284 research outputs found

    Built-up AFM tips by metal nanoclusters engineering

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    The ability to probe tip-sample interactions by Atomic Force Microscopy (AFM) has recently boosted our understanding of the matter at the atomic scale, enabling the study of properties of surfaces and adsorbates which were previously inaccessible. Nevertheless, this sensitivity to forces presents some drawbacks, as the requirement of a sharp tip apex to prevent the loss of spatial resolution due to the existence of long-range interactions. In this work, we have overcome this long-standing challenge by investigating the controlled extraction of single metallic nanoclusters, selectively grown on graphene. Our results show that the successive extraction of cluster allows to grow nanotips, which minimize the long-range tip-sample interactions and greatly enhance the topographic resolution. We have demonstrated that the created nanotips are very stable, which enables exchanging the sample and using the same nanotip to explore different surfaces without loss of resolution. Since metallic clusters of very different materials and sizes can be grown and selectively extracted by AFM, ours work paves also the way to the specific functionalization of AFM-tips to sense a large variety of interactionsFinancial support from the Spanish Ministerio de Economía y Competitividad (MINECO) and Fondo Europeo de Desarrollo Regional (FEDER) under grants No. MAT2016-77852-C2-2-R and MAT2016-80907-P and by the Comunidad de Madrid NMAT2D-CM program under grant S2018/NMT-4511 is gratefully acknowledged. Financial support from the Spanish Ministerio de Ciencia e Innovacion under grant Nº PID2019-106268GB-C31 is also gratefully acknowledged. We thank Rubén Pérez and Oscar Custance for helpful discussions and Antonio J. Martínez-Galera for helpful discussions and technical assistanc

    Sistema multiobjetivo de soporte a decisiones para planificación de programación de operaciones

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    This research shows the design and construction of a multi objective optimization support system for decision making, DSS-SCHEDULER, in order to effectively perform naval shipbuilding operations, by managing to have a rational usage, under a limited capacity, of the installed capacity. The system creates the operational plan for the scheduling of operations as well as the allocation of all the resources related to the processes carried out at the plant, and, taking into account all the restrictions this type of service entails, generate a set of optimal solutions in order to comply with the objective functions as planned, such as costs and the promise for delivery dates to support the decision making process in scheduling Cotecmar’s industrial operations.La presente investigación muestra el diseño y construcción de un sistema de optimización Multiobjetivo de soporte a toma de decisiones, DSS-SCHEDULER, para realizar de manera efectiva la actividad de programación de operaciones en planta de astilleros navales, logrando una utilización racional, bajo capacidad finita, de la capacidad instalada, el cual realiza la creación de la planificación operativa de programación de operaciones y la asignación de todos los recursos asociados a los procesos que se realizan en la planta, y teniendo en cuenta todas las restricciones que conlleva estos servicios, generar un conjunto de soluciones óptimas cumpliendo con las funciones objetivo propuestas, como costos y promesa de fechas de entrega para apoyar la toma de decisiones de la programación de las operaciones industriales de Cotecmar

    Comparativa del uso de HLLs en FPGA, GPU y Multicore para la aceleración de una aplicación de red IP

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    Afrontar la creación de aplicaciones a partir de lenguajes de alto nivel (High Level Lenguajes - HLLs) tiene la incuestionable ventaja de reducir el tiempo de desarrollo. Con ello, es viable una evaluación anticipada del prototipo para conocer cuanto antes si se alcanza el rendimiento especificado como objetivo. En este trabajo se han utilizando tres tecnologías de aceleración: multicore, coprocesador gráfico y coprocesador reconfigurable, que aprovechan el procesamiento paralelo, y se ha realizado una discusión crítica de su experiencia de uso a través de abstracciones de alto nivel. Las soluciones basadas en el uso de coprocesadores no sólo han aportado un nivel de rendimiento superior a la aplicación que se deseaba acelerar, sino que con vista al sistema final en producción, estas alternativas son especialmente interesantes por dejar libres los cores de procesamiento para la realización de las operaciones de envío/recepción en la red de comunicaciones

    Tip and Surface Determination from Experiments and Simulations of Scanning Tunneling Microscopy and Spectroscopy

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    We present a very efficient and accurate method to simulate scanning tunneling microscopy images and spectra from first-principles density functional calculations. The wave-functions of the tip and sample are calculated separately on the same footing, and propagated far from the surface using the vacuum Green's function. This allows to express the Bardeen matrix elements in terms of convolutions, and to obtain the tunneling current at all tip positions and bias voltages in a single calculation. The efficiency of the method opens the door to real time determination of both tip and surface composition and structure, by comparing experiments to simulated images for a variety of precomputed tips. Comparison with the experimental topography and spectra of the Si(111)-(7x7) surface show a much better agreement with Si than with W tips, implying that the metallic tip is terminated by silicon.Comment: 4 pages, 4 figure

    Síndrome de Mirizzi tipo V: manejo laparoscópico

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    Introduction: Mirizzi's syndrome is an infrequent complication of biliary lithiasic disease, with an incidence of less than 1% in developed countries, being even less frequent the type V variant. Current literature disagrees on the management of this condition, stating that laparoscopic surgery is not safe as a standard procedure. Clinical Case: We present the case of Mirizzi’s Syndrome in an 80-year-old man, which is referred to the emergency department for suspicion of sepsis of abdominal origin, with ultrasound study of cholelithiasis, pneumoobilia and dilation of the bile ducts. Retrograde endoscopic cholangiopancreatography was performed with technical impossibility for the mobilization and extraction of large-size stones, resorting to exploration through laparoscopic technique, obtaining satisfactory results. Conclusion: It is necessary to emphasize that the type of Mirizzi syndrome, the patient's characteristics and the surgeon's experience directly influence the treatment modality, its complications and/or success rates. In the present case, the experience of the main author in the management of minimally invasive procedures and the consideration of reducing the risk of complications such as infections in a fragile patient, were the factors that influenced the decision for laparoscopic intervention.Introducción: El Síndrome de Mirizzi es una complicación  infrecuente de la enfermedad litiásica biliar, con una incidencia menor al 1% en países desarrollados,  puede desarrollarse en cinco variantes, siendo  menos frecuente la variante tipo V. La literatura actual discrepa sobre el manejo de esta condición, afirmando que la cirugía laparoscópica no es segura como procedimiento estándar. Caso Clínico: Se presenta el caso de Síndrome de Mirizzi en un hombre de 80 años, que es remitido al departamento de urgencias por sospecha de sepsis de origen abdominal, con estudio ecográfico de colelitiasis, neumobilia y dilatación de las vías biliares. Se realizó Colangiopancreatografía retrógrada endoscópica con imposibilidad técnica para la movilización y extracción de los cálculos por gran tamaño, recurriéndose a exploración a través de técnica laparoscópica, obteniéndose resultados satisfactorios. Conclusión: Para tratar el  Síndrome de Mirizzi, es necesario considerar  las características del paciente y la experiencia del cirujano ya que ambos factores influyen directamente en la modalidad del tratamiento, sus complicaciones y tasas de éxito. En el presente caso, la experiencia del autor principal en el manejo de procedimientos mínimamente invasivos y la consideración de reducir el riesgo de complicaciones como infecciones en un paciente frágil, fueron los factores que influyeron para la decisión de intervención laparoscópica

    Síndrome de Mirizzi tipo V: manejo laparoscópico

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    Introduction: Mirizzi's syndrome is an infrequent complication of biliary lithiasic disease, with an incidence of less than 1% in developed countries, being even less frequent the type V variant. Current literature disagrees on the management of this condition, stating that laparoscopic surgery is not safe as a standard procedure. Clinical Case: We present the case of Mirizzi’s Syndrome in an 80-year-old man, which is referred to the emergency department for suspicion of sepsis of abdominal origin, with ultrasound study of cholelithiasis, pneumoobilia and dilation of the bile ducts. Retrograde endoscopic cholangiopancreatography was performed with technical impossibility for the mobilization and extraction of large-size stones, resorting to exploration through laparoscopic technique, obtaining satisfactory results. Conclusion: It is necessary to emphasize that the type of Mirizzi syndrome, the patient's characteristics and the surgeon's experience directly influence the treatment modality, its complications and/or success rates. In the present case, the experience of the main author in the management of minimally invasive procedures and the consideration of reducing the risk of complications such as infections in a fragile patient, were the factors that influenced the decision for laparoscopic intervention.Introducción: El Síndrome de Mirizzi es una complicación  infrecuente de la enfermedad litiásica biliar, con una incidencia menor al 1% en países desarrollados,  puede desarrollarse en cinco variantes, siendo  menos frecuente la variante tipo V. La literatura actual discrepa sobre el manejo de esta condición, afirmando que la cirugía laparoscópica no es segura como procedimiento estándar. Caso Clínico: Se presenta el caso de Síndrome de Mirizzi en un hombre de 80 años, que es remitido al departamento de urgencias por sospecha de sepsis de origen abdominal, con estudio ecográfico de colelitiasis, neumobilia y dilatación de las vías biliares. Se realizó Colangiopancreatografía retrógrada endoscópica con imposibilidad técnica para la movilización y extracción de los cálculos por gran tamaño, recurriéndose a exploración a través de técnica laparoscópica, obteniéndose resultados satisfactorios. Conclusión: Para tratar el  Síndrome de Mirizzi, es necesario considerar  las características del paciente y la experiencia del cirujano ya que ambos factores influyen directamente en la modalidad del tratamiento, sus complicaciones y tasas de éxito. En el presente caso, la experiencia del autor principal en el manejo de procedimientos mínimamente invasivos y la consideración de reducir el riesgo de complicaciones como infecciones en un paciente frágil, fueron los factores que influyeron para la decisión de intervención laparoscópica

    FPGA acceleration using high-level languages of a Monte-Carlo method for pricing complex options

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    This is the author’s version of a work that was accepted for publication in Journal of Systems Architecture. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Journal of Systems Architecture, 59, 3 (2013) DOI: 10.1016/j.sysarc.2013.01.004In this paper we present an FPGA implementation of a Monte-Carlo method for pricing Asian options using Impulse C and floating-point arithmetic. In an Altera Stratix-V FPGA, a 149x speedup factor was obtained against an OpenMP-based solution in a 4-core Intel Core i7 processor. This speedup is comparable to that reported in the literature using a classic HDL-based methodology, but the development time is significantly reduced. Additionally, the use of a HLL-based methodology allowed us to implement a high-quality Gaussian random number generator, which produces more precise results than those obtained with the simple generators usually present in HDL-based designs

    Síndrome de Mirizzi tipo V: manejo laparoscópico

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    Introduction: Mirizzi's syndrome is an infrequent complication of biliary lithiasic disease, with an incidence of less than 1% in developed countries, being even less frequent the type V variant. Current literature disagrees on the management of this condition, stating that laparoscopic surgery is not safe as a standard procedure. Clinical Case: We present the case of Mirizzi’s Syndrome in an 80-year-old man, which is referred to the emergency department for suspicion of sepsis of abdominal origin, with ultrasound study of cholelithiasis, pneumoobilia and dilation of the bile ducts. Retrograde endoscopic cholangiopancreatography was performed with technical impossibility for the mobilization and extraction of large-size stones, resorting to exploration through laparoscopic technique, obtaining satisfactory results. Conclusion: It is necessary to emphasize that the type of Mirizzi syndrome, the patient's characteristics and the surgeon's experience directly influence the treatment modality, its complications and/or success rates. In the present case, the experience of the main author in the management of minimally invasive procedures and the consideration of reducing the risk of complications such as infections in a fragile patient, were the factors that influenced the decision for laparoscopic intervention.Introducción: El Síndrome de Mirizzi es una complicación  infrecuente de la enfermedad litiásica biliar, con una incidencia menor al 1% en países desarrollados,  puede desarrollarse en cinco variantes, siendo  menos frecuente la variante tipo V. La literatura actual discrepa sobre el manejo de esta condición, afirmando que la cirugía laparoscópica no es segura como procedimiento estándar. Caso Clínico: Se presenta el caso de Síndrome de Mirizzi en un hombre de 80 años, que es remitido al departamento de urgencias por sospecha de sepsis de origen abdominal, con estudio ecográfico de colelitiasis, neumobilia y dilatación de las vías biliares. Se realizó Colangiopancreatografía retrógrada endoscópica con imposibilidad técnica para la movilización y extracción de los cálculos por gran tamaño, recurriéndose a exploración a través de técnica laparoscópica, obteniéndose resultados satisfactorios. Conclusión: Para tratar el  Síndrome de Mirizzi, es necesario considerar  las características del paciente y la experiencia del cirujano ya que ambos factores influyen directamente en la modalidad del tratamiento, sus complicaciones y tasas de éxito. En el presente caso, la experiencia del autor principal en el manejo de procedimientos mínimamente invasivos y la consideración de reducir el riesgo de complicaciones como infecciones en un paciente frágil, fueron los factores que influyeron para la decisión de intervención laparoscópica

    Porcine reproductive and respiratory syndrome virus impacts on gut microbiome in a strain virulence‐dependent fashion

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    Porcine reproductive and respiratory syndrome (PRRS) is a viral disease defined by reproductive problems, respiratory distress and a negative impact on growth rate and general condition. Virulent PRRS virus (PRRSV) strains have emerged in the last years with evident knowledge gaps in their impact on the host immune response. Thus, the present study examines the impact of acute PRRS virus (PRRSV) infection, with two strains of different virulence, on selected immune parameters and on the gut microbiota composition of infected pigs using 16S rRNA compositional sequencing. Pigs were infected with a low virulent (PRRS_3249) or a virulent (Lena) PRRSV‐1 strain and euthanized at 1, 3, 6, 8 or 13 days post‐inoculation (dpi). Faeces were collected from each animal at the necropsy time‐point. Alpha and beta diversity analyses demonstrated that infection, particularly with the Lena strain, impacted the microbiome composition from 6 dpi onwards. Taxonomic differences revealed that infected pigs had higher abundance of Treponema and Methanobrevibacter (FDR < 0.05). Differences were more considerable for Lena‐ than for PRRS_3249‐infected pigs, showing the impact of strain virulence in the intestinal changes. Lena‐infected pigs had reduced abundancies of anaerobic commensals such as Roseburia, Anaerostipes, Butyricicoccus and Prevotella (P < 0.05). The depletion of these desirable commensals was significantly correlated to infection severity measured by viraemia, clinical signs, lung lesions and immune parameters (IL‐6, IFN‐γ and Hp serum levels). Altogether, the results from this study demonstrate the indirect impact of PRRSV infection on gut microbiome composition in a strain virulence‐dependent fashion and its association with selected immune markers.info:eu-repo/semantics/publishedVersio

    Porcine reproductive and respiratory syndrome virus impacts on gut microbiome in a strain virulence‐dependent fashion

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    [EN] Porcine reproductive and respiratory syndrome (PRRS) is a viral disease defined by reproductive problems, respiratory distress and a negative impact on growth rate and general condition. Virulent PRRS virus (PRRSV) strains have emerged in the last years with evident knowledge gaps in their impact on the host immune response. Thus, the present study examines the impact of acute PRRS virus (PRRSV) infection, with two strains of different virulence, on selected immune parameters and on the gut microbiota composition of infected pigs using 16S rRNA compositional sequencing. Pigs were infected with a low virulent (PRRS_3249) or a virulent (Lena) PRRSV-1 strain and euthanized at 1, 3, 6, 8 or 13 days post-inoculation (dpi). Faeces were collected from each animal at the necropsy time-point. Alpha and beta diversity analyses demonstrated that infection, particularly with the Lena strain, impacted the microbiome composition from 6 dpi onwards. Taxonomic differences revealed that infected pigs had higher abundance of Treponema and Methanobrevibacter (FDR < 0.05). Differences were more considerable for Lena- than for PRRS_3249-infected pigs, showing the impact of strain virulence in the intestinal changes. Lena-infected pigs had reduced abundancies of anaerobic commensals such as Roseburia, Anaerostipes, Butyricicoccus and Prevotella (P < 0.05). The depletion of these desirable commensals was significantly correlated to infection severity measured by viraemia, clinical signs, lung lesions and immune parameters (IL-6, IFN-γ and Hp serum levels). Altogether, the results from this study demonstrate the indirect impact of PRRSV infection on gut microbiome composition in a strain virulence-dependent fashion and its association with selected immune markersSIJ. G omez-Laguna is supported by a ‘Ram on y Cajal’ contract of the Spanish Ministry of Economy and Competitiveness (RYC-2014-16735). Hector Arg€uello is supported by the ‘Beatriz Galindo’ Programme from the Spanish Ministry of Education (BEAGAL-18-106). This work was partially supported by the Spanish Ministry of Education and Science (AGL2016-76111-R). Research in the Cotter laboratory is funded by Science Foundation Ireland in the form of a centre grants (APC Microbiome Ireland, Grant Number SFI/12/RC/2273, and Vistamilk, Grant Number SFI/16/RC/3835) and by the European Commission under the Horizon 2020 programme under grant number 818368 (MASTER
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