Lesiones de la articulación tarso-metatarsiana

Se presentan 16 casos de fractura-luxación tarso-metatarsiana. El objetivo de este trabajo ha sido la valoración de los resultados finales en este tipo de patología. La etiología del accidente ha sido en 6 ocasiones casual o deportiva, en 5 laboral, en 4 accidente de tráfico y 1 caída de un caballo. Las fractura-luxaciones han sido clasificadas según los criterios de Hardcastle, resultando 3 casos tipo A externo, 6 B externo, 6 B interno y 1 C total. El tratamiento realizado fue mayoritariamente reducción y osteosíntesis con agujas de Kirschner, predominando la reducción abierta. Se ha considerado parámetros radiográficos y clínicos, siguiendo los criterios del Baltimore Painful Foot Store para la valoración de resultados finales, obteniéndose 9 casos excelentes, 4 buenos, 2 reguladores y 1 malo. Se concluye que es fundamental el diagnóstico y tratamiento precoz, considerando básica la reducción anatómica estabilizada con agujas de Kirschner.We report 16 cases of tarsometatarsal fracture-dislocation. The purpose of this work was the assessment of the final outcome of these cases. The etiology was casual or sport injuries in 6 cases, industrial accidents in 5, traffic accidents in 4 and fall off a horse in 1 case. The injuries have been classified according to the Hasrdcastle modified classification, being 3 cases type A external, 6 B internqal and 1 C total. In most cases the treatment was open reduction and internal fixation with Kirschner wires. According to the guidelines of the Balitmore Painful Score for the evaluation of final outcome, there were 9 excellent results, 4 good, 2 fair and 1 poor. We conclude that the best results were obtained in those cases with early diagnose and treatment, looking for an anatomical reduction and fixation with Kirschner wires

Interactive effects of vertical mixing, nutrients and ultraviolet radiation: in situ photosynthetic responses of phytoplankton from high mountain lakes in Southern Europe

Global change, together with human activities, has resulted in increasing amounts of organic material (including nutrients) that water bodies receive. This input further attenuates the penetration of solar radiation, leading to the view that opaque lakes are more "protected" from solar ultraviolet radiation (UVR) than clear ones. Vertical mixing, however, complicates this view as cells are exposed to fluctuating radiation regimes, for which the effects have, in general, been neglected. Furthermore, the combined impacts of mixing, together with those of UVR and nutrient inputs are virtually unknown. In this study, we carried out complex in situ experiments in three high mountain lakes of Spain (Lake Enol in the National Park Picos de Europa, Asturias, and lakes Las Yeguas and La Caldera in the National Park Sierra Nevada, Granada), used as model ecosystems to evaluate the joint impact of these climate change variables. The main goal of this study was to address the question of how short-term pulses of nutrient inputs, together with vertical mixing and increased UVR fluxes modify the photosynthetic responses of phytoplankton. The experimentation consisted in all possible combinations of the following treatments: (a) solar radiation: UVR + PAR (280–700 nm) versus PAR (photosynthetically active radiation) alone (400–700 nm); (b) nutrient addition (phosphorus (P) and nitrogen (N)): ambient versus addition (P to reach to a final concentration of 30 μg P L−1, and N to reach N:P molar ratio of 31); and (c) mixing: mixed (one rotation from surface to 3 m depth (speed of 1 m 4 min−1, total of 10 cycles)) versus static. Our findings suggest that under ambient nutrient conditions there is a synergistic effect between vertical mixing and UVR, increasing phytoplankton photosynthetic inhibition and excretion of organic carbon (EOC) from opaque lakes as compared to algae that received constant mean irradiance within the epilimnion. The opposite occurs in clear lakes where antagonistic effects were determined, with mixing partially counteracting the negative effects of UVR. Nutrient input, mimicking atmospheric pulses from Saharan dust, reversed this effect and clear lakes became more inhibited during mixing, while opaque lakes benefited from the fluctuating irradiance regime. These climate change related scenarios of nutrient input and increased mixing, would not only affect photosynthesis and production in lakes, but might also further influence the microbial loop and trophic interactions via enhanced EOC under fluctuating UVR exposure.This work was supported by Ministerio Español de Medio Ambiente, Rural y Marino (PN2009/067) and Ciencia e Innovación (GLC2008-01127/BOS and CGL2011-23681), Junta de Andalucía (Excelencia CVI-02598), Agencia Nacional de Promoción Científica y Tecnológica (PICT 2007-1651) and Fundación Playa Unión; GH and CD were supported by the Spanish Government – Formación de Profesorado Universitario Grant

Algunas reflexiones sobre la resolución del problema del tablero de ajedrez

En este trabajo se parte de la perspectiva constructivista de la enseñanza y aprendizaje de las matemáticas y se considera la resolución de problemas como una actividad interesante y formativa. Se presenta el problema del tablero de ajedrez y distintos itinerarios para su trabajo, siguiendo las fases de Polya (1982) para la resolución de problemas. Finalmente se presentan algunas reflexiones sobre la resolución del problema, sobre el análisis de esta resolución y sobre la utilidad y conveniencia de este tipo de análisis para el proceso de enseñanza y aprendizaje de las matemáticas

Geometría con papel

Argumentamos sobre el uso de la papiroflexia como recurso didáctico en el aula de matemáticas. A través de diversas investigaciones sobre las características que un buen material didáctico debe tener se avala la importancia de la papiroflexia en la enseñanza y aprendizaje de las matemáticas. Proporcionamos unas sugerencias didácticas, que invitan a la reflexión sobre el papel de la geometría dentro del currículo. Por último, consideramos el valor de la papiroflexia como estímulo de distintas facultades intelectuales y físicas

Poliedros: lenguaje y representación espacial

En esta comunicación ponemos de manifiesto la importancia del estudio de los poliedros en la Enseñanza Secundaria y su utilidad para el desarrollo y la comunicación de ideas matemáticas. Con esta intención planteamos una serie de tareas que permiten al profesor y al alumno trabajar los poliedros potenciando el lenguaje en el aula de matemáticas y las capacidades espaciales del alumno. Las tareas aquí presentadas fueron realizadas en unas Jornadas de Investigación en el aula de matemáticas organizadas por la Sociedad de Profesores de Matemáticas THALES en Granada con la participación de profesores de distintos niveles educativos

Materiales didácticos en la resolución de problemas

Este trabajo se centra en la resolución de problemas y en el uso de materiales didácticos. En primero lugar, describiremos cada uno de estos elementos y las relaciones que existen entre ambos. Seguidamente, basándonos en la importancia de estas relaciones, describiremos el taller y particularizaremos en las tareas propuestas y en la utilización de algunos materiales para la resolución de problemas

Synergistic effects of UVR and simulated stratification on commensalistic phytoplankton–bacteria relationship in two optically contrasting oligotrophic Mediterranean lakes

An indirect effect of global warming is a reduction in the depth of the upper mixed layer (UML) causing organisms to be exposed to higher levels of ultraviolet (UVR, 280–400 nm) and photosynthetically active radiation (PAR, 400–700 nm). This can affect primary and bacterial production as well as the commensalistic phytoplankton–bacteria relationship. The combined effects of UVR and reduction in the depth of the UML were assessed on variables related to the metabolism of phytoplankton and bacteria, during in situ experiments performed with natural pico- and nanoplankton communities from two oligotrophic lakes with contrasting UVR transparency (high-UVR versus low-UVR waters) of southern Spain. The negative UVR effects on epilimnetic primary production (PP) and on heterotrophic bacterial production (HBP), intensified under increased stratification, were higher in the low-UVR than in the high-UVR lake, and stronger on the phytoplanktonic than on the heterotrophic bacterial communities. Under UVR and increased stratification, the commensalistic phytoplankton–bacteria relationship was strengthened in the high-UVR lake where excretion of organic carbon (EOC) rates exceeded the bacterial carbon demand (BCD; i.e., BCD : EOC(%) ratio 100). The greater UVR damage to phytoplankton and bacteria and the weakening of their commensalistic interaction found in the low-UVR lake indicates that these ecosystems would be especially vulnerable to UVR and increased stratification as stressors related to global climate change. Thus, our findings may have important implications for the carbon cycle in oligotrophic lakes of the Mediterranean region.This study was supported by the Ministerio Español de Medio Ambiente, Rural y Marino (PN2009/067), Ciencia e Innovación (CGL2011-23681), Junta de Andalucía (Excelencia CVI-02598 and P09-RNM-5376), Consejo Nacional de Investigaciones Científicas y Técnicas – CONICET (PIP no. 112-201001-00228), and Fundación Playa Unión. G. Herrera and C. Durán were supported by a Formación de Profesorado Universitario grant from the Spanish government. The authors are indebted to the staff of Sierra Nevada National Park and Lagunas de Ruidera Natural Park for permission to work, to E. Jiménez-Coll for the bacterial production analysis, and to D. Nesbitt for writing assistance in English

Alteraciones de la aorta ascendente en un modelo animal espontáneo de válvula aórtica bicúspide

La válvula aórtica bicúspide (VAB) es la malformación cardiaca congénita más prevalente y se asocia frecuentemente con dilatación de la aorta ascendente (DAA). Existen dos hipótesis etiológicas sobre esta asociación: 1) genética: VAB y alteraciones estructurales de la pared aórtica son el resultado de un mismo defecto embrionario; 2) hemodinámica: alteraciones del flujo causadas por el defecto valvular provocan la aortopatía. El sustrato histopatológico de la DAA es la necrosis cística de la media (NCM): disrupción de las lamelas elásticas, muerte de las células musculares lisas, acúmulo de sustancia basófila en áreas acelulares, ausencia de fibrosis o inflamación. Se desconoce si durante la patogénesis de la DAA, la disrupción de la elástica precede a la muerte celular o si esta última es la causa original. Contamos con el único modelo animal espontáneo de VAB, consistente en una cepa consanguínea de hámsteres con una incidencia de VAB cercana al 40% (CE). Hemos investigado la anatomía e histología de la aorta en 148 animales de la CE y 71 de una cepa control (CC), desde la juventud a la senectud. En los animales de la CC, el diámetro de la aorta ascendente aumentó progresivamente con la edad (incremento del 22% en 1,5 años), mientras que en los de la CE permaneció constante hasta la vejez (15 meses), pero aumentó súbita y significativamente (19%) en los últimos 3 meses. Comparada con la CC, la media aórtica de los hámsteres adultos de la CE presentó mayor grosor, número de lamelas, grado de ondulación de las lamelas y muerte de las células musculares lisas. La muerte celular originó áreas acelulares con acúmulo de sustancia basófila, sin presencia de inflamación ni fibrosis. No se detectó disrupción de las lamelas elásticas. Las diferencias observadas fueron de tipo cuantitativo, no cualitativo, y se detectaron entre animales de la CE y la CC, pero no entre animales de la CE con VAB o con VAT. Presentamos el primer modelo animal espontáneo de alteraciones de la aorta asociadas a la VAB. Nuestros resultados indican que la NCM es una proceso degenerativo de la aorta asociado a la senectud, cuyo factor desencadenante es la muerte de las células musculares lisas. El hecho de que los hámsteres consanguíneos de la CE presenten alteraciones en la aorta independientemente del morfotipo valvular apoya la hipótesis genética sobre la asociación entre VAB y DAA.Universidad de Málaga. Campus de Excelencia. Internacional Andalucía Tech. P10-CTS-6068 (Junta de Andalucía. Red de Investigación Cardiovascular (RIC; RETICs

Crystallization Process and Site-Selective Excitation of Nd3+ in LaF3/NaLaF4 Sol–Gel-Synthesized Transparent Glass-Ceramics

In this study, transparent oxyfluoride glass-ceramics (GCs) with NaLaF4 nanocrystals (NCs) were prepared by the sol–gel method for the first time. Three different molar ratios of La(CH3COO)3/Na(CH3COO) were used to obtain the GCs, which were sintered at 450, 550 and 650 °C for 1 min. X-ray diffraction (XRD) was employed to follow the evolution of the xerogel during the heat treatments and to study crystal growth for the three temperatures. In all cases, the LaF3 crystalline phase was present, but crystallization of NaLaF4 was only promoted at 650 °C. Thermogravimetric and thermodifferential analysis (TGA-DTA) and Fourier transform infrared spectroscopy (FTIR) were used to analyze the crystallization process. High-resolution transmission electron microscopy (HRTEM) was employed to confirm NaLaF4 crystallization and determine the size distribution. The incorporation of Nd3+ ion into NaLaF4 and LaF3 nanocrystals was confirmed by site-selective emission and excitation spectra. The Nd3+ emission intensities in both phases depend not only on the NaLaF4/LaF3 ratio but also on their emission efficiencies.The authors acknowledge financial support from MINECO under projects MAT2017-87035-C2-1-P/-2-P (AEI/FEDER, UE), and Basque Government PIBA2018-24. This article is a part of the dissemination activities of the project FunGlass, which has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No 739566

Demonstration of Patient-Specific Simulations to Assess Left Atrial Appendage Thrombogenesis Risk

Atrial fibrillation (AF) alters left atrial (LA) hemodynamics, which can lead to thrombosis in the left atrial appendage (LAA), systemic embolism and stroke. A personalized risk-stratification of AF patients for stroke would permit improved balancing of preventive anticoagulation therapies against bleeding risk. We investigated how LA anatomy and function impact LA and LAA hemodynamics, and explored whether patient-specific analysis by computational fluid dynamics (CFD) can predict the risk of LAA thrombosis. We analyzed 4D-CT acquisitions of LA wall motion with an in-house immersed-boundary CFD solver. We considered six patients with diverse atrial function, three with either a LAA thrombus (removed digitally before running the simulations) or a history of transient ischemic attacks (LAAT/TIA-pos), and three without a LAA thrombus or TIA (LAAT/TIA-neg). We found that blood inside the left atrial appendage of LAAT/TIA-pos patients had marked alterations in residence time and kinetic energy when compared with LAAT/TIA-neg patients. In addition, we showed how the LA conduit, reservoir and booster functions distinctly affect LA and LAA hemodynamics. Finally, fixed-wall and moving-wall simulations produced different LA hemodynamics and residence time predictions for each patient. Consequently, fixed-wall simulations risk-stratified our small cohort for LAA thrombosis worse than moving-wall simulations, particularly patients with intermediate LAA residence time. Overall, these results suggest that both wall kinetics and LAA morphology contribute to LAA blood stasis and thrombosis.This work was partially supported by the Comunidad de Madrid (Sinergias Y2018/BIO-4858 PREFI-CM), Cátedra Excelencia UC3M-Santander, Ministry of Education of Spain (Salvador de Madariaga program), the US NHLBI (NCAI-UCCAI-2017-06-6), the United States American Heart Association (AHA 20POST35200401), and the 2019 UCSD GEM Program. Computational time provided by XSEDE (Comet) and RES (Altamira) is gratefully acknowledged