464 research outputs found

    The control of metabolic CO2 in public transport as a strategy to reduce the transmission of respiratory infectious diseases

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    The global acceptance of the SARS-CoV-2 airborne transmission led to prevention measures based on quality control and air renewal. Among them, carbon dioxide (CO2) measurement has positioned itself as a cost-efficiency, reliable, and straightforward method to assess indoor air renewal indirectly. Through the control of CO2, it is possible to implement and validate the effectiveness of prevention measures to reduce the risk of contagion of respiratory diseases by aerosols. Thanks to the method scalability, CO2 measurement has become the gold standard for diagnosing air quality in shared spaces. Even though collective transport is considered one of the environments with the highest rate of COVID-19 propagation, little research has been done where the air inside vehicles is analyzed. This work explores the generation and accumulation of metabolic CO2 in a tramway (Zaragoza, Spain) operation. Importantly, we propose to use the indicator ppm/person as a basis for comparing environments under different conditions. Our study concludes with an experimental evaluation of the benefit of modifying some parameters of the Heating–Ventilation–Air conditioning (HVAC) system. The study of the particle retention efficiency of the implemented filters shows a poor air cleaning performance that, at present, can be counteracted by opening windows. Seeking a post-pandemic scenario, it will be crucial to seek strategies to improve air quality in public transport to prevent the transmission of infectious diseases

    SARS-CoV-2 Droplet and Airborne Transmission Heterogeneity

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    The spread dynamics of the SARS-CoV-2 virus have not yet been fully understood after two years of the pandemic. The virus’s global spread represented a unique scenario for advancing infectious disease research. Consequently, mechanistic epidemiological theories were quickly dismissed, and more attention was paid to other approaches that considered heterogeneity in the spread. One of the most critical advances in aerial pathogens transmission was the global acceptance of the airborne model, where the airway is presented as the epicenter of the spread of the disease. Although the aerodynamics and persistence of the SARS-CoV-2 virus in the air have been extensively studied, the actual probability of contagion is still unknown. In this work, the individual heterogeneity in the transmission of 22 patients infected with COVID-19 was analyzed by close contact (cough samples) and air (environmental samples). Viral RNA was detected in 2/19 cough samples from patient subgroups, with a mean Ct (Cycle Threshold in Quantitative Polymerase Chain Reaction analysis) of 25.7 ± 7.0. Nevertheless, viral RNA was only detected in air samples from 1/8 patients, with an average Ct of 25.0 ± 4.0. Viral load in cough samples ranged from 7.3 × 105 to 8.7 × 108 copies/mL among patients, while concentrations between 1.1–4.8 copies/m3 were found in air, consistent with other reports in the literature. In patients undergoing follow-up, no viral load was found (neither in coughs nor in the air) after the third day of symptoms, which could help define quarantine periods in infected individuals. In addition, it was found that the patient’s Ct should not be considered an indicator of infectiousness, since it could not be correlated with the viral load disseminated. The results of this work are in line with proposed hypotheses of superspreaders, which can attribute part of the heterogeneity of the spread to the oversized emission of a small percentage of infected people

    High porosity scaffold composites of graphene and carbon nanotubes as microwave absorbing materials

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    The design of microwave absorbing materials requires low reflection and high absorption of radiation simultaneously. Low reflection of electromagnetic waves can be achieved inducing porous faces which minimize the impedance mismatch. High absorption can be obtained by increasing the conductivity of the material. We report the preparation of highly porous scaffolds from a combination of graphene and carbon nanotubes. The bimodal porous structure was controlled making use of the surface properties of graphene oxide that are able to stabilize hexane droplets in aqueous dispersions of graphene oxide and carbon nanotubes. After hydrothermal and two step freeze-drying processes, macro-(220 microns) and mesoporous (10 microns) structures, due to hexane droplets and freeze drying, respectively, were obtained. DC conductivities of 8.2, 14.7, 33.2, and 60.7 S m(-1) were obtained for graphene scaffolds containing 0, 10, 20 and 40% of carbon nanotubes respectively. An electromagnetic characterization was performed on scaffolds infiltrated with epoxy resin; using appropriate models, the electromagnetic properties of the conducting phase have been obtained. Scaffolds with a thickness of 9 mm were able to absorb up to 80% of the incident radiation keeping the reflection as low as 20%.This work was supported by grant NANONARQ (MAT2014-57557-R) from the Spanish Ministerio de Economía y Competitividad

    Carbon Nanotube Composites as Electromagnetic Shielding Materials in GHz Range

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    Following the development of the new electronic systems and communication networks, the levels of electromagnetic contamination have risen dramatically in the recent years. Every day, new studies appear searching for a way to mitigate the electromagnetic interferences (EMI). At the same time, the rapid evolution of technology forces the field to search for lighter and more efficient materials. The composites using carbon allotropes (such as carbon nanotubes) and polymers as reinforcement are gaining importance, due to the many advantages they exhibit in comparison to the materials that were used until now. A great number of applications require absorption to be the main electromagnetic shielding mechanism, thereby making this review necessary as a way to summarize the latest studies on CNT/polymer composites and how to improve the absorption mechanism by changing the morphology and composition of CNTs

    Spheresomes are the main extracellular vesicles in low-grade gliomas

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    Cancer progression and its impact on treatment response and prognosis is deeply regulated by tumour microenvironment (TME). Cancer cells are in constant communication and modulate TME through several mechanisms, including transfer of tumour-promoting cargos through extracellular vesicles (EVs) or oncogenic signal detection by primary cilia. Spheresomes are a specific EV that arise from rough endoplasmic reticulum–Golgi vesicles. They accumulate beneath cell membrane and are released to the extracellular medium through multivesicular spheres. This study describes spheresomes in low-grade gliomas using electron microscopy. We found that spheresomes are more frequent than exosomes in these tumours and can cross the blood–brain barrier. Moreover, the distinct biogenesis processes of these EVs result in unique cargo profiles, suggesting different functional roles. We also identified primary cilia in these tumours. These findings collectively contribute to our understanding of glioma progression and metastasis

    Diseño de un producto enfocado al mantenimiento fisiológico en ambientes de microgravedad, en colaboración con la empresa Aureel

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    La exposición a ambientes micro-gravitacionales conlleva efectos perjudiciales sobre la fisiología humana. Es por ello que, este Proyecto consiste en la conceptualización, diseño y desarrollo de VIRGO-I, un Generador de Gravedad Artificial a Nivel Sanguíneo. Para ello, se han realizado cuatro fases de diseño: investigación, conceptualización, desarrollo técnico y formal y presentación del producto. El contenido de la investigación recoge aspectos necesarios para la comprensión e interpretación de lo referente a la gravedad y aspectos fisiológicos, y es contrastada con entrevistas a expertos, La fase de conceptualización se basa en la técnica de Brainstorming y Mind-map. Tras ello se elige uno de los conceptos mediante la Técnica Radar y se desarrollan las bases teóricas relativas a estudiar su viabilidad y funcionamiento. Finalmente, se realiza una presentación del producto final acompañada de la documentación técnica para su fabricación y presupuesto

    Carbon nanotube scaffolds with controlled porosity as electromagnetic absorbing materials in the gigahertz range

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    Control of the microscopic structure of CNT nanocomposites allows modulation of the electromagnetic shielding in the gigahertz range. The porosity of CNT scaffolds has been controlled by two freezing protocols and a subsequent lyophilization step: fast freezing in liquid nitrogen and slow freezing at −20 °C. Mercury porosimetry shows that slowly frozen specimens present a more open pore size (100–150 μm) with a narrow distribution whereas specimens frozen rapidly show a smaller pore size and a heterogeneous distribution. 3D-scaffolds containing 3, 4, 6 and 7% CNT were infiltrated with epoxy and specimens with 2, 5 and 8 mm thicknesses were characterized in the GHz range. Samples with the highest pore size and porosity presented the lowest reflected power (about 30%) and the highest absorbed power (about 70%), which allows considering them as electromagnetic radiation absorbing materials.This work was supported by grants NANOARQ (MAT2014-57557-R) from the Spanish Ministerio de Ciencia y Tecnologí

    Características de las mallas quirúrgicas sintéticas y su relación con el desarrollo de complicaciones posoperatorias.

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    La hernia incisional es una de las patologías abdominales subsidiarias de reparación quirúrgica más frecuentes. Hoy en día esta reparación puede realizarse mediante la implantación de una malla quirúrgica para reforzar el defecto herniario, y a pesar de conseguir mejores resultados que la reparación sin malla en cuanto a tasa de recidivas, también se han observado complicaciones como infección de la malla, seromas y adherencias.Mediante una revisión bibliográfica y la caracterización de 15 mallas quirúrgicas se obtiene información acerca de las complicaciones de este procedimiento y su relación con las características de las mallas.<br /

    Análisis de las posibilidades de desarrollo de un sistema de recogida de datos clínicos relacionados con el cáncer de mama

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    En el presente proyecto se ha realizado un análisis profundo de las posibilidades de proponer una mejora en el sistema de recogida de datos clínicos, relacionados con el cáncer de mama, en el Hospital Clínico Universitario Lozano Blesa.Como resultado de dicho análisis se propone diseñar un sistema completamente nuevo teniendo en cuenta las funciones más importantes de los sistemas actuales del hospital, así como implementar otras herramientas que faciliten la labor a los sanitarios especialistas.<br /

    Novel P-in-N Si-Sensor technology for high resolution and high repetition-rate experiments at accelerator facilities

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    Linear array detectors with high spatial resolution and MHz frame-rates are essential for high-rate experiments at accelerator facilities. KALYPSO, a line array detector with 1024 pixels operating over 1 Mfps has been developed. To improve the spatial resolution and sensitivity at different wavelengths, novel p-in-n Si microstrip sensors based on have been developed with a pitch of 25 micrometer. The efficiency of the sensor has been improved with the use of anti reflecting coating layers optimized for near infrared, visible and near ultraviolet. In this contribution the detector system and the sensors will be presented
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