Use of organic compounds in molecular electronics

Actualmente, la industria electrónica, basada en el silicio, está llegando a su límite. Así, se están investigando alternativas para poder seguir disminuyendo el tamaño de los chips, a la vez que se aumentan la eficiencia, eficacia y potencia de los mismos. Una de estas alternativas es la electrónica molecular, que al contrario que la industria actual, utiliza el método de abajo-arriba (bottom-up approach), y cuyo objetivo final es el uso de moléculas individuales para fabricar dispositivos electrónicos. Pero antes de convertirse en una realidad, deben superarse muchos retos, como indica la ITRS (International Technology Roadmap for Semiconductors). Algunos de estos retos, que se encuentran directamente relacionados con este TFM, son: (i) conseguir contactos robustos entre los metales y las moléculas orgánicas, (ii) fabricación del electrodo metálico superior (“top-contact”) sobre películas monomoleculares sin dañar el compuesto orgánico, sin penetrar en la película y sin alterar/contaminar las interfaces, y (iii) tener un profundo conocimiento de los mecanismos de transporte de carga a través de los compuestos orgánicos. Considerando estos retos, cuatro compuestos diferentes han sido usados para contribuir en este campo, y concretamente en la fabricación del electrodo superior. Primero, el electrodo superior fue fabricado mediante la ruptura de un compuesto organometálico inmovilizado sobre un sustrato de oro, inducida por calentamiento térmico, y las propiedades eléctricas de estos dispositivos fueron determinadas con un AFM conductor (c-AFM) (capítulo 4). No se han observado cortocircuitos usando este método, por lo que esta estrategia es una técnica alternativa para solucionar los problemas que existen para fabricar el electrodo superior. Segundo, el electrodo superior fue preparado mediante reducción química de una película de grafeno oxidado transferida sobre una monocapa de un compuesto orgánico mediante la técnica de Langmuir-Blodgett (LB) (capítulo 5). Así, estructuras metal | película LB de SOPEA | grafeno reducido (RGO) han sido fabricadas, como han demostrado la espectroscopía UV-Vis, la microbalanza de cuarzo (QCM) y la microscopia de fuerza atómica (AFM)

El poeta y su mundo

Copia digital. Valladolid : Junta de Castilla y León. Consejería de Cultura y Turismo, 2009-201

Pedagogical Reflections on the Context of Teaching and Learning in the Departments of Basic Sciences of Fundación Universitaria del Área Andina

Los procesos de enseñanza y aprendizaje de las ciencias básicas van ligados a la construcción de escenarios de conocimiento contextualizados. De acuerdo con Gibbons y otros autores (1997, citado en González, 2016), la producción de conocimiento se refiere a la forma de acercarse al saber, el cual debe propender por la aplicación de los entornos y la interacción entre ellos y los sujetos. La presente reflexión busca dar cuenta de la experiencia que, como profesores de Física y Matemáticas, se ha tenido en la práctica docente en el Departamento de Ciencias Básicas de la Fundación Universitaria del Área Andina. Se reconocen elementos del hacer didáctico que garantizan aspectos fundamentales en la formación de los estudiantes que pasan por el Departamento en su etapa inicial; en este punto, la función de las ciencias básicas es de vital importancia en la apuesta formativa que posibilita el andamiaje y el recorrido que tendrá un futuro profesional. Reflexionar acerca de qué se enseña lleva a preguntarse por las necesidades actuales de la sociedad desde el aspecto científico, lo que permite vislumbrar la oportunidad de vincular las disciplinas científicas en las actividades cotidianas de los sujetos; por eso, el Departamento de Ciencias Básicas fundamenta su proceso la construcción del conocimiento científico, técnico, tecnológico y cultural. La formación profesional que ofrece el Departamento de Ciencias Básicas se orienta a la resolución de problemas en contextos por medio de los escenarios de la modelación, construir el pensamiento científico como un producto social de acercamiento a las ciencias.Abstract: The teaching and learning processes of the basic sciences are linked to the construction of contextualized knowledge scenarios, according to Gibbons and others (1997) cited by González (2016), the production of knowledge refers to the way of approaching knowledge, which should tend for the application of the environments and the interaction between them and the subjects. The present reflection seeks to account for the experience that as physics and mathematics professors have had in teaching practice in the department of basic sciences of Fundación Universitaria del Área Andina, recognizing elements of didactic work that guarantee fundamental aspects in the formation of Students who pass through the department in their initial training and as future professionals, where the function of basic sciences is of vital importance in the training bet and is the maker of specific constructs that enable scaffolding and the path that a professional future will have . Reflecting on what is taught, leads to asking about the current needs of society from the scientific aspect, which allows to glimpse the opportunity to link the scientific disciplines in the daily activities of the subjects, for this the department of basic sciences bases its process in the construction of scientific, technical, technological and cultural knowledge. For this reason, the professional training offered by the Department of Basic Sciences is oriented to the resolution of problems in contexts through the modeling scenarios, which allow to guide the construction of scientific thought as a social approach product the sciences

Precise positioning of autonomous vehicles combining UWB ranging estimations with on-board sensors

In this paper, we analyze the performance of a positioning system based on the fusion of Ultra-Wideband (UWB) ranging estimates together with odometry and inertial data from the vehicle. For carrying out this data fusion, an Extended Kalman Filter (EKF) has been used. Furthermore, a post-processing algorithm has been designed to remove the Non Line-Of-Sight (NLOS) UWB ranging estimates to further improve the accuracy of the proposed solution. This solution has been tested using both a simulated environment and a real environment. This research work is in the scope of the PRoPART European Project. The different real tests have been performed on the AstaZero proving ground using a Radio Control car (RC car) developed by RISE (Research Institutes of Sweden) as testing platform. Thus, a real time positioning solution has been achieved complying with the accuracy requirements for the PRoPART use case

Stimulated whole salivary flow rate:the most appropriate technique for assessing salivary flow in Sjögren syndrome

We sought to determine the most appropriate method for measuring salivary flow to aid the diagnosis of Sjögren's syndrome (SS). Specifically, we compared the unstimulated whole salivary flow rate (UWSFR) with the stimulated whole salivary flow rate (SWSFR). This case-control study comprised one group of 103 patients with SS and a control group of 50 healthy people. We measured the UWSFR and SWSFR in both groups according to the guidelines established by Navacet (1993). The UWSFR and SWSFR were significantly lower in the patient group compared with the controls (p < 0.01). Among the participants in the patient group, we found a decreased UWSFR in 84 individuals (81.5%) and a decreased SWSFR in 90 individuals (87.4%). We encountered difficulties obtaining saliva in 37 (35.9%) patients during the UWSFR test, and in 12 (11.7%) patients during the SWSFR test. There was no significant statistical difference in the UWSFR or SWSFR between patients with primary and secondary SS. Compared with the UWSFR, the SWSFR is a more suiTable and effective method for measuring salivary flow in patients with SS, as well as for qualitative analysis of the obtained saliva

Consideraciones para una óptima salud en el puesto de trabajo

La ergonomía desempeña un papel creciente en la solución del problema de rehabilitación de personas que en una u otra medida han perdido la capacidad de trabajo; también se estudian las aptitudes y peculiaridades psíquicas y físicas de las personas de edad avanzada y de aquellos individuos considerados como trabajadores especialmente sensibles. Por ello los principios ergonómicos se aplican para optimizar las condiciones de trabajo en relación al bienestar de la persona, su salud y su seguridad, sin olvidar la eficiencia tecnológica y económica. El abordaje de los factores de riesgo que intervienen en la producción de problemas de espalda en los profesionales, incluye al ser humano en sentido integral, desde el punto de vista físico, psicológico y social. En nuestro trabajo nos vamos a centrar en los factores físicos principalmente, destacaremos la adopción de posturas forzadas, movimientos bruscos, así como la inadecuada preparación física y el sedentarismo en una profesión sanitaria, la del técnico en transporte sanitario. Pero no debemos dejar de hacer mención de los otros puntos de vista: el estrés laboral, el apremio de tiempo, que da lugar a que se trabaje con mayor ritmo y no precisamente adoptando posiciones correctas. Aspectos relacionados con la satisfacción laboral también acentúan el estrés y la tensión muscular. La ausencia de una formación preventiva adecuada respecto a técnicas de movilización de enfermos. La falta de personal en los centros de trabajo, que implican una sobrecarga; el deficiente o nulo uso de medios mecánicos adecuadamente diseñados desde el punto de vista ergonómico.Ergonomics plays an increasing role in solving the problem of rehabilitation of people have lost the ability to work, it also examines the skills and mental and physical peculiarities of the elderly and those individuals considered workers are particularly sensitive. Therefore apply ergonomic principles to optimize the conditions of work for the welfare of the person, their health and safety, not forgetting the technological and economic efficiency. The approach of the risk factors involved in the production of back problems in the professionals, including the human being in integral sense from the standpoint of physical, psychological and social. In our work we focus mainly on physical factors, we will highlight the adoption of awkward postures, sudden movements, as well as inadequate physical fitness and physical inactivity in a health profession, the technician in health transport. But we must not fail to mention the other points of view: work stress, time pressure, which leads you to work with greater pace and not just taking proper positions. Aspects related to job satisfaction also accentuate stress and muscle tension. The absence of adequate preventive training on techniques of mobilization of patients. The lack of staff in the workplace, resulting in an overload, the poor or no use of properly designed mechanical means from the ergonomic standpoint.peerReviewe

Supraspinal modulation of neuronal synchronization by nociceptive stimulation induces an enduring reorganization of dorsal horn neuronal connectivity

Despite a profusion of information on the molecular and cellular mechanisms involved in the central sensitization produced by intense nociceptive stimulation, the changes in the patterns of functional connectivity between spinal neurones associated with the development of secondary hyperalgesia and allodynia remain largely unknown. Here we show that the state of central sensitization produced by the intradermal injection of capsaicin is associated with structured transformations in neuronal synchronization that lead to an enduring reorganization of the functional connectivity within a segmentally distributed ensemble of dorsal horn neurones. These changes are transiently reversed by the systemic administration of small doses of lidocaine, a clinically effective procedure to treat neuropathic pain. Lidocaine also reduces the capsaicin-induced facilitation of the spinal responses evoked by weak mechanical stimulation of the skin in the region of secondary but not primary hyperalgesia. The effects of both intradermic capsaicin and systemic lidocaine on the segmental correlation and coherence between ongoing cord dorsum potentials and on the responses evoked by tactile stimulation in the region of secondary hyperalgesia are greatly attenuated in spinalized preparations, showing that supraspinal influences are involved in the reorganization of the nociceptive-induced structured patterns of dorsal horn neuronal connectivity. We conclude that the structured reorganization of the functional connectivity between the dorsal horn neurones induced by capsaicin nociceptive stimulation results from cooperative interactions between supraspinal and spinal networks, a process that may have a relevant role in the shaping of the spinal state in the pathogenesis of chronic pain and analgesia.Peer ReviewedPostprint (author's final draft

Advances in seismic monitoring at Deception Island volcano (Antarctica) since the International Polar Year

Deception Island is an active volcano located in the south Shetland Islands, Antarctica. It constitutes a natural laboratory to test geophysical instruments in extreme conditions, since they have to endure not only the Antarctic climate but also the volcanic environment. Deception is one of the most visited places in Antarctica, both by scientists and tourists, which emphasize the importance of volcano monitoring. Seismic monitoring has been going on since 1986 during austral summer surveys. The recorded data include volcano-tectonic earthquakes, long-period events and volcanic tremor, among others. The level of seismicity ranges from quiet periods to seismic crises (e.g. 1992-1993, 1999). Our group has been involved in volcano monitoring at Deception Island since 1994. Based on this experience, in recent years we have made the most of the opportunities of the International Polar Year 2007-2008 to introduce advances in seismic monitoring along four lines: (1) the improvement of the seismic network installed for seismic monitoring during the summer surveys; (2) the development and improvement of seismic arrays for the detection and characterization of seismo-volcanic signals; (3) the design of automated event recognition tools, to simplify the process of data interpretation; and (4) the deployment of permanent seismic stations. These advances help us to obtain more data of better quality, and therefore to improve our interpretation of the seismo-volcanic activity at Deception Island, which is a crucial step in terms of hazards assessment.This work has been partially supported by the projects POL2006-08663, CGL2007-28855, CTM2008-03062, CTM2009-07705, CTM2009-08085 and CTM2010-11740 of the Spanish Ministry of Science and Innovation

Markovian analysis of the sequential behavior of the spontaneous spinal cord dorsum potentials induced by acute nociceptive stimulation in the anesthetized cat

In a previous study we developed a Machine Learning procedure for the automatic identification and classification of spontaneous cord dorsum potentials (CDPs). This study further supported the proposal that in the anesthetized cat, the spontaneous CDPs recorded from different lumbar spinal segments are generated by a distributed network of dorsal horn neurons with structured (non-random) patterns of functional connectivity and that these configurations can be changed to other non-random and stable configurations after the noceptive stimulation produced by the intradermic injection of capsaicin in the anesthetized cat. Here we present a study showing that the sequence of identified forms of the spontaneous CDPs follows a Markov chain of at least order one. That is, the system has memory in the sense that the spontaneous activation of dorsal horn neuronal ensembles producing the CDPs is not independent of the most recent activity. We used this markovian property to build a procedure to identify portions of signals as belonging to a specific functional state of connectivity among the neuronal networks involved in the generation of the CDPs. We have tested this procedure during acute nociceptive stimulation produced by the intradermic injection of capsaicin in intact as well as spinalized preparations. Altogether, our results indicate that CDP sequences cannot be generated by a renewal stochastic process. Moreover, it is possible to describe some functional features of activity in the cord dorsum by modeling the CDP sequences as generated by a Markov order one stochastic process. Finally, these Markov models make possible to determine the functional state which produced a CDP sequence. The proposed identification procedures appear to be useful for the analysis of the sequential behavior of the ongoing CDPs recorded from different spinal segments in response to a variety of experimental procedures including the changes produced by acute nociceptive stimulation. They are envisaged as a useful tool to examine alterations of the patterns of functional connectivity between dorsal horn neurons under normal and different pathological conditions, an issue of potential clinical concern.Peer ReviewedPostprint (published version