110 research outputs found

    Computed tomography angiography, perforator flaps, surgeon and OsiriX

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    Desde la introducción de la transferencia cutánea basada en perforantes, la angiotomografía computerizada ha emergido como una técnica de gran valor en la planificación preoperatoria de los colgajos de perforante. Sin embargo, parece probable que el aprovechamiento de la técnica sea menor del deseable. Evaluamos, a través de la experiencia en 144 pacientes, la utilidad del visor gratuito de imágenes DICOM OsiriX para Mac en la planificación preoperatoria de los colgajos de perforante con tres objetivos: 1) ampliar los conocimientos actuales relacionados con la aplicación de la angiotomografía computerizada en la planificación preoperatoria de los colgajos de perforante, 2) evaluar la aplicación OsiriX en el post-procesamiento de imágenes en la planificación preoperatoria de colgajos de perforante y 3) evaluar el rendimiento obtenible de la angiotomografía considerando que el postprocesamiento es realizado por un cirujano (no especialista en Radiodiagnóstico). La experiencia permite afirmar que el postprocesamiento de las imágenes DICOM por el cirujano con la aplicación Osirix permite habitualmente evaluar de manera adecuada diversas estructuras y parámetros de gran interés en la cirugía de colgajos de perforante: 1) arteria principal, origen de la perforante, 2) diámetro de arteria y vena/s en el hipotético sitio de anastomosis microquirúrgica, 3) recorrido y patrón de ramificación del pedículo del colgajo, 4) disposición de la perforante en la grasa subcutánea (teórico eje de diseño del colgajo), 5) medición del grosor cutáneo en el punto de perforación de la fascia profunda por la rama perforante (teórico grosor de colgajo), 6) medición de la distancia entre el punto de perforación de la fascia profunda por la rama perforante y el origen de la arteria principal (teórica longitud máxima posible de pedículo) y 7) medición del diámetro, en el punto de perforación de la fascia profunda, de la perforante. En consecuencia, parece aconsejable que el cirujano plástico relacionado con los colgajos de perforante se involucre decididamente en el postprocesamiento de las imágenes de angiotomografía computerizada. El visor de imágenes DICOM gratuito OsiriX es una alternativa eficiente, comparable a aplicaciones más profesionales sólo disponibles en servicios de Radiología.With the advent of perforator-based skin transfer, computed tomography angiography has emerged as an invaluable tool in the preoperative planning of perforator flaps. But most likely, the exploitation of the technique is less than desirable. Through our experience with 144 patients, we evaluate the use of the free DICOM viewer OsiriX for Mac in the preoperative planning of perforator flaps with three objectives: 1) increase the present knowledge related with the preoperative planning of perforator flaps with computed tomography angiography, 2) evaluate the OsiriX application in the image post-processing of perforator flaps and 3) evaluate the performance of the procedure when performed by a surgeon (not specialized in Radiology). The experience has shown that the image post-processing performed by the surgeon with the OsiriX application usually allows an adequate evaluation of different structures and parameters of great preoperative interest in perforator flap surgery: 1) source artery, 2) diameter of artery and vein/s at the hypothetical site of microsurgical anastomoses, 3) course and branching pattern of the flap pedicle, 4) perforator course in the subcutaneous fat (theoretical flap axis), 5) measurement of the skin and fat where the perforator pierces the deep fascia (theoretical flap thickness ), 6) measurement of the distance between the point of entrance of the perforator in the subcutaneous fat to the source artery (theoretical maximal pedicle length) and 7) measurement of the perforator diameter where it pierces the deep fascia. Ultimately, in the authors’ opinion, those plastic surgeons involved in perforator flap surgery would largely benefit from incorporating the image post-processing into their routine practice. The free DICOM viewer OsiriX is an efficient alternative, comparable to the more professional software only available in Radiology service

    Structural stability of Fe5Si3 and Ni2Si studied by high-pressure x-ray diffraction and ab initio total-energy calculations

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    We performed high-pressure angle dispersive x-ray diffraction measurements on Fe5Si3 and Ni2Si up to 75 GPa. Both materials were synthesized in bulk quantities via a solid-state reaction. In the pressure range covered by the experiments, no evidence of the occurrence of phase transitions was observed. On top of that, Fe5Si3 was found to compress isotropically, whereas an anisotropic compression was observed in Ni2Si. The linear incompressibility of Ni2Si along the c-axis is similar in magnitude to the linear incompressibility of diamond. This fact is related to the higher valence-electron charge density of Ni2Si along the c-axis. The observed anisotropic compression of Ni2Si is also related to the layered structure of Ni2Si where hexagonal layers of Ni2+ cations alternate with graphite-like layers formed by (NiSi)2- entities. The experimental results are supported by ab initio total-energy calculations carried out using density functional theory and the pseudopotential method. For Fe5Si3, the calculations also predicted a phase transition at 283 GPa from the hexagonal P63/mcm phase to the cubic structure adopted by Fe and Si in the garnet Fe5Si3O12. The room-temperature equations of state for Fe5Si3 and Ni2Si are also reported and a possible correlation between the bulk modulus of iron silicides and the coordination number of their minority element is discussed. Finally, we report novel descriptions of these structures, in particular of the predicted high-pressure phase of Fe5Si3 (the cation subarray in the garnet Fe5Si3O12), which can be derived from spinel Fe2SiO4 (Fe6Si3O12).Comment: 44 pages, 13 figures, 3 Table

    Hydrogeochemical characteristics of the Saliencia lakes (Somiedo Natural Park, NW Spain): trophic state and relationship with anthropogenic pressures

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    The high-mountain lakes of Saliencia (El Valle, La Cueva, Calabazosa and Cerveriz), in the Somiedo Natural Park (Asturias, NW Spain), have been subject to different anthropogenic pressures, including metal mining, cattle grazing, damming activities and water channelling work for hydroelectric exploitation. This paper reports the results of a recent geochemical and limnological study conducted in these lakes, for which no previous study existed in the literature. Based on depth profiles of temperature, conductivity, pH and ORP, as well as dissolved oxygen, chlorophyll-a, organic carbon, nutrient and metal concentration, we discuss the impact of anthropogenic pressure on the lakes. In the sampling period (July to September, 2014-2016), most of the lakes showed a marked stratification with vertical gradients as a result of different physical and (bio)geochemical processes. All the lakes showed a good environmental state with no apparent metal pollution. However, this set of mountain lakes is not homogeneous with regard to nutrient availability, primary productivity, or hypolimnetic oxygen deficit and a range of trophic conditions exist from oligotrophic (El Valle) to eutrophic (Calabazosa). This trend shows a good correlation with total phosphorus concentration (e.g., 10 µg/L P in El Valle vs. 35 µg/L P in Calabazosa), though erosive processes in the catchment may also have contributed to increase the oxygen consumption rate through an import of allochthonous organic matter. Higher nitrate contents seem to characterize the areas with higher grazing pressure (e.g., El Valle), though the obtained data do not allow us to establish any evident relationship between cattle activity and eutrophication

    Compressibility systematics of calcite-type borates : An experimental and theoretical structural study on ABO3 (A = Al, Sc, Fe and In)

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    This document is the Accepted Manuscript version of a Published Work that appeared in final form in Journal of Physical Chemistry C , copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://dx.doi.org/10.1021/jp4124259The structural properties of calcite-type orthoborates ABO(3) (A = Al, Fe, Sc, and In) have been investigated at high pressures up to 32 GPa. They were studied experimentally using synchrotron powder X-ray diffraction and theoretically by means of ab initio total-energy calculations. We found that the calcite-type structure remains stable up to the highest pressure explored in the four studied compounds. Experimental and calculated static geometries (unit-cell parameters and internal coordinates), bulk moduli, and their pressure derivatives are in good agreement. The compressibility along the c axis is roughly three times that along the a axis. Our data clearly indicate that the compressibility of borates is dominated by that of the [AO(6)] octahedral group and depends on the size of the trivalent A cations. An analysis of the relationship between isomorphic borates and carbonates is also presented, which points to the potentiality of considering borates as chemical analogues of the carbonate mineral family.This study was supported by the Spanish government MEC under Grant Nos.: MAT2010-21270-C04-01/03/04 and CTQ2009-14596-C02-01, by MALTA Consolider Ingenio 2010 Project (CSD2007-00045), by Generalitat Valenciana (GVA-ACOMP-2013-1012), and by the Vicerrectorado de Investigacion y Desarrollo of the Universidad Politecnica de Valencia (UPV2011-0914 PAID-05-11 and UPV2011-0966 PAID-06-11). We thank ALBA and Diamond synchrotrons for providing beamtime for the XRD experiments. A.M. and P.R-H. acknowledge computing time provided by Red Espanola de Supercomputacion (RES) and MALTA-Cluster. J.A.S. and B.G.-D. acknowledge Juan de la Cierva fellowship and FPI programs for financial support. We are gratefully indebted to Dr. Capponi and Dr. Diehl for supplying us single crystals of AlBO3 and FeBO3, respectively.Santamaría Pérez, D.; Gomis Hilario, O.; Sans, JÁ.; Ortiz, HM.; Vegas, Á.; Errandonea, D.; Ruiz-Fuertes, J.... (2014). Compressibility systematics of calcite-type borates : An experimental and theoretical structural study on ABO3 (A = Al, Sc, Fe and In). Journal of Physical Chemistry C. 118(8):4354-4361. https://doi.org/10.1021/jp4124259S43544361118

    Phase behaviour of Ag2CrO4 under compression: Structural, vibrational, and optical properties

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    This document is the Accepted Manuscript version of a Published Work that appeared in final form in Journal of Physical Chemistry C, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://dx.doi.org/10.1021/jp401524sWe have performed an experimental study of the crystal structure, lattice dynamics, and optical properties of silver chromate (Ag2CrO4) at ambient temperature and high pressures. In particular, the crystal structure, Raman-active phonons, and electronic band gap have been accurately determined. When the initial orthorhombic Pnma Ag2CrO4 structure (phase I) is compressed up to 4.5 GPa, a previously undetected phase (phase II) has been observed with a 0.95% volume collapse. The structure of phase II can be indexed to a similar orthorhombic cell as phase I, and the transition can be considered to be an isostructural transition. This collapse is mainly due to the drastic contraction of the a axis (1.3%). A second phase transition to phase III occurs at 13 GPa to a structure not yet determined. First-principles calculations have been unable to reproduce the isostructural phase transition, but they propose the stabilization of a spinel-type structure at 11 GPa. This phase is not detected in experiments probably because of the presence of kinetic barriers. Experiments and calculations therefore seem to indicate that a new structural and electronic description is required to model the properties of silver chromate.This study was supported by the Spanish government MEC under grants MAT2010-21270-C04-01/03/04 and CTQ2009-14596-C02-01, by the Comunidad de Madrid and European Social Fund (S2009/PPQ1551 4161893), by the MALTA Consolider Ingenio 2010 project (CSD2007-00045), and by the Vicerrectorado de Investigacion y Desarrollo of the Universidad Politecnica de Valencia (UPV2011-0914 PAID-05-11 and UPV2011-0966 PAID-06-11). A.M. and P.R.-H. acknowledge computing time provided by Red Espanola de Supercomputacion (RES) and MALTA-Cluster. J.A.S. acknowledges Juan de la Cierva Fellowship Program for its financial support. Diamond and ALBA Synchrotron Light Sources are acknowledged for provisions of beam time. We also thank Drs. Peral, Popescu, and Fauth for technical support.Santamaría Pérez, D.; Bandiello, E.; Errandonea, D.; Ruiz-Fuertes, J.; Gomis Hilario, O.; Sans, JÁ.; Manjón Herrera, FJ.... (2013). Phase behaviour of Ag2CrO4 under compression: Structural, vibrational, and optical properties. Journal of Physical Chemistry C. 117(23):12239-12248. https://doi.org/10.1021/jp401524sS12239122481172

    PETER building : an example of integration of renewable energies into the edification

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    El objetivo principal del presente artículo es mostrar y dar a conocer las aplicaciones de la edificación bioclimática, sus ventajas y características. Para ello, se muestra el proyecto de Construcción de un Edificio Inteligente de “Energía Convencional Cero” (“Bioclimático”) de unos 1700 m2 en el Campus de la Universidad de Extremadura en Badajoz. Se pondrán en práctica los conceptos sobre ahorro y eficiencia energética en la edificación, así como la integración de las energías renovables en el edificio PETER. Además se mostrará como es posible en ciudades de clima extremo (como es la ciudad de Badajoz, con necesidad de calefacción en invierno y de refrigeración en verano), climatizar edificios aplicando medidas que minimizan el consumo energético. Finalmente, se lleva a cabo un proceso de simulación energética que permite comprobar el comportamiento energético del edificio.The present article is intended to show the main features, advantages and applications of bioclimatic architecture as well as the the integration of renewable energies ito the edification. For such purpose, the Project of an approximate 1 700 m2 intelligent zeroconventional- energy (“Bioclimatic”) building (referred to as PETER Project (Experimental Transborder Park on Renewable Energies)), to be located in the Campus of the University of Extremadura in Badajoz, is described. Specific principles directly relating building design, like energy saving, energy efficient and integration of renewable energy sources, are put in practice. In addition will be shown as it is possible in cities of extreme climate (as it is the city of Badajoz, with necessity of heating in winter and refrigeration in summer), to acclimate buildings applying measures that diminish the power consumption. Finally, a description of the energy response of the building is carried out via computer simulation techniques

    Historia geológica y reconstrucción paleobiológica de los depósitos paleontológicos de la playa de El Confital (Gran Canaria, islas Canarias)

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    XXXIV Jornadas de Paleontología y IV Congreso Ibérico de Paleontología (Vila Real, Portugal. Sep 2018) p. 491-499El archipiélago canario está situado cerca de la costa NO de África y es de naturaleza volcánica. Fuerteventura y Lanzarote son las islas más antiguas del archipiélago (23 y 15 Ma aproximadamente) seguidas por Gran Canaria (14 Ma), siendo en estas tres islas solamente donde vamos a encontrar depósitos fosilíferos pertenecientes a las series Mioceno y Plioceno (Meco et al., 2015). El episodio MIS5e (Eemiense), por el contrario, podemos encontrarlo en todas las islas (Meco et al., 2002; Zazo et al., 2003; Martín-González et al., 2016). Este trabajo se centra en el estudio de los depósitos fosilíferos asociados a ambos periodos que aparecen en la playa de El Confital, en la isla de Gran Canaria Los afloramientos se encuentran al suroeste de La Isleta, un islote eminentemente volcánico situado en el extremo NE de Las Palmas de Gran Canaria unido al edificio insular principal por un tómbolo de arena, el istmo de Guanarteme. Se trata de una plataforma litoral activa modelada sobre piroclastos de origen hidromagmático (Hansen, 2008), que ha sido alterada antrópicamente en tiempos recientes. Las Palmas de Gran Canaria constituye uno de los escasos ejemplos en los que se pueden observar yacimientos paleontológicos de diferentes edades. En la parte alta de la ciudad se encuentra la Formación Detrítica de Las Palmas, de edad Mio-Plioceno, que contiene una importante asociación fosilífera estudiada por diferentes autores (Rothpletz & Simonelli, 1890; Meco et al., 2007; Betancort, 2012; Martín-González et al., 2018); mientras que en la zona baja se encuentran los afloramientos pertenecientes al episodio transgresivo marino MIS5e (Meco et al., 2002). En la playa de El Confital podemos encontrar, en ambos extremos, los yacimientos del Eemiense, al sur, cuyo estudio paleontológico y estratigráfico preliminar fue realizado por Cabrera (1987) y del Mioceno, al noroeste, donde Meco et al. (2015) citan por primera vez la existencia del nivel con Ostrea offretti Linnaeus. En este trabajo realizamos un análisis volcano-estratigráfico y paleontológico integral de la playa de El Confital con el fin de reconstruir la evolución temporal de la fauna fosilizada en esta zona.Museo de Ciencias Naturales (MCN). OAMCÁrea de Paleontología, Facultad de Biología, Universidad de La LagunaDpto. de Geologia, Faculdade de Ciências, Universidade de LisboaCIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, InBIO Laboratório Associado, Pólo dos AçoresInstituto Dom Luiz, Faculdade de Ciências da Universidade de LisboaUnidad Territorial de Canarias, Instituto Geológico y Minero de España (IGME)IOCAG. Instituto de Oceanografía y Cambio Global. Universidad de Las Palmas de Gran CanariaTELLUS. Arqueología y Prehistoria en el Sur de Iberia. HUM-949Department of Geosciences, Williams CollegeDpto. de Geografía. Universidad de La LagunaÁrea de Patrimonio Geológico y Minero, Instituto Geológico y Minero de España (IGME).Área de Geología. Universidad Rey Juan Carlo

    COVID-19 : Age, Interleukin-6, C-reactive protein, and lymphocytes as key clues from a multicentre retrospective study

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    Background: The SARS-CoV-2 infection has widely spread to become the greatest public health challenge to date, the COVID-19 pandemic. Different fatality rates among countries are probably due to non-standardized records being carried out by local health authorities. The Spanish case-fatality rate is 11.22%, far higher than those reported in Asia or by other European countries. A multicentre retrospective study of demographic, clinical, laboratory and immunological features of 584 Spanish COVID-19 hospitalized patients and their outcomes was performed. The use of renin-angiotensin system blockers was also analysed as a risk factor. Results: In this study, 27.4% of cases presented a mild course, 42.1% a moderate one and for 30.5% of cases, the course was severe. Ages ranged from 18 to 98 (average 63). Almost 60 % (59.8%) of patients were male. Interleukin 6 was higher as severity increased. On the other hand, CD8 lymphocyte count was significantly lower as severity grew and subpopulations CD4, CD8, CD19, and NK showed concordant lowering trends. Severity-related natural killer percent descents were evidenced just within aged cases. A significant severity-related decrease of CD4 lymphocytes was found in males. The use of angiotensin-converting enzyme inhibitors was associated with a better prognosis. The angiotensin II receptor blocker use was associated with a more severe course. Conclusions: Age and age-related comorbidities, such as dyslipidaemia, hypertension or diabetes, determined more frequent severe forms of the disease in this study than in previous literature cohorts. Our cases are older than those so far reported and the clinical course of the disease is found to be impaired by age. Immunosenescence might be therefore a suitable explanation for the hampering of immune system effectors. The adaptive immunity would become exhausted and a strong but ineffective and almost deleterious innate response would account for COVID-19 severity. Angiotensin-converting enzyme inhibitors used by hypertensive patients have a protective effect in regards to COVID-19 severity in our series. Conversely, patients on angiotensin II receptor blockers showed a severer disease

    Pbca-Type In2O3: the high-pressure post-corundum phase at room temperature

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    This document is the Accepted Manuscript version of a Published Work that appeared in final form in Journal of Physical Chemistry C, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://dx.doi.org/10.1021/jp5061599High-pressure powder X-ray diffraction and Raman scattering measurements in cubic bixbyite-type indium oxide (c-In2O3) have been performed at room temperature. On increasing pressure c-In2O3 undergoes a transition to the Rh2O3-II structure but on decreasing pressure Rh2O3-II-type In2O3 undergoes a transition to a previously unknown phase with Pbca space group which is isostructural to Rh2O3-III. On further decrease of pressure, we observed a phase transition to the metastable corundum-type In2O3 near room conditions. Recompression of the metastable corundum-type In2O3 at room temperature leads to a transition to the Rh2O3-III phase, thus showing that the Rh2O3-III phase is the post-corundum phase at room temperature. Our results are supported by theoretical ab initio calculations. Furthermore, they show that the Rh2O3-III phase could be present in other sesquioxides, thus prompting to a revision of the pressure-temperature phase diagrams of sesquioxidesFinancial support by the Spanish MEC under Grant No. MAT2010-21270-C04-01/03/04, MAT2013-46649-C4-1/2/3-P, by MALTA Consolider Ingenio 2010 project (CSD2007-00045) and by Generalitat Valenciana (GVA-ACOMP-2013-012). Red Espanola de Supercomputacion (RES) and ALBA Synchrotron Light Source are also acknowledged. B.G.-D. and J.A.S. acknowledge financial support through the FPI program and Juan de la Cierva fellowship, respectively. We also thank J. L. Jorda for fruitful discussions. A.L.J.P. acknowledges financial support through Brazilian CNPq. A.S. expresses thanks to FEDER Grant UNLV10-3E-1253 for financial support.García-Domene, B.; Sans Tresserras, JÁ.; Gomis, O.; Manjón Herrera, FJ.; Ortiz, HM.; Errandonea, D.; Santamaría Pérez, D.... (2014). Pbca-Type In2O3: the high-pressure post-corundum phase at room temperature. Journal of Physical Chemistry C. 118(35):20545-20552. https://doi.org/10.1021/jp5061599S20545205521183
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