]amino]ethane (H2salen*) with Si(NCS)4 and HMeSi(NCS)2, respectively. The complexes 6 [Si(salen*)(NCS)2] and 7 [Si(salen*)Me(NCS)] were studied in the solid-state by 29Si and 15N CP/MAS NMR and in solution by 1H, 13C, and 29Si insensitive nuclei enhanced by polarization transfer (INEPT) NMR, UV/vis and FT-IR spectroscopy. Elemental analysis and single-crystal X-ray diffraction analysis were used to confirm the composition and structure for compounds 6 and 7. Both complexes contain the dianionic salen-type ligand coordinated in an equatorial fashion to the silicon center, while the axial positions are occupied by two thiocyanato-N ligands for 6 and one thiocyanato-N and one methyl ligand for 7. Complex 6, which contains two Si−NCS functional groups, was used as monomer to produce a mixture of linear oligosilanes with a hexacoordinated silicon backbone (formulated SCN-[Si(salen*)]n-NCS, n = 2−8) 8, via a Wurtz-type coupling reaction. Oligomers 8 were identified by solid-state 29Si cross polarization-magic angle spinning NMR and solution 1H and 29Si NMR spectroscopy, matrix assisted laser desorption ionization-time of flight (MALDI-TOF), gel-permeation chromatography (GPC), FT-IR, UV/vis spectroscopy and thermogravimetric analysis (TGA). Conclusive evidence of the oligomeric nature of 8 was provided by MALDI-TOF spectrometry and was supported by quantitative solution 29Si NMR and GPC studies.Financial support for this work was provided by the Mexican Department of Public Education (PROMEP-SEP). G.G.G. thanks the Mexican National Council for Science and Technology (Conacyt) for a PhD scholarship.Peer reviewe

Manejo odontológico del paciente infantil con diferentes grados de afectación pulpar: a propósito de dos casos

El propósito de este Trabajo de Fin de Grado es aplicar los conocimientos teóricos y prácticos adquiridos durante el Grado de Odontología, presentando el manejo de dos casos clínicos odontopediátricos que acuden al Servicio de Prácticas Odontológicas de la Universidad de Zaragoza. Dichos casos, presentan un cuadro clínico de policaries con diferentes grados de afectación pulpar. Ambos estarán documentados de forma detallada, recopilando anamnesis, datos obtenidos de la exploración extraoral e intraoral y pruebas complementarias con el fin de elaborar un diagnóstico y pronostico adecuado, así́ como un plan de tratamiento de manera individualizada. Otro de los propósitos de este trabajo, es la discusión entre diferentes opciones terapéuticas aplicables a los casos expuestos, apoyándonos en la literatura actual. Con la premisa de basarnos en la bibliografía más actualizada, se discutirán y contrastarán los hallazgos clínicos encontrados para elegir el tratamiento más idóneo en base al grado de afectación pulpar diagnosticado y las necesidades unipersonales de cada paciente.<br /

Perfil de la investigación académica sobre Juegos Masivos en Línea para Múltiples Jugadores (JMLMJ) 2000-2009: Horizontes para la investigación educativa

DOI: http://dx.doi.org/10.17227/01234870.38folios75.94Whilst there exists a large body of publications around Massively Multiplayer On-line Role-Play Gaming (MMORPG), there is little profiling academic research on this type of game. This study aims at unveiling what, when, where and who constitute scholarly work in research about MMORPG. A 777-register dataset was configured with primary documents taken from 16 databases and two web-portals. The dataset was drilled down using specialized text-mining software. Findings revealed four main research interests that comprise the games themselves, gaming experiences, systems architecture and educational MMORPG. It was also found that research on this topic started out in 2002 and some milestones of emerging research were charted out. The most prolific organizations and authors were also identified in which the USA, Canada and Italy occupy outstanding places. It is recommended that research profiling studies be carried out to extendmore informed literature reviews and support further research questions.La investigación sobre Juegos Masivos en Línea para Múltiples Jugadores (JMLMJ) es amplia; sin embargo, no hay mucha literatura especializada que perfile la investigación sobre este tipo específico de juegos. El presente estudio persigue describir el qué, el cuándo, el dónde y el quién que constituyen trabajo investigativo y académico sobre los JMLMJ. Se configuró una base de datos de 777 registros con documentos de investigación provenientes de 16 bases de datos académicas y dos portales web. La base de datos que se organizó fue explorada utilizando un software especializado en minería de textos. Los resultados revelan cuatro tendencias principales en la investigación sobre los JMLMJ: los juegos en sí mismos, las experiencias de juego, los sistemas de arquitectura de estos juegos y los JMLMJ relacionados con el fenómeno educativo. Se encontró que la investigación sobre estos juegos se origina en 2002 y se encontraron rutas de investigación relacionadas como desarrollo del campo. Se identificaron los autores más prolíficos quienes son provenientes de organizaciones en USA, Canadá e Italia. Se recomienda la realización de estudios de perfil para ampliar las revisiones de literatura que sustente la formulación de preguntas de investigación

Comportamiento de la queilitis actínica en 30 pacientes. Behavior of actinic cheilitis in 30 patients

Se realizó un estudio prospectivo de 30 pacientes en el Hospital General Universitario "Abel Santamaría Cuadrado" de Pinar del Río en los años 1999 y 2000, cuyo diagnóstico presuntivo era queilitis actínica con predominio en hombres blancos de mediana edad de procedencia rural que trabajan en el campo. El cuadro clínico más frecuente fue ardor, quemazón, eritemas, grietas, sangramientos y ulceraciones. Se realizaron estudios microbiológicos cuyos gérmenes resultantes en los cultivos positivos fueron cándida albicans y estafilococos coagulasa. El tratamiento impuesto fue médico quirúrgico. Se realizó biopsia excisional en 12 pacientes corroborándose el diagnóstico de queilitis en 11 y uno resultó ser un carcinoma escamoso. DeCS: QUEILITIS/ diagnóstico. ABSTRACT A prospective study in 30 patients was carried out between 1999-2000 at Abel Santamaría Cuadrado General Hospital, Pinar del Río. The presumptive diagnosis was actinic cheilitis prevailing in middle age white men that work as farmers. The most frequent clinical findings were burning, erythemas, chaps, bleeding and ulceration. Microbiological studies showed positives cultures resulting in Candida albicans and Staphylococcus coagulase. Surgical management was the elected treatment. The excisional biopsy was performed in 12 patients, being proved the cheilitis diagnosis in 11 patients and squamous cell carcinoma in 1 patient. DeCS: CHEILITIS/diagnosi

Second Metatarsophalangeal joint Synovitis: Update

En las consultas de podología es común la existencia de numerosos procesos patológicos que desarrollan episodios inflamatorios en la cápsula articular de las articulaciones metatarsofalángicas (AMTF) y de sus estructuras vecinas como el plato glenoideo o los ligamentos colaterales, pero no son reconocidas claramente. Diferentes autores lo han explicado como el compromiso articular generado por un proceso de inestabilidad de etiología diversa y que evoluciona en diferentes estadíos, cada uno de los cuales posee diferentes grados de afectación a nivel de esa articulación. Esta patología se localiza en la articulación metatarsofalángica del segundo dedo con mayor prevalencia sobre el tercero en la mayoría de los casos de la bibliografía consultada, siendo reconocida como una de las causas potenciales de metatarsalgias. Los procesos biomecánicos anómalos que sobrecargan las estructuras de antepie pueden provocar una inflamación de la cápsula sinovial que delimita la articulación, disminuyendo progresivamente la movilidad del dedo y agravando la progresión de la patología.In podiatric clinics is very common to find inflamatory process in metatarsophalangeal joint capsule , plantar plate and collateral ligaments damage, but it is not clearly recognized. Many authors hipotetized with joint instability of multiple aetiology and his concomitant evolution in different stages with own joint disease. This pathology has more incidence in second metatarsophalangeal joint than third and others and it is a common etiology of metatarsal pain. Bad biomechanics alters forefoot function and can produce overload in capsular joint, decreasing mobility and getting worse the pathology

Propagation of voltage sags in industrial power networks

The paper analyzes the propagation of voltage sags through the distribution network of an industrial company. For this, power quality is monitoring in high voltage, 44kV, and low voltage, 400V. The theory of M. Bollen is used for the study of the sags recorded by the meters at different points of the installation. It is necessary to know the connection of transformers in order to determine the transmission of the sags.The authors would like to thank the support of the Spanish Government under the research project ENE2007-68032-C04-04/CON

A label-free optical system with a nanohole array biosensor for discriminating live single cancer cells from normal cells

Developing a simple, fast, and label-free method for discrimination between live cancer cells and normal cells in biological samples still remains a challenge. Here, a system is described that fulfills these features to analyze individual living cells. The system consists of a gold nanohole array biosensor plus a microscope optical design to isolate the spectral response of a single cell. It is demonstrated that differences in the spectral behavior between tumor (colorectal cancer cell lines and primary cells from colorectal cancer tissue) and non-tumor cells (peripheral blood mononuclear cells, skin fibroblasts and colon epithelial cells) are influenced by the actin cortex, which lies within the short penetration depth of the surface plasmon electromagnetic field. The efficacy of this system was assessed by the analysis of about one thousand single cells showing the highest discrimination capacity between normal colon epithelial cells and colorectal cancer cells from surgical specimens, with values of sensitivity and specificity ranging 80-100% and 87-100%, respectively. It is also demonstrated that cell discrimination capacity of the system is highly reduced by disrupting the formation of actin cortex. This plasmonic system may find wide applications in biomedicine and to study key cellular processes that involve the actin cortex, including proliferation, differentiation, and migration.This work was supported by the Instituto de Salud Carlos III through grant DTS18/00141, co-funded by European Regional Development Fund/ European Social Fund “A way to make Europe/Investing in your future” and Instituto de Investigación Valdecilla (IDIVAL) (APG/03)

The role of the dc-bus in voltage sags experienced by three-phase adjustable-speed drives

This research work is devoted to the critical evaluation of the role of the dc-bus in the behavior of threephase adjustable-speed drives with voltage sags. In particular, the dc-link voltage variation under voltage sag and its dependence on bus capacity, dc-link resistance and inductance and source impedance. The analysis can be used to introduce additional capacitance in the dc-link in order to increase the ride-through capability of the ASD. Both an electromagnetic transient model and a set-up facility have been introduced. This test platform can be used in order to study the sensitivity of ASD to different disturbances.The authors would like to thank the support of the Spanish Government under the research project ENE2007-68032-C04-04/CON

Participation and relative specialization on regional economic activities in Mexico, 2003-2013

Se utilizaron tres técnicas de análisis regional para determinar el grado de participación y especialización de las actividades económicas en México. Se concluyó que la participación porcentual de las estructuras económicas regionales se modificó, a causa del cambio en la vocación productiva de los territorios

Comparison between IEEE and CIGRE thermal behaviour standards and measured temperature on a 132-kV overhead power line

This paper presents the steady and dynamic thermal balances of an overhead power line proposed by CIGRE (Technical Brochure 601, 2014) and IEEE (Std.738, 2012) standards. The estimated temperatures calculated by the standards are compared with the averaged conductor temperature obtained every 8 min during a year. The conductor is a LA 280 Hawk type, used in a 132-kV overhead line. The steady and dynamic state comparison shows that the number of cases with deviations to conductor temperatures higher than 5 ∘ C decreases from around 20% to 15% when the dynamic analysis is used. As some of the most critical variables are magnitude and direction of the wind speed, ambient temperature and solar radiation, their influence on the conductor temperature is studied. Both standards give similar results with slight differences due to the different way to calculate the solar radiation and convection. Considering the wind, both standards provide better results for the estimated conductor temperature as the wind speed increases and the angle with the line is closer to 90 ∘ . In addition, if the theoretical radiation is replaced by that measured with the pyranometer, the number of samples with deviations higher than 5 ∘ C is reduced from around 15% to 5%This work was supported by the Spanish Government under the R+D initiative INNPACTO with reference IPT-2011-1447-920000 and Spanish R+D initiative with reference ENE2013-42720-R. The authors would also like to acknowledge Viesgo for its support