2,244 research outputs found
General approach to prepare polymers bearing pendant isocyanate groups
A versatile synthetic approach for the easy preparation, under smooth reaction conditions, of diverse classes of linear polymers bearing aliphatic or aromatic isocyanate groups in the side chains is described. The procedure consists in the transformation of primary amine groups present in the polymer into isocyanates
using equimolar amounts of diphosgene or triphosgene and a soluble tertiary amine as the acid scavenger. The transformation of all amine groups takes place quasi-simultaneously and instantaneously as shown by the invariability of the chain length of the polymer and the absence of crosslinked products. The number of isocyanate groups per molecule that can be achieved by this approach corresponds to the number of primary amine groups of the starting polymer and is up to three orders of magnitude higher than in any other non-crosslinked molecule described so far. The isocyanate functionalized polymers can be used to anchor a large
variety of molecules to the polymer chains. The approach is in detail demonstrated with poly(vinyl chloride) (PVC) carrying aromatic amine groups but has also been confirmed by using a number of other polymer types bearing both aromatic and aliphatic primary amines. Furthermore, it has been used to prepare a novel low molecular weight compound, tris(2-cyanatoethyl)amine.The authors gratefully acknowledge support from Grants MAT2013-42957-R, and RTI2018-096636-J-I0
Non-inverting and Non-isolated Magnetically Coupled Buck-Boost Bidirectional DC-DC Converter
A new non-isolated DC-DC converter with non-inverting output and buck-boost operation, named Magnetically Coupled
Buck-Boost Bidirectional converter (MCB³), is presented in this paper. The MCB³ passive components arrangement connects the input
and output ports getting an equivalent behavior to that of the Dual Active Bridge (DAB) converter, but in a non-isolated topology. This
equivalency allows applying Triple Phase Shift (TPS) modulation to MCB³. TPS is known to minimize conduction losses and to achieve
soft-switching at any load in the DAB converter. Throughout the paper, the features of the DAB converter are used as a reference to show
the main features of the proposed converter. Moreover, other modulation strategies based on TPS modulation are used in MCB³ to
operate within the minimum losses path.The multiple operation modes found on the MCB³ under TPS modulation are identified,
classified, and used to find the operating points that minimize the switching and conduction losses over the power range. The analysis is
shown for the boost mode that is the worst-case design. MCB³ and DAB topologies are designed and simulated for the same specification
to validate the theoretical study. Finally, experimental measurements on 460W-prototypes for both topologies corroborate the equivalent
operation and the main features of the MCB³.This work was supported in part by
the Ministry of Economy and Competitiveness and ERDF funds through the
Research Project “Energy Storage and Management System for Hybrid Electric
Cars based on Fuel Cell, Battery and Supercapacitors” ELECTRICAR-AG-
(DPI2014-53685-C2-1-R), and in part by the Research Projects CONEXPOT
(DPI2017-84572-C2-2-R) and EPIIOT (DPI2017-88062-R
Effect of prevailing winds and land use on Alternaria airborne spore load
[EN] Alternaria spores are a common component of the bioaerosol. Many Alternaria species are plant pathogens, and
their conidia are catalogued as important aeroallergens. Several aerobiological studies showing a strong relationship
between concentrations of airborne spore and meteorological parameters have consequently been
developed. However, the Alternaria airborne load variation has not been thoroughly investigated because it is
difficult to assess their sources, as they are a very common and widely established phytopathogen. The objective
of this study is to estimate the impact of vegetation and land uses as potential sources on airborne spore load and
to know their influence, particularly, in cases of long-medium distance transport. The daily airborne spore
concentration was studied over a 5-year period in Le´on and Valladolid, two localities of Castilla y Le´on (Spain),
with differences in their bioclimatic and land use aspects. Moreover, the land use analysis carried out within a 30
km radius of each monitoring station was combined with air mass data in order to search for potential emission
sources. The results showed a great spatial variation between the two areas, which are relatively close to each
other. The fact that the spore concentrations recorded in Valladolid were higher than those in Le´on was owing to
prevailing winds originating from large areas covered by cereal crops, especially during the harvest period.
However, the prevailing winds in Le´on came from areas dominated by forest and shrubland, which explains the
low airborne spore load, since the main Alternaria sources were the grasslands located next to the trap.
Furthermore, the risk days in this location presented an unusual wind direction. This study reveals the importance
of land cover and wind speed and direction data for establishing potential airborne routes of spore
transport in order to improve the Alternaria forecasting models. The importance of conducting Alternaria aerobiological
studies at a local level is also highlighted.SIThe authors are grateful to the Castilla y Le´on Government’s Health Department for funding the RACYL. This study was partially supported by the AEROHEALTH project [Spanish Ministry of Science and Innovation, Grant PID 2019-106164RB-I00, co-financed with European FEDER funds] and the Junta de Castilla y Le´on, co-financed with European FEDER funds [Grant LE025P20]. A. Rodríguez-Fern´andez acknowledges the Orden EDU/601/2020 grant from the Junta de Castilla y Le´on, co-financed with European FEDER fund
Melomics: A Case-Study of AI in Spain
Traditionally focused on good old-fashioned
AI and robotics, the Spanish AI community
holds a vigorous computational intelligence
substrate. Neuromorphic, evolutionary, or
fuzzylike systems have been developed by many
research groups in the Spanish computer sciences.
It is no surprise, then, that these naturegrounded
efforts start to emerge, enriching the
AI catalogue of research projects and publications
and, eventually, leading to new directions
of basic or applied research. In this article, we
review the contribution of Melomics in computational
creativity.The work on Iamus was partially supported by grants
IPT-300000-2010-010 from the Spanish Ministerio de
Ciencia e Innovación and TSI-090302-2011-8 from
the Spanish Ministerio de Industria, Turismo y Comercio.
The first and fourth authors were supported by
grant P09-TIC-5123 from the Consejería de Innovación
y Ciencia, Junta de Andalucía
Análisis de factibilidad para sistemas de generación de combustibles sólidos a partir de residuos madereros en Colombia
En la actualidad la necesidad de generar cada vez más alternativas para la generación
de energía a partir de recursos renovables que sean más limpios y sostenibles que los
combustibles fósiles, se ha convertido en una actividad mundialmente promovida. Son
muchos los países que han incentivado la generación de sistemas energéticos
basados en el uso de fuentes renovables como la energía solar, eólica o biomasa.
Dentro de esta última están en la actualidad diversos procesos y productos que se
encuentran en desarrollo y aplicación, entre los cuales se encuentran la producción de
biogás a partir de sistemas de digestión anaerobia, la generación de gas de síntesis a
través del proceso de gasificación, obtención de combustibles líquidos como bioetanol
o biodiesel resultantes de procesos de fermentación y transesterificación
respectivamente y la densificación de combustibles sólidos a partir de residuos
madereros.Título de la investigación
Problema de investigación
Objetivos
Objetivo General
Objetivos específicos
Diseño metodológico
Actividades y cronograma
Desarrollo del proyecto
Fase 1
Fase 2
Fase 3
Fase 4
Conclusiones
Referencias y bibliografíaPregradoIngeniero en MecánicaIngeniería Mecánic
Laparoscopic diaphragmatic plication for paralysis posterior to trauma. Case report
Diaphragmatic paralysis is a pathology characterized by the elevation of a plastic and inactive atrophic diaphragm, followed by an injury to the spinal column or to the phrenic nerve. Because it involves the phrenic nerve, it is often associated with an injury at its exit in the spinal cord at the radicular level, at the conduct or in the peripheral nerve. Clinical case: A 50-year-old male patient with a history of thoracic trauma and diagnosis of unstable thorax is admitted for progressive dyspnea in the following 8 months. Diaphragmatic
paralysis is diagnosed and a laparoscopic diaphragmatic plicature is performed. Patient improved his clinical status by 29%. Discussion: The consequences of the elevation of a hemidiaphragm can be respiratory, causing
hypoxemia and decreases in the ventilation---perfusion ratio. This procedure is considered a corrective surgery from the morphological and functional point of view.
Conclusions: Our patient’s clinical status improved according to the Saint George respiratory questionnaire, thanks to an improved perfusion of the basal lung expansion. Laparoscopic diaphragmatic plicature is a safe procedure associated with a minimal hospital stay, and more cases need to be reported. This is the procedure of choice in our institution
Presencia física de profesionales de Salud Mental en un Centro de Atención Primaria como forma alternativa de coordinación. Una experiencia piloto.
Introduccion: problemas de coordinación entre los niveles de atención primaria y salud mental sugieren la necesidad de explorar nuevas vías que faciliten la comunicación entre ambos niveles asistenciales. Material y Método: Un Psiquiatra y un Psicólogo Clínico de Alcalá de Henares (Área 3 de la Comunidad Autónoma de Madrid) se han desplazado un día a la semana a un centro de atención primaria (centro experimental) para evaluar pacientes derivados por los médicos de ese centro y contrastar directamente con ellos sus valoraciones. Después de 15 meses de funcionamiento, se administró a los médicos un cuestionario acerca de su satisfacción con su relación con salud mental. Sus respuestas se compararon con las de médicos de otro centro en el que no tenía lugar la experiencia (centro control). Resultados: los médicos del centro experimental valoraban mejor la información recibida por salud mental y la cantidad de contactos que tenían con ellos, percibían al equipo de salud mental como más disponible, recibían más cursos específicos, se habían coordinado más con salud mental y, en general, valoraban mejor la coordinación atención primaria – salud mental que los del centro control. Conclusiones: La experiencia muestra cómo es posible una forma alternativa de coordinación con la que los médicos de primaria se muestran altamente satisfechos. Se plantean algunas cuestiones metodológicas y posibles vías para continuar futuros trabajos
Ventajas en técnica Nyhus versus Lichtenstein para el tratamiento quirúrgico de la hernia inguinal bilateral
Introduction: Lichtenstein's and Nyhus techniques represent safe hernioplasties; Nyhus is a procedure not yet reported as the choice for bilateral inguinal hernia.Objective: to describe the advantages of Lichtenstein technique comparing Nyhus technique for the management of inguinal hernia as the treatment of choice in patients suffering from bilateral inguinal hernia.Methods: an observational, analytical, and cross-sectional study of control cases was conducted at Abel Santamaría Cuadrado General Teaching Hospital during 2014-2017 in Pinar del Río, Cuba. The sample consisted of 62 cases, in two groups that included 31 patients; Group A: operated by Nyhus technique. Group B: operated in two stages by Lichtenstein technique. Descriptive and inferential statistical tools were applied.Results: in group A, the standard surgical time was 42 minutes, group B was over 60, the chi-square statistician showed the non-homogeneity between the frequencies being statistically significant the difference when observing the value of p=0.00020. The hospitalization time in A averaged 26 hours, in group B predominated more than 48 hours, the statistician chi-square showed the non-homogeneity between the frequencies being statistically significant the difference when observing the value of p=0.00000059. The ratio of complications of group A and B was 1.57. Patients belonging to Group A had no recurrence or inguinodynia symptoms, patients from Group B presented 3 inguinodynia episodes.Conclusions: Nyhus technique is the preferred choice for surgical treatment of bilateral inguinal hernia.Introducción: la técnica de Lichtenstein y Nyhus representan hernioplastias seguras; Nyhus es un proceder que aún no se reporta como elección para la hernia inguinal bilateral.Objetivo: describir las ventajas de la técnica Nyhus en comparación con la técnica de Lichtenstein en el tratamiento de elección en pacientes afectos de hernia inguinal bilateral.Métodos: se realizó un estudio observacional, analítico, y transversal, de casos control, en el Hospital General Docente “Abel Santamaría Cuadrado” Pinar del Río, Cuba, 2014-2017. La muestra quedó constituida por 62 casos, en dos grupos de 31; Grupo A: operados por técnica de Nyhus. Grupo B: operados en dos tiempos por técnica de Lichtenstein. Se aplicaron herramientas de estadística descriptiva e inferencial.Resultados: en el grupo A, la media del tiempo quirúrgico fue 42 minutos, el grupo B resultó por encima de los 60, el estadígrafo Chi-Cuadrado mostró la no homogeneidad entre las frecuencias, al ser una estadística significativa con un valor de p=0,00020. El tiempo de hospitalización en A promedió 26 horas, el grupo B predominó más de 48 horas, el estadígrafo Chi-Cuadrado mostró la no homogeneidad entre las frecuencias al ser la diferencia con un valor de p=0.00000059, una estadística significativa. La razón de complicaciones del grupo A y B fue de 1,57. En los pacientes del grupo A no se presentaron recurrencia ni inguinodinias, en los del grupo B se precisaron tres inguinodinias.Conclusiones: la técnica Nyhus es de elección preferente para el tratamiento quirúrgico de la hernia inguinal bilateral
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